Nature-based flood risk management -challenges in implementing catchment-wide management concepts

NASA Astrophysics Data System (ADS)

Thaler, Thomas; Fuchs, Sven

2017-04-01

Traditionally, flood risk management focused on coping with the flow at a given point by, for example, building dikes or straightening the watercourse. Increasingly the emphasis has shifted to measures within the flood plain to delay the flow through storage. As such the fluent boundaries imposed by the behaviour of the catchment at a certain point are relocated upstream by the human intervention. Therefore, the implementation of flood storages and the use of natural retention areas are promoted as mitigation measures to support sustainable flood risk management. They aimed at reducing the effluent boundaries on the floodplain by increasing the effluent boundaries upstream. However, beyond the simple change of practices it is indeed often a question of land use change which is at stake in water management. As such, it poses the questions on how to govern both water and land to satisfy the different stakeholders. Nature-based strategies often follow with voluntary agreements, which are promoted as an alternative instrument to the traditional top-down command and control regulation. Voluntary agreements aim at bringing more efficiency, participatory and transparency in solving problems between different social groups. In natural hazard risk management voluntary agreements are now receiving high interests to complement the existing policy instruments in order to achieve the objectives the EU WFD and of the Floods Directive. This paper investigates the use of voluntary agreements as an alternative instrument to the traditional top-down command and control regulation in the implementation of flood storages in Austria. The paper provides a framework of analysis to reveal barriers and opportunities associated with such approach. The paper concludes that institution and power are the central elements to tackle for allowing the success of voluntary agreement.

Variability in eddy sandbar dynamics during two decades of controlled flooding of the Colorado River in the Grand Canyon

USGS Publications Warehouse

Mueller, Erich R.; Grams, Paul E.; Hazel, Joseph E.; Schmidt, John C.

2018-01-01

Sandbars are iconic features of the Colorado River in the Grand Canyon, Arizona, U.S.A. Following completion of Glen Canyon Dam in 1963, sediment deficit conditions caused erosion of eddy sandbars throughout much of the 360 km study reach downstream from the dam. Controlled floods in 1996, 2004, and 2008 demonstrated that sand on the channel bed could be redistributed to higher elevations, and that floods timed to follow tributary sediment inputs would increase suspended sand concentrations during floods. Since 2012, a new management protocol has resulted in four controlled floods timed to follow large inputs of sand from a major tributary. Monitoring of 44 downstream eddy sandbars, initiated in 1990, shows that each controlled flood deposited significant amounts of sand and increased the size of subaerial sandbars. However, the magnitude of sandbar deposition varied from eddy to eddy, even over relatively short distances where main-stem suspended sediment concentrations were similar. Here, we characterize spatial and temporal trends in sandbar volume and site-scale (i.e., individual eddy) sediment storage as a function of flow, channel, and vegetation characteristics that reflect the reach-scale (i.e., kilometer-scale) hydraulic environment. We grouped the long-term monitoring sites based on geomorphic setting and used a principal component analysis (PCA) to correlate differences in sandbar behavior to changes in reach-scale geomorphic metrics. Sites in narrow reaches are less-vegetated, stage changes markedly with discharge, sandbars tend to remain dynamic, and sand storage change dominantly occurs in the eddy compared to the main channel. In wider reaches, where stage-change during floods may be half that of narrow sites, sandbars are more likely to be stabilized by vegetation, and floods tend to aggrade the vegetated sandbar surfaces. In these locations, deposition during controlled floods is more akin to floodplain sedimentation, and the elevation of sandbar surfaces increases with successive floods. Because many sandbars are intermediate to the end members described above, high-elevation bar surfaces stabilized by vegetation often have a more dynamic unvegetated sandbar on the channel-ward margin that aggrades and erodes in response to controlled flood cycles. Ultimately, controlled floods have been effective at increasing averaged sandbar volumes, and, while bar deposition during floods decreases through time where vegetation has stabilized sandbars, future controlled floods are likely to continue to result in deposition in a majority of the river corridor.

76 FR 17019 - List of Approved Spent Fuel Storage Casks: HI-STORM Flood/Wind Addition

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-28

... Storage Casks: HI-STORM Flood/Wind Addition AGENCY: Nuclear Regulatory Commission. ACTION: Direct final... regulations to add the HI-STORM Flood/Wind cask system to the ``List of Approved Spent Fuel Storage Casks... cask designs. Discussion This rule will add the Holtec HI-STORM Flood/Wind (FW) cask system to the list...

A method of measuring increase in soil depth and water-storage capacity due to forest management

Treesearch

George R., Jr. Trimble

1952-01-01

Conservationists, engineers, and others who deal with water problems have become more and more concerned in recent years with increasing the storage of water in the ground. Their concern has centered around problems of flood control and storage of water for later use by plants or animals, including man.

76 FR 33121 - List of Approved Spent Fuel Storage Casks: HI-STORM Flood/Wind Addition

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-08

... Storage Casks: HI-STORM Flood/Wind Addition AGENCY: Nuclear Regulatory Commission. ACTION: Direct final... regulations to add the Holtec HI-STORM Flood/Wind cask system to the ``List of Approved Spent Fuel Storage... Title 10 of the Code of Federal Regulations Section 72.214 to add the Holtec HI- STORM Flood/Wind cask...

Nonlinear Filtering Effects of Reservoirs on Flood Frequency Curves at the Regional Scale: RESERVOIRS FILTER FLOOD FREQUENCY CURVES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Wei; Li, Hong-Yi; Leung, L. Ruby

Anthropogenic activities, e.g., reservoir operation, may alter the characteristics of Flood Frequency Curve (FFC) and challenge the basic assumption of stationarity used in flood frequency analysis. This paper presents a combined data-modeling analysis of the nonlinear filtering effects of reservoirs on the FFCs over the contiguous United States. A dimensionless Reservoir Impact Index (RII), defined as the total upstream reservoir storage capacity normalized by the annual streamflow volume, is used to quantify reservoir regulation effects. Analyses are performed for 388 river stations with an average record length of 50 years. The first two moments of the FFC, mean annual maximummore » flood (MAF) and coefficient of variations (CV), are calculated for the pre- and post-dam periods and compared to elucidate the reservoir regulation effects as a function of RII. It is found that MAF generally decreases with increasing RII but stabilizes when RII exceeds a threshold value, and CV increases with RII until a threshold value beyond which CV decreases with RII. The processes underlying the nonlinear threshold behavior of MAF and CV are investigated using three reservoir models with different levels of complexity. All models capture the non-linear relationships of MAF and CV with RII, suggesting that the basic flood control function of reservoirs is key to the non-linear relationships. The relative roles of reservoir storage capacity, operation objectives, available storage prior to a flood event, and reservoir inflow pattern are systematically investigated. Our findings may help improve flood-risk assessment and mitigation in regulated river systems at the regional scale.« less

Variability in eddy sandbar dynamics during two decades of controlled flooding of the Colorado River in the Grand Canyon

NASA Astrophysics Data System (ADS)

Mueller, Erich R.; Grams, Paul E.; Hazel, Joseph E.; Schmidt, John C.

2018-01-01

Sandbars are iconic features of the Colorado River in the Grand Canyon, Arizona, U.S.A. Following completion of Glen Canyon Dam in 1963, sediment deficit conditions caused erosion of eddy sandbars throughout much of the 360 km study reach downstream from the dam. Controlled floods in 1996, 2004, and 2008 demonstrated that sand on the channel bed could be redistributed to higher elevations, and that floods timed to follow tributary sediment inputs would increase suspended sand concentrations during floods. Since 2012, a new management protocol has resulted in four controlled floods timed to follow large inputs of sand from a major tributary. Monitoring of 44 downstream eddy sandbars, initiated in 1990, shows that each controlled flood deposited significant amounts of sand and increased the size of subaerial sandbars. However, the magnitude of sandbar deposition varied from eddy to eddy, even over relatively short distances where main-stem suspended sediment concentrations were similar. Here, we characterize spatial and temporal trends in sandbar volume and site-scale (i.e., individual eddy) sediment storage as a function of flow, channel, and vegetation characteristics that reflect the reach-scale (i.e., kilometer-scale) hydraulic environment. We grouped the long-term monitoring sites based on geomorphic setting and used a principal component analysis (PCA) to correlate differences in sandbar behavior to changes in reach-scale geomorphic metrics. Sites in narrow reaches are less-vegetated, stage changes markedly with discharge, sandbars tend to remain dynamic, and sand storage change dominantly occurs in the eddy compared to the main channel. In wider reaches, where stage-change during floods may be half that of narrow sites, sandbars are more likely to be stabilized by vegetation, and floods tend to aggrade the vegetated sandbar surfaces. In these locations, deposition during controlled floods is more akin to floodplain sedimentation, and the elevation of sandbar surfaces increases with successive floods. Because many sandbars are intermediate to the end members described above, high-elevation bar surfaces stabilized by vegetation often have a more dynamic unvegetated sandbar on the channel-ward margin that aggrades and erodes in response to controlled flood cycles. Ultimately, controlled floods have been effective at increasing averaged sandbar volumes, and, while bar deposition during floods decreases through time where vegetation has stabilized sandbars, future controlled floods are likely to continue to result in deposition in a majority of the river corridor. Supplementary Fig. 2 Relation between the total site and high-elevation discharge-volume relation slope for all sites where both relations are available (n = 33). Supplementary Fig. 3 Change in sandbar volume since 1990 for Marble versus Grand Canyon sites. Solid vertical gray lines indicate controlled floods, and dashed vertical gray lines indicate other high test flows in 1997 and 2000 as discussed in the text. ​Photographs by U.S. Geological Survey, 2008-2015.

The Impact of Corps Flood Control Reservoirs in the June 2008 Upper Mississippi Flood

NASA Astrophysics Data System (ADS)

Charley, W. J.; Stiman, J. A.

2008-12-01

The US Army Corps of Engineers is responsible for a multitude of flood control project on the Mississippi River and its tributaries, including levees that protect land from flooding, and dams to help regulate river flows. The first six months of 2008 were the wettest on record in the upper Mississippi Basin. During the first 2 weeks of June, rainfall over the Midwest ranged from 6 to as much as 16 inches, overwhelming the flood protection system, causing massive flooding and damage. Most severely impacted were the States of Iowa, Illinois, Indiana, Missouri, and Wisconsin. In Iowa, flooding occurred on almost every river in the state. On the Iowa River, record flooding occurred from Marshalltown, Iowa, downstream to its confluence with the Mississippi River. At several locations, flooding exceeded the 500-year event. The flooding affected agriculture, transportation, and infrastructure, including homes, businesses, levees, and other water-control structures. It has been estimated that there was at least 7 billion dollars in damages. While the flooding in Iowa was extraordinary, Corps of Engineers flood control reservoirs helped limit damage and prevent loss of life, even though some reservoirs were filled beyond their design capacity. Coralville Reservoir on the Iowa River, for example, filled to 135% of its design flood storage capacity, with stage a record five feet over the crest of the spillway. In spite of this, the maximum reservoir release was limited to 39,500 cfs, while a peak inflow of 57,000 cfs was observed. CWMS, the Corps Water Management System, is used to help regulate Corps reservoirs, as well as track and evaluate flooding and flooding potential. CWMS is a comprehensive data acquisition and hydrologic modeling system for short-term decision support of water control operations in real time. It encompasses data collection, validation and transformation, data storage, visualization, real time model simulation for decision-making support, and data dissemination. The system uses precipitation and flow data, collected in real-time, along with forecasted flow from the National Weather Service to model and optimize reservoir operations and forecast downstream flows and stages, providing communities accurate and timely information to aid their flood-fighting. This involves integrating several simulation modeling programs, including HEC-HMS to forecast flows, HEC-ResSim to model reservoir operations and HEC-RAS to compute forecasted stage hydrographs. An inundation boundary and depth map of water in the flood plain can be calculated from the HEC-RAS results using ArcInfo. By varying future precipitation and releases, engineers can evaluate different "What if?" scenarios. The effectiveness of this tool and Corps reservoirs are examined.

Process-based model with flood control measures towards more realistic global flood modeling

NASA Astrophysics Data System (ADS)

Tang, Q.; Zhang, X.; Wang, Y.; Mu, M.; Lv, A.; Li, Z.

2017-12-01

In the profoundly human-influenced era, the Anthropocene, increased amount of land was developed in flood plains and many flood control measures were implemented to protect people and infrastructures placed in the flood-prone areas. These human influences (for example, dams and dykes) have altered peak streamflow and flood risk, and are already an integral part of flood. However, most of the process-based flood models have yet to taken into account the human influences. In this study, we used a hydrological model together with an advanced hydrodynamic model to assess flood risk at the Baiyangdian catchment. The Baiyangdian Lake is the largest shallow freshwater lake in North China, and it was used as a flood storage area in the past. A new development hub for the Beijing-Tianjin-Hebei economic triangle, namely the Xiongan new area, was recently established in the flood-prone area around the lake. The shuttle radar topography mission (SRTM) digital elevation model (DEMs) was used to parameterize the hydrodynamic model simulation, and the inundation estimates were compared with published flood maps and observed inundation area during the extreme historical flood events. A simple scheme was carried out to consider the impacts of flood control measures, including the reservoirs in the headwaters and the dykes to be built. By comparing model simulations with and without the influences of flood control measures, we demonstrated the importance of human influences in altering the inundated area and depth under design flood conditions. Based on the SRTM DEM and dam and reservoir data in the Global Reservoir and Dam (GRanD) database, we further discuss the potential to develop a global flood model with human influences.

The use of Natural Flood Management to mitigate local flooding in the rural landscape

NASA Astrophysics Data System (ADS)

Wilkinson, Mark; Quinn, Paul; Ghimire, Sohan; Nicholson, Alex; Addy, Steve

2014-05-01

The past decade has seen increases in the occurrence of flood events across Europe, putting a growing number of settlements of varying sizes at risk. The issue of flooding in smaller villages is usually not well publicised. In these small communities, the cost of constructing and maintaining traditional flood defences often outweigh the potential benefits, which has led to a growing quest for more cost effective and sustainable approaches. Here we aim to provide such an approach that alongside flood risk reduction, also has multipurpose benefits of sediment control, water quality amelioration, and habitat creation. Natural flood management (NFM) aims to reduce flooding by working with natural features and characteristics to slow down or temporarily store flood waters. NFM measures include dynamic water storage ponds and wetlands, interception bunds, channel restoration and instream wood placement, and increasing soil infiltration through soil management and tree planting. Based on integrated monitoring and modelling studies, we demonstrate the potential to manage runoff locally using NFM in rural systems by effectively managing flow pathways (hill slopes and small channels) and by exploiting floodplains and buffers strips. Case studies from across the UK show that temporary storage ponds (ranging from 300 to 3000m3) and other NFM measures can reduce peak flows in small catchments (5 to 10 km2) by up to 15 to 30 percent. In addition, increasing the overall effective storage capacity by a network of NFM measures was found to be most effective for total reduction of local flood peaks. Hydraulic modelling has shown that the positioning of such features within the catchment, and how they are connected to the main channel, may also affect their effectiveness. Field evidence has shown that these ponds can collect significant accumulations of fine sediment during flood events. On the other hand, measures such as wetlands could also play an important role during low flow conditions, by providing base flows during drought conditions. Ongoing research using hydrological datasets aims to assess how these features function during low flow conditions and how storage ponds could be used as irrigation ponds in arable areas. To allow for effective implementation and upkeep of NFM measures on the ground, demonstration sites have been developed through a process of iterative stakeholder engagement. Coupled with the use of novel visualisation techniques, results are currently being communicated to a wider community of local landowners and catchment managers. The approach of using networks of interception bunds and offline storage areas in the rural landscape could potentially provide a cost effective means to reduce flood risk in small responsive catchments across Europe. As such it could provide an alternative or addition to traditional engineering techniques, while also effectively managing catchments to achieve multiple environmental objectives.

Natural Flood Management Plus: Scaling Up Nature Based Solutions to Larger Catchments

NASA Astrophysics Data System (ADS)

Quinn, Paul; Nicholson, Alex; Adams, Russ

2017-04-01

It has been established that networks NFM features, such as ponds and wetlands, can have a significant effect on flood flow and pollution at local scales (less than 10km2). However, it is much less certain that NFM and NBS can impact at larger scales and protect larger cities. This is especially true for recent storms in the UK such as storm Desmond that caused devastation across the north of England. It is possible using observed rainfall and runoff data to estimate the amounts of storage that would be required to impact on extreme flood events. Here we will how a toolkit that will estimate the amount of storage that can be accrued through a dense networks of NFM features. The analysis suggest that the use of many hundreds of small NFM features can have a significant impact on peak flow, however we still require more storage in order to address extreme events and to satisfy flood engineers who may propose more traditional flood defences. We will also show case studies of larger NFM feature positioned on flood plains that can store significantly more flood flow. Examples designs of NFM plus feature will be shown. The storage aggregation tool will then show the degree to which storing large amounts of flood flow in NFM plus features can contribute to flood management and estimate the likely costs. Together smaller and larger NFM features if used together can produce significant flood storage and at a much lower cost than traditional schemes.

Effect of soil and cover conditions on soil-water relationships

Treesearch

George R., Jr. Trimble; Charles E. Hale; H. Spencer Potter

1951-01-01

People who make flood-control surveys for the U.S. Department of Agriculture are concerned with the physical condition of the soils in the watersheds. The condition of the soil determines how fast water moves into and through the soil, and how much water is held in storage. The condition of the soil has a great influence on stream flow, erosion, floods and water supply...

American River Watershed Investigation, California. Reconnaisance Report

DTIC Science & Technology

1988-01-01

studies, and (4) identification of a non-federal sponsor for the feasibility study. The primary study area included the lower American River between Nimbus...FEMA), is r’esponsible for administering the National Flood Insurance Program (NFIP).. A basic goal of the NFIP is the identification of flood plain...RESERVO]R - RE:QUIRED FLOOD COVfIROL SPACI (1,000 ac--ft) Level of Protection Total Flood Folsom Flood New Upstream (Return Period - Storage Storage 2

Understanding Flood Seasonality and Its Temporal Shifts within the Contiguous United States

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ye, Sheng; Li, Hong-Yi; Leung, L. Ruby

2017-07-01

Understanding the causes of flood seasonality is critical for better flood management. This study examines the seasonality of annual maximum floods (AMF) and its changes before and after 1980 at over 250 natural catchments across the contiguous United States. Using circular statistics to define a seasonality index, our analysis focuses on the variability of the flood occurrence date. Generally, catchments with more synchronized seasonal water and energy cycles largely inherit their seasonality of AMF from that of annual maximum rainfall (AMR). In contrast, the seasonality of AMF in catchments with loosely synchronized water and energy cycles are more influenced bymore » high antecedent storage, which is responsible for the amplification of the seasonality of AMF over that of AMR. This understanding then effectively explains a statistically significant shift of flood seasonality detected in some catchments in the recent decades. Catchments where the antecedent soil water storage has increased since 1980 exhibit increasing flood seasonality while catchments that have experienced increases in storm rainfall before the floods have shifted towards floods occurring more variably across the seasons. In the eastern catchments, a concurrent widespread increase in event rainfall magnitude and reduced soil water storage have led to a more variable timing of floods. Our findings of the role of antecedent storage and event rainfall on the flood seasonality provide useful insights for understanding future changes in flood seasonality as climate models projected changes in extreme precipitation and aridity over land.« less

Hydrologic control of nitrogen removal, storage, and export in a mountain stream

USGS Publications Warehouse

Hall, R.O.; Baker, M.A.; Arp, C.D.; Kocha, B.J.

2009-01-01

Nutrient cycling and export in streams and rivers should vary with flow regime, yet most studies of stream nutrient transformation do not include hydrologic variability. We used a stable isotope tracer of nitrogen (15N) to measure nitrate (NO3) uptake, storage, and export in a mountain stream, Spring Creek, Idaho, U.S.A. We conducted two tracer tests of 2-week duration during snowmelt and baseflow. Dissolved and particulate forms of 15N were monitored over three seasons to test the hypothesis that stream N cycling would be dominated by export during floods, and storage during low flow. Floods exported more N than during baseflow conditions; however, snowmelt floods had higher than expected demand for NO{3 because of hyporheic exchange. Residence times of benthic N during both tracer tests were longer than 100 d for ephemeral pools such as benthic algae and wood biofilms. Residence times were much longer in fine detritus, insects, and the particulate N from the hyporheic zone, showing that assimilation and hydrologic storage can be important mechanisms for retaining particulate N. Of the tracer N stored in the stream, the primary form of export was via seston during periods of high flows, produced by summer rainstorms or spring snowmelt the following year. Spring Creek is not necessarily a conduit for nutrients during high flow; hydrologic exchange between the stream and its valley represents an important storage mechanism.

Bassett Creek Watershed, Hennepin County, Minnesota. Feasibility Report for Control. Appendixes.

DTIC Science & Technology

1976-03-01

maintenance of the creek corridor . The local interests objected to any plan that would impair the aesthetics of the creek. The needs of the watershed with...OPEN CHANNEL CORRIDOR TO THE MISSISSIPPI RIVR (Alternate 5-E) ...... .............. D-26 COMBINATIONS OF NONSTRUCTURAL AND STRUCTURAL ALTERNATIVES...AND DRE TURNEL (Alternate 6-D) . . ... . . . . . . . . . . D-30 FLOOD STORAGE AND FLOOD PROOFIM. WIT7 AN O(IUI SPACE-- OPEN CHANNEL CORRIDOR TO THE

Feasibility Report and Final Environmental Impact Statement, Wisconsin River at Portage, Wisconsin, Feasibility Study for Flood Control. Appendixes.

DTIC Science & Technology

1983-12-01

therefore, any possible changes in floodplain regulation would be independent of project implementation. The existing regulation affects properties...to 0.4. Based on engineering experience there is a tendency toward independence as tributary drainage area size decreases. Frequency-discharge...stages on the Wisconsin River. Similarly the storage areas are analyzed as independent syste,, o thereby, reduction in flood elevations (routing) and

The response of source-bordering aeolian dunefields to sediment-supply changes 2: Controlled floods of the Colorado River in Grand Canyon, Arizona, USA

USGS Publications Warehouse

Sankey, Joel B.; Caster, Joshua; Kasprak, Alan; East, Amy

2018-01-01

In the Colorado River downstream of Glen Canyon Dam in the Grand Canyon, USA, controlled floods are used to resupply sediment to, and rebuild, river sandbars that have eroded severely over the past five decades owing to dam-induced changes in river flow and sediment supply. In this study, we examine whether controlled floods, can in turn resupply aeolian sediment to some of the large source-bordering aeolian dunefields (SBDs) along the margins of the river. Using a legacy of high-resolution lidar remote-sensing and meteorological data, we characterize the response of four SBDs (a subset of 117 SBDs and other aeolian-sand-dominated areas in the canyon) during four sediment-laden controlled floods of the Colorado River in 2012, 2013, 2014, and 2016. We find that aeolian sediment resupply unambiguously occurred in 8 of the 16 instances of controlled flooding adjacent to SBDs. Resupply attributed to individual floods varied substantially among sites, and occurred with four, three, one, and zero floods at the four sites, respectively. We infer that the relative success of controlled floods as a regulated-river management tool for resupplying sediment to SBDs is analogous to the frequency of resupply observed for fluvial sandbars in this setting, in that sediment resupply was estimated to have occurred for roughly half of the instances of recent controlled flooding at sandbars monitored separately from this study. We find the methods developed in this, and a companion study, are effective tools to quantify geomorphic changes in sediment storage, along linked fluvial and aeolian pathways of sedimentary systems.

The response of source-bordering aeolian dunefields to sediment-supply changes 2: Controlled floods of the Colorado River in Grand Canyon, Arizona, USA

NASA Astrophysics Data System (ADS)

Sankey, Joel B.; Caster, Joshua; Kasprak, Alan; East, Amy E.

2018-06-01

In the Colorado River downstream of Glen Canyon Dam in the Grand Canyon, USA, controlled floods are used to resupply sediment to, and rebuild, river sandbars that have eroded severely over the past five decades owing to dam-induced changes in river flow and sediment supply. In this study, we examine whether controlled floods, can in turn resupply aeolian sediment to some of the large source-bordering aeolian dunefields (SBDs) along the margins of the river. Using a legacy of high-resolution lidar remote-sensing and meteorological data, we characterize the response of four SBDs (a subset of 117 SBDs and other aeolian-sand-dominated areas in the canyon) during four sediment-laden controlled floods of the Colorado River in 2012, 2013, 2014, and 2016. We find that aeolian sediment resupply unambiguously occurred in 8 of the 16 instances of controlled flooding adjacent to SBDs. Resupply attributed to individual floods varied substantially among sites, and occurred with four, three, one, and zero floods at the four sites, respectively. We infer that the relative success of controlled floods as a regulated-river management tool for resupplying sediment to SBDs is analogous to the frequency of resupply observed for fluvial sandbars in this setting, in that sediment resupply was estimated to have occurred for roughly half of the instances of recent controlled flooding at sandbars monitored separately from this study. We find the methods developed in this, and a companion study, are effective tools to quantify geomorphic changes in sediment storage, along linked fluvial and aeolian pathways of sedimentary systems.

Multiobjective hedging rules for flood water conservation

NASA Astrophysics Data System (ADS)

Ding, Wei; Zhang, Chi; Cai, Ximing; Li, Yu; Zhou, Huicheng

2017-03-01

Flood water conservation can be beneficial for water uses especially in areas with water stress but also can pose additional flood risk. The potential of flood water conservation is affected by many factors, especially decision makers' preference for water conservation and reservoir inflow forecast uncertainty. This paper discusses the individual and joint effects of these two factors on the trade-off between flood control and water conservation, using a multiobjective, two-stage reservoir optimal operation model. It is shown that hedging between current water conservation and future flood control exists only when forecast uncertainty or decision makers' preference is within a certain range, beyond which, hedging is trivial and the multiobjective optimization problem is reduced to a single objective problem with either flood control or water conservation. Different types of hedging rules are identified with different levels of flood water conservation preference, forecast uncertainties, acceptable flood risk, and reservoir storage capacity. Critical values of decision preference (represented by a weight) and inflow forecast uncertainty (represented by standard deviation) are identified. These inform reservoir managers with a feasible range of their preference to water conservation and thresholds of forecast uncertainty, specifying possible water conservation within the thresholds. The analysis also provides inputs for setting up an optimization model by providing the range of objective weights and the choice of hedging rule types. A case study is conducted to illustrate the concepts and analyses.

Flood management on the lower Yellow River: hydrological and geomorphological perspectives

NASA Astrophysics Data System (ADS)

Shu, Li; Finlayson, Brian

1993-05-01

The Yellow River, known also as "China's Sorrow", has a long history of channel changes and disastrous floods in its lower reaches. Past channel positions can be identified from historical documentary records and geomorphological and sedimentological evidence. Since 1947, government policy has been aimed at containing the floods within artificial levees and preventing the river from changing its course. Flood control is based on flood-retarding dams and off-stream retention basins as well as artificial levees lining the channel. The design flood for the system has a recurrence interval of only around 60 years and floods of this and larger magnitudes can be generated downstream of the main flood control dams at Sanmenxia and Xiaolangdi. Rapid sedimentation along the river causes problems for storage and has raised the bed of the river some 10 m above the surrounding floodplain. The present management strategy is probably not viable in the long term and to avoid a major disaster a new management approach is required. The most viable option would appear to be to breach the levees at predetermined points coupled with advanced warning and evacuation of the population thus put at risk.

18 CFR 1304.405 - Fuel storage tanks and handling facilities.

Code of Federal Regulations, 2012 CFR

2012-04-01

... State showing how the tank will be anchored so that it does not float during flooding; and (5) Evidence, where applicable, that the applicant has complied with all spill prevention, control and countermeasures...

18 CFR 1304.405 - Fuel storage tanks and handling facilities.

Code of Federal Regulations, 2013 CFR

2013-04-01

... State showing how the tank will be anchored so that it does not float during flooding; and (5) Evidence, where applicable, that the applicant has complied with all spill prevention, control and countermeasures...

18 CFR 1304.405 - Fuel storage tanks and handling facilities.

Code of Federal Regulations, 2014 CFR

2014-04-01

... State showing how the tank will be anchored so that it does not float during flooding; and (5) Evidence, where applicable, that the applicant has complied with all spill prevention, control and countermeasures...

18 CFR 1304.405 - Fuel storage tanks and handling facilities.

Code of Federal Regulations, 2011 CFR

2011-04-01

... State showing how the tank will be anchored so that it does not float during flooding; and (5) Evidence, where applicable, that the applicant has complied with all spill prevention, control and countermeasures...

18 CFR 1304.405 - Fuel storage tanks and handling facilities.

Code of Federal Regulations, 2010 CFR

2010-04-01

... State showing how the tank will be anchored so that it does not float during flooding; and (5) Evidence, where applicable, that the applicant has complied with all spill prevention, control and countermeasures...

Tropical stormwater floods: a sustainable solution

NASA Astrophysics Data System (ADS)

Molinie, Jack; Bade, Francois; Nagau, Jimmy; Nuiro, Paul

2017-04-01

Stormwater management is one of the most difficult problem of urban and suburban area. The urban runoff volume related to rain intensity and surfaces properties can lead to flood. Thereby, urban flooding creates considerable infrastructure problem, economics and human damages. In tropical countries, burgeoning human population coupled with unplanned urbanization altered the natural drainage. Consequently, classical intense rain around 100 cm/h produces frequent street flooding. In our case, we study the management of intense tropical rain, by using a network of individual rain storage tanks. The study area is economical and industrial zone installed in a coastal plain , with seventy per cent of impermeable surface (roads, parking lots, building roof, …) and thirty per cent of wetland (mangrove, …). Our solution is to delay the routes and parking lots runoff to the roof one. We propose sustainable individual water storage and a real time dynamical management, which permit to control the roof water arrival in the stormwater culvert. During the remaining time, the stored rainwater can be used for domestic activities instead of the use of drinking water.

Global SWOT Data Assimilation of River Hydrodynamic Model; the Twin Simulation Test of CaMa-Flood

NASA Astrophysics Data System (ADS)

Ikeshima, D.; Yamazaki, D.; Kanae, S.

2016-12-01

CaMa-Flood is a global scale model for simulating hydrodynamics in large scale rivers. It can simulate river hydrodynamics such as river discharge, flooded area, water depth and so on by inputting water runoff derived from land surface model. Recently many improvements at parameters or terrestrial data are under process to enhance the reproducibility of true natural phenomena. However, there are still some errors between nature and simulated result due to uncertainties in each model. SWOT (Surface water and Ocean Topography) is a satellite, which is going to be launched in 2021, can measure open water surface elevation. SWOT observed data can be used to calibrate hydrodynamics model at river flow forecasting and is expected to improve model's accuracy. Combining observation data into model to calibrate is called data assimilation. In this research, we developed data-assimilated river flow simulation system in global scale, using CaMa-Flood as river hydrodynamics model and simulated SWOT as observation data. Generally at data assimilation, calibrating "model value" with "observation value" makes "assimilated value". However, the observed data of SWOT satellite will not be available until its launch in 2021. Instead, we simulated the SWOT observed data using CaMa-Flood. Putting "pure input" into CaMa-Flood produce "true water storage". Extracting actual daily swath of SWOT from "true water storage" made simulated observation. For "model value", we made "disturbed water storage" by putting "noise disturbed input" to CaMa-Flood. Since both "model value" and "observation value" are made by same model, we named this twin simulation. At twin simulation, simulated observation of "true water storage" is combined with "disturbed water storage" to make "assimilated value". As the data assimilation method, we used ensemble Kalman filter. If "assimilated value" is closer to "true water storage" than "disturbed water storage", the data assimilation can be marked effective. Also by changing the input disturbance of "disturbed water storage", acceptable rate of uncertainty at the input may be discussed.

Analysis of the Tonle Sap Flood Pulse Based on Remote Sensing: how much does Tonle Sap Lake Affect the Mekong River Flood?

NASA Astrophysics Data System (ADS)

Qu, W.; Hu, N.; Fu, J.; Lu, J.; Lu, H.; Lei, T.; Pang, Z.; Li, X.; Li, L.

2018-04-01

The economic value of the Tonle Sap Lake Floodplain to Cambodia is among the highest provided to a nation by a single ecosystem around the world. The flow of Mekong River is the primary factor affecting the Tonle Sap Lake Floodplain. The Tonle Sap Lake also plays a very important role in regulating the downstream flood of Mekong River. Hence, it is necessary to understand its temporal changes of lake surface and water storage and to analyse its relation with the flood processes of Mekong River. Monthly lake surface and water storage from July 2013 to May 2014 were first monitored based on remote sensing data. The relationship between water surface and accumulative water storage change was then established. In combination with hydrological modelling results of Mekong River Basin, the relation between the lake's water storage and the runoff of Mekong River was analysed. It is found that the water storage has a sharp increase from September to December and, after reaching its maximum in December, water storage quickly decreases with a 38.8 billion m3 of drop in only half month time from December to January, while it keeps rather stable at a lower level in other months. There is a two months' time lag between the maximum lake water storage and the Mekong River peak flood, which shows the lake's huge flood regulation role to downstream Mekong River. It shows that this remote sensing approach is feasible and reliable in quantitative monitoring of data scarce lakes.

Risk factors of diarrhoea among flood victims: a controlled epidemiological study.

PubMed

Mondal, N C; Biswas, R; Manna, A

2001-01-01

The concept and practice of 'disaster preparedness and response', instead of traditional casualty relief, is relatively new. Vulnerability analysis and health risks assessment of disaster prone communities are important prerequisites of meaningful preparedness and effective response against any calamity. In this community based study, the risk of diarrhoeal disease and its related epidemiological factors were analysed by collecting data from two selected flood prone block of Midnapur district of West Bengal. The information was compared with that of another population living in two non-flood prone blocks of the same district. The study showed that diarrhoeal disease was the commonest morbidity in flood prone population. Some behaviours, like use of pond water for utensil wash and kitchen purpose, hand washing after defecation without soap, improper hand washing before eating, open field defecation, storage of drinking water in wide mouth vessels etc. were found to be associated with high attack rate of diarrhoea, in both study and control population during flood season compared to pre-flood season. Attack rates were also significantly higher in flood prone population than that of population in non-flood prone area during the same season. Necessity of both community education for proper water use behaviour and personal hygiene along with ensuring safe water and sanitation facilities of flood affected communities were emphasized.

Evaluating the Implications of Climate Phenomenon Indices in Supporting Reservoir Operation Using the Artificial Neural Network and Decision-Tree Methods: A Case Study on Trinity Lake in Northern California

NASA Astrophysics Data System (ADS)

Yang, T.; Akbari Asanjan, A.; Gao, X.; Sorooshian, S.

2016-12-01

Reservoirs are fundamental human-built infrastructures that collect, store, and deliver fresh surface water in a timely manner for all kinds of purposes, including residential and industrial water supply, flood control, hydropower, and irrigation, etc. Efficient reservoir operation requires that policy makers and operators understand how reservoir inflows, available storage, and discharges are changing under different climatic conditions. Over the last decade, the uses of Artificial Intelligence and Data Mining (AI & DM) techniques in assisting reservoir management and seasonal forecasts have been increasing. Therefore, in this study, two distinct AI & DM methods, Artificial Neural Network (ANN) and Random Forest (RF), are employed and compared with respect to their capabilities of predicting monthly reservoir inflow, managing storage, and scheduling reservoir releases. A case study on Trinity Lake in northern California is conducted using long-term (over 50 years) reservoir operation records and 17 known climate phenomenon indices, i.e. PDO and ENSO, etc., as predictors. Results show that (1) both ANN and RF are capable of providing reasonable monthly reservoir storage, inflow, and outflow prediction with satisfactory statistics, and (2) climate phenomenon indices are useful in assisting monthly or seasonal forecasts of reservoir inflow and outflow. It is also found that reservoir storage has a consistent high autocorrelation effect, while inflow and outflow are more likely to be influenced by climate conditions. Using a Gini diversity index, RF method identifies that the reservoir discharges are associated with Southern Oscillation Index (SOI) and reservoir inflows are influenced by multiple climate phenomenon indices during different seasons. Furthermore, results also show that, during the winter season, reservoir discharges are controlled by the storage level for flood-control purposes, while, during the summer season, the flood-control operation is not as significant as that in the winter. With regard to the suitability of the AI & DM methods in support of reservoir operation, the Decision Tree method is suggested for future reservoir studies because of its transparency and non-parametric features over the "black-box" style ANN regression model.

Operational water management of Rijnland water system and pilot of ensemble forecasting system for flood control

NASA Astrophysics Data System (ADS)

van der Zwan, Rene

2013-04-01

The Rijnland water system is situated in the western part of the Netherlands, and is a low-lying area of which 90% is below sea-level. The area covers 1,100 square kilometres, where 1.3 million people live, work, travel and enjoy leisure. The District Water Control Board of Rijnland is responsible for flood defence, water quantity and quality management. This includes design and maintenance of flood defence structures, control of regulating structures for an adequate water level management, and waste water treatment. For water quantity management Rijnland uses, besides an online monitoring network for collecting water level and precipitation data, a real time control decision support system. This decision support system consists of deterministic hydro-meteorological forecasts with a 24-hr forecast horizon, coupled with a control module that provides optimal operation schedules for the storage basin pumping stations. The uncertainty of the rainfall forecast is not forwarded in the hydrological prediction. At this moment 65% of the pumping capacity of the storage basin pumping stations can be automatically controlled by the decision control system. Within 5 years, after renovation of two other pumping stations, the total capacity of 200 m3/s will be automatically controlled. In critical conditions there is a need of both a longer forecast horizon and a probabilistic forecast. Therefore ensemble precipitation forecasts of the ECMWF are already consulted off-line during dry-spells, and Rijnland is running a pilot operational system providing 10-day water level ensemble forecasts. The use of EPS during dry-spells and the findings of the pilot will be presented. Challenges and next steps towards on-line implementation of ensemble forecasts for risk-based operational management of the Rijnland water system will be discussed. An important element in that discussion is the question: will policy and decision makers, operator and citizens adapt this Anticipatory Water management, including temporary lower storage basin levels and a reduction in extra investments for infrastructural measures.

A new method, with application, for analysis of the impacts on flood risk of widely distributed enhanced hillslope storage

NASA Astrophysics Data System (ADS)

Metcalfe, Peter; Beven, Keith; Hankin, Barry; Lamb, Rob

2018-04-01

Enhanced hillslope storage is utilised in natural flood management in order to retain overland storm run-off and to reduce connectivity between fast surface flow pathways and the channel. Examples include excavated ponds, deepened or bunded accumulation areas, and gullies and ephemeral channels blocked with wooden barriers or debris dams. The performance of large, distributed networks of such measures is poorly understood. Extensive schemes can potentially retain large quantities of run-off, but there are indications that much of their effectiveness can be attributed to desynchronisation of sub-catchment flood waves. Inappropriately sited measures may therefore increase, rather than mitigate, flood risk. Fully distributed hydrodynamic models have been applied in limited studies but introduce significant computational complexity. The longer run times of such models also restrict their use for uncertainty estimation or evaluation of the many potential configurations and storm sequences that may influence the timings and magnitudes of flood waves. Here a simplified overland flow-routing module and semi-distributed representation of enhanced hillslope storage is developed. It is applied to the headwaters of a large rural catchment in Cumbria, UK, where the use of an extensive network of storage features is proposed as a flood mitigation strategy. The models were run within a Monte Carlo framework against data for a 2-month period of extreme flood events that caused significant damage in areas downstream. Acceptable realisations and likelihood weightings were identified using the GLUE uncertainty estimation framework. Behavioural realisations were rerun against the catchment model modified with the addition of the hillslope storage. Three different drainage rate parameters were applied across the network of hillslope storage. The study demonstrates that schemes comprising widely distributed hillslope storage can be modelled effectively within such a reduced complexity framework. It shows the importance of drainage rates from storage features while operating through a sequence of events. We discuss limitations in the simplified representation of overland flow-routing and representation and storage, and how this could be improved using experimental evidence. We suggest ways in which features could be grouped more strategically and thus improve the performance of such schemes.

Bassett Creek Watershed, Hennepin County, Minnesota. Feasibility Report for Flood Control. Main Report.

DTIC Science & Technology

1982-09-01

and storage yard owned by the Burlington Northern Railroad. The latter tract is covered predominantly by invader plant species , with only a few trees ...vegetation. Beautification Measures - The planting of flood-tolerant species of trees and shrubs to restore this area is recommended. See plate G-4i for...PLANT SPECIES TO BE INCLUDED IN THIS AREA INCLUDE: TREES GREEN ASH HACKBERRY RED DOGWOOD VIBURNUM RED MAPLES WILLOW STAGHORN SUMAC HAZEL NUT RIVER

Natural Flood Management in context: evaluating and enhancing the impact.

NASA Astrophysics Data System (ADS)

Metcalfe, Peter; Beven, Keith; Hankin, Barry; Lamb, Rob

2016-04-01

The series of flood events in the UK throughout December 2015 have led to calls for a reappraisal of the country's approach to flood management. In parts of Cumbria so-called "1 in 100" year floods have occurred three times in the last ten years, leading to significant infrastructure damage. Hard-engineered defences upgraded to cope with an anticipated 20% increase in peak flows and these 1% AEP events have been overwhelmed. It has become more widely acknowledged that unsympathetic agricultural and upland management practices, mainly since the Second World War, have led to a significant loss of storage in mid and upper catchments and their consequent ability to retain and slow storm run-off. Natural Flood Management (NFM) is a nature-based solution to restoring this storage and flood peak attenuation through a network of small-scale features exploiting natural topography and materials. Combined with other "soft" interventions such as restoring flood plain roughness and tree-planting, NFM offers the attractive prospect of an intervention that can target both the ecological and chemical objectives of the Water Framework Directive and the resilience demanded by the Floods Directive. We developed a simple computerised physical routing model that can account for the presence of in-channel and offline features such as would be found in a NFM scheme. These will add storage to the channel and floodplain and throttle the downstream discharge at storm flows. The model was applied to the heavily-modified channel network of an agricultural catchment in North Yorkshire using the run-off simulated for two storm events that caused flooding downstream in the autumn of 2012. Using up to 60 online features we demonstrated some gains in channel storage and a small impact on the flood hydrograph which would, however, have been insufficient to prevent the downstream floods in either of the storms. Complementary research at JBA has applied their hydrodynamic model JFLOW+ to identify areas of the catchment that will naturally retain storm run-off and quantified the effects of removing this storage on the run-off. It is suggested that enhancing the storage capacity of these areas may be a low impact approach in keeping with the ethos of NFM that has a significant, and quantifiable impact, on storm flows.

Dissolved Nutrient Retention Dynamics in River Networks: A Modeling Investigation of Transient Flow and Scale Effects

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ye, Sheng; Covino, Timothy P.; Sivapalan, Murugesu

In this paper, we use a dynamic network flow model, coupled with a transient storage zone biogeochemical model, to simulate dissolved nutrient removal processes at the channel network scale. We have explored several scenarios in respect of the combination of rainfall variability, and the biological and geomorphic characteristics of the catchment, to understand the dominant controls on removal and delivery of dissolved nutrients (e.g., nitrate). These model-based theoretical analyses suggested that while nutrient removal efficiency is lower during flood events compared to during baseflow periods, flood events contribute significantly to bulk nutrient removal, whereas bulk removal during baseflow periods ismore » less. This is due to the fact that nutrient supply is larger during flood events; this trend is even stronger in large rivers. However, the efficiency of removal during both periods decreases in larger rivers, however, due to (i) increasing flow velocities and thus decreasing residence time, and (ii) increasing flow depth, and thus decreasing nutrient uptake rates. Besides nutrient removal processes can be divided into two parts: in the main channel and in the hyporheic transient storage zone. When assessing their relative contributions the size of the transient storage zone is a dominant control, followed by uptake rates in the main channel and in the transient storage zone. Increasing size of the transient storage zone with downstream distance affects the relative contributions to nutrient removal of the water column and the transient storage zone, which also impacts the way nutrient removal rates scale with increasing size of rivers. Intra-annual hydrologic variability has a significant impact on removal rates at all scales: the more variable the streamflow is, compared to mean discharge, the less nutrient is removed in the channel network. A scale-independent first order uptake coefficient, ke, estimated from model simulations, is highly dependent on the relative size of the transient storage zone and how it changes in the downstream direction, as well as the nature of hydrologic variability.« less

Designing and operating infrastructure for nonstationary flood risk management

NASA Astrophysics Data System (ADS)

Doss-Gollin, J.; Farnham, D. J.; Lall, U.

2017-12-01

Climate exhibits organized low-frequency and regime-like variability at multiple time scales, causing the risk associated with climate extremes such as floods and droughts to vary in time. Despite broad recognition of this nonstationarity, there has been little theoretical development of ideas for the design and operation of infrastructure considering the regime structure of such changes and their potential predictability. We use paleo streamflow reconstructions to illustrate an approach to the design and operation of infrastructure to address nonstationary flood and drought risk. Specifically, we consider the tradeoff between flood control and conservation storage, and develop design and operation principles for allocating these storage volumes considering both a m-year project planning period and a n-year historical sampling record. As n increases, the potential uncertainty in probabilistic estimates of the return periods associated with the T-year extreme event decreases. As the duration m of the future operation period decreases, the uncertainty associated with the occurrence of the T-year event also increases. Finally, given the quasi-periodic nature of the system it may be possible to offer probabilistic predictions of the conditions in the m-year future period, especially if m is small. In the context of such predictions, one can consider that a m-year prediction may have lower bias, but higher variance, than would be associated with using a stationary estimate from the preceding n years. This bias-variance trade-off, and the potential for considering risk management for multiple values of m, provides an interesting system design challenge. We use wavelet-based simulation models in a Bayesian framework to estimate these biases and uncertainty distributions and devise a risk-optimized decision rule for the allocation of flood and conservation storage. The associated theoretical development also provides a methodology for the sizing of storage for new infrastructure under nonstationarity, and an examination of risk adaptation measures which consider both short term and long term options simultaneously.

REAL TIME CONTROL OF SEWERS: US EPA MANUAL

EPA Science Inventory

The problem of sewage spills and local flooding has traditionally been addressed by large scale capital improvement programs that focus on construction alternatives such as sewer separation or construction of storage facilities. The cost of such projects is often high, especiall...

76 FR 17037 - List of Approved Spent Fuel Storage Casks: HI-STORM Flood/Wind Addition

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-28

...-0007] RIN 3150-AI90 List of Approved Spent Fuel Storage Casks: HI-STORM Flood/Wind Addition AGENCY... or the Commission) is proposing to amend its spent fuel storage cask regulations to add the HI-STORM...: June 13, 2011. SAR Submitted by: Holtec International, Inc. SAR Title: Safety Analysis Report on the HI...

Evaluating changes to reservoir rule curves using historical water-level data

USGS Publications Warehouse

Mower, Ethan; Miranda, Leandro E.

2013-01-01

Flood control reservoirs are typically managed through rule curves (i.e. target water levels) which control the storage and release timing of flood waters. Changes to rule curves are often contemplated and requested by various user groups and management agencies with no information available about the actual flood risk of such requests. Methods of estimating flood risk in reservoirs are not easily available to those unfamiliar with hydrological models that track water movement through a river basin. We developed a quantile regression model that uses readily available daily water-level data to estimate risk of spilling. Our model provided a relatively simple process for estimating the maximum applicable water level under a specific flood risk for any day of the year. This water level represents an upper-limit umbrella under which water levels can be operated in a variety of ways. Our model allows the visualization of water-level management under a user-specified flood risk and provides a framework for incorporating the effect of a changing environment on water-level management in reservoirs, but is not designed to replace existing hydrological models. The model can improve communication and collaboration among agencies responsible for managing natural resources dependent on reservoir water levels.

Balancing Flood Risk and Water Supply in California: Policy Search Combining Short-Term Forecast Ensembles and Groundwater Recharge

NASA Astrophysics Data System (ADS)

Herman, J. D.; Steinschneider, S.; Nayak, M. A.

2017-12-01

Short-term weather forecasts are not codified into the operating policies of federal, multi-purpose reservoirs, despite their potential to improve service provision. This is particularly true for facilities that provide flood protection and water supply, since the potential flood damages are often too severe to accept the risk of inaccurate forecasts. Instead, operators must maintain empty storage capacity to mitigate flood risk, even if the system is currently in drought, as occurred in California from 2012-2016. This study investigates the potential for forecast-informed operating rules to improve water supply efficiency while maintaining flood protection, combining state-of-the-art weather hindcasts with a novel tree-based policy optimization framework. We hypothesize that forecasts need only accurately predict the occurrence of a storm, rather than its intensity, to be effective in regions like California where wintertime, synoptic-scale storms dominate the flood regime. We also investigate the potential for downstream groundwater injection to improve the utility of forecasts. These hypotheses are tested in a case study of Folsom Reservoir on the American River. Because available weather hindcasts are relatively short (10-20 years), we propose a new statistical framework to develop synthetic forecasts to assess the risk associated with inaccurate forecasts. The efficiency of operating policies is tested across a range of scenarios that include varying forecast skill and additional groundwater pumping capacity. Results suggest that the combined use of groundwater storage and short-term weather forecasts can substantially improve the tradeoff between water supply and flood control objectives in large, multi-purpose reservoirs in California.

Hydrology

Treesearch

Mark H. Eisenbies; W. Brian Hughes

2000-01-01

Hydrologic processes are the main determinants of the type of wetland located on a site. Precipitation, groundwater, or flooding interact with soil properties and geomorphic setting to yield a complex matrix of conditions that control groundwater flux, water storage and discharge, water chemistry, biotic produvtivity, biodiversity, and biogeochemical cycling....

Assimilation of GRACE Terrestrial Water Storage Observations into a Land Surface Model for the Assessment of Regional Flood Potential

NASA Technical Reports Server (NTRS)

Reager, John T.; Thomas, Alys C.; Sproles, Eric A.; Rodell, Matthew; Beaudoing, Hiroko K.; Li, Bailing; Famiglietti, James S.

2015-01-01

We evaluate performance of the Catchment Land Surface Model (CLSM) under flood conditions after the assimilation of observations of the terrestrial water storage anomaly (TWSA) from NASA's Gravity Recovery and Climate Experiment (GRACE). Assimilation offers three key benefits for the viability of GRACE observations to operational applications: (1) near-real time analysis; (2) a downscaling of GRACE's coarse spatial resolution; and (3) state disaggregation of the vertically-integrated TWSA. We select the 2011 flood event in the Missouri river basin as a case study, and find that assimilation generally made the model wetter in the months preceding flood. We compare model outputs with observations from 14 USGS groundwater wells to assess improvements after assimilation. Finally, we examine disaggregated water storage information to improve the mechanistic understanding of event generation. Validation establishes that assimilation improved the model skill substantially, increasing regional groundwater anomaly correlation from 0.58 to 0.86. For the 2011 flood event in the Missouri river basin, results show that groundwater and snow water equivalent were contributors to pre-event flood potential, providing spatially-distributed early warning information.

Sediment supply versus local hydraulic controls on sediment transport and storage in a river with large sediment loads

USGS Publications Warehouse

Dean, David; Topping, David; Schmidt, John C.; Griffiths, Ronald; Sabol, Thomas

2016-01-01

The Rio Grande in the Big Bend region of Texas, USA, and Chihuahua and Coahuila, Mexico, undergoes rapid geomorphic changes as a result of its large sediment supply and variable hydrology; thus, it is a useful natural laboratory to investigate the relative importance of flow strength and sediment supply in controlling alluvial channel change. We analyzed a suite of sediment transport and geomorphic data to determine the cumulative influence of different flood types on changing channel form. In this study, physically based analyses suggest that channel change in the Rio Grande is controlled by both changes in flow strength and sediment supply over different spatial and temporal scales. Channel narrowing is primarily caused by substantial deposition of sediment supplied to the Rio Grande during tributary-sourced flash floods. Tributary floods have large suspended-sediment concentrations, occur for short durations, and attenuate rapidly downstream in the Rio Grande, depositing much of their sediment in downstream reaches. Long-duration floods on the mainstem have the capacity to enlarge the Rio Grande, and these floods, released from upstream dams, can either erode or deposit sediment in the Rio Grande depending upon the antecedent in-channel sediment supply and the magnitude and duration of the flood. Geomorphic and sediment transport analyses show that the locations and rates of sand erosion and deposition during long-duration floods are most strongly controlled by spatial changes in flow strength, largely through changes in channel slope. However, spatial differences in the in-channel sediment supply regulate sediment evacuation or accumulation over time in long reaches (greater than a kilometer).

Towards a better understanding of flood generation and surface water inundation mechanisms using NASA remote sensing data products

NASA Astrophysics Data System (ADS)

Lucey, J.; Reager, J. T., II; Lopez, S. R.

2017-12-01

Floods annually cause several weather-related fatalities and financial losses. According to NOAA and FEMA, there were 43 deaths and 18 billion dollars paid out in flood insurance policies during 2005. The goal of this work is to improve flood prediction and flood risk assessment by creating a general model of predictability of extreme runoff generation using various NASA products. Using satellite-based flood inundation observations, we can relate surface water formation processes to changes in other hydrological variables, such as precipitation, storage and soil moisture, and understand how runoff generation response to these forcings is modulated by local topography and land cover. Since it is known that a flood event would cause an abnormal increase in surface water, we examine these underlying physical relationships in comparison with the Dartmouth Flood Observatory archive of historic flood events globally. Using ground water storage observations (GRACE), precipitation (TRMM or GPCP), land use (MODIS), elevation (SRTM) and surface inundation levels (SWAMPS), an assessment of geological and climate conditions can be performed for any location around the world. This project utilizes multiple linear regression analysis evaluating the relationship between surface water inundation, total water storage anomalies and precipitation values, grouped by average slope or land use, to determine their statistical relationships and influences on inundation data. This research demonstrates the potential benefits of using global data products for early flood prediction and will improve our understanding of runoff generation processes.

Integrated Urban Flood Analysis considering Optimal Operation of Flood Control Facilities in Urban Drainage Networks

NASA Astrophysics Data System (ADS)

Moon, Y. I.; Kim, M. S.; Choi, J. H.; Yuk, G. M.

2017-12-01

eavy rainfall has become a recent major cause of urban area flooding due to the climate change and urbanization. To prevent property damage along with casualties, a system which can alert and forecast urban flooding must be developed. Optimal performance of reducing flood damage can be expected of urban drainage facilities when operated in smaller rainfall events over extreme ones. Thus, the purpose of this study is to execute: A) flood forecasting system using runoff analysis based on short term rainfall; and B) flood warning system which operates based on the data from pump stations and rainwater storage in urban basins. In result of the analysis, it is shown that urban drainage facilities using short term rainfall forecasting data by radar will be more effective to reduce urban flood damage than using only the inflow data of the facility. Keywords: Heavy Rainfall, Urban Flood, Short-term Rainfall Forecasting, Optimal operating of urban drainage facilities. AcknowledgmentsThis research was supported by a grant (17AWMP-B066744-05) from Advanced Water Management Research Program (AWMP) funded by Ministry of Land, Infrastructure and Transport of Korean government.

Identifying the best locations to install flow control devices in sewer networks to enable in-sewer storage

NASA Astrophysics Data System (ADS)

Leitão, J. P.; Carbajal, J. P.; Rieckermann, J.; Simões, N. E.; Sá Marques, A.; de Sousa, L. M.

2018-01-01

The activation of available in-sewer storage volume has been suggested as a low-cost flood and combined sewer overflow mitigation measure. However, it is currently unknown what the attributes for suitable objective functions to identify the best location for flow control devices are and the impact of those attributes on the results. In this study, we present a novel location model and efficient algorithm to identify the best location(s) to install flow limiters. The model is a screening tool that does not require hydraulic simulations but rather considers steady state instead of simplistic static flow conditions. It also maximises in-sewer storage according to different reward functions that also considers the potential impact of flow control device failure. We demonstrate its usefulness on two real sewer networks, for which an in-sewer storage potential of approximately 2,000 m3 and 500 m3 was estimated with five flow control devices installed.

Effects of experimental water table and temperature manipulations on ecosystem CO2 fluxes in an Alaskan rich fen

USGS Publications Warehouse

Chivers, M.R.; Turetsky, M.R.; Waddington, J.M.; Harden, J.W.; McGuire, A.D.

2009-01-01

Peatlands store 30% of the world's terrestrial soil carbon (C) and those located at northern latitudes are expected to experience rapid climate warming. We monitored growing season carbon dioxide (CO2) fluxes across a factorial design of in situ water table (control, drought, and flooded plots) and soil warming (control vs. warming via open top chambers) treatments for 2 years in a rich fen located just outside the Bonanza Creek Experimental Forest in interior Alaska. The drought (lowered water table position) treatment was a weak sink or small source of atmospheric CO2 compared to the moderate atmospheric CO2 sink at our control. This change in net ecosystem exchange was due to lower gross primary production and light-saturated photosynthesis rather than increased ecosystem respiration. The flooded (raised water table position) treatment was a greater CO2 sink in 2006 due largely to increased early season gross primary production and higher light-saturated photosynthesis. Although flooding did not have substantial effects on rates of ecosystem respiration, this water table treatment had lower maximum respiration rates and a higher temperature sensitivity of ecosystem respiration than the control plot. Surface soil warming increased both ecosystem respiration and gross primary production by approximately 16% compared to control (ambient temperature) plots, with no net effect on net ecosystem exchange. Results from this rich fen manipulation suggest that fast responses to drought will include reduced ecosystem C storage driven by plant stress, whereas inundation will increase ecosystem C storage by stimulating plant growth. ?? 2009 Springer Science+Business Media, LLC.

Magnitude and frequency of flooding on the Myakka River, Southwest Florida

USGS Publications Warehouse

Hammett, K.M.; Turner, J.F.; Murphy, W.R.

1978-01-01

Increasing numbers of urban and agricultural developments are being located on waterfront property in the Myakka River flood plain in southwest Florida. Under natural conditions, a large depression, Tatum Sawgrass, was available as a flood storage area in the upper Myakka River basin. Construction of dikes across the lower part of Tatum Sawgrass has restricted use of the depression for temporary storage of Myakka River flood water overflow, and has resulted in increased flood-peak discharges and flood heights in downstream reaches of the Myakka River. The difference between natural and diked condition flood-peak discharges and flood heights is presented to illustrate the effects of the dikes. Flood-peak discharges, water-surface elevations and flood profiles also are provided for diked conditions. Analytical procedures used to evaluate diking effects are described in detail. The study reach includes Myakka River main stem upstream from U.S. Highway 41, near Myakka Shores in Sarasota County, to State Road 70 near Myakka City in Manatee County (including Tatum Sawgrass and Clay Gully), and Blackburn Canal from Venice By-Way to Myakka River. (Woodard-USGS)

Mapping Flood Protection Benefits from Restored Wetlands at the Urban-Suburban Interface

EPA Science Inventory

Urbanization exacerbates flooding by increasing runoff and decreasing surface water storage. Restoring wetlands can enhance flood protection while providing a suite of co-benefits such as temperature regulation and access to open space. Spatial modeling of the delivery of flood p...

Floods in south-central Oklahoma and north-central Texas, October 1981

USGS Publications Warehouse

Buckner, Harold D.; Kurklin, Joanne K.

1984-01-01

Substantial reductions in peak stages and discharges on the West Fork Trinity River downstream from Eagle Mountain Reservoir were attained as a result of reservoir storage. All floodwater on the Elm Fork Trinity River was contained by reservoir storage thus preventing a potentially devastating flood downstream on the Trinity River. Maximum stages and discharges and/or contents were recorded during and after this major flood at 83 gaging stations, crest-stage stations, reservoir stations, and a miscellaneous site.

Multiple-Purpose Project. Osage River Basin, Big Bull Creek, Kansas. Hillsdale Lake Operation and Maintenance Manual. Appendix V. Embankment Criteria and Performance Report.

DTIC Science & Technology

1984-09-01

and Mississippi Rivers; provide storage for Increasing low - water flows for the Improvement of water supply, abatement of pollution, and improvement...des Cygnes, Osage and Lower Missourl River. Hillsdale Lake will have storage for sediment, low -flow supplementation, water supply, and flood control...will furnish a water supply withdrawal of 32 cubic feet per second on a 2 percent chance dependability and low flow supplementation of 13 cubic feet

The Study on Flood Reduction and Securing Instreamflow by applying Decentralized Rainwater Retention Facilities for Chunggyechun in Seoul of Korea

NASA Astrophysics Data System (ADS)

Park, J. H.; Jun, S. M.; Park, C. G.

2014-12-01

Recently abnormal climate phenomena and urbanization recently causes the changes of the hydrological environment. To restore the hydrological cycle in urban area some fundamental solutions such as decentralized rainwater management system and Low Impact Development (LID) techniques may be choosed. In this study, SWMM 5 was used to analyze the effects of decentralized stormwater retention for preventing the urban flood and securing the instreamflow. The Chunggyechun stream watershed(21.29㎢) which is located in Seoul city(Korea) and fully developed as urban area was selected as the study watershed, and the runoff characteristics of urban stream with various methods of LID techniques (Permeable pavement, small rainwater storage tank, large rainwater storage tank) were analyzed. By the simulation results, the permeability of pavement materials and detention storage at the surface soil layer make high effect to the flood discharge, and the initial rainfall retention at the rainwater storage tank effected to reduce the flood peak. The peak discharge was decreased as 22% for the design precipitation. Moreover the instreamflow was increased as 55% by using adequate LID techniques These kind of data could be used as the basis data for designing urban flood prevention facilities, urban regeneration planning in the view of the integrated watershed management.

Green-blue water in the city: quantification of impact of source control versus end-of-pipe solutions on sewer and river floods.

PubMed

De Vleeschauwer, K; Weustenraad, J; Nolf, C; Wolfs, V; De Meulder, B; Shannon, K; Willems, P

2014-01-01

Urbanization and climate change trends put strong pressures on urban water systems. Temporal variations in rainfall, runoff and water availability increase, and need to be compensated for by innovative adaptation strategies. One of these is stormwater retention and infiltration in open and/or green spaces in the city (blue-green water integration). This study evaluated the efficiency of three adaptation strategies for the city of Turnhout in Belgium, namely source control as a result of blue-green water integration, retention basins located downstream of the stormwater sewers, and end-of-pipe solutions based on river flood control reservoirs. The efficiency of these options is quantified by the reduction in sewer and river flood frequencies and volumes, and sewer overflow volumes. This is done by means of long-term simulations (100-year rainfall simulations) using an integrated conceptual sewer-river model calibrated to full hydrodynamic sewer and river models. Results show that combining open, green zones in the city with stormwater retention and infiltration for only 1% of the total city runoff area would lead to a 30 to 50% reduction in sewer flood volumes for return periods in the range 10-100 years. This is due to the additional surface storage and infiltration and consequent reduction in urban runoff. However, the impact of this source control option on downstream river floods is limited. Stormwater retention downstream of the sewer system gives a strong reduction in peak discharges to the receiving river. However due to the difference in response time between the sewer and river systems, this does not lead to a strong reduction in river flood frequency. The paper shows the importance of improving the interface between urban design and water management, and between sewer and river flood management.

Ensemble Flow Forecasts for Risk Based Reservoir Operations of Lake Mendocino in Mendocino County, California

NASA Astrophysics Data System (ADS)

Delaney, C.; Hartman, R. K.; Mendoza, J.; Evans, K. M.; Evett, S.

2016-12-01

Forecast informed reservoir operations (FIRO) is a methodology that incorporates short to mid-range precipitation or flow forecasts to inform the flood operations of reservoirs. Previous research and modeling for flood control reservoirs has shown that FIRO can reduce flood risk and increase water supply for many reservoirs. The risk-based method of FIRO presents a unique approach that incorporates flow forecasts made by NOAA's California-Nevada River Forecast Center (CNRFC) to model and assess risk of meeting or exceeding identified management targets or thresholds. Forecasted risk is evaluated against set risk tolerances to set reservoir flood releases. A water management model was developed for Lake Mendocino, a 116,500 acre-foot reservoir located near Ukiah, California. Lake Mendocino is a dual use reservoir, which is owned and operated for flood control by the United State Army Corps of Engineers and is operated by the Sonoma County Water Agency for water supply. Due to recent changes in the operations of an upstream hydroelectric facility, this reservoir has been plagued with water supply reliability issues since 2007. FIRO is applied to Lake Mendocino by simulating daily hydrologic conditions from 1985 to 2010 in the Upper Russian River from Lake Mendocino to the City of Healdsburg approximately 50 miles downstream. The risk-based method is simulated using a 15-day, 61 member streamflow hindcast by the CNRFC. Model simulation results of risk-based flood operations demonstrate a 23% increase in average end of water year (September 30) storage levels over current operations. Model results show no increase in occurrence of flood damages for points downstream of Lake Mendocino. This investigation demonstrates that FIRO may be a viable flood control operations approach for Lake Mendocino and warrants further investigation through additional modeling and analysis.

The Need for Modernized Operational Snow Models: A Tale of Two Years

NASA Astrophysics Data System (ADS)

Winstral, A. H.; Marks, D. G.

2014-12-01

The Boise River Basin in southwest Idaho, USA contains three major reservoirs totaling nearly 1,000,000 acre-feet of storage capacity. The primary goals for water managers are water supply and flood protection. In terms of observed SWE at monitoring sites throughout the basin, water years 2012 and 2014 were similar and near normal. In WY 2014 inflows into the BRB reservoir system followed historic patterns and reservoir releases were ideally controlled for management goals. WY2012 however was warmer than average and the winter snowpack had uncharacteristically high melt susceptibility. Subsequent energy fluxes produced late winter inflows much higher than normally encountered. The uncharacteristic flow patterns and inability of traditional operational modeling tools to handle this situation challenged water managers. Through late March and early April 2012 near flood stage flows were pushed through the city of Boise in order to increase storage and prevent more catastrophic flooding. While in this case a greater catastrophe was narrowly averted, the shortcomings of the traditional modeling approaches taken by operational agencies were exposed. "Uncharacteristic" events such as these are becoming more and more frequent as the effects of climate change are realized. The need for modernized methods - ones based on the physical controlling processes rather than historic patterns - is imperative. This presentation outlines the latest developments in the application of a physically-based, high-resolution spatial snow model to aid operational water management decisions.

An assessment of flood mitigation measures - "room for the river

NASA Astrophysics Data System (ADS)

Komma, J.; Blöschl, G.; Habereder, C.

2009-04-01

In this paper we analyse the relative effect of different flood mitigation measures for the example of the Kamp catchment in Austria. The main idea is to decrease flood peaks through (a) retaining water in the landscape and (b) providing additional inundation areas along the main stream (room for the river). To increase the retention of excess rainfall in the landscape we introduced two different measures. One measure is the increase of water storage capacity in the study catchment through the change of land use from agriculture to forest. The second measure is the installation of many small sized retention basins without an outlet (micro ponds). The micro ponds are situated at the hill slopes to intercept surface runoff. In case of the room for the river scenario the additional retention volume is gained due to the installation of retention basins along the Kamp river and its tributary Zwettl. Three flood retention basins with culverts at each river are envisaged. The geometry of the bottom outlets is defined for design discharges in a way to gain the greatest flood peak reduction for large flood events (above a 100 yr flood). The study catchment at the Kamp river with a size of 622 km² is located in north-eastern Austria. For the simulation of the different scenarios (retaining water in the landscape) a well calibrated continuous hydrologic model is available. The hydrological model consists of a spatially distributed soil moisture accounting scheme and a flood routing component. To analyse the effect of the room for the river scenario with retention basins along the river reaches a linked 1D/2D hydrodynamic model (TUFLOW) is used. In the river channels a one dimensional simulation is carried out. The flow conditions in the flood plains are represented by two dimensional model elements. The model domain incorporates 18 km of the Kamp and 12 km of the Zwettl river valley. For the assessment of the land use change scenario the hydrologic model parameters for wooded areas are transferred to areas that are currently not forested. Through higher storage capacities in the wooded areas the scenario of afforestation helps to reduce flood peaks. The micro ponds are represented in the hydrological model by a bucket storage component. It is filled by a fraction of the simulated direct runoff and drains into the groundwater with a constant percolation rate. For the scenarios of flood mitigation with retention basins along the river reaches three locations at the Kamp and three locations at the Zwettl river have been chosen for hypothetical retention basins or polders with bottom outlets. The main difference between the "room for the river" method and the "retaining water in the landscape" methods is the magnitude of the flood event for which the retention is maximised. For the case of retaining water in the landscape (either by land use change or microponds) the storage capacity obtained by these measures is filled at the beginning of the event. For small event magnitudes, the flood peak reduction is hence maximised. In the Kamp catchment, significant reductions in the flood peaks can be obtained when retention basins along the main stream are constructed and the flood plains are inundated. The main advantage of the room for the river methodology is that the polders/retention basins can be designed in a way that there is no retention for small flood discharges which leaves the full storage capacity for larger floods at the time of peak. In contrast, for the retaining water in the landscape measures, the storage is exhausted at an early stage of medium and large events, resulting in very small flood peak reductions.

A Review of Flood-Related Storage and Remobilization of Heavy Metal Pollutants in River Systems.

PubMed

Ciszewski, Dariusz; Grygar, Tomáš Matys

Recently observed rapid climate changes have focused the attention of researchers and river managers on the possible effects of increased flooding frequency on the mobilization and redistribution of historical pollutants within some river systems. This text summarizes regularities in the flood-related transport, channel-to-floodplain transfer, and storage and remobilization of heavy metals, which are the most persistent environmental pollutants in river systems. Metal-dispersal processes are essentially much more variable in alluvia than in soils of non-inundated areas due to the effects of flood-sediment sorting and the mixing of pollutants with grains of different origins in a catchment, resulting in changes of one to two orders of magnitude in metal content over distances of centimetres. Furthermore, metal remobilization can be more intensive in alluvia than in soils as a result of bank erosion, prolonged floodplain inundation associated with reducing conditions alternating with oxygen-driven processes of dry periods and frequent water-table fluctuations, which affect the distribution of metals at low-lying strata. Moreover, metal storage and remobilization are controlled by river channelization, but their influence depends on the period and extent of the engineering works. Generally, artificial structures such as groynes, dams or cut-off channels performed before pollution periods favour the entrapment of polluted sediments, whereas the floodplains of lined river channels that adjust to new, post-channelization hydraulic conditions become a permanent sink for fine polluted sediments, which accumulate solely during overbank flows. Metal mobilization in such floodplains takes place only by slow leaching, and their sediments, which accrete at a moderate rate, are the best archives of the catchment pollution with heavy metals.

Pump Hydro Energy Storage systems (PHES) in groundwater flooded quarries

NASA Astrophysics Data System (ADS)

Poulain, Angélique; de Dreuzy, Jean-Raynald; Goderniaux, Pascal

2018-04-01

Pump storage hydroelectricity is an efficient way to temporarily store energy. This technique requires to store temporarily a large volume of water in an upper reservoir, and to release it through turbines to the lower reservoir, to produce electricity. Recently, the idea of using old flooded quarries as a lower reservoir has been evoked. However, these flooded quarries are generally connected to unconfined aquifers. Consequently, pumping or injecting large volumes of water, within short time intervals, will have an impact on the adjacent aquifers. Conversely, water exchanges between the quarry and the aquifer may also influence the water level fluctuations in the lower reservoir. Using numerical modelling, this study investigates the interactions between generic flooded open pit quarries and adjacent unconfined aquifers, during various pump-storage cyclic stresses. The propagation of sinusoidal stresses in the adjacent porous media and the amplitude of water level fluctuations in the quarry are studied. Homogeneous rock media and the presence of fractures in the vicinity of the quarry are considered. Results show that hydrological quarry - rock interactions must be considered with caution, when implementing pump - storage systems. For rock media characterized by high hydraulic conductivity and porosity values, water volumes exchanges during cycles may affect significantly the amplitude of the water level fluctuations in the quarry, and as a consequence, the instantaneous electricity production. Regarding the impact of the pump - storage cyclic stresses on the surrounding environment, the distance of influence is potentially high under specific conditions, and is enhanced with the occurrence of rock heterogeneities, such as fractures. The impact around the quarry used as a lower reservoir thus appears as an important constraining factor regarding the feasibility of pump - storage systems, to be assessed carefully if groundwater level fluctuations around the quarry are expected to bring up adverse effects. Results highlight opportunities and challenges to be faced, to implement pump - storage hydroelectricity systems in old flooded open pit quarries.

Evaluation of the wind pumped hydropower storage integrated flood mitigation system

NASA Astrophysics Data System (ADS)

Safi, Aishah; Basrawi, Firdaus

2018-04-01

As Wind Pumped Hydropower Storage (WPHS) need high cost to construct, it is important to study their impacts on economic and environmental aspects. Thus, this research aims to evaluate their economic and environmental performances. First, Hybrid Optimization Model for Electric Renewable (HOMER) was used to simulate power generation system with and without the flood reservoir. Next, the total amount of emitted air pollutant was used to evaluate the environmental impacts. It was found the wind-diesel with reservoir storage system (A-III) will have much lower NPC than other systems that do not include reservoir for flood mitigation when the cost of flood losses are included in the total Net Present Cost (NPC). The NPC for system A-III was RM 1.52 million and for diesel standalone system (A-I) is RM 10.8 million when the cost of flood losses are included in the total NPC. Between both energy systems, the amount of pollutants emitted by the A-III system was only 408 kg-CO2/year which is much less than the A-I system which is 99, 754 kg of carbon dioxide per year. To conclude, the WPHS integrated with flood mitigation system seems promising in the aspects of economic and environment.

Lead/acid batteries in systems to improve power quality

NASA Astrophysics Data System (ADS)

Taylor, P.; Butler, P.; Nerbun, W.

Increasing dependence on computer technology is driving needs for extremely high-quality power to prevent loss of information, material, and workers' time that represent billions of dollars annually. This cost has motivated commercial and Federal research and development of energy storage systems that detect and respond to power-quality failures in milliseconds. Electrochemical batteries are among the storage media under investigation for these systems. Battery energy storage systems that employ either flooded lead/acid or valve-regulated lead/acid battery technologies are becoming commercially available to capture a share of this emerging market. Cooperative research and development between the US Department of Energy and private industry have led to installations of lead/acid-based battery energy storage systems to improve power quality at utility and industrial sites and commercial development of fully integrated, modular battery energy storage system products for power quality. One such system by AC Battery Corporation, called the PQ2000, is installed at a test site at Pacific Gas and Electric Company (San Ramon, CA, USA) and at a customer site at Oglethorpe Power Corporation (Tucker, GA, USA). The PQ2000 employs off-the-shelf power electronics in an integrated methodology to control the factors that affect the performance and service life of production-model, low-maintenance, flooded lead/acid batteries. This system, and other members of this first generation of lead/acid-based energy storage systems, will need to compete vigorously for a share of an expanding, yet very aggressive, power quality market.

Optimal Hedging Rule for Reservoir Refill Operation

NASA Astrophysics Data System (ADS)

Wan, W.; Zhao, J.; Lund, J. R.; Zhao, T.; Lei, X.; Wang, H.

2015-12-01

This paper develops an optimal reservoir Refill Hedging Rule (RHR) for combined water supply and flood operation using mathematical analysis. A two-stage model is developed to formulate the trade-off between operations for conservation benefit and flood damage in the reservoir refill season. Based on the probability distribution of the maximum refill water availability at the end of the second stage, three zones are characterized according to the relationship among storage capacity, expected storage buffer (ESB), and maximum safety excess discharge (MSED). The Karush-Kuhn-Tucker conditions of the model show that the optimality of the refill operation involves making the expected marginal loss of conservation benefit from unfilling (i.e., ending storage of refill period less than storage capacity) as nearly equal to the expected marginal flood damage from levee overtopping downstream as possible while maintaining all constraints. This principle follows and combines the hedging rules for water supply and flood management. A RHR curve is drawn analogously to water supply hedging and flood hedging rules, showing the trade-off between the two objectives. The release decision result has a linear relationship with the current water availability, implying the linearity of RHR for a wide range of water conservation functions (linear, concave, or convex). A demonstration case shows the impacts of factors. Larger downstream flood conveyance capacity and empty reservoir capacity allow a smaller current release and more water can be conserved. Economic indicators of conservation benefit and flood damage compete with each other on release, the greater economic importance of flood damage is, the more water should be released in the current stage, and vice versa. Below a critical value, improving forecasts yields less water release, but an opposing effect occurs beyond this critical value. Finally, the Danjiangkou Reservoir case study shows that the RHR together with a rolling horizon decision approach can lead to a gradual dynamic refilling, indicating its potential for practical use.

Full-flow-regime storage-streamflow correlation patterns provide insights into hydrologic functioning over the continental US

NASA Astrophysics Data System (ADS)

Fang, Kuai; Shen, Chaopeng

2017-09-01

Interannual changes in low, median, and high regimes of streamflow have important implications for flood control, irrigation, and ecologic and human health. The Gravity Recovery and Climate Experiment (GRACE) satellites record global terrestrial water storage anomalies (TWSA), providing an opportunity to observe, interpret, and potentially utilize the complex relationships between storage and full-flow-regime streamflow. Here we show that utilizable storage-streamflow correlations exist throughout vastly different climates in the continental US (CONUS) across low- to high-flow regimes. A panoramic framework, the storage-streamflow correlation spectrum (SSCS), is proposed to examine macroscopic gradients in these relationships. SSCS helps form, corroborate or reject hypotheses about basin hydrologic behaviors. SSCS patterns vary greatly over CONUS with climate, land surface, and geologic conditions. Data mining analysis suggests that for catchments with hydrologic settings that favor storage over runoff, e.g., a large fraction of precipitation as snow, thick and highly-permeable permeable soil, SSCS values tend to be high. Based on our results, we form the hypotheses that groundwater flow dominates streamflows in Southeastern CONUS and Great Plains, while thin soils in a belt along the Appalachian Plateau impose alimit on water storage. SSCS also suggests shallow water table caused by high-bulk density soil and flat terrain induces rapid runoff in several regions. Our results highlight the importance of subsurface properties and groundwater flow in capturing flood and drought. We propose that SSCS can be used as a fundamental hydrologic signature to constrain models and to provide insights thatlead usto better understand hydrologic functioning.

Bank storage buffers rivers from saline regional groundwater: an example from the Avon River Australia

NASA Astrophysics Data System (ADS)

Gilfedder, Benjamin; Hofmann, Harald; Cartwrighta, Ian

2014-05-01

Groundwater-surface water interactions are often conceptually and numerically modeled as a two component system: a groundwater system connected to a stream, river or lake. However, transient storage zones such as hyporheic exchange, bank storage, parafluvial flow and flood plain storage complicate the two component model by delaying the release of flood water from the catchment. Bank storage occurs when high river levels associated with flood water reverses the hydraulic gradient between surface water and groundwater. River water flows into the riparian zone, where it is stored until the flood water recede. The water held in the banks then drains back into the river over time scales ranging from days to months as the hydraulic gradient returns to pre-flood levels. If the frequency and amplitude of flood events is high enough, water held in bank storage can potentially perpetually remain between the regional groundwater system and the river. In this work we focus on the role of bank storage in buffering river salinity levels against saline regional groundwater on lowland sections of the Avon River, Victoria, Australia. We hypothesize that the frequency and magnitude of floods will strongly influence the salinity of the stream water as banks fill and drain. A bore transect (5 bores) was installed perpendicular to the river and were instrumented with head and electrical conductivity loggers measuring for two years. We also installed a continuous 222Rn system in one bore. This data was augmented with long-term monthly EC from the river. During high rainfall events very fresh flood waters from the headwaters infiltrated into the gravel river banks leading to a dilution in EC and 222Rn in the bores. Following the events the fresh water drained back into the river as head gradients reversed. However the bank water salinities remained ~10x lower than regional groundwater levels during most of the time series, and only slightly above river water. During 2012 SE Australia experienced a prolonged summer drought. A significant increase in EC was observed in the bores towards the end of the summer, which suggest that the lack of bank recharge from the river resulted in draining of the banks and connection between the regional groundwater and the river. The long-term river salinity dataset showed that when flow events are infrequent and of low magnitude (i.e. drought conditions), salinities increase significantly. Similarly this is thought to be due to draining of the banks and connection with the regional groundwater system. Thus an increase in extended dry periods is expected to result in higher salinities in Australian waterways as the climate changes.

Integrating a Typhoon Event Database with an Optimal Flood Operation Model on the Real-Time Flood Control of the Tseng-Wen Reservoir

NASA Astrophysics Data System (ADS)

Chen, Y. W.; Chang, L. C.

2012-04-01

Typhoons which normally bring a great amount of precipitation are the primary natural hazard in Taiwan during flooding season. Because the plentiful rainfall quantities brought by typhoons are normally stored for the usage of the next draught period, the determination of release strategies for flood operation of reservoirs which is required to simultaneously consider not only the impact of reservoir safety and the flooding damage in plain area but also for the water resource stored in the reservoir after typhoon becomes important. This study proposes a two-steps study process. First, this study develop an optimal flood operation model (OFOM) for the planning of flood control and also applies the OFOM on Tseng-wun reservoir and the downstream plain related to the reservoir. Second, integrating a typhoon event database with the OFOM mentioned above makes the proposed planning model have ability to deal with a real-time flood control problem and names as real-time flood operation model (RTFOM). Three conditions are considered in the proposed models, OFOM and RTFOM, include the safety of the reservoir itself, the reservoir storage after typhoons and the impact of flooding in the plain area. Besides, the flood operation guideline announced by government is also considered in the proposed models. The these conditions and the guideline can be formed as an optimization problem which is solved by the genetic algorithm (GA) in this study. Furthermore, a distributed runoff model, kinematic-wave geomorphic instantaneous unit hydrograph (KW-GIUH), and a river flow simulation model, HEC-RAS, are used to simulate the river water level of Tseng-wun basin in the plain area and the simulated level is shown as an index of the impact of flooding. Because the simulated levels are required to re-calculate iteratively in the optimization model, applying a recursive artificial neural network (recursive ANN) instead of the HEC-RAS model can significantly reduce the computational burden of the entire optimization problem. This study applies the developed methodology to Tseng-wun Reservoir. Forty typhoon events are collected as the historical database and six typhoon events are used to verify the proposed model. These typhoons include Typhoon Sepat and Typhoon Korsa in 2007 and Typhoon Kalmaegi, Typhoon Fung-Wong, Typhoon Sinlaku and Typhoon Jangmi in 2008. The results show that the proposed model can reduce the flood duration at the downstream area. For example, the real-time flood control model can reduce the flood duration by four and three hours for Typhoon Korsa and Typhoon Sinlaku respectively. This results indicate that the developed model can be a very useful tool for real-time flood control operation of reservoirs.

Origin of the Colorado River experimental flood in Grand Canyon

USGS Publications Warehouse

Andrews, E.D.; Pizzi, L.A.

2000-01-01

The Colorado River is one of the most highly regulated and extensively utilized rivers in the world. Total reservoir storage is approximately four times the mean annual runoff of ~17 x 109 m3 year -1. Reservoir storage and regulation have decreased annual peak discharges and hydroelectric power generation has increased daily flow variability. In recent years, the incidental impacts of this development have become apparent especially along the Colorado River through Grand Canyon National Park downstream from Glen Canyon Dam and caused widespread concern. Since the completion of Glen Canyon Dam, the number and size of sand bars, which are used by recreational river runners and form the habitat for native fishes, have decreased substantially. Following an extensive hydrological and geomorphic investigation, an experimental flood release from the Glen Canyon Dam was proposed to determine whether sand bars would be rebuilt by a relatively brief period of flow substantially greater than the normal operating regime. This proposed release, however, was constrained by the Law of the River, the body of law developed over 70 years to control and distribute Colorado River water, the needs of hydropower users and those dependent upon hydropower revenues, and the physical constraints of the dam itself. A compromise was reached following often difficult negotiations and an experimental flood to rebuild sand bars was released in 1996. This flood, and the process by which it came about, gives hope to resolving the difficult and pervasive problem of allocation of water resources among competing interests.The Colorado River is one of the most highly regulated and extensively utilized rivers in the world. Total reservoir storage is approximately four times the mean annual runoff of approximately 17??109 m3 year-1. Reservoir storage and regulation have decreased annual peak discharges and hydroelectric power generation has increased daily flow variability. In recent years, the incidental impacts of this development have become apparent especially along the Colorado River through Grand Canyon National Park downstream from Glen Canyon Dam and caused widespread concern. Since the completion of Glen Canyon Dam, the number and size of sand bars, which are used by recreational river runners and form the habitat for native fishes, have decreased substantially. Following an extensive hydrological and geomorphic investigation, an experimental flood release from the Glen Canyon Dam was proposed to determine whether sand bars would be rebuilt by a relatively brief period of flow substantially greater than the normal operating regime. This proposed release, however, was constrained by the Law of the River, the body of law developed over 70 years to control and distribute Colorado River water, the needs of hydropower users and those dependent upon hydropower revenues, and the physical constraints of the dam itself. A compromise was reached following often difficult negotiations and an experimental flood to rebuild sand bars was released in 1996. This flood, and the process by which it came about, gives hope to resolving the difficult and pervasive problem of allocation of water resources among competing interests.

Dynamics of flood water infiltration and ground water recharge in hyperarid desert.

PubMed

Dahan, Ofer; Tatarsky, Boaz; Enzel, Yehouda; Kulls, Christoph; Seely, Mary; Benito, Gererdo

2008-01-01

A study on flood water infiltration and ground water recharge of a shallow alluvial aquifer was conducted in the hyperarid section of the Kuiseb River, Namibia. The study site was selected to represent a typical desert ephemeral river. An instrumental setup allowed, for the first time, continuous monitoring of infiltration during a flood event through the channel bed and the entire vadose zone. The monitoring system included flexible time domain reflectometry probes that were designed to measure the temporal variation in vadose zone water content and instruments to concurrently measure the levels of flood and ground water. A sequence of five individual floods was monitored during the rainy season in early summer 2006. These newly generated data served to elucidate the dynamics of flood water infiltration. Each flood initiated an infiltration event which was expressed in wetting of the vadose zone followed by a measurable rise in the water table. The data enabled a direct calculation of the infiltration fluxes by various independent methods. The floods varied in their stages, peaks, and initial water contents. However, all floods produced very similar flux rates, suggesting that the recharge rates are less affected by the flood stages but rather controlled by flow duration and available aquifer storage under it. Large floods flood the stream channel terraces and promote the larger transmission losses. These, however, make only a negligible contribution to the recharge of the ground water. It is the flood duration within the active streambed, which may increase with flood magnitude that is important to the recharge process.

Increased Extreme Hydrological Events and Decreased Water Supply Availability for the Southwestern United States Projected by Mid-Century

NASA Astrophysics Data System (ADS)

Pagan, B. R.; Ashfaq, M.; Rastogi, D.; Naz, B. S.; Kao, S. C.; Mei, R.; Kendall, D. R.; Pal, J. S.

2014-12-01

Semi-arid Southern California relies primarily on imported water originating mostly from snowpack in basins outside of the region including the San-Joaquin River, Tulare Lake, Sacramento River, Owens Valley, Mono Lake, and Colorado River basins. This study provides an integrated ensemble approach to assessing climate change impacts on the hydrologic cycle and hydrologic extremes for all water supplies to Southern California. Output from 10 global climate models is used to force a regional climate model and hydrological model resulting in high-resolution 4.17-km output for the region. Greenhouse gas concentrations are prescribed according to historical values for the present-day (1965-2005) and the IPCC Representative Concentration Pathway 8.5 for the near to mid term future (2010-2050). On the annual timescale, temperature, precipitation and evaporation increase throughout the majority of the study area. With increased temperatures, precipitation is less likely to fall as snow, decreasing snowpack and natural storage and shifting peak flows to earlier in the year. Daily annual maximum runoff and precipitation events are projected to significantly increase in intensity and frequency by mid-century. The 50-year event, for example, becomes approximately five times more likely in the Colorado River basin and twice as likely in the other basins. In densely populated coastal Southern Californian cities, extreme flood events become three to five times as likely substantially increasing the risk of overburdening flood control systems and potential widespread flooding. The escalating likelihood of the combined effects of runoff occurring earlier in the year and in significantly higher amounts poses a substantial flood control risk requiring adaptation measures such as water release from reservoirs. Significant snowpack reductions and increased flood risk will likely necessitate additional multiyear storage solutions for urban and agricultural regions in the Southwestern US.

Increased Extreme Hydrological Events and Decreased Water Supply Availability for the Southwestern United States Projected by Mid-Century

NASA Astrophysics Data System (ADS)

Pagan, B. R.; Ashfaq, M.; Rastogi, D.; Naz, B. S.; Kao, S. C.; Mei, R.; Kendall, D. R.; Pal, J. S.

2015-12-01

Semi-arid Southern California relies primarily on imported water originating mostly from snowpack in basins outside of the region including the San-Joaquin River, Tulare Lake, Sacramento River, Owens Valley, Mono Lake, and Colorado River basins. This study provides an integrated ensemble approach to assessing climate change impacts on the hydrologic cycle and hydrologic extremes for all water supplies to Southern California. Output from 10 global climate models is used to force a regional climate model and hydrological model resulting in high-resolution 4.17-km output for the region. Greenhouse gas concentrations are prescribed according to historical values for the present-day (1965-2005) and the IPCC Representative Concentration Pathway 8.5 for the near to mid term future (2010-2050). On the annual timescale, temperature, precipitation and evaporation increase throughout the majority of the study area. With increased temperatures, precipitation is less likely to fall as snow, decreasing snowpack and natural storage and shifting peak flows to earlier in the year. Daily annual maximum runoff and precipitation events are projected to significantly increase in intensity and frequency by mid-century. The 50-year event, for example, becomes approximately five times more likely in the Colorado River basin and twice as likely in the other basins. In densely populated coastal Southern Californian cities, extreme flood events become three to five times as likely substantially increasing the risk of overburdening flood control systems and potential widespread flooding. The escalating likelihood of the combined effects of runoff occurring earlier in the year and in significantly higher amounts poses a substantial flood control risk requiring adaptation measures such as water release from reservoirs. Significant snowpack reductions and increased flood risk will likely necessitate additional multiyear storage solutions for urban and agricultural regions in the Southwestern US.

Feedbacks between Reservoir Operation and Floodplain Development

NASA Astrophysics Data System (ADS)

Wallington, K.; Cai, X.

2017-12-01

The increased connectedness of socioeconomic and natural systems warrants the study of them jointly as Coupled Natural-Human Systems (CNHS) (Liu et al., 2007). One such CNHS given significant attention in recent years has been the coupled sociological-hydrological system of floodplains. Di Baldassarre et al. (2015) developed a model coupling floodplain development and levee heightening, a flood control measure, which demonstrated the "levee effect" and "adaptation effect" seen in observations. Here, we adapt the concepts discussed by Di Baldassarre et al. (2015) and apply them to floodplains in which the primary flood control measure is reservoir storage, rather than levee construction, to study the role of feedbacks between reservoir operation and floodplain development. Specifically, we investigate the feedback between floodplain development and optimal management of trade-offs between flood water conservation and flood control. By coupling a socio-economic model based on that of Di Baldassarre et al. (2015) with a reservoir optimization model based on that discussed in Ding et al. (2017), we show that reservoir operation rules can co-evolve with floodplain development. Furthermore, we intend to demonstrate that the model results are consistent with real-world data for reservoir operating curves and floodplain development. This model will help explain why some reservoirs are currently operated for purposes which they were not originally intended and thus inform reservoir design and construction.

Residence times and mixing of water in river banks: implications for recharge and groundwater-surface water exchange

NASA Astrophysics Data System (ADS)

Unland, N. P.; Cartwright, I.; Cendón, D. I.; Chisari, R.

2014-12-01

Bank exchange processes within 50 m of the Tambo River, southeast Australia, have been investigated through the combined use of 3H and 14C. Groundwater residence times increase towards the Tambo River, which suggests the absence of significant bank storage. Major ion concentrations and δ2H and δ18O values of bank water also indicate that bank infiltration does not significantly impact groundwater chemistry under baseflow and post-flood conditions, suggesting that the gaining nature of the river may be driving the return of bank storage water back into the Tambo River within days of peak flood conditions. The covariance between 3H and 14C indicates the leakage and mixing between old (~17 200 years) groundwater from a semi-confined aquifer and younger groundwater (<100 years) near the river, where confining layers are less prevalent. It is likely that the upward infiltration of deeper groundwater from the semi-confined aquifer during flooding limits bank infiltration. Furthermore, the more saline deeper groundwater likely controls the geochemistry of water in the river bank, minimising the chemical impact that bank infiltration has in this setting. These processes, coupled with the strongly gaining nature of the Tambo River are likely to be the factors reducing the chemical impact of bank storage in this setting. This study illustrates the complex nature of river groundwater interactions and the potential downfall in assuming simple or idealised conditions when conducting hydrogeological studies.

24 CFR 55.2 - Terminology.

Code of Federal Regulations, 2014 CFR

2014-04-01

... or inoperative during flood and storm events (e.g., data storage centers, generating plants...” (§ 55.2(b)(5)). When FEMA provides interim flood hazard data, such as Advisory Base Flood Elevations... data may be used as “best available information” in accordance with Executive Order 11988. However, a...

The future role of dams in the United States of America

NASA Astrophysics Data System (ADS)

Ho, Michelle; Lall, Upmanu; Allaire, Maura; Devineni, Naresh; Kwon, Hyun Han; Pal, Indrani; Raff, David; Wegner, David

2017-02-01

xml:id="wrcr22481-sec-1001" numbered="no">Storage and controlled distribution of water have been key elements of a human strategy to overcome the space and time variability of water, which have been marked by catastrophic droughts and floods throughout the course of civilization. In the United States, the peak of dam building occurred in the mid-20th century with knowledge limited to the scientific understanding and hydrologic records of the time. Ecological impacts were considered differently than current legislative and regulatory controls would potentially dictate. Additionally, future costs such as maintenance or removal beyond the economic design life were not fully considered. The converging risks associated with aging water storage infrastructure and uncertainty in climate in addition to the continuing need for water storage, flood protection, and hydropower result in a pressing need to address the state of dam infrastructure across the nation. Decisions regarding the future of dams in the United States may, in turn, influence regional water futures through groundwater outcomes, economic productivity, migration, and urban growth. We advocate for a comprehensive national water assessment and a formal analysis of the role dams play in our water future. We emphasize the urgent need for environmentally and economically sound strategies to integrate surface and groundwater storage infrastructure in local, regional, and national water planning considerations. A research agenda is proposed to assess dam failure impacts and the design, operation, and need for dams considering both paleo and future climate, utilization of groundwater resources, and the changing societal values toward the environment.

Streamflow and sediment data collected to determine the effects of a controlled flood in March and April 1996 on the Colorado River between Lees Ferry and Diamond Creek, Arizona

USGS Publications Warehouse

Konieczki, Alice D.; Graf, Julia B.; Carpenter, Michael C.

1997-01-01

An 8-day period of planned release of water at 1,275 cubic meters per second from Glen Canyon Dam in March and April 1996 provided an opportunity to collect data on river stage, streamflow, water chemistry, and sediment transport at discharges above powerplant releases. The U.S. Geological Survey collected data at five streamflow-gaging stations on the mainstem of the Colorado River and four on tributaries during the controlled flood. River-stage data were collected at an additional 29 locations, and suspended-sediment data were collected at 4 of the 5 mainstem streamflow-gaging stations. In addition, measurements of reach-average flow velocity were made using a dye tracer, and water-surface slope was measured in reaches adjacent to three of the streamflow-gaging stations. Sand-storage changes caused by the controlled flood were documented by measuring bed elevation of the channel at cross sections before and after the controlled releases at the network of 120 monumented locations. This report presents selected data in tabular and graphical form. The data presented in the report are available in electronic form.

Design and Flood Control Assessment of 5MWp Fishing and Photovoltaic Power Project in Xinghua City

NASA Astrophysics Data System (ADS)

Guo, Liuchao; Hu, Xiaodong; Su, Yuyan; Wu, Peipei; Weng, Songgan

2017-12-01

In order to reduce coal consumption in Jiangsu Province and develop new energy sources, considering on the distribution of geology, solar energy resources, traffic and grid connection in Xinghua City, the aim is to determine the configuration of photovoltaic modules and photovoltaic array tracking mode, design photovoltaic array and layout scheme. But the project is a wading project, it is built in Dong Tan Lake polder I115, it needs scientific and reasonable evaluation to the effect of Dong Tan Lake’s flood storage and discharge. The results can provide guidance for similar engineering’s design.

Impact of Sedimentation hazard at Jor Reservoir, Batang Padang Hydroelectric Scheme in Malaysia

NASA Astrophysics Data System (ADS)

Luis, Jansen; Mohd Sidek, Lariyah; Jajarmizadeh, Milad

2016-03-01

Sedimentation in reservoir can be treated as a hazard because it affects the overall safety of the dam. It is a growing concern for reservoir operators throughout the world as it impacts the operability of the hydropower plant and its function as flood control. The objective of the study is to carry out reservoir bathymetric survey to determine the storage volume available at Jor reservoir. The paper intends to discuss the results of two successive surveys carried out in year 2007 and 2010 and comparison with historical data in1968 owing to analyse of sedimentation trend. The result showed that the total storage loss is approximately 43% with an estimated deposited sediment volume of 1.4 million m3 in year 2010. The sedimentation rate is estimated at 3.3% for the years surveyed which is greater than the world average of 0.93%. The findings from the survey are used to develop a revised elevation-storage curve which could be used by the operator and engineers to carry out future power generation planning and flood study predictions. The findings are also expected to be used to determine the optimum method for sediment management and hydro-mechanical protection.

Floods in mountain environments: A synthesis

NASA Astrophysics Data System (ADS)

Stoffel, Markus; Wyżga, Bartłomiej; Marston, Richard A.

2016-11-01

Floods are a crucial agent of geomorphic change in the channels and valley floors of mountains watercourses. At the same time, they can be highly damaging to property, infrastructure, and life. Because of their high energy, mountain watercourses are highly vulnerable to environmental changes affecting their catchments and channels. Many factors have modified and frequently still tend to modify the environmental conditions in mountain areas, with impacts on geomorphic processes and the frequency, magnitude, and timing of floods in mountain watercourses. The ongoing climate changes vary between regions but may affect floods in mountain areas in many ways. In many mountain regions of Europe, widespread afforestation took place over the twentieth century, considerably increasing the amounts of large wood delivered to the channels and the likelihood of jamming bridges. At the same time, deforestation continues in other mountain areas, accelerating runoff and amplifying the magnitude and frequency of floods in foreland areas. In many countries, in-channel gravel mining has been a common practice during recent decades; the resultant deficit of bed material in the affected channels may suddenly manifest during flood events, resulting in the failure of scoured bridges or catastrophic channel widening. During the past century many rivers in mountain and foreland areas incised deeply; the resultant loss of floodplain water storage has decreased attenuation of flood waves, hence increasing flood hazard to downstream river reaches. On the other hand, a large amount of recent river restoration activities worldwide may provide examples of beneficial changes to flood risk, attained as a result of increased channel storage or reestablished floodplain water storage. Relations between geomorphic processes and floods operate in both directions, which means that changes in flood probability or the character of floods (e.g., increased wood load) may significantly modify the morphology of mountain rivers, but morphological changes of rivers can also affect hydrological properties of floods and the associated risk for societies. This paper provides a review of research in the field of floods in mountain environments and puts the papers of this special issue dedicated to the same topic into context. It also provides insight into innovative studies, methods, or emerging aspects of the relations between environmental changes, geomorphic processes, and the occurrence of floods in mountain rivers.

Volumes of recent floods and potential for storage in upland watershed areas of Iowa

USGS Publications Warehouse

Buchmiller, Robert C.; Eash, David A.; Harvey, Craig A.

2000-01-01

During the autumn of 1997, the U.S. Geological Survey (USGS), in cooperation with the U.S. Environmental Protection Agency, began a study to determine the volume of water associated with recent flood events in parts of the Midwestern United States and a preliminary evaluation of the potential upland areas for storage of flood-waters in selected watersheds. This analysis, although preliminary, may be useful in determining the feasibility of conducting additional, more detailed studies into the role of upland areas in a watershed management strategy. The methods and results of this preliminary hydrologic study are presented in this report.

Model Predictive Control application for real time operation of controlled structures for the Water Authority Noorderzijlvest, The Netherlands

NASA Astrophysics Data System (ADS)

van Heeringen, Klaas-Jan; Gooijer, Jan; Knot, Floris; Talsma, Jan

2015-04-01

In the Netherlands, flood protection has always been a key issue to protect settlements against storm surges and riverine floods. Whereas flood protection traditionally focused on structural measures, nowadays the availability of meteorological and hydrological forecasts enable the application of more advanced real-time control techniques for operating the existing hydraulic infrastructure in an anticipatory and more efficient way. Model Predictive Control (MPC) is a powerful technique to derive optimal control variables with the help of model based predictions evaluated against a control objective. In a project for the regional water authority Noorderzijlvest in the north of the Netherlands, it has been shown that MPC can increase the safety level of the system during flood events by an anticipatory pre-release of water. Furthermore, energy costs of pumps can be reduced by making tactical use of the water storage and shifting pump activities during normal operating conditions to off-peak hours. In this way cheap energy is used in combination of gravity flow through gates during low tide periods. MPC has now been implemented for daily operational use of the whole water system of the water authority Noorderzijlvest. The system developed to a real time decision support system which not only supports the daily operation but is able to directly implement the optimal control settings at the structures. We explain how we set-up and calibrated a prediction model (RTC-Tools) that is accurate and fast enough for optimization purposes, and how we integrated it in the operational flood early warning system (Delft-FEWS). Beside the prediction model, the weights and the factors of the objective function are an important element of MPC, since they shape the control objective. We developed special features in Delft-FEWS to allow the operators to adjust the objective function in order to meet changing requirements and to evaluate different control strategies.

Buffalo Metropolitan Area, New York Water Resources Management. Interim Report on Feasibility of Flood Management. Appendices.

DTIC Science & Technology

1983-07-01

storage areas were taken into account during the flood routings. AI.36 The computer program REVPULS, developed for this report, reverse Modified Puls...routed the hydrograph at Batavia through the storage upstream of the LVRR embankment. Subtracting this reverse -routed hydrograph from the combined...segments to form a more accurate reconstitution. The hydrographs upstream of Batavia were derived by reverse -routing and prorating by drainage area. Table

Submergible barge retrievable storage and permanent disposal system for radioactive waste

DOEpatents

Goldsberry, Fred L.; Cawley, William E.

1981-01-01

A submergible barge and process for submerging and storing radioactive waste material along a seabed. A submergible barge receives individual packages of radwaste within segregated cells. The cells are formed integrally within the barge, preferably surrounded by reinforced concrete. The cells are individually sealed by a concrete decking and by concrete hatch covers. Seawater may be vented into the cells for cooling, through an integral vent arrangement. The vent ducts may be attached to pumps when the barge is bouyant. The ducts are also arranged to promote passive ventilation of the cells when the barge is submerged. Packages of the radwaste are loaded into individual cells within the barge. The cells are then sealed and the barge is towed to the designated disposal-storage site. There, the individual cells are flooded and the barge will begin descent controlled by a powered submarine control device to the seabed storage site. The submerged barge will rest on the seabed permanently or until recovered by a submarine control device.

Adaptation to flooding during emergence and seedling growth in rice and weeds, and implications for crop establishment.

PubMed

Ismail, Abdelbagi M; Johnson, David E; Ella, Evangelina S; Vergara, Georgina V; Baltazar, Aurora M

2012-01-01

Direct seeding of rice is being adopted in rainfed and irrigated lowland ecosystems because it reduces labour costs in addition to other benefits. However, early flooding due to uneven fields or rainfall slows down seed germination and hinders crop establishment. Conversely, early flooding helps suppress weeds and reduces the costs of manual weeding and/or dependence on herbicides; however, numerous weed species are adapted to lowlands and present challenges for the use of flooding to control weeds. Advancing knowledge on the mechanisms of tolerance of flooding during germination and early growth in rice and weeds could facilitate the development of improved rice varieties and effective weed management practices for direct-seeded rice. Rice genotypes with a greater ability to germinate and establish in flooded soils were identified, providing opportunities to develop varieties suitable for direct seeding in flooded soils. Tolerance of flooding in these genotypes was mostly attributed to traits associated with better ability to mobilize stored carbohydrates and anaerobic metabolism. Limited studies were undertaken in weeds associated with lowland rice systems. Remaining studies compared rice and weeds and related weed species such as Echinochloa crus-galli and E. colona or compared ecotypes of the same species of Cyperus rotundus adapted to either aerobic or flooded soils. Tolerant weeds and rice genotypes mostly developed similar adaptive traits that allow them to establish in flooded fields, including the ability to germinate and elongate faster under hypoxia, mobilize stored starch reserves and generate energy through fermentation pathways. Remarkably, some weeds developed additional traits such as larger storage tubers that enlarge further in deeper flooded soils (C. rotundus). Unravelling the mechanisms involved in adaptation to flooding will help design management options that will allow tolerant rice genotypes to adequately establish in flooded soils while simultaneously suppressing weeds.

Derivation of Optimal Operating Rules for Large-scale Reservoir Systems Considering Multiple Trade-off

NASA Astrophysics Data System (ADS)

Zhang, J.; Lei, X.; Liu, P.; Wang, H.; Li, Z.

2017-12-01

Flood control operation of multi-reservoir systems such as parallel reservoirs and hybrid reservoirs often suffer from complex interactions and trade-off among tributaries and the mainstream. The optimization of such systems is computationally intensive due to nonlinear storage curves, numerous constraints and complex hydraulic connections. This paper aims to derive the optimal flood control operating rules based on the trade-off among tributaries and the mainstream using a new algorithm known as weighted non-dominated sorting genetic algorithm II (WNSGA II). WNSGA II could locate the Pareto frontier in non-dominated region efficiently due to the directed searching by weighted crowding distance, and the results are compared with those of conventional operating rules (COR) and single objective genetic algorithm (GA). Xijiang river basin in China is selected as a case study, with eight reservoirs and five flood control sections within four tributaries and the mainstream. Furthermore, the effects of inflow uncertainty have been assessed. Results indicate that: (1) WNSGA II could locate the non-dominated solutions faster and provide better Pareto frontier than the traditional non-dominated sorting genetic algorithm II (NSGA II) due to the weighted crowding distance; (2) WNSGA II outperforms COR and GA on flood control in the whole basin; (3) The multi-objective operating rules from WNSGA II deal with the inflow uncertainties better than COR. Therefore, the WNSGA II can be used to derive stable operating rules for large-scale reservoir systems effectively and efficiently.

Water in urban planning, Salt Creek Basin, Illinois water management as related to alternative land-use practices

USGS Publications Warehouse

Spieker, Andrew Maute

1970-01-01

Water management can be an integral part of urban comprehensive planning in a large metropolitan area. Water both imposes constraints on land use and offers opportunities for coordinated land and water management. Salt Creek basin in Cook and Du Page Counties of the Chicago metropolitan area is typical of rapidly developing suburban areas and has been selected to illustrate some of these constraints and opportunities and to suggest the effects of alternative solutions. The present study concentrates on the related problems of ground-water recharge, water quality, management of flood plains, and flood-control measures. Salt Creek basin has a drainage area of 150 square miles. It is in flat to. gently rolling terrain, underlain by glacial drift as much as 200 feet thick which covers a dolomite aquifer. In 1964, the population of the basin was about 400,000, and 40 percent of the land was in urban development. The population is expected to number 550,000 to 650,000 by 1990, and most of the land will be taken by urban development. Salt Creek is a sluggish stream, typical of small drainage channels in the headwaters area of northeastern Illinois. Low flows of 15 to 25 cubic feet per second in the lower part of the basin consist largely of sewage effluent. Nearly all the public water supplies in the basin depend on ground water. Of the total pumpage of 27.5 million gallons per day, 17.5 million gallons per day is pumped from the deep (Cambrian-Ordovician) aquifers and 10 million gallons per day is pumped from the shallow (Silurian dolomite and glacial drift) aquifers. The potential yield of the shallow aquifers, particularly glacial drift in the northern part of the basin, far exceeds present use. The largest concentration of pumpage from the shallow ,aquifers is in the Hinsdale-La Grange area. Salt Creek serves as an important source of recharge to these supplies, particularly just east of Hinsdale. The entire reach of Salt Creek south and east of Elmhurst can be regarded as an area of potential recharge to the shallow aquifers. Preservation of the effectiveness of these potential recharge areas should be considered in land-use planning. Salt Creek is polluted in times of both low and high flow. Most communities in the basin in Du Page County discharge their treated sewage into the creek, whereas those in Cook County transfer their sewage to plants of the Metropolitan Sanitary District outside the basin. During periods of high runoff, combined storm runoff and overflow from sanitary sewers enter the creek. Such polluted water detracts from the stream's esthetic and recreational potential and poses a threat to ground-water supplies owing to induced recharge of polluted water to shallow aquifers. Alternative approaches .to the pollution problem include improvement of the degree of sewage treatment, detention and treatment of storm runoff, dilution of sewage through flow augmentation, or transfer of sewage from the basin to a central treatment plant. To result in an enhanced environment, the streambed would have to be cleansed of accumulated sludge deposits. The overbank flooding in Salt Creek basin every 2 to 3 years presents problems because of encroachments and developments on the flood plains. Flood plains in an urban area can be managed by identifying them, by recognizing that either their natural storage capacity or equivalent artificial capacity is needed to accommodate floods, and by planning land use accordingly. Examples of effective floodplain management include (1) preservation of greenbelts or regional parks along stream courses, (2) use of flood plains for recreation, parking lots. or other low-intensity uses, (3) use of flood-proofed commercial buildings, and (4) provision for compensatory storage to replace natural storage capacity. Results of poor flood-plain management include uncontrolled residential development and encroachment by fill into natural storage areas where no compensatory storage has been

Effects of a flood pulse on exchange flows along a sinuous stream

NASA Astrophysics Data System (ADS)

Käser, D.; Brunner, P.; Renard, P.; Perrochet, P.; Schirmer, M.; Hunkeler, D.

2012-04-01

Flood pulses are important events for river ecosystems: they create hydrological interactions at the terrestrial/aquatic interface that fuel biological productivity and shape the hyporheic-riparian habitats. For example, floods promote faunal activity and decomposition by increasing the supply of oxygenated water in downwelling areas, while the following recession periods tend to provide stable thermal conditions favoured by fish or insects in areas of groundwater upwelling. This 3-D modelling study investigates the effect of stream stage transience (with events characterised by their intensity and duration) on hydrological exchanges between the surface and the near-stream subsurface. It evaluates, in particular, its effect on streams of varying sinuosity by quantifying the dynamic response of: (1) subsurface flow paths, (2) the exchange pattern at the sediment-water interface, and (3) integrative measures such as total exchange flux and total storage. Understanding geomorphological controls on groundwater/surface water interactions is attractive because topography is generally better constrained than subsurface parameters, and can be used in data-poor situations. The numerical model represents a hypothetical alluvial plain limited by impervious bedrock on all four sides, and in which the channel meanders according to the sine-generated curve of Langbein and Leopold (1966). As the model (HydroGeoSphere) couples surface and subsurface flow, the stream stage transience is imposed by a fluctuating head at the channel inlet. Preliminary results show that a simple rectangular flood pulse in an idealised sinuous stream without additional complexity can generate multiple flow direction reversals at a single point in the channel. The initial conditions of the groundwater table, the channel sinuosity and the time characteristics of the flood pulse all control exchange flow features in different ways. Results are also compared with 'bank storage' analytical solutions that typically assume a straight channel. The discussion covers an evaluation of this work with respect to previous studies that considered the influence of sinuosity on interfacial exchange flows. It addresses the issue of steady vs. transient exchanges, which is of uppermost importance at the operational scale of river restoration schemes. Langbein WB, Leopold LB. 1966. River meanders - theory of minimum variance. U.S. Geol. Surv. Prof. Pap. 422-H: 15 p.

Reviving the "Ganges Water Machine": where and how much?

NASA Astrophysics Data System (ADS)

Muthuwatta, Lal; Amarasinghe, Upali A.; Sood, Aditya; Surinaidu, Lagudu

2017-05-01

Runoff generated in the monsoon months in the upstream parts of the Ganges River basin (GRB) contributes substantially to downstream floods, while water shortages in the dry months affect agricultural production in the basin. This paper examines the potential for subsurface storage (SSS) in the Ganges basin to mitigate floods in the downstream areas and increase the availability of water during drier months. The Soil and Water Assessment Tool (SWAT) is used to estimate sub-basin water availability. The water availability estimated is then compared with the sub-basin-wise unmet water demand for agriculture. Hydrological analysis reveals that some of the unmet water demand in the sub-basin can be met provided it is possible to capture the runoff in sub-surface storage during the monsoon season (June to September). Some of the groundwater recharge is returned to the stream as baseflow and has the potential to increase dry season river flows. To examine the impacts of groundwater recharge on flood inundation and flows in the dry season (October to May), two groundwater recharge scenarios are tested in the Ramganga sub-basin. Increasing groundwater recharge by 35 and 65 % of the current level would increase the baseflow during the dry season by 1.46 billion m3 (34.5 % of the baseline) and 3.01 billion m3 (71.3 % of the baseline), respectively. Analysis of pumping scenarios indicates that 80 000 to 112 000 ha of additional wheat area can be irrigated in the Ramganga sub-basin by additional SSS without reducing the current baseflow volumes. Augmenting SSS reduces the peak flow and flood inundated areas in Ramganga (by up to 13.0 % for the 65 % scenario compared to the baseline), indicating the effectiveness of SSS in reducing areas inundated under floods in the sub-basin. However, this may not be sufficient to effectively control the flood in the downstream areas of the GRB, such as in the state of Bihar (prone to floods), which receives a total flow of 277 billion m3 from upstream sub-basins.

Front gardens to car parks: changes in garden permeability and effects on flood regulation.

PubMed

Warhurst, Jennifer R; Parks, Katherine E; McCulloch, Lindsay; Hudson, Malcolm D

2014-07-01

This study addresses the consequences of widespread conversion of permeable front gardens to hard standing car parking surfaces, and the potential consequences in high-risk urban flooding hotspots, in the city of Southampton. The last two decades has seen a trend for domestic front gardens in urban areas to be converted for parking, driven by the lack of space and increased car ownership. Despite media and political attention, the effects of this change are unknown, but increased and more intense rainfall, potentially linked to climate change, could generate negative consequences as runoff from impermeable surfaces increases. Information is limited on garden permeability change, despite the consequences for ecosystem services, especially flood regulation. We focused on eight flooding hotspots identified by the local council as part of a wider urban flooding policy response. Aerial photographs from 1991, 2004 and 2011 were used to estimate changes in surface cover and to analyse permeability change within a digital surface model in a GIS environment. The 1, 30 and 100 year required attenuation storage volumes were estimated, which are the temporary storage required to reduce the peak flow rate given surface permeability. Within our study areas, impermeable cover in domestic front gardens increased by 22.47% over the 20-year study period (1991-2011) and required attenuation storage volumes increased by 26.23% on average. These increases suggest that a consequence of the conversion of gardens to parking areas will be a potential increase in flooding frequency and severity - a situation which is likely to occur in urban locations worldwide. Copyright © 2014 Elsevier B.V. All rights reserved.

Use of flux and morphologic sediment budgets for sandbar monitoring on the Colorado River in Marble Canyon, Arizona

USGS Publications Warehouse

Grams, Paul E.; Buscombe, Daniel D.; Topping, David J.; Hazel, Joseph E.; Kaplinski, Matt

2015-01-01

The magnitude and pfattern of streamflow and sediment supply of the Colorado River in Grand Canyon (Figure 1) has been affected by the existence and operations of Glen Canyon Dam since filling of Lake Powell Reservoir began in March 1963. In the subsequent 30 years, fine sediment was scoured from the downstream channel (Topping et al., 2000; Grams et al., 2007), resulting in a decline in the number and size of sandbars in the eastern half of Grand Canyon National Park (Wright et al., 2005; Schmidt et al., 2004). The Glen Canyon Dam Adaptive Management Program (GCDAMP) administered by the U.S. Department of Interior oversees efforts to manage the Colorado River ecosystem downstream from Glen Canyon Dam. One of the goals of the GCDAMP is to maintain and increase the number and size of sandbars in this context of a limited sand supply. Management actions to benefit sandbars have included curtailment of daily streamflow fluctuations, which occur for hydropower generation, and implementation of controlled floods, also called high-flow experiments.Studies of controlled floods, defined as intentional releases that exceed the maximum discharge capacity of the Glen Canyon Dam powerplant, implemented between 1996 and 2008, have demonstrated that these events cause increases in sandbar size throughout Marble and Grand Canyons (Hazel et al., 2010; Schmidt and Grams, 2011; Mueller et al., 2014), although the magnitude of response is spatially variable (Hazel et al., 1999; 2010). Controlled floods may build some sandbars at the expense of erosion of sand from other, upstream, sandbars (Schmidt, 1999). To increase the frequency and effectiveness of sandbar building, the U.S. Department of Interior adopted a “high-flow experimental protocol” to implement controlled floods regularly under conditions of enriched sand supply (U.S. Department of Interior, 2012). Because the supply of sand available to build sandbars has been substantially reduced by Glen Canyon Dam (Topping et al., 2000) and depends entirely on infrequent tributary floods, monitoring of both sandbars and gross sand storage (the sand budget) is required to evaluate whether the high-flow protocol is having the intended effect of increasing sandbar size without progressively depleting sand from the system.There are many challenges associated with monitoring sand storage and active sand deposits in a river system as large and complex as the 450-km segment of the Colorado River between Glen Canyon Dam and Lake Mead. Previous studies have demonstrated the temporal variation in sand storage associated with sand-supply limitation (Topping et al., 2000) and the spatial variability in the amount of sand stored in eddies and the channel associated with channel hydraulics (Grams et al., 2013). In this study, we report on companion measurements of sand flux and morphologic change to quantify, for the first time, the relation between changes in sand mass balance, changes in within-channel sand storage, and changes in sandbars comprehensively for a 50-km river segment of the Colorado River in lower Marble Canyon within Grand Canyon National Park.We show that, when measured over the scale of a 50-km river segment, these complementary measurements of the sand budget agree within measurement uncertainty and provide a rare opportunity to integrate the temporally rich sand-flux record with the spatially rich morphologic measurements. Both methods show that sediment was evacuated from lower Marble Canyon over the 3-year study period. The flux-based budget shows the timing of changes in storage relative to dam-release patterns, while the morphologic measurements depict the spatial distribution of erosion and deposition among different depositional settings.

Enhancing water supply through reservoir reoperation

NASA Astrophysics Data System (ADS)

Rajagopal, S.; Sterle, K. M.; Jose, L.; Coors, S.; Pohll, G.; Singletary, L.

2017-12-01

Snowmelt is a significant contributor to water supply in western U.S. which is stored in reservoirs for use during peak summer demand. The reservoirs were built to satisfy multiple objectives, but primarily to either enhance water supply and/or for flood mitigation. The operating rules for these water supply reservoirs are based on historical assumptions of stationarity of climate, assuming peak snowmelt occurs after April 1 and hence have to let water pass through if it arrived earlier. Using the Truckee River which originates in the eastern Sierra Nevada, has seven reservoirs and is shared between California and Nevada as an example, we show enhanced water storage by altering reservoir operating rules. These results are based on a coupled hydrology (Ground-Surface water Flow, GSFLOW) and water management model (RIverware) developed for the river system. All the reservoirs in the system benefit from altering the reservoir rules, but some benefit more than others. Prosser Creek reservoir for example, historically averaged 76% of capacity, which was lowered to 46% of capacity in the future as climate warms and shifts snowmelt to earlier days of the year. This reduction in storage can be mitigated by altering the reservoir operation rules and the reservoir storage increases to 64-76% of capacity. There are limitations to altering operating rules as reservoirs operated primarily for flood control are required to maintain lower storage to absorb a flood pulse, yet using modeling we show that there are water supply benefits to adopting a more flexible rules of operation. In the future, due to changing climate we anticipate the reservoirs in the western U.S. which were typically capturing spring- summer snowmelt will have to be managed more actively as the water stored in the snowpack becomes more variable. This study presents a framework for understanding, modeling and quantifying the consequences of such a shift in hydrology and water management.

Direct and indirect controls on organic matter decomposition in four coastal wetland communities along a landscape salinity gradient

USGS Publications Warehouse

Stagg, Camille L.; Baustian, Melissa M.; Perry, Carey L.; Carruthers, Tim J.B.; Hall, Courtney T.

2018-01-01

Coastal wetlands store more carbon than most ecosystems globally. As sea level rises, changes in flooding and salinity will potentially impact ecological functions, such as organic matter decomposition, that influence carbon storage. However, little is known about the mechanisms that control organic matter loss in coastal wetlands at the landscape scale. As sea level rises, how will the shift from fresh to salt-tolerant plant communities impact organic matter decomposition? Do long-term, plant-mediated, effects of sea-level rise differ from direct effects of elevated salinity and flooding?We identified internal and external factors that regulated indirect and direct pathways of sea-level rise impacts, respectively, along a landscape-scale salinity gradient that incorporated changes in wetland type (fresh, oligohaline, mesohaline and polyhaline marshes). We found that indirect and direct impacts of sea-level rise had opposing effects on organic matter decomposition.Salinity had an indirect effect on litter decomposition that was mediated through litter quality. Despite significant variation in environmental conditions along the landscape gradient, the best predictors of above- and below-ground litter decomposition were internal drivers, initial litter nitrogen content and initial litter lignin content respectively. Litter decay constants were greatest in the oligohaline marsh and declined with increasing salinity, and the fraction of litter remaining (asymptote) was greatest in the mesohaline marsh. In contrast, direct effects of salinity and flooding were positive. External drivers, salinity and flooding, stimulated cellulytic activity, which was highest in the polyhaline marsh.Synthesis. Our results indicate that as sea level rises, initial direct effects of salinity will stimulate decay of labile carbon, but over time as plant communities shift from fresh to polyhaline marsh, litter decay will decline, yielding greater potential for long-term carbon storage. These findings highlight the importance of quantifying carbon loss at multiple temporal scales, not only in coastal wetlands but also in other ecosystems where plant-mediated responses to climate change will have significant impacts on carbon cycling.

Blanket peatland restoration leads to reduced storm runoff from headwater systems

NASA Astrophysics Data System (ADS)

Shuttleworth, Emma; Allott, Tim; Evans, Martin; Pilkington, Mike

2016-04-01

This paper presents data on the impact of largescale peatland restoration on catchment runoff from peatlands in northern England. The blanket peatlands of the Pennine hills are important sources of water supply and form the headwaters of major river systems. These peatlands are severely eroded with extensive gullying and bare peat resulting from the impacts of industrial pollution, overgrazing, wildfire and climatic change over the last millennium. In the last decade there has been a major programme of peatland restoration through re-vegetation and blocking of drainage lines in these systems. The Making Space for Water project has collected hydrological data from five micro-catchments(two restoration treatments, a bare peat control, a vegetated control and a previously restored site) over a four year period. This has allowed for both Before-After-Control-Intervention and Space for Time analysis of the impact of restoration on downstream runoff. Catchments became wetter following re-vegetation, water tables rose by 35 mm and overland flow production increased by 18%. Storm-flow lag times in restored catchments increased by up to 267 %, while peak storm discharge decreased by up to 37%. There were no statistically significant changes in percentage runoff, indicating limited changes to within-storm catchment storage. Natural flood management solutions are typically focussed around one of two main mechanisms, either enhanced storage of water in catchments or measures which slow transmission of water to channels and within channels. Upland peatlands are often mischaracterised as sponges and assumed to mitigate downstream runoff through additional storage. The results of this study suggest that whilst restoration of upland peatlands can lead to significant reductions in peak discharge, and has potential to contribute to natural flood risk management, the mechanism is an increase in catchment roughness and an associated decrease in flow velocities.

A simple inertial formulation of the shallow water equations for efficient two-dimensional flood inundation modelling

NASA Astrophysics Data System (ADS)

Bates, Paul D.; Horritt, Matthew S.; Fewtrell, Timothy J.

2010-06-01

SummaryThis paper describes the development of a new set of equations derived from 1D shallow water theory for use in 2D storage cell inundation models where flows in the x and y Cartesian directions are decoupled. The new equation set is designed to be solved explicitly at very low computational cost, and is here tested against a suite of four test cases of increasing complexity. In each case the predicted water depths compare favourably to analytical solutions or to simulation results from the diffusive storage cell code of Hunter et al. (2005). For the most complex test involving the fine spatial resolution simulation of flow in a topographically complex urban area the Root Mean Squared Difference between the new formulation and the model of Hunter et al. is ˜1 cm. However, unlike diffusive storage cell codes where the stable time step scales with (1/Δ x) 2, the new equation set developed here represents shallow water wave propagation and so the stability is controlled by the Courant-Freidrichs-Lewy condition such that the stable time step instead scales with 1/Δ x. This allows use of a stable time step that is 1-3 orders of magnitude greater for typical cell sizes than that possible with diffusive storage cell models and results in commensurate reductions in model run times. For the tests reported in this paper the maximum speed up achieved over a diffusive storage cell model was 1120×, although the actual value seen will depend on model resolution and water surface gradient. Solutions using the new equation set are shown to be grid-independent for the conditions considered and to have an intuitively correct sensitivity to friction, however small instabilities and increased errors on predicted depth were noted when Manning's n = 0.01. The new equations are likely to find widespread application in many types of flood inundation modelling and should provide a useful additional tool, alongside more established model formulations, for a variety of flood risk management studies.

Reservoir operations under climate change: Storage capacity options to mitigate risk

NASA Astrophysics Data System (ADS)

Ehsani, Nima; Vörösmarty, Charles J.; Fekete, Balázs M.; Stakhiv, Eugene Z.

2017-12-01

Observed changes in precipitation patterns, rising surface temperature, increases in frequency and intensity of floods and droughts, widespread melting of ice, and reduced snow cover are some of the documented hydrologic changes associated with global climate change. Climate change is therefore expected to affect the water supply-demand balance in the Northeast United States and challenge existing water management strategies. The hydrological implications of future climate will affect the design capacity and operating characteristics of dams. The vulnerability of water resources systems to floods and droughts will increase, and the trade-offs between reservoir releases to maintain flood control storage, drought resilience, ecological flow, human water demand, and energy production should be reconsidered. We used a Neural Networks based General Reservoir Operation Scheme to estimate the implications of climate change for dams on a regional scale. This dynamic daily reservoir module automatically adapts to changes in climate and re-adjusts the operation of dams based on water storage level, timing, and magnitude of incoming flows. Our findings suggest that the importance of dams in providing water security in the region will increase. We create an indicator of the Effective Degree of Regulation (EDR) by dams on water resources and show that it is expected to increase, particularly during drier months of year, simply as a consequence of projected climate change. The results also indicate that increasing the size and number of dams, in addition to modifying their operations, may become necessary to offset the vulnerabilities of water resources systems to future climate uncertainties. This is the case even without considering the likely increase in future water demand, especially in the most densely populated regions of the Northeast.

Estimation of flood-frequency characteristics of small urban streams in North Carolina

USGS Publications Warehouse

Robbins, J.C.; Pope, B.F.

1996-01-01

A statewide study was conducted to develop methods for estimating the magnitude and frequency of floods of small urban streams in North Carolina. This type of information is critical in the design of bridges, culverts and water-control structures, establishment of flood-insurance rates and flood-plain regulation, and for other uses by urban planners and engineers. Concurrent records of rainfall and runoff data collected in small urban basins were used to calibrate rainfall-runoff models. Historic rain- fall records were used with the calibrated models to synthesize a long- term record of annual peak discharges. The synthesized record of annual peak discharges were used in a statistical analysis to determine flood- frequency distributions. These frequency distributions were used with distributions from previous investigations to develop a database for 32 small urban basins in the Blue Ridge-Piedmont, Sand Hills, and Coastal Plain hydrologic areas. The study basins ranged in size from 0.04 to 41.0 square miles. Data describing the size and shape of the basin, level of urban development, and climate and rural flood charac- teristics also were included in the database. Estimation equations were developed by relating flood-frequency char- acteristics to basin characteristics in a generalized least-squares regression analysis. The most significant basin characteristics are drainage area, impervious area, and rural flood discharge. The model error and prediction errors for the estimating equations were less than those for the national flood-frequency equations previously reported. Resulting equations, which have prediction errors generally less than 40 percent, can be used to estimate flood-peak discharges for 2-, 5-, 10-, 25-, 50-, and 100-year recurrence intervals for small urban basins across the State assuming negligible, sustainable, in- channel detention or basin storage.

Quick Release of Internal Water Storage in a Glacier Leads to Underestimation of the Hazard Potential of Glacial Lake Outburst Floods From Lake Merzbacher in Central Tian Shan Mountains

NASA Astrophysics Data System (ADS)

Shangguan, Donghui; Ding, Yongjian; Liu, Shiyin; Xie, Zunyi; Pieczonka, Tino; Xu, Junli; Moldobekov, Bolot

2017-10-01

Glacial meltwater and ice calving contribute to the flood volume of glacial lakes such as Lake Merzbacher in the Tian Shan Mountains of central Asia. In this study, we simulated the lake's volume by constructing an empirical relationship between the area of Lake Merzbacher, determined from satellite images, and the lake's water storage, derived from digital elevation models. Results showed that the lake water supply rate before Glacial Lake Outburst Floods (GLOFs) generally agreed well with those during the GLOFs from 2009 to 2012 but not in 2008 and 2015. Furthermore, we found that the combination of glacial meltwater and ice calving is not enough to fully explain the supply rate during GLOFs in 1996 and 1999, suggesting other factors affect the supply rate during GLOFs as well. To examine this further, we compared the water supply rate before and during GLOF events in 1999 and 2008. We inferred that quickly released short-term and intermediate-term water storage by glaciers have likely contributed to both flood events in those years. This study highlights the need to improve our understanding of the supply component of outburst floods, such as irregularly released stored water may lead to GLOF events with generally three different types: case I (singular event-triggered englacial water release), case II (glacier melt due to temperature changes), and case III (englacial water release mixed with glacier melt).

Adaptation to flooding during emergence and seedling growth in rice and weeds, and implications for crop establishment

PubMed Central

Ismail, Abdelbagi M.; Johnson, David E.; Ella, Evangelina S.; Vergara, Georgina V.; Baltazar, Aurora M.

2012-01-01

Background and aims Direct seeding of rice is being adopted in rainfed and irrigated lowland ecosystems because it reduces labour costs in addition to other benefits. However, early flooding due to uneven fields or rainfall slows down seed germination and hinders crop establishment. Conversely, early flooding helps suppress weeds and reduces the costs of manual weeding and/or dependence on herbicides; however, numerous weed species are adapted to lowlands and present challenges for the use of flooding to control weeds. Advancing knowledge on the mechanisms of tolerance of flooding during germination and early growth in rice and weeds could facilitate the development of improved rice varieties and effective weed management practices for direct-seeded rice. Principal results Rice genotypes with a greater ability to germinate and establish in flooded soils were identified, providing opportunities to develop varieties suitable for direct seeding in flooded soils. Tolerance of flooding in these genotypes was mostly attributed to traits associated with better ability to mobilize stored carbohydrates and anaerobic metabolism. Limited studies were undertaken in weeds associated with lowland rice systems. Remaining studies compared rice and weeds and related weed species such as Echinochloa crus-galli and E. colona or compared ecotypes of the same species of Cyperus rotundus adapted to either aerobic or flooded soils. Conclusions Tolerant weeds and rice genotypes mostly developed similar adaptive traits that allow them to establish in flooded fields, including the ability to germinate and elongate faster under hypoxia, mobilize stored starch reserves and generate energy through fermentation pathways. Remarkably, some weeds developed additional traits such as larger storage tubers that enlarge further in deeper flooded soils (C. rotundus). Unravelling the mechanisms involved in adaptation to flooding will help design management options that will allow tolerant rice genotypes to adequately establish in flooded soils while simultaneously suppressing weeds. PMID:22957137

Scaling the flood regime with the soil hydraulic properties of the catchment

NASA Astrophysics Data System (ADS)

Peña Rojas, Luis Eduardo; Francés García, Félix; Barrios Peña, Miguel

2015-04-01

The spatial land cover distribution and soil type affect the hydraulic properties of soils, facilitating or retarding the infiltration rate and the response of a catchment during flooding events. This research analyzes: 1) the effect of land cover use in different time periods as a source of annual maximum flood records nonstationarity; 2) the scalability of the relationship between soil hydraulic properties of the catchment (initial abstractions, upper soil capillary storage and vertical and horizontal hydraulic conductivity) and the flood regime. The study was conducted in Combeima River basin in Colombia - South America and it was modelled the changes in the land uses registered in 1991, 2000, 2002 and 2007, using distributed hydrological modelling and nonparametric tests. The results showed that changes in land use affect hydraulic properties of soil and it has influence on the magnitude of flood peaks. What is a new finding is that this behavior is scalable with the soil hydraulic properties of the catchment flood moments have a simple scaling behavior and the peaks flow increases with higher values of capillary soil storage, whereas higher values, the peaks decreased. Finally it was applied Generalized Extreme Values and it was found scalable behavior in the parameters of the probability distribution function. The results allowed us to find a relationship between soil hydraulic properties and the behavior of flood regime in the basin studied.

Validation of satellite-based operational flood monitoring in Southern Queensland, Australia

NASA Astrophysics Data System (ADS)

Gouweleeuw, Ben; Ticehurst, Catherine; Lerat, Julien; Thew, Peter

2010-05-01

The integration of remote sensing observations with stage data and flood modeling has the potential to provide improved support to a number of disciplines, such as flood warning emergency response and operational water resources management. The ability of remote sensing technology to monitor the dynamics of hydrological events lies in its capacity to map surface water. For flood monitoring, remote sensing imagery needs to be available sufficiently frequently to capture subsequent inundation stages. MODIS optical data are available at a moderately high spatial and temporal resolution (250m-1km, twice daily), but are affected by cloud cover. AMSR-E passive microwave observations are available at comparable temporal resolution, but coarse spatial resolution (5-70km), where the smaller footprints corresponds with the higher frequency bands, which are affected by precipitating clouds. A novel operational technique to monitor flood extent combines MODIS reflectance and AMSR-E passive microwave imagery to optimize data continuity. Flood extent is subsequently combined with a DEM to obtain total flood water volume. The flood extent and volume product is operational for the lower-Balonne floodplain in Southern Queensland, Australia. For validation purposes, two moderate flood events coinciding with the MODIS and AMSR-E sensor lifetime are evaluated. The flood volume estimated from MODIS/AMSR-E images gives an accurate indication of both the timing and the magnitude of the flood peak compared to the net volume from recorded flow. In the flood recession, however, satellite-derived water volume declines rapidly, while the net flow volume remains level. This may be explained by a combination of ungauged outflows, soil infiltration, evaporation and diversion of flood water into many large open reservoirs for irrigation purposes. The open water storage extent unchanged, the water volume product is not sensitive enough to capture the change in storage water level. Additional information on the latter, e.g. via telemetered buoys, may circumvent this limitation.

Techniques for estimating flood hydrographs for ungaged urban watersheds

USGS Publications Warehouse

Stricker, V.A.; Sauer, V.B.

1984-01-01

The Clark Method, modified slightly was used to develop a synthetic, dimensionless hydrograph which can be used to estimate flood hydrographs for ungaged urban watersheds. Application of the technique results in a typical (average) flood hydrograph for a given peak discharge. Input necessary to apply the technique is an estimate of basin lagtime and the recurrence interval peak discharge. Equations for this purpose were obtained from a recent nationwide study on flood frequency in urban watersheds. A regression equation was developed which relates flood volumes to drainage area size, basin lagtime, and peak discharge. This equation is useful where storage of floodwater may be a part of design of flood prevention. (USGS)

Effects of Hydrologic Restoration on Flood Resilience and Sediment Dynamics of Urban Creeks in the UK and USA

NASA Astrophysics Data System (ADS)

Wright, N.

2015-12-01

Hydrologic restoration in urban creeks is increasingly regarded as a more sustainable option than traditional grey infrastructures in many countries including the UK and USA. Hydrologic restoration aims to recreate naturally oriented hydro-morphodynamic processes while adding ecological and amenity value to a river corridor. Nevertheless, the long-term hydraulic performance of river restorations is incompletely understood. The aim of this research was to investigate the long-term effects of river restoration on the water storage, flood attenuation and sediment dynamics of two urban creeks through detailed hydro-morphodynamic modelling. The first case study is based on Johnson Creek located at Portland, Oregon, USA, and the second case based on Ouseburn River in Newcastle upon Tyne, N.E. England. This study focuses on the downstream of the Johnson Creek, where creek is reconnected to a restored East Lents floodplain of 0.28 km2. In order to offset the increased urban runoff in the Ouseburn catchment, a number of attenuation ponds were implemented along the river. In this study, an integrated 1D and 2D flood model (ISIS - TUFLOW) and the recently updated layer-based hydro-morphodynamic model have been used to understand the long-term impacts of these restorations on the flood and sediment dynamics. The event-based simulations (500 year, 100 year, 50 year, 10 year and 5 year), as well as the continuous simulations based on the historical flow datasets were systematically undertaken. Simulation results showed that the flood storage as a result of river restoration attenuate the flood peak by up to 25% at the downstream. Results also indicated that about 30% of the sediments generated from the upstream deposited in the resorted regions. The spatial distribution and amount of short and long-term sediment deposition on the floodplain and pond are demonstrated, and the resulting potential loss of the flood storage capacity are analysed and discussed.

Streamflow model of Wisconsin River for estimating flood frequency and volume

USGS Publications Warehouse

Krug, William R.; House, Leo B.

1980-01-01

The 100-year flood peak at Wisconsin Dells, computed from the simulated, regulated streamflow data for the period 1915-76, is 82,000 cubic feet per second, including the effects of all the reservoirs in the river system, as they are currently operated. It also includes the effects of Lakes Du Bay, Petenwell, and Castle Rock which are significant for spring floods but are insignificant for summer or fall floods because they are normally maintained nearly full in the summer and fall and have very little storage for floodwaters. (USGS)

Beaver Mediated Water Table Dynamics in Mountain Peatlands

NASA Astrophysics Data System (ADS)

Karran, D. J.; Westbrook, C.; Bedard-Haughn, A.

2016-12-01

Water table dynamics play an important role in the ecological and biogeochemical processes that regulate carbon and water storage in peatlands. Beaver are common in these habitats and the dams they build have been shown to raise water tables in other environments. However, the impact of beaver dams in peatlands, where water tables rest close to the surface, has yet to be determined. We monitored a network of 50 shallow wells in a Canadian Rocky Mountain peatland for 6 years. During this period, a beaver colony was maintaining a number of beaver ponds for four years until a flood event removed the colony from the area and breached some of the dams. Two more years of data were collected after the flood event to assess whether the dams enhanced groundwater storage. Beaver dams raised water tables just as they do in other environments. Furthermore, water tables within 100 meters of beaver dams were more stable than those further away and water table stability overall was greater before the flood event. Our results suggest the presence/absence of beaver in peatlands has implications for groundwater water storage and overall system function.

Natural phenomena evaluations of the K-25 site UF{sub 6} cylinder storage yards

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fricke, K.E.

1996-09-15

The K-25 Site UF{sub 6} cylinder storage yards are used for the temporary storage of UF{sub 6} normal assay cylinders and long-term storage of other UF{sub 6} cylinders. The K-25 Site UF{sub 6} cylinder storage yards consist of six on-site areas: K-1066-B, K-1066-E, K-1066-F, K-1066-J, K-1066-K and K-1066-L. There are no permanent structures erected on the cylinder yards, except for five portable buildings. The operating contractor for the K-25 Site is preparing a Safety Analysis Report (SAR) to examine the safety related aspects of the K-25 Site UF{sub 6} cylinder storage yards. The SAR preparation encompasses many tasks terminating inmore » consequence analysis for the release of gaseous and liquid UF{sub 6}, one of which is the evaluation of natural phenomena threats, such as earthquakes, floods, and winds. In support of the SAR, the six active cylinder storage yards were evaluated for vulnerabilities to natural phenomena, earthquakes, high winds and tornados, tornado-generated missiles, floods (local and regional), and lightning. This report summarizes those studies. 30 refs.« less

Analysis of Groundwater Anomalies Estimated by GRACE and GLDAS Satellite-based Hydrological Model in the Gulf of Mexico

NASA Astrophysics Data System (ADS)

Lotfata, A.; Ambinakudige, S.

2017-12-01

Coastal regions face a higher risk of flooding. A rise in sea-level increases flooding chances in low-lying areas. A major concern is the effect of sea-level rise on the depth of the fresh water/salt water interface in the aquifers of the coastal regions. A sea-level change rise impacts the hydrological system of the aquifers. Salt water intrusion into fresh water aquifers increase water table levels. Flooding prone areas in the coast are at a higher risk of salt water intrusion. The Gulf coast is one of the most vulnerable flood areas due to its natural weather patterns. There is not yet a local assessment of the relation between groundwater level and sea-level rising. This study investigates the projected sea-level rise models and the anomalous groundwater level during January 2002 to December 2016. We used the NASA Gravity Recovery and Climate Experiment (GRACE) and Global Land Data Assimilation System (GLDAS) satellite data in the analysis. We accounted the leakage error and the measurement error in GRACE data. GLDAS data was used to calculate the groundwater storage from the total water storage estimated using GRACE data (ΔGW=ΔTWS (soil moisture, surface water, groundwater, and canopy water) - ΔGLDAS (soil moisture, surface water, and canopy water)). The preliminary results indicate that the total water storage is increasing in parts of the Gulf of Mexico. GRACE data show high soil wetness and groundwater levels in Mississippi, Alabama and Texas coasts. Because sea-level rise increases the probability of flooding in the Gulf coast and affects the groundwater, we will analyze probable interactions between sea-level rise and groundwater in the study area. To understand regional sea-level rise patterns, we will investigate GRACE Ocean data along the Gulf coasts. We will quantify ocean total water storage, its salinity, and its relationship with the groundwater level variations in the Gulf coast.

Evaluating the efficacy of distributed detention structures to reduce downstream flooding under variable rainfall, antecedent soil, and structural storage conditions

NASA Astrophysics Data System (ADS)

Thomas, Nicholas W.; Arenas Amado, Antonio; Schilling, Keith E.; Weber, Larry J.

2016-10-01

This research systematically analyzed the influence of antecedent soil wetness, rainfall depth, and the subsequent impact on peak flows in a 45 km2 watershed. Peak flows increased with increasing antecedent wetness and rainfall depth, with the highest peak flows occurring under intense precipitation on wet soils. Flood mitigation structures were included and investigated under full and empty initial storage conditions. Peak flows were reduced at the outlet of the watershed by 3-17%. The highest peak flow reductions occurred in scenarios with dry soil, empty project storage, and low rainfall depths. These analyses showed that with increased rainfall depth, antecedent moisture conditions became increasingly less impactful. Scaling invariance of peak discharges were shown to hold true within this basin and were fit through ordinary least squares regression for each design scenario. Scale-invariance relationships were extrapolated beyond the outlet of the analyzed basin to the point of intersection of with and without structure scenarios. In each scenario extrapolated peak discharge benefits depreciated at a drainage area of approximately 100 km2. The associated drainage area translated to roughly 2 km downstream of the Beaver Creek watershed outlet. This work provides an example of internal watershed benefits of structural flood mitigation efforts, and the impact the may exert outside of the basin. Additionally, the influence of 1.8 million in flood reduction tools was not sufficient to routinely address downstream flood concerns, shedding light on the additional investment required to alter peak flows in large basins.

Lake Darling Flood Control Project, Souris River, North Dakota. General Project Design.

DTIC Science & Technology

1983-06-01

contribute significantly to waterfowl production and provide resting areas for migrating waterfowl. Their upland and wooded areas support deer and small...of storage over about 370 acres of grass and wooded lands. Addition of a dam on Gassman Coulee would eliminate the threat of severe damages and loss...Renville County. Although rustic, the wooded area is also a haven from the sun and wind which is so prevalent on the North Dakota plains. There are

33 CFR 208.11 - Regulations for use of storage allocated for flood control or navigation and/or project operation...

Code of Federal Regulations, 2012 CFR

2012-07-01

... Lk KS Mitchel Solomon R FIM 722.3204.8 1488.31455.6 1455.61428.0 3368212602 126023341 PL 78-534PL 79....34051.0 137309410 9410820 PL 78-534 USBR. Kirwin Dam & Res KS Phillips N Fork Solomon R FICR 215.189.6... 1330 890 PL 78-534 VT Webster Dam & Res KS Rocks S Fork Solomon R FIRC 183.472.1 1923.71892.5 1892...

33 CFR 208.11 - Regulations for use of storage allocated for flood control or navigation and/or project operation...

Code of Federal Regulations, 2013 CFR

2013-07-01

... Lk KS Mitchel Solomon R FIM 722.3204.8 1488.31455.6 1455.61428.0 3368212602 126023341 PL 78-534PL 79....34051.0 137309410 9410820 PL 78-534 USBR. Kirwin Dam & Res KS Phillips N Fork Solomon R FICR 215.189.6... 1330 890 PL 78-534 VT Webster Dam & Res KS Rocks S Fork Solomon R FIRC 183.472.1 1923.71892.5 1892...

33 CFR 208.11 - Regulations for use of storage allocated for flood control or navigation and/or project operation...

Code of Federal Regulations, 2014 CFR

2014-07-01

... Lk KS Mitchel Solomon R FIM 722.3204.8 1488.31455.6 1455.61428.0 3368212602 126023341 PL 78-534PL 79....34051.0 137309410 9410820 PL 78-534 USBR. Kirwin Dam & Res KS Phillips N Fork Solomon R FICR 215.189.6... 1330 890 PL 78-534 VT Webster Dam & Res KS Rocks S Fork Solomon R FIRC 183.472.1 1923.71892.5 1892...

Evaluation of Modern Navies’ Damage Control and Firefighting Training using Simulator Platforms

DTIC Science & Technology

2011-09-01

Figure 18 below is a two-story concrete structure including holes in bulkheads, ruptured pipelines, and almost all situations that can cause flooding...the four simulators address Class A, B, and C fires. The first one—the “Basic Firefighting Trainer”—is a single-story concrete structure with four...Figure 19—is a three-story concrete structure that houses berthing facilities, engine rooms, storage compartments and electrical and engine room mock

[Effect of water storage and aquaculture on Oncomelania hupensis control in tidal flats wetlands of islet-beach type area of Dantu section of lower reaches of Yangtze River].

PubMed

Li, Ye-fang; Huang, Yi-xin; Wang, He-sheng; Hang, De-rong; Chen, Xiang-ping; Xie, Yi-feng; Zhang, Lian-heng

2015-12-01

To evaluate the effect and the benefits of the projects of water storage and aquaculture on Oncomelania hupensis snail control in the tidal flats wetlands of islet-beach type area of lower reaches of the Yangtze River. The projects of water storage and aquaculture on 0. hupensis snail control were implemented in the tidal flats wetlands of islet-beach type of lower reaches of the Yangtze River. The breed situation of the snails was investigated by the conventional method before and after the project implementation and the effect of control and elimination of the snails by the projects were evaluated. At the same time, the cost-benefit analysis of two projects among them was performed by the static benefit-cost ratio method. All of 0. hupensis snails were eliminated in the first year after the implementation of seven water storage and aquaculture projects. The costs of detection and control of snails saved by each project was 69.20 thousand yuan a year on average. The annual net benefits of the "Nanhao Group 10 beach" project and "Wutao Group 6-14 beach" project were 2 039.40 thousand yuan and 955.00 thousand yuan respectively, and the annual net benefit-cost ratios were 1.09: 1 and 1.07: 1 respectively. The O. hupensis snails could be rapidly eliminated by the water storage and aquaculture, and the economic benefit is obvious, but the wetland ecological protection and flood control safety should be considered in the tidal flats wetlands of islet-beach type area of lower reaches of the Yangtze River.

Global Assessment of Exploitable Surface Reservoir Storage under Climate Change

NASA Astrophysics Data System (ADS)

Liu, L.; Parkinson, S.; Gidden, M.; Byers, E.; Satoh, Y.; Riahi, K.

2016-12-01

Surface water reservoirs provide us with reliable water supply systems, hydropower generation, flood control, and recreation services. Reliable reservoirs can be robust measures for water security and can help smooth out challenging seasonal variability of river flows. Yet, reservoirs also cause flow fragmentation in rivers and can lead to flooding of upstream areas, thereby displacing existing land-uses and ecosystems. The anticipated population growth, land use and climate change in many regions globally suggest a critical need to assess the potential for appropriate reservoir capacity that can balance rising demands with long-term water security. In this research, we assessed exploitable reservoir potential under climate change and human development constraints by deriving storage-yield relationships for 235 river basins globally. The storage-yield relationships map the amount of storage capacity required to meet a given water demand based on a 30-year inflow sequence. Runoff data is simulated with an ensemble of Global Hydrological Models (GHMs) for each of five bias-corrected general circulation models (GCMs) under four climate change pathways. These data are used to define future 30-year inflows in each river basin for time period between 2010 and 2080. The calculated capacity is then combined with geographical information of environmental and human development exclusion zones to further limit the storage capacity expansion potential in each basin. We investigated the reliability of reservoir potentials across different climate change scenarios and Shared Socioeconomic Pathways (SSPs) to identify river basins where reservoir expansion will be particularly challenging. Preliminary results suggest large disparities in reservoir potential across basins: some basins have already approached exploitable reserves, while some others display abundant potential. Exclusions zones pose significant impact on the amount of actual exploitable storage and firm yields worldwide: 30% of reservoir potential would be unavailable because of land occupation by environmental and human development. Results from this study will help decision makers to understand the reliability of infrastructure systems particularly sensitive to future water availability.

An R package for the design, analysis and operation of reservoir systems

NASA Astrophysics Data System (ADS)

Turner, Sean; Ng, Jia Yi; Galelli, Stefano

2016-04-01

We present a new R package - named "reservoir" - which has been designed for rapid and easy routing of runoff through storage. The package comprises well-established tools for capacity design (e.g., the sequent peak algorithm), performance analysis (storage-yield-reliability and reliability-resilience-vulnerability analysis) and release policy optimization (Stochastic Dynamic Programming). Operating rules can be optimized for water supply, flood control and amenity objectives, as well as for maximum hydropower production. Storage-depth-area relationships are in-built, allowing users to incorporate evaporation from the reservoir surface. We demonstrate the capabilities of the software for global studies using thousands of reservoirs from the Global Reservoir and Dam (GRanD) database fed by historical monthly inflow time series from a 0.5 degree gridded global runoff dataset. The package is freely available through the Comprehensive R Archive Network (CRAN).

Development and testing of a simple inertial formulation of the shallow water equations for flood inundation modelling

NASA Astrophysics Data System (ADS)

Fewtrell, Timothy; Bates, Paul; Horritt, Matthew

2010-05-01

This abstract describes the development of a new set of equations derived from 1D shallow water theory for use in 2D storage cell inundation models. The new equation set is designed to be solved explicitly at very low computational cost, and is here tested against a suite of four analytical and numerical test cases of increasing complexity. In each case the predicted water depths compare favourably to analytical solutions or to benchmark results from the optimally stable diffusive storage cell code of Hunter et al. (2005). For the most complex test involving the fine spatial resolution simulation of flow in a topographically complex urban area the Root Mean Squared Difference between the new formulation and the model of Hunter et al. is ~1 cm. However, unlike diffusive storage cell codes where the stable time step scales with (1-?x)2 the new equation set developed here represents shallow water wave propagation and so the stability is controlled by the Courant-Freidrichs-Lewy condition such that the stable time step instead scales with 1-?x. This allows use of a stable time step that is 1-3 orders of magnitude greater for typical cell sizes than that possible with diffusive storage cell models and results in commensurate reductions in model run times. The maximum speed up achieved over a diffusive storage cell model was 1120x in these tests, although the actual value seen will depend on model resolution and water depth and surface gradient. Solutions using the new equation set are shown to be relatively grid-independent for the conditions considered given the numerical diffusion likely at coarse model resolution. In addition, the inertial formulation appears to have an intuitively correct sensitivity to friction, however small instabilities and increased errors on predicted depth were noted when Manning's n = 0.01. These small instabilities are likely to be a result of the numerical scheme employed, whereby friction is acting to stabilise the solution although this scheme is still widely used in practice. The new equations are likely to find widespread application in many types of flood inundation modelling and should provide a useful additional tool, alongside more established model formulations, for a variety of flood risk management studies.

And Then the Rains Came.

ERIC Educational Resources Information Center

Johnson, Betty D.

1996-01-01

Describes how the library staff at Stetson University in central Florida coped with flooding. Offers recommendations on storage; carpeting; fans and humidifiers; emergency phone contacts; labeled keys; protective coverings for books; safe storage for "disaster" materials and equipment; removal of less valuable materials; sandbags;…

ON THE HYDRAULICS OF STREAM FLOW ROUTING WITH BANK STORAGE

EPA Science Inventory

Bank storage is a process in which volumes of water are temporally retained by alluvial stream banks during flood events, and gradually released to partially sustain baseflow. This process has important hydrologic and ecological implications. In this paper, analytical solutions a...

Modeling of n-hexadecane and water sorption in wood

Treesearch

Ganna Baglayeva; Gautham Krishnamoorthy; Charles R. Frihart; Wayne S. Seamus; Jane O’Dell; Evguenii Kozliak

2016-01-01

Contamination of wooden framing structures with semivolatile organic chemicals is a common occurrence from the spillage of chemicals, such as impregnation with fuel oil hydrocarbons during floods. Little information is available to understand the penetration of fuel oil hydrocarbons into wood under ambient conditions. To imitate flood and storage scenarios, the...

Developing tools and procedures for the collection and storage of flood damage data in the aftermath of flood events: the Poli-RISPOSTA project

NASA Astrophysics Data System (ADS)

Molinari, Daniela; Ballio, Francesco; Mazuran, Mirjana; Arias, Carolina; Minucci, Guido; Atun, Funda; Ardagna, Danilo

2015-04-01

According to a recent JRC report (De Groeve et al., Recording disaster losses, 2013), no measure better than loss over time can provide objective understanding of the path towards resilience. Moreover, damage data collected in the aftermath of floods supply the knowledge base on which a blend of actions can be performed, both in the short and mid time after the occurrence of a flood; among them: the identification of priorities for intervention during emergencies, the definition of compensation schemes, the understanding of damage mechanisms and of the fragilities of the flooded areas so as to improve/reform current risk mitigation strategies (also by means of improved flood damage models). Objective "measurement" of flood losses remains inadequate to meet the above objectives. This is due to a number of reasons that include: the diversity of intent for data collection, the lack of standardization on how to collect and storage data (including the lack of agreed definitions) among responsible subjects, and last but not least a lack of legislation to support the collection process. In such a context, the aim of this contribution is to discuss the results from the Poli-RISPOSTA (stRumentI per la protezione civile a Supporto delle POpolazioni nel poST Alluvione) project, a research project founded by Politecnico di Milano which is intended to develop tools and procedures for the collection and storage of high quality, consistent and reliable flood damage data. Specific objectives of Poli-RISPOSTA are: - Develop an operational procedure for collecting, storing and analyzing all damage data, in the aftermath of flood events. Collected data are intended to support a variety of actions, namely: loss accounting, disaster forensic, damage compensation and flood risk modelling; - Develop educational material and modules for training practitioners in the use of the procedure; - Develop enhanced IT tools to support the procedure, easing as much as possible the collection of field data, the creation of databases and the connection between the latter and different regional and municipal databases that already exist for different purposes (from cadastral data, to satellite images, etc.), the processing of collected data. A key principle of Poli-RISPOSTA is developing tools with the direct involvement of all interested parties so as to reach a two-fold objective: producing feasible solutions that re-organise existing practices and integrate them with new ones (whereas they are lacking) and, directly linked to the previous point, supplying the legislative context in which developed tools can be implemented.

A long-term comparison of carbon sequestration rates in impounded and naturally tidal freshwater marshes along the lower Waccamaw River, South Carolina

USGS Publications Warehouse

Drexler, Judith Z.; Krauss, Ken W.; Sasser, M. Craig; Fuller, Christopher C.; Swarzenski, Christopher M.; Powell, Amber; Swanson, Kathleen M.; Orlando, James L.

2013-01-01

Carbon storage was compared between impounded and naturally tidal freshwater marshes along the Lower Waccamaw River in South Carolina, USA. Soil cores were collected in (1) naturally tidal, (2) moist soil (impounded, seasonally drained since ~1970), and (3) deeply flooded “treatments” (impounded, flooded to ~90 cm since ~2002). Cores were analyzed for % organic carbon, % total carbon, bulk density, and 210Pb and 137Cs for dating purposes. Carbon sequestration rates ranged from 25 to 200 g C m−2 yr−1 (moist soil), 80–435 g C m−2 yr−1 (naturally tidal), and 100–250 g C m−2 yr−1 (deeply flooded). The moist soil and naturally tidal treatments were compared over a period of 40 years. The naturally tidal treatment had significantly higher carbon storage (mean = 219 g C m−2 yr−1 vs. mean = 91 g C m−2 yr−1) and four times the vertical accretion rate (mean = 0.84 cm yr−1 vs. mean = 0.21 cm yr−1) of the moist soil treatment. The results strongly suggest that the long drainage period in moist soil management limits carbon storage over time. Managers across the National Wildlife Refuge system have an opportunity to increase carbon storage by minimizing drainage in impoundments as much as practicable.

Estimating flood hydrographs and volumes for Alabama streams

USGS Publications Warehouse

Olin, D.A.; Atkins, J.B.

1988-01-01

The hydraulic design of highway drainage structures involves an evaluation of the effect of the proposed highway structures on lives, property, and stream stability. Flood hydrographs and associated flood volumes are useful tools in evaluating these effects. For design purposes, the Alabama Highway Department needs information on flood hydrographs and volumes associated with flood peaks of specific recurrence intervals (design floods) at proposed or existing bridge crossings. This report will provide the engineer with a method to estimate flood hydrographs, volumes, and lagtimes for rural and urban streams in Alabama with drainage areas less than 500 sq mi. Existing computer programs and methods to estimate flood hydrographs and volumes for ungaged streams have been developed in Georgia. These computer programs and methods were applied to streams in Alabama. The report gives detailed instructions on how to estimate flood hydrographs for ungaged rural or urban streams in Alabama with drainage areas less than 500 sq mi, without significant in-channel storage or regulations. (USGS)

Risk-trading in flood management: An economic model.

PubMed

Chang, Chiung Ting

2017-09-15

Although flood management is no longer exclusively a topic of engineering, flood mitigation continues to be associated with hard engineering options. Flood adaptation or the capacity to adapt to flood risk, as well as a demand for internalizing externalities caused by flood risk between regions, complicate flood management activities. Even though integrated river basin management has long been recommended to resolve the above issues, it has proven difficult to apply widely, and sometimes even to bring into existence. This article explores how internalization of externalities as well as the realization of integrated river basin management can be encouraged via the use of a market-based approach, namely a flood risk trading program. In addition to maintaining efficiency of optimal resource allocation, a flood risk trading program may also provide a more equitable distribution of benefits by facilitating decentralization. This article employs a graphical analysis to show how flood risk trading can be implemented to encourage mitigation measures that increase infiltration and storage capacity. A theoretical model is presented to demonstrate the economic conditions necessary for flood risk trading. Copyright © 2017 Elsevier Ltd. All rights reserved.

Dam pre-release as an important operation strategy in reducing flood impact in Malaysia

NASA Astrophysics Data System (ADS)

Hidayah Ishak, Nurul; Mustafa Hashim, Ahmad

2018-03-01

The 2014 flood was reported to be one of the worst natural disaster has ever affected several states in the northern part of Peninsular Malaysia. Overwhelming rainfall was noted as one of the main factors causing such impact, which was claimed to be unprecedented to some extent. The state of Perak, which is blessed with four cascading dams had also experienced flood damage at a scale that was considered the worst in history. The rainfall received had caused the dam to reach danger level that necessitated additional discharge to be released. Safety of the dams was of great importance and such unavoidable additional discharge was allowed to avoid catastrophic failure of the dam structures. This paper discusses the dam pre-release as a significant dam management strategy in reducing flood impact. An important balance between required dam storage to be maintained and the risk element that can be afforded is the crucial factor in such enhanced operation strategy. While further possibility in developing a carefully engineered dam pre-release strategy can be explored for dam operation in Malaysia, this has already been introduced in some developed countries. Australia and South Africa are examples where pre-release has been practiced and proven to reduce flood risk. The concept involves controlling the dam lake level throughout the year, in reference to the rainfall data and the hydrological properties for the catchment area of the dams. Plentiful data analysis need to be done in contemplation of producing the optimal pre-release model. The amount of heavy rainfalls received is beyond human control but the distribution of the discharge from the dams can be further managed with the appropriate pre-release strategy.

33 CFR 208.11 - Regulations for use of storage allocated for flood control or navigation and/or project operation...

Code of Federal Regulations, 2011 CFR

2011-07-01

... VA Pwr. Glen Elder Dam & Waconda Lk KS Mitchel Solomon R FIM 722.3204.8 1488.31455.6 1455.61428.0... 820 PL 78-534 USBR. Kirwin Dam & Res KS Phillips N Fork Solomon R F ICR 215.1 89.6 1757.3 1729.2 1729... Webster Dam & Res KS Rocks S Fork Solomon R F IRC 183.4 72.1 1923.7 1892.5 1892.5 1860.0 8480 3772 3772...

33 CFR 208.11 - Regulations for use of storage allocated for flood control or navigation and/or project operation...

Code of Federal Regulations, 2010 CFR

2010-07-01

... VA Pwr. Glen Elder Dam & Waconda Lk KS Mitchel Solomon R FIM 722.3204.8 1488.31455.6 1455.61428.0... 820 PL 78-534 USBR. Kirwin Dam & Res KS Phillips N Fork Solomon R F ICR 215.1 89.6 1757.3 1729.2 1729... Webster Dam & Res KS Rocks S Fork Solomon R F IRC 183.4 72.1 1923.7 1892.5 1892.5 1860.0 8480 3772 3772...

Is it worth a dam?

PubMed Central

Joyce, S

1997-01-01

Once a sign of modernization and growth, dams are often seen today as symbols of environmental and social devastation. Over 800,000 dams have been built worldwide to provide drinking water, flood control, hydropower, irrigation, navigation, and water storage. Dams do indeed provide these things,but at the cost of several adverse, unexpected effects: disruption of ecosystems, decline of fish stocks, forced human and animal resettlements, and diseases such as malaria, which are borne by vectors that thrive in quiet waters. PMID:9349830

Integration of Grid and Sensor Web for Flood Monitoring and Risk Assessment from Heterogeneous Data

NASA Astrophysics Data System (ADS)

Kussul, Nataliia; Skakun, Sergii; Shelestov, Andrii

2013-04-01

Over last decades we have witnessed the upward global trend in natural disaster occurrence. Hydrological and meteorological disasters such as floods are the main contributors to this pattern. In recent years flood management has shifted from protection against floods to managing the risks of floods (the European Flood risk directive). In order to enable operational flood monitoring and assessment of flood risk, it is required to provide an infrastructure with standardized interfaces and services. Grid and Sensor Web can meet these requirements. In this paper we present a general approach to flood monitoring and risk assessment based on heterogeneous geospatial data acquired from multiple sources. To enable operational flood risk assessment integration of Grid and Sensor Web approaches is proposed [1]. Grid represents a distributed environment that integrates heterogeneous computing and storage resources administrated by multiple organizations. SensorWeb is an emerging paradigm for integrating heterogeneous satellite and in situ sensors and data systems into a common informational infrastructure that produces products on demand. The basic Sensor Web functionality includes sensor discovery, triggering events by observed or predicted conditions, remote data access and processing capabilities to generate and deliver data products. Sensor Web is governed by the set of standards, called Sensor Web Enablement (SWE), developed by the Open Geospatial Consortium (OGC). Different practical issues regarding integration of Sensor Web with Grids are discussed in the study. We show how the Sensor Web can benefit from using Grids and vice versa. For example, Sensor Web services such as SOS, SPS and SAS can benefit from the integration with the Grid platform like Globus Toolkit. The proposed approach is implemented within the Sensor Web framework for flood monitoring and risk assessment, and a case-study of exploiting this framework, namely the Namibia SensorWeb Pilot Project, is described. The project was created as a testbed for evaluating and prototyping key technologies for rapid acquisition and distribution of data products for decision support systems to monitor floods and enable flood risk assessment. The system provides access to real-time products on rainfall estimates and flood potential forecast derived from the Tropical Rainfall Measuring Mission (TRMM) mission with lag time of 6 h, alerts from the Global Disaster Alert and Coordination System (GDACS) with lag time of 4 h, and the Coupled Routing and Excess STorage (CREST) model to generate alerts. These are alerts are used to trigger satellite observations. With deployed SPS service for NASA's EO-1 satellite it is possible to automatically task sensor with re-image capability of less 8 h. Therefore, with enabled computational and storage services provided by Grid and cloud infrastructure it was possible to generate flood maps within 24-48 h after trigger was alerted. To enable interoperability between system components and services OGC-compliant standards are utilized. [1] Hluchy L., Kussul N., Shelestov A., Skakun S., Kravchenko O., Gripich Y., Kopp P., Lupian E., "The Data Fusion Grid Infrastructure: Project Objectives and Achievements," Computing and Informatics, 2010, vol. 29, no. 2, pp. 319-334.

Glacial vs. Interglacial Period Contrasts in Midlatitude Fluvial Systems, with Examples from Western Europe and the Texas Coastal Plain

NASA Astrophysics Data System (ADS)

Blum, M.

2001-12-01

Mixed bedrock-alluvial valleys are the conveyor belts for sediment delivery to passive continental margins. Mapping, stratigraphic and sedimentologic investigations, and development of geochronological frameworks for large midlatitude rivers of this type, in Western Europe and the Texas Coastal Plain, provide for evaluation of fluvial responses to climate change over the last glacial-interglacial period, and the foundations for future quantitative evaluation of long profile evolution, changes through time in flood magnitude, and changes in storage and flux of sediments. This paper focuses on two issues. First, glacial vs. interglacial period fluvial systems are fundamentally different in terms of channel geometry, depositional style, and patterns of sediment storage. Glacial-period systems were dominated by coarse-grained channel belts (braided channels in Europe, large-wavelength meandering in Texas), and lacked fine-grained flood-plain deposits, whereas Holocene units, especially those of late Holocene age, contain appreciable thicknesses of flood-plain facies. Hence, extreme overbank flooding was not significant during the long glacial period, most flood events were contained within bankfull channel perimeters, and fine sediments were bypassed through the system to marine basins. By contrast, extreme overbank floods have been increasingly important during the relatively short Holocene, and a significant volume of fine sediment is sequestered in flood-plain settings. Second, glacial vs. interglacial systems exhibit different amplitudes and frequencies of fluvial adjustment to climate change. High-amplitude but low-frequency adjustments characterized the long glacial period, with 2-3 extended periods of lateral migration and sediment storage puncuated by episodes of valley incision. Low-amplitude but high-frequency adjustments have been more typical of the short Holocene, when there has been little net valley incision or net changes in sediment storage, but frequent changes in the magnitude and frequency of floods and periods of overbank flooding. This high-frequency signal is absent in landforms and deposits from the glacial period. Glacial vs. interglacial contrasts in process and stratigraphic results are the rule in most large unglaciated fluvial systems. 70-80 percent or more of any 100 kyr glacial-interglacial cycle is characterized by significant ice volume, cooler temperatures, mid-shelf or lower sea-level positions, and cooler-smaller ocean basins. A glacial-period process regime is therefore the norm, and an interglacial regime like that of the late Holocene is relatively unique and non-representative. Large unglaciated midlatitude fluvial systems may be in long-term equilibrium with a glacial-period environment, with long profiles graded to glacial-period sea-level positions, so fluvial systems respond to major changes in climate, discharge regimes, and sediment loads, but they appear to have been relatively insensitive to higher-frequency changes. Short interglacials like the Holocene are, by comparison, periods of abnormally high sea levels and relatively low-amplitude climate changes, but fluvial systems appear to exhibit a greatly increased sensitivity to subtle changes in discharge regimes that produce frequent periods of disequilibrium.

Flood characteristics of urban watersheds in the United States

USGS Publications Warehouse

Sauer, Vernon B.; Thomas, W.O.; Stricker, V.A.; Wilson, K.V.

1983-01-01

A nationwide study of flood magnitude and frequency in urban areas was made for the purpose of reviewing available literature, compiling an urban flood data base, and developing methods of estimating urban floodflow characteristics in ungaged areas. The literature review contains synopses of 128 recent publications related to urban floodflow. A data base of 269 gaged basins in 56 cities and 31 States, including Hawaii, contains a wide variety of topographic and climatic characteristics, land-use variables, indices of urbanization, and flood-frequency estimates. Three sets of regression equations were developed to estimate flood discharges for ungaged sites for recurrence intervals of 2, 5, 10, 25, 50, 100, and 500 years. Two sets of regression equations are based on seven independent parameters and the third is based on three independent parameters. The only difference in the two sets of seven-parameter equations is the use of basin lag time in one and lake and reservoir storage in the other. Of primary importance in these equations is an independent estimate of the equivalent rural discharge for the ungaged basin. The equations adjust the equivalent rural discharge to an urban condition. The primary adjustment factor, or index of urbanization, is the basin development factor, a measure of the extent of development of the drainage system in the basin. This measure includes evaluations of storm drains (sewers), channel improvements, and curb-and-gutter streets. The basin development factor is statistically very significant and offers a simple and effective way of accounting for drainage development and runoff response in urban areas. Percentage of impervious area is also included in the seven-parameter equations as an additional measure of urbanization and apparently accounts for increased runoff volumes. This factor is not highly significant for large floods, which supports the generally held concept that imperviousness is not a dominant factor when soils become more saturated during large storms. Other parameters in the seven-parameter equations include drainage area size, channel slope, rainfall intensity, lake and reservoir storage, and basin lag time. These factors are all statistically significant and provide logical indices of basin conditions. The three-parameter equations include only the three most significant parameters: rural discharge, basin-development factor, and drainage area size. All three sets of regression equations provide unbiased estimates of urban flood frequency. The seven-parameter regression equations without basin lag time have average standard errors of regression varying from ? 37 percent for the 5-year flood to ? 44 percent for the 100-year flood and ? 49 percent for the 500-year flood. The other two sets of regression equations have similar accuracy. Several tests for bias, sensitivity, and hydrologic consistency are included which support the conclusion that the equations are useful throughout the United States. All estimating equations were developed from data collected on drainage basins where temporary in-channel storage, due to highway embankments, was not significant. Consequently, estimates made with these equations do not account for the reducing effect of this temporary detention storage.

Wetland storage to reduce flood damages in the Red River

Treesearch

Steven Shultz

2000-01-01

The restoration of previously drained wetlands to store water was not found to be an economically feasible strategy to reduce flood related damages in two sub-watersheds of the Red River Valley (the Maple River Watershed in North Dakota, and the Wild Rice Watershed of Minnesota). Restoring wetlands, while providing full ecological services, was less feasible, even...

Monitoring groundwater storage change in Mekong Delta using Gravity Recovery and Climate Experiment (GRACE) data

NASA Astrophysics Data System (ADS)

Aierken, A.; Lee, H.; Hossain, F.; Bui, D. D.; Nguyen, L. D.

2016-12-01

The Mekong Delta, home to almost 20 million inhabitants, is considered one of the most important region for Vietnam as it is the agricultural and industrial production base of the nation. However, in recent decades, the region is seriously threatened by variety of environmental hazards, such as floods, saline water intrusion, arsenic contamination, and land subsidence, which raise its vulnerability to sea level rise due to global climate change. All these hazards are related to groundwater depletion, which is the result of dramatically increased over-exploitation. Therefore, monitoring groundwater is critical to sustainable development and most importantly, to people's life in the region. In most countries, groundwater is monitored using well observations. However, because of its spatial and temporal gaps and cost, it is typically difficult to obtain large scale, continuous observations. Since 2002, the Gravity Recovery and Climate Experiment (GRACE) satellite gravimetry mission has delivered freely available Earth's gravity variation data, which can be used to obtain terrestrial water storage (TWS) changes. In this study, the TWS anomalies over the Mekong Delta, which are the integrated sum of anomalies of soil moisture storage (SMS), surface water storage (SWS), canopy water storage (CWS), groundwater storage (GWS), have been obtained using GRACE CSR RL05 data. The leakage error occurred due to GRACE signal processing has been corrected using several different approaches. The groundwater storage anomalies were then derived from TWS anomalies by removing SMS, and CWS anomalies simulated by the four land surface models (NOAH, CLM, VIC and MOSAIC) in the Global Land Data Assimilation System (GLDAS), as well as SWS anomalies estimated using ENVISAT satellite altimetry and MODIS imagery. Then, the optimal GRACE signal restoration method for the Mekong Delta is determined with available in-situ well data. The estimated GWS anomalies revealed continuously decreasing trend, and the flood and drought occurred in 2004 and 2012, respectively. Our study reveals the ability of GRACE to monitor groundwater depletion as well as flood and drought in regional scale.

The experimental flow to the Colorado River delta: Effects on carbon mobilization in a dry watercourse

NASA Astrophysics Data System (ADS)

Bianchi, Thomas S.; Butman, David; Raymond, Peter A.; Ward, Nicholas D.; Kates, Rory J. S.; Flessa, Karl W.; Zamora, Hector; Arellano, Ana R.; Ramirez, Jorge; Rodriguez, Eliana

2017-03-01

Here we report on the effects of an experimental flood on the carbon cycling dynamics in the dry watercourse of the Colorado River in Mexico. We observed post-flood differences in the degree of decay, age, and concentration of dissolved organic carbon (DOC), as well as dissolved CH4 and CO2 concentrations throughout the study site. Our results indicate that this flooded waterway was a limited source of CH4 and CO2 to the atmosphere during the event and that DOC age increased with time of flooding. Based on our findings, we suggest that the interplay between storage and mobilization of carbon and greenhouse gases in arid and semiarid regions is potentially sensitive to changing climate conditions, particularly hydrologic variability. Changes in the radiocarbon age of DOC throughout the flooding event suggest that organic matter (OM) that had been stored for long periods (e.g., millennial) was mobilized by the flooding event along with CO2. The OM residing in the dry riverbed that was mobilized into floodwaters had a signature reflective of degraded vascular plant OM and microbial biomass. Whether this microbial OM was living or dead, our findings support previous work in soils and natural waters showing that microbial OM can remain stable and stored in ecosystems for long time periods. As human appropriation of water resources continues to increase, the episodic drying and rewetting of once natural riverbeds and deltas may fundamentally alter the processing and storage of carbon in such systems.

Detection and attribution of flood change across the United States

NASA Astrophysics Data System (ADS)

Archfield, Stacey

2017-04-01

In the United States, there have a been an increasing number of studies quantifying trends in the annual maximum flood; yet, few studies examine trends in floods that may occur more than once in a given year and even fewer assess trends in floods on rivers that have undergone substantial changes due to urbanization, land-cover change, and agricultural drainage practices. Previous research has shown that, for streamgages having minimal direct human intervention, trends in the peak magnitude, frequency, duration and volume of frequent floods (floods occurring at an average of two events per year relative to a base period) across the United States show large changes; however, few trends are found to be statistically significant. This study extends previous research to provide a comprehensive assessment of flood change across the United States that includes streamgages having experienced confounding alterations to streamflow (urbanization, storage, and land-cover changes) that provides a comprehensive assessment of flood change. Attribution of these changes is also explored.

Dynamic Water Storage during Flash Flood Events in the Mountainous Area of Rio de Janeiro/Brazil - Case study: Piabanha River Basin

NASA Astrophysics Data System (ADS)

Araujo, L.; Silva, F. P. D.; Moreira, D. M.; Vásquez P, I. L.; Justi da Silva, M. G. A.; Fernandes, N.; Rotunno Filho, O. C.

2017-12-01

Flash floods are characterized by a rapid rise in water levels, high flow rates and large amounts of debris. Several factors have relevance to the occurrence of these phenomena, including high precipitation rates, terrain slope, soil saturation degree, vegetation cover, soil type, among others. In general, the greater the precipitation intensity, the more likely is the occurrence of a significant increase in flow rate. Particularly on steep and rocky plains or heavily urbanized areas, relatively small rain rates can trigger a flash flood event. In addition, high rain rates in short time intervals can temporarily saturate the surface soil layer acting as waterproofing and favoring the occurrence of greater runoff rates due to non-infiltration of rainwater into the soil. Thus, although precipitation is considered the most important factor for flooding, the interaction between rainfall and the soil can sometimes be of greater importance. In this context, this work investigates the dynamic storage of water associated with flash flood events for Quitandinha river watershed, a tributary of Piabanha river, occurred between 2013 and 2014, by means of water balance analyses applied to three watersheds of varying magnitudes (9.25 km², 260 km² and 429 km²) along the rainy season under different time steps (hourly and daily) using remotely sensed and observational precipitation data. The research work is driven by the hypothesis of a hydrologically active bedrock layer, as the watershed is located in a humid region, having intemperate (fractured) rock layer, just below a shallow soil layer, in the higher part of the basin where steep slopes prevail. The results showed a delay of the variation of the dynamic storage in relation to rainfall peaks and water levels. Such behavior indicates that the surface soil layer, which is not very thick in the region, becomes rapidly saturated along rainfall events. Subsequently, the water infiltrates into the rocky layer and the water storage in the fractured bedrock assumes significant role due to its corresponding release to streams as storm flows.

49 CFR 1220.2 - Protection and storage of records.

Code of Federal Regulations, 2010 CFR

2010-10-01

... § 1220.2 Protection and storage of records. (a) The company shall protect records subject to this part from fires, floods, and other hazards, and safeguard the records from unnecessary exposure to deterioration from excessive humidity, dryness, or lack of ventilation. (b) The company shall notify the Board...

Hydrological impacts on methane and carbon dioxide fluxes of hyperseasonal Cerrado forests of the Northern Pantanal, Mato Grosso, Brazil.

NASA Astrophysics Data System (ADS)

Vourlitis, G. L.; Dalmagro, H. J.; Arruda, P. H. Z. D.; Lathuilliere, M. J.; Borges Pinto, O.; Couto, E. G.; Nogueira, J. D. S.; Johnson, M. S.

2016-12-01

Wetlands have a great potential for carbon (C) storage because frequent waterlogging can inhibit microbial respiration. However, waterlogging can also promote methane (CH4) production, which reduces ecosystem C sequestration. Unfortunately, the C storage dynamics of seasonally flooded (hyperseasonal) tropical forests are poorly understood even though the large C stocks, warm temperature, and prolonged flooding have the potential to cause high rates of CO2 storage and CH4 emission. Thus, the aim of this study was to provide a continuous ecosystem-level quantification of CO2 and CH4 fluxes and carbon balance for a hyperseasonal forest in the Brazilian Pantanal using eddy covariance. Trace gas fluxes were measured using an eddy covariance system installed on a 28 m tall tower. The study area was chosen because it represents approximately 12% of the total area of the Pantanal, which consists of seasonal floodplains with an annual flood pulse that results from an intense rainy season (October to April) that is followed by an intense dry season (May to September). The measurements were performed over two flood cycles and an intervening drought period between the years 2014 and 2015. In 2015 the study area was flooded for 190 days, which was 22 days longer than in 2014. Mean (± SD) rates of CH4 flux during the 2014 and 2015 flooded period were 0.091 ± 0.04 µmol m-2 s-1 and 0.118 ± 0.04 µmol m-2 s-1, respectively, and almost zero (0.001 ± 0.0001 µmol m-2 s-1) during 2015 dry season. In contrast, mean CO2 flux rates during the flooded period were -1.58 and -1.50 µmol m-2 s-1 for 2014 and 2015, respectively, showing the net ecosystem CO2 uptake, while during the dry season, the forest was a net source of CO2 to the atmosphere of on average 0.73 µmol m-2 s-1. Total wet season carbon balance (CO2 + CH4) was virtually identical in 2014 and 2015 (ca. -255 gC m-2) even though the 2015 flood period was longer; however, the ecosystem lost 139 gC m-2 during the dry period of 2015. These data indicate that hyperseasonal forests of the Pantanal, and presumably other seasonally flooded tropical forests, are potentially large sources of CH4, but overall large C sinks.

Changes in bottom-surface elevations in three reservoirs on the lower Susquehanna River, Pennsylvania and Maryland, following the January 1996 flood; implications for nutrient and sediment loads to Chesapeake Bay

USGS Publications Warehouse

Langland, Michael J.; Hainly, Robert A.

1997-01-01

The Susquehanna River drains about 27,510 square miles in New York, Pennsylvania, and Maryland, contributes nearly 50 percent of the freshwater discharge to the Chesapeake Bay, and contributes nearly 66 percent of the annual nitrogen load, 40 percent of the phosphorus load, and 25 percent of the suspended-sediment load from non-tidal parts of the Bay during a year of average streamflow. A reservoir system formed by three hydroelectric dams on the lower Susquehanna River is currently trapping a major part of the phosphorus and suspended-sediment loads from the basin and, to a lesser extent, the nitrogen loads.In the summer of 1996, the U. S. Geological Survey collected bathymetric data along 64 cross sections and 40 bottom-sediment samples along 14 selected cross sections in the lower Susquehanna River reservoir system to determine the remaining sediment-storage capacity, refine the current estimate of when the system may reach sediment-storage capacity, document changes in the reservoir system after the January 1996 flood, and determine the remaining nutrient mass in Conowingo Reservoir. Results from the 1996 survey indicate an estimated total of 14,800,000 tons of sediment were scoured from the reservoir system from 1993 (date of previous bathymetric survey) through 1996. This includes the net sediment change of 4,700,000 tons based on volume change in the reservoir system computed from the 1993 and 1996 surveys, the 6,900,000 tons of sediment deposited from 1993 through 1996, and the 3,200,000 tons of sediment transported into the reservoir system during the January 1996 flood. The January 1996 flood, which exceeded a 100-year recurrence interval, scoured about the same amount of sediment that normally would be deposited in the reservoir system during a 4- to 6-year period.Concentrations of total nitrogen in bottom sediments in the Conowingo Reservoir ranged from 1,500 to 6,900 mg/kg (milligrams per kilogram); 75 percent of the concentrations were between 3,000 and 5,000 mg/kg. About 96 percent of the concentrations of total nitrogen consisted of organic nitrogen. Concentrations of total phosphorus in bottom sediments ranged from 286 to 1,390 mg/kg. About 84 percent of the concentrations of total phosphorus were comprised of inorganic phosphorus. The ratio of concentrations of plant-available phosphorus to concentrations of total phosphorus ranged from 0.6 to 3.5 percent; ratios generally decreased in a downstream direction.About 29,000 acre-feet, or 42,000,000 tons, of sediment can be deposited before Conowingo Reservoir reaches sediment-storage capacity. Assuming the average annual sediment-deposition rate remains unchanged and no scour occurs due to floods, the reservoir system could reach sediment-storage capacity in about 17 years. The reservoir system currently is trapping about 2 percent of the nitrogen, 45 percent of the phosphorus, and 70 percent of the suspended sediment transported by the river to the upper Chesapeake Bay. Once the reservoir reaches sediment-storage capacity, an estimated 250-percent increase in the current annual loads of suspended sediment, a 2-percent increase in the current annual loads of total nitrogen, and a 70-percent increase in the current annual loads of total phosphorus from the Susquehanna River to Chesapeake Bay can be expected. If the goal of a 40-percent reduction in controllable phosphorus load from the Susquehanna River Basin is met before the reservoirs reach sediment-storage capacity, the 40-percent reduction goal will probably be exceeded when the reservoir system reaches sediment-storage capacity.

Development of regional skews for selected flood durations for the Central Valley Region, California, based on data through water year 2008

USGS Publications Warehouse

Lamontagne, Jonathan R.; Stedinger, Jery R.; Berenbrock, Charles; Veilleux, Andrea G.; Ferris, Justin C.; Knifong, Donna L.

2012-01-01

Flood-frequency information is important in the Central Valley region of California because of the high risk of catastrophic flooding. Most traditional flood-frequency studies focus on peak flows, but for the assessment of the adequacy of reservoirs, levees, other flood control structures, sustained flood flow (flood duration) frequency data are needed. This study focuses on rainfall or rain-on-snow floods, rather than the annual maximum, because rain events produce the largest floods in the region. A key to estimating flood-duration frequency is determining the regional skew for such data. Of the 50 sites used in this study to determine regional skew, 28 sites were considered to have little to no significant regulated flows, and for the 22 sites considered significantly regulated, unregulated daily flow data were synthesized by using reservoir storage changes and diversion records. The unregulated, annual maximum rainfall flood flows for selected durations (1-day, 3-day, 7-day, 15-day, and 30-day) for all 50 sites were furnished by the U.S. Army Corps of Engineers. Station skew was determined by using the expected moments algorithm program for fitting the Pearson Type 3 flood-frequency distribution to the logarithms of annual flood-duration data. Bayesian generalized least squares regression procedures used in earlier studies were modified to address problems caused by large cross correlations among concurrent rainfall floods in California and to address the extensive censoring of low outliers at some sites, by using the new expected moments algorithm for fitting the LP3 distribution to rainfall flood-duration data. To properly account for these problems and to develop suitable regional-skew regression models and regression diagnostics, a combination of ordinary least squares, weighted least squares, and Bayesian generalized least squares regressions were adopted. This new methodology determined that a nonlinear model relating regional skew to mean basin elevation was the best model for each flood duration. The regional-skew values ranged from -0.74 for a flood duration of 1-day and a mean basin elevation less than 2,500 feet to values near 0 for a flood duration of 7-days and a mean basin elevation greater than 4,500 feet. This relation between skew and elevation reflects the interaction of snow and rain, which increases with increased elevation. The regional skews are more accurate, and the mean squared errors are less than in the Interagency Advisory Committee on Water Data's National skew map of Bulletin 17B.

Conjunctively optimizing flash flood control and water quality in urban water reservoirs by model predictive control and dynamic emulation

NASA Astrophysics Data System (ADS)

Galelli, Stefano; Goedbloed, Albert; Schmitter, Petra; Castelletti, Andrea

2014-05-01

Urban water reservoirs are a viable adaptation option to account for increasing drinking water demand of urbanized areas as they allow storage and re-use of water that is normally lost. In addition, the direct availability of freshwater reduces pumping costs and diversifies the portfolios of drinking water supply. Yet, these benefits have an associated twofold cost. Firstly, the presence of large, impervious areas increases the hydraulic efficiency of urban catchments, with short time of concentration, increased runoff rates, losses of infiltration and baseflow, and higher risk of flash floods. Secondly, the high concentration of nutrients and sediments characterizing urban discharges is likely to cause water quality problems. In this study we propose a new control scheme combining Model Predictive Control (MPC), hydro-meteorological forecasts and dynamic model emulation to design real-time operating policies that conjunctively optimize water quantity and quality targets. The main advantage of this scheme stands in its capability of exploiting real-time hydro-meteorological forecasts, which are crucial in such fast-varying systems. In addition, the reduced computational requests of the MPC scheme allows coupling it with dynamic emulators of water quality processes. The approach is demonstrated on Marina Reservoir, a multi-purpose reservoir located in the heart of Singapore and characterized by a large, highly urbanized catchment with a short (i.e. approximately one hour) time of concentration. Results show that the MPC scheme, coupled with a water quality emulator, provides a good compromise between different operating objectives, namely flood risk reduction, drinking water supply and salinity control. Finally, the scheme is used to assess the effect of source control measures (e.g. green roofs) aimed at restoring the natural hydrological regime of Marina Reservoir catchment.

Causal mechanisms of soil organic matter decomposition: Deconstructing salinity and flooding impacts in coastal wetlands

USGS Publications Warehouse

Stagg, Camille L.; Schoolmaster, Donald; Krauss, Ken W.; Cormier, Nicole; Conner, William H.

2017-01-01

Coastal wetlands significantly contribute to global carbon storage potential. Sea-level rise and other climate change-induced disturbances threaten coastal wetland sustainability and carbon storage capacity. It is critical that we understand the mechanisms controlling wetland carbon loss so that we can predict and manage these resources in anticipation of climate change. However, our current understanding of the mechanisms that control soil organic matter decomposition, in particular the impacts of elevated salinity, are limited, and literature reports are contradictory. In an attempt to improve our understanding of these complex processes, we measured root and rhizome decomposition and developed a causal model to identify and quantify the mechanisms that influence soil organic matter decomposition in coastal wetlands that are impacted by sea-level rise. We identified three causal pathways: 1) a direct pathway representing the effects of flooding on soil moisture, 2) a direct pathway representing the effects of salinity on decomposer microbial communities and soil biogeochemistry, and 3) an indirect pathway representing the effects of salinity on litter quality through changes in plant community composition over time. We used this model to test the effects of alternate scenarios on the response of tidal freshwater forested wetlands and oligohaline marshes to short- and long-term climate-induced disturbances of flooding and salinity. In tidal freshwater forested wetlands, the model predicted less decomposition in response to drought, hurricane salinity pulsing, and long-term sea-level rise. In contrast, in the oligohaline marsh, the model predicted no change in response to sea-level rise, and increased decomposition following a drought or a hurricane salinity pulse. Our results show that it is critical to consider the temporal scale of disturbance and the magnitude of exposure when assessing the effects of salinity intrusion on carbon mineralization in coastal wetlands. Here we identify three causal mechanisms that can reconcile disparities between long-term and short-term salinity impacts on organic matter decomposition.

Causal mechanisms of soil organic matter decomposition: deconstructing salinity and flooding impacts in coastal wetlands.

PubMed

Stagg, Camille L; Schoolmaster, Donald R; Krauss, Ken W; Cormier, Nicole; Conner, William H

2017-08-01

Coastal wetlands significantly contribute to global carbon storage potential. Sea-level rise and other climate-change-induced disturbances threaten coastal wetland sustainability and carbon storage capacity. It is critical that we understand the mechanisms controlling wetland carbon loss so that we can predict and manage these resources in anticipation of climate change. However, our current understanding of the mechanisms that control soil organic matter decomposition, in particular the impacts of elevated salinity, are limited, and literature reports are contradictory. In an attempt to improve our understanding of these complex processes, we measured root and rhizome decomposition and developed a causal model to identify and quantify the mechanisms that influence soil organic matter decomposition in coastal wetlands that are impacted by sea-level rise. We identified three causal pathways: (1) a direct pathway representing the effects of flooding on soil moisture, (2) a direct pathway representing the effects of salinity on decomposer microbial communities and soil biogeochemistry, and (3) an indirect pathway representing the effects of salinity on litter quality through changes in plant community composition over time. We used this model to test the effects of alternate scenarios on the response of tidal freshwater forested wetlands and oligohaline marshes to short- and long-term climate-induced disturbances of flooding and salinity. In tidal freshwater forested wetlands, the model predicted less decomposition in response to drought, hurricane salinity pulsing, and long-term sea-level rise. In contrast, in the oligohaline marsh, the model predicted no change in response to drought and sea-level rise, and increased decomposition following a hurricane salinity pulse. Our results show that it is critical to consider the temporal scale of disturbance and the magnitude of exposure when assessing the effects of salinity intrusion on carbon mineralization in coastal wetlands. Here, we identify three causal mechanisms that can reconcile disparities between long-term and short-term salinity impacts on organic matter decomposition. © 2017 by the Ecological Society of America.

A Framework for Flood Risk Analysis and Benefit Assessment of Flood Control Measures in Urban Areas

PubMed Central

Li, Chaochao; Cheng, Xiaotao; Li, Na; Du, Xiaohe; Yu, Qian; Kan, Guangyuan

2016-01-01

Flood risk analysis is more complex in urban areas than that in rural areas because of their closely packed buildings, different kinds of land uses, and large number of flood control works and drainage systems. The purpose of this paper is to propose a practical framework for flood risk analysis and benefit assessment of flood control measures in urban areas. Based on the concept of disaster risk triangle (hazard, vulnerability and exposure), a comprehensive analysis method and a general procedure were proposed for urban flood risk analysis. Urban Flood Simulation Model (UFSM) and Urban Flood Damage Assessment Model (UFDAM) were integrated to estimate the flood risk in the Pudong flood protection area (Shanghai, China). S-shaped functions were adopted to represent flood return period and damage (R-D) curves. The study results show that flood control works could significantly reduce the flood risk within the 66-year flood return period and the flood risk was reduced by 15.59%. However, the flood risk was only reduced by 7.06% when the flood return period exceeded 66-years. Hence, it is difficult to meet the increasing demands for flood control solely relying on structural measures. The R-D function is suitable to describe the changes of flood control capacity. This frame work can assess the flood risk reduction due to flood control measures, and provide crucial information for strategy development and planning adaptation. PMID:27527202

Balancing-out floods and droughts: Opportunities to utilize floodwater harvesting and groundwater storage for agricultural development in Thailand

NASA Astrophysics Data System (ADS)

Pavelic, Paul; Srisuk, Kriengsak; Saraphirom, Phayom; Nadee, Suwanchai; Pholkern, Kewaree; Chusanathas, Sumrit; Munyou, Sitisak; Tangsutthinon, Theerasak; Intarasut, Teerawash; Smakhtin, Vladimir

2012-11-01

SummaryThailand's naturally high seasonal endowment of water resources brings with it the regularly experienced problems associated with floods during the wet season and droughts during the dry season. Downstream-focused engineering solutions that address flooding are vital, but do not necessarily capture the potential for basin-scale improvements to water security, food production and livelihood enhancement. Managed aquifer recharge, typically applied to annual harvesting of wet season flows in dry climates, can also be applied to capture, store and recover episodic extreme flood events in humid environments. In the Chao Phraya River Basin it is estimated that surplus flows recorded downstream above a critical threshold could be harvested and recharged within the shallow alluvial aquifers in a distributed manner upstream of flood prone areas without significantly impacting existing large-medium storages or the Gulf and deltaic ecosystems. Capturing peak flows approximately 1 year in four by dedicating around 200 km2 of land to groundwater recharge would reduce the magnitude of flooding and socio-economic impacts and generate around USD 250 M/year in export earnings for smallholder rainfed farmers through dry season cash cropping without unduly compromising the demands of existing water users. It is proposed that farmers in upstream riparian zones be co-opted as flood harvesters and thus contribute to improved floodwater management through simple water management technologies that enable agricultural lands to be put to higher productive use. Local-scale site suitability and technical performance assessments along with revised governance structures would be required. It is expected that such an approach would also be applicable to other coastal-discharging basins in Thailand and potentially throughout the Asia region.

Water Cycle Implications of Agriculture and Flood Control Infrastructure in the San Francisco Bay-Delta System

NASA Astrophysics Data System (ADS)

MacVean, L. J.; Thompson, S. E.; Sivapalan, M.; Hutton, P.

2016-12-01

California's Sacramento-San Joaquin Delta sits at the intersection of vast agricultural and population centers, and supplies fresh water for the diverse and often competing needs of ecosystems, farmers, and millions of Californians. In this study, we address the question of how flows into and out of the Delta have evolved in response to human intervention since 1850 in order to augment the scientific foundation of management decisions. In particular, we have developed a numerical model to quantify Delta outflows over the last 165 years, through which we explore the implications of the conversion of native vegetation to agricultural crops and the construction of flood control infrastructure. Our model domain encompasses the watersheds tributary to the San Francisco Bay-Delta system, and simulates the dynamic components of water usage through vegetative uptake and evapotranspiration, groundwater recharge, flood conveyance, and water exports at incremental levels of development from 1850 to the present. The model is run using historical climatological forcing; the climate and the effects of development on the Delta's watersheds are allowed to co-evolve. After verification that the dominant processes are captured in the numerics, the results illustrate the interactions between soil water storage, flood water stored behind levees, and consumption of water through ET and groundwater recharge, and their effects on the inflows to the San Francisco Bay estuary. Our study provides a picture of the changes in magnitude and temporal distribution of freshwater flows brought about by both intentional and unintentional consequences of the development of California's Central Valley.

Sources of fine-grained sediment in the Linganore Creek watershed, Frederick and Carroll Counties, Maryland, 2008-10

USGS Publications Warehouse

Gellis, Allen C.; Noe, Gregory B.; Clune, John W.; Myers, Michael K.; Hupp, Cliff R.; Schenk, Edward R.; Schwarz, Gregory E.

2015-01-01

Management implications of this study indicate that both agriculture and streambanks are important sources of sediment in Linganore Creek where the delivery of agriculture sediment was 4 percent and the delivery of streambank sediment was 44 percent. Fourth order streambanks, on average, had the highest rates of bank erosion. Combining the sediment fingerprinting and sediment budget results indicates that 96 percent of the eroded fine-grained sediment from agriculture went into storage. Flood plains and ponds are effective storage sites of sediment in the Linganore Creek watershed. Flood plains stored 8 percent of all eroded sediment with 4th and 5th order flood plains, on average, storing the most sediment. Small ponds in the Linganore Creek watershed, which drained 16 percent of the total watershed area, stored 15 percent of all eroded sediment. Channel beds were relatively stable with the greatest erosion generally occurring in 4th and 5th order streams.

Storage in California’s reservoirs and snowpack in this time of drought

USGS Publications Warehouse

Dettinger, Michael; Anderson, Michael L.

2015-01-01

The San Francisco Bay and Sacramento–San Joaquin Delta (Delta) are the recipients of inflows from a watershed that spans much of California and that has ties to nearly the entire state. Historically, California has buffered its water supplies and flood risks both within—and beyond—the Delta’s catchment by developing many reservoirs, large and small, high and low. Most of these reservoirs carry water from wet winter seasons—when water demands are low and flood risks are high—to dry, warm seasons (and years) when demands are high and little precipitation falls. Many reservoirs are also used to catch and delay (or spread in time) flood flows that otherwise might cause damage to communities and floodplains. This essay describes the status of surface-water and snowpack storage conditions in California in spring 2015, providing context for better understanding where the state’s water stores stand as we enter summer 2015.

Residence times and mixing of water in river banks: implications for recharge and groundwater - surface water exchange

NASA Astrophysics Data System (ADS)

Unland, N. P.; Cartwright, I.; Cendón, D. I.; Chisari, R.

2014-02-01

The residence time of groundwater within 50 m of the Tambo River, South East Australia, has been estimated through the combined use of 3H and 14C. Groundwater residence times increase towards the Tambo River which implies a gaining river system and not increasing bank storage with proximity to the Tambo River. Major ion concentrations and δ2H and δ18O values of bank water also indicate that bank infiltration does not significantly impact groundwater chemistry under baseflow and post-flood conditions, suggesting that the gaining nature of the river may be driving the return of bank storage water back into the Tambo River within days of peak flood conditions. The covariance between 3H and 14C indicates the leakage and mixing between old (~17 200 yr) groundwater from a semi-confined aquifer and younger groundwater (<100 yr) near the river where confining layers are less prevalent. The presence of this semi-confined aquifer has also been used to help explain the absence of bank storage, as rapid pressure propagation into the semi-confined aquifer during flooding will minimise bank infiltration. This study illustrates the complex nature of river groundwater interactions and the potential downfall in assuming simple or idealised conditions when conducting hydrogeological studies.

Increasing precipitation volatility in twenty-first-century California

NASA Astrophysics Data System (ADS)

Swain, Daniel L.; Langenbrunner, Baird; Neelin, J. David; Hall, Alex

2018-05-01

Mediterranean climate regimes are particularly susceptible to rapid shifts between drought and flood—of which, California's rapid transition from record multi-year dryness between 2012 and 2016 to extreme wetness during the 2016-2017 winter provides a dramatic example. Projected future changes in such dry-to-wet events, however, remain inadequately quantified, which we investigate here using the Community Earth System Model Large Ensemble of climate model simulations. Anthropogenic forcing is found to yield large twenty-first-century increases in the frequency of wet extremes, including a more than threefold increase in sub-seasonal events comparable to California's `Great Flood of 1862'. Smaller but statistically robust increases in dry extremes are also apparent. As a consequence, a 25% to 100% increase in extreme dry-to-wet precipitation events is projected, despite only modest changes in mean precipitation. Such hydrological cycle intensification would seriously challenge California's existing water storage, conveyance and flood control infrastructure.

Floods, floodplains, delta plains — A satellite imaging approach

NASA Astrophysics Data System (ADS)

Syvitski, James P. M.; Overeem, Irina; Brakenridge, G. Robert; Hannon, Mark

2012-08-01

Thirty-three lowland floodplains and their associated delta plains are characterized with data from three remote sensing systems (AMSR-E, SRTM and MODIS). These data provide new quantitative information to characterize Late Quaternary floodplain landscapes and their penchant for flooding over the last decade. Daily proxy records for discharge since 2002 and for each of the 33 river systems can be derived with novel Advanced Microwave Scanning Radiometer (AMSR-E) methods. A descriptive framework based on analysis of Shuttle Radar Topography Mission (SRTM) data is used to capture the major landscape-scale floodplain elements or zones: 1) container valleys with their long and narrow pathways of largely sediment transit and bypass, 2) floodplain depressions that act as loci for frequent flooding and sediment storage, 3) zones of nodal avulsions common to many continental scale rivers, and often located seaward of container valleys, and 4) coastal floodplains and delta plains that offer both sediment bypass and storage but under the influence of marine processes. The SRTM data allow mapping of smaller-scale architectural elements in unprecedented systematic manner. Floodplain depressions were found to play a major role, which may largely be overlooked in conceptual floodplain models. Lastly, MODIS data (independently and combined with AMSR-E) allows the tracking of flood hydrographs and pathways and sedimentation patterns on a near-daily timescale worldwide. These remote-sensing data show that 85% of the studied major river systems experienced extensive flooding in the last decade. A new quantitative paradigm of floodplain processes, honoring the frequency and extent of floods, can be develop by careful analysis of these new remotely sensed data.

Instrumentation for detailed bridge-scour measurements

USGS Publications Warehouse

Landers, Mark N.; Mueller, David S.; Trent, Roy E.; ,

1993-01-01

A portable instrumentation system is being developed to obtain channel bathymetry during floods for detailed bridge-scour measurements. Portable scour measuring systems have four components: sounding instrument, horizontal positioning instrument, deployment mechanisms, and data storage device. The sounding instrument will be a digital fathometer. Horizontal position will be measured using a range-azimuth based hydrographic survey system. The deployment mechanism designed for this system is a remote-controlled boat using a small waterplane area, twin-hull design. An on-board computer and radio will monitor the vessel instrumentation, record measured data, and telemeter data to shore.

Use of real time control modelling on the urban sewage system of Nancy.

PubMed

Zug, M; Faure, D; De Belly, B; Phan, L

2001-01-01

Since 1991, European Legislation on the urban treatment of wastewater requires local authorities to take into account the treatment of polluted water transported by the sewerage system and this during dry and wet weather conditions. In the seventies, the urban Community of Grand Nancy constructed storage tanks in its sewerage system in order to prevent flooding and wish today to use them to reduce and control the pollution discharges into the receiving water. This action is a part of a European LIFE project 1996-2000. The main aim of this project was to assess the effectiveness of reducing pollution of one particular retention basin, the 12,000 m3 Gentilly tank. This one has two operating modes: protection against floods during heavy rain and reduction of pollutant overflows during lighter rain. To assess its effect on the pollutant discharge, the HYDROWORKS DM software and its Real Time Control Module have been used, calibrated and validated. As this study is still in progress, this paper describes the studied site and the modelling results under different weather conditions and shows that the mathematical model can be used to simulate the operation of the catchment area and its associated sewerage system realistically.

Use of frequency analysis and the extended streamflow prediction procedure to estimate evacuation dates for the joint-use pool of Pueblo Reservoir, Colorado

USGS Publications Warehouse

Kuhn, Gerhard; Nickless, R.C.

1994-01-01

Part of the storage space of Pueblo Reservoir consists of a 65,950 acre-foot joint-use pool (JUP) that can be used to provide additional conservation capacity from November 1 to April 14; however, the JUP must be evacuated by April 15 and used only for flood-control capacity until November 1. A study was completed to determine if the JUP possibly could be used for conservation storage for any number of days from April 15 through May 14 under certain hydrologic conditions. The methods of the study were: (1) Frequency analysis of recorded daily mean discharge data for streamflow-gaging stations upstream and downstream from Pueblo Reservoir, and (2) Implementation of the extended streamflow prediction (ESP) procedure for the Arkansas River basin upstream from the reservoir. The frequency analyses enabled estimation of daily discharges at selected exceedance probabilities (EP's), including the 0.01 EP that was used in design of the flood- storage capacity of Pueblo Reservoir. The ESP procedure enabled probabilistic forecasts of inflow volume to the reservoir for April 15 through May 14. Daily discharges derived from the frequency analyses were routed through Pueblo Reservoir to estimate evacuation dates of the JUP for different reservoir inflow volumes; the estimates indicated a relation between the inflow volume and the JUP evacuation date. To apply the study results, only a ESP forecast of the April 15-May 14 reservoir inflow volume is needed. Study results indicate the JUP possibly could be used as late as May 5 depending on the forecast inflow volume.

Real-time updating of the flood frequency distribution through data assimilation

NASA Astrophysics Data System (ADS)

Aguilar, Cristina; Montanari, Alberto; Polo, María-José

2017-07-01

We explore the memory properties of catchments for predicting the likelihood of floods based on observations of average flows in pre-flood seasons. Our approach assumes that flood formation is driven by the superimposition of short- and long-term perturbations. The former is given by the short-term meteorological forcing leading to infiltration and/or saturation excess, while the latter is originated by higher-than-usual storage in the catchment. To exploit the above sensitivity to long-term perturbations, a meta-Gaussian model and a data assimilation approach are implemented for updating the flood frequency distribution a season in advance. Accordingly, the peak flow in the flood season is predicted in probabilistic terms by exploiting its dependence on the average flow in the antecedent seasons. We focus on the Po River at Pontelagoscuro and the Danube River at Bratislava. We found that the shape of the flood frequency distribution is noticeably impacted by higher-than-usual flows occurring up to several months earlier. The proposed technique may allow one to reduce the uncertainty associated with the estimation of flood frequency.

High-Performance Integrated Control of water quality and quantity in urban water reservoirs

NASA Astrophysics Data System (ADS)

Galelli, S.; Castelletti, A.; Goedbloed, A.

2015-11-01

This paper contributes a novel High-Performance Integrated Control framework to support the real-time operation of urban water supply storages affected by water quality problems. We use a 3-D, high-fidelity simulation model to predict the main water quality dynamics and inform a real-time controller based on Model Predictive Control. The integration of the simulation model into the control scheme is performed by a model reduction process that identifies a low-order, dynamic emulator running 4 orders of magnitude faster. The model reduction, which relies on a semiautomatic procedural approach integrating time series clustering and variable selection algorithms, generates a compact and physically meaningful emulator that can be coupled with the controller. The framework is used to design the hourly operation of Marina Reservoir, a 3.2 Mm3 storm-water-fed reservoir located in the center of Singapore, operated for drinking water supply and flood control. Because of its recent formation from a former estuary, the reservoir suffers from high salinity levels, whose behavior is modeled with Delft3D-FLOW. Results show that our control framework reduces the minimum salinity levels by nearly 40% and cuts the average annual deficit of drinking water supply by about 2 times the active storage of the reservoir (about 4% of the total annual demand).

Corps Water Management System (CWMS) Decision Support Modeling and Integration Use in the June 2007 Texas Floods

NASA Astrophysics Data System (ADS)

Charley, W. J.; Luna, M.

2007-12-01

The U.S. Army Corps of Engineers Corps Water Management System (CWMS) is a comprehensive data acquisition and hydrologic modeling system for short-term decision support of water control operations in real time. It encompasses data collection, validation and transformation, data storage, visualization, real time model simulation for decision-making support, and data dissemination. CWMS uses an Oracle database and Sun Solaris workstations for data processes, storage and the execution of models, with a client application (the Control and Visualization Interface, or CAVI) that can run on a Windows PC. CWMS was used by the Lower Colorado River Authority (LCRA) to make hydrologic forecasts of flows on the Lower Colorado River and operate reservoirs during the June 2007 event in Texas. The LCRA receives real-time observed gridded spatial rainfall data from OneRain, Inc. that which is a result of adjusting NexRad rainfall data with precipitation gages. This data is used, along with future precipitation estimates, for hydrologic forecasting by the rainfall-runoff modeling program HEC-HMS. Forecasted flows from HEC-HMS and combined with observed flows and reservoir information to simulate LCRA's reservoir operations and help engineers make release decisions based on the results. The river hydraulics program, HEC-RAS, computes river stages and water surface profiles for the computed flow. An inundation boundary and depth map of water in the flood plain can be calculated from the HEC-RAS results using ArcInfo. By varying future precipitation and releases, engineers can evaluate different "What if?" scenarios. What was described as an "extraordinary cluster of thunderstorms" that stalled over Burnet and Llano counties in Texas on June 27, 2007, dropped 17 to 19 inches of rainfall over a 6-hour period. The storm was classified over a 500-year event and the resulting flow over some of the smaller tributaries as a 100-year or better. CWMS was used by LCRA for flood forecasting and reservoir operations. The models accurately forecasting the flows and allowed engineers to determine that only four floodgates needed to be opened for Mansfield dam, in the Chain of Highland lakes. CWMS also forecasted the peak of the flood well before it happened. Smaller rain storms continued for a period of weeks and CWMS was used throughout the event calculating lake levels, closing of gates along with a hydro-generation schedule.

Monitoring Reservoir Storage in South Asia from Satellite Remote Sensing

NASA Astrophysics Data System (ADS)

Zhang, S.; Gao, H.; Naz, B.

2013-12-01

Realtime reservoir storage information is essential for accurate flood monitoring and prediction in South Asia, where the fatality rate (by area) due to floods is among the highest in the world. However, South Asia is dominated by international river basins where communications among neighboring countries about reservoir storage and management are extremely limited. In this study, we use a suite of NASA satellite observations to achieve high quality estimation of reservoir storage and storage variations at near realtime in South Asia. The monitoring approach employs vegetation indices from the Moderate Resolution Imaging Spectroradiometer (MODIS) 16-day 250 m MOD13Q1 product and the surface elevation data from the Geoscience Laser Altimeter System (GLAS) on board the Ice, Cloud and land Elevation Satellite (ICESat). This approach contains four steps: 1) identifying the reservoirs with ICESat GLAS overpasses and extracting the elevation data for these locations; 2) using the K-means method for water classification from MODIS andapplying a novel post-classification algorithm to enhance water area estimation accuracy; 3) deriving the relationship between the MODIS water surface area and the ICESat elevation; and 4) estimating the storage of reservoirs over time based on the elevation-area relationship and the MODIS water area time series. For evaluation purposes, we compared the satellite-based reservoir storage with gauge observations for 16 reservoirs in South Asia. The storage estimates were highly correlated with observations (R = 0.92 to 0.98), with values for the normalized root mean square error (NRMSE) ranging from 8.7% to 25.2%. Using this approach, storage and storage variations were estimated for 16 South Asia reservoirs from 2000 to 2012.

30 CFR 762.5 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... dunes, severe wind or soil erosion, frequent flooding, avalanches and areas of unstable geology...-handling, preparation, extraction or storage facilities, and other capital-intensive activities. Costs of...

30 CFR 762.5 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... dunes, severe wind or soil erosion, frequent flooding, avalanches and areas of unstable geology...-handling, preparation, extraction or storage facilities, and other capital-intensive activities. Costs of...

30 CFR 762.5 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... dunes, severe wind or soil erosion, frequent flooding, avalanches and areas of unstable geology...-handling, preparation, extraction or storage facilities, and other capital-intensive activities. Costs of...

33 CFR 203.50 - Nonstructural alternatives to rehabilitation of flood control works.

Code of Federal Regulations, 2014 CFR

2014-07-01

... DISASTER PROCEDURES Rehabilitation Assistance for Flood Control Works Damaged by Flood or Coastal Storm... rehabilitation, repair, or restoration of flood control works damaged by floods or coastal storms. (b) Policy. (1...

75 FR 44982 - Arkansas Valley Conduit (AVC) and Long-Term Excess Capacity Master Contract, Fryingpan-Arkansas...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-30

... Reservoir due to AVC and Excess Capacity Master Contract operations and potential contributions to flooding... Southeastern for storage of non-Fry-Ark Project water in Pueblo Reservoir, a feature of the Fry-Ark Project... storage in Pueblo Reservoir for entities within its boundaries in the Upper Arkansas basin, Lower Arkansas...

Effects of Flood Control Strategies on Flood Resilience Under Sociohydrological Disturbances

NASA Astrophysics Data System (ADS)

Sung, Kyungmin; Jeong, Hanseok; Sangwan, Nikhil; Yu, David J.

2018-04-01

A community capacity to cope with flood hazards, or community flood resilience, emerges from the interplay of hydrological and social processes. This interplay can be significantly influenced by the flood control strategy adopted by a society, i.e., how a society sets its desired flood protection level and strives to achieve this goal. And this interplay can be further complicated by rising land-sea level differences, seasonal water level fluctuations, and economic change. But not much research has been done on how various forms of flood control strategies affect human-flood interactions under these disturbances and therefore flood resilience in the long run. The current study is an effort to address these issues by developing a conceptual model of human-flood interaction mediated by flood control strategies. Our model extends the existing model of Yu et al. (2017), who investigated the flood resilience of a community-based flood protection system in coastal Bangladesh. The major extensions made in this study are inclusions of various forms of flood control strategies (both adaptive and nonadaptive ones), the challenge of rising land-sea level differences, and various high tide level scenarios generated from modifying the statistical variances and averages. Our results show that adaptive forms of flood control strategies tend to outperform nonadaptive ones for maintaining the model community's flood protection system. Adaptive strategies that dynamically adjust target flood protection levels through close monitoring of flood damages and social memories of flood risk can help the model community deal with various disturbances.

The Contribution of Reservoirs to Global Land Surface Water Storage Variations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, Tian; Nijssen, Bart; Gao, Huilin

Man-made reservoirs play a key role in the terrestrial water system. They alter water fluxes at the land surface and impact surface water storage through water management regulations for diverse purposes such as irrigation, municipal water supply, hydropower generation, and flood control. Although most developed countries have established sophisticated observing systems for many variables in the land surface water cycle, long-term and consistent records of reservoir storage are much more limited and not always shared. Furthermore, most land surface hydrological models do not represent the effects of water management activities. Here, the contribution of reservoirs to seasonal water storage variationsmore » is investigated using a large-scale water management model to simulate the effects of reservoir management at basin and continental scales. The model was run from 1948 to 2010 at a spatial resolution of 0.258 latitude–longitude. A total of 166 of the largest reservoirs in the world with a total capacity of about 3900 km3 (nearly 60%of the globally integrated reservoir capacity) were simulated. The global reservoir storage time series reflects the massive expansion of global reservoir capacity; over 30 000 reservoirs have been constructed during the past half century, with a mean absolute interannual storage variation of 89 km3. The results indicate that the average reservoir-induced seasonal storage variation is nearly 700 km3 or about 10%of the global reservoir storage. For some river basins, such as the Yellow River, seasonal reservoir storage variations can be as large as 72%of combined snow water equivalent and soil moisture storage.« less

Sacramento Metropolitan Area, California

DTIC Science & Technology

1992-02-01

restriction would apply to virtually all of West Sacramento. Future conditions in the bypass areas are expected to remain essentially the same. During...frequency, the stage-frequency curve in the study area essentially becomes flat because of the large storage volume behind upstream levee breaches. This curve...and 400-year flood plains are also essentially the same (15 to 16 feet) because of the following: 1) the flood volume for each event is sufficient to

The role of carbohydrates in seed germination and seedling establishment of Himatanthus sucuuba, an Amazonian tree with populations adapted to flooded and non-flooded conditions

PubMed Central

da Silva Ferreira, Cristiane; Piedade, Maria Teresa Fernandez; Tiné, Marco Aurélio Silva; Rossatto, Davi Rodrigo; Parolin, Pia; Buckeridge, Marcos Silveira

2009-01-01

Background and Aims In the Amazonian floodplains plants withstand annual periods of flooding which can last 7 months. Under these conditions seedlings remain submerged in the dark for long periods since light penetration in the water is limited. Himatanthus sucuuba is a tree species found in the ‘várzea’ (VZ) floodplains and adjacent non-flooded ‘terra-firme’ (TF) forests. Biochemical traits which enhance flood tolerance and colonization success of H. sucuuba in periodically flooded environments were investigated. Methods Storage carbohydrates of seeds of VZ and TF populations were extracted and analysed by HPAEC/PAD. Starch was analysed by enzyme (glucoamylase) degradation followed by quantification of glucose oxidase. Carbohydrate composition of roots of VZ and TF seedlings was studied after experimental exposure to a 15-d period of submersion in light versus darkness. Key Results The endosperm contains a large proportion of the seed reserves, raffinose being the main non-structural carbohydrate. Around 93 % of the cell wall storage polysaccharides (percentage dry weight basis) in the endosperm of VZ seeds was composed of mannose, while soluble sugars accounted for 2·5%. In contrast, 74 % of the endosperm in TF seeds was composed of galactomannans, while 22 % of the endosperm was soluble sugars. This suggested a larger carbohydrate allocation to germination in TF populations whereas VZ populations allocate comparatively more to carbohydrates mobilized during seedling development. The concentration of root non-structural carbohydrates in non-flooded seedlings strongly decreased after a 15-d period of darkness, whereas flooded seedlings were less affected. These effects were more pronounced in TF seedlings, which showed significantly lower root non-structural carbohydrate concentrations. Conclusions There seem to be metabolic adjustments in VZ but not TF seedlings that lead to adaptation to the combined stresses of darkness and flooding. This seems to be important for the survival of the species in these contrasting environments, leading these populations to different directions during evolution. PMID:19770164

Bathymetry and capacity of Shawnee Reservoir, Oklahoma, 2016

USGS Publications Warehouse

Ashworth, Chad E.; Smith, S. Jerrod; Smith, Kevin A.

2017-02-13

Shawnee Reservoir (locally known as Shawnee Twin Lakes) is a man-made reservoir on South Deer Creek with a drainage area of 32.7 square miles in Pottawatomie County, Oklahoma. The reservoir consists of two lakes connected by an equilibrium channel. The southern lake (Shawnee City Lake Number 1) was impounded in 1935, and the northern lake (Shawnee City Lake Number 2) was impounded in 1960. Shawnee Reservoir serves as a municipal water supply, and water is transferred about 9 miles by gravity to a water treatment plant in Shawnee, Oklahoma. Secondary uses of the reservoir are for recreation, fish and wildlife habitat, and flood control. Shawnee Reservoir has a normal-pool elevation of 1,069.0 feet (ft) above North American Vertical Datum of 1988 (NAVD 88). The auxiliary spillway, which defines the flood-pool elevation, is at an elevation of 1,075.0 ft.The U.S. Geological Survey (USGS), in cooperation with the City of Shawnee, has operated a real-time stage (water-surface elevation) gage (USGS station 07241600) at Shawnee Reservoir since 2006. For the period of record ending in 2016, this gage recorded a maximum stage of 1,078.1 ft on May 24, 2015, and a minimum stage of 1,059.1 ft on April 10–11, 2007. This gage did not report reservoir storage prior to this report (2016) because a sufficiently detailed and thoroughly documented bathymetric (reservoir-bottom elevation) survey and corresponding stage-storage relation had not been published. A 2011 bathymetric survey with contours delineated at 5-foot intervals was published in Oklahoma Water Resources Board (2016), but that publication did not include a stage-storage relation table. The USGS, in cooperation with the City of Shawnee, performed a bathymetric survey of Shawnee Reservoir in 2016 and released the bathymetric-survey data in 2017. The purposes of the bathymetric survey were to (1) develop a detailed bathymetric map of the reservoir and (2) determine the relations between stage and reservoir storage capacity and between stage and reservoir surface area. The bathymetric map may serve as a baseline to which temporal changes in storage capacity, due to sedimentation and other factors, can be compared. The stage-storage relation may be used in the reporting of real-time Shawnee Reservoir storage capacity at USGS station 07241600 to support water-resource management decisions by the City of Shawnee.

Process-orientated simulation of tillage practices and land use change to optimize distributed flood control measures

NASA Astrophysics Data System (ADS)

Disse, M.; Rieger, W.

2009-04-01

Not only climate change affects hydrological systems but also land use change and agricultural tillage practises have an important impact on infiltration and runoff generation. In the last five to six decades monocropping, drainage and rectification of small rivers were carried out to optimize crop yields and economic benefits. However, in recent years more holistic and sustainable management concepts are required. The advantages of ecological management of land, soil and water resources are manifold: the biodiversity is higher, the buffer function of soils will be conserved and both low water and floods are positive affected. The target of the presented research project which is financed by the Bavarian environment agency, is to establish an optimal flood retention concept in a mesoscale catchment of 150 km² which emphasizes ecological flood measures like best tillage practices, small retention basins and renaturation of small rivers. To quantify the effects of these measures the water balance model WaSiM-ETH was used. The grid-based water flow and balance simulation model WaSiM-ETH is a well-established tool for investigating the spatial and temporal variability of hydrological processes in complex river basins. The model can be seen as a reasonable compromise between detailed physical basis and minimum data requirements (http://www.wasim.ch/en/index.html). WaSiM was coupled with a 2d-ground water model and an additional drainage tool. Different vegetation was parameterized with high spatial and temporal resolution. Additionally, future climate scenarios like the extension of vegetation periods were considered. The effectiveness of decentralized retention basins could be simulated by a new implemented see storage tool. The presentation will give quantitative results for different flood control measures. The pros and cons of physically based approaches in hydrological modelling will be discussed.

Floodplain-mapping With Modern It-instruments

NASA Astrophysics Data System (ADS)

Bley, D.; Pasche, E.

of all natural hazards, floods occur globally most frequently, claim most casualities and cause the biggest economic losses. Reasons are anthropogenic changes (river cor- rection, land surface sealing, waldsterben, climatic changes) combined with a high population density. Counteractions must be the resettlement of human beings away from flood-prone areas, flood controls and environmental monitoring, as well as renat- uralization and provision of retention basins and areas. The consequence, especially if we think of the recent flood-events on the rivers Rhine, Odra and Danube must be a preventive and sustainable flood control. As a consequence the legislator de- manded in the Water Management Act nation-wide floodplain-mapping, to preserve the necessary retention-areas for high water flows and prevent misuses. In this context, water level calculations based on a one-dimensional steady-flow computer model are among the major tasks in hydraulic engineering practice. Bjoernsen Consulting En- gineers developed in cooperation with the Technical University of Hamburg-Harburg the integrated software system WSPWIN. It is based upon state of the art informa- tion technology and latest developments in hydraulic research. WSPWIN consists of a pre-processing module, a calculation core, and GIS-based post-processing elements. As water level calculations require the recording and storage of large amounts of to- pographic and hydraulic data it is helpful that WSPWIN consists of an interactive graphical profile-editor, which allows visual data checking and editing. The calcu- lation program comprises water level calculations under steady uniform and steady non-uniform flow conditions using the formulas of Darcy-Weisbach and Gauckler- Manning-Strickler. Bridges, weirs, pipes as well as the effects of submerged vege- tation are taken into account. Post-processing includes plotting facilities for cross- sectional and longitudinal profiles as well as map-oriented GIS-based data editing and result presentation. Import of digital elevation models and generation of profiles are possible. Furthermore, the intersection of the DEM with the calculated water level en- ables the creation of floodplain maps. WSPWIN is the official standard software for one-dimensional hydraulic modeling in six German Federal States, where it is used by all water-management agencies. Moreover, many private companies, universities and water-associations employ WSPWIN as well. The program is presented showing the procedure and difficulties of floodplain-mapping and flood control on a Bavarian river.

Flooding of the root system in soybean: biochemical and molecular aspects of N metabolism in the nodule during stress and recovery.

PubMed

Souza, Sarah C R; Mazzafera, Paulo; Sodek, Ladaslav

2016-05-01

Nitrogen fixation of the nodule of soybean is highly sensitive to oxygen deficiency such as provoked by waterlogging of the root system. This study aimed to evaluate the effects of flooding on N metabolism in nodules of soybean. Flooding resulted in a marked decrease of asparagine (the most abundant amino acid) and a concomitant accumulation of γ-aminobutyric acid (GABA). Flooding also resulted in a strong reduction of the incorporation of (15)N2 in amino acids. Nodule amino acids labelled before flooding rapidly lost (15)N during flooding, except for GABA, which initially increased and declined slowly thereafter. Both nitrogenase activity and the expression of nifH and nifD genes were strongly decreased on flooding. Expression of the asparagine synthetase genes SAS1 and SAS2 was reduced, especially the former. Expression of genes encoding the enzyme glutamic acid decarboxylase (GAD1, GAD4, GAD5) was also strongly suppressed except for GAD2 which increased. Almost all changes observed during flooding were reversible after draining. Possible changes in asparagine and GABA metabolism that may explain the marked fluctuations of these amino acids during flooding are discussed. It is suggested that the accumulation of GABA has a storage role during flooding stress.

Real-time Ensemble Flow Forecasts for a 2017 Mock Operation Test Trial of Forecast Informed Reservoir Operations for Lake Mendocino in Mendocino County, California

NASA Astrophysics Data System (ADS)

Delaney, C.; Mendoza, J.; Jasperse, J.; Hartman, R. K.; Whitin, B.; Kalansky, J.

2017-12-01

Forecast informed reservoir operations (FIRO) is a methodology that incorporates short to mid-range precipitation and flow forecasts to inform the flood operations of reservoirs. The Ensemble Forecast Operations (EFO) alternative is a probabilistic approach of FIRO that incorporates 15-day ensemble streamflow predictions (ESPs) made by NOAA's California-Nevada River Forecast Center (CNRFC). With the EFO approach, release decisions are made to manage forecasted risk of reaching critical operational thresholds. A water management model was developed for Lake Mendocino, a 111,000 acre-foot reservoir located near Ukiah, California, to conduct a mock operation test trial of the EFO alternative for 2017. Lake Mendocino is a dual use reservoir, which is owned and operated for flood control by the United States Army Corps of Engineers and is operated for water supply by the Sonoma County Water Agency. Due to recent changes in the operations of an upstream hydroelectric facility, this reservoir has suffered from water supply reliability issues since 2007. The operational trial utilized real-time ESPs prepared by the CNRFC and observed flow information to simulate hydrologic conditions in Lake Mendocino and a 50-mile downstream reach of the Russian River to the City of Healdsburg. Results of the EFO trial demonstrate a 6% increase in reservoir storage at the end of trial period (May 10) relative to observed conditions. Additionally, model results show no increase in flows above flood stage for points downstream of Lake Mendocino. Results of this investigation and other studies demonstrate that the EFO alternative may be a viable flood control operations approach for Lake Mendocino and warrants further investigation through additional modeling and analysis.

Flood inundation extent mapping based on block compressed tracing

NASA Astrophysics Data System (ADS)

Shen, Dingtao; Rui, Yikang; Wang, Jiechen; Zhang, Yu; Cheng, Liang

2015-07-01

Flood inundation extent, depth, and duration are important factors affecting flood hazard evaluation. At present, flood inundation analysis is based mainly on a seeded region-growing algorithm, which is an inefficient process because it requires excessive recursive computations and it is incapable of processing massive datasets. To address this problem, we propose a block compressed tracing algorithm for mapping the flood inundation extent, which reads the DEM data in blocks before transferring them to raster compression storage. This allows a smaller computer memory to process a larger amount of data, which solves the problem of the regular seeded region-growing algorithm. In addition, the use of a raster boundary tracing technique allows the algorithm to avoid the time-consuming computations required by the seeded region-growing. Finally, we conduct a comparative evaluation in the Chin-sha River basin, results show that the proposed method solves the problem of flood inundation extent mapping based on massive DEM datasets with higher computational efficiency than the original method, which makes it suitable for practical applications.

Anthropogenic Water Uses and River Flow Regime Alterations by Dams

NASA Astrophysics Data System (ADS)

Ferrazzi, M.; Botter, G.

2017-12-01

Dams and impoundments have been designed to reconcile the systematic conflict between patterns of anthropogenic water uses and the temporal variability of river flows. Over the past seven decades, population growth and economic development led to a marked increase in the number of these water infrastructures, so that unregulated free-flowing rivers are now rare in developed countries and alterations of the hydrologic cycle at global scale have to be properly considered and characterized. Therefore, improving our understanding of the influence of dams and reservoirs on hydrologic regimes is going to play a key role in water planning and management. In this study, a physically based analytic approach is combined to extensive hydrologic data to investigate natural flow regime alterations downstream of dams in the Central-Eastern United States. These representative case studies span a wide range of different uses, including flood control, water supply and hydropower production. Our analysis reveals that the most evident effects of flood control through dams is a decrease in the intra-seasonal variability of flows, whose extent is controlled by the ratio between the storage capacity for flood control and the average incoming streamflow. Conversely, reservoirs used for water supply lead to an increase of daily streamflow variability and an enhanced inter-catchment heterogeneity. Over the last decades, the supply of fresh water required to sustain human populations has become a major concern at global scale. Accordingly, the number of reservoirs devoted to water supply increased by 50% in the US. This pattern foreshadows a possible shift in the cumulative effect of dams on river flow regimes in terms of inter-catchment homogenization and intra-annual flow variability.

Hydro-meteorological risk reduction and climate change adaptation in the Sava River Basin

NASA Astrophysics Data System (ADS)

Brilly, Mitja; Šraj, Mojca; Kryžanowski, Andrej

2017-04-01

The Sava River Basin covered the teritory of several countries. There were, in past thirty years, several flood hazard events with almost hundred years return period. Parts of the basin suffer by severe droughts also. In the presentation we covered questions of: • Flood hazard in complex hydrology structure • Landslide and flush flood in mountainous regions • Floods on karst polje • Flood risk management in the complex international and hydrological condition. • Impact of man made structures: hydropower storages, inundation ponds, river regulation, alternate streams, levees system, pumping stations, Natura 2000 areas etc. • How to manage droughts in the international river basin The basin is well covered by information and managed by international the SRB Commission (http://savacommission.org/) that could help. We develop study for climate change impact on floods on entire river basin financing by UNECE. There is also study provide climate change impact on the water management provide by World Bank and on which we take part. Recently is out call by world bank for study »Flood risk management plan for the SRB«.

Strategy of Water Pollution Control Base On Social Economic Activitiy, in Karang Mumus River, Samarinda East Kalimantan, Indonesia

NASA Astrophysics Data System (ADS)

Pramaningsih, Vita; Suprayogi, Slamet; Purnama, Setyawan

2018-02-01

Water Pollution in Karang Mumus River caused society behavior along the river. Daily activity such as bath, washing and defecate at the river. Garbage, sediment, domestic waste and flood are river problems should be solved. Purpose this research is make strategy of water pollution control in the Karang Mumus River. Method used observation in the field, interview to the society, industry, public activity along the river and government of environment department. Further create data using tool of Analysis Hierarchy Process (AHP) to get the strategy to control water pollution in the river. Actors have contribute pollution control are government, industry and society. Criteria to pollution control are society participation, low, human resources and sustainable. Alternative of pollution control are unit garbage storage; license loyalty for industry and waste; communal waste water installation; monitoring of water quality. Result for actor priority are government (0.4); Industry (0.4); Society (0.2). Result for priority criteria are society participation (0.338), low (0.288), human resources (0.205) and sustainable (0.169). Result for priority alternative are unit garbage storage (0.433); license loyalty for industry and waste (0.238); communal waste water installation (0.169); monitoring of water quality (0.161).

Mechanisms involved in the regulation of photosynthetic efficiency and carbohydrate partitioning in response to low- and high-temperature flooding triggered in winter rye (Secale cereale) lines with distinct pink snow mold resistances.

PubMed

Pociecha, E; Rapacz, M; Dziurka, M; Kolasińska, I

2016-07-01

In terms of climate changes and global warming, winter hardiness could be determined by unfavorable environmental conditions other than frost. These could include flooding from melting snow and/or rain, coincident with fungal diseases. Therefore, we designed an experiment to identify potential common mechanisms of flooding tolerance and snow mold resistance, involving the regulation of photosynthetic efficiency and carbohydrate metabolism at low temperatures. Snow mold-resistant and susceptible winter rye (Secale cereale) plants were characterized by considerably different patterns of response to flooding. These differences were clearer at low temperature, thus confirming a possible role of the observed changes in snow mold tolerance. The resistant plants were characterized by lower PSII quantum yields at low temperature, combined with much higher energy flux for energy dissipation from the PSII reaction center. During flooding, the level of soluble carbohydrates increased in the resistant plants and decreased in the susceptible ones. Thus increase in resistant line was connected with a decrease in the energy dissipation rate in PSII/increased photosynthetic activity (energy flux for electron transport), a lower rate of starch degradation and higher rates of sucrose metabolism in leaves. The resistant lines accumulated larger amounts of total soluble carbohydrates in the crowns than in the leaves. Irrespective of flooding treatment, the resistant lines allocated more sugars for cell wall composition, both in the leaves and crowns. Our results clearly indicated that studies on carbohydrate changes at low temperatures or during anoxia should investigate not only the alterations in water-soluble and storage carbohydrates, but also cell wall carbohydrates. The patterns of changes observed after low and high-temperature flooding were different, indicating separate control mechanisms of these responses. These included changes in the photosynthetic apparatus, starch accumulation and cell wall carbohydrate accumulation. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Deglacial climate modulated by the storage and release of Arctic sea ice

NASA Astrophysics Data System (ADS)

Condron, A.; Coletti, A. J.; Bradley, R. S.

2017-12-01

Periods of abrupt climate cooling during the last deglaciation (20 - 8 kyr ago) are often attributed to glacial outburst floods slowing the Atlantic meridional overturning circulation (AMOC). Here, we present results from a series of climate model simulations showing that the episodic break-up and mobilization of thick, perennial, Arctic sea ice during this time would have released considerable volumes of freshwater directly to the Nordic Seas, where processes regulating large-scale climate occur. Massive sea ice export events to the North Atlantic are generated whenever the transport of sea ice is enhanced, either by changes in atmospheric circulation, rising sea level submerging the Bering land bridge, or glacial outburst floods draining into the Arctic Ocean from the Mackenzie River. We find that the volumes of freshwater released to the Nordic Seas are similar to, or larger than, those estimated to have come from terrestrial outburst floods, including the discharge at the onset of the Younger Dryas. Our results provide the first evidence that the storage and release of Arctic sea ice helped drive deglacial climate change by modulating the strength of the AMOC.

Pleistocene lake outburst floods and fan formation along the eastern Sierra Nevada, California: implications for the interpretation of intermontane lacustrine records

NASA Astrophysics Data System (ADS)

Benn, Douglas I.; Owen, Lewis A.; Finkel, Robert C.; Clemmens, Samuel

2006-11-01

Variations in the rock flour fraction in intermontane lacustrine sediments have the potential to provide more complete records of glacier fluctuations than moraine sequences, which are subject to erosional censoring. Construction of glacial chronologies from such records relies on the assumption that rock flour concentration is a simple function of glacier extent. However, other factors may influence the delivery of glacigenic sediments to intermontane lakes, including paraglacial adjustment of slope and fluvial systems to deglaciation, variations in precipitation and snowmelt, and lake outburst floods. We have investigated the processes and chronology of sediment transport on the Tuttle and Lone Pine alluvial fans in the eastern Sierra Nevada, California, USA, to elucidate the links between former glacier systems located upstream and the long sedimentary record from Owens Lake located downstream. Aggradation of both fans reflects sedimentation by three contrasting process regimes: (1) high magnitude, catastrophic floods, (2) fluvial or glacifluvial river systems, and (3) debris flows and other slope processes. Flood deposits are represented by multiple boulder beds exposed in section, and extensive networks of large palaeochannels and boulder deposits on both fan surfaces. Palaeohydrological analysis implies peak discharges in the order of 10 3-10 4 m 3 s -1, most probably as the result of catastrophic drainage of ice-, moraine-, and landslide-dammed lakes. Cosmogenic radionuclide surface exposure dating shows that at least three flood events are represented on each fan, at 9-13, 16-18 and 32-44 ka (Tuttle Fan); and at ˜23-32, ˜80-86 ka, and a poorly constrained older event (Lone Pine Fan). Gravels and sands exposed in both fans represent fluvial and/or glacifluvial sediment transport from the Sierra Nevada into Owens Valley, and show that river systems incised and reworked older sediment stored in the fans. We argue that millennial-scale peaks in rock flour abundance in the Owens Lake core reflect (1) fluctuations in primary subglacial erosion in the catchments in response to glacier advance-retreat cycles; (2) short-lived pulses of sediment delivered directly by catastrophic flood events; and (3) sediment released from storage in alluvial fans by fluvial and glacifluvial incision and reworking. As a result of this complexity the coarse sediment peaks in lake deposits may not simply reflect periods of increased glaciation, but likely also reflect changes in sediment storage and flux controlled by paraglacial processes. Current dating evidence is inadequate to allow precise correlation of individual flood or incision events with the Owens Lake rock flour record, although given the widespread occurrence of flood deposits in fans along the eastern margins of the Sierra Nevada, it is clear that fan deposition and incision played a very important role in modulating the delivery of glacigenic sediment to Owens Lake.

A hybrid deep neural network and physically based distributed model for river stage prediction

NASA Astrophysics Data System (ADS)

hitokoto, Masayuki; sakuraba, Masaaki

2016-04-01

We developed the real-time river stage prediction model, using the hybrid deep neural network and physically based distributed model. As the basic model, 4 layer feed-forward artificial neural network (ANN) was used. As a network training method, the deep learning technique was applied. To optimize the network weight, the stochastic gradient descent method based on the back propagation method was used. As a pre-training method, the denoising autoencoder was used. Input of the ANN model is hourly change of water level and hourly rainfall, output data is water level of downstream station. In general, the desirable input of the ANN has strong correlation with the output. In conceptual hydrological model such as tank model and storage-function model, river discharge is governed by the catchment storage. Therefore, the change of the catchment storage, downstream discharge subtracted from rainfall, can be the potent input candidate of the ANN model instead of rainfall. From this point of view, the hybrid deep neural network and physically based distributed model was developed. The prediction procedure of the hybrid model is as follows; first, downstream discharge was calculated by the distributed model, and then estimates the hourly change of catchment storage form rainfall and calculated discharge as the input of the ANN model, and finally the ANN model was calculated. In the training phase, hourly change of catchment storage can be calculated by the observed rainfall and discharge data. The developed model was applied to the one catchment of the OOYODO River, one of the first-grade river in Japan. The modeled catchment is 695 square km. For the training data, 5 water level gauging station and 14 rain-gauge station in the catchment was used. The training floods, superior 24 events, were selected during the period of 2005-2014. Prediction was made up to 6 hours, and 6 models were developed for each prediction time. To set the proper learning parameters and network architecture of the ANN model, sensitivity analysis was done by the case study approach. The prediction result was evaluated by the superior 4 flood events by the leave-one-out cross validation. The prediction result of the basic 4 layer ANN was better than the conventional 3 layer ANN model. However, the result did not reproduce well the biggest flood event, supposedly because the lack of the sufficient high-water level flood event in the training data. The result of the hybrid model outperforms the basic ANN model and distributed model, especially improved the performance of the basic ANN model in the biggest flood event.

Cascade reservoir flood control operation based on risk grading and warning in the Upper Yellow River

NASA Astrophysics Data System (ADS)

Xuejiao, M.; Chang, J.; Wang, Y.

2017-12-01

Flood risk reduction with non-engineering measures has become the main idea for flood management. It is more effective for flood risk management to take various non-engineering measures. In this paper, a flood control operation model for cascade reservoirs in the Upper Yellow River was proposed to lower the flood risk of the water system with multi-reservoir by combining the reservoir flood control operation (RFCO) and flood early warning together. Specifically, a discharge control chart was employed to build the joint RFCO simulation model for cascade reservoirs in the Upper Yellow River. And entropy-weighted fuzzy comprehensive evaluation method was adopted to establish a multi-factorial risk assessment model for flood warning grade. Furthermore, after determining the implementing mode of countermeasures with future inflow, an intelligent optimization algorithm was used to solve the optimization model for applicable water release scheme. In addition, another model without any countermeasure was set to be a comparative experiment. The results show that the model developed in this paper can further decrease the flood risk of water system with cascade reservoirs. It provides a new approach to flood risk management by coupling flood control operation and flood early warning of cascade reservoirs.

National Program for Inspection of Non-Federal Dams. Old Quincy Reservoir Dam (MA 00827), Massachusetts-Rhode Island Coastal Basin, Braintree, Massachusetts. Phase I Inspection Report.

DTIC Science & Technology

1979-11-01

flood protection to the urban - ized area located downstream along Town Brook. The pond has a water surface area of approximately 36 acres and a storage...in a 1970 paper entitled "Effect of Urban Expansion on Hydrologic Investigations". A peak inflow rate of 1760 csm was adopted for the 1.44 sq. mi...etc. C. None. 2. Weir 2. a. Flashboards a. None. b. Weir Elev. Control (Gate) b. None. c. Vegetation c. Light brush and weeds - two trees d. Seepage or

Land use change in the last century in the Veneto floodplain: effects on network drainage density, water storage, and related consequences on flood risk

NASA Astrophysics Data System (ADS)

Prosdocimi, Massimo; Sofia, Giulia; Dalla Fontana, Giancarlo; Tarolli, Paolo

2013-04-01

In a high-density populated country such as Italy, the anthropic pressure plays a fundamental role in the alteration and the modification of the landscape. Among the most evident anthropic alterations, the most important are the urbanization processes that have been occurring since the end of the second world war. Agricultural activities, housing and other land uses have shifted due to the progressive spreading of urban areas. These modifications affect the hydrologic regimes, but municipalities often are not aware of the real impact of land cover changes on such processes and, consequently, an increase of the elements at risk of flooding is generally registered. The main objective of this work is to evaluate the impact of land cover changes in the Veneto region (north-east Italy), from 1954 to 2006, on the minor drainage network system and on its capacity to attenuate the direct runoff. The major flood event occurred between October and November 2010. The study is a typical agrarian landscape and it has been chosen considering its involvement inthe major flood of 2010 and considering also the availability of high-resolution topographic data (LiDAR-derived DTMs) and historical aerial photographs. Aerial photographs dated back to 1954 and 1981, in particular, have been used either to classify the land cover in five categories according to the first level of the CORINE land cover classification and to identify the minor drainage network. A semi-automatic approach based on the high-resolution DTM (Cazorzi et al., 2012), was also considered to identify the minor drainage network and estimate its water storage capacity. The results underline how land cover variation over the last 50 years has strongly increased the propension of the soil to produce direct runoff (increase of the Curve Number value) and it has also reduced the extent of the minor network system. As a consequence, the capacity of the agrarian minor network to attenuate and laminate a flood event is decreased as well. These analysis can be considered useful tools for a suitable land use planning in flood prone areas. References Cazorzi, F., Dalla Fontana, G., De Luca, A., Sofia, G., Tarolli, P. (2012). Drainage network detection and assessment of network storage capacity in agrarian landscape, Hydrological Processes, ISSN: 0885-6087, doi:10.1002/hyp.9224

Injection and Monitoring at the Wallula Basalt Pilot Project

DOE PAGES

McGrail, B. Peter; Spane, Frank A.; Amonette, James E.; ...

2014-01-01

Continental flood basalts represent one of the largest geologic structures on earth but have received comparatively little attention for geologic storage of CO2. Flood basalt lava flows have flow tops that are porous, permeable, and have large potential capacity for storage of CO2. In appropriate geologic settings, interbedded sediment layers and dense low-permeability basalt rock flow interior sections may act as effective seals allowing time for mineralization reactions to occur. Previous laboratory experiments showed the relatively rapid chemical reaction of CO2-saturated pore water with basalts to form stable carbonate minerals. However, recent laboratory tests with water-saturated supercritical CO2 show thatmore » mineralization reactions occur in this phase as well, providing a second and potentially more important mineralization pathway than was previously understood. Field testing of these concepts is proceeding with drilling of the world’s first supercritical CO2 injection well in flood basalt being completed in May 2009 near the township of Wallula in Washington State and corresponding CO2 injection permit granted by the State of Washington in March 2011. Injection of a nominal 1000 MT of CO2 was completed in August 2013 and site monitoring is in progress. Well logging conducted immediately after injection termination confirmed the presence of CO2 predominantly within the upper flow top region, and showed no evidence of vertical CO2 migration outside the well casing. Shallow soil gas samples collected around the injection well show no evidence of leakage and fluid and gas samples collected from the injection zone show strongly elevated concentrations of Ca, Mg, Mn, and Fe and 13C/18O isotopic shifts that are consistent with basalt-water chemical reactions. If proven viable by this field test and others that are in progress or being planned, major flood basalts in the U.S., India, and perhaps Australia would provide significant additional CO2 storage capacity and additional geologic sequestration options in regions of these countries where conventional storage options are limited.« less

Physical parameters of Fluvisols on flooded and non-flooded terraces

NASA Astrophysics Data System (ADS)

Kercheva, Milena; Sokołowska, Zofia; Hajnos, Mieczysław; Skic, Kamil; Shishkov, Toma

2017-01-01

The heterogeneity of soil physical properties of Fluvisols, lack of large pristine areas, and different moisture regimes on non-flooded and flooded terraces impede the possibility to find a soil profile which can serve as a baseline for estimating the impact of natural or anthropogenic factors on soil evolution. The aim of this study is to compare the pore size distribution of pristine Fluvisols on flooded and non-flooded terraces using the method of the soil water retention curve, mercury intrusion porosimetry, nitrogen adsorption isotherms, and water vapour sorption. The pore size distribution of humic horizons of pristine Fluvisols on the non-flooded terrace differs from pore size distribution of Fluvisols on the flooded terrace. The peaks of textural and structural pores are higher in the humic horizons under more humid conditions. The structural characteristics of subsoil horizons depend on soil texture and evolution stage. The peaks of textural pores at about 1 mm diminish with lowering of the soil organic content. Structureless horizons are characterized by uni-modal pore size distribution. Although the content of structural pores of the subsoil horizons of Fluvisols on the non-flooded terrace is low, these pores are represented by biopores, as the coefficient of filtration is moderately high. The difference between non-flooded and flooded profiles is well expressed by the available water storage, volume and mean radius of pores, obtained by mercury intrusion porosimetry and water desorption, which are higher in the surface horizons of frequently flooded Fluvisols.

Priority and construction sites of water storage in a watershed in response to climate change

NASA Astrophysics Data System (ADS)

Lin, Cheng-Yu; Zhang, Wen-Yan; Lin, Chao-Yuan

2014-05-01

Taiwan is located at the Eastern Asia Monsoon climate zone. Typhoons and/or convectional rains occur frequently and result in high intensity storms in the summer season. Once the detention facilities are shortage or soil infiltration rate become worse in a watershed due to land use, surface runoff is easily to concentrate and threaten the protected areas. Therefore, it is very important to examine the functionality of water storage for a watershed. The purpose of this study is to solve the issue of flooding in the Puzi Creek. A case study of Yizen Bridge Watershed, in which the SCS curve number was used as an index to extract the spatial distribution of the strength of water storage, and the value of watershed mean CN along the main channel was calculated using area-weighting method. Therefore, the hotspot management sites were then derived and the priority method was applied to screen the depression sites for the reference of management authorities in detention ponds placement. The results show that the areas of subzone A with the characteristics of bad condition in topography and soil, which results in poor infiltration. However, the areas are mostly covered with forest and are difficult to create the artificial water storage facilities. Detention dams are strongly recommended at the site of depression in the river channel to decrease discharge velocity and reduce impact from flood disaster. The areas of subzone B are mainly located at the agriculture slope land. The topographic depressions in the farmland are the suitable places to construct the farm ponds for the use of flood detention and sediment deposition in the rainy seasons and irrigation in the dry seasons. Areas of subzone C are mainly occupied the gentle slope land with a better ability in water storage due to low CN value. Farm ponds constructed in the riparian to bypass the nearby river channel can create multifunctional wetland to effectively decrease the peak discharge in the downstream during storm events. Depression storages are based on additional runoff obtained from CN calculation. Strategies mentioned in this study can be provided as references of climate change adaptions for related authorities.

Spatial and Temporal Influences on Carbon Storage in Hydric Soils of the Conterminous United States

NASA Astrophysics Data System (ADS)

Sundquist, E. T.; Ackerman, K.; Bliss, N.; Griffin, R.; Waltman, S.; Windham-Myers, L.

2016-12-01

Defined features of hydric soils persist over extensive areas of the conterminous United States (CUS) long after their hydric formation conditions have been altered by historical changes in land and water management. These legacy hydric features may represent previous wetland environments in which soil carbon storage was significantly higher before the influence of human activities. We hypothesize that historical alterations of hydric soil carbon storage can be approximated using carefully selected estimates of carbon storage in currently identified hydric soils. Using the Soil Survey Geographic (SSURGO) database, we evaluate carbon storage in identified hydric soil components that are subject to discrete ranges of current or recent conditions of flooding, ponding, and other indicators of hydric and non-hydric soil associations. We check our evaluations and, where necessary, adjust them using independently published soil data. We compare estimates of soil carbon storage under various hydric and non-hydric conditions within proximal landscapes and similar biophysical settings and ecosystems. By combining these setting- and ecosystem-constrained comparisons with the spatial distribution and attributes of wetlands in the National Wetlands Inventory, we impute carbon storage estimates for soils that occur in current wetlands and for hydric soils that are not associated with current wetlands. Using historical data on land use and water control structures, we map the spatial and temporal distribution of past changes in land and water management that have affected hydric soils. We combine these maps with our imputed carbon storage estimates to calculate ranges of values for historical and present-day carbon storage in hydric soils throughout the CUS. These estimates may provide useful constraints for projections of potential carbon storage in hydric soils under future conditions.

Flood information for flood-plain planning

USGS Publications Warehouse

Bue, Conrad D.

1967-01-01

Floods are natural and normal phenomena. They are catastrophic simply because man occupies the flood plain, the highwater channel of a river. Man occupies flood plains because it is convenient and profitable to do so, but he must purchase his occupancy at a price-either sustain flood damage, or provide flood-control facilities. Although large sums of money have been, and are being, spent for flood control, flood damage continues to mount. However, neither complete flood control nor abandonment of the flood plain is practicable. Flood plains are a valuable resource and will continue to be occupied, but the nature and degree of occupancy should be compatible with the risk involved and with the degree of protection that is practicable to provide. It is primarily to meet the needs for defining the risk that the flood-inundation maps of the U.S. Geological Survey are prepared.

On identifying relationships between the flood scaling exponent and basin attributes.

PubMed

Medhi, Hemanta; Tripathi, Shivam

2015-07-01

Floods are known to exhibit self-similarity and follow scaling laws that form the basis of regional flood frequency analysis. However, the relationship between basin attributes and the scaling behavior of floods is still not fully understood. Identifying these relationships is essential for drawing connections between hydrological processes in a basin and the flood response of the basin. The existing studies mostly rely on simulation models to draw these connections. This paper proposes a new methodology that draws connections between basin attributes and the flood scaling exponents by using observed data. In the proposed methodology, region-of-influence approach is used to delineate homogeneous regions for each gaging station. Ordinary least squares regression is then applied to estimate flood scaling exponents for each homogeneous region, and finally stepwise regression is used to identify basin attributes that affect flood scaling exponents. The effectiveness of the proposed methodology is tested by applying it to data from river basins in the United States. The results suggest that flood scaling exponent is small for regions having (i) large abstractions from precipitation in the form of large soil moisture storages and high evapotranspiration losses, and (ii) large fractions of overland flow compared to base flow, i.e., regions having fast-responding basins. Analysis of simple scaling and multiscaling of floods showed evidence of simple scaling for regions in which the snowfall dominates the total precipitation.

Forecasting Total Water Storage Changes in the Amazon basin using Atlantic and Pacific Sea Surface Temperatures

NASA Astrophysics Data System (ADS)

De Linage, C.; Famiglietti, J. S.; Randerson, J. T.

2013-12-01

Floods and droughts frequently affect the Amazon River basin, impacting the transportation, river navigation, agriculture, economy and the carbon balance and biodiversity of several South American countries. The present study aims to find the main variables controlling the natural interannual variability of terrestrial water storage in the Amazon region and to propose a modeling framework for flood and drought forecasting. We propose three simple empirical models using a linear combination of lagged spatial averages of central Pacific (Niño 4 index) and tropical North Atlantic (TNAI index) sea surface temperatures (SST) to predict a decade-long record of 3°, monthly terrestrial water storage anomalies (TWSA) observed by the Gravity Recovery And Climate Experiment (GRACE) mission. In addition to a SST forcing term, the models included a relaxation term to simulate the memory of water storage anomalies in response to external variability in forcing. Model parameters were spatially-variable and individually optimized for each 3° grid cell. We also investigated the evolution of the predictive capability of our models with increasing minimum lead times for TWSA forecasts. TNAI was the primary external forcing for the central and western regions of the southern Amazon (35% of variance explained with a 3-month forecast), whereas Niño 4 was dominant in the northeastern part of the basin (61% of variance explained with a 3-month forecast). Forcing the model with a combination of the two indices improved the fit significantly (p<0.05) for at least 64% of the grid cells, compared to models forced solely with Niño 4 or TNAI. The combined model was able to explain 43% of the variance in the Amazon basin as a whole with a 3-month lead time. While 66% of the observed variance was explained in the northeastern Amazon, only 39% of the variance was captured by the combined model in the central and western regions, suggesting that other, more local, forcing sources were important in these regions. The predictive capability of the combined model was monotonically degraded with increasing lead times. Degradation was smaller in the northeastern Amazon (where 49% of the variance was explained using a 8-month lead time versus 69% for a 1 month lead time) compared to the western and central regions of southern Amazon (where 22% of the variance was explained at 8 months versus 43% at 1 month). Our model may provide early warning information about flooding in the northeastern region of the Amazon basin, where floodplain areas are extensive and the sensitivity of floods to external SST forcing was shown to be high. This work also strengthens our understanding of the mechanisms regulating interannual variability in Amazon fires, as TWSA deficits may subsequently lead to atmospheric water vapor deficits and reduced cloudiness via water-limited evapotranspiration. Finally, this work helps to bridge the gap between the current GRACE mission and the follow-on gravity mission.

Deciphering flood frequency curves from a coupled human-nature system perspective

NASA Astrophysics Data System (ADS)

Li, H. Y.; Abeshu, G. W.; Wang, W.; Ye, S.; Guo, J.; Bloeschl, G.; Leung, L. R.

2017-12-01

Most previous studies and applications in deriving or applying FFC are underpinned by the stationarity assumption. To examine the theoretical robustness of this basic assumption, we analyzed the observed FFCs at hundreds of catchments in the contiguous United States along the gradients of climate conditions and human influences. The shape of FFCs is described using three similarity indices: mean annual floods (MAF), coefficient of variance (CV), and a seasonality index defined using circular statistics. The characteristics of catchments are quantified with a small number of dimensionless indices, including particularly: 1) the climatic aridity index, AI, which is a measure of the competition between energy and water availability; 2) reservoir impact index, defined as the total upstream reservoir storage capacity normalized by the annual streamflow volume. The linkages between these two sets of indices are then explored based on a combination of mathematical derivations of the Budyko formula, simple but physically based reservoir operation models, and other auxiliary data. It is found that the shape of FFCs shifts from arid to humid climate, and from periods with weak human influences to periods with strong influences. The seasonality of floods is found to be largely controlled by the synchronization between the seasonal cycles of precipitation and solar radiation in pristine catchments, but also by the reservoir regulation capacity in managed catchments. Our findings may help improve flood-risk assessment and mitigation in both natural and regulated river systems across various climate gradients.

Flood risk analysis for flood control and sediment transportation in sandy regions: A case study in the Loess Plateau, China

NASA Astrophysics Data System (ADS)

Guo, Aijun; Chang, Jianxia; Wang, Yimin; Huang, Qiang; Zhou, Shuai

2018-05-01

Traditional flood risk analysis focuses on the probability of flood events exceeding the design flood of downstream hydraulic structures while neglecting the influence of sedimentation in river channels on regional flood control systems. This work advances traditional flood risk analysis by proposing a univariate and copula-based bivariate hydrological risk framework which incorporates both flood control and sediment transport. In developing the framework, the conditional probabilities of different flood events under various extreme precipitation scenarios are estimated by exploiting the copula-based model. Moreover, a Monte Carlo-based algorithm is designed to quantify the sampling uncertainty associated with univariate and bivariate hydrological risk analyses. Two catchments located on the Loess plateau are selected as study regions: the upper catchments of the Xianyang and Huaxian stations (denoted as UCX and UCH, respectively). The univariate and bivariate return periods, risk and reliability in the context of uncertainty for the purposes of flood control and sediment transport are assessed for the study regions. The results indicate that sedimentation triggers higher risks of damaging the safety of local flood control systems compared with the event that AMF exceeds the design flood of downstream hydraulic structures in the UCX and UCH. Moreover, there is considerable sampling uncertainty affecting the univariate and bivariate hydrologic risk evaluation, which greatly challenges measures of future flood mitigation. In addition, results also confirm that the developed framework can estimate conditional probabilities associated with different flood events under various extreme precipitation scenarios aiming for flood control and sediment transport. The proposed hydrological risk framework offers a promising technical reference for flood risk analysis in sandy regions worldwide.

Belford proactive flood solutions: scientific evidence to influence local and national policy by multi-purpose runoff management

NASA Astrophysics Data System (ADS)

Wilkinson, M.; Quinn, P. F.; Jonczyk, J.

2010-12-01

The increased risk from flooding continues to be of concern to governments all around the world and flood protection is becoming more of a challenge. In the UK, climate change projections indicate more extremes within the weather systems. In addition, there is an increased demand for using land in urban areas beside channels. These developments both put pressure on our flood defences and there is a need for new solutions to managing flood risk. There is currently support within the England and Wales Environment Agency for sustainable flood management solutions such as storage ponds, wetlands, beaver dams and willow riparian features (referred to here as Runoff Attenuation Features, or RAFs). However the effectiveness of RAFs are not known at the catchment scale since they have only really been trailed at the plot scale. These types of mitigation measure can offer benefits to water quality and create ecological habitats. The village of Belford, situated in the Belford Burn catchment (6km2), northern England, has suffered from numerous flood events. In addition, the catchment suffers from water quality issues within the channel and high sediment loads are having an impact on the ecology of the nearby estuary. There was a desire by the Local Environment Agency Flood Levy team to deliver an alternative catchment-based solution to the problem. With funding from the Northumbria Regional Flood Defence Committee, the Environment Agency North East Local Levy team and Newcastle University have created a partnership to address the flood problem trailing soft engineered RAF’s at the catchment scale. The partnership project, “Belford proactive flood solutions” is testing novel techniques in reducing flood risk in small sub-catchments for the Environment Agency. The project provides the information needed to understand whether the multi-functional mitigation measures are working at the sub-catchment scale. Data suggest that the mitigation measures present have delayed the overall travel time of the flood peak in the catchment by 33%. The current maximum flood storage capacity of all the features stands at around 15,000 m3. The evidence also suggests that a dam like in-stream mitigation measure can significantly reduce sediment load. Other benefits of some mitigation features include large increase in the population of water voles over the past two years. The scheme also acts as a demonstration site for interested stakeholders where they can learn about this approach to flood risk management and see the multipurpose benefits. As the project has progressed and lessons have been learnt, it has been possible to develop a runoff management toolkit for implementing these mitigation measures in other catchments of similar size. Already, the local Environment Agency has utilised the tools and recently applied similar mitigation measures to other catchments. On-going modelling exercises in the project are using the data to explore the up-scaling of the features to larger catchments.

Miniaturized Water Flow and Level Monitoring System for Flood Disaster Early Warning

NASA Astrophysics Data System (ADS)

Ifedapo Abdullahi, Salami; Hadi Habaebi, Mohamed; Surya Gunawan, Teddy; Rafiqul Islam, MD

2017-11-01

This study presents the performance of a prototype miniaturised water flow and water level monitoring sensor designed towards supporting flood disaster early warning systems. The design involved selection of sensors, coding to control the system mechanism, and automatic data logging and storage. During the design phase, the apparatus was constructed where all the components were assembled using locally sourced items. Subsequently, under controlled laboratory environment, the system was tested by running water through the inlet during which the flow rate and rising water levels are automatically recorded and stored in a database via Microsoft Excel using Coolterm software. The system is simulated such that the water level readings measured in centimeters is output in meters using a multiplicative of 10. A total number of 80 readings were analyzed to evaluate the performance of the system. The result shows that the system is sensitive to water level rise and yielded accurate measurement of water level. But, the flow rate fluctuates due to the manual water supply that produced inconsistent flow. It was also observed that the flow sensor has a duty cycle of 50% of operating time under normal condition which implies that the performance of the flow sensor is optimal.

Floods of November-December 1950 in the Central Valley basin, California

USGS Publications Warehouse

Paulsen, C.G.

1953-01-01

The flood of November-December 1950 in the Central Valley basin was the greatest in most parts of the basin since the turn of the century and probably was exceeded in the lower San Joaquin River basin only by the historic flood of 1862. In respect to monetary loss, the 1950 flood was the most disastrous in the history of the basin. Loss of life was remarkably small when one considers the extensive damage and destruction to homes and other property, which is estimated at 33 million dollars. Outstanding features of the flood were its unprecedented occurrence so early in the winter flood season, its magnitude in respect to both peak and volume in most major tributaries, and the occurrence of a succession of near-peak flows with a period of three weeks. The flood was caused by a series of storms during the period November 16 to December 8, which brought exceptionally warm, moisture-laden air inland against the Sierra Nevada range and caused intense rainfall, instead of snowfall, at unusually high altitudes. Basin-wide totals of rainfall during the period ranged from 30 inches over the Yuba and American River basins to 13 inches over the upper Sacramento and Feather River basins. Based on continuous records of discharge on major tributaries for periods ranging from 22 to 55 years and averaging about 43 years, the 1950 flood peaks were the greatest of record on the American, Cosumnes, Mokelumne, Stanislaus, Tuolumne, Merced, Chowchilla, Fresno, lower San Joaquin, Kings, Kaweah, Tule, and Kern Rivers. Second highest peak of record occurred during the flood of March 1928 on the Yuba, American and Mokelumne Rivers; the flood of Marcn 1940 on Cosumnes River; the flood of January 1911 on the Stanislaus and Tuolumne Rivers; the flood of December 1937 on the Merced, Kings, and Kaweah Rivers; the flood of March 1938 on the Chowchilla, Fresno, and lower San Joaquin Rivers; and the flood of March 1943 on the Tule and Kern Rivers. Peak discharges for 1950 did not exceed previous maxima on Bear, Yuba, Feather, and upper Sacramento Rivers, nor on west side tributaries of lower Sacramento River, Calaveras River, and upper San Joaquin River (above Friant Reservoir). Notable high rates of discharge were 354 cfs per square mile from 39.5 square miles in North Fork of Middle Fork Tule River, 225 cfs per square mile from 198 square miles in Rubicon River, 115 cfs per square mile from 999 square miles in North Fork of American River and 93.7 cfs per square mile from 1,921 square miles in American River at Fair Oaks. This report presents a general description of the 1950 flood, details and estimates of the damage incurred, records of stage and discharge for the period of the flood at 171 stream-gaging stations, records of storage in 14 reservoirs, a summary of peak discharges with comparative data for previous floods at 252 measurement points, and tables showing crest stages along the main stem and major tributary channels of the Sacramento and San Joaquin Rivers. The report also includes a discussion of meteorologic and hydrologic conditions associated with the flood, examples of the flood regulation afforded by storage reservoirs, a brief study of runoff characteristics, and a summary and comparison with previous floods in the Central Valley basin.

36 CFR 219.19 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... response to climate change. Conservation. The protection, preservation, management, or restoration of... structure and/or function and changes resources, substrate availability, or the physical environment... carbon; climate regulation; water filtration, purification, and storage; soil stabilization; flood...

36 CFR 219.19 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... response to climate change. Conservation. The protection, preservation, management, or restoration of... structure and/or function and changes resources, substrate availability, or the physical environment... carbon; climate regulation; water filtration, purification, and storage; soil stabilization; flood...

36 CFR 219.19 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... response to climate change. Conservation. The protection, preservation, management, or restoration of... structure and/or function and changes resources, substrate availability, or the physical environment... carbon; climate regulation; water filtration, purification, and storage; soil stabilization; flood...

Risk Based Reservoir Operations Using Ensemble Streamflow Predictions for Lake Mendocino in Mendocino County, California

NASA Astrophysics Data System (ADS)

Delaney, C.; Mendoza, J.; Whitin, B.; Hartman, R. K.

2017-12-01

Ensemble Forecast Operations (EFO) is a risk based approach of reservoir flood operations that incorporates ensemble streamflow predictions (ESPs) made by NOAA's California-Nevada River Forecast Center (CNRFC). With the EFO approach, each member of an ESP is individually modeled to forecast system conditions and calculate risk of reaching critical operational thresholds. Reservoir release decisions are computed which seek to manage forecasted risk to established risk tolerance levels. A water management model was developed for Lake Mendocino, a 111,000 acre-foot reservoir located near Ukiah, California, to evaluate the viability of the EFO alternative to improve water supply reliability but not increase downstream flood risk. Lake Mendocino is a dual use reservoir, which is owned and operated for flood control by the United States Army Corps of Engineers and is operated for water supply by the Sonoma County Water Agency. Due to recent changes in the operations of an upstream hydroelectric facility, this reservoir has suffered from water supply reliability issues since 2007. The EFO alternative was simulated using a 26-year (1985-2010) ESP hindcast generated by the CNRFC, which approximates flow forecasts for 61 ensemble members for a 15-day horizon. Model simulation results of the EFO alternative demonstrate a 36% increase in median end of water year (September 30) storage levels over existing operations. Additionally, model results show no increase in occurrence of flows above flood stage for points downstream of Lake Mendocino. This investigation demonstrates that the EFO alternative may be a viable approach for managing Lake Mendocino for multiple purposes (water supply, flood mitigation, ecosystems) and warrants further investigation through additional modeling and analysis.

33 CFR 239.7 - Separation of flood control works from urban drainage.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Separation of flood control works... OF THE ARMY, DEPARTMENT OF DEFENSE WATER RESOURCES POLICIES AND AUTHORITIES: FEDERAL PARTICIPATION IN COVERED FLOOD CONTROL CHANNELS § 239.7 Separation of flood control works from urban drainage. Covered...

Record Flood-Producing Rainstorms of 17-18 July 1996 in the Chicago Metropolitan Area. Part III: Impacts and Responses to the Flash Flooding.

NASA Astrophysics Data System (ADS)

Changnon, Stanley A.

1999-03-01

A record-breaking 24-h rainstorm on 17-18 July 1996 was centered on south Chicago and its southern and western suburbs, areas with a population of 3.4 million. The resulting flash flooding in Chicago and 21 suburbs broke all-time records in the region and brought the Illinois and Mississippi Rivers above flood stage. More than 4300 persons were evacuated from the flooded zones and 35000 homes experienced flood damage. Six persons were killed and the total estimated cost of the flood (losses and recovery actions) was 645 million, ranking as Illinois' second most costly weather disaster on record after the 1993 flood. Extensive damages and travel delays occurred on metropolitan transportation systems (highways and railroads). Commuters were unable to reach Chicago for up to three days and more than 300 freight trains were delayed or rerouted. Communities dealt with removal of flood-damaged materials, as well as damage to streets, bridges, and sewage treatment and water treatment plants. Reduced crop yields in adjacent rural areas represented a 67 million loss of farm income. Conflicts between communities developed over blame for the flooding due to inadequate storage capacity resulting in new regional flood planning. Federal and state aid ultimately reached 265 million, 41% of the storm costs. More than 85000 individuals received assistance, and 222 structures have been relocated under the federal Hazard Mitigation Grant Program at a cost of 19.6 million.

Performance of a system of reservoirs on futuristic front

NASA Astrophysics Data System (ADS)

Saha, Satabdi; Roy, Debasri; Mazumdar, Asis

2017-10-01

Application of simulation model HEC-5 to analyze the performance of the DVC Reservoir System (a multipurpose system with a network of five reservoirs and one barrage) on the river Damodar in Eastern India in meeting projected future demand as well as controlling flood for synthetically generated future scenario is addressed here with a view to develop an appropriate strategy for its operation. Thomas-Fiering model (based on Markov autoregressive model) has been adopted for generation of synthetic scenario (monthly streamflow series) and subsequently downscaling of modeled monthly streamflow to daily values was carried out. The performance of the system (analysed on seasonal basis) in terms of `Performance Indices' (viz., both quantity based reliability and time based reliability, mean daily deficit, average failure period, resilience and maximum vulnerability indices) for the projected scenario with enhanced demand turned out to be poor compared to that for historical scenario. However, judicious adoption of resource enhancement (marginal reallocation of reservoir storage capacity) and demand management strategy (curtailment of projected high water requirements and trading off between demands) was found to be a viable option for improvement of the performance of the reservoir system appreciably [improvement being (1-51 %), (2-35 %), (16-96 %), (25-50 %), (8-36 %) and (12-30 %) for the indices viz., quantity based reliability, time based reliability, mean daily deficit, average failure period, resilience and maximum vulnerability, respectively] compared to that with normal storage and projected demand. Again, 100 % reliability for flood control for current as well as future synthetically generated scenarios was noted. The results from the study would assist concerned authority in successful operation of reservoirs in the context of growing demand and dwindling resource.

Extreme hydrological changes in the southwestern US drive reductions in water supply to Southern California by mid century

DOE PAGES

Pagán, Brianna R.; Ashfaq, Moetasim; Rastogi, Deeksha; ...

2016-09-21

The Southwestern United States has a greater vulnerability to climate change impacts on water security due to a reliance on snowmelt driven imported water. The State of California, which is the most populous and agriculturally productive in the United States, depends on an extensive artificial water storage and conveyance system primarily for irrigated agriculture, municipal and industrial supply and hydropower generation. Here we take an integrative high-resolution ensemble approach to examine near term climate change impacts on all imported and local sources of water supply to Southern California. While annual precipitation is projected to remain the same or slightly increase,more » rising temperatures result in a shift in precipitation type towards more rainfall, reducing cold season snowpack and earlier snowmelt. Associated with these hydrological changes are substantial increases in both dry and flood event frequency and intensity. On one hand, the greater probability of drought decreases imported water supply availability. On the other hand, earlier snowmelt and significantly stronger winter precipitation events pose increased flood risk requiring water releases from reservoirs for flood control, also potentially decreasing water availability. As a result, lack of timely local water resource expansion coupled with climate change projections and population increases may leave the area in extended periods of shortages.« less

Increasing climate whiplash in 21st century California

NASA Astrophysics Data System (ADS)

Swain, D. L.; Langenbrunner, B.; Neelin, J. D.; Hall, A. D.

2017-12-01

Temperate "Mediterranean" climate regimes across the globe are particularly susceptible to wide swings between drought and flood—of which California's rapid transition from record multi-year dryness between 2012-2016 to extreme wetness during 2016-2017 provides a dramatic example. The wide-ranging human and environmental impacts of this recent "climate whiplash" event in a highly-populated, economically critical, and biodiverse region highlight the importance of understanding weather and climate extremes at both ends of the hydroclimatic spectrum. Previous studies have examined the potential contribution of anthropogenic warming to recent California extremes, but findings to date have been mixed and primarily drought-focused. Here, we use specific historical California flood and drought events as thresholds for quantifying long-term changes in precipitation extremes using a large ensemble of multi-decadal climate model simulations (CESM-LENS). We find that greenhouse gas emissions are already responsible for a detectable increase in both wet and dry extremes across portions of California, and that increasing 21st century "climate whiplash" will likely yield large increases in the frequency of both rapid "dry-to-wet" transitions and severe flood events over a wide range of timescales. This projected intensification of California's hydrological cycle would seriously challenge the region's existing water storage, conveyance, and flood control infrastructure—even absent large changes in mean precipitation.

Extreme hydrological changes in the southwestern US drive reductions in water supply to Southern California by mid century

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pagán, Brianna R.; Ashfaq, Moetasim; Rastogi, Deeksha

The Southwestern United States has a greater vulnerability to climate change impacts on water security due to a reliance on snowmelt driven imported water. The State of California, which is the most populous and agriculturally productive in the United States, depends on an extensive artificial water storage and conveyance system primarily for irrigated agriculture, municipal and industrial supply and hydropower generation. Here we take an integrative high-resolution ensemble approach to examine near term climate change impacts on all imported and local sources of water supply to Southern California. While annual precipitation is projected to remain the same or slightly increase,more » rising temperatures result in a shift in precipitation type towards more rainfall, reducing cold season snowpack and earlier snowmelt. Associated with these hydrological changes are substantial increases in both dry and flood event frequency and intensity. On one hand, the greater probability of drought decreases imported water supply availability. On the other hand, earlier snowmelt and significantly stronger winter precipitation events pose increased flood risk requiring water releases from reservoirs for flood control, also potentially decreasing water availability. As a result, lack of timely local water resource expansion coupled with climate change projections and population increases may leave the area in extended periods of shortages.« less

Real-Time Optimal Flood Control Decision Making and Risk Propagation Under Multiple Uncertainties

NASA Astrophysics Data System (ADS)

Zhu, Feilin; Zhong, Ping-An; Sun, Yimeng; Yeh, William W.-G.

2017-12-01

Multiple uncertainties exist in the optimal flood control decision-making process, presenting risks involving flood control decisions. This paper defines the main steps in optimal flood control decision making that constitute the Forecast-Optimization-Decision Making (FODM) chain. We propose a framework for supporting optimal flood control decision making under multiple uncertainties and evaluate risk propagation along the FODM chain from a holistic perspective. To deal with uncertainties, we employ stochastic models at each link of the FODM chain. We generate synthetic ensemble flood forecasts via the martingale model of forecast evolution. We then establish a multiobjective stochastic programming with recourse model for optimal flood control operation. The Pareto front under uncertainty is derived via the constraint method coupled with a two-step process. We propose a novel SMAA-TOPSIS model for stochastic multicriteria decision making. Then we propose the risk assessment model, the risk of decision-making errors and rank uncertainty degree to quantify the risk propagation process along the FODM chain. We conduct numerical experiments to investigate the effects of flood forecast uncertainty on optimal flood control decision making and risk propagation. We apply the proposed methodology to a flood control system in the Daduhe River basin in China. The results indicate that the proposed method can provide valuable risk information in each link of the FODM chain and enable risk-informed decisions with higher reliability.

CO 2 Storage and Enhanced Oil Recovery: Bald Unit Test Site, Mumford Hills Oil Field, Posey County, Indiana

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frailey, Scott M.; Krapac, Ivan G.; Damico, James R.

2012-03-30

The Midwest Geological Sequestration Consortium (MGSC) carried out a small-scale carbon dioxide (CO 2) injection test in a sandstone within the Clore Formation (Mississippian System, Chesterian Series) in order to gauge the large-scale CO 2 storage that might be realized from enhanced oil recovery (EOR) of mature Illinois Basin oil fields via miscible liquid CO 2 flooding.

The use of old cartographic datasets along with remote sensing data for better understand and map the 2005-2008 floods in Romania

NASA Astrophysics Data System (ADS)

Craciunescu, V.; Flueraru, C.; Stancalie, G.

2009-04-01

Floods are the major disaster affecting many countries in the world year after year. From Romania perspective, floods are among the most hazardous natural disasters in terms of human suffering and economic losses. Major floods occurred in 2005, 2006 and 2008, the worst ones in more than 40 years, have affected large regions of Romania: in the Timis county (April 2005) over 1 300 homes have been damaged or destroyed, 3 800 people have been evacuated and about 30 000 hectares of agricultural land flooded; in five counties situated in eastern Romania (July 2005) 11 000 homes were inundated, 8 600 people have been evacuated, 20 people were killed, 53 000 ha farmland flooded, 379 bridges damaged or destroyed; in 12 counties along the Danube (April 2006) 3 077 homes were affected (1.049 completely destroyed), 16 000 people evacuated, five people killed, 144 000 hectares of land flooded; in six counties from the North-East part of Romania (July 2008) 3 985 houses were affected (over 300 totally destroyed), 15 834 people evacuated and 35 084 hectares of agricultural land inundated. Flood management evolves and changes as more knowledge and technology becomes available to the environmental community. Satellite imagery can be very effective for flood management in detailed mapping that is required for the production of hazard assessment maps and for input to various types of hydrological models, as well as in monitoring land use/cover changes over the years to quantify prominent changes in land use/cover in general and extent of impervious area in particular. In the same time, the wealth of old cartographic documents is an important cultural and scientific heritage. By careful studying this kind of documents, a modern manager can better understand the way territory was managed in the past and the implications of that management in today's floods reality. Good quality photo cameras, flat-bed and large size scanners were used to convert the analogue old cartographic materials into digital files. Specially, highly compressed, file formats were used to reduce the raster database size without affecting the documents quality. Digitisation and online distribution of this kind of documents, via an online system, provided new ways to access and to interact with our patrimony and new tangible arguments for the flood decision makers. The research included the development of key components and modules providing characterisation (based on metadata), virtual storage, discovery and access services, including intuitive query and browsing mechanisms and exploiting the potential of semantic web and advanced storage technologies. For all the mentioned flood events various processing techniques (classification, geo-referencing, filtering, and photo-interpretation) were used to combine the optical and radar images in order to delineate the flooded areas. The resulted flood masks were integrated in GIS environment with the old cartographic database and also with digital layers that represent the current geographic reality.

Simulating on water storage and pump capacity of "Kencing" river polder system in Kudus regency, Central Java, Indonesia

NASA Astrophysics Data System (ADS)

Wahyudi, Slamet Imam; Adi, Henny Pratiwi; Santoso, Esti; Heikoop, Rick

2017-03-01

Settlement in the Jati District, Kudus Regency, Central Java Province, Indonesia, is growing rapidly. Previous paddy fields area turns into new residential, industrial and office buildings. The rain water collected in small Kencing river that flows into big Wulan River. But the current condition, during high rain intensity Wulan river water elevation higher than the Kencing river, so that water can not flow gravity and the area inundated. To reduce the flooding, required polder drainage system by providing a long channel as water storage and pumping water into Wulan river. How to get optimal value of water storage volume, drainage system channels and the pump capacity? The result used to be efficient in the operation and maintenance of the polder system. The purpose of this study is to develop some scenarios water storage volume, water gate operation and to get the optimal value of operational pumps removing water from the Kencing River to Wulan River. Research Method is conducted by some steps. The first step, it is done field orientation in detail, then collecting secondary data including maps and rainfall data. The map is processed into Watershed or catchment area, while the rainfall data is processed into runoff discharge. Furthermore, the team collects primary data by measuring topography to determine the surface and volume of water storage. The analysis conducted to determine of flood discharge, water channel hydraulics, water storage volume and pump capacity corresponding. Based on the simulating of long water storage volume and pump capacity with some scenario trying, it can be determined optimum values. The results used to be guideline in to construction proses, operation and maintenance of the drainage polder system.

MODELING PLUMES IN SMALL STREAMS

EPA Science Inventory

Pesticides accumulate on land surfaces from agricultural, commercial, and domestic application, and wash into streams and rivers during dry and wet weather. Flood water retention basins or structures often collect this contaminated runoff, providing intermediate storage and limit...

49 CFR 379.5 - Protection and storage of records.

Code of Federal Regulations, 2013 CFR

2013-10-01

... to this part from fires, floods, and other hazards, and safeguard the records from unnecessary... notify the Secretary if prescribed records are substantially destroyed or damaged before the term of the prescribed retention periods. ...

49 CFR 379.5 - Protection and storage of records.

Code of Federal Regulations, 2014 CFR

2014-10-01

... to this part from fires, floods, and other hazards, and safeguard the records from unnecessary... notify the Secretary if prescribed records are substantially destroyed or damaged before the term of the prescribed retention periods. ...

49 CFR 379.5 - Protection and storage of records.

Code of Federal Regulations, 2011 CFR

2011-10-01

... to this part from fires, floods, and other hazards, and safeguard the records from unnecessary... notify the Secretary if prescribed records are substantially destroyed or damaged before the term of the prescribed retention periods. ...

49 CFR 379.5 - Protection and storage of records.

Code of Federal Regulations, 2012 CFR

2012-10-01

... to this part from fires, floods, and other hazards, and safeguard the records from unnecessary... notify the Secretary if prescribed records are substantially destroyed or damaged before the term of the prescribed retention periods. ...

49 CFR 379.5 - Protection and storage of records.

Code of Federal Regulations, 2010 CFR

2010-10-01

... to this part from fires, floods, and other hazards, and safeguard the records from unnecessary... notify the Secretary if prescribed records are substantially destroyed or damaged before the term of the prescribed retention periods. ...

Impact of stream restoration on flood waves

NASA Astrophysics Data System (ADS)

Sholtes, J.; Doyle, M.

2008-12-01

Restoration of channelized or incised streams has the potential to reduce downstream flooding via storing and dissipating the energy of flood waves. Restoration design elements such as restoring meanders, reducing slope, restoring floodplain connectivity, re-introducing in-channel woody debris, and re-vegetating banks and the floodplain have the capacity to attenuate flood waves via energy dissipation and channel and floodplain storage. Flood discharge hydrographs measured up and downstream of several restored reaches of varying stream order and located in both urban and rural catchments are coupled with direct measurements of stream roughness at various stages to directly measure changes to peak discharge, flood wave celerity, and dispersion. A one-dimensional unsteady flow routing model, HEC-RAS, is calibrated and used to compare attenuation characteristics between pre and post restoration conditions. Modeled sensitivity results indicate that a restoration project placed on a smaller order stream demonstrates the highest relative reduction in peak discharge of routed flood waves compared to one of equal length on a higher order stream. Reductions in bed slope, extensions in channel length, and increases in channel and floodplain roughness follow restoration placement with the watershed in relative importance. By better understanding how design, scale, and location of restored reaches within a catchment hydraulically impact flood flows, this study contributes both to restoration design and site decision making. It also quantifies the effect of reach scale stream restoration on flood wave attenuation.

Application of satellite radar altimetry for near-real time monitoring of floods

NASA Astrophysics Data System (ADS)

Lee, H.; Calmant, S.; Shum, C.; Kim, J.; Huang, Z.; Bettadpur, S. V.; Alsdorf, D. E.

2011-12-01

According to the 2004 UNESCO World Disasters Report, it is estimated that flooding affected 116 million people globally, causing about 7000 deaths and leading to $7.5 billion in losses. The report also indicates that flood is the most frequently occurring disaster type among all other natural disasters. Hence, timely monitoring of changing of river, wetland and lake/reservoir levels is important to support disaster monitoring and proper response. Yet, we have surprisingly poor knowledge of the spatial and temporal dynamics of surface water discharge and storage changes globally. Although satellite radar altimetry has been successfully used to observe water height changes over rivers, lakes, reservoirs, and wetlands, there have been few studies for near-real time monitoring of floods mainly due to its limited spatial and temporal sampling of surface water elevations. In this study, we monitor flood by examining its spatial and temporal origin of the flooding and its timely propagation using multiple altimeter-river intersections over the entire hydrologic basin. We apply our method to the Amazon 2009 flood event that caused the most severe flooding in more than two decades. We also compare our results with inundated areas estimated from ALOS PALSAR ScanSAR measurements and GRACE 15-day Quick-Look (QL) gravity field data product. Our developed method would potentially enhance the capability of satellite altimeter toward near-real time monitoring of floods and mitigating their hazards.

Hydrometeorological network for flood monitoring and modeling

NASA Astrophysics Data System (ADS)

Efstratiadis, Andreas; Koussis, Antonis D.; Lykoudis, Spyros; Koukouvinos, Antonis; Christofides, Antonis; Karavokiros, George; Kappos, Nikos; Mamassis, Nikos; Koutsoyiannis, Demetris

2013-08-01

Due to its highly fragmented geomorphology, Greece comprises hundreds of small- to medium-size hydrological basins, in which often the terrain is fairly steep and the streamflow regime ephemeral. These are typically affected by flash floods, occasionally causing severe damages. Yet, the vast majority of them lack flow-gauging infrastructure providing systematic hydrometric data at fine time scales. This has obvious impacts on the quality and reliability of flood studies, which typically use simplistic approaches for ungauged basins that do not consider local peculiarities in sufficient detail. In order to provide a consistent framework for flood design and to ensure realistic predictions of the flood risk -a key issue of the 2007/60/EC Directive- it is essential to improve the monitoring infrastructures by taking advantage of modern technologies for remote control and data management. In this context and in the research project DEUCALION, we have recently installed and are operating, in four pilot river basins, a telemetry-based hydro-meteorological network that comprises automatic stations and is linked to and supported by relevant software. The hydrometric stations measure stage, using 50-kHz ultrasonic pulses or piezometric sensors, or both stage (piezometric) and velocity via acoustic Doppler radar; all measurements are being temperature-corrected. The meteorological stations record air temperature, pressure, relative humidity, wind speed and direction, and precipitation. Data transfer is made via GPRS or mobile telephony modems. The monitoring network is supported by a web-based application for storage, visualization and management of geographical and hydro-meteorological data (ENHYDRIS), a software tool for data analysis and processing (HYDROGNOMON), as well as an advanced model for flood simulation (HYDROGEIOS). The recorded hydro-meteorological observations are accessible over the Internet through the www-application. The system is operational and its functionality has been implemented as open-source software for use in a wide range of applications in the field of water resources monitoring and management, such as the demonstration case study outlined in this work.

Managing Floodplain Expectations on the Lower Missouri River, USA.

NASA Astrophysics Data System (ADS)

Bulliner, E. A., IV; Jacobson, R. B.; Lindner, G. A.; Paukert, C.; Bouska, K.

2017-12-01

The Missouri River is an archetype of the challenges of managing large rivers and their floodplains for multiple objectives. At 1.3 million km2 drainage area, the Missouri boasts the largest reservoir system in North America with 91 km3 of total storage; in an average year the system generates 10 billion kilowatt hours of electricity. The Lower Missouri River floodplain extends 1,300 km downstream from the reservoir system and encompasses approximately 9,200 km2. For the past 150 years, the floodplain has been predominantly used for agriculture much of which is protected from flooding by private and Federal levees. Reservoir system operating policies prioritize flood-hazard reduction but in recent years, large, damaging floods have demonstrated system limitations. These large floods and changing societal values have created new expectations about how conversion of floodplain agricultural lands to conservation lands might increase ecosystem services, in particular decreasing flood risk and mitigating fluxes of nutrients to the Gulf of Mexico. Our research addresses these expectations at multiple spatial scales by starting with hydrologic and hydraulic models to understand controls on floodplain hydrodynamics. The results document the substantial regional spatial variability in floodplain connectivity that exists because of multi-decadal channel adjustments to channelization and sediment budgets. Exploration of levee setback scenarios with 1- and 2-dimensional hydrodynamic models indicates modest and spatially variable gains in flood-hazard reduction are possible if substantial land areas (50% or more) are converted from agricultural production. Estimates of potential denitrification benefits of connecting floodplains indicate that the floodplain has the capacity to remove 100's to 1,000's of metric tons of N each year, but amounts to a maximum of about 5% the existing load of 200,000 ton*y-1. The results indicate that in this river-floodplain system, the ecosystem services associated with floodplain conversion can be substantial, but the sum of benefits needed to justify land conversion over broad areas remains uncertain.

33 CFR 209.300 - Flood control regulations.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Flood control regulations. 209..., DEPARTMENT OF DEFENSE ADMINISTRATIVE PROCEDURE § 209.300 Flood control regulations. (a) Regulations for the operation and maintenance of local flood protection works approved by the Secretary of the Army under the...

A New Approach to Flood Protection Design and Riparian Management

Treesearch

Philip B. Williams; Mitchell L. Swanson

1989-01-01

Conventional engineering methods of flood control design focus narrowly on the efficient conveyance of water, with little regard for environmental resource planning and natural geomorphic processes. Consequently, flood control projects are often environmentally disastrous, expensive to maintain, and even inadequate to control floods. In addition, maintenance programs...

Safety in the Chemical Laboratory: Flood Control.

ERIC Educational Resources Information Center

Pollard, Bruce D.

1983-01-01

Describes events leading to a flood in the Wehr Chemistry Laboratory at Marquette University, discussing steps taken to minimize damage upon discovery. Analyzes the problem of flooding in the chemical laboratory and outlines seven steps of flood control: prevention; minimization; early detection; stopping the flood; evaluation; clean-up; and…

Coupled hydrologic and hydraulic modeling of Upper Niger River Basin

NASA Astrophysics Data System (ADS)

Fleischmann, Ayan; Siqueira, Vinícius; Paris, Adrien; Collischonn, Walter; Paiva, Rodrigo; Gossett, Marielle; Pontes, Paulo; Calmant, Stephane; Biancamaria, Sylvain; Crétaux, Jean-François; Tanimoune, Bachir

2017-04-01

The Upper Niger Basin is located in Western Africa, flowing from Guinea Highlands towards the Sahel region. In this area lies the seasonally inundated Niger Inland Delta, which supports important environmental services such as habitats for wildlife, climate and flood regulation, as well as large fishery and agricultural areas. In this study, we present the application of MGB-IPH large scale hydrologic and hydrodynamic model for the Upper Niger Basin, totaling c.a. 650,000 km2 and set up until the city of Niamey in Niger. The model couples hydrological vertical balance and runoff generation with hydrodynamic flood wave propagation, by allowing infiltration from floodplains into soil column as well as representing backwater effects and floodplain storage throughout flat areas such as the Inland Delta. The model is forced with TRMM 3B42 daily precipitation and Climate Research Unit (CRU) climatology for the period 2000-2010, and was calibrated against in-situ discharge gauges and validated with in-situ water level, remotely sensed estimations of flooded areas (classification of MODIS imagery) and satellite altimetry (JASON-2 mission). Model results show good predictions for calibrated daily discharge and validated water level and altimetry at stations both upstream and downstream of the delta (Nash-Sutcliffe Efficiency>0.7 for all stations), as well as for flooded areas within the delta region (ENS=0.5; r2=0.8), allowing a good representation of flooding dynamics basinwide and simulation of flooding behavior of both perennial (e.g., Niger main stem) and ephemeral rivers (e.g., Niger Red Flood tributaries in Sahel). Coupling between hydrology and hydrodynamic processes indicates an important feedback between floodplain and soil water storage that allows high evapotranspiration rates even after the flood passage around the inner delta area. Also, representation of water retention in floodplain channels and distributaries in the inner delta (e.g., Diaka river distributary) is fundamental for the correct representation of the flood wave attenuation in Niger main stem. Improvements could be made in terms of floods propagation across the basin -through parameters such as Manning's roughness and section depth and width-using the comparison with satellite altimetry data, for instance. Finally, such coupled hydrologic and hydrodynamic models prove to be an important tool for integrated evaluation of hydrological processes in such ungauged, large scale floodplain areas. Possible uses of the model involve the assessment of different scenarios of anthropic alteration, e.g., the effects of reservoirs implementation and climate and land use changes.

The role of water and sediment connectivity in integrated flood management: a case study on the island of Saint Lucia

NASA Astrophysics Data System (ADS)

Jetten, Victor; van Westen, Cees; Ettema, Janneke; van den Bout, Bastian

2016-04-01

Disaster Risk Management combines the effects of natural hazards in time and space, with elements at risk, such as ourselves, infrastructure or other elements that have a value in our society. The risk in this case is defined as the sum of potential consequences of one or more hazards and can be expressed as potential damages. Generally, we attempt to reduce risk by better risk management, such as increase of resilience, protection and spatial planning. Caribbean islands are hit by hurricanes and tropical storms with a frequency of 1 to 2 every 10 years, with devastating consequences in terms of flash floods and landslides. The islands basically consist of a central (volcanic) mountain range, with medium and small sized catchments radiating outward towards the ocean. The coastal zone is inhabited, while the ring road network is essential for functioning of the island. An example of a case study is given for the island of Saint Lucia. Recorded rainfall intensities during tropical storms of 12 rainfall stations surpass 200 mm/h, causing immediate flash floods. Very often however, sediment is a forgotten variable in flash flood management: protection and mitigation measures as well as spatial planning all focus on the hydrology, the extent and depth of flood water, and sometimes of flood velocities. With recent developments, the opensource model LISEM includes hydrology and runoff, flooding, and erosion, transport and deposition both in runoff, channel flow and flood waters. We will discuss the practical solutions we implemented in connecting slopes, river channels and floodplains in terms of water and sediment, and the strength and weaknesses we have encountered so far. Catchment analysis shows two main effects: on the one hand in almost all cases upstream flooding serves as a temporary water storage that prevents further damage downstream, while on the other hand, erosion upstream often blocks bridges and decreases channel storage downstream, which increases the flood potential considerably during the event, and if not cleared properly during the next event. To understand this it is essential to simulate the catchment as one integrated unit, study connectivity and sources and sinks. We will show how from these simulations, how sustainable hazard and risk reduction strategies can be derived. The example comes from the Worldbank technical assistance project CHARIM, that is currently conducted by the University of Twente (the Netherlands), University of Bristol, (UK) and the University of the West Indies (Trinidad and Tobago) in 4 Caribbean islands and Belize.

Modelling the effects of Prairie wetlands on streamflow

NASA Astrophysics Data System (ADS)

Shook, K.; Pomeroy, J. W.

2015-12-01

Recent research has demonstrated that the contributing areas of Prairie streams dominated by depressional (wetland) storage demonstrate hysteresis with respect to catchment water storage. As such contributing fractions can vary over time from a very small percentage of catchment area to the entire catchment during floods. However, catchments display complex memories of past storage states and their contributing fractions cannot be modelled accurately by any single-valued function. The Cold Regions Hydrological Modelling platform, CRHM, which is capable of modelling all of the hydrological processes of cold regions using a hydrological response unit discretization of the catchment, was used to further investigate dynamical contributing area response to hydrological processes. Contributing fraction in CRHM is also controlled by the episodic nature of runoff generation in this cold, sub-humid environment where runoff is dominated by snowmelt over frozen soils, snowdrifts define the contributing fraction in late spring, unfrozen soils have high water holding capacity and baseflow from sub-surface flow does not exist. CRHM was improved by adding a conceptual model of individual Prairie depression fill and spill runoff generation that displays hysteresis in the storage - contributing fraction relationship and memory of storage state. The contributing area estimated by CRHM shows strong sensitivity to hydrological inputs, storage and the threshold runoff rate chosen. The response of the contributing area to inputs from various runoff generating processes from snowmelt to rain-on-snow to rainfall with differing degrees of spatial variation was investigated as was the importance of the memory of storage states on streamflow generation. The importance of selecting hydrologically and ecologically meaningful runoff thresholds in estimating contributing area is emphasized.

Floods and Fluvial Wood

NASA Astrophysics Data System (ADS)

Comiti, F.

2014-12-01

Several studies have recently addressed the complex interactions existing at various spatial scales among riparian vegetation, channel morphology and wood storage. The majority of these investigations has been carried out in relatively natural river systems, focusing mostly on the long-term vegetation-morphology dynamics under "equilibrium" conditions. Little is still known about the role of flood events - of different frequency/magnitude - on several aspects of such dynamics, e.g. entrainment conditions of in-channel wood, erosion rates of vegetation from channel margins and from islands, transport distances of wood elements of different size along the channel network. Even less understood is how the river's evolutionary trajectory may affect these processes, and thus the degree to which conceptual models derivable from near-natural systems could be applicable to human-disturbed channels. Indeed, the different human pressures - present on most river basins worldwide - have greatly impaired the morphological and ecological functions of fluvial wood, and the attempts to "restore" in-channel wood storage are currently carried out without a sufficient understanding of wood transport processes occurring during floods. On the other hand, the capability to correctly predict the magnitude of large wood transport during large floods is now seen as crucial - especially in mountain basins - for flood hazard mapping, as is the identification of the potential wood sources (e.g. landslides, floodplains, islands) for the implementation of sound and effective hazard mitigation measures. The presentation will first summarize the current knowledge on fluvial wood dynamics and modelling at different spatial and temporal scales, with a particular focus on mountain rivers. The effects of floods of different characteristics on vegetation erosion and wood transport will be then addressed presenting some study cases from rivers in the European Alps and in the Italian Apennines featuring different degrees of human alteration. Finally, several conclusions about the applicability of wood transport modelling and on rationale vegetation/wood management strategies will be drawn.

1D and 2D urban dam-break flood modelling in Istanbul, Turkey

NASA Astrophysics Data System (ADS)

Ozdemir, Hasan; Neal, Jeffrey; Bates, Paul; Döker, Fatih

2014-05-01

Urban flood events are increasing in frequency and severity as a consequence of several factors such as reduced infiltration capacities due to continued watershed development, increased construction in flood prone areas due to population growth, the possible amplification of rainfall intensity due to climate change, sea level rise which threatens coastal development, and poorly engineered flood control infrastructure (Gallegos et al., 2009). These factors will contribute to increased urban flood risk in the future, and as a result improved modelling of urban flooding according to different causative factor has been identified as a research priority (Gallegos et al., 2009; Ozdemir et al. 2013). The flooding disaster caused by dam failures is always a threat against lives and properties especially in urban environments. Therefore, the prediction of dynamics of dam-break flows plays a vital role in the forecast and evaluation of flooding disasters, and is of long-standing interest for researchers. Flooding occurred on the Ayamama River (Istanbul-Turkey) due to high intensity rainfall and dam-breaching of Ata Pond in 9th September 2009. The settlements, industrial areas and transportation system on the floodplain of the Ayamama River were inundated. Therefore, 32 people were dead and millions of Euros economic loses were occurred. The aim of this study is 1 and 2-Dimensional flood modelling of the Ata Pond breaching using HEC-RAS and LISFLOOD-Roe models and comparison of the model results using the real flood extent. The HEC-RAS model solves the full 1-D Saint Venant equations for unsteady open channel flow whereas LISFLOOD-Roe is the 2-D shallow water model which calculates the flow according to the complete Saint Venant formulation (Villanueva and Wright, 2006; Neal et al., 2011). The model consists a shock capturing Godunov-type scheme based on the Roe Riemann solver (Roe, 1981). 3 m high resolution Digital Surface Model (DSM), natural characteristics of the pond and its breaching such as depth, wide, length, volume and breaching shape and daily total rainfall data were used in the models. The simulated flooding in the both models were compared with the real flood extent which gathered from photos taken after the flood event, high satellite images acquired after 20 days from the flood event, and field works. The results show that LISFLOOD-Roe hydraulic model gives more than 80% fit to the extent of real flood event. Also both modelling results show that the embankment breaching of the Ata Pond directly affected the flood magnitude and intensity on the area. This study reveals that modelling of the probable flooding in urban areas is necessary and very important in urban planning. References Gallegos, H. A., Schubert, J. E., and Sanders, B. F.: Two dimensional, high-resolution modeling of urban dam-break flooding: A case study of Baldwin Hills California, Adv. Water Resour., 32, 1323-1335, 2009. Neal, J., Villanueva, I., Wright, N., Willis, T., Fewtrell, T. and Bates, P.: How mush physical complexity is needed to model flood inundation? Hydrological Processes, DOI: 10.1002/hyp.8339. Ozdemir H., Sampson C., De Almeida G., Bates P.D.: Evaluating scale and roughness effects in urban flood modelling using terrestrial LiDAR data, Hydrology and Earth System Sciences, vol.17, pp.4015-4030, 2013. Roe P.: Approximate Riemann solvers, parameter vectors, and difference-schemes. Journal of Computational Physics 43(2): 357-372, 1981. Villanueva I, Wright NG.: Linking Riemann and storage cell models for flood prediction. Proceedings of the Institution of Civil Engineers, Journal of Water Management 159: 27-33, 2006.

33 CFR 203.42 - Inspection of non-Federal flood control works.

Code of Federal Regulations, 2011 CFR

2011-07-01

... PROCEDURES Rehabilitation Assistance for Flood Control Works Damaged by Flood or Coastal Storm: The Corps... standards and is capable of providing the intended degree of flood protection. An Acceptable or Minimally...

Demonstration of a conceptual model for using LiDAR to improve the estimation of floodwater mitigation potential of Prairie Pothole Region wetlands

USGS Publications Warehouse

Huang, S.; Young, Caitlin; Feng, M.; Heidemann, Hans Karl; Cushing, Matthew; Mushet, D.M.; Liu, S.

2011-01-01

Recent flood events in the Prairie Pothole Region of North America have stimulated interest in modeling water storage capacities of wetlands and their surrounding catchments to facilitate flood mitigation efforts. Accurate estimates of basin storage capacities have been hampered by a lack of high-resolution elevation data. In this paper, we developed a 0.5 m bare-earth model from Light Detection And Ranging (LiDAR) data and, in combination with National Wetlands Inventory data, delineated wetland catchments and their spilling points within a 196 km2 study area. We then calculated the maximum water storage capacity of individual basins and modeled the connectivity among these basins. When compared to field survey results, catchment and spilling point delineations from the LiDAR bare-earth model captured subtle landscape features very well. Of the 11 modeled spilling points, 10 matched field survey spilling points. The comparison between observed and modeled maximum water storage had an R2 of 0.87 with mean absolute error of 5564 m3. Since maximum water storage capacity of basins does not translate into floodwater regulation capability, we further developed a Basin Floodwater Regulation Index. Based upon this index, the absolute and relative water that could be held by wetlands over a landscape could be modeled. This conceptual model of floodwater downstream contribution was demonstrated with water level data from 17 May 2008.

Influence of Groundwater Hydraulic Gradient on Bank Storage Metrics.

PubMed

Welch, Chani; Harrington, Glenn A; Cook, Peter G

2015-01-01

The hydraulic gradient between aquifers and rivers is one of the most variable properties in a river/aquifer system. Detailed process understanding of bank storage under hydraulic gradients is obtained from a two-dimensional numerical model of a variably saturated aquifer slice perpendicular to a river. Exchange between the river and the aquifer occurs first at the interface with the unsaturated zone. The proportion of total water exchanged through the river bank compared to the river bed is a function of aquifer hydraulic conductivity, partial penetration, and hydraulic gradient. Total exchange may be estimated to within 50% using existing analytical solutions provided that unsaturated zone processes do not strongly influence exchange. Model-calculated bank storage is at a maximum when no hydraulic gradient is present and increases as the hydraulic conductivity increases. However, in the presence of a hydraulic gradient, the largest exchange flux or distance of penetration does not necessarily correspond to the highest hydraulic conductivity, as high hydraulic conductivity increases the components of exchange both into and out of an aquifer. Flood wave characteristics do not influence ambient groundwater discharge, and so in large floods, hydraulic gradients must be high to reduce the volume of bank storage. Practical measurement of bank storage metrics is problematic due to the limitations of available measurement technologies and the nested processes of exchange that occur at the river-aquifer interface. Proxies, such as time series concentration data in rivers and groundwater, require further development to be representative and quantitative. © 2014, National GroundWater Association.

Flood risk analysis for flood control and sediment transportation: a case study in the catchments of the Loess Plateau, China

NASA Astrophysics Data System (ADS)

Wang, Y.; Chang, J.; Guo, A.

2017-12-01

Traditional flood risk analysis focuses on the probability of flood events exceeding the design flood of downstream hydraulic structures while neglecting the influence of sedimentation in river channels on flood control systems. Given this focus, a univariate and copula-based bivariate hydrological risk framework focusing on flood control and sediment transport is proposed in the current work. Additionally, the conditional probabilities of occurrence of different flood events under various extreme precipitation scenarios are estimated by exploiting the copula model. Moreover, a Monte Carlo-based algorithm is used to evaluate the uncertainties of univariate and bivariate hydrological risk. Two catchments located on the Loess plateau are selected as study regions: the upper catchments of the Xianyang and Huaxian stations (denoted as UCX and UCH, respectively). The results indicate that (1) 2-day and 3-day consecutive rainfall are highly correlated with the annual maximum flood discharge (AMF) in UCX and UCH, respectively; and (2) univariate and bivariate return periods, risk and reliability for the purposes of flood control and sediment transport are successfully estimated. Sedimentation triggers higher risks of damaging the safety of local flood control systems compared with the AMF, exceeding the design flood of downstream hydraulic structures in the UCX and UCH. Most importantly, there was considerable sampling uncertainty in the univariate and bivariate hydrologic risk analysis, which would greatly challenge measures of future flood mitigation. The proposed hydrological risk framework offers a promising technical reference for flood risk analysis in sandy regions worldwide.

Hydrology

USGS Publications Warehouse

Eisenbies, Mark H.; Hughes, W. Brian

2000-01-01

Hydrologic process are the main determinants of the type of wetland located on a site. Precipitation, groundwater, or flooding interact with soil properties and geomorphic setting to yield a complex matrix of conditions that control groundwater flux, water storage and discharge, water chemistry, biotic productivity, biodiversity, and biogeochemical cycling. Hydroperiod affects many abiotic factors that in turn determine plant and animal species composition, biodiversity, primary and secondary productivity, accumulation, of organic matter, and nutrient cycling. Because the hydrologic regime has a major influence on wetland functioning, understanding how hydrologic changes influence ecosystem processes is essential, especially in light of the pressures placed on remaining wetlands by society's demands for water resources and by potential global changes in climate.

10 CFR 50.68 - Criticality accident requirements.

Code of Federal Regulations, 2012 CFR

2012-01-01

... boron is taken, the k-effective of the spent fuel storage racks loaded with fuel of the maximum fuel... flooded with unborated water. If credit is taken for soluble boron, the k-effective of the spent fuel...

10 CFR 50.68 - Criticality accident requirements.

Code of Federal Regulations, 2014 CFR

2014-01-01

... boron is taken, the k-effective of the spent fuel storage racks loaded with fuel of the maximum fuel... flooded with unborated water. If credit is taken for soluble boron, the k-effective of the spent fuel...

10 CFR 50.68 - Criticality accident requirements.

Code of Federal Regulations, 2013 CFR

2013-01-01

... boron is taken, the k-effective of the spent fuel storage racks loaded with fuel of the maximum fuel... flooded with unborated water. If credit is taken for soluble boron, the k-effective of the spent fuel...

10 CFR 50.68 - Criticality accident requirements.

Code of Federal Regulations, 2011 CFR

2011-01-01

... boron is taken, the k-effective of the spent fuel storage racks loaded with fuel of the maximum fuel... flooded with unborated water. If credit is taken for soluble boron, the k-effective of the spent fuel...

10 CFR 50.68 - Criticality accident requirements.

Code of Federal Regulations, 2010 CFR

2010-01-01

... boron is taken, the k-effective of the spent fuel storage racks loaded with fuel of the maximum fuel... flooded with unborated water. If credit is taken for soluble boron, the k-effective of the spent fuel...

Hydrogeomorphology of the hyporheic zone: stream solute and fine particle interactions with a dynamic streambed

USGS Publications Warehouse

Harvey, J.W.; Drummond, J.D.; Martin, R.L.; McPhillips, L.E.; Packman, A.I.; Jerolmack, D.J.; Stonedahl, S.H.; Aubeneau, A.F.; Sawyer, A.H.; Larsen, L.G.; Tobias, C.R.

2012-01-01

Hyporheic flow in streams has typically been studied separately from geomorphic processes. We investigated interactions between bed mobility and dynamic hyporheic storage of solutes and fine particles in a sand-bed stream before, during, and after a flood. A conservatively transported solute tracer (bromide) and a fine particles tracer (5 μm latex particles), a surrogate for fine particulate organic matter, were co-injected during base flow. The tracers were differentially stored, with fine particles penetrating more shallowly in hyporheic flow and retained more efficiently due to the high rate of particle filtration in bed sediment compared to solute. Tracer injections lasted 3.5 h after which we released a small flood from an upstream dam one hour later. Due to shallower storage in the bed, fine particles were rapidly entrained during the rising limb of the flood hydrograph. Rather than being flushed by the flood, we observed that solutes were stored longer due to expansion of hyporheic flow paths beneath the temporarily enlarged bedforms. Three important timescales determined the fate of solutes and fine particles: (1) flood duration, (2) relaxation time of flood-enlarged bedforms back to base flow dimensions, and (3) resulting adjustments and lag times of hyporheic flow. Recurrent transitions between these timescales explain why we observed a peak accumulation of natural particulate organic matter between 2 and 4 cm deep in the bed, i.e., below the scour layer of mobile bedforms but above the maximum depth of particle filtration in hyporheic flow paths. Thus, physical interactions between bed mobility and hyporheic transport influence how organic matter is stored in the bed and how long it is retained, which affects decomposition rate and metabolism of this southeastern Coastal Plain stream. In summary we found that dynamic interactions between hyporheic flow, bed mobility, and flow variation had strong but differential influences on base flow retention and flood mobilization of solutes and fine particulates. These hydrogeomorphic relationships have implications for microbial respiration of organic matter, carbon and nutrient cycling, and fate of contaminants in streams.

Snow mass and river flows modelled using GRACE total water storage observations

NASA Astrophysics Data System (ADS)

Wang, S.

2017-12-01

Snow mass and river flow measurements are difficult and less accurate in cold regions due to the hash environment. Floods in cold regions are commonly a result of snowmelt during the spring break-up. Flooding is projected to increase with climate change in many parts of the world. Forecasting floods from snowmelt remains a challenge due to scarce and quality issues in basin-scale snow observations and lack of knowledge for cold region hydrological processes. This study developed a model for estimating basin-level snow mass (snow water equivalent SWE) and river flows using the total water storage (TWS) observations from the Gravity Recovery and Climate Experiment (GRACE) satellite mission. The SWE estimation is based on mass balance approach which is independent of in situ snow gauge observations, thus largely eliminates the limitations and uncertainties with traditional in situ or remote sensing snow estimates. The model forecasts river flows by simulating surface runoff from snowmelt and the corresponding baseflow from groundwater discharge. Snowmelt is predicted using a temperature index model. Baseflow is predicted using a modified linear reservoir model. The model also quantifies the hysteresis between the snowmelt and the streamflow rates, or the lump time for water travel in the basin. The model was applied to the Red River Basin, the Mackenzie River Basin, and the Hudson Bay Lowland Basins in Canada. The predicted river flows were compared with the observed values at downstream hydrometric stations. The results were also compared to that for the Lower Fraser River obtained in a separate study to help better understand the roles of environmental factors in determining flood and their variations with different hydroclimatic conditions. This study advances the applications of space-based time-variable gravity measurements in cold region snow mass estimation, river flow and flood forecasting. It demonstrates a relatively simple method that only needs GRACE TWS and temperature data for river flow or flood forecasting. The model can be particularly useful for regions with spare observation networks, and can be used in combination with other available methods to help improve the accuracy in river flow and flood forecasting over cold regions.

The influence of flood frequency, riparian vegetation and threshold on long-term river transport capacity

NASA Astrophysics Data System (ADS)

Croissant, Thomas; Lague, Dimitri; Davy, Philippe

2016-04-01

Climate fluctuations at geological timescales control the capacity of rivers to transport sediment with consequences on geochemical cycles, sedimentary basins dynamics and sedimentation/tectonics interactions. While the impact of differential friction generated by riparian vegetation has been studied for individual flood events, its impact on the long-term sediment transport capacity of rivers, modulated by the frequency of floods remains unknown. Here, we investigate this effect on a simplified river-floodplain configuration obeying observed hydraulic scaling laws. We numerically integrate the full-frequency magnitude distribution of discharge events and its impact on the transport capacity of bedload and suspended material for various level of vegetation-linked differential friction. We demonstrate that riparian vegetation by acting as a virtual confinement of the flow i) increases significantly the instantaneous transport capacity of the river independently of the transport mode and ii) increases the long term bedload transport rates as a function of discharge variability. Our results expose the dominance of flood frequency rather than riparian vegetation on the long term sediment transport capacity. Therefore, flood frequency has to be considered when evaluating long-term bedload transport capacity while floodplain vegetation is important only in high discharge variability regimes. By comparing the transport capacity of unconfined alluvial rivers and confined bedrock gorges, we demonstrate that the latter always presents the highest long term transport capacity at equivalent width and slope. The loss of confinement at the transition between bedrock and alluvial river must be compensated by a widening or a steepening of the alluvial channel to avoid infinite storage. Because steepening is never observed in natural system, we compute the alluvial widening factor value that varies between 3 to 11 times the width of the bedrock channel depending on riparian vegetation and discharge variability. This result is well supported by measurements made in natural river systems in different worldwide locations (Taiwan, Himalayas and New Zealand). Although bank cohesion is often invoked to as a property that sets alluvial river width, we propose unconfinement as another important control factor.

Water exchange and pressure transfer between conduits and matrix and their influence on hydrodynamics of two karst aquifers with sinking streams

NASA Astrophysics Data System (ADS)

Bailly-Comte, Vincent; Martin, Jonathan B.; Jourde, Hervé; Screaton, Elizabeth J.; Pistre, Séverin; Langston, Abigail

2010-05-01

SummaryKarst aquifers are heterogeneous media where conduits usually drain water from lower permeability volumes (matrix and fractures). For more than a century, various approaches have used flood recession curves, which integrate all hydrodynamic processes in a karst aquifer, to infer physical properties of the movement and storage of groundwater. These investigations typically only consider flow to the conduits and thus have lacked quantitative observations of how pressure transfer and water exchange between matrix and conduit during flooding could influence recession curves. We present analyses of simultaneous discharge and water level time series of two distinctly different karst systems, one with low porosity and permeability matrix rocks in southern France, and one with high porosity and permeability matrix rocks in north-central Florida (USA). We apply simple mathematical models of flood recession using time series representations of recharge, storage, and discharge processes in the karst aquifer. We show that karst spring hydrographs can be interpreted according to pressure transfer between two distinct components of the aquifer, conduit and matrix porosity, which induce two distinct responses at the spring. Water exchange between conduits and matrix porosity successively control the flow regime at the spring. This exchange is governed by hydraulic head differences between conduits and matrix, head gradients within conduits, and the contrast of permeability between conduits and matrix. These observations have consequences for physical interpretations of recession curves and modeling of karst spring flows, particularly for the relative magnitudes of base flow and quick flow from karst springs. Finally, these results suggest that similar analyses of recession curves can be applied to karst aquifers with distinct physical characteristics utilizing well and spring hydrograph data, but information must be known about the hydrodynamics and physical properties of the aquifer before the results can be correctly interpreted.

The influence of major dams on hydrology through the drainage network of the Sacramento River basin, California

USGS Publications Warehouse

Singer, M.B.

2007-01-01

This paper reports basinwide patterns of hydrograph alteration via statistical and graphical analysis from a network of long-term streamflow gauges located various distances downstream of major dams and confluences in the Sacramento River basin in California, USA. Streamflow data from 10 gauging stations downstream of major dams were divided into hydrologic series corresponding to the periods before and after dam construction. Pre- and post-dam flows were compared with respect to hydrograph characteristics representing frequency, magnitude and shape: annual flood peak, annual flow trough, annual flood volume, time to flood peak, flood drawdown time and interarrival time. The use of such a suite of characteristics within a statistical and graphical framework allows for generalising distinct strategies of flood control operation that can be identified without any a priori knowledge of operations rules. Dam operation is highly dependent on the ratio of reservoir capacity to annual flood volume (impounded runoff index). Dams with high values of this index generally completely cut off flood peaks thus reducing time to peak, drawdown time and annual flood volume. Those with low values conduct early and late flow releases to extend the hydrograph, increasing time to peak, drawdown time and annual flood volume. The analyses reveal minimal flood control benefits from foothill dams in the lower Sacramento River (i.e. dissipation of the down-valley flood control signal). The lower part of the basin is instead reliant on a weir and bypass system to control lowland flooding. Data from a control gauge (i.e. with no upstream dams) suggest a background signature of global climate change expressed as shortened flood hydrograph falling limbs and lengthened flood interarrival times at low exceedence probabilities. This research has implications for flood control, water resource management, aquatic and riparian ecosystems and for rehabilitation strategies involving flow alteration and/or manipulation of sediment supplies. Copyright ?? 2006 John Wiley & Sons, Ltd.

Contributions of GRACE to Understanding of Spatial Distribution of Spring Flooding in Snow-dominated Afghan Watersheds

NASA Astrophysics Data System (ADS)

Roningen, J. M.; Daly, S. F.; Vuyovich, C.

2012-12-01

In Afghanistan, where both historical and current in situ hydrologic records are extremely limited, the development and stability operations communities require guidance as to how to best utilize capabilities in remote sensing of the water cycle to understand and predict seasonal flooding. In this study, three versions of Level 3 GRACE datasets (CSR, CSR 4.1 and GRGS) are compared to TRMM 3B42 products, SSM/I-derived snow water equivalent products (SWE), and MODIS-derived flooding extents to assess their potential for contributing to an understanding of the spatial and temporal patterns of spring flooding in Afghanistan from the period 2002-2012. GRACE, which allows for assessment of correlations between small-scale temporal changes in the gravitational field of the earth with changes in the total water storage in the hydrosphere, opens the possibility for incorporation of subsurface components of the hydrologic cycle into remote monitoring and modeling of water resources. GRACE data exhibit clear seasonal fluctuations in many areas of Afghanistan, but an assessment is required of the extent to which this data can be disaggregated spatially and related to geographic patterns of precipitation, snowmelt and flooding. In this study, TRMM 3B42 and SSM/I-derived SWE datasets were used as proxies for measured precipitation. These datasets were convolved with a Gaussian filter with a 300 km half-radius at each reported GRACE data point in order to compensate for spatial correlation ('leakage' effects) in the GRACE data. In mountainous and snowmelt-dominated basins such as the majority of those in this study, GRACE analyses that make use of land surface model (LSM) derived estimates may not provide adequate characterization of snow water equivalent and soil moisture in this region. Therefore, soil and subsurface moisture were evaluated as a single storage component using the GRACE data, and flooding occurrence was evaluated as a qualitative surface expression of this storage component. Initial results show that cumulative Gaussian-smoothed TRMM data correlate positively with GRACE CSR during the periods between yearly GRACE minima and maxima at points throughout most watersheds. The timing of peaks in GRACE data in central Afghanistan following the onset of the seasonal SWE decline also corresponds to seasonal rises in the nearby Kajakai Reservoir as measured by Jason-2 satellite altimetry and validated by manual records. Differences between datasets also appear to confirm the irregularities introduced in this region by the CSR 4.1 product that used a land surface model in the signal restoration process.

Lake Storage Measurements For Water Resources Management: Combining Remotely Sensed Water Levels and Surface Areas

NASA Astrophysics Data System (ADS)

Brakenridge, G. R.; Birkett, C. M.

2013-12-01

Presently operating satellite-based radar altimeters have the ability to monitor variations in surface water height for large lakes and reservoirs, and future sensors will expand observational capabilities to many smaller water bodies. Such remote sensing provides objective, independent information where in situ data are lacking or access is restricted. A USDA/NASA (http://www.pecad.fas.usda.gov/cropexplorer/global_reservoir/) program is performing operational altimetric monitoring of the largest lakes and reservoirs around the world using data from the NASA/CNES, NRL, and ESA missions. Public lake-level products from the Global Reservoir and Lake Monitor (GRLM) are a combination of archived and near real time information. The USDA/FAS utilizes the products for assessing international irrigation potential and for crop production estimates; other end-users study climate trends, observe anthropogenic effects, and/or are are involved in other water resources management and regional water security issues. At the same time, the Dartmouth Flood Observatory (http://floodobservatory.colorado.edu/), its NASA GSFC partners (http://oas.gsfc.nasa.gov/floodmap/home.html), and associated MODIS data and automated processing algorithms are providing public access to a growing GIS record of the Earth's changing surface water extent, including changes related to floods and droughts. The Observatory's web site also provide both archival and near real time information, and is based mainly on the highest spatial resolution (250 m) MODIS bands. Therefore, it is now possible to provide on an international basis reservoir and lake storage change measurements entirely from remote sensing, on a frequently updating basis. The volume change values are based on standard numerical procedures used for many decades for analysis of coeval lake area and height data. We provide first results of this combination, including prototype displays for public access and data retrieval of water storage volume changes. Ground-based data can, in some cases, test the remote sensing accuracy and precision. Data accuracy requirements vary for different applications: reservoir management for flood control, agriculture, or power generation may need more accurate and timely information than (for example) regional assessments of water and food security issues. Thus, the long-term goal for the hydrological sciences community should be to efficiently mesh both types of information and with as extensive geographic coverage as possible.

Spatio-temporal effects of low impact development practices

NASA Astrophysics Data System (ADS)

Gilroy, Kristin L.; McCuen, Richard H.

2009-04-01

SummaryThe increase in land development and urbanization experienced in the US and worldwide is causing environmental degradation. Traditional off-site stormwater management does not protect small streams. To mitigate the negative effects of land development, best management practices (BMPs) are being implemented into stormwater management policies for the purposes of controlling minor flooding and improving water quality. Unfortunately, the effectiveness of BMPs has not been extensively studied. The purpose of this research was to analyze the effects of both location and quantity of two types of BMPs: cisterns and bioretention pits. A spatio-temporal model of a microwatershed was developed to determine the effects of BMPs on single-family, townhome, and commercial lots. The effects of development and the BMPs on peak runoff rates and volumes were compared to pre-development conditions. The results show that cisterns alone are capable of controlling rooftop runoff for small storms. Both the spatial location and the volume of BMP storage on a microwatershed influences the effectiveness of BMPs. The volume of BMP storage is positively correlated to the percent reduction in the peak discharge rate and total runoff volume; however, location is a factor in the peak reduction and a maximum volume of effective storage for both hydrologic metrics does exist. These results provide guidelines for developing stormwater management policies that can potentially reduce pollution of first-order streams, lower the cost and maintenance requirements, enhance aesthetics, and increase safety.

Relationship between Dongting Lake and surrounding rivers under the operation of the Three Gorges Reservoir, China.

PubMed

Zhan, Lucheng; Chen, Jiansheng; Zhang, Shiyin; Huang, Dewen; Li, Ling

2015-01-01

The natural flow properties of the Yangtze River have been changed completely following the construction of the Three Gorges Dam. The dam's operation has affected the resources and environment in the middle and lower reaches of the Yangtze River, changing the hydrological conditions and ecological environment of the Dongting Lake. During three different dispatching periods of the reservoir, we took triplicate samples of the river and lake water. All the samples were analysed for δ(2)H and δ(18)O to determine the relationship between the lake and the Yangtze River (and other rivers), and to evaluate objectively the influence of the dam's operation on the lake. During the period of water-supply dispatch, the Four Rivers and Miluo River are the main recharge sources of the lake. During the flood-storage dispatching period, the Dongting Lake is recharged largely by the Three Outlets and the Four Rivers, whereas during the period of water-storage dispatch, most of the lake's water originates from the Miluo, Xiang, Zi, and Yuan rivers. Although the Yangtze River only contributes significantly to the lake's recharge through the Three Outlets during the flood-storage dispatching period, the lake discharges large amounts of water into the Yangtze River during all three periods. Through the operation of the reservoir, it should be ensured that the water level of the Dongting Lake is not too low during the dry season, nor too high during the wet season, thus preventing the lake region from future flood and drought disasters.

Experimental Floods in a Time of Drought: The 2014 Pulse Flow in the Lower Colorado River, Arizona, USA, and Mexico

NASA Astrophysics Data System (ADS)

Kennedy, J.; Ramirez-Hernandez, J.; Ramirez, J.

2015-12-01

In March and April, 2014, an unprecedented experimental "pulse flow" with a total volume of over 100 million cubic meters (81,000 acre-feet) of water was released from Morelos Dam into the normally dry lower Colorado River below Yuma, Arizona, for the primary purpose of restoring native vegetation and habitat. Significant infiltration and attenuation of the flood peak occurred within the limitrophe reach that forms the US-Mexico border, with total volume reduced to 57 million cubic meters at the southerly international boundary at San Luis Rio Colorado, Sonora, Mexico (32 kilometers downstream). Groundwater levels in piezometers adjacent to the stream channel rose as much as 10 meters, and surface water/groundwater connection was established throughout the reach, despite depths-to-water greater than 15 meters prior to the pulse flow. Based on groundwater levels, a groundwater mound remained in the vicinity of the stream channel for several months but had largely dissipated into the regional groundwater system by fall 2014. Ultimately, a large amount of water was moved from storage in an upstream reservoir (Lake Mead), where it is potentially available to many users but where evaporation losses can be high, to the regional aquifer in the Yuma-Mexicali area, where the water could be available to local users but cannot be precisely quantified as it moves through the groundwater system. During a time of drought, tradeoffs between local vs. upstream storage, and reservoir vs. subsurface storage, will likely be increasingly important considerations in planning future experimental floods on the Colorado River.

Ex post damage assessment: an Italian experience

NASA Astrophysics Data System (ADS)

Molinari, D.; Menoni, S.; Aronica, G. T.; Ballio, F.; Berni, N.; Pandolfo, C.; Stelluti, M.; Minucci, G.

2014-04-01

In recent years, awareness of a need for more effective disaster data collection, storage, and sharing of analyses has developed in many parts of the world. In line with this advance, Italian local authorities have expressed the need for enhanced methods and procedures for post-event damage assessment in order to obtain data that can serve numerous purposes: to create a reliable and consistent database on the basis of which damage models can be defined or validated; and to supply a comprehensive scenario of flooding impacts according to which priorities can be identified during the emergency and recovery phase, and the compensation due to citizens from insurers or local authorities can be established. This paper studies this context, and describes ongoing activities in the Umbria and Sicily regions of Italy intended to identifying new tools and procedures for flood damage data surveys and storage in the aftermath of floods. In the first part of the paper, the current procedures for data gathering in Italy are analysed. The analysis shows that the available knowledge does not enable the definition or validation of damage curves, as information is poor, fragmented, and inconsistent. A new procedure for data collection and storage is therefore proposed. The entire analysis was carried out at a local level for the residential and commercial sectors only. The objective of the next steps for the research in the short term will be (i) to extend the procedure to other types of damage, and (ii) to make the procedure operational with the Italian Civil Protection system. The long-term aim is to develop specific depth-damage curves for Italian contexts.

Disastrous torrential floods in mountain areas in Serbia

NASA Astrophysics Data System (ADS)

Gavrilovic, Z.

2009-04-01

In Serbia, the relief is predominantly hilly and mountainous, intersected with numerous rivers. The greatest number of watercourses are small torrents; however the proportionally large rivers also have a distinctive torrential character. The highest parts of the catchments are at the altitudes above 1500 m, while their confluences are at the altitudes of 200 - 300 m. The catchment and channel slopes are extremely steep. So, as the initial natural preconditions are satisfied, torrential floods are the consequence. Although the Južna Morava catchments were regulated by erosion control works, during the last decades there were numerous torrential floods. Some of the floods had disastrous proportions, not recorded in Serbia or in Europe. The flood of river Vlasina in 1988 was presented to the professional public several times. This flood was not an isolated case. Many large-scale torrential floods occurred in Serbia from 1994 to 2007. As there were floods also in 2007, the causes of the recorded floods had to be analysed. The analysis pointed out a series of scenarios which were the causes of disastrous torrential floods, and also the disadvantages of the actual system of torrent and erosion control. Special attention was focused on the floods which resulted from sudden snow melting. This paper will present the results of the analyses of the extreme torrential floods of the rivers Nišava and Vlasina. Key words: Flood, torrents, torrent control, erosion control

Magnitude and frequency of floods in the United States, Part 3-A, Ohio River Basin except Cumberland and Tennessee River Basins

USGS Publications Warehouse

Speer, Paul R.; Gamble, Charles R.

1965-01-01

This report presents a means of determining the probable magnitude and frequency of floods of any recurrence interval from 1.1 to 50 years at most points on streams in the Ohio River basin except Cumberland and Tennessee River basins. Curves are defined that show the relation between the drainage area and the mean annual flood in eight hydrologic areas, and composite frequency curves define the relation of a flood of any recurrence interval from 1.1 to 50 years to the mean annual flood. These two relations are based upon gaging-station records having 10 or more years of record not materially affected by storage or diversion, and the results obtainable from them will represent the magnitude and frequency of natural floods within the range and recurrence intervals defined by the base data. The report also contains a compilation of flood records at all sites in the area at which records have been collected for 5 or more consecutive years. As far as was possible at each location for which discharge has been determined, the tabulations include all floods above a selected base. Where only gage heights have been obtained or where the data did not warrant computation of peach discharges above a selected base, only annual peaks are shown. The maximum known flood discharges for the streamflow stations and miscellaneous points except Ohio River main stem stations, together with areal floods of 10- and 50-year recurrence intervals, are plotted against the size of drainage area for each flood region and hydrologic area to provide a convenient means of judging the frequency of the maximum known floods that have been recorded for these points.

Multi-temporal flood mapping and satellite altimetry used to evaluate the flood dynamics of the Bolivian Amazon wetlands

NASA Astrophysics Data System (ADS)

Ovando, A.; Martinez, J. M.; Tomasella, J.; Rodriguez, D. A.; von Randow, C.

2018-07-01

The Bolivian Amazon wetlands are extensive floodplains distributed over the Mamore, Beni, Madre de Dios and Guapore Rivers. Located within the upper Madeira River Basin, the wetlands play important roles in regulating the biogeochemical processes and hydrological cycle of the region. In addition, they have major ecological and hydrological relevance for the entire Amazon Basin. These wetlands are characterized by the occurrence of episodic floods that result from contrasting hydro-meteorological processes in the Andean Mountain region, the piedmont area and the Amazon lowlands. In this study, we characterized the flood dynamics of the region using multi-temporal flood mapping based on optical altimetry (MODIS - Moderate Resolution Imaging Spectroradiometer - M*D09A1) and satellite altimetry (ENVISAT RA-2 and SARAL AltiKa altimeters). This study provides new insights regarding the frequency, magnitude and spatial distribution of exogenous floods, which are created by flood waves from the Andes; and endogenous floods, which result from runoff originating in the lowlands. The maximum extent of flooding during 2001-2014 was 43144 km2 in the Mamore Basin and 34852 km2 in the Guapore Basin, and the total surface water storage in these floodplains reached 94 km3. The regionalization of flood regimes based on water stage time series signatures allowed those regions that are exposed to frequent floods, which are generally located along rivers without a direct connection with the Andes, to be distinguished from floodplains that are more dependent on flood waves originating in the Andes and its piedmonts. This information is of great importance for understanding the roles of these wetlands in the provision of ecosystem services.

Earth Observations taken by Expedition 30 crewmember

NASA Image and Video Library

2011-12-03

ISS030-E-009186 (3 Dec. 2011) --- The Menindee Lakes, New South Wales, Australia are featured in this image photographed by an Expedition 30 crew member on the International Space Station. The Menindee Lakes comprise a system of ephemeral, freshwater lakes fed by the Darling River when it floods. The lakes lie in the far west of New South Wales, Australia, near the town of Menindee. The longest is Lake Tandou (18.6 kilometers north?south dimension), visible at the upper right of this photograph. The lakes appear to have a small amount of water flooding them. The Darling River itself was flowing, as indicated by the dark water and blackened mud along its course (left). The Darling River flows southwest in tortuous fashion (bottom left to upper right). In the flat landscapes of this part of Australia, the river has created several inland deltas in its course to the sea, with characteristic diverging channel patterns, marked by younger sediments, which appear grayer than the surrounding ancient red soils and rocks. One such inland delta appears at right where minor channels wind across the countryside. The apex of another inland delta appears at upper right. Some of the Menindee Lakes have been incorporated in an artificially regulated overflow system providing for flood control, water storage for domestic use and livestock, as well as downstream irrigation. The lakes are also important as wetlands supporting a rich diversity of birds. The floor of one lake, Lake Tandou, is also used as prime agricultural land, as can be seen by its patchwork of irrigated fields, and is protected from flooding.

Estimating floodwater depths from flood inundation maps and topography

USGS Publications Warehouse

Cohen, Sagy; Brakenridge, G. Robert; Kettner, Albert; Bates, Bradford; Nelson, Jonathan M.; McDonald, Richard R.; Huang, Yu-Fen; Munasinghe, Dinuke; Zhang, Jiaqi

2018-01-01

Information on flood inundation extent is important for understanding societal exposure, water storage volumes, flood wave attenuation, future flood hazard, and other variables. A number of organizations now provide flood inundation maps based on satellite remote sensing. These data products can efficiently and accurately provide the areal extent of a flood event, but do not provide floodwater depth, an important attribute for first responders and damage assessment. Here we present a new methodology and a GIS-based tool, the Floodwater Depth Estimation Tool (FwDET), for estimating floodwater depth based solely on an inundation map and a digital elevation model (DEM). We compare the FwDET results against water depth maps derived from hydraulic simulation of two flood events, a large-scale event for which we use medium resolution input layer (10 m) and a small-scale event for which we use a high-resolution (LiDAR; 1 m) input. Further testing is performed for two inundation maps with a number of challenging features that include a narrow valley, a large reservoir, and an urban setting. The results show FwDET can accurately calculate floodwater depth for diverse flooding scenarios but also leads to considerable bias in locations where the inundation extent does not align well with the DEM. In these locations, manual adjustment or higher spatial resolution input is required.

Modulation of Extreme Flood Levels by Impoundment Significantly Offset by Floodplain Loss Downstream of the Three Gorges Dam

NASA Astrophysics Data System (ADS)

Mei, Xuefei; Dai, Zhijun; Darby, Stephen E.; Gao, Shu; Wang, Jie; Jiang, Weiguo

2018-04-01

River flooding—the world's most significant natural hazard—is likely to increase under anthropogenic climate change. Most large rivers have been regulated by damming, but the extent to which these impoundments can mitigate extreme flooding remains uncertain. Here the catastrophic 2016 flood on the Changjiang River is first analyzed to assess the effects of both the Changjiang's reservoir cascade and the Three Gorges Dam (TGD), the world's largest hydraulic engineering project on downstream flood discharge and water levels. We show that the Changjiang's reservoir cascade impounded over 30.0 × 103 m3/s of flow at the peak of the flood on 25 July 2016, preventing the occurrence of what would otherwise have been the second largest flood ever recorded in the reach downstream of the TGD. Half of this flood water storage was retained by the TGD alone, meaning that impoundment by the TGD reduced peak water levels at the Datong hydrometric station (on 25 July) by 1.47 m, compared to pre-TGD conditions. However, downstream morphological changes, in particular, extensive erosion of the natural floodplain, offset this reduction in water level by 0.22 m, so that the full beneficial impact of floodwater retention by the TGD was not fully realized. Our results highlight how morphological adjustments downstream of large dams may inhibit their full potential to mitigate extreme flood risk.

24 CFR 581.6 - Suitability criteria.

Code of Federal Regulations, 2010 CFR

2010-04-01

..., the property will not be determined unsuitable on this basis. (2) Property containing flammable or... handling flammable or explosive material (excluding underground storage) will be determined unsuitable..., friable asbestos, PCB's, or natural hazardous substances such as radon, periodic flooding, sinkholes or...

Impact of intertidal area characteristics on estuarine tidal hydrodynamics: A modelling study for the Scheldt Estuary

NASA Astrophysics Data System (ADS)

Stark, J.; Smolders, S.; Meire, P.; Temmerman, S.

2017-11-01

Marsh restoration projects are nowadays being implemented as ecosystem-based strategies to reduce flood risks and to restore intertidal habitat along estuaries. Changes in estuarine tidal hydrodynamics are expected along with such intertidal area changes. A validated hydrodynamic model of the Scheldt Estuary is used to gain fundamental insights in the role of intertidal area characteristics on tidal hydrodynamics and tidal asymmetry in particular through several geomorphological scenarios in which intertidal area elevation and location along the estuary is varied. Model results indicate that the location of intertidal areas and their storage volume relative to the local tidal prism determine the intensity and reach along the estuary over which tidal hydrodynamics are affected. Our model results also suggest that intertidal storage areas that are located within the main estuarine channel system, and hence are part of the flow-carrying part of the estuary, may affect tidal hydrodynamics differently than intertidal areas that are side-basins of the main estuarine channel, and hence only contribute little to the flow-carrying cross-section of the estuary. If tidal flats contribute to the channel cross-section and exert frictional effects on the tidal propagation, the elevation of intertidal flats influences the magnitude and direction of tidal asymmetry along estuarine channels. Ebb-dominance is most strongly enhanced if tidal flats are around mean sea level or slightly above. Conversely, flood-dominance is enhanced if the tidal flats are situated low in the tidal frame. For intertidal storage areas at specific locations besides the main channel, flood-dominance in the estuary channel peaks in the vicinity of those areas and generally reduces upstream and downstream compared to a reference scenario. Finally, the model results indicate an along-estuary varying impact on the tidal prism as a result of adding intertidal storage at a specific location. In addition to known effects of tidal prism decrease upstream and tidal prism increase downstream of additional storage areas, our model results indicate a reduction in tidal prism far downstream of intertidal storage areas as a result of a decreasing tidal range. This study may assist estuarine managers in assessing the impact of marsh restoration and managed shoreline realignment projects, as well as with the morphological management of estuaries through dredging and disposal of sediment on intertidal areas.

Climate, orography and scale controls on flood frequency in Triveneto (Italy)

NASA Astrophysics Data System (ADS)

Persiano, Simone; Castellarin, Attilio; Salinas, Jose Luis; Domeneghetti, Alessio; Brath, Armando

2016-05-01

The growing concern about the possible effects of climate change on flood frequency regime is leading Authorities to review previously proposed reference procedures for design-flood estimation, such as national flood frequency models. Our study focuses on Triveneto, a broad geographical region in North-eastern Italy. A reference procedure for design flood estimation in Triveneto is available from the Italian NCR research project "VA.PI.", which considered Triveneto as a single homogeneous region and developed a regional model using annual maximum series (AMS) of peak discharges that were collected up to the 1980s by the former Italian Hydrometeorological Service. We consider a very detailed AMS database that we recently compiled for 76 catchments located in Triveneto. All 76 study catchments are characterized in terms of several geomorphologic and climatic descriptors. The objective of our study is threefold: (1) to inspect climatic and scale controls on flood frequency regime; (2) to verify the possible presence of changes in flood frequency regime by looking at changes in time of regional L-moments of annual maximum floods; (3) to develop an updated reference procedure for design flood estimation in Triveneto by using a focused-pooling approach (i.e. Region of Influence, RoI). Our study leads to the following conclusions: (1) climatic and scale controls on flood frequency regime in Triveneto are similar to the controls that were recently found in Europe; (2) a single year characterized by extreme floods can have a remarkable influence on regional flood frequency models and analyses for detecting possible changes in flood frequency regime; (3) no significant change was detected in the flood frequency regime, yet an update of the existing reference procedure for design flood estimation is highly recommended and we propose the RoI approach for properly representing climate and scale controls on flood frequency in Triveneto, which cannot be regarded as a single homogeneous region.

A Comprehensive Study of the Tocks Island Lake Project and Alternatives. Part A. Chapters I, II, III. Analysis of Service Areas and Resource Needs.

DTIC Science & Technology

1975-06-01

Conventional Hydroelectric and Pumped Storage Power XI- 49 2. Electric Power Demand XI- 53 3. Water Demand by Power Plants XI- 54 4. Fossil and Nuclear ...Systems and Temporary Evacuation XV- 32 12. Upstream Land Use and Agricultural Treatment XV- 32 13. Results and Criteria for Further Analysis XV- 33... resulted in record flows and significant flooding. The August, 1955, flood was a result of Hurricanes Connie and Diane. Northern New Jersey streams have had

Madison River, Montana Report on Flood Emergency Madison River Slide. Volume 1. Main Report

DTIC Science & Technology

1960-09-01

SUbject The Earthquake Madison River Valley Hebgen Dam and Lake Madison R1 ver Slide MADISOX RIVlm1 IIOIT.ANA :REPORT 01’ FLOOD l!MBRGDCY...the Gallatin River on the east and the Jefferson River on the west to form the Missouri Rivero See the general map Plate lo Hebgen Dam ~ a water...storage project of the Mont&Da Power Company:; is located at the entrance to Madison Canyon in the Madison Mountain RSDge o From the dam , the river flows

Basin-Scale Reconstruction of Flood Characteristics in a Small Urban Waterhsed

NASA Astrophysics Data System (ADS)

Miller, A. J.; Smith, J. A.; Baeck, M. L.

2006-05-01

Intense short-duration summer thunderstorms are primarily responsible for the occurrence of extreme floods in small, highly urban watersheds. In these systems hydrologic response is rapid and the role of urban infrastructure (impervious cover, storm drain networks, stormwater retention facilities, engineered channels, road embankments, bridges and culverts, and floodplain fill and regrading) has potentially important consequences for runoff generation and for flood-wave propagation. The occurrence of even a single well- documented extreme event provides an opportunity to improve our understanding of the relationships between temporal and spatial patterns of precipitation, natural and anthropogenic landscape features, and the dynamics of flood behavior. We report on combined field and modeling studies of a record flood (Qpk ~ 250 m3s-1) that occurred on 7 July 2004 in the 14.3 km2 Dead Run watershed in suburban Baltimore, Maryland. Flood peaks were reconstructed for nine locations in the watershed and streamflow hydrographs were derived for four locations where complete or partial stage records were recovered; these were compared with precipitation mass-balance estimates using bias-corrected radar rainfall data in order to examine the spatial pattern of runoff ratios, lag times, and cumulative properties of the flood wave as it advanced downstream. Flood behavior in part reflects the role of capacity constraints in the storm drain network and of ponding and storage of overbank flow by physical barriers such as road embankments and culverts. The results can be used to improve predictions of flood response to other hydrometeorological events and provide insight on sensitivity of flood behavior to patterns of urban development and infrastructure.

Flood-inundation and flood-mitigation modeling of the West Branch Wapsinonoc Creek Watershed in West Branch, Iowa

USGS Publications Warehouse

Cigrand, Charles V.

2018-03-26

The U.S. Geological Survey (USGS) in cooperation with the city of West Branch and the Herbert Hoover National Historic Site of the National Park Service assessed flood-mitigation scenarios within the West Branch Wapsinonoc Creek watershed. The scenarios are intended to demonstrate several means of decreasing peak streamflows and improving the conveyance of overbank flows from the West Branch Wapsinonoc Creek and its tributary Hoover Creek where they flow through the city and the Herbert Hoover National Historic Site located within the city.Hydrologic and hydraulic models of the watershed were constructed to assess the flood-mitigation scenarios. To accomplish this, the models used the U.S. Army Corps of Engineers Hydrologic Engineering Center-Hydrologic Modeling System (HEC–HMS) version 4.2 to simulate the amount of runoff and streamflow produced from single rain events. The Hydrologic Engineering Center-River Analysis System (HEC–RAS) version 5.0 was then used to construct an unsteady-state model that may be used for routing streamflows, mapping areas that may be inundated during floods, and simulating the effects of different measures taken to decrease the effects of floods on people and infrastructure.Both models were calibrated to three historic rainfall events that produced peak streamflows ranging between the 2-year and 10-year flood-frequency recurrence intervals at the USGS streamgage (05464942) on Hoover Creek. The historic rainfall events were calibrated by using data from two USGS streamgages along with surveyed high-water marks from one of the events. The calibrated HEC–HMS model was then used to simulate streamflows from design rainfall events of 24-hour duration ranging from a 20-percent to a 1-percent annual exceedance probability. These simulated streamflows were incorporated into the HEC–RAS model.The unsteady-state HEC–RAS model was calibrated to represent existing conditions within the watershed. HEC–RAS model simulations with the existing conditions and streamflows from the design rainfall events were then done to serve as a baseline for evaluating flood-mitigation scenarios. After these simulations were completed, three different flood-mitigation scenarios were developed with HEC–RAS: a detention-storage scenario, a conveyance improvement scenario, and a combination of both. In the detention-storage scenario, four in-channel detention structures were placed upstream from the city of West Branch to attenuate peak streamflows. To investigate possible improvements to conveying floodwaters through the city of West Branch, a section of abandoned railroad embankment and an old truss bridge were removed in the model, because these structures were producing backwater areas during flooding events. The third scenario combines the detention and conveyance scenarios so their joint efficiency could be evaluated. The scenarios with the design rainfall events were run in the HEC–RAS model so their flood-mitigation effects could be analyzed across a wide range of flood magnitudes.

Evaluating the placement and performance of nature based measures for managing flood runoff in intensively farmed landscapes

NASA Astrophysics Data System (ADS)

Wilkinson, Mark; Quinn, Paul; Hewett, Caspar; Stutter, Marc

2017-04-01

Over the past decade economic losses from fluvial floods have greatly increased and it is becoming less viable to use traditional measures for managing flooding solely. This has given rise to increasing interest in alternative, nature based solutions (NBS) for reducing flood risk that aim to manage runoff at the catchment source and deliver multiple benefits. In many cases these measures need to work with current agricultural practices. Intensive agriculture often results in increases in local runoff rates, water quality issues, soil erosion/loss and local flooding problems. However, there is potential for agriculture to play a part in reducing flood risk. This requires knowledge on the effectiveness of NBS at varying scales and tools to communicate the risk of runoff associated with farming. This paper assesses the placement, management and effectiveness of a selection of nature-based measures in the rural landscape. Measures which disconnect overland flow pathways and improve soil infiltration are discussed. Case study examples are presented from the UK where a large number of nature-based measures have been constructed as part of flood protection schemes in catchment scales varying from 50 ha to 25 km2. Practical tools to help locate measures in agricultural landscapes are highlighted including the Floods and Agriculture Risk Matrix (FARM), an interactive communication/visualization tool and FARMPLOT, a GIS mapping tool. These have been used to promote such measures, by showing how and where temporary ponded areas can be located to reduce flood and erosion risk whilst minimising disruption to farming practices. In most cases land managers prefer small ( 100-1000m3) temporary ponding areas which fill during moderate to large storm events since they incur minimal loss of land. They also provide greater resillience to multi-day storm events, as they are designed to drain over 1-2 days and therefore allow for storage capacity for proceeding events. However, the performance of isolated temporary storage areas can be limited during extreme events. At larger scales taking a treatment train approach using a network of measures has been shown to achieve greater benefits, e.g. by reducing local flood peaks and capturing sediments. Current local scale evidence presented here has been used to inform environmental policy on the correct placement and design of flood reduction measures. Further long term data collection is required to assess the larger scale impact of these measures. These data can be used to inform scenario-based modelling approaches. By holding and attenuating runoff in rural landscapes, benefits for local flood peak reduction, water quality improvement and sediment management can be achieved. However, there is still a need to examine the sustainability of such measures through long term environmental payment schemes, considering how they could be funded across generational timescales rather than political cycles, and to monitor these measures over longer timescales and in multiple settings.

Floods of November 1978 to March 1979 in Arizona and west-central New Mexico

USGS Publications Warehouse

Aldridge, B.N.; Hales, T.A.

1983-01-01

Widespread rainfall of 3 to 9 inches in the mountains area of Arizona and West-Central New Mexico during December 17-20, 1978, caused maximum known discharges on the Gila River in New Mexico and on several streams in Arizona. At Phoenix, the Salt River was the highest since 1920 but was only slightly higher than the flood in March 1978. The Agua Fria River was the highest since 1919. The floods caused 12 deaths and more than $150 million in damage. Damage of $51.8 million occurred in Maricopa County, Arizona. Ten counties in Arizona and three counties in New Mexico wer declared disaster areas. Unusually high volumes of runoff occurred on the Salt, Verde, and Agua Fria Rivers upstream from reservoirs. Overflow from the reservoir systems caused flooding downstream. Storage in the reservoirs on the Salt and Verde River reduced the peak discharge of the Salt River at Phoenix from a potential of about 234,000 cubic feet per second to 126,00 cubic feet per second and greatly reduced the duration of the flood. (USGS)

Hydrologic and Hydraulic Analyses of Selected Streams in Lorain County, Ohio, 2003

USGS Publications Warehouse

Jackson, K. Scott; Ostheimer, Chad J.; Whitehead, Matthew T.

2003-01-01

Hydrologic and hydraulic analyses were done for selected reaches of nine streams in Lorain County Ohio. To assess the alternatives for flood-damage mitigation, the Lorain County Engineer and the U.S. Geological Survey (USGS) initiated a cooperative study to investigate aspects of the hydrology and hydraulics of the nine streams. Historical streamflow data and regional regression equations were used to estimate instantaneous peak discharges for floods having recurrence intervals of 2, 5, 10, 25, 50, and 100 years. Explanatory variables used in the regression equations were drainage area, main-channel slope, and storage area. Drainage areas of the nine stream reaches studied ranged from 1.80 to 19.3 square miles. The step-backwater model HEC-RAS was used to determine water-surface-elevation profiles for the 10-year-recurrence-interval (10-year) flood along a selected reach of each stream. The water-surface pro-file information was used then to generate digital mapping of flood-plain boundaries. The analyses indicate that at the 10-year flood elevation, road overflow results at numerous hydraulic structures along the nine streams.

Interannual kinetics (2010-2013) of large wood in a river corridor exposed to a 50-year flood event and fluvial ice dynamics

NASA Astrophysics Data System (ADS)

Boivin, Maxime; Buffin-Bélanger, Thomas; Piégay, Hervé

2017-02-01

Semi-alluvial rivers of the Gaspé Peninsula, Québec, are prone to produce and transport vast quantities of large wood (LW). The high rate of lateral erosion owing to high energy flows and noncohesive banks is the main process leading to the recruitment of large wood, which in turn initiates complex patterns of wood accumulation and reentrainment within the active channel. The delta of the Saint-Jean River (SJR) has accumulated large annual wood fluxes since 1960 that culminated in a wood raft of > 3-km in length in 2014. To document the kinetics of large wood on the main channel of SJR, four annual surveys were carried out from 2010 to 2013 to locate and describe > 1000 large wood jams (LWJ) and 2000 large wood individuals (LWI) along a 60-km river section. Airborne and ground photo/video images were used to estimate the wood volume introduced by lateral erosion and to identify local geomorphic conditions that control wood mobility and deposits. Video camera analysis allowed the examination of transport rates from three hydrometeorological events for specific river sections. Results indicate that the volume of LW recruited between 2010 and 2013 represents 57% of the total LW production over the 2004-2013 period. Volumes of wood deposited along the 60-km section were four times higher in 2013 than in 2010. Increases in wood amount occurred mainly in upper alluvial sections of the river, whereas decreases were observed in the semi-alluvial middle sections. Observations suggest that the 50-year flood event of 2010 produced large amounts of LW that were only partly exported out of the basin so that a significant amount was still available for subsequent floods. Large wood storage continued after this flood until a similar flood or an ice-breakup event could remobilise these LW accumulations into the river corridor. Ice-jam floods transport large amounts of wood during events with fairly low flow but do not contribute significantly to recruitment rates (ca. 10 to 30% early). It is fairly probable that the wood export peak observed in 2012 at the river mouth, where no flood occurred and which is similar to the 1-in 10-year flood of 2010, is mainly linked to such ice-break events that occurred in March 2012.

33 CFR 209.220 - Flood control regulations.

Code of Federal Regulations, 2010 CFR

2010-07-01

... the purpose of coordinating the operation of the flood control features of reservoirs constructed... responsible for the maintenance and operation of the reservoir involved after a detailed study of the flood.... Regulations prescribed by the Secretary of the Army for the maintenance and operation of local flood...

33 CFR 209.220 - Flood control regulations.

Code of Federal Regulations, 2011 CFR

2011-07-01

... the purpose of coordinating the operation of the flood control features of reservoirs constructed... responsible for the maintenance and operation of the reservoir involved after a detailed study of the flood.... Regulations prescribed by the Secretary of the Army for the maintenance and operation of local flood...

Near Real-Time Flood Monitoring and Impact Assessment Systems. Chapter 6; [Case Study: 2011 Flooding in Southeast Asia

NASA Technical Reports Server (NTRS)

Ahamed, Aakash; Bolten, John; Doyle, Colin; Fayne, Jessica

2016-01-01

Floods are the costliest natural disaster, causing approximately 6.8 million deaths in the twentieth century alone. Worldwide economic flood damage estimates in 2012 exceed $19 Billion USD. Extended duration floods also pose longer term threats to food security, water, sanitation, hygiene, and community livelihoods, particularly in developing countries. Projections by the Intergovernmental Panel on Climate Change (IPCC) suggest that precipitation extremes, rainfall intensity, storm intensity, and variability are increasing due to climate change. Increasing hydrologic uncertainty will likely lead to unprecedented extreme flood events. As such, there is a vital need to enhance and further develop traditional techniques used to rapidly assess flooding and extend analytical methods to estimate impacted population and infrastructure. Measuring flood extent in situ is generally impractical, time consuming, and can be inaccurate. Remotely sensed imagery acquired from space-borne and airborne sensors provides a viable platform for consistent and rapid wall-to-wall monitoring of large flood events through time. Terabytes of freely available satellite imagery are made available online each day by NASA, ESA, and other international space research institutions. Advances in cloud computing and data storage technologies allow researchers to leverage these satellite data and apply analytical methods at scale. Repeat-survey earth observations help provide insight about how natural phenomena change through time, including the progression and recession of floodwaters. In recent years, cloud-penetrating radar remote sensing techniques (e.g., Synthetic Aperture Radar) and high temporal resolution imagery platforms (e.g., MODIS and its 1-day return period), along with high performance computing infrastructure, have enabled significant advances in software systems that provide flood warning, assessments, and hazard reduction potential. By incorporating social and economic data, researchers can develop systems that automatically quantify the socioeconomic impacts resulting from flood disaster events.

Extreme Mississippi River Floods in the Late Holocene: Reconstructions and Simulations

NASA Astrophysics Data System (ADS)

Munoz, S. E.; Giosan, L.; Donnelly, J. P.; Dee, S.

2016-12-01

Extreme flooding of the Mississippi River is costly in both economic and social terms. Despite ambitious engineering projects conceived in the early 20th century to mitigate damage from extreme floods, economic losses due to flooding have increased over recent years. Forecasting extreme flood occurrence over seasonal or longer time-scales remains a major challenge - especially in light of shifts in hydroclimatic conditions expected in response to continued greenhouse forcing. Here, we present findings from a series of paleoflood records that span the late Holocene derived from laminated sediments deposited in abandoned channels of the Mississippi River. These sedimentary archives record individual overbank floods as unique events beds with upward fining that we identify using grain-size analysis, bulk geochemistry, and radiography. We use sedimentological characteristics to reconstruct flood magnitude by calibrating our records against instrumental streamflow data from nearby gauging stations. We also use the Last Millennium Experiments of the Community Earth System Model (CESM-LME) and historical reanalysis data to examine the state of climate system around river discharge extremes. Our paleo-flood records exhibit strong non-stationarities in flood frequency and magnitude that are associated with fluctuations in the frequency of the El Niño-Southern Oscillation (ENSO), because the warm ENSO phase is associated with increased surface water storage of the lower Mississippi basin that leads to enhanced runoff delivery to the main channel. We also show that the early 20th century was a period of anomalously high flood frequency and magnitude due to the combined effects of river engineering and natural climate variability. Our findings imply that flood risk along the lower Mississippi River is tightly coupled to the frequency of ENSO, highlighting the need for robust projections of ENSO variability under greenhouse warming.

Techniques for estimating flood-peak discharges from urban basins in Missouri

USGS Publications Warehouse

Becker, L.D.

1986-01-01

Techniques are defined for estimating the magnitude and frequency of future flood peak discharges of rainfall-induced runoff from small urban basins in Missouri. These techniques were developed from an initial analysis of flood records of 96 gaged sites in Missouri and adjacent states. Final regression equations are based on a balanced, representative sampling of 37 gaged sites in Missouri. This sample included 9 statewide urban study sites, 18 urban sites in St. Louis County, and 10 predominantly rural sites statewide. Short-term records were extended on the basis of long-term climatic records and use of a rainfall-runoff model. Linear least-squares regression analyses were used with log-transformed variables to relate flood magnitudes of selected recurrence intervals (dependent variables) to selected drainage basin indexes (independent variables). For gaged urban study sites within the State, the flood peak estimates are from the frequency curves defined from the synthesized long-term discharge records. Flood frequency estimates are made for ungaged sites by using regression equations that require determination of the drainage basin size and either the percentage of impervious area or a basin development factor. Alternative sets of equations are given for the 2-, 5-, 10-, 25-, 50-, and 100-yr recurrence interval floods. The average standard errors of estimate range from about 33% for the 2-yr flood to 26% for the 100-yr flood. The techniques for estimation are applicable to flood flows that are not significantly affected by storage caused by manmade activities. Flood peak discharge estimating equations are considered applicable for sites on basins draining approximately 0.25 to 40 sq mi. (Author 's abstract)

Floods of 1950 in the Red River of the North and Winnipeg River basins

USGS Publications Warehouse

,

1952-01-01

The floods of April-July 1950 in the Red River of the North and Winnipeg River Basins were the largest that have occurred in several decades and caused the greatest damage that the flooded area has ever sustained. Five lives were lost in the United States, owing to causes directly connected with the floods. The dual peaks--on upper river and tributaries, one in April and the other in May--of nearly the same size and" the large lake-like body of flood-water ponded between Grand Forks and Winnipeg were notable features of the flood in the Red River of the North Basin. The flood in the Winnipeg River Basin was characterized by the unusually large volume of runoff and the lateness of cresting on the Lake of the Woods.The floods were caused by a combination of causes: high antecedent soil moisture, high antecedent runoff, heavy snowfall, delayed breakup, and heavy precipitation during breakup. Mid-March snow-surveys, made in the area by hydrographers of the United States and Canadian services, showed that the snow pack north of Fargo, N. Dak., had an unusually high water content and a runoff potential increasing from west to east. A narrow band, extending from near Grand Forks, N. Dak., east-northeastward across the basin, had a water content of 5 inches or higher. April 15 marked the beginning of rapid melting throughout the basins; most of the snow was turned into water by the end of the first melt period on April 24. A return of winter-like conditions until May 10 brought more snow and set the stage for second flood crests.The records of stage and discharge collected on the Red River of the North at Grand Forks, N. Dak., since 1882 show that the important 1897 flood slightly exceeded the 1950 flood in both stage and discharge. Records collected by the Geological Survey and Corps of Engineers on the Red River of the North show that the 1950 flood stages exceeded any previously known from just below the mouth of Turtle River to the international boundary. Records for streams tributary to the Red River of the North between Fargo and the Roseau River show, in general, that the 1950 flood events exceeded those of any known past floods. In the storage basins of the Winnipeg River, Lake of the Woods and Rainy Lake reached a stage comparable to that of 1916; and the Winnipeg River discharge at Slave Falls exceeded the highest previously recorded, maximum, which occurred in 1927. Records of floods on the Red River at Winnipeg show that the 1950 flood did not reach as high a stage as those of 1826, 1852, and 1861. The total tabulated damage to Winnipeg, the largest urban center in the area reported on, was about $20,000,000 in the city, and $12,000,000 in surrounding suburbs. The fight against flooding in Greater Winnipeg began on April 21 in the area adjacent to the municipal hospitals and was considered ended with the reopening of Norwood Bridge on June 1. About 80, 000 people were evacuated from their homes in Greater Winnipeg during the flood, and plans were ready to evacuate a greater number had the water risen higher.This report contains records of stage and discharge for the flood period at 70 stream-gaging stations, 21 records of mean daily discharge at stream-gaging stations, 11 records of stage at river-height gages, and 7 records of storage or elevation of reservoirs or lakes. A summary table shows crest stages and discharges at 129 points for the 1950 event compared with the highest known past stages and discharges. Also included is a discussion of concurrent meteorology and of past floods on main streams and tributaries.

Longitudinal distribution and parameters of large wood in a Mediterranean ephemeral stream

NASA Astrophysics Data System (ADS)

Galia, T.; Škarpich, V.; Tichavský, R.; Vardakas, L.; Šilhán, K.

2018-06-01

Although large wood (LW) has been intensively studied in forested basins of humid temperate climates, data on LW patterns in different fluvial environments are rather scarce. Therefore, we investigated the dimensions, characteristics, longitudinal distribution, and dynamics of LW along a 4.05-km-long reach of an ephemeral channel typical of European Mediterranean mountainous landscape (Sfakiano Gorge, Crete, Greece). We analysed a total of 795 LW pieces, and the mean observed abundance of LW was generally lower (14.3 m3/ha of active valley floor or 19.6 LW pieces/100 m of stream length) than is usually documented for more humid environments. The number of LW pieces was primarily controlled by trees growing on the valley floor. These living trees acted as important LW supply agents (by tree throws or the supply of individual branches with sufficient LW dimensions) and flow obstructions during large flood events, causing storage of transported LW pieces in jams. However, the downstream transport of LW is probably episodic, and large jams are likely formed only during major floods; after >15 years, we still observed significant imprints of the last major flood event on the present distribution of LW. The geomorphic function of LW in the studied stream can only be perceived to be a spatially limited stabilising element for sediments, which was documented by a few accumulations of coarse clastic material by LW steps and jams.

Applications of ASFCM(Assessment System of Flood Control Measurement) in Typhoon Committee Members

NASA Astrophysics Data System (ADS)

Kim, C.

2013-12-01

Due to extreme weather environment such as global warming and greenhouse effect, the risks of having flood damage has been increased with larger scale of flood damages. Therefore, it became necessary to consider modifying climate change, flood damage and its scale to the previous dimension measurement evaluation system. In this regard, it is needed to establish a comprehensive and integrated system to evaluate the most optimized measures for flood control through eliminating uncertainties of socio-economic impacts. Assessment System of Structural Flood Control Measures (ASFCM) was developed for determining investment priorities of the flood control measures and establishing the social infrastructure projects. ASFCM consists of three modules: 1) the initial setup and inputs module, 2) the flood and damage estimation module, and 3) the socio-economic analysis module. First, we have to construct the D/B for flood damage estimation, which is the initial and input data about the estimation unit, property, historical flood damages, and applied area's topographic & hydrological data. After that, it is important to classify local characteristic for constructing flood damage data. Five local characteristics (big city, medium size city, small city, farming area, and mountain area) are classified by criterion of application (population density). Next step is the floodplain simulation with HEC-RAS which is selected to simulate inundation. Through inputting the D/B and damage estimation, it is able to estimate the total damage (only direct damage) that is the amount of cost to recover the socio-economic activities back to the safe level before flood did occur. The last module suggests the economic analysis index (B/C ratio) with Multidimensional Flood Damage Analysis. Consequently, ASFCM suggests the reference index in constructing flood control measures and planning non-structural systems to reduce water-related damage. It is possible to encourage flood control planners and managers to consider and apply the socio-economic analysis results. ASFCM was applied in Republic of Korea, Thailand and Philippines to review efficiency and applicability. Figure 1. ASFCM Application(An-yang Stream, Republic of Korea)

33 CFR 203.15 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... of Congress. Flood control project: A project designed and constructed to have appreciable and... Washington, D.C. Hurricane/Shore Protection Project (HSPP). A flood control project designed and constructed... project, only those components that are necessary for the flood control function are considered eligible...

33 CFR 203.15 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... of Congress. Flood control project: A project designed and constructed to have appreciable and... Washington, D.C. Hurricane/Shore Protection Project (HSPP). A flood control project designed and constructed... project, only those components that are necessary for the flood control function are considered eligible...

33 CFR 203.15 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... of Congress. Flood control project: A project designed and constructed to have appreciable and... Washington, D.C. Hurricane/Shore Protection Project (HSPP). A flood control project designed and constructed... project, only those components that are necessary for the flood control function are considered eligible...

33 CFR 203.15 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... of Congress. Flood control project: A project designed and constructed to have appreciable and... Washington, D.C. Hurricane/Shore Protection Project (HSPP). A flood control project designed and constructed... project, only those components that are necessary for the flood control function are considered eligible...

Flood quantiles scaling with upper soil hydraulic properties for different land uses at catchment scale

NASA Astrophysics Data System (ADS)

Peña, Luis E.; Barrios, Miguel; Francés, Félix

2016-10-01

Changes in land use within a catchment are among the causes of non-stationarity in the flood regime, as they modify the upper soil physical structure and its runoff production capacity. This paper analyzes the relation between the variation of the upper soil hydraulic properties due to changes in land use and its effect on the magnitude of peak flows: (1) incorporating fractal scaling properties to relate the effect of the static storage capacity (the sum of capillary water storage capacity in the root zone, canopy interception and surface puddles) and the upper soil vertical saturated hydraulic conductivity on the flood regime; (2) describing the effect of the spatial organization of the upper soil hydraulic properties at catchment scale; (3) examining the scale properties in the parameters of the Generalized Extreme Value (GEV) probability distribution function, in relation to the upper soil hydraulic properties. This study considered the historical changes of land use in the Combeima River catchment in South America, between 1991 and 2007, using distributed hydrological modeling of daily discharges to describe the hydrological response. Through simulation of land cover scenarios, it was demonstrated that it is possible to quantify the magnitude of peak flows in scenarios of land cover changes through its Wide-Sense Simple Scaling with the upper soil hydraulic properties.

Distillation Column Flooding Predictor

DOE Office of Scientific and Technical Information (OSTI.GOV)

George E. Dzyacky

2010-11-23

The Flooding Predictor™ is a patented advanced control technology proven in research at the Separations Research Program, University of Texas at Austin, to increase distillation column throughput by over 6%, while also increasing energy efficiency by 10%. The research was conducted under a U. S. Department of Energy Cooperative Agreement awarded to George Dzyacky of 2ndpoint, LLC. The Flooding Predictor™ works by detecting the incipient flood point and controlling the column closer to its actual hydraulic limit than historical practices have allowed. Further, the technology uses existing column instrumentation, meaning no additional refining infrastructure is required. Refiners often push distillationmore » columns to maximize throughput, improve separation, or simply to achieve day-to-day optimization. Attempting to achieve such operating objectives is a tricky undertaking that can result in flooding. Operators and advanced control strategies alike rely on the conventional use of delta-pressure instrumentation to approximate the column’s approach to flood. But column delta-pressure is more an inference of the column’s approach to flood than it is an actual measurement of it. As a consequence, delta pressure limits are established conservatively in order to operate in a regime where the column is never expected to flood. As a result, there is much “left on the table” when operating in such a regime, i.e. the capacity difference between controlling the column to an upper delta-pressure limit and controlling it to the actual hydraulic limit. The Flooding Predictor™, an innovative pattern recognition technology, controls columns at their actual hydraulic limit, which research shows leads to a throughput increase of over 6%. Controlling closer to the hydraulic limit also permits operation in a sweet spot of increased energy-efficiency. In this region of increased column loading, the Flooding Predictor is able to exploit the benefits of higher liquid/vapor traffic that produce increased contact area and lead to substantial increases in separation efficiency – which translates to a 10% increase in energy efficiency on a BTU/bbl basis. The Flooding Predictor™ operates on the principle that between five to sixty minutes in advance of a flooding event, certain column variables experience an oscillation, a pre-flood pattern. The pattern recognition system of the Flooding Predictor™ utilizes the mathematical first derivative of certain column variables to identify the column’s pre-flood pattern(s). This pattern is a very brief, highly repeatable, simultaneous movement among the derivative values of certain column variables. While all column variables experience negligible random noise generated from the natural frequency of the process, subtle pre-flood patterns are revealed among sub-sets of the derivative values of column variables as the column approaches its hydraulic limit. The sub-set of column variables that comprise the pre-flood pattern is identified empirically through in a two-step process. First, 2ndpoint’s proprietary off-line analysis tool is used to mine historical data for pre-flood patterns. Second, the column is flood-tested to fine-tune the pattern recognition for commissioning. Then the Flooding Predictor™ is implemented as closed-loop advanced control strategy on the plant’s distributed control system (DCS), thus automating control of the column at its hydraulic limit.« less

What are the hydro-meteorological controls on flood characteristics?

NASA Astrophysics Data System (ADS)

Nied, Manuela; Schröter, Kai; Lüdtke, Stefan; Nguyen, Viet Dung; Merz, Bruno

2017-02-01

Flood events can be expressed by a variety of characteristics such as flood magnitude and extent, event duration or incurred loss. Flood estimation and management may benefit from understanding how the different flood characteristics relate to the hydrological catchment conditions preceding the event and to the meteorological conditions throughout the event. In this study, we therefore propose a methodology to investigate the hydro-meteorological controls on different flood characteristics, based on the simulation of the complete flood risk chain from the flood triggering precipitation event, through runoff generation in the catchment, flood routing and possible inundation in the river system and floodplains to flood loss. Conditional cumulative distribution functions and regression tree analysis delineate the seasonal varying flood processes and indicate that the effect of the hydrological pre-conditions, i.e. soil moisture patterns, and of the meteorological conditions, i.e. weather patterns, depends on the considered flood characteristic. The methodology is exemplified for the Elbe catchment. In this catchment, the length of the build-up period, the event duration and the number of gauges undergoing at least a 10-year flood are governed by weather patterns. The affected length and the number of gauges undergoing at least a 2-year flood are however governed by soil moisture patterns. In case of flood severity and loss, the controlling factor is less pronounced. Severity is slightly governed by soil moisture patterns whereas loss is slightly governed by weather patterns. The study highlights that flood magnitude and extent arise from different flood generation processes and concludes that soil moisture patterns as well as weather patterns are not only beneficial to inform on possible flood occurrence but also on the involved flood processes and resulting flood characteristics.

33 CFR 208.19 - Marshall Ford Dam and Reservoir (Mansfield Dam and Lake Travis), Colorado River, Tex.

Code of Federal Regulations, 2013 CFR

2013-07-01

... and Reservoir in the interest of flood control as follows: (a) Water Control Plan—(1) General..., flood control, stream regulation, generation of power, irrigation, water supply, and recreation uses. (2) Overall plan for water control. Within the Colorado River Basin, four Federal projects provide flood...

33 CFR 208.19 - Marshall Ford Dam and Reservoir (Mansfield Dam and Lake Travis), Colorado River, Tex.

Code of Federal Regulations, 2012 CFR

2012-07-01

... and Reservoir in the interest of flood control as follows: (a) Water Control Plan—(1) General..., flood control, stream regulation, generation of power, irrigation, water supply, and recreation uses. (2) Overall plan for water control. Within the Colorado River Basin, four Federal projects provide flood...

Connecting the Dots: Hydrologic Connectivity Between Wetlands and Other Wetlands and Waterbodies

EPA Science Inventory

Wetlands perform numerous ecosystem functions that in turn provide abundant ecosystem services beneficial to humankind. These may include, but are not limited to, flood water storage and release, nutrient transformations, carbon sequestration, and the provision of habitat or ref...

Impact of hydrological alterations on river-groundwater exchange and water quality in a semi-arid area: Nueces River, Texas.

PubMed

Murgulet, Dorina; Murgulet, Valeriu; Spalt, Nicholas; Douglas, Audrey; Hay, Richard G

2016-12-01

There is a lack of understanding and methods for assessing the effects of anthropogenic disruptions, (i.e. river fragmentation due to dam construction) on the extent and degree of groundwater-surface water interaction and geochemical processes affecting the quality of water in semi-arid, coastal catchments. This study applied a novel combination of electrical resistivity tomography (ERT) and elemental and isotope geochemistry in a coastal river disturbed by extended drought and periodic flooding due to the operation of multiple dams. Geochemical analyses show that the saltwater barrier causes an increase in salinity in surface water in the downstream river as a result of limited freshwater inflows, strong evaporation effects on shallow groundwater and mostly stagnant river water, and is not due to saltwater intrusion by tidal flooding. Discharge from bank storage is dominant (~84%) in the downstream fragment and its contribution could increase salinity levels within the hyporheic zone and surface water. When surface water levels go up due to upstream freshwater releases the river temporarily displaces high salinity water trapped in the hyporheic zone to the underlying aquifer. Geochemical modeling shows a higher contribution of distant and deeper groundwater (~40%) in the upstream river and lower discharge from bank storage (~13%) through the hyporheic zone. Recharge from bank storage is a source of high salt to both upstream and downstream portions of the river but its contribution is higher below the dam. Continuous ERT imaging of the river bed complements geochemistry findings and indicate that while lithologically similar, downstream of the dam, the shallow aquifer is affected by salinization while fresher water saturates the aquifer in the upstream fragment. The relative contribution of flows (i.e. surface water releases or groundwater discharge) as related to the river fragmentation control changes of streamwater chemistry and likely impact the interpretation of seasonal trends. Copyright © 2016 Elsevier B.V. All rights reserved.

Quantifying the potential for reservoirs to secure future surface water yields in the world’s largest river basins

NASA Astrophysics Data System (ADS)

Liu, Lu; Parkinson, Simon; Gidden, Matthew; Byers, Edward; Satoh, Yusuke; Riahi, Keywan; Forman, Barton

2018-04-01

Surface water reservoirs provide us with reliable water supply, hydropower generation, flood control and recreation services. Yet reservoirs also cause flow fragmentation in rivers and lead to flooding of upstream areas, thereby displacing existing land-use activities and ecosystems. Anticipated population growth and development coupled with climate change in many regions of the globe suggests a critical need to assess the potential for future reservoir capacity to help balance rising water demands with long-term water availability. Here, we assess the potential of large-scale reservoirs to provide reliable surface water yields while also considering environmental flows within 235 of the world’s largest river basins. Maps of existing cropland and habitat conservation zones are integrated with spatially-explicit population and urbanization projections from the Shared Socioeconomic Pathways to identify regions unsuitable for increasing water supply by exploiting new reservoir storage. Results show that even when maximizing the global reservoir storage to its potential limit (∼4.3–4.8 times the current capacity), firm yields would only increase by about 50% over current levels. However, there exist large disparities across different basins. The majority of river basins in North America are found to gain relatively little firm yield by increasing storage capacity, whereas basins in Southeast Asia display greater potential for expansion as well as proportional gains in firm yield under multiple uncertainties. Parts of Europe, the United States and South America show relatively low reliability of maintaining current firm yields under future climate change, whereas most of Asia and higher latitude regions display comparatively high reliability. Findings from this study highlight the importance of incorporating different factors, including human development, land-use activities, and climate change, over a time span of multiple decades and across a range of different scenarios when quantifying available surface water yields and the potential for reservoir expansion.

BIOAVAILABILITY OF MERCURY IN SEDIMENTS FROM A FLOOD CONTROL RESERVOIR TO HYALELLA AZTECA

EPA Science Inventory

In the last three years, mercury contamination in North Mississippi flood control reservoirs has become a growing concern. Previous data indicate that three flood control reservoirs have similar total mercury sediment concentrations and that fish collected from one reservoir cont...

Machine Learning for Flood Prediction in Google Earth Engine

NASA Astrophysics Data System (ADS)

Kuhn, C.; Tellman, B.; Max, S. A.; Schwarz, B.

2015-12-01

With the increasing availability of high-resolution satellite imagery, dynamic flood mapping in near real time is becoming a reachable goal for decision-makers. This talk describes a newly developed framework for predicting biophysical flood vulnerability using public data, cloud computing and machine learning. Our objective is to define an approach to flood inundation modeling using statistical learning methods deployed in a cloud-based computing platform. Traditionally, static flood extent maps grounded in physically based hydrologic models can require hours of human expertise to construct at significant financial cost. In addition, desktop modeling software and limited local server storage can impose restraints on the size and resolution of input datasets. Data-driven, cloud-based processing holds promise for predictive watershed modeling at a wide range of spatio-temporal scales. However, these benefits come with constraints. In particular, parallel computing limits a modeler's ability to simulate the flow of water across a landscape, rendering traditional routing algorithms unusable in this platform. Our project pushes these limits by testing the performance of two machine learning algorithms, Support Vector Machine (SVM) and Random Forests, at predicting flood extent. Constructed in Google Earth Engine, the model mines a suite of publicly available satellite imagery layers to use as algorithm inputs. Results are cross-validated using MODIS-based flood maps created using the Dartmouth Flood Observatory detection algorithm. Model uncertainty highlights the difficulty of deploying unbalanced training data sets based on rare extreme events.

Evolvement rules of basin flood risk under low-carbon mode. Part I: response of soil organic carbon to land use change and its influence on land use planning in the Haihe basin.

PubMed

Li, Fawen; Wang, Liping; Zhao, Yong

2017-08-01

Soil organic carbon (SOC) plays an important role in the global carbon cycle. The aim of this study was to evaluate the response of SOC to land use change and its influence on land use planning in the Haihe basin, and provide planning land use pattern for basin flood risk assessment. Firstly, the areas of different land use types in 1980, 2008, and the planning year (2020) were counted by area statistics function of ArcGIS. Then, the transfer matrixes of land use were produced by spatial overlay analysis function. Lastly, based on the land use maps, soil type map and soil profile database, SOC storage of different land use types in three different periods were calculated. The results showed the patterns of land use have changed a lot from 1980 to 2008, among the 19,835 km 2 of grassland was transformed into forestland, which was the largest conversion landscape. And land use conversion brought the SOC storage changes. Total carbon source was 88.83 Tg, and total carbon sink was 85.49 Tg. So, the Haihe basin presented as a carbon source from 1980 to 2008. From 2008 to 2020, the changes of forestland and grassland are the biggest in Haihe basin, which cause the SOC pool change from a carbon source to a carbon sink. SOC storage will increase from 2420.5 Tg in 2008 to 2495.5 Tg in 2020. The changing trend is conducive to reducing atmospheric concentrations. Therefore, land use planning in Haihe basin is reasonable and can provide the underlying surface condition for flood risk assessment.

A daily wetness index from satellite gravity for near-real time global monitoring of hydrological extremes

NASA Astrophysics Data System (ADS)

Gouweleeuw, Ben; Kvas, Andreas; Gruber, Christian; Mayer-Gürr, Torsten; Flechtner, Frank; Hasan, Mehedi; Güntner, Andreas

2017-04-01

Since April 2002, the Gravity Recovery and Climate Experiment (GRACE) satellite mission has been churning out water storage anomaly data, which has been shown to be a unique descriptor of large-scale hydrological extreme events. Nonetheless, efforts to assess the comprehensive information from GRACE on total water storage variations for near-real time flood or drought monitoring have been limited so far, primarily due to its coarse temporal (weekly to monthly) and spatial (> 150.000 km2) resolution and the latency of standard products of about 2 months,. Pending the status of the aging GRACE satellite mission, the Horizon 2020 funded EGSIEM (European Gravity Service for Improved Emergency Management) project is scheduled to launch a 6 month duration near-real time test run of GRACE gravity field data from April 2017 onward, which will provide daily gridded data with a latency of 5 days. This fast availability allows the monitoring of total water storage variations related to hydrological extreme events, as they occur, as opposed to a 'confirmation after occurrence', which is the current situation. This contribution proposes a global GRACE-derived gridded wetness indicator, expressed as a gravity anomaly in dimensionless units of standard deviation. Results of a retrospective evaluation (April 2002-December 2015) of the proposed index against databases of hydrological extremes will be presented. It is shown that signals for large extreme floods related to heavy/monsoonal rainfall are picked up really well in the Southern Hemisphere and lower Northern Hemisphere (Africa, S-America, Australia, S-Asia), while extreme floods in the Northern Hemisphere (Russia) related to snow melt are often not. The latter is possibly related to a lack of mass movement over longer distances, e.g. when melt water is not drained due to river ice blocking.

Assessing the efficiency of different CSO positions based on network graph characteristics.

PubMed

Sitzenfrei, R; Urich, C; Möderl, M; Rauch, W

2013-01-01

The technical design of urban drainage systems comprises two major aspects: first, the spatial layout of the sewer system and second, the pipe-sizing process. Usually, engineers determine the spatial layout of the sewer network manually, taking into account physical features and future planning scenarios. Before the pipe-sizing process starts, it is important to determine locations of possible weirs and combined sewer overflows (CSOs) based on, e.g. distance to receiving water bodies or to a wastewater treatment plant and available space for storage units. However, positions of CSOs are also determined by topological characteristics of the sewer networks. In order to better understand the impact of placement choices for CSOs and storage units in new systems, this work aims to determine case unspecific, general rules. Therefore, based on numerous, stochastically generated virtual alpine sewer systems of different sizes it is investigated how choices for placement of CSOs and storage units have an impact on the pipe-sizing process (hence, also on investment costs) and on technical performance (CSO efficiency and flooding). To describe the impact of the topological positions of these elements in the sewer networks, graph characteristics are used. With an evaluation of 2,000 different alpine combined sewer systems, it was found that, as expected, with CSOs at more downstream positions in the network, greater construction costs and better performance regarding CSO efficiency result. At a specific point (i.e. topological network position), no significant difference (further increase) in construction costs can be identified. Contrarily, the flooding efficiency increases with more upstream positions of the CSOs. Therefore, CSO and flooding efficiency are in a trade-off conflict and a compromise is required.

Enhancing drought resilience with conjunctive use and managed aquifer recharge in California and Arizona

USGS Publications Warehouse

Scanlon, Bridget R.; Reedy, Robert C.; Faunt, Claudia; Pool, Donald R.; Uhlman, Kristine;

2016-01-01

Projected longer‐term droughts and intense floods underscore the need to store more water to manage climate extremes. Here we show how depleted aquifers have been used to store water by substituting surface water use for groundwater pumpage (conjunctive use, CU) or recharging groundwater with surface water (Managed Aquifer Recharge, MAR). Unique multi‐decadal monitoring from thousands of wells and regional modeling datasets for the California Central Valley and central Arizona were used to assess CU and MAR. In addition to natural reservoir capacity related to deep water tables, historical groundwater depletion further expanded aquifer storage by ~44 km3 in the Central Valley and by ~100 km3 in Arizona, similar to or exceeding current surface reservoir capacity by up to three times. Local river water and imported surface water, transported through 100s of km of canals, is substituted for groundwater (≤15 km3/yr, CU) or is used to recharge groundwater (MAR, ≤1.5 km3/yr) during wet years shifting to mostly groundwater pumpage during droughts. In the Central Valley, CU and MAR locally reversed historically declining water‐level trends, which contrasts with simulated net regional groundwater depletion. In Arizona, CU and MAR also reversed historically declining groundwater level trends in Active Management Areas. These rising trends contrast with current declining trends in irrigated areas that lack access to surface water to support CU or MAR. Use of depleted aquifers as reservoirs could expand with winter flood irrigation or capturing flood discharges to the Pacific (0 – 1.6 km3/yr, 2000–2014) with additional infrastructure in California. Because flexibility and expanded portfolio options translate to resilience, CU and MAR enhance drought resilience through multi‐year storage, complementing shorter term surface reservoir storage, and facilitating water markets.

33 CFR 203.48 - Inspection guidelines for non-Federal flood control works.

Code of Federal Regulations, 2011 CFR

2011-07-01

..., DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE EMERGENCY EMPLOYMENT OF ARMY AND OTHER RESOURCES, NATURAL DISASTER PROCEDURES Rehabilitation Assistance for Flood Control Works Damaged by Flood or Coastal Storm...

33 CFR 203.48 - Inspection guidelines for non-Federal flood control works.

Code of Federal Regulations, 2014 CFR

2014-07-01

..., DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE EMERGENCY EMPLOYMENT OF ARMY AND OTHER RESOURCES, NATURAL DISASTER PROCEDURES Rehabilitation Assistance for Flood Control Works Damaged by Flood or Coastal Storm...

33 CFR 203.44 - Rehabilitation of non-Federal flood control works.

Code of Federal Regulations, 2014 CFR

2014-07-01

..., DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE EMERGENCY EMPLOYMENT OF ARMY AND OTHER RESOURCES, NATURAL DISASTER PROCEDURES Rehabilitation Assistance for Flood Control Works Damaged by Flood or Coastal Storm...

33 CFR 203.44 - Rehabilitation of non-Federal flood control works.

Code of Federal Regulations, 2012 CFR

2012-07-01

..., DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE EMERGENCY EMPLOYMENT OF ARMY AND OTHER RESOURCES, NATURAL DISASTER PROCEDURES Rehabilitation Assistance for Flood Control Works Damaged by Flood or Coastal Storm...

33 CFR 203.44 - Rehabilitation of non-Federal flood control works.

Code of Federal Regulations, 2011 CFR

2011-07-01

..., DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE EMERGENCY EMPLOYMENT OF ARMY AND OTHER RESOURCES, NATURAL DISASTER PROCEDURES Rehabilitation Assistance for Flood Control Works Damaged by Flood or Coastal Storm...

33 CFR 203.44 - Rehabilitation of non-Federal flood control works.

Code of Federal Regulations, 2013 CFR

2013-07-01

..., DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE EMERGENCY EMPLOYMENT OF ARMY AND OTHER RESOURCES, NATURAL DISASTER PROCEDURES Rehabilitation Assistance for Flood Control Works Damaged by Flood or Coastal Storm...

33 CFR 203.44 - Rehabilitation of non-Federal flood control works.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE EMERGENCY EMPLOYMENT OF ARMY AND OTHER RESOURCES, NATURAL DISASTER PROCEDURES Rehabilitation Assistance for Flood Control Works Damaged by Flood or Coastal Storm...

33 CFR 203.48 - Inspection guidelines for non-Federal flood control works.

Code of Federal Regulations, 2012 CFR

2012-07-01

..., DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE EMERGENCY EMPLOYMENT OF ARMY AND OTHER RESOURCES, NATURAL DISASTER PROCEDURES Rehabilitation Assistance for Flood Control Works Damaged by Flood or Coastal Storm...

33 CFR 203.48 - Inspection guidelines for non-Federal flood control works.

Code of Federal Regulations, 2013 CFR

2013-07-01

..., DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE EMERGENCY EMPLOYMENT OF ARMY AND OTHER RESOURCES, NATURAL DISASTER PROCEDURES Rehabilitation Assistance for Flood Control Works Damaged by Flood or Coastal Storm...

Early physiological flood tolerance is followed by slow post-flooding root recovery in the dryland riparian tree Eucalyptus camaldulensis subsp. refulgens.

PubMed

Argus, R E; Colmer, T D; Grierson, P F

2015-06-01

We investigated physiological and morphological responses to flooding and recovery in Eucalyptus camaldulensis subsp. refulgens, a riparian tree species from a dryland region prone to intense episodic floods. Seedlings in soil flooded for 88 d produced extensive adventitious roots, displayed stem hypertrophy (stem diameter increased by 93%) and increased root porosity owing to aerenchyma formation. Net photosynthesis (Pn) and stomatal conductance (gs) were maintained for at least 2 weeks of soil flooding, contrasting with previous studies of other subspecies of E. camaldulensis. Gradual declines followed in both gs (30% less than controls) and Pn (19% less). Total leaf soluble sugars did not differ between flooded and control plants. Root mass did not recover 32 d after flooding ceased, but gs was not lower than controls, suggesting the root system was able to functionally compensate. However, the limited root growth during recovery after flooding was surprising given the importance of extensive root systems in dryland environments. We conclude that early flood tolerance could be an adaptation to capitalize on scarce water resources in a water-limited environment. Overall, our findings highlight the need to assess flooding responses in relation to a species' fitness for particular flood regimes or ecological niches. © 2014 John Wiley & Sons Ltd.

Nested 1D-2D approach for urban surface flood modeling

NASA Astrophysics Data System (ADS)

Murla, Damian; Willems, Patrick

2015-04-01

Floods in urban areas as a consequence of sewer capacity exceedance receive increased attention because of trends in urbanization (increased population density and impermeability of the surface) and climate change. Despite the strong recent developments in numerical modeling of water systems, urban surface flood modeling is still a major challenge. Whereas very advanced and accurate flood modeling systems are in place and operation by many river authorities in support of flood management along rivers, this is not yet the case in urban water management. Reasons include the small scale of the urban inundation processes, the need to have very high resolution topographical information available, and the huge computational demands. Urban drainage related inundation modeling requires a 1D full hydrodynamic model of the sewer network to be coupled with a 2D surface flood model. To reduce the computational times, 0D (flood cones), 1D/quasi-2D surface flood modeling approaches have been developed and applied in some case studies. In this research, a nested 1D/2D hydraulic model has been developed for an urban catchment at the city of Gent (Belgium), linking the underground sewer (minor system) with the overland surface (major system). For the overland surface flood modelling, comparison was made of 0D, 1D/quasi-2D and full 2D approaches. The approaches are advanced by considering nested 1D-2D approaches, including infiltration in the green city areas, and allowing the effects of surface storm water storage to be simulated. An optimal nested combination of three different mesh resolutions was identified; based on a compromise between precision and simulation time for further real-time flood forecasting, warning and control applications. Main streets as mesh zones together with buildings as void regions constitute one of these mesh resolution (3.75m2 - 15m2); they have been included since they channel most of the flood water from the manholes and they improve the accuracy of interactions within the 1D sewer network. Other areas that recorded flooding outside the main streets have been also included with the second mesh resolution for an accurate determination of flood maps (12.5m2 - 50m2). Permeable areas have been identified and used as infiltration zones using the Horton infiltration model. A mesh sensitivity analysis has been performed for the low flood risk areas for a proper model optimization. As outcome of that analysis, the third mesh resolution has been chosen (75m2 - 300m2). Performance tests have been applied for several synthetic design storms as well as historical storm events displaying satisfactory results upon comparing the flood mapping outcomes produced by the different approaches. Accounting for the infiltration in the green city spaces reduces the flood extents in the range 39% - 68%, while the average reduction in flood volume equals 86%. Acknowledgement: Funding for this research was provided by the Interreg IVB NWE programme (project RainGain) and the Belgian Science Policy Office (project PLURISK). The high resolution topographical information data were obtained from the geographical information service AGIV; the original full hydrodynamic sewer network model from the service company Farys, and the InfoWorks licence from Innovyze.

Floods of October 1977 in southern Arizona and March 1978 in central Arizona

USGS Publications Warehouse

Aldridge, Byron Neil; Eychaner, James H.

1984-01-01

Major floods occurred in October 1977 and March 1978 in Arizona. As much as 14 inches of rain fell during October 6-9, 1977, over the mountains of southern Arizona and northern Mexico resulting in the highest discharge since at least 1892 on the Santa Cruz River upstream from Tucson. The flood inundated areas as much as 4 miles wide, covered at least 16,000 acres of farmland, and caused $15.2 million in damage. Residential losses occurred at Nogales, Amado, Green Valley, and Sahuarita. Severe erosional damage occurred along the Santa Cruz River, Agua Fria Canyon, Potrero Creek, and many small drainages in the Sonoita Creek basin. The peak discharge in Agua Fria Canyon was the highest since before 1900. Less severe flooding occurred along the San Pedro River and the Gila River downstream from the San Pedro. Widespread rainfall of 3 to 6 inches and 9 to 14 inches in some areas in the central mountains during February 27 to March 3, 1978, caused the highest discharge since 1920 on the Salt River in Phoenix and resulted in three deaths. Flooding along the Salt and Gila Rivers and several lesser streams caused statewide damage totaling $65.9 million, of which about $37 million occurred in Maricopa County. Nine counties were declared disaster areas. During the flood of March 1978, moderate peak discharges and unusually high volumes of runoff occurred on tributaries to the Salt and Verde Rivers upstream from a system of reservoirs. Flood magnitudes were greater at the main-stem gaging stations than on the tributaries. The peak discharge into Theodore Roosevelt Lake, which was 21 percent full at the start of the flood, was about 155,000 cubic feet per second, the largest known from 1890 to 1978. The reservoirs stored large quantities of water and greatly reduced the magnitude of the flood. The peak discharge of the Salt River was 125,000 cubic feet per second below Granite Reef Dam and 122,000 cubic feet per second at Phoenix. Discharges in excess of 100,000 cubic feet per second occurred for 8 hours. Without the storage provided by the reservoirs, the peak discharge on the Salt River would have been 260,000 cubic feet per second, and the discharge would have exceeded 100,000 cubic feet per second for 66 hours. The Verde River was the principal flood source, but flows at the upstream gaging stations did not indicate the magnitude of the impending flood at Horseshoe Reservoir because large inflow from tributaries immediately upstream from the reservoir caused the river to rise at downstream stations before it rose at upstream stations. About 17 percent of the water entering the reach from Granite Reef Dam to Gillespie Dam went to recharge, temporary ground-water storage, or evapotranspiration losses. All water was stored at Painted Rock Reservoir and released at a low rate that prevented water from reaching the Gila River near Mohawk gaging station.

Economic impacts of urban flooding in South Florida: Potential consequences of managing groundwater to prevent salt water intrusion.

PubMed

Czajkowski, Jeffrey; Engel, Vic; Martinez, Chris; Mirchi, Ali; Watkins, David; Sukop, Michael C; Hughes, Joseph D

2018-04-15

High-value urban zones in coastal South Florida are considered particularly vulnerable to salt water intrusion into the groundwater-based, public water supplies caused by sea level rise (SLR) in combination with the low topography, existing high water table, and permeable karst substrate. Managers in the region closely regulate water depths in the extensive South Florida canal network to control closely coupled groundwater levels and thereby reduce the risk of saltwater intrusion into the karst aquifer. Potential SLR adaptation strategies developed by local managers suggest canal and groundwater levels may have to be increased over time to prevent the increased salt water intrusion risk to groundwater resources. However, higher canal and groundwater levels cause the loss of unsaturated zone storage and lead to an increased risk of inland flooding when the recharge from rainfall exceeds the capacity of the unsaturated zone to absorb it and the water table reaches the surface. Consequently, higher canal and groundwater levels are also associated with increased risk of economic losses, especially during the annual wet seasons. To help water managers and urban planners in this region better understand this trade-off, this study models the relationships between flood insurance claims and groundwater levels in Miami-Dade County. Via regression analyses, we relate the incurred number of monthly flood claims in 16 Miami-Dade County watersheds to monthly groundwater levels over the period from 1996 to 2010. We utilize these estimated statistical relationships to further illustrate various monthly flood loss scenarios that could plausibly result, thereby providing an economic quantification of a "too much water" trade-off. Importantly, this understanding is the first of its kind in South Florida and is exceedingly useful for regional-scale hydro-economic optimization models analyzing trade-offs associated with high water levels. Copyright © 2017 Elsevier B.V. All rights reserved.

Integrating a reservoir regulation scheme into a spatially distributed hydrological model

DOE PAGES

Zhao, Gang; Gao, Huili; Naz, Bibi S; ...

2016-10-14

During the past several decades, numerous reservoirs have been built across the world for a variety of purposes such as flood control, irrigation, municipal/industrial water supplies, and hydropower generation. Consequently, timing and magnitude of natural streamflows have been altered significantly by reservoir operations. In addition, the hydrological cycle can be modified by land-use/land-cover and climate changes. To understand the fine-scale feedback between hydrological processes and water management decisions, a distributed hydrological model embedded with a reservoir component is desired. In this study, a multi-purpose reservoir module with predefined complex operational rules was integrated into the Distributed Hydrology Soil Vegetation Modelmore » (DHSVM). Conditional operating rules, which are designed to reduce flood risk and enhance water supply reliability, were adopted in this module. The performance of the integrated model was tested over the upper Brazos River Basin in Texas, where two U.S. Army Corps of Engineers reservoirs, Lake Whitney and Aquilla Lake, are located. The integrated DHSVM was calibrated and validated using observed reservoir inflow, outflow, and storage data. The error statistics were summarized for both reservoirs on a daily, weekly, and monthly basis. Using the weekly reservoir storage for Lake Whitney as an example, the coefficient of determination (R 2) and the Nash-Sutcliff Efficiency (NSE) were 0.85 and 0.75, respectively. These results suggest that this reservoir module holds promise for use in sub-monthly hydrological simulations. Furthermore, with the new reservoir component, the DHSVM provides a platform to support adaptive water resources management under the impacts of evolving anthropogenic activities and substantial environmental changes.« less

Integrating a reservoir regulation scheme into a spatially distributed hydrological model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, Gang; Gao, Huili; Naz, Bibi S

During the past several decades, numerous reservoirs have been built across the world for a variety of purposes such as flood control, irrigation, municipal/industrial water supplies, and hydropower generation. Consequently, timing and magnitude of natural streamflows have been altered significantly by reservoir operations. In addition, the hydrological cycle can be modified by land-use/land-cover and climate changes. To understand the fine-scale feedback between hydrological processes and water management decisions, a distributed hydrological model embedded with a reservoir component is desired. In this study, a multi-purpose reservoir module with predefined complex operational rules was integrated into the Distributed Hydrology Soil Vegetation Modelmore » (DHSVM). Conditional operating rules, which are designed to reduce flood risk and enhance water supply reliability, were adopted in this module. The performance of the integrated model was tested over the upper Brazos River Basin in Texas, where two U.S. Army Corps of Engineers reservoirs, Lake Whitney and Aquilla Lake, are located. The integrated DHSVM was calibrated and validated using observed reservoir inflow, outflow, and storage data. The error statistics were summarized for both reservoirs on a daily, weekly, and monthly basis. Using the weekly reservoir storage for Lake Whitney as an example, the coefficient of determination (R 2) and the Nash-Sutcliff Efficiency (NSE) were 0.85 and 0.75, respectively. These results suggest that this reservoir module holds promise for use in sub-monthly hydrological simulations. Furthermore, with the new reservoir component, the DHSVM provides a platform to support adaptive water resources management under the impacts of evolving anthropogenic activities and substantial environmental changes.« less

Flood risk assessment of land pollution hotspots

NASA Astrophysics Data System (ADS)

Masi, Matteo; Arrighi, Chiara; Iannelli, Renato

2017-04-01

Among the risks caused by extreme events, the potential spread of pollutants stored in land hotspots due to floods is an aspect that has been rarely examined with a risk-based approach. In this contribution, an attempt to estimate pollution risks related to flood events of land pollution hotspots was carried out. Flood risk has been defined as the combination of river flood hazard, hotspots exposure and vulnerability to contamination of the area, i.e. the expected severity of the environmental impacts. The assessment was performed on a geographical basis, using geo-referenced open data, available from databases of land management institutions, authorities and agencies. The list of land pollution hotspots included landfills and other waste handling facilities (e.g., temporary storage, treatment and recycling sites), municipal wastewater treatment plants, liquid waste treatment facilities and contaminated sites. The assessment was carried out by combining geo-referenced data of pollution hotspots with flood hazard maps. We derived maps of land pollution risk based on geographical and geological properties and source characteristics available from environmental authorities. These included information about soil particle size, soil hydraulic conductivity, terrain slope, type of stored pollutants, the type of facility, capacity, size of the area, land use, etc. The analysis was carried out at catchment scale. The case study of the Arno river basin in Tuscany (central Italy) is presented.

33 CFR 240.6 - General policy.

Code of Federal Regulations, 2012 CFR

2012-07-01

... they generally make reference to flood control “projects,” should be understood to have equivalent... subsequent maintenance of the creditable non-Federal flood control work will not be credited. In the event... GENERAL CREDIT FOR FLOOD CONTROL § 240.6 General policy. (a) Section 104 is applicable only to projects...

33 CFR 240.6 - General policy.

Code of Federal Regulations, 2010 CFR

2010-07-01

... they generally make reference to flood control “projects,” should be understood to have equivalent... subsequent maintenance of the creditable non-Federal flood control work will not be credited. In the event... GENERAL CREDIT FOR FLOOD CONTROL § 240.6 General policy. (a) Section 104 is applicable only to projects...

33 CFR 240.6 - General policy.

Code of Federal Regulations, 2013 CFR

2013-07-01

... they generally make reference to flood control “projects,” should be understood to have equivalent... subsequent maintenance of the creditable non-Federal flood control work will not be credited. In the event... GENERAL CREDIT FOR FLOOD CONTROL § 240.6 General policy. (a) Section 104 is applicable only to projects...

33 CFR 240.6 - General policy.

Code of Federal Regulations, 2011 CFR

2011-07-01

... they generally make reference to flood control “projects,” should be understood to have equivalent... subsequent maintenance of the creditable non-Federal flood control work will not be credited. In the event... GENERAL CREDIT FOR FLOOD CONTROL § 240.6 General policy. (a) Section 104 is applicable only to projects...

33 CFR 240.6 - General policy.

Code of Federal Regulations, 2014 CFR

2014-07-01

... they generally make reference to flood control “projects,” should be understood to have equivalent... subsequent maintenance of the creditable non-Federal flood control work will not be credited. In the event... GENERAL CREDIT FOR FLOOD CONTROL § 240.6 General policy. (a) Section 104 is applicable only to projects...

Evaluating the application of multi-satellite observation in hydrologic modeling

USDA-ARS?s Scientific Manuscript database

When monitoring local or regional hydrosphere dynamics for applications such as agricultural productivity or drought and flooding events, it is necessary to have accurate, high-resolution estimates of terrestrial water and energy storages. Though in-situ observations provide reliable estimates of hy...

33 CFR 320.4 - General policies for evaluating permit applications.

Code of Federal Regulations, 2014 CFR

2014-07-01

... recharge areas; (vii) Wetlands which serve significant water purification functions; and (viii) Wetlands..., water supply and conservation, water quality, energy needs, safety, food and fiber production, mineral... valuable storage areas for storm and flood waters; (vi) Wetlands which are ground water discharge areas...

CCD imaging sensors

NASA Technical Reports Server (NTRS)

Janesick, James R. (Inventor); Elliott, Stythe T. (Inventor)

1989-01-01

A method for promoting quantum efficiency (QE) of a CCD imaging sensor for UV, far UV and low energy x-ray wavelengths by overthinning the back side beyond the interface between the substrate and the photosensitive semiconductor material, and flooding the back side with UV prior to using the sensor for imaging. This UV flooding promotes an accumulation layer of positive states in the oxide film over the thinned sensor to greatly increase QE for either frontside or backside illumination. A permanent or semipermanent image (analog information) may be stored in a frontside SiO.sub.2 layer over the photosensitive semiconductor material using implanted ions for a permanent storage and intense photon radiation for a semipermanent storage. To read out this stored information, the gate potential of the CCD is biased more negative than that used for normal imaging, and excess charge current thus produced through the oxide is integrated in the pixel wells for subsequent readout by charge transfer from well to well in the usual manner.

Bathymetric map, area/capacity table, and sediment volume estimate for Millwood Lake near Ashdown, Arkansas, 2013

USGS Publications Warehouse

Richards, Joseph M.; Green, W. Reed

2013-01-01

Millwood Lake, in southwestern Arkansas, was constructed and is operated by the U.S. Army Corps of Engineers (USACE) for flood-risk reduction, water supply, and recreation. The lake was completed in 1966 and it is likely that with time sedimentation has resulted in the reduction of storage capacity of the lake. The loss of storage capacity can cause less water to be available for water supply, and lessens the ability of the lake to mitigate flooding. Excessive sediment accumulation also can cause a reduction in aquatic habitat in some areas of the lake. Although many lakes operated by the USACE have periodic bathymetric and sediment surveys, none have been completed for Millwood Lake. In March 2013, the U.S. Geological Survey (USGS), in cooperation with the USACE, surveyed the bathymetry of Millwood Lake to prepare an updated bathymetric map and area/capacity table. The USGS also collected sediment thickness data in June 2013 to estimate the volume of sediment accumulated in the lake.

Water Management Applications of Advanced Precipitation Products

NASA Astrophysics Data System (ADS)

Johnson, L. E.; Braswell, G.; Delaney, C.

2012-12-01

Advanced precipitation sensors and numerical models track storms as they occur and forecast the likelihood of heavy rain for time frames ranging from 1 to 8 hours, 1 day, and extended outlooks out to 3 to 7 days. Forecast skill decreases at the extended time frames but the outlooks have been shown to provide "situational awareness" which aids in preparation for flood mitigation and water supply operations. In California the California-Nevada River Forecast Centers and local Weather Forecast Offices provide precipitation products that are widely used to support water management and flood response activities of various kinds. The Hydrometeorology Testbed (HMT) program is being conducted to help advance the science of precipitation tracking and forecasting in support of the NWS. HMT high-resolution products have found applications for other non-federal water management activities as well. This presentation will describe water management applications of HMT advanced precipitation products, and characterization of benefits expected to accrue. Two case examples will be highlighted, 1) reservoir operations for flood control and water supply, and 2) urban stormwater management. Application of advanced precipitation products in support of reservoir operations is a focus of the Sonoma County Water Agency. Examples include: a) interfacing the high-resolution QPE products with a distributed hydrologic model for the Russian-Napa watersheds, b) providing early warning of in-coming storms for flood preparedness and water supply storage operations. For the stormwater case, San Francisco wastewater engineers are developing a plan to deploy high resolution gap-filling radars looking off shore to obtain longer lead times on approaching storms. A 4 to 8 hour lead time would provide opportunity to optimize stormwater capture and treatment operations, and minimize combined sewer overflows into the Bay.ussian River distributed hydrologic model.

Flood Control, Mississippi River, La Crosse, Wisconsin.

DTIC Science & Technology

1975-10-01

end SuP.,tifle) S TYPE OF REPORT & PERIOD COVEkr FINAL ENVIRONMENTAL IMPACT STATEMENT FLOOD CONTROL MISSISSIPPI RIVER LA CROSSE, WISCONSIN Pinal FIq 6...PERFORMING ORG. REPORT NUMBER 7. AUTHOR(e) 0 CONTRACT OR GRANT NUMBER( s ) 9 PERFORMING ORGANIZATION NAME AND ADrRESS 10. PROGRAM ELEMENT. PROJECT, T...rev s eflA ff r,,.e.. ind IdeInify by block rnmber) "-The proposed action is a flood control project consisting of levees, road raises, flood wall

The economic value of the flow regulation environmental service in a Brazilian urban watershed

NASA Astrophysics Data System (ADS)

Marques, Guilherme F.; de Souza, Verônica B. F. S.; Moraes, Natália V.

2017-11-01

Urban flood management have often focused either on the capacity expansion of drainage systems or on artificial detention storage. While flood control should take part early on urban planning, not enough is known to guide such plans and provide incentive to land use decisions that minimize the vulnerability to localized floods. In this paper, we offer a broader perspective on flood protection, by treating the original hydrologic flow regulation as an environmental service, and exploring how the value of this environmental service drives economic land use decisions that convert original (permeable) land into urbanized (impermeable). We investigate the relationship between land use decisions and their hydrologic consequences explicitly, and use this relationship to simulate resulting land use scenarios depending on the value attached to the environmental service of flow regulation. Rainfall-runoff simulation model results are combined to an optimization model based on two-stage stochastic programming approach to model economic land use decisions. The objective function maximizes the total expected land use benefit in an urban area, considering the opportunity cost of permeable areas in the first stage and the resulting loss of the environmental service of flow regulation on the second stage, under several probable hydrological events. A watershed in the city of Belo Horizonte, Brazil, is used to demonstrate the approach. Different values attached to the environmental service were tested, from zero to higher than the opportunity cost of land, and artificial detention infrastructure was included to calculate the resulting land use change and the loss in the environmental service value. Results indicate that by valuing the environmental service loss and discounting it from the economic benefits of land use, alternative solutions to land use are found, with decreased peak flows and lower flood frequency. Combined solutions including structural and non-structural techniques provide more cost effective results, avoiding both the depletion of the environmental service and the high opportunity cost associated to valuable commercial urban areas. Urban development under such premises will be more resilient and adapted to local flooding, instead of relying on increasingly expensive infrastructure.

Method of improving heterogeneous oil reservoir polymer flooding effect by positively-charged gel profile control

NASA Astrophysics Data System (ADS)

Zhao, Ling; Xia, Huifen

2018-01-01

The project of polymer flooding has achieved great success in Daqing oilfield, and the main oil reservoir recovery can be improved by more than 15%. But, for some strong oil reservoir heterogeneity carrying out polymer flooding, polymer solution will be inefficient and invalid loop problem in the high permeability layer, then cause the larger polymer volume, and a significant reduction in the polymer flooding efficiency. Aiming at this problem, it is studied the method that improves heterogeneous oil reservoir polymer flooding effect by positively-charged gel profile control. The research results show that the polymer physical and chemical reaction of positively-charged gel with the residual polymer in high permeability layer can generate three-dimensional network of polymer, plugging high permeable layer, and increase injection pressure gradient, then improve the effect of polymer flooding development. Under the condition of the same dosage, positively-charged gel profile control can improve the polymer flooding recovery factor by 2.3∼3.8 percentage points. Under the condition of the same polymer flooding recovery factor increase value, after positively-charged gel profile control, it can reduce the polymer volume by 50 %. Applying mechanism of positively-charged gel profile control technology is feasible, cost savings, simple construction, and no environmental pollution, therefore has good application prospect.

Long-lasting floods buffer the thermal regime of the Pampas

NASA Astrophysics Data System (ADS)

Houspanossian, Javier; Kuppel, Sylvain; Nosetto, Marcelo; Di Bella, Carlos; Oricchio, Patricio; Barrucand, Mariana; Rusticucci, Matilde; Jobbágy, Esteban

2018-01-01

The presence of large water masses influences the thermal regime of nearby land shaping the local climate of coastal areas by the ocean or large continental lakes. Large surface water bodies have an ephemeral nature in the vast sedimentary plains of the Pampas (Argentina) where non-flooded periods alternate with flooding cycles covering up to one third of the landscape for several months. Based on temperature records from 17 sites located 1 to 700 km away from the Atlantic coast and MODIS land surface temperature data, we explore the effects of floods on diurnal and seasonal thermal ranges as well as temperature extremes. In non-flooded periods, there is a linear increase of mean diurnal thermal range (DTR) from the coast towards the interior of the region (DTR increasing from 10 to 16 K, 0.79 K/100 km, r 2 = 0.81). This relationship weakens during flood episodes when the DTR of flood-prone inland locations shows a decline of 2 to 4 K, depending on surface water coverage in the surrounding area. DTR even approaches typical coastal values 500 km away from the ocean in the most flooded location that we studied during the three flooding cycles recorded in the study period. Frosts-free periods, a key driver of the phenology of both natural and cultivated ecosystems, are extended by up to 55 days during floods, most likely as a result of enhanced ground heat storage across the landscape ( 2.7 fold change in day-night heat transfer) combined with other effects on the surface energy balance such as greater night evaporation rates. The reduced thermal range and longer frost-free periods affect plant growth development and may offer an opportunity for longer crop growing periods, which may not only contribute to partially compensating for regional production losses caused by floods, but also open avenues for flood mitigation through higher plant evapotranspirative water losses.

Stability analysis of a run-of-river diversion hydropower plant with surge tank and spillway in the head pond.

PubMed

Sarasúa, José Ignacio; Elías, Paz; Martínez-Lucas, Guillermo; Pérez-Díaz, Juan Ignacio; Wilhelmi, José Román; Sánchez, José Ángel

2014-01-01

Run-of-river hydropower plants usually lack significant storage capacity; therefore, the more adequate control strategy would consist of keeping a constant water level at the intake pond in order to harness the maximum amount of energy from the river flow or to reduce the surface flooded in the head pond. In this paper, a standard PI control system of a run-of-river diversion hydropower plant with surge tank and a spillway in the head pond that evacuates part of the river flow plant is studied. A stability analysis based on the Routh-Hurwitz criterion is carried out and a practical criterion for tuning the gains of the PI controller is proposed. Conclusions about the head pond and surge tank areas are drawn from the stability analysis. Finally, this criterion is applied to a real hydropower plant in design state; the importance of considering the spillway dimensions and turbine characteristic curves for adequate tuning of the controller gains is highlighted.

Stability Analysis of a Run-of-River Diversion Hydropower Plant with Surge Tank and Spillway in the Head Pond

PubMed Central

Sarasúa, José Ignacio; Elías, Paz; Wilhelmi, José Román; Sánchez, José Ángel

2014-01-01

Run-of-river hydropower plants usually lack significant storage capacity; therefore, the more adequate control strategy would consist of keeping a constant water level at the intake pond in order to harness the maximum amount of energy from the river flow or to reduce the surface flooded in the head pond. In this paper, a standard PI control system of a run-of-river diversion hydropower plant with surge tank and a spillway in the head pond that evacuates part of the river flow plant is studied. A stability analysis based on the Routh-Hurwitz criterion is carried out and a practical criterion for tuning the gains of the PI controller is proposed. Conclusions about the head pond and surge tank areas are drawn from the stability analysis. Finally, this criterion is applied to a real hydropower plant in design state; the importance of considering the spillway dimensions and turbine characteristic curves for adequate tuning of the controller gains is highlighted. PMID:25405237

Examining the effects of urban agglomeration polders on flood events in Qinhuai River basin, China with HEC-HMS model.

PubMed

Gao, Yuqin; Yuan, Yu; Wang, Huaizhi; Schmidt, Arthur R; Wang, Kexuan; Ye, Liu

2017-05-01

The urban agglomeration polders type of flood control pattern is a general flood control pattern in the eastern plain area and some of the secondary river basins in China. A HEC-HMS model of Qinhuai River basin based on the flood control pattern was established for simulating basin runoff, examining the impact of urban agglomeration polders on flood events, and estimating the effects of urbanization on hydrological processes of the urban agglomeration polders in Qinhuai River basin. The results indicate that the urban agglomeration polders could increase the peak flow and flood volume. The smaller the scale of the flood, the more significant the influence of the polder was to the flood volume. The distribution of the city circle polder has no obvious impact on the flood volume, but has effect on the peak flow. The closer the polder is to basin output, the smaller the influence it has on peak flows. As the level of urbanization gradually improving of city circle polder, flood volumes and peak flows gradually increase compared to those with the current level of urbanization (the impervious rate was 20%). The potential change in flood volume and peak flow with increasing impervious rate shows a linear relationship.

Assessing water reservoir management and development in Northern Vietnam

NASA Astrophysics Data System (ADS)

Pianosi, F.; Quach, X.; Castelletti, A.; Soncini-Sessa, R.

2012-04-01

In many developing countries water is a key renewable resource to complement carbon-emitting energy production and support food security in the face of demand pressure from fast-growing industrial production and urbanization. To cope with undergoing changes, water resources development and management have to be reconsidered by enlarging their scope across sectors and adopting effective tools to analyze current and projected infrastructure potential and operation strategies. In this work we use multi-objective deterministic and stochastic optimization to assess the current reservoir operation and planned capacity expansion in the Red River Basin (Northern Vietnam), focusing on the major controllable infrastructure in the basin, the HoaBinh reservoir on the Da River. We first provide a general and mathematical description of the socio economic and physical system of the Red River Basin, including the three main objectives of hydropower production, flood control, and water supply, and using conceptual and data-driven modeling tools. Then, we analyze the historical operation of the HoaBinh reservoir and explore re-operation options corresponding to different tradeoffs among the three main objectives, using Multi-Objective Genetic Algorithm. Results show that there exist several operating policies that prove Pareto-dominant over the historical one, that is, they can improve all three management objectives simultaneously. However, while the improvement is rather significant with respect to hydropower production and water supply, it is much more limited in terms of flood control. To understand whether this is due to structural constraints (insufficient storing capacity) or to the imperfect information system (uncertainty in forecasting future flows and thus anticipate floods), we assessed the infrastructural system potential by application of Deterministic Dynamic Programming. Results show that the current operation can only be relatively improved by advanced optimization techniques, while investment should be put into enlarging the system storage capacity and exploiting additional information to inform the operation.

33 CFR 208.34 - Norman Dam and Lake Thunderbird, Little River, Okla.

Code of Federal Regulations, 2011 CFR

2011-07-01

... amounts to 76,600 acre-feet. Whenever the reservoir level is within this elevation range the flood control... flood damage below the reservoir. In order to accomplish this purpose, flood control releases shall be... of bankfull on the Little River downstream of the reservoir. Controlling bankfull stages and...

33 CFR 208.34 - Norman Dam and Lake Thunderbird, Little River, Okla.

Code of Federal Regulations, 2010 CFR

2010-07-01

... amounts to 76,600 acre-feet. Whenever the reservoir level is within this elevation range the flood control... flood damage below the reservoir. In order to accomplish this purpose, flood control releases shall be... of bankfull on the Little River downstream of the reservoir. Controlling bankfull stages and...

Nuclear reactor with makeup water assist from residual heat removal system

DOEpatents

Corletti, Michael M.; Schulz, Terry L.

1993-01-01

A pressurized water nuclear reactor uses its residual heat removal system to make up water in the reactor coolant circuit from an in-containment refueling water supply during staged depressurization leading up to passive emergency cooling by gravity feed from the refueling water storage tank, and flooding of the containment building. When depressurization commences due to inadvertence or a manageable leak, the residual heat removal system is activated manually and prevents flooding of the containment when such action is not necessary. Operation of the passive cooling system is not impaired. A high pressure makeup water storage tank is coupled to the reactor coolant circuit, holding makeup coolant at the operational pressure of the reactor. The staged depressurization system vents the coolant circuit to the containment, thus reducing the supply of makeup coolant. The level of makeup coolant can be sensed to trigger opening of successive depressurization conduits. The residual heat removal pumps move water from the refueling water storage tank into the coolant circuit as the coolant circuit is depressurized, preventing reaching the final depressurization stage unless the makeup coolant level continues to drop. The residual heat removal system can also be coupled in a loop with the refueling water supply tank, for an auxiliary heat removal path.

Nuclear reactor with makeup water assist from residual heat removal system

DOEpatents

Corletti, M.M.; Schulz, T.L.

1993-12-07

A pressurized water nuclear reactor uses its residual heat removal system to make up water in the reactor coolant circuit from an in-containment refueling water supply during staged depressurization leading up to passive emergency cooling by gravity feed from the refueling water storage tank, and flooding of the containment building. When depressurization commences due to inadvertence or a manageable leak, the residual heat removal system is activated manually and prevents flooding of the containment when such action is not necessary. Operation of the passive cooling system is not impaired. A high pressure makeup water storage tank is coupled to the reactor coolant circuit, holding makeup coolant at the operational pressure of the reactor. The staged depressurization system vents the coolant circuit to the containment, thus reducing the supply of makeup coolant. The level of makeup coolant can be sensed to trigger opening of successive depressurization conduits. The residual heat removal pumps move water from the refueling water storage tank into the coolant circuit as the coolant circuit is depressurized, preventing reaching the final depressurization stage unless the makeup coolant level continues to drop. The residual heat removal system can also be coupled in a loop with the refueling water supply tank, for an auxiliary heat removal path. 2 figures.

The Influence Of Antecedent Conditions On Flood Risk In Sub-Saharan Africa

NASA Astrophysics Data System (ADS)

Bischiniotis, K.

2017-12-01

Flood risk management has traditionally focused on long-term flood protection measures. However, due to high investment costs many lower-income countries are not able to afford hard infrastructure that provides the desired safety levels. Consequently, timely warning of not only extreme events is crucial in risk mitigation at these places. Most flood warning systems have predominantly focused on precipitation as the main predictive factor with lead times of hours or days. Nevertheless, other factors such as anomalous positive water storage, soil saturation and evapotranspiration also affect the flood build-up period. Gaining insights in the processes occurring during this period can increase warning lead times, resulting in more effective preparation. This study follows a pragmatic approach to analyse the hydro-meteorological pre-conditions of 501 damaging floods over the period 1980 to 2010 in sub-Saharan Africa. These are separated into a) weather scale (0-7 days) and b) seasonal scale conditions (up to 6 months) before each event in a way that the two periods do not overlap. The 7-day preceding precipitation (PRE7) and the Standardized Precipitation Evapotranspiration Index (SPEI) reflect the conditions in the two time scale domains, respectively. Using the flood onset date and the location derived from NatCatSERVICE database, the antecedent conditions of each flood are systematically compared to the same conditions during the other years of the dataset, during which no floods were reported. Results indicate that high PRE7 does not always justify the flood generation by itself since there were several cases where similar magnitude precipitation events did not lead to flooding. The SPEI in the end of the flood onset month seems to be a good flood monitoring tool as in most cases it well reflects the wet conditions (80% of the floods). The SPEIs of different averaging times prior to flood events also show that many floods were preceded by wet conditions (70% , 65%, and 57% for averaging time of 1, 3 and 6 months, respectively. Finally, we show that bringing together weather and seasonal-scale conditions can result in an increased flooding likelihood, which in turn might help humanitarian organizations and decision-makers extend the period of the preventive flood risk management planning.

Influence Assessment of Multiple Large-sized Reservoirs on Flooding in the Huai River Watershed, China

NASA Astrophysics Data System (ADS)

Wan, X. Y.

2017-12-01

The extensive constructions of reservoirs change the hydrologic characteristics of the associated watersheds, which obviously increases the complexity of watershed flood control decisions. By evaluating the impacts of the multi-reservoir system on the flood hydrograph, it becomes possible to improve the effectiveness of the flood control decisions. In this paper we compare the non-reservoir flood hydrograph with the actual observed flood hydrograph using the Lutaizi upstream of Huai river in East China as a representative case, where 20 large-scale/large-sized reservoirs have been built. Based on the total impact of the multi-reservoir system, a novel strategy, namely reservoir successively added (RSA) method, is presented to evaluate the contribution of each reservoir to the total impact. According each reservoir contribution, the "highly effective" reservoirs for watershed flood control are identified via hierarchical clustering. Moreover, we estimate further the degree of impact of the reservoir current operation rules on the flood hydrograph on the base of the impact of dams themselves. As a result, we find that the RSA method provides a useful method for analysis of multi-reservoir systems by partitioning the contribution of each reservoir to the total impacts on the flooding at the downstream section. For all the historical large floods examined, the multi-reservoir system in the Huai river watershed has a significant impact on flooding at the downstream Lutaizi section, on average reducing the flood volume and peak discharge by 13.92 × 108 m3 and 18.7% respectively. It is more informative to evaluate the maximum impact of each reservoir (on flooding at the downstream section) than to examine the average impact. Each reservoir has a different impact on the flood hydrograph at the Lutaizi section. In particular, the Meishan, Xianghongdian, Suyahu, Nanwan, Nianyushan and Foziling reservoirs exert a strong influence on the flood hydrograph, and are therefore important for flood control on the Huai river. Under the current operation rules, the volume and peak discharge of flooding at the Lutaizi section are reduced by 13.69 × 108m3 and 1429 m3/s respectively, accounting for 98% and 80.5% of the real reduction respectively.

An Analytical Method for Deriving Reservoir Operation Curves to Maximize Social Benefits from Multiple Uses of Water in the Willamette River Basin

NASA Astrophysics Data System (ADS)

Moore, K. M.; Jaeger, W. K.; Jones, J. A.

2013-12-01

A central characteristic of large river basins in the western US is the spatial and temporal disjunction between the supply of and demand for water. Water sources are typically concentrated in forested mountain regions distant from municipal and agricultural water users, while precipitation is super-abundant in winter and deficient in summer. To cope with these disparities, systems of reservoirs have been constructed throughout the West. These reservoir systems are managed to serve two main competing purposes: to control flooding during winter and spring, and to store spring runoff and deliver it to populated, agricultural valleys during the summer. The reservoirs also provide additional benefits, including recreation, hydropower and instream flows for stream ecology. Since the storage capacity of the reservoirs cannot be used for both flood control and storage at the same time, these uses are traded-off during spring, as the most important, or dominant use of the reservoir, shifts from buffering floods to storing water for summer use. This tradeoff is expressed in the operations rule curve, which specifies the maximum level to which a reservoir can be filled throughout the year, apart from real-time flood operations. These rule curves were often established at the time a reservoir was built. However, climate change and human impacts may be altering the timing and amplitude of flood events and water scarcity is expected to intensify with anticipated changes in climate, land cover and population. These changes imply that reservoir management using current rule curves may not match future societal values for the diverse uses of water from reservoirs. Despite a broad literature on mathematical optimization for reservoir operation, these methods are not often used because they 1) simplify the hydrologic system, raising doubts about the real-world applicability of the solutions, 2) exhibit perfect foresight and assume stationarity, whereas reservoir operators face uncertainty and risk daily, and 3) require complex computer programming. The proposed research addresses these critiques by pursuing a novel approach - the development of an analytical method to demonstrate how reservoir management could adapt to anticipated changes in water supply and demand, which incorporates some of the complexity of the hydrologic system, includes stochasticity, and can be readily implemented. Employing a normative economic framework of social welfare maximization, the research will 1) estimate the social benefits associated with reservoir uses, 2) analytically derive conditions for maximizing the benefits of reservoir operation, and 3) estimate the resulting optimal operating rules under future trajectories of climate, land cover, and population. The findings of this analysis will be used to address the following research questions: 1) How do the derived optimal operating rules compare to the existing rule curves? 2) How does the shape of the derived rule curves change under different scenarios of global change? 3) What is the change in net social benefits resulting from the use of these derived rule curves as compared to existing rule curves? 4) To the extent possible, what are the distributional and social justice implications of the derived changes in the rule curves?

The Charles River, Eastern Massachusetts: Scientific Information in Support of Environmental Restoration

USGS Publications Warehouse

Weiskel, Peter K.

2007-01-01

Human activity has profoundly altered the Charles River and its watershed over the past 375 years. Restoration of environmental quality in the watershed has become a high priority for private- and public-sector organizations across the region. The U.S. Environmental Protection Agency and the Massachusetts Executive Office of Environmental Affairs worked together to coordinate the efforts of the various organizations. One result of this initiative has been a series of scientific studies that provide critical information concerning some of the major hydrologic and ecological concerns in the watershed. These studies have focused upon: * Streamflows - Limited aquifer storage, growing water demands, and the spread of impervious surfaces are some of the factors exacerbating low summer streamflows in headwater areas of the watershed. Coordinated management of withdrawals, wastewater returns, and stormwater runoff could substantially increase low streamflows in the summer. Innovative approaches to flood control, including preservation of upstream wetland storage capacity and construction of a specially designed dam at the river mouth, have greatly reduced flooding in the lower part of the watershed in recent decades. * Water quality - Since the mid-1990s, the bacterial quality of the Charles River has improved markedly, because discharges from combined sewer overflows and the number of illicit sewer connections to municipal storm drains have been reduced. Improved management of stormwater runoff will likely be required, however, for full attainment of State and Federal water-quality standards. Phosphorus inputs from a variety of sources remain an important water-quality problem. * Fish communities and habitat quality - The Charles River watershed supports a varied fish community of about 20 resident and migratory species. Habitat conditions for fish and other aquatic species have improved in many parts of the river system in recent years. However, serious challenges remain, including the control of nutrients, algae, and invasive plants, mitigation of dam impacts, addressing remaining sources of bacteria to the river, and remediation of contaminated bottom habitat and the nontidal salt wedge in the lower river.

Peak Discharge, Flood Profile, Flood Inundation, and Debris Movement Accompanying the Failure of the Upper Reservoir at the Taum Sauk Pump Storage Facility near Lesterville, Missouri

USGS Publications Warehouse

Rydlund, Jr., Paul H.

2006-01-01

The Taum Sauk pump-storage hydroelectric power plant located in Reynolds County, Missouri, uses turbines that operate as pumps and hydraulic head generated by discharging water from an upper to a lower reservoir to produce electricity. A 55-acre upper reservoir with a 1.5- billion gallon capacity was built on top of Proffit Mountain, approximately 760 feet above the floodplain of the East Fork Black River. At approximately 5:16 am on December 14, 2005, a 680-foot wide section of the upper reservoir embankment failed suddenly, sending water rushing down the western side of Proffit Mountain and emptying into the floodplain of East Fork Black River. Flood waters from the upper reservoir flowed downstream through Johnson's Shut-Ins State Park and into the lower reservoir of the East Fork Black River. Floods such as this present unique challenges and opportunities to analyze and document peak-flow characteristics, flood profiles, inundation extents, and debris movement. On December 16, 2005, Light Detection and Ranging (LiDAR) data were collected and used to support hydraulic analyses, forensic failure analyses, damage extent, and mitigation of future disasters. To evaluate the impact of sedimentation in the lower reservoir, a bathymetric survey conducted on December 22 and 23, 2005, was compared to a previous bathymetric survey conducted in April, 2005. Survey results indicated the maximum reservoir capacity difference of 147 acre-feet existed at a pool elevation of 730 feet. Peak discharge estimates of 289,000 cubic feet per second along Proffit Mountain and 95,000 cubic feet per second along the East Fork Black River were determined through indirect measurement techniques. The magnitude of the embankment failure flood along the East Fork Black River was approximately 4 times greater than the 100-year flood frequency estimate of 21,900 cubic feet per second, and approximately 3 times greater than the 500-year flood frequency estimate of 30,500 cubic feet per second. Dynamic wave unsteady flow models Dam Break (DAMBRK) and Unsteady NETwork (UNET) were used to route the flood wave from the embankment failure breach of the upper reservoir to the spillway of the lower reservoir. Simulated velocities ranged from 20 to 51 feet per second along Proffit Mountain and 12 to 32 feet per second along the East Fork Black River. Simulated arrival time of the flood wave took approximately 5.5 to 6.0 minutes to enter into the floodplain of the East Fork Black River, and roughly 29 minutes to begin filling the lower reservoir. Simulated shear stress values reached as high as 232 pounds per square foot along the slope of Proffit Mountain and 144 pounds per square foot within the Shut-Ins. Flood depths from the embankment failure may have reached greater than 50 feet along Proffit Mountain and as much as 30 to 40 feet along the East Fork Black River. A steady-state model was used to develop 2-, 5-, 10-, 25-, 50-, 100-, and 500-year flood frequency profiles along the East Fork Black River. A similar flood event, hypothetically resulting from a breach of the east embankment above Taum Sauk Creek, was simulated along with the 100- and 500-year flood profiles on Taum Sauk Creek. Estimated extents of flood inundation were developed for each profile. Debris movement was extensive as a result of the flood wave moving down Proffit Mountain and through Johnson's Shut-Ins State Park. A quantitative assessment of debris movement was conducted to benefit rehabilitation efforts within the park. Approximately 180 acres of timber were affected as a result of the embankment failure flood.

10 CFR 1022.4 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-01-01

..., that is, a floodplain with a 1.0 percent chance of flooding in any given year. Critical action means..., but are not limited to, the storage of highly volatile, toxic, or water reactive materials. Critical..., technology, and implementation time. Preserve means to prevent modification to the natural floodplain or...

24 CFR 55.2 - Terminology.

Code of Federal Regulations, 2012 CFR

2012-04-01

... or inoperative during flood and storm events (e.g., data storage centers, generating plants... appropriate data sources.) (4) Floodway means that portion of the floodplain which is effective in carrying.... (See § 55.2(b)(1) for appropriate data sources.) (5) Functionally dependent use means a land use that...

Source-to-sink sediment transfers, environmental engineering and hazard mitigation in the steep Var River catchment, French Riviera, southeastern France

NASA Astrophysics Data System (ADS)

Anthony, Edward J.; Julian, Maurice

1999-12-01

Steep coastal margins are potentially subject to mass wasting processes involving notable landslide activity and sediment evacuation downstream by steep-gradient streams. Sediment transfer from short source-to-sink segments, coupled with mountain hydrological regimes, regulate patterns of river channel aggradation and coastal sediment supply in such geomorphic settings. On the steep French Riviera margin, sediment transfers from existing landslides or from various minor mass wasting processes to stream channels may result following bursts of heavy, concentrated rainfall. High-magnitude flooding and massive sediment transport downstream are generally related to unpredictable extreme rainfalls. Both mass movements and channel sediment storage pose serious hazards to downvalley settlements and infrastructure. A consideration of channel sediment storage patterns in the Var River catchment, the most important catchment in this area, highlights two important shortcomings relative to environmental engineering and hazard mitigation practices. In the first place, the appreciation of geomorphic processes is rather poor. This is illustrated by the undersized nature of engineering works constructed to mitigate hazards in the upstream bedload-dominated channels, and by the unforeseen effects that ten rock dams, constructed in the early 1970s, have had on downstream and coastal sediment storage and on sediment dispersal patterns and, consequently, valley flooding. Secondly, planners and environmental engineers have lacked foresight in valley and coastal management issues on this steep setting, notably as regards the reclaimed areas of the lower Var channel and delta liable to flooding. Urbanization and transport and environmental engineering works have progressively affected patterns of storage and transport of fine-grained sediments in the lower Var channel and delta. Meanwhile the problems raised by these changes have not been adequately addressed in terms of scientific research. A necessary future step in bettering the engineering solutions implemented to contain natural hazards or to harness water and sediment resources is that of fine-scale analysis of source-to-sink sediment transfer processes, of sediment budgets, of time-scales of storage in stream channels, and, finally, of high-magnitude hydrometeorological forcing events in this area. The way all these aspects have been modulated by engineering practices and socioeconomic development should also be an important part of such an analysis.

Quantifying uncertainty in morphologically-derived bedload transport rates for large braided rivers: insights from high-resolution, high-frequency digital elevation model differencing

NASA Astrophysics Data System (ADS)

Brasington, J.; Hicks, M.; Wheaton, J. M.; Williams, R. D.; Vericat, D.

2013-12-01

Repeat surveys of channel morphology provide a means to quantify fluvial sediment storage and enable inferences about changes in long-term sediment supply, watershed delivery and bed level adjustment; information vital to support effective river and land management. Over shorter time-scales, direct differencing of fluvial terrain models may also offer a route to predict reach-averaged sediment transport rates and quantify the patterns of channel morphodynamics and the processes that force them. Recent and rapid advances in geomatics have facilitated these goals by enabling the acquisition of topographic data at spatial resolutions and precisions suitable for characterising river morphology at the scale of individual grains over multi-kilometre reaches. Despite improvements in topographic surveying, inverting the terms of the sediment budget to derive estimates of sediment transport and link these to morphodynamic processes is, nonetheless, often confounded by limited knowledge of either the sediment supply or efflux across a boundary of the control volume, or unobserved cut-and-fill taking place between surveys. This latter problem is particularly poorly constrained, as field logistics frequently preclude surveys at a temporal frequency sufficient to capture changes in sediment storage associated with each competent event, let alone changes during individual floods. In this paper, we attempt to quantify the principal sources of uncertainty in morphologically-derived bedload transport rates for the large, labile, gravel-bed braided Rees River which drains the Southern Alps of NZ. During the austral summer of 2009-10, a unique timeseries of 10 high quality DEMs was derived for a 3 x 0.7 km reach of the Rees, using a combination of mobile terrestrial laser scanning, aDcp soundings and aerial image analysis. Complementary measurements of the forcing flood discharges and estimates of event-based particle step lengths were also acquired during the field campaign. Together, the resulting dataset quantifies the evolution of the study reach over an annual flood season and provides an unprecedented insight into the patterns and processes of braiding. Uncertainties in the inferred rates of bedload transport are associated with the temporal and spatial frequency of measurements used to estimate the storage term of the sediment budget, and methods used to derive the boundary sediment flux. Results obtained reveal that over the annual flood season, over 80% of the braidplain was mobilised and that more than 50% of the bed experienced multiple cycles of cut and fill. Integration of cut and fill volumes event-by-event were found to be approximately 300% of the net change between October and May. While significant uncertainties reside in estimates of the boundary flux, rates of bedload transport derived for individual events are shown to correlate well with total energy expenditure and suggest that a relatively simple relationship may exist between the driving hydraulic forces at the reach scale and the geomorphic work performed.

Formation and evolution of valley-bottom and channel features, Lower Deschutes River, Oregon

USGS Publications Warehouse

Curran, Janet H.; O'Conner, Jim E.; O'Conner, Jim E.; Grant, Gordon E.

2003-01-01

Primary geologic and geomorphic processes that formed valley-bottom and channel features downstream from the Pelton-Round Butte dam complex are inferred from a canyon-long analysis of feature morphology, composition, location, and spatial distribution. Major controls on valley-bottom morphology are regional tectonics, large landslides, and outsized floods (floods with return periods greater than 1000 yrs), which include the late Holocene Outhouse Flood and several Quaternary landslide dam failures. Floods with a return period on the order of 100 yrs, including historical floods in 1996, 1964, and 1861, contribute to fan building and flood plain formation only within the resistant framework established by the major controls. Key processes in the formation of channel features, in particular the 153 islands and 23 large rapids, include long-term bedrock erosion, outsized floods, and century-scale floods. Historical analysis of channel conditions since 1911 indicates that the largest islands, which are cored by outsized-flood deposits, locally control channel location, although their margins are substantially modified during annual- to century-scale floods. Islands cored by bedrock have changed little. Islands formed by annual- to century-scale floods are more susceptible to dynamic interactions between tributary sediment inputs, mainstem flow hydraulics, and perhaps riparian vegetation. Temporal patterns of island change in response to the sequence of 20th century flooding indicate that many islands accreted sediment during annual- to decadal-scale floods, but eroded during larger century-scale floods. There is, however, no clear trend of long-term changes in patterns of island growth, movement, or erosion either spatially or temporally within the lower Deschutes River.

Alternating flood and drought hazards in the Drava Plain, Hungary

NASA Astrophysics Data System (ADS)

Lóczy, Dénes; Dezsö, József; Gyenizse, Péter; Ortmann-Ajkai, Adrienne

2016-04-01

Our research project covers the assessment of archive data and monitoring present-day water availability in the floodplain of the Hungarian Drava River. Historically flood hazard has been prevalent in the area. Recently, however, flood and drought hazards occur with equal frequency. Potential floodwater storage is defined from the analyses of soil conditions (grain size, porosity, water conductivity etc.) and GIS-based volumetric estimations of storage capacities in oxbows (including communication with groundwater). With the remarkable rate of river channel incision (2.4 m per century) and predictable climate change trends (increased annual mean temperature and decreased summer precipitation), the growing frequency and intensification of drought hazard is expected. For the assessment of drought hazard the impacts of hydrometeorological events, groundwater table dynamics and capillary rise are modelled, the water demands of natural vegetation and agricultural crops are studied. The project is closely linked to the ongoing Old Drava Programme, a comprehensive government project, which envisions floodplain rehabilitation through major transformations in water governance and land use of the region, and has numerous implications for regional development. Authors are grateful for financial support from the Hungarian National Scientific Research Fund (OTKA, contacts nos K 104552 and K 108755) as well as from the Visegrad Fund (31210058). The contribution is dedicated to the 650th anniversary of the foundation of the University of Pécs, Hungary.

An inventory of published and unpublished fluvial-sediment data for California, 1956-70

USGS Publications Warehouse

Porterfield, George

1972-01-01

This inventory was prepared to provide a convenient reference to published and unpublished fluvial-sediment data for water years 1956-70, and updates substantially previous inventories. Sediment stations are listed in downstream order, and an alphabetical list of stations is also included. Figure 1 shows the approximate location of sediment stations in California. Most of the fluvial-sediment data in California were collected by the U.S. Geological Survey, under cooperative agreements with the following Federal, State, and local agencies: California Department of Water Resources, California Department of Navigation and Ocean Development, California Department of Fish and Game, Bolinas Harbor District, Monterey County Flood Control and Water Conservation District, Orange County Flood Control District, Riverside County Flood Control and Water Conservation District, San Diego County Department of Sanitation and Flood Control, San Luis Obispo County, San Mateo County, Santa Clara County Flood Control and Water District, Santa Cruz County Flood Control and Water Conservation District, Santa Cruz, city of, University of California, Ventura County Flood Control District, Forest Service, U.S. Department of Agriculture, Soil Conservation Service, U.S. Department of Agriculture, Corps of Engineers, U.S. Army, Bureau of Reclamation, U.S. Department of the Interior, National Park Service, U.S. Department of the Interior. This report was prepared by the Geological Survey under the general supervision of R. Stanley Lord, district chief in charge of water-resources investigations in California.

Why continuous simulation? The role of antecedent moisture in design flood estimation

NASA Astrophysics Data System (ADS)

Pathiraja, S.; Westra, S.; Sharma, A.

2012-06-01

Continuous simulation for design flood estimation is increasingly becoming a viable alternative to traditional event-based methods. The advantage of continuous simulation approaches is that the catchment moisture state prior to the flood-producing rainfall event is implicitly incorporated within the modeling framework, provided the model has been calibrated and validated to produce reasonable simulations. This contrasts with event-based models in which both information about the expected sequence of rainfall and evaporation preceding the flood-producing rainfall event, as well as catchment storage and infiltration properties, are commonly pooled together into a single set of "loss" parameters which require adjustment through the process of calibration. To identify the importance of accounting for antecedent moisture in flood modeling, this paper uses a continuous rainfall-runoff model calibrated to 45 catchments in the Murray-Darling Basin in Australia. Flood peaks derived using the historical daily rainfall record are compared with those derived using resampled daily rainfall, for which the sequencing of wet and dry days preceding the heavy rainfall event is removed. The analysis shows that there is a consistent underestimation of the design flood events when antecedent moisture is not properly simulated, which can be as much as 30% when only 1 or 2 days of antecedent rainfall are considered, compared to 5% when this is extended to 60 days of prior rainfall. These results show that, in general, it is necessary to consider both short-term memory in rainfall associated with synoptic scale dependence, as well as longer-term memory at seasonal or longer time scale variability in order to obtain accurate design flood estimates.

Flood risk trends in coastal watersheds in South Spain: direct and indirect impact of river regulation

NASA Astrophysics Data System (ADS)

Egüen, M.; Polo, M. J.; Gulliver, Z.; Contreras, E.; Aguilar, C.; Losada, M. A.

2015-06-01

Spain is one of the world's countries with a large number of reservoirs per inhabitant. This intense regulation of the fluvial network during the 20th century has resulted in a decrease in flood events, a higher availability of water resources, and a high development of the irrigated crop area, even in the drier regions. For decades, flood perception was reduced since the development of reservoirs protected the floodplains of river; this resulted in later occupation of soil by urban, agricultural and industrial uses. In recent years, an increasing perception of flood events is observed, associated to the higher damage associated to extreme events in the now occupied areas, especially in coastal watersheds. This work shows the change on flood risk in the coastal areas of three hydrographic basins in Andalusia (South Spain) during the reservoir expansion period: the Guadalete, Guadalquivir and Guadalhorce river basins. The results differentiate the impact of the regulation level on both the cumulative distribution functions of the fluvial discharge near the river mouth, for different time scales, and the associated damage related to the enhanced soil occupation during this period. The different impact on the final medium and long term flood risk is also assessed in terms of the storage capacity per unit area throughout the basins, the effective annual runoff/precipitation index, the frequency of sea storms, and the human factor (change in social perception of floods), for different intervals in the flood extreme regime. The implications for adaptation actions is also assessed.

Determining which land management practices reduce catchment scale flood risk and where to implement them for optimum effect

NASA Astrophysics Data System (ADS)

Pattison, Ian; Lane, Stuart; Hardy, Richard; Reaney, Sim

2010-05-01

The theoretical basis for why changes in land management might increase flood risk are well known, but proving them through numerical modelling still remains a challenge. In large catchments, like the River Eden in Cumbria, NW England, one of the reasons for this is that it is unfeasible to test multiple scenarios in all their possible locations. We have developed two linked approaches to refine the number of scenarios and locations using 1) spatial downscaling and 2) participatory decision making, which potentially should increase the likelihood of finding a link between land use and downstream flooding. Firstly, land management practices can have both flood reducing and flood increasing effects, depending on their location. As a result some areas of the catchment are more important in determining downstream flood risk than others, depending on the land use and hydrological connectivity. We apply a downscaling approach to identify which sub-catchments are most important in explaining downstream flooding. This is important because it is in these areas that management options are most likely to have a positive and detectable effect. Secondly, once the dominant sub-catchment has been identified, the land management scenarios that are both feasible and likely to impact flood risk need to be determined. This was done through active stakeholder engagement. The stakeholder group undertook a brainstorming exercise, which suggested about 30 different rural land management scenarios, which were mapped on to a literature-based conceptual framework of hydrological processes. Then these options were evaluated based on five criteria: relevance to catchment, scientific effectiveness, testability, robustness/uncertainty and feasibility of implementation. The suitability of each scenario was discussed and prioritised by the stakeholder group based on scientific needs and expectations and local suitability and feasibility. The next stage of the participatory approach was a mapping workshop, whereby a map of the catchment was laid out and locations where each scenario could feasibly be implemented were drawn on. This was combined with an analysis of historical maps to identify past land covers and a catchment walkover survey to put modelling work in the real world context. The land management scenarios were tested using hydrological and hydraulic models. Landscape scale changes, such as the effects of compaction and afforestation were tested using a catchment scale hydrological mode, CRUM2D. Channel scale changes, such as re-meandering and floodplain storage were tested using the 1D hydraulic model, iSIS, by altering channel cross sections and creating spills between the channel and floodplain. It is expected that the channel modification and floodplain storage scenarios will have the greatest impact on flooding both at the local and catchment scales. The landscape scale changes are more diffuse and therefore their impact is expected to be less significant. Although, early analysis indicates that the spatial location of changes strongly influences their effect on flooding.

The influence of antecedent conditions on flood risk in sub-Saharan Africa

NASA Astrophysics Data System (ADS)

Bischiniotis, Konstantinos; van den Hurk, Bart; Coughlan de Perez, Erin; Jongman, Brenden; Veldkamp, Ted; Aerts, Jeroen

2017-04-01

Traditionally, flood risk management has focused on long-term flood protection measures. However, many countries are often not able to afford hard infrastructure that provides sufficient safety levels due to the high investment costs. As a consequence, they rely more on post disaster response and timely warning systems. Most early warning systems have predominantly focused on precipitation as the main predictive factor, having usually lead times of hours or days. However, other variables could also play a role. For instance, anomalous positive water storage, soil saturation and evapotranspiration are physical factors that may influence the length of the flood build-up period. This period can vary from some days to several months before the event and it is particularly important in flood risk management since longer flood warning lead times during this period could result in better flood preparation actions. This study addresses how the antecedent conditions of historical reported flood events over the period 1980 to 2010 in sub-Saharan Africa relate to flood generation. The seasonal-scale conditions are reflected in the Standardized Precipitation Evapotranspiration Index (SPEI), which is calculated using monthly precipitation and temperature data and accounts for the wetness/dryness of an area. Antecedent conditions are separated into a) a short term 'weather-scale' period (0-7 days) and b) a 'seasonal-scale' period (up to 6 months) before the flood event in such a way that they do not overlap. Total 7-day precipitation, which is based on daily meteorological data, was used to evaluate the short-term weather-scale conditions. Using a pair of coordinates, derived from the NatCatSERVICE database on global flood losses, each flood event is positioned on a 0.5°x 0.5° grid cell. The antecedent SPEI conditions of the two periods and their joint influence in flood generation are compared to the same period conditions of the other years of the dataset. First results revealed that many floods were preceded by high SPEI for several months before the flooding event, showing that the area was saturated with a long lead-time. Those that were not preceded by high SPEI had very extreme short-term precipitation that caused the flood event. Furthermore, the importance of seasonal-scale conditions is quantified, which in turn might help humanitarian organizations and decision-makers extend the period of the preventive flood risk management planning.

76 FR 19753 - Intent To Prepare a Draft Environmental Impact Statement for the `Īao Stream Flood Control...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-08

... Environmental Impact Statement for the `[Imacr]ao Stream Flood Control Project, Wailuku, Maui, HI AGENCY... Project, Wailuku, Maui, HI. This effort is being proposed under Section 203 of the Flood Control Act of...), Building 230, Fort Shafter, HI 96858- 5440. Submit electronic comments to [email protected] . FOR...

33 CFR 263.24 - Authority for snagging and clearing for flood control (Section 208).

Code of Federal Regulations, 2010 CFR

2010-07-01

... clearing for flood control (Section 208). 263.24 Section 263.24 Navigation and Navigable Waters CORPS OF... Policy § 263.24 Authority for snagging and clearing for flood control (Section 208). (a) Legislative... 26 of the Water Resources Development Act approved March 7, 1974 states: The Secretary of the Army is...

Determining CO2 storage potential during miscible CO2 enhanced oil recovery: Noble gas and stable isotope tracers

USGS Publications Warehouse

Shelton, Jenna L.; McIntosh, Jennifer C.; Hunt, Andrew; Beebe, Thomas L; Parker, Andrew D; Warwick, Peter D.; Drake, Ronald; McCray, John E.

2016-01-01

Rising atmospheric carbon dioxide (CO2) concentrations are fueling anthropogenic climate change. Geologic sequestration of anthropogenic CO2 in depleted oil reservoirs is one option for reducing CO2 emissions to the atmosphere while enhancing oil recovery. In order to evaluate the feasibility of using enhanced oil recovery (EOR) sites in the United States for permanent CO2 storage, an active multi-stage miscible CO2flooding project in the Permian Basin (North Ward Estes Field, near Wickett, Texas) was investigated. In addition, two major natural CO2 reservoirs in the southeastern Paradox Basin (McElmo Dome and Doe Canyon) were also investigated as they provide CO2 for EOR operations in the Permian Basin. Produced gas and water were collected from three different CO2 flooding phases (with different start dates) within the North Ward Estes Field to evaluate possible CO2 storage mechanisms and amounts of total CO2retention. McElmo Dome and Doe Canyon were sampled for produced gas to determine the noble gas and stable isotope signature of the original injected EOR gas and to confirm the source of this naturally-occurring CO2. As expected, the natural CO2produced from McElmo Dome and Doe Canyon is a mix of mantle and crustal sources. When comparing CO2 injection and production rates for the CO2 floods in the North Ward Estes Field, it appears that CO2 retention in the reservoir decreased over the course of the three injections, retaining 39%, 49% and 61% of the injected CO2 for the 2008, 2010, and 2013 projects, respectively, characteristic of maturing CO2 miscible flood projects. Noble gas isotopic composition of the injected and produced gas for the flood projects suggest no active fractionation, while δ13CCO2 values suggest no active CO2dissolution into formation water, or mineralization. CO2 volumes capable of dissolving in residual formation fluids were also estimated along with the potential to store pure-phase supercritical CO2. Using a combination of dissolution trapping and residual trapping, both volumes of CO2 currently retained in the 2008 and 2013 projects could be justified, suggesting no major leakage is occurring. These subsurface reservoirs, jointly considered, have the capacity to store up to 9 years of CO2 emissions from an average US powerplant.

Natural flood risk management in flashy headwater catchments: managing runoff peaks, timing, water quality and sediment regimes

NASA Astrophysics Data System (ADS)

Wilkinson, Mark; Addy, Steve; Ghimire, Sohan; Kenyon, Wendy; Nicholson, Alex; Quinn, Paul; Stutter, Marc; Watson, Helen

2013-04-01

Over the past decade many European catchments have experienced an unusually high number of flood events. A large number of these events are the result of intense rainfall in small headwater catchments which are dominated by surface runoff generation, resulting in flash flooding of local communities. Soil erosion and related water quality issues, among others, are typically associated with such rapid runoff generation. The hazard of flooding is increasing owing to impacts of changing climatic patterns (including more intense summer storms), intensification of agriculture within rural catchments and continued pressure to build on floodplains. Concurrently, the cost of constructing and maintaining traditional flood defences in small communities outweigh the potential benefits. Hence, there is a growing interest in more cost effective natural approaches that also have multipurpose benefits in terms of sediment, water quality, and habitat creation. Many catchments in Europe are intensively farmed and there is great potential for agriculture to be part of the solution to flood risk management. Natural flood management (NFM) is the alteration, restoration or use of landscape features with the aim of reducing flood risk by slowing down, storing (and filtering) rapid surface runoff. NFM includes measures such as temporarily storing water in ponds/wetlands, increasing soil infiltration, planting trees on floodplains and within catchments, re-meandering and wood placements in streams/ditches. In this presentation we highlight case studies from densely instrumented research sites across the UK (which could be typical of many European catchments) where NFM measures have been installed in small scale flashy catchments. The presentation will give an overview of the function of these measures in these catchments and how other multiple benefits are being accrued. Study catchments include the headwater catchments of the Bowmont (3 to 8 km2) and Belford Burn (6 km2) catchments. These catchments are known for their rapid runoff generation and have downstream local communities at risk of flash flooding. In Bowmont, NFM measures are currently being put in place to restore river bars and to store water more effectively on the flood plains during these flashy events. For example, Apex engineered wood structure in the river channel and riparian zones are designed to trap sediment and log bank protection structures are being installed to stop bank erosion. Tree planting in the catchment is also taking place. In the Belford catchment storage ponds and woody debris have been installed over the past five years to help to reduce the flood risk to the village of Belford. A dense instrumentation network has provided data for analysis and modelling which shows evidence of local scale flood peak reductions along with the collection of large amounts of sediment. A modelling study carried out (using a pond network model) during an intense summer storm showed that 30 small scale pond features used in sequence could reduce the flood peak by ~35% at the local scale. Findings show that managing surface runoff and local ditch flow at local scale headwater catchments is a cost effective way of managing flashy catchment for flood risk and sediment control. Working with catchment stakeholders is vital. Information given by the local community post flooding has been useful in placing NFM measures throughout the catchments. Involving the local communities in these projects and giving them access to the data and model outputs has helped to develop these projects further.

Radar-based Quantitative Precipitation Forecasting using Spatial-scale Decomposition Method for Urban Flood Management

NASA Astrophysics Data System (ADS)

Yoon, S.; Lee, B.; Nakakita, E.; Lee, G.

2016-12-01

Recent climate changes and abnormal weather phenomena have resulted in increased occurrences of localized torrential rainfall. Urban areas in Korea have suffered from localized heavy rainfall, including the notable Seoul flood disaster in 2010 and 2011. The urban hydrological environment has changed in relation to precipitation, such as reduced concentration time, a decreased storage rate, and increased peak discharge. These changes have altered and accelerated the severity of damage to urban areas. In order to prevent such urban flash flood damages, we have to secure the lead time for evacuation through the improvement of radar-based quantitative precipitation forecasting (QPF). The purpose of this research is to improve the QPF products using spatial-scale decomposition method for considering the life time of storm and to assess the accuracy between traditional QPF method and proposed method in terms of urban flood management. The layout of this research is as below. First, this research applies the image filtering to separate the spatial-scale of rainfall field. Second, the separated small and large-scale rainfall fields are extrapolated by each different forecasting method. Third, forecasted rainfall fields are combined at each lead time. Finally, results of this method are evaluated and compared with the results of uniform advection model for urban flood modeling. It is expected that urban flood information using improved QPF will help to reduce casualties and property damage caused by urban flooding through this research.

Assessing sedimentation issues within aging flood-control reservoirs

USDA-ARS?s Scientific Manuscript database

Flood control reservoirs designed and built by federal agencies have been extremely effective in reducing the ravages of floods nationwide. Yet some structures are being removed for a variety of reasons, while other structures are aging rapidly and require either rehabilitation or decommissioning. ...

Urban sprawl and flooding in southern California

USGS Publications Warehouse

Rantz, S.E.

1970-01-01

The floods of January 1969 in south-coastal California provide a timely example of the effect of urban sprawl on flood damage. Despite recordbreaking, or near recordbreaking, stream discharges, damage was minimal in the older developed areas that are protected against inundation and debris damage by carefully planned flood-control facilities, including debris basins and flood-conveyance channels. By contrast, heavy damage occurred in areas of more recent urban sprawl, where the hazards of inundation and debris or landslide damage have not been taken into consideration, and where the improvement and development of drainage or flood-control facilities have not kept pace with expanding urbanization.

Urban Flood Prevention and Early Warning System in Jinan City

NASA Astrophysics Data System (ADS)

Feng, Shiyuan; Li, Qingguo

2018-06-01

The system construction of urban flood control and disaster reduction in China is facing pressure and challenge from new urban water disaster. Under the circumstances that it is difficult to build high standards of flood protection engineering measures in urban areas, it is particularly important to carry out urban flood early warning. In Jinan City, a representative inland area, based on the index system of early warning of flood in Jinan urban area, the method of fuzzy comprehensive evaluation was adopted to evaluate the level of early warning. Based on the cumulative rainfall of 3 hours, the CAflood simulation results based on cellular automaton model of urban flooding were used as evaluation indexes to realize the accuracy and integration of urban flood control early warning.

Do Natural Disasters Affect Voting Behavior? Evidence from Croatian Floods

PubMed Central

Bovan, Kosta; Banai, Benjamin; Pavela Banai, Irena

2018-01-01

Introduction: Studies show that natural disasters influence voters’ perception of incumbent politicians. To investigate whether voters are prone to punish politicians for events that are out of their control, this study was conducted in the previously unstudied context of Croatia, and by considering some of the methodological issues of previous studies. Method: Matching method technique was used, which ensures that affected and non-affected areas are matched on several control variables. The cases of natural disaster in the present study were floods that affected Croatia in 2014 and 2015. Results: Main results showed that, prior to matching, floods had an impact on voting behaviour in the 2014 and 2015 elections. Voters from flooded areas decreased their support for the incumbent government and president in the elections following the floods. However, once we accounted for differences in control variables between flooded and non-flooded areas, the flood effect disappeared. Furthermore, results showed that neither the presence nor the amount of the government’s relief spending had an impact on voting behaviour. Discussion: Presented results imply that floods did not have an impact on the election outcome. Results are interpreted in light of the retrospective voter model. PMID:29770268

Hospital infection prevention and control issues relevant to extensive floods.

PubMed

Apisarnthanarak, Anucha; Mundy, Linda M; Khawcharoenporn, Thana; Glen Mayhall, C

2013-02-01

The devastating clinical and economic implications of floods exemplify the need for effective global infection prevention and control (IPC) strategies for natural disasters. Reopening of hospitals after excessive flooding requires a balance between meeting the medical needs of the surrounding communities and restoration of a safe hospital environment. Postflood hospital preparedness plans are a key issue for infection control epidemiologists, healthcare providers, patients, and hospital administrators. We provide recent IPC experiences related to reopening of a hospital after extensive black-water floods necessitated hospital closures in Thailand and the United States. These experiences provide a foundation for the future design, execution, and analysis of black-water flood preparedness plans by IPC stakeholders.

Frequency of floods from a burned chaparral watershed

Treesearch

Iraj Nasseri

1989-01-01

Effects of brush fire on hydrologic characteristics of chaparral watersheds were analyzed. An unburned chaparral produces moderate surface runoff. The vegetation promotes infiltration by retarding the runoff and providing temporary storage during intense rainfall. The hydrologic characteristics of chaparral watershed, however, are drastically changed by fires. The high...

12 CFR 572.2 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-01-01

... zoning and building code jurisdiction over a particular area having special flood hazards. (e) Designated loan means a loan secured by a building or mobile home that is located or to be located in a special...) Building means a walled and roofed structure, other than a gas or liquid storage tank, that is principally...

Soil water improvements with the long-term use of a winter rye cover crop

USDA-ARS?s Scientific Manuscript database

The Midwestern United States is projected to experience increasing rainfall variability. One approach to mitigate climate impacts is to utilize crop and soil management practices that enhance soil water storage, reducing the risks of flooding as well as drought-induced crop water stress. While some ...

A probabilistic approach to modeling postfire erosion after the 2009 australian brushfires

USDA-ARS?s Scientific Manuscript database

Major concerns after bushfires and wildfires include increased flooding, erosion and debris flows due to loss of the protective forest floor layer, loss of water storage, and creation of water repellent soil conditions. To assist postfire assessment teams in their efforts to evaluate fire effects an...

Flood control surveys in the northeast

Treesearch

Arthur Bevan

1947-01-01

Floods are a grave danger to our Nation's resources. It is estimated that floods cost the United States at least $100 million every year. The recent Mississippi floods, which dramatically brought the seriousness of the situation to public attention, cost half a billion dollars in direct-damages. The Northeast carries a heavy burden of flood losses. In 1936, floods...

33 CFR 203.41 - General.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Control Works Damaged by Flood or Coastal Storm: The Corps Rehabilitation and Inspection Program § 203.41... constructed hurricane/shore protection projects. (b) Implementation of authority. The Rehabilitation and... projects damaged by floods and coastal storm events. The RIP consists of a process to inspect flood control...

33 CFR 203.41 - General.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Control Works Damaged by Flood or Coastal Storm: The Corps Rehabilitation and Inspection Program § 203.41... constructed hurricane/shore protection projects. (b) Implementation of authority. The Rehabilitation and... projects damaged by floods and coastal storm events. The RIP consists of a process to inspect flood control...

33 CFR 203.41 - General.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Control Works Damaged by Flood or Coastal Storm: The Corps Rehabilitation and Inspection Program § 203.41... constructed hurricane/shore protection projects. (b) Implementation of authority. The Rehabilitation and... projects damaged by floods and coastal storm events. The RIP consists of a process to inspect flood control...

33 CFR 203.41 - General.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Control Works Damaged by Flood or Coastal Storm: The Corps Rehabilitation and Inspection Program § 203.41... constructed hurricane/shore protection projects. (b) Implementation of authority. The Rehabilitation and... projects damaged by floods and coastal storm events. The RIP consists of a process to inspect flood control...

33 CFR 203.41 - General.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Control Works Damaged by Flood or Coastal Storm: The Corps Rehabilitation and Inspection Program § 203.41... constructed hurricane/shore protection projects. (b) Implementation of authority. The Rehabilitation and... projects damaged by floods and coastal storm events. The RIP consists of a process to inspect flood control...

Modeling multi-source flooding disaster and developing simulation framework in Delta

NASA Astrophysics Data System (ADS)

Liu, Y.; Cui, X.; Zhang, W.

2016-12-01

Most Delta regions of the world are densely populated and with advanced economies. However, due to impact of the multi-source flooding (upstream flood, rainstorm waterlogging, storm surge flood), the Delta regions is very vulnerable. The academic circles attach great importance to the multi-source flooding disaster in these areas. The Pearl River Delta urban agglomeration in south China is selected as the research area. Based on analysis of natural and environmental characteristics data of the Delta urban agglomeration(remote sensing data, land use data, topographic map, etc.), hydrological monitoring data, research of the uneven distribution and process of regional rainfall, the relationship between the underlying surface and the parameters of runoff, effect of flood storage pattern, we use an automatic or semi-automatic method for dividing spatial units to reflect the runoff characteristics in urban agglomeration, and develop an Multi-model Ensemble System in changing environment, including urban hydrologic model, parallel computational 1D&2D hydrodynamic model, storm surge forecast model and other professional models, the system will have the abilities like real-time setting a variety of boundary conditions, fast and real-time calculation, dynamic presentation of results, powerful statistical analysis function. The model could be optimized and improved by a variety of verification methods. This work was supported by the National Natural Science Foundation of China (41471427); Special Basic Research Key Fund for Central Public Scientific Research Institutes.

Frameworks for amending reservoir water management

USGS Publications Warehouse

Mower, Ethan; Miranda, Leandro E.

2013-01-01

Managing water storage and withdrawals in many reservoirs requires establishing seasonal targets for water levels (i.e., rule curves) that are influenced by regional precipitation and diverse water demands. Rule curves are established as an attempt to balance various water needs such as flood control, irrigation, and environmental benefits such as fish and wildlife management. The processes and challenges associated with amending rule curves to balance multiuse needs are complicated and mostly unfamiliar to non-US Army Corps of Engineers (USACE) natural resource managers and to the public. To inform natural resource managers and the public we describe the policies and process involved in amending rule curves in USACE reservoirs, including 3 frameworks: a general investigation, a continuing authority program, and the water control plan. Our review suggests that water management in reservoirs can be amended, but generally a multitude of constraints and competing demands must be addressed before such a change can be realized.

Assessing the impact of climate and land use changes on extreme floods in a large tropical catchment

NASA Astrophysics Data System (ADS)

Jothityangkoon, Chatchai; Hirunteeyakul, Chow; Boonrawd, Kowit; Sivapalan, Murugesu

2013-05-01

In the wake of the recent catastrophic floods in Thailand, there is considerable concern about the safety of large dams designed and built some 50 years ago. In this paper a distributed rainfall-runoff model appropriate for extreme flood conditions is used to generate revised estimates of the Probable Maximum Flood (PMF) for the Upper Ping River catchment (area 26,386 km2) in northern Thailand, upstream of location of the large Bhumipol Dam. The model has two components: a continuous water balance model based on a configuration of parameters estimated from climate, soil and vegetation data and a distributed flood routing model based on non-linear storage-discharge relationships of the river network under extreme flood conditions. The model is implemented under several alternative scenarios regarding the Probable Maximum Precipitation (PMP) estimates and is also used to estimate the potential effects of both climate change and land use and land cover changes on the extreme floods. These new estimates are compared against estimates using other hydrological models, including the application of the original prediction methods under current conditions. Model simulations and sensitivity analyses indicate that a reasonable Probable Maximum Flood (PMF) at the dam site is 6311 m3/s, which is only slightly higher than the original design flood of 6000 m3/s. As part of an uncertainty assessment, the estimated PMF is sensitive to the design method, input PMP, land use changes and the floodplain inundation effect. The increase of PMP depth by 5% can cause a 7.5% increase in PMF. Deforestation by 10%, 20%, 30% can result in PMF increases of 3.1%, 6.2%, 9.2%, respectively. The modest increase of the estimated PMF (to just 6311 m3/s) in spite of these changes is due to the factoring of the hydraulic effects of trees and buildings on the floodplain as the flood situation changes from normal floods to extreme floods, when over-bank flows may be the dominant flooding process, leading to a substantial reduction in the PMF estimates.

Characterisation of flooding in Alexandria in October 2015 and suggested mitigating measures

NASA Astrophysics Data System (ADS)

Bhattacharya, Biswa; Zevenbergen, Chris; Wahaab, R. A. Wahaab R. A.; Elbarki, W. A. I. Elbarki W. A. I.; Busker, T. Busker T.; Salinas Rodriguez, C. N. A. Salinas Rodriguez C. N. A.

2017-04-01

In October 2015 Alexandria (Egypt) experienced exceptional flooding. The flooding was caused by heavy rainfall in a short period of time in a city which normally does not receive a large amount of rainfall. The heavy rainfall caused a tremendous volume of runoff, which the city's drainage system was unable to drain off to the Mediterranean Sea. Seven people have died due to the flood, and there were huge direct and indirect damages. The city does not have a flood forecasting system. An analysis with rainfall forecast from the European Centre for Medium Range Weather Forecast (ECMWF) showed that the extreme rainfall could have been forecasted about a week back. Naturally, if a flood forecasting model was in place the flooding could have been predicted well in advance. Alexandria, along with several other Arab cities, are not prepared at all for natural hazards. Preparedness actions leading to improved adaptation and resilience are not in place. The situation is being further exacerbated with rapid urbanisation and climate change. The local authorities estimate that about 30000 new buildings have been (illegally) constructed during the last five years at a location near the main pumping station (Max Point). This issue may have a very serious adverse effect on hydrology and requires further study to estimate the additional runoff from the newly urbanised areas. The World Bank has listed Alexandria as one of the five coastal cities, which may have very significant risk of coastal flooding due to the climate change. Setting up of a flood forecasting model along with an evidence-based research on the drainage system's capacity is seen as immediate actions that can significantly improve the preparedness of the city towards flooding. Furthermore, the region has got a number of large lakes, which potentially can be used to store extra water as a flood mitigation measure. Two water bodies, namely the Maryot Lake and the Airport Lake, are identified from which water can be pumped out in advance to keep storage available in case of flooding. Keywords: Alexandria, flood, Egypt, rainfall, forecasting.

46 CFR 62.35-10 - Flooding safety.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 2 2014-10-01 2014-10-01 false Flooding safety. 62.35-10 Section 62.35-10 Shipping... Requirements for Specific Types of Automated Vital Systems § 62.35-10 Flooding safety. (a) Automatic bilge.... (b) Remote controls for flooding safety equipment must remain functional under flooding conditions to...

46 CFR 62.35-10 - Flooding safety.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 2 2013-10-01 2013-10-01 false Flooding safety. 62.35-10 Section 62.35-10 Shipping... Requirements for Specific Types of Automated Vital Systems § 62.35-10 Flooding safety. (a) Automatic bilge.... (b) Remote controls for flooding safety equipment must remain functional under flooding conditions to...

46 CFR 62.35-10 - Flooding safety.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 2 2012-10-01 2012-10-01 false Flooding safety. 62.35-10 Section 62.35-10 Shipping... Requirements for Specific Types of Automated Vital Systems § 62.35-10 Flooding safety. (a) Automatic bilge.... (b) Remote controls for flooding safety equipment must remain functional under flooding conditions to...

46 CFR 62.35-10 - Flooding safety.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 2 2011-10-01 2011-10-01 false Flooding safety. 62.35-10 Section 62.35-10 Shipping... Requirements for Specific Types of Automated Vital Systems § 62.35-10 Flooding safety. (a) Automatic bilge.... (b) Remote controls for flooding safety equipment must remain functional under flooding conditions to...

Nutrient response of Bacopa monnieri (water hyssop) to varying degrees of soil saturation

USDA-ARS?s Scientific Manuscript database

Tissue concentrations of N and P were measured in Bacopa monnieri subjected to four progressive levels of flooding: well-drained Control, Intermittently Flooded, Partially Flooded, and Continuously Flooded. Soil redox potential (Eh) decreased in all flooded treatments at 30 cm depth, becoming anoxic...

46 CFR 62.35-10 - Flooding safety.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Flooding safety. 62.35-10 Section 62.35-10 Shipping... Requirements for Specific Types of Automated Vital Systems § 62.35-10 Flooding safety. (a) Automatic bilge.... (b) Remote controls for flooding safety equipment must remain functional under flooding conditions to...

Magnitude and frequency of floods in Nebraska

USGS Publications Warehouse

Beckman, Emil W.

1976-01-01

Observed maximum flood peaks at 303 gaging stations with 13 or more years of record and significant peaks at 57 short-term stations and 31 miscellaneous sites are useful in designing flood-control works for maximum safety from flood damage. Comparison is made with maximum observed floods in the United States.

33 CFR 203.47 - Modifications to non-Federal flood control works.

Code of Federal Regulations, 2010 CFR

2010-07-01

... DISASTER PROCEDURES Rehabilitation Assistance for Flood Control Works Damaged by Flood or Coastal Storm... Federal construction cost of rehabilitation to preflood level of protection, or $100,000, whichever is... only in cash. In-kind services are not permitted for modification work. (b) Protection of additional...

33 CFR 203.47 - Modifications to non-Federal flood control works.

Code of Federal Regulations, 2014 CFR

2014-07-01

... DISASTER PROCEDURES Rehabilitation Assistance for Flood Control Works Damaged by Flood or Coastal Storm... Federal construction cost of rehabilitation to preflood level of protection, or $100,000, whichever is... only in cash. In-kind services are not permitted for modification work. (b) Protection of additional...

33 CFR 203.47 - Modifications to non-Federal flood control works.

Code of Federal Regulations, 2011 CFR

2011-07-01

... DISASTER PROCEDURES Rehabilitation Assistance for Flood Control Works Damaged by Flood or Coastal Storm... Federal construction cost of rehabilitation to preflood level of protection, or $100,000, whichever is... only in cash. In-kind services are not permitted for modification work. (b) Protection of additional...

33 CFR 203.47 - Modifications to non-Federal flood control works.

Code of Federal Regulations, 2012 CFR

2012-07-01

... DISASTER PROCEDURES Rehabilitation Assistance for Flood Control Works Damaged by Flood or Coastal Storm... Federal construction cost of rehabilitation to preflood level of protection, or $100,000, whichever is... only in cash. In-kind services are not permitted for modification work. (b) Protection of additional...

33 CFR 203.47 - Modifications to non-Federal flood control works.

Code of Federal Regulations, 2013 CFR

2013-07-01

... DISASTER PROCEDURES Rehabilitation Assistance for Flood Control Works Damaged by Flood or Coastal Storm... Federal construction cost of rehabilitation to preflood level of protection, or $100,000, whichever is... only in cash. In-kind services are not permitted for modification work. (b) Protection of additional...

33 CFR 238.7 - Decision criteria for participation.

Code of Federal Regulations, 2010 CFR

2010-07-01

... larger floods, such as the one-percent flood. Examples include the presence of extremely pervious soils... control improvement. Similarly, the need to terminate flood control improvements in a safe and economical manner may justify the extension of some portions of the improvements, such as levee tiebacks, into areas...

33 CFR 238.7 - Decision criteria for participation.

Code of Federal Regulations, 2011 CFR

2011-07-01

... larger floods, such as the one-percent flood. Examples include the presence of extremely pervious soils... control improvement. Similarly, the need to terminate flood control improvements in a safe and economical manner may justify the extension of some portions of the improvements, such as levee tiebacks, into areas...

Spatial and temporal variability of water salinity in an ephemeral, arid-zone river, central Australia

NASA Astrophysics Data System (ADS)

Costelloe, Justin F.; Grayson, Rodger B.; McMahon, Thomas A.; Argent, Robert M.

2005-10-01

This study describes the spatial and temporal variability of water salinity of the Neales-Peake, an ephemeral river system in the arid Lake Eyre basin of central Australia. Saline to hypersaline waterholes occur in the lower reaches of the Neales-Peake catchment and lie downstream of subcatchments containing artesian mound springs. Flood pulses are fresh in the upper reaches of the rivers (<200 mg l-1). In the salt-affected reaches, flood pulses become increasingly saline during their recession. It is hypothesized that leakage from the Great Artesian Basin deposits salt at the surface. This salt is then transported by infrequent runoff events into the main river system over long periods of time. The bank/floodplain store downstream of salt-affected catchments contains high salt concentrations, and this salt is mobilized during the flow recession when bank/floodplain storage discharges into the channel. The salinity of the recession increases as the percentage of flow derived from this storage increases. A simple conceptual model was developed for investigating the salt movement processes during flow events. The model structure for transport of water and salt in the Neales-Peake catchment generated similar spatial and temporal patterns of salt distribution in the floodplain/bank storage and water flow as observed during flow events in 2000-02. However, more field-data collection and modelling are required for improved calibration and description of salt transport and storage processes, particularly with regard to the number of stores required to represent the salt distribution in the upper zone of the soil profile.

Integrating a reservoir regulation scheme into a spatially distributed hydrological model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, Gang; Gao, Huilin; Naz, Bibi S.

2016-12-01

During the past several decades, numerous reservoirs have been built across the world for a variety of purposes such as flood control, irrigation, municipal/industrial water supplies, and hydropower generation. Consequently, natural streamflow timing and magnitude have been altered significantly by reservoir operations. In addition, the hydrological cycle can be modified by land use/land cover and climate changes. To understand the fine scale feedback between hydrological processes and water management decisions, a distributed hydrological model embedded with a reservoir component is of desire. In this study, a multi-purpose reservoir module with predefined complex operational rules was integrated into the Distributed Hydrologymore » Soil Vegetation Model (DHSVM). Conditional operating rules, which are designed to reduce flood risk and enhance water supply reliability, were adopted in this module. The performance of the integrated model was tested over the upper Brazos River Basin in Texas, where two U.S. Army Corps of Engineers reservoirs, Lake Whitney and Aquilla Lake, are located. The integrated DHSVM model was calibrated and validated using observed reservoir inflow, outflow, and storage data. The error statistics were summarized for both reservoirs on a daily, weekly, and monthly basis. Using the weekly reservoir storage for Lake Whitney as an example, the coefficients of determination (R2) and the Nash-Sutcliff Efficiency (NSE) are 0.85 and 0.75, respectively. These results suggest that this reservoir module has promise for use in sub-monthly hydrological simulations. Enabled with the new reservoir component, the DHSVM model provides a platform to support adaptive water resources management under the impacts of evolving anthropogenic activities and substantial environmental changes.« less

Synergizing green and gray infrastructures to increase water supply resilience in the Brazos River basin in Texas

NASA Astrophysics Data System (ADS)

Gao, H.; Yamazaki, D.; Finley, T.; Bohn, T. J.; Low, G.; Sabo, J. L.

2017-12-01

Water infrastructure lies at the heart of the challenges and opportunities of Integrated Water Resource Management (IWRM). Green infrastructure (e.g., wetlands restoration) presents an alternative to its hard-path counterpart - gray infrastructure, which often has external, economic and unmeasured ecological costs. But the science framework to prioritize green infrastructure buildout is nascent. In this study, we addressed this gap in Brazos River basin in Texas, in the context of corporate decisions to secure water supplies for various water stewardship objectives. We developed a physically-based tool to quantify the potential for wetland restoration to restore desired flows (hydrology), and a financial framework for comparing its cost-benefit with heightening an existing dam (conservation finance). Our framework has three components. First, we harnessed a topographic index (HAND) to identify the potential wetlands sites. Second, we coupled a land surface model (VIC) with a hydrodynamic model (CaMa-Flood) to investigate the effects of wetland size, location, and vegetation on hydrology. Finally, we estimated the net present value, indirect rate of return and payback period for green (wetlands) vs. gray (reservoir expansion) infrastructure. We found wetlands have more substantial impact on peak flow than baseflow. Interestingly, wetlands can improve baseflow reliability but not directly except with the largest (>400 km2) projects. Peak flow reduction volumes of wetlands if used as credits towards reservoir flood-control storage provide adequate conservation storage to deliver guaranteed reliability of baseflow. Hence, the synergy of existing dams with newly created wetlands offers a promising natural solution to increase water supply resilience, while green projects also generate revenue compared to their gray counterparts. This study demonstrates the possibility of using innovative engineering design to synergize green and gray infrastructures to convert water conflict to opportunities.

Classification and assessment of water bodies as adaptive structural measures for flood risk management planning.

PubMed

McMinn, William R; Yang, Qinli; Scholz, Miklas

2010-09-01

Severe rainfall events have become increasingly common in Europe. Flood defence engineering works are highly capital intensive and can be limited by land availability, leaving land and communities exposed to repeated flooding. Any adaptive drainage structure must have engineered inlets and outlets that control the water level and the rate of release. In Scotland, there are a relatively high number of drinking water reservoirs (operated by Scottish Water), which fall within this defined category and could contribute to flood management control. Reducing the rate of runoff from the upper reaches of a catchment will reduce the volume and peak flows of flood events downstream, thus allowing flood defences to be reduced in size, decreasing the corresponding capital costs. A database of retention basins with flood control potential has been developed for Scotland. The research shows that the majority of small and former drinking water reservoirs are kept full and their spillways are continuously in operation. Utilising some of the available capacity to contribute to flood control could reduce the costs of complying with the EU Flood Directive. Furthermore, the application of a previously developed classification model for Baden in Germany for the Scottish data set showed a lower diversity for basins in Scotland due to less developed infrastructure. The principle value of this approach is a clear and unambiguous categorisation, based on standard variables, which can help to promote communication and understanding between stakeholders. 2010 Elsevier Ltd. All rights reserved.

Storage and remobilization of suspended sediment in the lower amazon river of Brazil

USGS Publications Warehouse

Meade, R.H.; Dunne, T.; Richey, J.E.; Santos, U.De. M.; Salati, E.

1985-01-01

In the lower Amazon River, suspended sediment is stored during rising stages of the river and resuspended during falling river stages. The storage and resuspension in the reach are related to the mean slope of the flood wave on the river surface; this slope is smaller during rising river stages than during falling stages. The pattern of storage and resuspension damps out the extreme values of high and low sediment discharge and tends to keep them near the mean value between 3.0 ?? 106 and 3.5 ?? 106 metric tons per day. Mean annual discharge of suspended sediment in the lower Amazon is between 1.1 ?? 109 and 1.3 ?? 109 metric tons per year.

Mental health impacts of flooding: a controlled interrupted time series analysis of prescribing data in England

PubMed Central

Milojevic, Ai; Armstrong, Ben; Wilkinson, Paul

2017-01-01

Background There is emerging evidence that people affected by flooding suffer adverse impacts on their mental well-being, mostly based on self-reports. Methods We examined prescription records for drugs used in the management of common mental disorder among primary care practices located in the vicinity of recent large flood events in England, 2011–2014. A controlled interrupted time series analysis was conducted of the number of prescribing items for antidepressant drugs in the year before and after the flood onset. Pre–post changes were compared by distance of the practice from the inundated boundaries among 930 practices located within 10 km of a flood. Results After control for deprivation and population density, there was an increase of 0.59% (95% CI 0.24 to 0.94) prescriptions in the postflood year among practices located within 1 km of a flood over and above the change observed in the furthest distance band. The increase was greater in more deprived areas. Conclusions This study suggests an increase in prescribed antidepressant drugs in the year after flooding in primary care practices close to recent major floods in England. The degree to which the increase is actually concentrated in those flooded can only be determined by more detailed linkage studies. PMID:28860201

Floods of June 1965 in South Platte River basin, Colorado

USGS Publications Warehouse

Matthai, Howard Frederick

1969-01-01

Heavy, intense rains in three areas on three different days caused outstanding floods on many streams in the South Platte River basin from Plum Creek, just south of Denver, downstream to the Colorado-Nebraska State line. The flood-producing storms followed a relatively wet period, and rainfall of as much as 14 inches in a few hours was reported. The storms occurred over the Greeley-Sterling area on June 14-15, over the Plum Creek and Cherry Creek basins on June 16, and over the headwaters of Kiowa and Bijou Creeks on June 17 after heavy rains on June 15. The flood crest did not pass Julesburg, in the northeast corner of Colorado, until June 20. Previous record high discharges on many tributaries with drainage areas on the plains were exceeded, sometimes severalfold. The six principal tributaries carrying snowmelt runoff were contributing, but not significant, factors in the floods. The attenuation of the peak flow by channel storage as the flood passed through Denver was considerable; yet the peak discharge of 40,300 cfs (cubic feet per second) of the South Platte River at Denver was 1.8 times the previously recorded high of 22,000 cfs in a period of record starting in 1889. The 1965 peak would have been still higher except that all flow from Cherry Creek was stored in Cherry Creek Reservoir. Six persons were drowned, and two other deaths were attributed to the storms. The total damage amounted to $508.2 million, and about 75 percent of this occurred in the Denver metropolitan area. Descriptions of the storms and floods, detailed streamflow records, and information on damages, flood profiles, inundated areas, and flood frequency are included in this report. Several comparisons of the magnitude of the flood are made, and all indicate that an outstanding hydrologic event occurred.

Impact of the Three-Gorges Dam and water transfer project on Changjiang floods

NASA Astrophysics Data System (ADS)

Nakayama, Tadanobu; Shankman, David

2013-01-01

Increasing frequency of severe floods on the middle and lower Changjiang (Yangtze) River during the past few decades can be attributed to both abnormal monsoon rainfall and landscape changes that include extensive deforestation affecting river sedimentation, and shrinking lakes and levee construction that reduced the areas available for floodwater storage. The Three-Gorges Dam (TGD) and the South-to-North Water Transfer Project (SNWTP) will also affect frequency and intensity of severe floods in the Poyang Lake region of the middle Changjiang. Process-based National Integrated Catchment-based Eco-hydrology (NICE) model predicts that the TGD will increase flood risk during the early summer monsoon against the original justifications for building the dam, relating to complex river-lake-groundwater interactions. Several scenarios predict that morphological change will increase flood risk around the lake. This indicates the importance of managing both flood discharge and sediment deposition for the entire basin. Further, the authors assessed the impact of sand mining in the lake after its prohibition on the Changjiang, and clarified that alternative scenario of sand mining in lakes currently disconnected from the mainstream would reduce the flood risk to a greater extent than intensive dredging along junction channel. Because dry biomasses simulated by the model were linearly related to the Time-Integrated Normalized Difference Vegetation Index (TINDVI) estimated from satellite images, its decadal gradient during 1982-1999 showed a spatially heterogeneous distribution and generally decreasing trends beside the lakes, indicating that the increases in lake reclamation and the resultant decrease in rice productivity are closely related to the hydrologic changes. This integrated approach could help to minimize flood damage and promote better decisions addressing sustainable development.

The effects of low impact development on urban flooding under different rainfall characteristics.

PubMed

Qin, Hua-peng; Li, Zhuo-xi; Fu, Guangtao

2013-11-15

Low impact development (LID) is generally regarded as a more sustainable solution for urban stormwater management than conventional urban drainage systems. However, its effects on urban flooding at a scale of urban drainage systems have not been fully understood particularly when different rainfall characteristics are considered. In this paper, using an urbanizing catchment in China as a case study, the effects of three LID techniques (swale, permeable pavement and green roof) on urban flooding are analyzed and compared with the conventional drainage system design. A range of storm events with different rainfall amounts, durations and locations of peak intensity are considered for holistic assessment of the LID techniques. The effects are measured by the total flood volume reduction during a storm event compared to the conventional drainage system design. The results obtained indicate that all three LID scenarios are more effective in flood reduction during heavier and shorter storm events. Their performance, however, varies significantly according to the location of peak intensity. That is, swales perform best during a storm event with an early peak, permeable pavements perform best with a middle peak, and green roofs perform best with a late peak, respectively. The trends of flood reduction can be explained using a newly proposed water balance method, i.e., by comparing the effective storage depth of the LID designs with the accumulative rainfall amounts at the beginning and end of flooding in the conventional drainage system. This paper provides an insight into the performance of LID designs under different rainfall characteristics, which is essential for effective urban flood management. Copyright © 2013 Elsevier Ltd. All rights reserved.

Rainfall Threshold for Flash Flood Early Warning Based on Rational Equation: A Case Study of Zuojiao Watershed in Yunnan Province

NASA Astrophysics Data System (ADS)

Li, Q.; Wang, Y. L.; Li, H. C.; Zhang, M.; Li, C. Z.; Chen, X.

2017-12-01

Rainfall threshold plays an important role in flash flood warning. A simple and easy method, using Rational Equation to calculate rainfall threshold, was proposed in this study. The critical rainfall equation was deduced from the Rational Equation. On the basis of the Manning equation and the results of Chinese Flash Flood Survey and Evaluation (CFFSE) Project, the critical flow was obtained, and the net rainfall was calculated. Three aspects of the rainfall losses, i.e. depression storage, vegetation interception, and soil infiltration were considered. The critical rainfall was the sum of the net rainfall and the rainfall losses. Rainfall threshold was estimated after considering the watershed soil moisture using the critical rainfall. In order to demonstrate this method, Zuojiao watershed in Yunnan Province was chosen as study area. The results showed the rainfall thresholds calculated by the Rational Equation method were approximated to the rainfall thresholds obtained from CFFSE, and were in accordance with the observed rainfall during flash flood events. Thus the calculated results are reasonable and the method is effective. This study provided a quick and convenient way to calculated rainfall threshold of flash flood warning for the grass root staffs and offered technical support for estimating rainfall threshold.

Hydrologic effects of hypothetical earthquake-caused floods below Jackson Lake, northwestern Wyoming

USGS Publications Warehouse

Glass, W.R.; Keefer, T.N.; Rankl, J.G.

1976-01-01

Jackson Lake, located in Grand Teton National Park, Wyoming, is in an area of seismic instability. There is a possibility of flooding in the Snake River downstream from Jackson Lake Dam in the event of a severe earthquake. Hypothetical floods were routed 38 miles (61 kilometers) downstream from the dam for three cases: (1) Instantaneous destruction of the dam outlet structure, (2) instantaneous destruction of the entire dam, and (3) for waves overtopping the dam without failure of the dam. In each case, a full reservoir was assumed. Hydrographs for outflow from the reservoir for the two cases of dam failure were developed utilizing an accelerated discharge due to the travel of a negative wave through the reservoir, and Muskingum storage routing. For the case of waves overtopping the dam, a 10-foot (3-meter) wave was assumed to be propagated from the upstream end of the reservori. A multiple-linearization technique was used to route the flow through the reach. The model was calibrated from U.S. Geological Survey streamflow records. Most extensive flooding and largest water velocities would occur if the entire dam were destroyed; floods for the other two cases were smaller. An inundation map was prepared from channel conveyance curves and profiles of the water surface. (Woodard-USGS)

Effect of reservoir storage on peak flow

USGS Publications Warehouse

Mitchell, William D.

1962-01-01

For observation of small-basin flood peaks, numerous crest-stage gages now are operated at culverts in roadway embankments. To the extent that they obstruct the natural flood plains of the streams, these embankments serve to create detention reservoirs, and thus to reduce the magnitude of observed peak flows. Hence, it is desirable to obtain a factor, I/O, by which the observed outflow peaks may be adjusted to corresponding inflow peaks. The problem is made more difficult by the fact that, at most of these observation sites, only peak stages and discharges are observed, and complete hydrographs are not available. It is postulated that the inflow hydrographs may be described in terms of Q, the instantaneous discharge; A, the size of drainage area; Pe, the amount of rainfall excess; H, the time from beginning of rainfall excess; D, the duration of rainfall excess; and T and k, characteristic times for the drainage area, and indicative of the time lag between rainfall and runoff. These factors are combined into the dimensionless ratios (QT/APe), (H/T), (k/T), and (D/T), leading to families of inflow hydrographs in which the first ratio is the ordinate, the second is the abscissa, and the third and fourth are distinguishing parameters. Sixteen dimensionless inflow hydrographs have been routed through reservoir storage to obtain 139 corresponding outflow hydrographs. In most of the routings it has been assumed that the storage-outflow relation is linear; that is, that storage is some constant, K, times the outflow. The existence of nonlinear storage is recognized, and exploratory nonlinear routings are described, but analyses and conclusions are confined to the problems of linear storage. Comparisons between inflow hydrographs and outflow hydrographs indicate that, at least for linear storage, I/O=f(k/T, D/T, K/T) in which I and O are, respectively, the magnitudes of the inflow and the outflow peaks, and T, k, D, and K are as defined above. Diagrams are presented to show the functional relation indicated by the foregoing equation.

Looking for Similarities Between Lowland (Flash) Floods

NASA Astrophysics Data System (ADS)

Brauer, C.; Teuling, R.; Torfs, P.; Hobbelt, L.; Jansen, F.; Melsen, L.; Uijlenhoet, R.

2012-12-01

On 26 August 2010 the eastern part of The Netherlands and the bordering part of Germany were struck by a series of rainfall events. Over an area of 740 km2 more than 120 mm of rainfall were observed in 24 h. We investigated the unprecedented flash flood triggered by this exceptionally heavy rainfall event (return period > 1000 years) in the 6.5 km2 Hupsel Brook catchment, which has been the experimental watershed employed by Wageningen University since the 1960s. This study improved our understanding of the dynamics of such lowland flash floods (Brauer et al., 2011). These observations, however, only show how our experimental catchment behaved and the results cannot be extrapolated directly to different floods in other (neighboring) lowland catchments. Therefore, it is necessary to use the information collected in one well-monitored catchment in combination with data from other, less well monitored catchments to find common signatures which could describe the runoff response during a lowland flood as a function of catchment characteristics. Because of the large spatial extent of the rainfall event in August 2010, many brooks and rivers in the Netherlands and Germany flooded. With data from several catchments we investigated the influence of rainfall and catchment characteristics (such as slope, size and land use) on the reaction of discharge to rainfall. We also investigated the runoff response in these catchments during previous floods by analyzing the relation between storage and discharge and the recession curve. In addition to the flood in August 2010, two other floods occurred in The Netherlands in recently. The three floods occurred in different parts of the country, after different types of rainfall events and with different initial conditions. We selected several catchments during each flood to compare their response and find out if these cases are fundamentally different or that they were produced by the same underlying processes and can be treated in a similar manner. Brauer, C. C., Teuling, A.J., Overeem, A., van der Velde, Y., Hazenberg, P., Warmerdam, P. M. M. and Uijlenhoet, R.: Anatomy of extraordinary rainfall and flash flood in a Dutch lowland catchment, Hydrol. Earth Syst. Sci., 15, 1991-2005, 2011.

43 CFR 418.24 - Precautionary drawdown and spills from Lahontan Reservoir.

Code of Federal Regulations, 2012 CFR

2012-10-01

..., precautionary drawdown of Lahontan Reservoir may be made to limit potential flood damage along the Carson River... will be determined by comparison with other years' data and normalized by comparison of differences in... objective in subsequent months will be reduced by one-half of the difference between that month's storage...

43 CFR 418.24 - Precautionary drawdown and spills from Lahontan Reservoir.

Code of Federal Regulations, 2014 CFR

2014-10-01

..., precautionary drawdown of Lahontan Reservoir may be made to limit potential flood damage along the Carson River... will be determined by comparison with other years' data and normalized by comparison of differences in... objective in subsequent months will be reduced by one-half of the difference between that month's storage...

43 CFR 418.24 - Precautionary drawdown and spills from Lahontan Reservoir.

Code of Federal Regulations, 2013 CFR

2013-10-01

..., precautionary drawdown of Lahontan Reservoir may be made to limit potential flood damage along the Carson River... will be determined by comparison with other years' data and normalized by comparison of differences in... objective in subsequent months will be reduced by one-half of the difference between that month's storage...

Postfire rehabilitation treatments: are we learning what works?

Treesearch

P. R. Robichaud; R. E. Brown

2005-01-01

Major concerns after wildfires are the increased erosion and flooding potential due to loss of the protective forest floor layer, loss of water storage, and the creation of water repellent soil conditions. Treatments to mitigate postfire erosion and runoff are commonly applied on highly erodible areas; however the effectiveness of these treatments has had limited...

Long-term effects of wetland harvesting practices on productivity and carbon pools

Treesearch

Scott McKee; Mike Aust; John Seiler; Brian Strahm

2012-01-01

Forested wetlands are valued for social and ecological benefits including filtering sediments, uptake of nutrients, carbon storage, reduction of flood depths, protection of shorelines and streambanks, and provision of terrestrial and aquatic wildlife habitat (Walbridge 1993, Kellison and Young 1997, Brady and Weil 2002). Although the importance of wetland functions are...

Laboratory testing of the (Japan Storage Battery) traction batteries GS E75A and GS E150H

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

This report describes the testing of the GS E75A and GS E150H flooded lead-acid 12-volt traction batteries and compares the selected batteries to U.S.-made electric vehicle batteries. The results and conclusions of the testing are presented.

Life cycle of soil sggregates: from root residue to microbial and physical hotspots

NASA Astrophysics Data System (ADS)

Ghezzehei, T. A.; Or, D.

2017-12-01

Soil aggregation is a physical state of soil in which clumps of primary soil particles are held together by biological and/or chemical cementing agents. Aggregations plays important role in storage and movement of water and essential gases, nutrient cycling, and ultimately supporting microbial and plant life. It is also one of the most dynamic and sensitive soil qualities, which readily responds to disturbances such as cultivation, fire, drought, flooding, and changes in vegetation. Soil aggregation that is primarily controlled by organic matter generally exhibits hierarchical organization of soil constituents into stable units that range in size from a few microns to centimeters. However, this conceptual model of soil aggregation as the key unifying mechanism remains poorly quantified and is rarely included in predictive soil models. Here we provide a biophysical framework for quantitative and predictive modeling of soil aggregation and its attendant soil characteristics. The framework treats aggregates as hotspots of biological, chemical and physical processes centered around roots and root residue. We keep track of the life cycle of an individual aggregate from it genesis in the rhizosphere, fueled by rhizodeposition and mediated by vigorous microbial activity, until its disappearance when the root-derived resources are depleted. The framework synthesizes current understanding of microbial life in porous media; water holding and soil binding capacity of biopolymers; and environmental controls on soil organic matter dynamics. The framework paves a way for integration of processes that are presently modeled as disparate or poorly coupled processes, including storage and protection of carbon, microbial activity, greenhouse gas fluxes, movement and storage of water, resistance of soils against erosion.

Quality control of the RMS US flood model

NASA Astrophysics Data System (ADS)

Jankowfsky, Sonja; Hilberts, Arno; Mortgat, Chris; Li, Shuangcai; Rafique, Farhat; Rajesh, Edida; Xu, Na; Mei, Yi; Tillmanns, Stephan; Yang, Yang; Tian, Ye; Mathur, Prince; Kulkarni, Anand; Kumaresh, Bharadwaj Anna; Chaudhuri, Chiranjib; Saini, Vishal

2016-04-01

The RMS US flood model predicts the flood risk in the US with a 30 m resolution for different return periods. The model is designed for the insurance industry to estimate the cost of flood risk for a given location. Different statistical, hydrological and hydraulic models are combined to develop the flood maps for different return periods. A rainfall-runoff and routing model, calibrated with observed discharge data, is run with 10 000 years of stochastic simulated precipitation to create time series of discharge and surface runoff. The 100, 250 and 500 year events are extracted from these time series as forcing for a two-dimensional pluvial and fluvial inundation model. The coupling of all the different models which are run on the large area of the US implies a certain amount of uncertainty. Therefore, special attention is paid to the final quality control of the flood maps. First of all, a thorough quality analysis of the Digital Terrain model and the river network was done, as the final quality of the flood maps depends heavily on the DTM quality. Secondly, the simulated 100 year discharge in the major river network (600 000 km) is compared to the 100 year discharge derived using extreme value distribution of all USGS gauges with more than 20 years of peak values (around 11 000 gauges). Thirdly, for each gauge the modelled flood depth is compared to the depth derived from the USGS rating curves. Fourthly, the modelled flood depth is compared to the base flood elevation given in the FEMA flood maps. Fifthly, the flood extent is compared to the FEMA flood extent. Then, for historic events we compare flood extents and flood depths at given locations. Finally, all the data and spatial layers are uploaded on geoserver to facilitate the manual investigation of outliers. The feedback from the quality control is used to improve the model and estimate its uncertainty.

Improving Flood Risk Management for California's Central Valley: How the State Developed a Toolbox for Large, System-wide Studies

NASA Astrophysics Data System (ADS)

Pingel, N.; Liang, Y.; Bindra, A.

2016-12-01

More than 1 million Californians live and work in the floodplains of the Sacramento-San Joaquin Valley where flood risks are among the highest in the nation. In response to this threat to people, property and the environment, the Department of Water Resources (DWR) has been called to action to improve flood risk management. This has transpired through significant advances in development of flood information and tools, analysis, and planning. Senate Bill 5 directed DWR to prepare the Central Valley Flood Protection Plan (CVFPP) and update it every 5 years. A key component of this aggressive planning approach is answering the question: What is the current flood risk, and how would proposed improvements change flood risk throughout the system? Answering this question is a substantial challenge due to the size and complexity of the watershed and flood control system. The watershed is roughly 42,000 sq mi, and flows are controlled by numerous reservoirs, bypasses, and levees. To overcome this challenge, the State invested in development of a comprehensive analysis "tool box" through various DWR programs. Development of the tool box included: collection of hydro-meteorological, topographic, geotechnical, and economic data; development of rainfall-runoff, reservoir operation, hydraulic routing, and flood risk analysis models; and development of specialized applications and computing schemes to accelerate the analysis. With this toolbox, DWR is analyzing flood hazard, flood control system performance, exposure and vulnerability of people and property to flooding, consequence of flooding for specific events, and finally flood risk for a range of CVFPP alternatives. Based on the results, DWR will put forward a State Recommended Plan in the 2017 CVFPP. Further, the value of the analysis tool box extends beyond the CVFPP. It will serve as a foundation for other flood studies for years to come and has already been successfully applied for inundation mapping to support emergency response, reservoir operation analysis, and others.

Impact of fresh and saline water flooding on leaf gas exchange in two Italian provenances of Tamarix africana Poiret.

PubMed

Abou Jaoudé, R; de Dato, G; Palmegiani, M; De Angelis, P

2013-01-01

In Mediterranean coastal areas, changes in precipitation patterns and seawater levels are leading to increased frequency of flooding and to salinization of estuaries and freshwater systems. Tamarix spp. are often the only woody species growing in such environments. These species are known for their tolerance to moderate salinity; however, contrasting information exists regarding their tolerance to flooding, and the combination of the two stresses has never been studied in Tamarix spp. Here, we analyse the photosynthetic responses of T. africana Poiret to temporary flooding (45 days) with fresh or saline water (200 mm) in two Italian provenances (Simeto and Baratz). The measurements were conducted before and after the onset of flooding, to test the possible cumulative effects of the treatments and effects on twig aging, and to analyse the responses of twigs formed during the experimental period. Full tolerance was evident in T. africana with respect to flooding with fresh water, which did not affect photosynthetic performances in either provenance. Saline flooding was differently tolerated by the two provenances. Moreover, salinity tolerance differently affected the two twig generations. In particular, a reduction in net assimilation rate (-48.8%) was only observed in Baratz twigs formed during the experimental period, compared to pre-existing twigs. This reduction was a consequence of non-stomatal limitations (maximum carboxylation rate and electron transport), probably as a result of higher Na transport to the twigs, coupled with reduced Na storage in the roots. © 2012 German Botanical Society and The Royal Botanical Society of the Netherlands.

78 FR 75370 - Draft Supplemental Environmental Assessment and Finding of No Significant Impact for Flood...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-11

... Environmental Assessment and Finding of No Significant Impact for Flood Control Improvements to the Rio Grande... Supplemental Environmental Assessment (SEA) and Finding of No Significant Impact (FONSI). SUMMARY: Pursuant to... Significant Impact for Flood Control Improvements to the Rio Grande Canalization Project in Vado, New Mexico...

Resesrvoir sedimentation rates in the Little Washita River experimental watershed, Oklahoma

USDA-ARS?s Scientific Manuscript database

The Washita River Basin (WRB) was one of eleven pilot watershed projects selected for construction of flood control reservoirs around the country as a result of the Flood Control Act of 1936. These reservoirs were implemented to prevent and manage soil erosion and flooding. A total of 45 reservoirs ...

A novel algorithm for monitoring reservoirs under all-weather conditions at a high temporal resolution through passive microwave remote sensing

NASA Astrophysics Data System (ADS)

Zhang, Shuai; Gao, Huilin

2016-08-01

Flood mitigation in developing countries has been hindered by a lack of near real-time reservoir storage information at high temporal resolution. By leveraging satellite passive microwave observations over a reservoir and its vicinity, we present a globally applicable new algorithm to estimate reservoir storage under all-weather conditions at a 4 day time step. A weighted horizontal ratio (WHR) based on the brightness temperatures at 36.5 GHz is introduced, with its coefficients calibrated against an area training data set over each reservoir. Using a predetermined area-elevation (A-H) relationship, these coefficients are then applied to the microwave data to calculate the storage. Validation results over four reservoirs in South Asia indicate that the microwave-based storage estimations (after noise reduction) perform well (with coefficients of determination ranging from 0.41 to 0.74). This is the first time that passive microwave observations are fused with other satellite data for quantifying the storage of individual reservoirs.

A technique for estimating time of concentration and storage coefficient values for Illinois streams

USGS Publications Warehouse

Graf, Julia B.; Garklavs, George; Oberg, Kevin A.

1982-01-01

Values of the unit hydrograph parameters time of concentration (TC) and storage coefficient (R) can be estimated for streams in Illinois by a two-step technique developed from data for 98 gaged basins in the State. The sum of TC and R is related to stream length (L) and main channel slope (S) by the relation (TC + R)e = 35.2L0.39S-0.78. The variable R/(TC + R) is not significantly correlated with drainage area, slope, or length, but does exhibit a regional trend. Regional values of R/(TC + R) are used with the computed values of (TC + R)e to solve for estimated values of time of concentration (TCe) and storage coefficient (Re). The use of the variable R/(TC + R) is thought to account for variations in unit hydrograph parameters caused by physiographic variables such as basin topography, flood-plain development, and basin storage characteristics. (USGS)

New version of 1 km global river flood hazard maps for the next generation of Aqueduct Global Flood Analyzer

NASA Astrophysics Data System (ADS)

Sutanudjaja, Edwin; van Beek, Rens; Winsemius, Hessel; Ward, Philip; Bierkens, Marc

2017-04-01

The Aqueduct Global Flood Analyzer, launched in 2015, is an open-access and free-of-charge web-based interactive platform which assesses and visualises current and future projections of river flood impacts across the globe. One of the key components in the Analyzer is a set of river flood inundation hazard maps derived from the global hydrological model simulation of PCR-GLOBWB. For the current version of the Analyzer, accessible on http://floods.wri.org/#/, the early generation of PCR-GLOBWB 1.0 was used and simulated at 30 arc-minute ( 50 km at the equator) resolution. In this presentation, we will show the new version of these hazard maps. This new version is based on the latest version of PCR-GLOBWB 2.0 (https://github.com/UU-Hydro/PCR-GLOBWB_model, Sutanudjaja et al., 2016, doi:10.5281/zenodo.60764) simulated at 5 arc-minute ( 10 km at the equator) resolution. The model simulates daily hydrological and water resource fluxes and storages, including the simulation of overbank volume that ends up on the floodplain (if flooding occurs). The simulation was performed for the present day situation (from 1960) and future climate projections (until 2099) using the climate forcing created in the ISI-MIP project. From the simulated flood inundation volume time series, we then extract annual maxima for each cell, and fit these maxima to a Gumbel extreme value distribution. This allows us to derive flood volume maps of any hazard magnitude (ranging from 2-year to 1000-year flood events) and for any time period (e.g. 1960-1999, 2010-2049, 2030-2069, and 2060-2099). The derived flood volumes (at 5 arc-minute resolution) are then spread over the high resolution terrain model using an updated GLOFRIS downscaling module (Winsemius et al., 2013, doi:10.5194/hess-17-1871-2013). The updated version performs a volume spreading sequentially from more upstream basins to downstream basins, hence enabling a better inclusion of smaller streams, and takes into account spreading of water over diverging deltaic regions. This results in a set of high resolution hazard maps of flood inundation depth at 30 arc-second ( 1 km at the equator) resolution. Together with many other updates and new features, the resulting flood hazard maps will be used in the next generation of the Aqueduct Global Flood Analyzer.

Temporal and spatial patterns of sedimentation within the batture lands of the middle Mississippi River, USA

NASA Astrophysics Data System (ADS)

Remo, Jonathan W. F.; Ryherd, Julia; Ruffner, Charles M.; Therrell, Matthew D.

2018-05-01

Sediment deposition and storage are important functions of batture lands (the land between the channel's low-water elevation and the flood mitigation levee). However, sedimentation processes within these areas are not fully understood. In this paper, we explore the spatiotemporal patterns, rates, and volume of sedimentation within the batture lands along the middle Mississippi River (MMR; between the confluence of the Missouri and Ohio rivers) using three approaches: (1) comparison of historical to modern elevation data in order to estimate long-term (>100 yr) sedimentation rates; (2) estimation of medium- to short-term (<50 yr) sedimentation rates using dendrogeomorphological methods; and (3) geomorphic change detection (GCD) software to estimate short-term sedimentation rates ( 12 yr), spatial patterns of deposition, and volumes of geomorphic change within the batture lands. Comparison of long- to short-term sedimentation rates suggests up to a 300% increase in batture land sedimentation rates (from 6.2 to 25.4 mm yr-1) despite a substantial decrease in the MMR's suspended-sediment load (>70%) attributed largely to sediment trapping by dams during the second half of the twentieth century. The increase in MMR batture land sedimentation rates are attributed to at least two potential mechanisms: (1) the above average frequency and duration of low-magnitude floods (>2-yr and ≤5-yr flood) during the short-term assessment periods which allowed for more suspended sediment to be deposited within the batture lands; and (2) the construction of levees that substantially reduced the floodplain area ( 75%) available for storage of overbank deposits increasing the vertical accumulation and consequently the detectability of a given volume of sediment. The GCD estimated batture land sediment volumes were 9.0% of the suspended load at St. Louis. This substantial storage of sediment ( 8.5 Mt yr-1) along the MMR suggests batture lands are an important sink for suspended sediments.

Future irrigation expansion outweigh groundwater recharge gains from climate change in semi-arid India.

PubMed

Sishodia, Rajendra P; Shukla, Sanjay; Wani, Suhas P; Graham, Wendy D; Jones, James W

2018-09-01

Simultaneous effects of future climate and irrigation intensification on surface and groundwater systems are not well understood. Efforts are needed to understand the future groundwater availability and associated surface flows under business-as-usual management to formulate policy changes to improve water sustainability. We combine measurements with integrated modeling (MIKE SHE/MIKE11) to evaluate the effects of future climate (2040-2069), with and without irrigation expansion, on water levels and flows in an agricultural watershed in low-storage crystalline aquifer region of south India. Demand and supply management changes, including improved efficiency of irrigation water as well as energy uses, were evaluated. Increased future rainfall (7-43%, from 5 Global Climate Models) with no further expansion of irrigation wells increased the groundwater recharge (10-55%); however, most of the recharge moved out of watershed as increased baseflow (17-154%) with a small increase in net recharge (+0.2mm/year). When increased rainfall was considered with projected increase in irrigation withdrawals, both hydrologic extremes of well drying and flooding were predicted. A 100-year flow event was predicted to be a 5-year event in the future. If irrigation expansion follows the historical trends, earlier and more frequent well drying, a source of farmers' distress in India, was predicted to worsen in the future despite the recharge gains from increased rainfall. Storage and use of excess flows, improved irrigation efficiency with flood to drip conversion in 25% of irrigated area, and reduced energy subsidy (free electricity for 3.5h compared to 7h/day; $1 billion savings) provided sufficient water savings to support future expansion in irrigated areas while mitigating well drying as well as flooding. Reductions in energy subsidy to fund the implementation of economically desirable (high benefit-cost ratio) demand (drip irrigation) and supply (water capture and storage) management was recommended to achieve a sustainable food-water-energy nexus in semi-arid regions. Copyright © 2018 Elsevier B.V. All rights reserved.

Enhancing drought resilience with conjunctive use and managed aquifer recharge in California and Arizona

NASA Astrophysics Data System (ADS)

Scanlon, Bridget R.; Reedy, Robert C.; Faunt, Claudia C.; Pool, Donald; Uhlman, Kristine

2016-03-01

Projected longer-term droughts and intense floods underscore the need to store more water to manage climate extremes. Here we show how depleted aquifers have been used to store water by substituting surface water use for groundwater pumpage (conjunctive use, CU) or recharging groundwater with surface water (managed aquifer recharge, MAR). Unique multi-decadal monitoring from thousands of wells and regional modeling datasets for the California Central Valley and central Arizona were used to assess CU and MAR. In addition to natural reservoir capacity related to deep water tables, historical groundwater depletion further expanded aquifer storage by ˜44 km3 in the Central Valley and by ˜100 km3 in Arizona, similar to or exceeding current surface reservoir capacity by up to three times. Local river water and imported surface water, transported through 100s of km of canals, is substituted for groundwater (≤15 km3 yr-1, CU) or is used to recharge groundwater (MAR, ≤1.5 km3 yr-1) during wet years shifting to mostly groundwater pumpage during droughts. In the Central Valley, CU and MAR locally reversed historically declining water-level trends, which contrasts with simulated net regional groundwater depletion. In Arizona, CU and MAR also reversed historically declining groundwater level trends in active management areas. These rising trends contrast with current declining trends in irrigated areas that lack access to surface water to support CU or MAR. Use of depleted aquifers as reservoirs could expand with winter flood irrigation or capturing flood discharges to the Pacific (0-1.6 km3 yr-1, 2000-2014) with additional infrastructure in California. Because flexibility and expanded portfolio options translate to resilience, CU and MAR enhance drought resilience through multi-year storage, complementing shorter term surface reservoir storage, and facilitating water markets.

Can erosion control structures in large dryland arroyo channels lead to resilient riparian and cienega restoration? Observations from LiDAR, monitoring and modeling at Rancho San Bernardino, Sonora, MX

NASA Astrophysics Data System (ADS)

DeLong, S.; Henderson, W. M.

2012-12-01

The use of erosion control structures to mitigate or even reverse erosion and to restore ecological function along dryland channels (arroyos and gullies) has led to a long list of both successful and failed restoration efforts. We propose that successful implementation of "engineering" approaches to fluvial restoration that include in-channel control structures require either a quantitative approach to design (by scientists and engineers), or intimate on-the-ground knowledge, local observation, and a commitment to adapt and maintain restoration efforts in response to landscape change (by local land managers), or both. We further propose that the biophysical interactions among engineering, sedimentation, flood hydrology and vegetation reestablishment are what determine resilience to destructive extreme events that commonly cause erosion control structure failure. Our insights come from comprehensive monitoring of a remarkable experiment underway at Ranch San Bernardino, Sonora, MX. At this site, private landowners are working to restore ecosystem function to riparian corridors and former cieñega wetlands using cessation of grazing; vegetation planting; upland grass restoration; large scale rock gabions (up to 100 m wide) to encourage local sediment deposition and water storage; and large earthen berms (up to 900 m wide) with cement spillways that form reservoirs that fill rapidly with water and sediment. Well-planned and managed erosion control structures have been used elsewhere successfully in smaller gully networks, but we are unaware of a comparable attempt to use gabions and berms for the sole purpose of ecological restoration along >10 km of arroyo channels draining watersheds on the order of ~400 km2 and larger. We present an approach to monitoring the efficacy of arroyo channel restoration using terrestrial and airborne LiDAR, remote sensing, streamflow monitoring, shallow groundwater monitoring, hydrological modeling and field observation. Our methods allow us to directly quantify the magnitude of sedimentation (and hence reversal of arroyo cutting) upstream of in-channel structures as a function of hydrology, and to quantify the dampening of flood energy caused by erosion control structures and by the restoration of riparian vegetation. We are also able to create a surface water budget that constrains water storage and infiltration by monitoring streamflow at several places above, within, and downstream of restoration efforts. We also speculate on the resilience of such efforts. Quantifying the effects of the restoration efforts at Rancho San Bernardino may prove useful in guiding similar large-scale ecological restoration efforts elsewhere in degraded dryland landscapes.

Mercury cycling in agricultural and managed wetlands: a synthesis of methylmercury production, hydrologic export, and bioaccumulation from an integrated field study

USGS Publications Warehouse

Windham-Myers, Lisamarie; Fleck, Jacob A.; Ackerman, Joshua T.; Marvin-DiPasquale, Mark C.; Stricker, Craig A.; Heim, Wesley A.; Bachand, Philip A.M.; Eagles-Smith, Collin A.; Gill, Gary; Stephenson, Mark; Alpers, Charles N.

2014-01-01

With seasonal wetting and drying, and high biological productivity, agricultural wetlands (rice paddies) may enhance the conversion of inorganic mercury (Hg(II)) to methylmercury (MeHg), the more toxic, organic form that biomagnifies through food webs. Yet, the net balance of MeHg sources and sinks in seasonal wetland environments is poorly understood because it requires an annual, integrated assessment across biota, sediment, and water components. We examined a suite of wetlands managed for rice crops or wildlife during 2007–2008 in California's Central Valley, in an area affected by Hg contamination from historic mining practices. Hydrologic management of agricultural wetlands for rice, wild rice, or fallowed — drying for field preparation and harvest, and flooding for crop growth and post-harvest rice straw decay — led to pronounced seasonality in sediment and aqueous MeHg concentrations that were up to 95-fold higher than those measured concurrently in adjacent, non-agricultural permanently-flooded and seasonally-flooded wetlands. Flooding promoted microbial MeHg production in surface sediment of all wetlands, but extended water residence time appeared to preferentially enhance MeHg degradation and storage. When incoming MeHg loads were elevated, individual fields often served as a MeHg sink, rather than a source. Slow, horizontal flow of shallow water in the agricultural wetlands led to increased importance of vertical hydrologic fluxes, including evapoconcentration of surface water MeHg and transpiration-driven advection into the root zone, promoting temporary soil storage of MeHg. Although this hydrology limited MeHg export from wetlands, it also increased MeHg exposure to resident fish via greater in situ aqueous MeHg concentrations. Our results suggest that the combined traits of agricultural wetlands — slow-moving shallow water, manipulated flooding and drying, abundant labile plant matter, and management for wildlife — may enhance microbial methylation of Hg(II) and MeHg exposure to local biota, as well as export to downstream habitats during uncontrolled winter-flow events.

Mercury cycling in agricultural and managed wetlands: a synthesis of methylmercury production, hydrologic export, and bioaccumulation from an integrated field study.

PubMed

Windham-Myers, Lisamarie; Fleck, Jacob A; Ackerman, Joshua T; Marvin-DiPasquale, Mark; Stricker, Craig A; Heim, Wesley A; Bachand, Philip A M; Eagles-Smith, Collin A; Gill, Gary; Stephenson, Mark; Alpers, Charles N

2014-06-15

With seasonal wetting and drying, and high biological productivity, agricultural wetlands (rice paddies) may enhance the conversion of inorganic mercury (Hg(II)) to methylmercury (MeHg), the more toxic, organic form that biomagnifies through food webs. Yet, the net balance of MeHg sources and sinks in seasonal wetland environments is poorly understood because it requires an annual, integrated assessment across biota, sediment, and water components. We examined a suite of wetlands managed for rice crops or wildlife during 2007-2008 in California's Central Valley, in an area affected by Hg contamination from historic mining practices. Hydrologic management of agricultural wetlands for rice, wild rice, or fallowed - drying for field preparation and harvest, and flooding for crop growth and post-harvest rice straw decay - led to pronounced seasonality in sediment and aqueous MeHg concentrations that were up to 95-fold higher than those measured concurrently in adjacent, non-agricultural permanently-flooded and seasonally-flooded wetlands. Flooding promoted microbial MeHg production in surface sediment of all wetlands, but extended water residence time appeared to preferentially enhance MeHg degradation and storage. When incoming MeHg loads were elevated, individual fields often served as a MeHg sink, rather than a source. Slow, horizontal flow of shallow water in the agricultural wetlands led to increased importance of vertical hydrologic fluxes, including evapoconcentration of surface water MeHg and transpiration-driven advection into the root zone, promoting temporary soil storage of MeHg. Although this hydrology limited MeHg export from wetlands, it also increased MeHg exposure to resident fish via greater in situ aqueous MeHg concentrations. Our results suggest that the combined traits of agricultural wetlands - slow-moving shallow water, manipulated flooding and drying, abundant labile plant matter, and management for wildlife - may enhance microbial methylation of Hg(II) and MeHg exposure to local biota, as well as export to downstream habitats during uncontrolled winter-flow events. Published by Elsevier B.V.

New Data on mid-Miocene Rhyolite Volcanism in Eastern Oregon Extend Early, co-CRBG Rhyolite Flare up and Constrain Storage Sites of Grande Ronde Flood Basalts

NASA Astrophysics Data System (ADS)

Streck, M. J.; Ferns, M. L.; McIntosh, W. C.

2015-12-01

The classical view of relating mid-Miocene rhyolites of the tri-state area of Oregon, Nevada, and Idaho to the flood basalts of the Columbia River Basalt was that a mantle plume impinging along the Oregon-Idaho border first causes eruption of the flood basalts but shortly thereafter causes generation of rhyolites at the McDermitt volcanic field from which then hot-spot track rhyolites developed progressively younging towards Yellowstone. More recent work reveals rhyolites as old as found at McDermitt (~16.5 Ma) to occur along a wide E-W tangent along the Oregon-Nevada-Idaho border. And now, our data extend such early rhyolites (>16 Ma) to several locations further north within and in the periphery of the Lake Owyhee Volcanic Field (LOVF) adding to the geographically orphaned old age of 16.7 Ma of the Silver City Rhyolite, Idaho. Hence, the rhyolite flare-up associated with flood basalt magmatism occurred within a circular area of ~400 km centered 100 km NNE of McDermitt. Consequently, no south-to-north progression exists in the onset of rhyolite volcanism; instead, rhyolites started up at the same time over this large area. Province-wide rhyolite volcanism was strongest between ~16.4 and 15.4 Ma coincident with eruptions of the most voluminous member of the CRBG - the Grande Ronde Basalt (GRB). Field evidence for such bimodal volcanism consists of intercalated local GRB units with the Dinner Creek Tuff and Littlefield Rhyolite in the Malheur River Gorge corridor. GRB eruption sites exist and were likely fed from reservoirs residing below or near rhyolitic chambers. Presently, we have petrological evidence for pinning down GRB storages sites to areas from where rhyolites of the Dinner Creek Tuff and lava flows of the Littlefield Rhyolite erupted. In summary, input of GRG and other CRBG magmas were driving co-CRBG rhyolite volcanism which in turn may have influenced whether flood basalt magmas erupted locally or travelled in dikes to more distally located areas.

On the potential for CO2 mineral storage in continental flood basalts – PHREEQC batch- and 1D diffusion–reaction simulations

PubMed Central

2012-01-01

Continental flood basalts (CFB) are considered as potential CO2 storage sites because of their high reactivity and abundant divalent metal ions that can potentially trap carbon for geological timescales. Moreover, laterally extensive CFB are found in many place in the world within reasonable distances from major CO2 point emission sources. Based on the mineral and glass composition of the Columbia River Basalt (CRB) we estimated the potential of CFB to store CO2 in secondary carbonates. We simulated the system using kinetic dependent dissolution of primary basalt-minerals (pyroxene, feldspar and glass) and the local equilibrium assumption for secondary phases (weathering products). The simulations were divided into closed-system batch simulations at a constant CO2 pressure of 100 bar with sensitivity studies of temperature and reactive surface area, an evaluation of the reactivity of H2O in scCO2, and finally 1D reactive diffusion simulations giving reactivity at CO2 pressures varying from 0 to 100 bar. Although the uncertainty in reactive surface area and corresponding reaction rates are large, we have estimated the potential for CO2 mineral storage and identified factors that control the maximum extent of carbonation. The simulations showed that formation of carbonates from basalt at 40 C may be limited to the formation of siderite and possibly FeMg carbonates. Calcium was largely consumed by zeolite and oxide instead of forming carbonates. At higher temperatures (60 – 100 C), magnesite is suggested to form together with siderite and ankerite. The maximum potential of CO2 stored as solid carbonates, if CO2 is supplied to the reactions unlimited, is shown to depend on the availability of pore space as the hydration and carbonation reactions increase the solid volume and clog the pore space. For systems such as in the scCO2 phase with limited amount of water, the total carbonation potential is limited by the amount of water present for hydration of basalt. PMID:22697910

Evaluation of Seasonality in Shallow Groundwater Dynamics and Storage in an Urban Prairie Nature Preserve Using a High-Frequency Sensing Network

NASA Astrophysics Data System (ADS)

Rivera, V. A.; Hernandez-Gonzalez, L. M.; Phillips, C. B.; Nair, A.; Negri, M. C.; Gnaedinger, K. J.; Miller, W. M.; Packman, A. I.

2017-12-01

Changing regional climate applies stresses to urban areas in the form of altered weather patterns, requiring new strategies for stormwater runoff management and flood mitigation. At the same time, the proportion of people residing in urban areas is increasing and cities are turning to greenspace as a tool for managing runoff. Gensburg Markham Prairie (GMP), located in Markham, Illinois south of Chicago, is an urban prairie nature preserve and a U.S. National Natural Landmark. Owned by Northeastern Illinois University and managed by the Nature Conservancy, GMP receives runoff from surrounding urban areas and provides valuable stormwater storage, while also hosting high biodiversity and providing critical habitat for sensitive and endemic. A successful management strategy for GMP should preserve both of these valuable ecosystem services. To understand GMP's role within the urban environment, we installed a suite of instruments in 2016 and 2017 to measure surface and groundwater levels, rainfall, soil moisture, and electrical conductivity throughout the prairie. This monitoring network includes 40 sensors collecting high frequency data (every 30 minutes). We are also collecting monthly distributed surface and groundwater samples to quantify a range of anions and cations that signal potentially detrimental anthropogenic impacts on the prairie. In addition, we are using historical and ongoing plant distribution surveys to explore the interactions between spatial patterns in vegetation and water dynamics in the prairie. The high measurement frequency and large diversity of sensor types supports holistic investigation of the response of the prairie to diverse events, including summer thunderstorms, winter road salt runoff, and spring snowmelt. The 18 months of data collected to date reveals clear patterns in response to weather events with influence from soil type and spatial variables. We are using time-series analysis with MODFLOW modelling to explore surface-groundwater interactions within the site and the effects of seasonality on the prairie's capacity for storage of stormwater runoff. This analysis supports development of management strategies to preserve the prairie's ecological diversity and provide a basis for regional-scale design of green infrastructure for flood control.

Flood of January 19-20, 1996 in New York State

USGS Publications Warehouse

Lumia, Richard

1998-01-01

Heavy rain during January 18-19, 1996, combined with unseasonably warm temperatures that caused rapid snowmelt, resulted in widespread flooding throughout New York State. Damages to highways, bridges, and private property exceeded $100 million. The storm and flooding claimed 10 lives, stranded hundreds of people, destroyed or damaged thousands of homes and businesses, and closed hundreds of roads. Forty-one counties in New York were declared federal disaster areas. The most severely affected region was within and surrounding the Catskill Mountains. Damages and losses within Delaware County alone exceeded $20 million.More than 4.5 inches of rain fell on at least 45 inches of melting snow in the Catskill Mountain region during January 18-19 and caused major flooding in the area. The most destructive flooding was along Schoharie Creek and the East and West Branches of the Delaware River. Record peak discharges occurred at 57 U.S. Geological Survey streamflow-gaging stations throughout New York. Maximum discharges at 15 sites, mostly within the Schoharie Creek and Delaware River basins, had recurrence intervals equal to or greater than 100 years. The storage of significant amounts of floodwater in several reservoirs sharply reduced peak discharges downstream. This report presents a summary of peak stages and discharges, precipitation maps, floodflow hydrographs, inflow-outflow hydrographs for several reservoirs, and flood profiles along 83 miles of Schoharie Creek from its headwaters in the Catskill Mountains to its mouth at the Mohawk River.

Sediment Transport During Three Controlled-Flood Experiments on the Colorado River Downstream from Glen Canyon Dam, with Implications for Eddy-Sandbar Deposition in Grand Canyon National Park

USGS Publications Warehouse

Topping, David J.; Rubin, David M.; Grams, Paul E.; Griffiths, Ronald E.; Sabol, Thomas A.; Voichick, Nicholas; Tusso, Robert B.; Vanaman, Karen M.; McDonald, Richard R.

2010-01-01

Three large-scale field experiments were conducted on the Colorado River downstream from Glen Canyon Dam in 1996, 2004, and 2008 to evaluate whether artificial (that is, controlled) floods released from the dam could be used in conjunction with the sand supplied by downstream tributaries to rebuild and sustainably maintain eddy sandbars in the river in Grand Canyon National Park. Higher suspended-sand concentrations during a controlled flood will lead to greater eddy-sandbar deposition rates. During each controlled flood experiment, sediment-transport and bed-sediment data were collected to evaluate sediment-supply effects on sandbar deposition. Data collection substantially increased in spatial and temporal density with each subsequent experiment. The suspended- and bed-sediment data collected during all three controlled-flood experiments are presented and analyzed in this report. Analysis of these data indicate that in designing the hydrograph of a controlled flood that is optimized for sandbar deposition in a given reach of the Colorado River, both the magnitude and the grain size of the sand supply must be considered. Because of the opposing physical effects of bed-sand area and bed-sand grain size in regulating suspended-sand concentration, larger amounts of coarser sand on the bed can lead to lower suspended-sand concentrations, and thus lower rates of sandbar deposition, during a controlled flood than can lesser amounts of finer sand on the bed. Although suspended-sand concentrations were higher at all study sites during the 2008 controlled-flood experiment (CFE) than during either the 1996 or 2004 CFEs, these higher concentrations were likely associated with more sand on the bed of the Colorado River in only lower Glen Canyon. More sand was likely present on the bed of the river in Grand Canyon during the 1996 CFE than during either the 2004 or 2008 CFEs. The question still remains as to whether sandbars can be sustained in the Colorado River in Grand Canyon National Park through use of controlled floods in conjunction with typical amounts and grain sizes of sand supplied by the tributaries that enter the Colorado River downstream from Glen Canyon Dam.

Towards River Rehabilitation as AN Integrated Approach to Flood Management in Asian Cities

NASA Astrophysics Data System (ADS)

Higgitt, David L.

Flood management in Asian cities has conventionally been approached through structural intervention where floods are regarded as a threat requiring control through engineering infrastructure. Such a command and control paradigm represents a marked transition from the way that monsoon flood regimes have been traditionally perceived across Asia. Rapid urbanization and climate change has imposed increasingly difficult flood management challenges as an extension of impermeable surfaces generates rapid runoff and flash flooding, while cities expand into flood-prone areas. Property and communities are placed at enhanced risk. Urbanization reallocates risk as channel and floodplain modification influences flood regimes, while demands for flood protection at certain locations can redistribute risk to other areas. An increasing concern about flood hazard across Asian cities questions whether conventional solutions reliant on structural intervention are sustainable. Such questioning is mirrored by an alternative paradigm of rehabilitation in integrated river basin management — a recognition that restoring and sustaining functional river ecosystems with high biodiversity is one of the greatest challenges facing society. Rehabilitation initiatives demand a new approach to river basin management which encourage interdisciplinary activity, particularly between engineers, hydrologists, geomorphologists and ecologists. The paper sets out some preliminary ideas from a research project investigating the potential for river rehabilitation as a central tenet of flood management, with a particular focus on Asian cities.

76 FR 59121 - Notice of Availability of the Record of Decision for the Final Environmental Impact Statement...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-23

... lined open channels; grade control structures; bridges and drainage crossings; building pads; and water quality control facilities (sedimentation control, flood control, debris, and water quality basins). The... facilities (sedimentation control, flood debris, and water quality basins); regular and ongoing maintenance...

Model simulations of potential contribution of the proposed Huangpu Gate to flood control in the Lake Taihu basin of China

NASA Astrophysics Data System (ADS)

Zhang, Hanghui; Liu, Shuguang; Ye, Jianchun; Yeh, Pat J.-F.

2017-10-01

The Lake Taihu basin (36 895 km2), one of the most developed regions in China located in the hinterland of the Yangtze River Delta, has experienced increasing flood risk. The largest flood in history occurred in 1999 with a return period estimate of 200 years, considerably larger than the current capacity of the flood defense with a design return period of 50 years. Due to its flat saucer-like terrain, the capacity of the flood control system in this basin depends on flood control infrastructures and peripheral tidal conditions. The Huangpu River, an important river of the basin connecting Lake Taihu upstream and Yangtze River estuaries downstream, drains two-fifths of the entire basin. Since the water level in the Huangpu River is significantly affected by the high tide conditions in estuaries, constructing an estuary gate is considered an effective solution for flood mitigation. The main objective of this paper is to assess the potential contributions of the proposed Huangpu Gate to the flood control capacity of the basin. To achieve this goal, five different scenarios of flooding conditions and the associated gate operations are considered by using numerical model simulations. Results of quantitative analyses show that the Huangpu Gate is effective for evacuating floodwaters. It can help to reduce both peak values and duration of high water levels in Lake Taihu to benefit surrounding areas along the Taipu Canal and the Huangpu River. The contribution of the gate to the flood control capacity is closely associated with its operation modes and duration. For the maximum potential contribution of the gate, the net outflow at the proposed site is increased by 52 %. The daily peak level is decreased by a maximum of 0.12 m in Lake Taihu, by maxima of 0.26-0.37 and 0.46-0.60 m in the Taipu Canal and the Huangpu River, respectively, and by 0.05-0.39 m in the surrounding areas depending on the local topography. It is concluded that the proposed Huangpu Gate can reduce flood risk in the Lake Taihu basin, especially in those low-lying surrounding areas along the Taipu Canal and the Huangpu River significantly, which is of great benefit to the flood management in the basin and the Yangtze River Delta.

Mitigation of steam generator tube rupture in a pressurized water reactor with passive safety systems

DOEpatents

McDermott, D.J.; Schrader, K.J.; Schulz, T.L.

1994-05-03

The effects of steam generator tube ruptures in a pressurized water reactor are mitigated by reducing the pressure in the primary loop by diverting reactor coolant through the heat exchanger of a passive heat removal system immersed in the in containment refueling water storage tank in response to a high feed water level in the steam generator. Reactor coolant inventory is maintained by also in response to high steam generator level introducing coolant into the primary loop from core make-up tanks at the pressure in the reactor coolant system pressurizer. The high steam generator level is also used to isolate the start-up feed water system and the chemical and volume control system to prevent flooding into the steam header. 2 figures.

Pore-scale imaging of capillary trapped supercritical CO2 as controlled by water-wet vs. CO2-wet media and grain shapes

NASA Astrophysics Data System (ADS)

Chaudhary, K.; Cardenas, M.; Wolfe, W. W.; Maisano, J. A.; Ketcham, R. A.; Bennett, P.

2013-12-01

The capillary trapping of supercritical CO2 (s-CO2) is postulated to comprise up to 90% of permanently trapped CO2 injected during geologic sequestration. Successive s-CO2/brine flooding experiments under reservoir conditions showed that water-wet rounded beads trapped 15% of injected s-CO2 both as clusters and as individual ganglia, whereas CO2¬-wet beads trapped only 2% of the injected s-CO2 as minute pockets in pore constrictions. Angular water-wet grains trapped 20% of the CO2 but flow was affected by preferential flow. Thus, capillary trapping is a viable mechanism for the permanent CO2 storage, but its success is constrained by the media wettability.

Mitigation of steam generator tube rupture in a pressurized water reactor with passive safety systems

DOEpatents

McDermott, Daniel J.; Schrader, Kenneth J.; Schulz, Terry L.

1994-01-01

The effects of steam generator tube ruptures in a pressurized water reactor are mitigated by reducing the pressure in the primary loop by diverting reactor coolant through the heat exchanger of a passive heat removal system immersed in the in containment refueling water storage tank in response to a high feed water level in the steam generator. Reactor coolant inventory is maintained by also in response to high steam generator level introducing coolant into the primary loop from core make-up tanks at the pressure in the reactor coolant system pressurizer. The high steam generator level is also used to isolate the start-up feed water system and the chemical and volume control system to prevent flooding into the steam header. 2 figures.

Floods of December 1964 and January 1965 in the Far Western States; Part 1 Description

USGS Publications Warehouse

Waananen, A.O.; Harris, D.D.; Williams, R.C.

1971-01-01

The floods of December 1964 and January 1965 in the Far Western States were extreme; in many areas, the greatest in the history of recorded streamflow and substantially greater than those of December 1955. An unusually large area--Oregon, most of Idaho, northern California, southern Washington, and small areas in western and northern Nevada--was involved. It exceeded the area flooded in 1955. Outstanding features included recordbreaking peak discharges, high sediment concentrations, large sediment loads, and extensive flood damage. The loss of 47 lives and direct property damage of more than $430 million was attributable to the floods. Yet, storage in reservoirs and operation of flood-control facilities were effective in preventing far greater damages in many areas, particularly in the Central Valley in California and the Willamette River basin in Oregon. The floods were caused by three principal storms during the period December 19 to January 31. The December 19-23 storm was the greatest in overall intensity and areal extent. Crests occurred on many major streams December 23, 1964, 9 years to the day after the great flood of December 23, 1955. The January 2-7 storm produced extreme floods in some basins in California. The January 21-31 storm produced maximum stages in some streams in northeastern Oregon and southeastern Washington and a repetition of high flows in part of the Willamette River basin and in some basins in coastal Oregon. All the storms, and particularly the warm torrential rain December 21-23, reflected the combined effect of moist unstable airmasses, strong west-southwest winds, and mountain ranges oriented nearly at right angles to the flow of air. High air temperatures and strong winds associated with the storms caused melting of snow, and the meltwater augmented the rain that fell on frozen ground. The coastal areas of northern California and southern Oregon had measurable rain on as many as 50 days in December and January. A maximum precipitation of nearly 69 inches in the 2-month period was recorded in southern Oregon, and recorded runoff at several streamflow-measurement stations indicates that greater precipitation probably occurred at higher altitudes in these areas. Flood runoff in streams, not affected by regulation, exceeded any previously recorded throughout much of the area. Some streams that had particularly notable floods are: Deep and Plush Creeks in the Great Basin ix Oregon, where the maximum flows were nearly twice those of the record floods of 1963 ; Thomes Creek, a west-side Sacramento River tributary in the Central Valley, where the maximum flow was 160 percent of the record peak of 1955; Eel, Klamath, and Smith Rivers in north-coastal California, where the catastrophic peak flows were about 1-1/3 times the floods of 1955 and the legendary winter floods of 1861-62 and inundated, damaged, or destroyed nearly all communities along the main rivers; Grande Ronde River in the lower Snake River basin, where the peak discharge at La Grande was 1.6 times the previous maximum flow during 57 years of record; John Day River in the lower Columbia River basin, where the peak discharge at the McDonald Ferry gaging station exceeded the historic peak of 1894; many Willamette River tributaries, where maximum flows exceeded previous record flows; and the Rogue River in coastal Oregon, where the maximum flow of about 500,000 cfs below the Illinois River near Agness was 86,000 cfs greater than the previous maximum in a 74-year record. The partly regulated flow of the Willamette River far exceeded that in 1955. The suspended-sediment concentration and load of most streams greatly exceeded any that had been measured previously in the flood area. In Idaho, Washington, and Oregon, the ground thaw that preceded the period of high runoff resulted in conditions conducive to severe erosion of the uplands and subsequent deposition on flooded stream terraces. The greatest concentrations of suspended sedimen

Effects of prolonged storage on survival and growth of outplanted bottomland oaks

Treesearch

David C. Mercker; David S. Buckley; John P. Conn

2011-01-01

A prominent difficulty during bottomland hardwood afforestation is that sites are often flooded during the preferred months of planting (January-March), which results in delayed planting (April-June) and reduced survival. We monitored growth and survival of oak seedlings planted in 11 different months (February through December) after varying periods of humidified cold...

A probabilistic approach to modeling postfire erosion after the 2009 Australian bushfires

Treesearch

P. R. Robichaud; W. J. Elliot; F. B. Pierson; D. E. Hall; C. A. Moffet

2009-01-01

Major concerns after bushfires and wildfires include increased flooding, erosion and debris flows due to loss of the protective forest floor layer, loss of water storage, and creation of water repellent soil conditions. To assist postfire assessment teams in their efforts to evaluate fire effects and make postfire treatment decisions, a web-based Erosion Risk...

ABLE project: Development of an advanced lead-acid storage system for autonomous PV installations

NASA Astrophysics Data System (ADS)

Lemaire-Potteau, Elisabeth; Vallvé, Xavier; Pavlov, Detchko; Papazov, G.; Borg, Nico Van der; Sarrau, Jean-François

In the advanced battery for low-cost renewable energy (ABLE) project, the partners have developed an advanced storage system for small and medium-size PV systems. It is composed of an innovative valve-regulated lead-acid (VRLA) battery, optimised for reliability and manufacturing cost, and an integrated regulator, for optimal battery management and anti-fraudulent use. The ABLE battery performances are comparable to flooded tubular batteries, which are the reference in medium-size PV systems. The ABLE regulator has several innovative features regarding energy management and modular series/parallel association. The storage system has been validated by indoor, outdoor and field tests, and it is expected that this concept could be a major improvement for large-scale implementation of PV within the framework of national rural electrification schemes.

Systematic flood modelling to support flood-proof urban design

NASA Astrophysics Data System (ADS)

Bruwier, Martin; Mustafa, Ahmed; Aliaga, Daniel; Archambeau, Pierre; Erpicum, Sébastien; Nishida, Gen; Zhang, Xiaowei; Pirotton, Michel; Teller, Jacques; Dewals, Benjamin

2017-04-01

Urban flood risk is influenced by many factors such as hydro-meteorological drivers, existing drainage systems as well as vulnerability of population and assets. The urban fabric itself has also a complex influence on inundation flows. In this research, we performed a systematic analysis on how various characteristics of urban patterns control inundation flow within the urban area and upstream of it. An urban generator tool was used to generate over 2,250 synthetic urban networks of 1 km2. This tool is based on the procedural modelling presented by Parish and Müller (2001) which was adapted to generate a broader variety of urban networks. Nine input parameters were used to control the urban geometry. Three of them define the average length, orientation and curvature of the streets. Two orthogonal major roads, for which the width constitutes the fourth input parameter, work as constraints to generate the urban network. The width of secondary streets is given by the fifth input parameter. Each parcel generated by the street network based on a parcel mean area parameter can be either a park or a building parcel depending on the park ratio parameter. Three setback parameters constraint the exact location of the building whithin a building parcel. For each of synthetic urban network, detailed two-dimensional inundation maps were computed with a hydraulic model. The computational efficiency was enhanced by means of a porosity model. This enables the use of a coarser computational grid , while preserving information on the detailed geometry of the urban network (Sanders et al. 2008). These porosity parameters reflect not only the void fraction, which influences the storage capacity of the urban area, but also the influence of buildings on flow conveyance (dynamic effects). A sensitivity analysis was performed based on the inundation maps to highlight the respective impact of each input parameter characteristizing the urban networks. The findings of the study pinpoint which properties of urban networks have a major influence on urban inundation flow, enabling better informed flood-proof urban design. References: Parish, Y. I. H., Muller, P. 2001. Procedural modeling of cities. SIGGRAPH, pp. 301—308. Sanders, B.F., Schubert, J.E., Gallegos, H.A., 2008. Integral formulation of shallow-water equations with anisotropic porosity for urban flood modeling. Journal of Hydrology 362, 19-38. Acknowledgements: The research was funded through the ARC grant for Concerted Research Actions, financed by the Wallonia-Brussels Federation.

Flood triggering in Switzerland: the role of daily to monthly preceding precipitation

NASA Astrophysics Data System (ADS)

Froidevaux, P.; Schwanbeck, J.; Weingartner, R.; Chevalier, C.; Martius, O.

2015-09-01

Determining the role of different precipitation periods for peak discharge generation is crucial for both projecting future changes in flood probability and for short- and medium-range flood forecasting. In this study, catchment-averaged daily precipitation time series are analyzed prior to annual peak discharge events (floods) in Switzerland. The high number of floods considered - more than 4000 events from 101 catchments have been analyzed - allows to derive significant information about the role of antecedent precipitation for peak discharge generation. Based on the analysis of precipitation times series, a new separation of flood-related precipitation periods is proposed: (i) the period 0 to 1 day before flood days, when the maximum flood-triggering precipitation rates are generally observed, (ii) the period 2 to 3 days before flood days, when longer-lasting synoptic situations generate "significantly higher than normal" precipitation amounts, and (iii) the period from 4 days to 1 month before flood days when previous wet episodes may have already preconditioned the catchment. The novelty of this study lies in the separation of antecedent precipitation into the precursor antecedent precipitation (4 days before floods or earlier, called PRE-AP) and the short range precipitation (0 to 3 days before floods, a period when precipitation is often driven by one persistent weather situation like e.g., a stationary low-pressure system). A precise separation of "antecedent" and "peak-triggering" precipitation is not attempted. Instead, the strict definition of antecedent precipitation periods permits a direct comparison of all catchments. The precipitation accumulating 0 to 3 days before an event is the most relevant for floods in Switzerland. PRE-AP precipitation has only a weak and region-specific influence on flood probability. Floods were significantly more frequent after wet PRE-AP periods only in the Jura Mountains, in the western and eastern Swiss plateau, and at the outlet of large lakes. As a general rule, wet PRE-AP periods enhance the flood probability in catchments with gentle topography, high infiltration rates, and large storage capacity (karstic cavities, deep soils, large reservoirs). In contrast, floods were significantly less frequent after wet PRE-AP periods in glacial catchments because of reduced melt. For the majority of catchments however, no significant correlation between precipitation amounts and flood occurrences is found when the last 3 days before floods are omitted in the precipitation amounts. Moreover, the PRE-AP was not higher for extreme floods than for annual floods with a high frequency and was very close to climatology for all floods. The fact that floods are not significantly more frequent nor more intense after wet PRE-AP is a clear indicator of a short discharge memory of Pre-Alpine, Alpine and South Alpine Swiss catchments. Our study poses the question whether the impact of long-term precursory precipitation for floods in such catchments is not overestimated in the general perception. The results suggest that the consideration of a 3-4 days precipitation period should be sufficient to represent (understand, reconstruct, model, project) Swiss Alpine floods.

Flood triggering in Switzerland: the role of daily to monthly preceding precipitation

NASA Astrophysics Data System (ADS)

Froidevaux, P.; Schwanbeck, J.; Weingartner, R.; Chevalier, C.; Martius, O.

2015-03-01

Determining the role of different precipitation periods for peak discharge generation is crucial for both projecting future changes in flood probability and for short- and medium-range flood forecasting. We analyze catchment-averaged daily precipitation time series prior to annual peak discharge events (floods) in Switzerland. The high amount of floods considered - more than 4000 events from 101 catchments have been analyzed - allows to derive significant information about the role of antecedent precipitation for peak discharge generation. Based on the analysis of precipitation times series, we propose a new separation of flood-related precipitation periods: (i) the period 0 to 1 day before flood days, when the maximum flood-triggering precipitation rates are generally observed, (ii) the period 2 to 3 days before flood days, when longer-lasting synoptic situations generate "significantly higher than normal" precipitation amounts, and (iii) the period from 4 days to one month before flood days when previous wet episodes may have already preconditioned the catchment. The novelty of this study lies in the separation of antecedent precipitation into the precursor antecedent precipitation (4 days before floods or earlier, called PRE-AP) and the short range precipitation (0 to 3 days before floods, a period when precipitation is often driven by one persistent weather situation like e.g. a stationary low-pressure system). Because we consider a high number of events and because we work with daily precipitation values, we do not separate the "antecedent" and "peak-triggering" precipitation. The whole precipitation recorded during the flood day is included in the short-range antecedent precipitation. The precipitation accumulating 0 to 3 days before an event is the most relevant for floods in Switzerland. PRE-AP precipitation has only a weak and region-specific influence on flood probability. Floods were significantly more frequent after wet PRE-AP periods only in the Jura Mountains, in the western and eastern Swiss plateau, and at the exit of large lakes. As a general rule, wet PRE-AP periods enhance the flood probability in catchments with gentle topography, high infiltration rates, and large storage capacity (karstic cavities, deep soils, large reservoirs). In contrast, floods were significantly less frequent after wet PRE-AP periods in glacial catchments because of reduced melt. For the majority of catchments however, no significant correlation between precipitation amounts and flood occurrences is found when the last three days before floods are omitted in the precipitation amounts. Moreover, the PRE-AP was not higher for extreme floods than for annual floods with a high frequency and was very close to climatology for all floods. The weak influence of PRE-AP is a clear indicator of a short discharge memory of Prealpine, Alpine and Southalpine Swiss catchments. Our study nevertheless poses the question whether the impact of long-term precursory precipitation for floods in such catchments is not overestimated in the general perception. We conclude that the consideration of a 3-4 days precipitation period should be sufficient to represent (understand, reconstruct, model, project) Swiss Alpine floods.

Establishment of Rio Grande cottonwood seedlings using micro-irrigation of xeric flood plain sites

Treesearch

David R. Dreesen; Gregory A. Fenchel; Joseph G. Fraser

1999-01-01

Flood control, irrigation structures, and flow control practices on the Middle Rio Grande have prevented the deposition of sediments and hydrologic conditions conducive to the germination and establishment of Rio Grande cottonwood (Populus fremontii S. Wats.). The Los Lunas Plant Materials Center has been investigating the use of micro-irrigation systems on xeric flood...

Anthropogenic impact on flood-risk: a large-scale assessment for planning controlled inundation strategies along the River Po

NASA Astrophysics Data System (ADS)

Domeneghetti, Alessio; Castellarin, Attilio; Brath, Armando

2013-04-01

The European Flood Directive (2007/60/EC) has fostered the development of innovative and sustainable approaches and methodologies for flood-risk mitigation and management. Furthermore, concerning flood-risk mitigation, the increasing awareness of how the anthropogenic pressures (e.g. demographic and land-use dynamics, uncontrolled urban and industrial expansion on flood-prone area) could strongly increase potential flood damages and losses has triggered a paradigm shift from "defending the territory against flooding" (e.g. by means of levee system strengthening and heightening) to "living with floods" (e.g. promoting compatible land-uses or adopting controlled flooding strategies of areas located outside the main embankments). The assessment of how socio-economic dynamics may influence flood-risk represents a fundamental skill that should be considered for planning a sustainable industrial and urban development of flood-prone areas, reducing their vulnerability and therefore minimizing socio-economic and ecological losses due to large flood events. These aspects, which are of fundamental importance for Institutions and public bodies in charge of Flood Directive requirements, need to be considered through a holistic approach at river basin scale. This study focuses on the evaluation of large-scale flood-risk mitigation strategies for the middle-lower reach of River Po (~350km), the longest Italian river and the largest in terms of streamflow. Due to the social and economical importance of the Po River floodplain (almost 40% of the total national gross product results from this area), our study aims at investigating the potential of combining simplified vulnerability indices with a quasi-2D model for the definition of sustainable and robust flood-risk mitigation strategies. Referring to past (1954) and recent (2006) land-use data sets (e.g. CORINE) we propose simplified vulnerability indices for assessing potential flood-risk of industrial and urbanized flood prone areas taking into account altimetry and population density, and we analyze the modification of flood-risk occurred during last decades due to the demographic dynamics of the River Po floodplains. Flood hazard associated to a high magnitude event (i.e. return period of about 500 year) was estimated by means of a quasi-2D hydraulic model set up for the middle-lower portion of the Po River and for its major tributaries. The results of the study highlight how coupling a large-scale numerical model with the proposed flood-vulnerability indices could be a useful tool for decision-makers when they are called to define sustainable spatial development plans for the study area, or when they need to identify priorities in the organization of civil protection actions during a major flood event that could include the necessity of controlled flooding of flood-prone areas located outside the main embankment system.

Hydrologic and Temporal Influences of Evaporite Minerals on the Vertical Distribution, Storage, and Mobility of Uranium

NASA Astrophysics Data System (ADS)

Roycroft, S. J.; Noel, V.; Boye, K.; Besancon, C.; Weaver, K. L.; Johnson, R. H.; Dam, W. L.; Fendorf, S. E.; Bargar, J.

2016-12-01

Uranium contaminated groundwater in Riverton, Wyoming persists despite anticipated natural attenuation outside of a former uranium ore processing facility. The inability of natural flushing to dilute the uranium below the regulatory threshold indicates that sediments act as secondary sources likely (re)supplying uranium to groundwater. Throughout the contaminated floodplain, uranium rich-evaporites are readily abundant in the upper 2 m of sediments and are spatially coincident with the location of the plume, which suggests a likely link between evaporites and increased uranium levels. Knowledge of where and how uranium is stored within evaporite-associated sediments is required to understand processes controlling the mobility of uranium. We expect that flooding and seasonal changes in hydrologic conditions will affect U phase partitioning, and thus largely control U mobility. The primary questions we are addressing in this project are: What is the relative abundance of uranium incorporated in various mineral complexes throughout the evaporite sediments? How do the factors of depth, location, and seasonality influence the relative incorporation, mobility and speciation of uranium?We have systematically sampled from two soil columns over three dates in Riverton. The sampling dates span before and after a significant flooding event, providing insight into the flood's impact on local uranium mobility. Sequential chemical extractions are used to decipher the reactivity of uranium and approximate U operationally defined within reactants targeting carbonate, silicate, organic, and metal oxide bound or water and exchangeable phases. Extractions throughout the entirety of the sediment cores provide a high-resolution vertical profile of the distribution of uranium in various extracted phases. Throughout the profile, the majority (50-60%) of uranium is bound within carbonate-targeted extracts, a direct effect of the carbonate-rich evaporite sediments. The sum of our analyses provide a dynamic model of uranium incorporation within evaporite sediments holding implications for the fate of uranium throughout contaminated sites across the Colorado River Basin.

Geomorphic variation in riparian tree mortality and stream coarse woody debris recruitment from record flooding in a coastal plain stream

Treesearch

Brian J. Palik; Stephen W. Golladay; P. Charles Goebel; Brad W. Taylor

1998-01-01

Large floods are an important process controlling the structure and function of stream ecosystems. One of the ways floods affect streams is through the recruitment of coarse woody debris from stream-side forests. Stream valley geomorphology may mediate this interaction by altering flood velocity, depth, and duration. Little research has examined how floods and...

Wind erodibility response of physical and biological crusts to rain and flooding

NASA Astrophysics Data System (ADS)

Aubault, H.; Bullard, J. E.; Strong, C. L.; Ghadiri, H.; McTainsh, G. H.

2015-12-01

Soil surface crusts are important controllers of the small-scale wind entrainment processes that occur across all dust source regions globally. The crust type influences water and wind erosion by impacting infiltration, runoff, threshold wind velocity and surface storage capacity of both water and loose erodible material. The spatial and temporal patterning of both physical and biological crusts is known to change with rainfall and flooding. However, little is known about the impact of differing water quantity (from light rainfall through to flooding) on soil crusting characteristics (strength, roughness, sediment loss). This study compares the response of two soil types (loamy sand - LS, sandy loam - SL) with and without BSCs to three different rainfall events (2mm, 8mm, 15mm). Two BSC treatments were used one that simulated a young cyanobacteria dominated crust and an older flood induced multi species biological crust. For both soil types, soil surface strength increased with increasing rainfall amount with LS having consistently higher resistance to rupture than SL. Regardless of texture, soils with BSCs were more resistant and strength did not change in response to rainfall impact. Soil loss due to wind erosion was substantially higher on bare LS (4 times higher) and SL (3 times higher) soils compared with those with BSCs. Our results also show that young biological crust (formed by the rainfall event) have reduced soil erodibility with notably greater strength, roughness and reduced sediment losses when compared to soils with physical crust. Interestingly though, the erodibility of the old BSC did not differ greatly from that of the young BSC with respect to strength, roughness and sediment loss. This raises questions regarding the rapid soil surface protection offered by young colonising cyanobacteria crusts. Further analyses exploring the role of biological soil crusts on surface response to rainfall and wind saltation impact are ongoing.

Mapping technological and biophysical capacities of watersheds to regulate floods

USGS Publications Warehouse

Mogollón, Beatriz; Villamagna, Amy M.; Frimpong, Emmanuel A.; Angermeier, Paul

2016-01-01

Flood regulation is a widely valued and studied service provided by watersheds. Flood regulation benefits people directly by decreasing the socio-economic costs of flooding and indirectly by its positive impacts on cultural (e.g., fishing) and provisioning (e.g., water supply) ecosystem services. Like other regulating ecosystem services (e.g., pollination, water purification), flood regulation is often enhanced or replaced by technology, but the relative efficacy of natural versus technological features in controlling floods has scarcely been examined. In an effort to assess flood regulation capacity for selected urban watersheds in the southeastern United States, we: (1) used long-term flood records to assess relative influence of technological and biophysical indicators on flood magnitude and duration, (2) compared the widely used runoff curve number (RCN) approach for assessing the biophysical capacity to regulate floods to an alternative approach that acknowledges land cover and soil properties separately, and (3) mapped technological and biophysical flood regulation capacities based on indicator importance-values derived for flood magnitude and duration. We found that watersheds with high biophysical (via the alternative approach) and technological capacities lengthened the duration and lowered the peak of floods. We found the RCN approach yielded results opposite that expected, possibly because it confounds soil and land cover processes, particularly in urban landscapes, while our alternative approach coherently separates these processes. Mapping biophysical (via the alternative approach) and technological capacities revealed great differences among watersheds. Our study improves on previous mapping of flood regulation by (1) incorporating technological capacity, (2) providing high spatial resolution (i.e., 10-m pixel) maps of watershed capacities, and (3) deriving importance-values for selected landscape indicators. By accounting for technology that enhances or replaces natural flood regulation, our approach enables watershed managers to make more informed choices in their flood-control investments.

Will building new reservoirs always help increase the water supply reliability? - insight from a modeling-based global study

NASA Astrophysics Data System (ADS)

Zhuang, Y.; Tian, F.; Yigzaw, W.; Hejazi, M. I.; Li, H. Y.; Turner, S. W. D.; Vernon, C. R.

2017-12-01

More and more reservoirs are being build or planned in order to help meet the increasing water demand all over the world. However, is building new reservoirs always helpful to water supply? To address this question, the river routing module of Global Change Assessment Model (GCAM) has been extended with a simple yet physical-based reservoir scheme accounting for irrigation, flood control and hydropower operations at each individual reservoir. The new GCAM river routing model has been applied over the global domain with the runoff inputs from the Variable Infiltration Capacity Model. The simulated streamflow is validated at 150 global river basins where the observed streamflow data are available. The model performance has been significantly improved at 77 basins and worsened at 35 basins. To facilitate the analysis of additional reservoir storage impacts at the basin level, a lumped version of GCAM reservoir model has been developed, representing a single lumped reservoir at each river basin which has the regulation capacity of all reservoir combined. A Sequent Peak Analysis is used to estimate how much additional reservoir storage is required to satisfy the current water demand. For basins with water deficit, the water supply reliability can be improved with additional storage. However, there is a threshold storage value at each basin beyond which the reliability stops increasing, suggesting that building new reservoirs will not help better relieve the water stress. Findings in the research can be helpful to the future planning and management of new reservoirs.

How do Watershed Characteristics and Precipitation Influence Post-Wildfire Valley Sediment Storage and Delivery Over Time?

NASA Astrophysics Data System (ADS)

Brogan, D. J.; Nelson, P. A.; MacDonald, L. H.

2016-12-01

Considerable advances have been made in understanding post-wildfire runoff, erosion, and mass wasting at the hillslope and small watershed scale, but the larger-scale effects on flooding, water quality, and sedimentation are often the most significant impacts. The problem is that we have virtually no watershed-specific tools to quantify the proportion of eroded sediment that is stored or delivered from watersheds larger than about 2-5 km2. In this study we are quantifying how channel and valley bottom characteristics affect post-wildfire sediment storage and delivery. Our research is based on intensive monitoring of sediment storage over time in two 15 km2 watersheds (Skin Gulch and Hill Gulch) burned in the 2012 High Park Fire using repeated cross section and longitudinal surveys from fall 2012 through summer 2016, five airborne laser scanning (ALS) datasets from fall 2012 through summer 2015, and both radar and ground-based precipitation measurements. We have computed changes in sediment storage by differencing successive cross sections, and computed spatially explicit changes in successive ALS point clouds using the multiscale model to model cloud comparison (M3C2) algorithm. These channel changes are being related to potential morphometric controls, including valley width, valley slope, confinement, contributing area, valley expansion or contraction, topographic curvature (planform and profile), and estimated sediment inputs. We hypothesize that maximum rainfall intensity and lateral confinement will be the primary independent variables that describe observed patterns of erosion and deposition, and that the results can help predict post-wildfire sediment delivery and identify high priority areas for restoration.

Proteomic analysis of soybean hypocotyl during recovery after flooding stress.

PubMed

Khan, Mudassar Nawaz; Sakata, Katsumi; Komatsu, Setsuko

2015-05-21

Soybean is a nutritionally important crop, but exhibits reduced growth and yields under flooding stress. To investigate soybean responses during post-flooding recovery, a gel-free proteomic technique was used to examine the protein profile in the hypocotyl. Two-day-old soybeans were flooded for 2 days and hypocotyl was collected under flooding and during the post-flooding recovery period. A total of 498 and 70 proteins were significantly changed in control and post-flooding recovering soybeans, respectively. Based on proteomic and clustering analyses, three proteins were selected for mRNA expression and enzyme activity assays. Pyruvate kinase was increased under flooding, but gradually decreased during post-flooding recovery period at protein abundance, mRNA, and enzyme activity levels. Nucleotidylyl transferase was decreased under flooding and increased during post-flooding recovery at both mRNA expression and enzyme activity levels. Beta-ketoacyl reductase 1 was increased under flooding and decreased during recovery at protein abundance and mRNA expression levels, but its enzyme activity gradually increased during the post-flooding recovery period. These results suggest that pyruvate kinase, nucleotidylyl transferase, and beta-ketoacyl reductase play key roles in post-flooding recovery in soybean hypocotyl by promoting glycolysis for the generation of ATP and regulation of secondary metabolic pathways. This study analyzed post-flooding recovery response mechanisms in soybean hypocotyl, which is a model organ for studying secondary growth, using a gel-free proteomic technique. Mass spectrometry analysis of proteins extracted from soybean hypocotyls identified 20 common proteins between control and flooding-stressed soybeans that changed significantly in abundance over time. The hypocotyl proteins that changed during post-flooding recovery were assigned to protein, development, secondary metabolism, and glycolysis categories. The analysis revealed that three proteins, pyruvate kinase, nucleotidylyl transferase, and beta-ketoacyl reductase, were increased in hypocotyl under flooding conditions and during post-flooding recovery. The proteins are involved in glycolysis, nucleotide synthesis and amino acid activation, and complex fatty acid biosynthesis. Copyright © 2015 Elsevier B.V. All rights reserved.

Analysis of flood hazard under consideration of dike breaches

NASA Astrophysics Data System (ADS)

Vorogushyn, S.; Apel, H.; Lindenschmidt, K.-E.; Merz, B.

2009-04-01

The study focuses on the development and application of a new modelling system which allows a comprehensive flood hazard assessment along diked river reaches under consideration of dike failures. The proposed Inundation Hazard Assessment Model (IHAM) represents a hybrid probabilistic-deterministic model. It comprises three models interactively coupled at runtime. These are: (1) 1D unsteady hydrodynamic model of river channel and floodplain flow between dikes, (2) probabilistic dike breach model which determines possible dike breach locations, breach widths and breach outflow discharges, and (3) 2D raster-based diffusion wave storage cell model of the hinterland areas behind the dikes. Due to the unsteady nature of the 1D and 2D coupled models, the dependence between hydraulic load at various locations along the reach is explicitly considered. The probabilistic dike breach model describes dike failures due to three failure mechanisms: overtopping, piping and slope instability caused by the seepage flow through the dike core (micro-instability). Dike failures for each mechanism are simulated based on fragility functions. The probability of breach is conditioned by the uncertainty in geometrical and geotechnical dike parameters. The 2D storage cell model driven by the breach outflow boundary conditions computes an extended spectrum of flood intensity indicators such as water depth, flow velocity, impulse, inundation duration and rate of water rise. IHAM is embedded in a Monte Carlo simulation in order to account for the natural variability of the flood generation processes reflected in the form of input hydrographs and for the randomness of dike failures given by breach locations, times and widths. The scenario calculations for the developed synthetic input hydrographs for the main river and tributary were carried out for floods with return periods of T = 100; 200; 500; 1000 a. Based on the modelling results, probabilistic dike hazard maps could be generated that indicate the failure probability of each discretised dike section for every scenario magnitude. Besides the binary inundation patterns that indicate the probability of raster cells being inundated, IHAM generates probabilistic flood hazard maps. These maps display spatial patterns of the considered flood intensity indicators and their associated return periods. The probabilistic nature of IHAM allows for the generation of percentile flood hazard maps that indicate the median and uncertainty bounds of the flood intensity indicators. The uncertainty results from the natural variability of the flow hydrographs and randomness of dike breach processes. The same uncertainty sources determine the uncertainty in the flow hydrographs along the study reach. The simulations showed that the dike breach stochasticity has an increasing impact on hydrograph uncertainty in downstream direction. Whereas in the upstream part of the reach the hydrograph uncertainty is mainly stipulated by the variability of the flood wave form, the dike failures strongly shape the uncertainty boundaries in the downstream part of the reach. Finally, scenarios of polder deployment for the extreme floods with T = 200; 500; 1000 a were simulated with IHAM. The results indicate a rather weak reduction of the mean and median flow hydrographs in the river channel. However, the capping of the flow peaks resulted in a considerable reduction of the overtopping failures downstream of the polder with a simultaneous slight increase of the piping and slope micro-instability frequencies explained by a more durable average impoundment. The developed IHAM simulation system represents a new scientific tool for studying fluvial inundation dynamics under extreme conditions incorporating effects of technical flood protection measures. With its major outputs in form of novel probabilistic inundation and dike hazard maps, the IHAM system has a high practical value for decision support in flood management.

Monitoring on The Quality and Quantity of DIY Rainwater Harvesting System

NASA Astrophysics Data System (ADS)

Kasmin, H.; Bakar, N. H.; Zubir, M. M.

2016-07-01

Rainwater harvesting is an alternative sources of water supply and can be used for potable and non-potable uses. It could helps to store treated rainwater for more beneficial use and also for flood mitigation. Sustainable approach for flooding problem reduction in urban areas is by slowing down the rate of surface runoff flows at source by providing more storage area/tank. In order to understand the performance of a rainwater harvesting system (RWH), a preliminary monitoring on a ‘do it yourself’ (DIY) RWH model with additional first -flush strategy for water quality treatment was done. The main concept behind first flush diversion is to prevent initial polluted rainwater from entering the storage tank. Based on seven rainfall events observed in Parit Raja, both quality and quantity of the rainfalls were analysed. For rainwater quality, the samples from first flush diverter and storage tank were taken to understand their performance based on pH, dissolved oxygen (DO), turbidity, total dissolved solid (TDS), total suspended solid (TSS), chemical oxygen demand (COD) and biochemical oxygen demand (BOD) parameters. While for rainwater quantity, hydrograph analysis were done based on the performance of total rainfall and runoff, peak flow of rainfall and runoff; and delayed time parameters. Based on Interim National Water Quality Standard (INWQS) and National Drinking Water Quality Standard (NDWQS), first flush diverter apparently helps on water quality improvement in storage tanks when pH, DO, TDS, TSS and turbidity were classified as Class I (INWQS) and is allowable for drinking; but BOD and COD parameters were classified as Class III (INWQS). Hence, it has potential to be used as potable usage but will need extensive treatment to reduce its poor microbial quality. Based on the maximum observed rainfall event which had total volume of 3195.5 liter, had peakflow reduction from 0.00071 m3/s to 0.00034 m3/s and delayed runoff between 5 and 10 minutes after rainfall started. It concludes that the performance of water retention could be due to total rainfall and the tank capacity. Therefore, RWH has a potential to be used as potable use and at the same time it also has a potential to reduce local urban flooding.

Mitigation of Flood Hazards Through Modification of Urban Channels and Floodplains

NASA Astrophysics Data System (ADS)

Miller, A. J.; Lee, G.; Bledsoe, B. P.; Stephens, T.

2017-12-01

Small urban watersheds with high percent impervious cover and dense road and storm-drain networks are highly responsive to short-duration high-intensity rainfall events that lead to flash floods. The Baltimore metropolitan area has some of the flashiest urban watersheds in the conterminous U.S., high frequency of channel incision in affected areas, and a large number of watershed restoration projects designed to restore ecosystem services through reconnection of the channel with the floodplain. A question of key importance in these and other urban watersheds is to what extent we can mitigate flood hazards and urban stream syndrome through restoration activities that modify the channel and valley floor. Local and state governments have invested resources in repairing damage caused by extreme events like the July 30, 2016 Ellicott City flood in the Tiber River watershed, as well as more frequent high flows in other local urban streams. Recent reports have investigated how much flood mitigation may be achieved through modification of the channel and floodplain to enhance short-term storage of flood waters on the valley floor or in other subsurface structures, as compared with increasing stormwater management in the headwaters. Ongoing research conducted as part of the UWIN (Urban Water Innovation Network) program utilizes high-resolution topographic point clouds derived by processing of photographs from hand-held cameras or video frames from drone overflights. These are used both to track geomorphic change and to assess flood response with 2d hydraulic modeling tools under alternative mitigation scenarios. Assessment metrics include variations in inundation extent, water depth, hydrograph attenuation, and temporal and spatial characteristics of the 2d depth-averaged velocity field. Examples from diverse urban watersheds are presented to illustrate the range of anticipated outcomes and potential constraints on the effectiveness of downstream vs. headwater mitigation efforts.

Performance of Oil Infrastructure during Hurricane Harvey

NASA Astrophysics Data System (ADS)

Bernier, C.; Kameshwar, S.; Padgett, J.

2017-12-01

Three major refining centers - Corpus Christi, Houston, and Beaumont/Port Arthur - were affected during Hurricane Harvey. Damage to oil infrastructure, especially aboveground storage tanks (ASTs), caused the release of more than a million gallons of hazardous chemicals in the environment. The objective of this presentation is to identify and gain a better understanding of the different damage mechanisms that occurred during Harvey in order to avoid similar failures during future hurricane events. First, a qualitative description of the damage suffered by ASTs during Hurricane Harvey is presented. Analysis of aerial imagery and incident reports indicate that almost all spills were caused by rainfall and the associated flooding. The largest spill was caused by two large ASTs that floated due to flooding in the Houston Ship Channel releasing 500,000 gallons of gasoline. The vulnerability of ASTs subjected to flooding was already well known and documented from previous storm events. In addition to flooding, Harvey also exposed the vulnerability of ASTs with external floating roof to extreme rainfall; more than 15 floating roofs sank or tilted due to rain water accumulation on them, releasing pollutants in the atmosphere. Secondly, recent fragility models developed by the authors are presented which allow structural vulnerability assessment of floating roofs during rainfall events and ASTs during flood events. The fragility models are then coupled with Harvey rainfall and flood empirical data to identify the conditions (i.e.: internal liquid height or density, drainage system design and efficiency, etc.) that could have led to the observed failures during Hurricane Harvey. Finally, the conditions causing tank failures are studied to propose mitigation measures to prevent future AST failures during severe storm, flood, or rainfall events.

Natural flood management in Southwell (Nottinghamshire, UK): an interdisciplinary approach in a rural-urban catchment

NASA Astrophysics Data System (ADS)

Wells, Josh; Labadz, Jillian; Islam, Mofa; Smith, Amanda; Disney, Andrew; Thorne, Colin

2017-04-01

The town of Southwell (Nottinghamshire, UK) is situated within a rural catchment and has experienced multiple flood events. In summer 2013 an extreme event occurred in which 107.6mm of rain fell within two hours, flooding up to 300 homes. As a result, a voluntary flood action group was established in the community (Southwell Flood Forum). An experimental natural flood management research project has been developed within the Potwell Dyke catchment (above Southwell). This has led to the creation of a catchment partnership of relevant stakeholders (academics, community, statutory bodies, local government and conservation organisations). Prior to intervention, water level monitoring was installed at five locations and flows were gauged for approximately one year. Rainfall data are available from the university weather station within the catchment. Ten large woody debris dams were installed on two of the streams within the catchment in summer 2016. In November, a stream restoration took place to reinstate historic meanders and create online storage in a previously ditched channel reach, together with the construction of five earth bunds in the corners of the fields. These interventions are designed to store and slow water whilst promoting ecological gains. The research takes an interdisciplinary approach. The aims are to assess the extent to which natural food management (NFM) can reduce fluvial flood occurrence but also identify and analyse current barriers to NFM uptake. Interviews with landowners in the catchment have taken place. Practitioners have also been interviewed in order to discuss the barriers to current uptake from an industry perspective. This study therefore not only addresses the evidence gap but also draws upon current barriers to advise future NFM projects. This paper will present preliminary findings from the hydrological monitoring and summarise barriers identified and lessons learned from stakeholder engagement activities.

Mental health impacts of flooding: a controlled interrupted time series analysis of prescribing data in England.

PubMed

Milojevic, Ai; Armstrong, Ben; Wilkinson, Paul

2017-10-01

There is emerging evidence that people affected by flooding suffer adverse impacts on their mental well-being, mostly based on self-reports. We examined prescription records for drugs used in the management of common mental disorder among primary care practices located in the vicinity of recent large flood events in England, 2011-2014. A controlled interrupted time series analysis was conducted of the number of prescribing items for antidepressant drugs in the year before and after the flood onset. Pre-post changes were compared by distance of the practice from the inundated boundaries among 930 practices located within 10 km of a flood. After control for deprivation and population density, there was an increase of 0.59% (95% CI 0.24 to 0.94) prescriptions in the postflood year among practices located within 1 km of a flood over and above the change observed in the furthest distance band. The increase was greater in more deprived areas. This study suggests an increase in prescribed antidepressant drugs in the year after flooding in primary care practices close to recent major floods in England. The degree to which the increase is actually concentrated in those flooded can only be determined by more detailed linkage studies. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Additional Cultural Resources Investigations at Selected Portions of the State-Road Coulee - Pammel Creek Flood Control Project at La Crosse, Wisconsin

DTIC Science & Technology

1986-05-01

Mammals: Ten mammal taxa are represented in the Lc176 assemblage. Two of these, the short-tailed shrew (Blarina brevivicauda) and a vole (Microtus sp...ADDITIONAL CULTURAL RESOURCES INVESTIGATIONS AT SELECTED PORTIONS OF THE STATE-ROAD COULEE - PAMMEL CREEK FLOOD CONTROL PROJECT ATm LA CROSSE...INVESTIGATIONS AT SELECTED PORTIONS OF THE STATE-ROAD COULEE- PAMMEL CREEK FLOOD CONTROL PROJECT AT LA CROSSE. WISCONSIN 12. PERSONAL AUTHOR(S

Regression Equations for Estimating Flood Flows at Selected Recurrence Intervals for Ungaged Streams in Pennsylvania

USGS Publications Warehouse

Roland, Mark A.; Stuckey, Marla H.

2008-01-01

Regression equations were developed for estimating flood flows at selected recurrence intervals for ungaged streams in Pennsylvania with drainage areas less than 2,000 square miles. These equations were developed utilizing peak-flow data from 322 streamflow-gaging stations within Pennsylvania and surrounding states. All stations used in the development of the equations had 10 or more years of record and included active and discontinued continuous-record as well as crest-stage partial-record stations. The state was divided into four regions, and regional regression equations were developed to estimate the 2-, 5-, 10-, 50-, 100-, and 500-year recurrence-interval flood flows. The equations were developed by means of a regression analysis that utilized basin characteristics and flow data associated with the stations. Significant explanatory variables at the 95-percent confidence level for one or more regression equations included the following basin characteristics: drainage area; mean basin elevation; and the percentages of carbonate bedrock, urban area, and storage within a basin. The regression equations can be used to predict the magnitude of flood flows for specified recurrence intervals for most streams in the state; however, they are not valid for streams with drainage areas generally greater than 2,000 square miles or with substantial regulation, diversion, or mining activity within the basin. Estimates of flood-flow magnitude and frequency for streamflow-gaging stations substantially affected by upstream regulation are also presented.

Using Pressure and Volumetric Approaches to Estimate CO2 Storage Capacity in Deep Saline Aquifers

DOE PAGES

Thibeau, Sylvain; Bachu, Stefan; Birkholzer, Jens; ...

2014-12-31

Various approaches are used to evaluate the capacity of saline aquifers to store CO 2, resulting in a wide range of capacity estimates for a given aquifer. The two approaches most used are the volumetric “open aquifer” and “closed aquifer” approaches. We present four full-scale aquifer cases, where CO 2 storage capacity is evaluated both volumetrically (with “open” and/or “closed” approaches) and through flow modeling. These examples show that the “open aquifer” CO 2 storage capacity estimation can strongly exceed the cumulative CO 2 injection from the flow model, whereas the “closed aquifer” estimates are a closer approximation to themore » flow-model derived capacity. An analogy to oil recovery mechanisms is presented, where the primary oil recovery mechanism is compared to CO 2 aquifer storage without producing formation water; and the secondary oil recovery mechanism (water flooding) is compared to CO 2 aquifer storage performed simultaneously with extraction of water for pressure maintenance. This analogy supports the finding that the “closed aquifer” approach produces a better estimate of CO 2 storage without water extraction, and highlights the need for any CO 2 storage estimate to specify whether it is intended to represent CO 2 storage capacity with or without water extraction.« less

Ecosystem ecology meets adaptive management: food web response to a controlled flood on the Colorado River, Glen Canyon

USGS Publications Warehouse

Cross, Wyatt F.; Baxter, Colden V.; Donner, Kevin C.; Rosi-Marshall, Emma J.; Kennedy, Theodore A.; Hall, Robert O.; Wellard Kelly, Holly A.; Rogers, R. Scott

2011-01-01

Large dams have been constructed on rivers to meet human demands for water, electricity, navigation, and recreation. As a consequence, flow and temperature regimes have been altered, strongly affecting river food webs and ecosystem processes. Experimental high-flow dam releases, i.e., controlled floods, have been implemented on the Colorado River, USA, in an effort to reestablish pulsed flood events, redistribute sediments, improve conditions for native fishes, and increase understanding of how dam operations affect physical and biological processes. We quantified secondary production and organic matter flows in the food web below Glen Canyon dam for two years prior and one year after an experimental controlled flood in March 2008. Invertebrate biomass and secondary production declined significantly following the flood (total biomass, 55% decline; total production, 56% decline), with most of the decline driven by reductions in two nonnative invertebrate taxa, Potamopyrgus antipodarum and Gammarus lacustris. Diatoms dominated the trophic basis of invertebrate production before and after the controlled flood, and the largest organic matter flows were from diatoms to the three most productive invertebrate taxa (P. antipodarum, G. lacustris, and Tubificida). In contrast to invertebrates, production of rainbow trout (Oncorhynchus mykiss) increased substantially (194%) following the flood, despite the large decline in total secondary production of the invertebrate assemblage. This counterintuitive result is reconciled by a post-flood increase in production and drift concentrations of select invertebrate prey (i.e., Chironomidae and Simuliidae) that supported a large proportion of trout production but had relatively low secondary production. In addition, interaction strengths, measured as species impact values, were strongest between rainbow trout and these two taxa before and after the flood, demonstrating that the dominant consumer—resource interactions were not necessarily congruent with the dominant organic matter flows. Our study illustrates the value of detailed food web analysis for elucidating pathways by which dam management may alter production and strengths of species interactions in river food webs. We suggest that controlled floods may increase production of nonnative rainbow trout, and this information can be used to help guide future dam management decisions.

Global and Regional Real-time Systems for Flood and Drought Monitoring and Prediction

NASA Astrophysics Data System (ADS)

Hong, Y.; Gourley, J. J.; Xue, X.; Flamig, Z.

2015-12-01

A Hydrometeorological Extreme Mapping and Prediction System (HyXtreme-MaP), initially built upon the Coupled Routing and Excess STorage (CREST) distributed hydrological model, is driven by real-time quasi-global TRMM/GPM satellites and by the US Multi-Radar Multi-Sensor (MRMS) radar network with dual-polarimetric upgrade to simulate streamflow, actual ET, soil moisture and other hydrologic variables at 1/8th degree resolution quasi-globally (http://eos.ou.edu) and at 250-meter 2.5-mintue resolution over the Continental United States (CONUS: http://flash.ou.edu).­ Multifaceted and collaborative by-design, this end-to-end research framework aims to not only integrate data, models, and applications but also brings people together (i.e., NOAA, NASA, University researchers, and end-users). This presentation will review the progresses, challenges and opportunities of such HyXTREME-MaP System used to monitor global floods and droughts, and also to predict flash floods over the CONUS.

Development of a model-based flood emergency management system in Yujiang River Basin, South China

NASA Astrophysics Data System (ADS)

Zeng, Yong; Cai, Yanpeng; Jia, Peng; Mao, Jiansu

2014-06-01

Flooding is the most frequent disaster in China. It affects people's lives and properties, causing considerable economic loss. Flood forecast and operation of reservoirs are important in flood emergency management. Although great progress has been achieved in flood forecast and reservoir operation through using computer, network technology, and geographic information system technology in China, the prediction accuracy of models are not satisfactory due to the unavailability of real-time monitoring data. Also, real-time flood control scenario analysis is not effective in many regions and can seldom provide online decision support function. In this research, a decision support system for real-time flood forecasting in Yujiang River Basin, South China (DSS-YRB) is introduced in this paper. This system is based on hydrological and hydraulic mathematical models. The conceptual framework and detailed components of the proposed DSS-YRB is illustrated, which employs real-time rainfall data conversion, model-driven hydrologic forecasting, model calibration, data assimilation methods, and reservoir operational scenario analysis. Multi-tiered architecture offers great flexibility, portability, reusability, and reliability. The applied case study results show the development and application of a decision support system for real-time flood forecasting and operation is beneficial for flood control.

A synthesis of recent research regarding the spring flood in Wisconsin: Knowns and unknowns

USDA-ARS?s Scientific Manuscript database

Approximately half of Wisconsin’s cranberry growers replace a spring insecticide application with a 1- to 2-day spring flood. Despite the potential for this flood to be a highly cost-effective alternative to chemical insect controls, growers need to know whether the flood can reduce pest pressure wi...

Development of Real-Time System for Urban Flooding by Surcharge of Storm Drainge and River Inundation

NASA Astrophysics Data System (ADS)

Shim, J. B.; Won, C. Y.; Park, J.; Lee, K.

2017-12-01

Korea experiences frequent flood disasters, which cause considerable economic losses and damages to towns and farms. Especially, a regional torrential storm is about 98.5mm/hr on September 21, 2010 in Seoul. The storm exceeds the capacity of urban drainage system of 75mm/hr, and 9,419 houses. How to monitor and control the urban flood disasters is an important issue in Korea. To mitigate the flood damage, a customizing system was developed to estimate urban floods and inundation using by integrating drainage system data and river information database which are managed by local governments and national agencies. In the case of Korean urban city, there are a lot of detention ponds and drainage pumping stations on end of drainage system and flow is going into river. The drainage pumping station, it is very important hydraulic facility for flood control between river and drainage system. So, it is possible to occur different patterns of flood inundation according to operation rule of drainage pumping station. A flood disaster is different damage as how to operate drainage pumping station and plan operation rule.

Responses of black willow ( Salix nigra) cuttings to simulated herbivory and flooding

NASA Astrophysics Data System (ADS)

Li, Shuwen; Martin, Lili T.; Pezeshki, S. Reza; Shields, F. Douglas

2005-09-01

Herbivory and flooding influence plant species composition and diversity in many wetland ecosystems. Black willow ( Salix nigra) naturally occurs in floodplains and riparian zones of the southeastern United States. Cuttings from this species are used as a bioengineering tool for streambank stabilization and habitat rehabilitation. The present study was conducted to evaluate the photosynthetic and growth responses of black willow to simulated herbivory and flooding. Potted cuttings were subjected to three levels of single-event herbivory: no herbivory (control), light herbivory, and heavy herbivory; and three levels of flooding conditions: no flooding (control), continuous flooding, and periodic flooding. Results indicated that elevated stomatal conductance partially contributed to the increased net photosynthesis noted under both levels of herbivory on day 30. However, chlorophyll content was not responsible for the observed compensatory photosynthesis. Cuttings subjected to heavy herbivory accumulated the lowest biomass even though they had the highest height growth by the conclusion of the experiment. In addition, a reduction in root/shoot ratio was noted for plants subjected to continuous flooding with no herbivory. However, continuously flooded, lightly clipped plants allocated more resources to roots than shoots. This study provides evidence that it is feasible to use black willow for habitat rehabilitation along highly eroded streambanks where both flooding and herbivory are present.

The Wildcat-San Pablo Creek Flood Control Project and Its Implications for the Design of Environmentally Sensitive Flood Management Plans

Treesearch

A. L. Riley

1989-01-01

In 1982 a coalition of neighborhood and environmental organizations used a community organizing strategy of the early 1960's, referred to as "advocacy planning" to substantially redesign a traditional structural type of joint federal and local flood control project on Wildcat and San Pablo Creeks in North Richmond, California. Using a combination of...

Increase in flood risk resulting from climate change in a developed urban watershed - the role of storm temporal patterns

NASA Astrophysics Data System (ADS)

Hettiarachchi, Suresh; Wasko, Conrad; Sharma, Ashish

2018-03-01

The effects of climate change are causing more frequent extreme rainfall events and an increased risk of flooding in developed areas. Quantifying this increased risk is of critical importance for the protection of life and property as well as for infrastructure planning and design. The updated National Oceanic and Atmospheric Administration (NOAA) Atlas 14 intensity-duration-frequency (IDF) relationships and temporal patterns are widely used in hydrologic and hydraulic modeling for design and planning in the United States. Current literature shows that rising temperatures as a result of climate change will result in an intensification of rainfall. These impacts are not explicitly included in the NOAA temporal patterns, which can have consequences on the design and planning of adaptation and flood mitigation measures. In addition there is a lack of detailed hydraulic modeling when assessing climate change impacts on flooding. The study presented in this paper uses a comprehensive hydrologic and hydraulic model of a fully developed urban/suburban catchment to explore two primary questions related to climate change impacts on flood risk. (1) How do climate change effects on storm temporal patterns and rainfall volumes impact flooding in a developed complex watershed? (2) Is the storm temporal pattern as critical as the total volume of rainfall when evaluating urban flood risk? We use the NOAA Atlas 14 temporal patterns, along with the expected increase in temperature for the RCP8.5 scenario for 2081-2100, to project temporal patterns and rainfall volumes to reflect future climatic change. The model results show that different rainfall patterns cause variability in flood depths during a storm event. The changes in the projected temporal patterns alone increase the risk of flood magnitude up to 35 %, with the cumulative impacts of temperature rise on temporal patterns and the storm volume increasing flood risk from 10 to 170 %. The results also show that regional storage facilities are sensitive to rainfall patterns that are loaded in the latter part of the storm duration, while extremely intense short-duration storms will cause flooding at all locations. This study shows that changes in temporal patterns will have a significant impact on urban/suburban flooding and need to be carefully considered and adjusted to account for climate change when used for the design and planning of future storm water systems.

Geomorphic adjustment to hydrologic modifications along a meandering river: Implications for surface flooding on a floodplain

NASA Astrophysics Data System (ADS)

Edwards, Brandon L.; Keim, Richard F.; Johnson, Erin L.; Hupp, Cliff R.; Marre, Saraline; King, Sammy L.

2016-09-01

Responses of large regulated rivers to contemporary changes in base level are not well understood. We used field measurements and historical analysis of air photos and topographic maps to identify geomorphic trends of the lower White River, Arkansas, USA, in the 70 years following base-level lowering at its confluence with the Mississippi River and concurrent with flood control by dams. Incision was identified below a knickpoint area upstream of St. Charles, AR, and increases over the lowermost 90 km of the study site to 2 m near the confluence with the Mississippi River. Mean bankfull width increased by 30 m (21%) from 1930 to 2010. Bank widening appears to be the result of flow regulation above the incision knickpoint and concomitant with incision below the knickpoint. Hydraulic modeling indicated that geomorphic adjustments likely reduced flooding by 58% during frequent floods in the incised, lowermost floodplain affected by backwater flooding from the Mississippi River and by 22% above the knickpoint area. Dominance of backwater flooding in the incised reach indicates that incision is more important than flood control on the lower White River in altering flooding and also suggests that the Mississippi River may be the dominant control in shaping the lower floodplain. Overall, results highlight the complex geomorphic adjustment in large river-floodplain systems in response to anthropogenic modifications and their implications, including reduced river-floodplain connectivity.

The effect of a disastrous flood on the quality of life in Dongting lake area in China.

PubMed

Tan, H Z; Luo, Y J; Wen, S W; Liu, A Z; Li, S Q; Yang, T B; Sun, Z Q

2004-01-01

We carried out an epidemiological study to assess the impact of flood on the quality of life (QOL) of residents in the affected areas in China. We used a natural experiment approach, randomly selected 494 adults from 18 villages, which suffered from flooding as a result of embankments collapsing, 473 adults from 16 villages, which suffered from, soaked flood, and 773 adults from 11 villages without flood (control group). We used the Generic QOL Inventory-74 (GQOLI-74), social support scale, and questionnaires to assess the QOL of all study participants. The QOL was significantly poorer in soaked group (58.4) and (especially) in collapsed group (55.1) than in control group (59.5, p<0.001). Adjustment for potential confounding factors did not change the results. The impact of flood on QOL was stronger among farmers, seniors, persons with introvert personality, and residents with adverse life-events, whereas social support and extrovert personalities offset the negative impact of flood on QOL.

The Impacts of Episodic Storm and Flood Events on Carbon and Sediment Delivery to Gulf of Mexico Sediments

NASA Astrophysics Data System (ADS)

Schreiner, K. M.; Carlin, J. A.; Sayers, L.; Swenson, J.

2017-12-01

Marine sediments are an important long-term reservoir for both recently fixed organic carbon (OC) and ancient rock derived OC, much of which is delivered by rivers. The ratio between these two sources of OC in turn regulates atmospheric levels of oxygen and carbon dioxide over geologic time, making this riverine delivery of OC, primarily carried by sediments, an important flux in the global carbon cycle. However, while the overall magnitude of these fluxes are relatively well known, it remains to be determined the importance of episodic events, like storms and floods, in the flux of OC from terrestrial to marine environments. Here, we present data from a 34 cm core collected from the Gulf of Mexico at a mid-shelf distal depocenter for the Brazos River in 2015, during a strong El Nino when that area of the country was experiencing 100-year flood events and anomalously high river flow. Based on analysis of the radioactive isotope 7Be, approximately the top 7-8 cm of the sediment in this core was deposited during this flood event. Both bulk elemental (C, N, and stable carbon isotopes) and chemical biomarker (lignin-phenol) data has been combined to provide information of the origin and chemistry of the OC in this core both before and during flooding. C:N and d13C indicate a mixture of marine-sourced and terrestrially-sourced OC throughout the length of the core with very little variation between the flood layer and deeper sediments. However, lignin-phenol concentrations are higher in flood-deposited sediment, indicating that this sediment is likely terrestrially-sourced. Lignin-phenol indicators of OC degradation state (Acid:Aldehyde ratios) indicate that flood sediment is fresher and less degraded than deeper sediments. Taken together, these results indicate that 1. Bulk analyses are not enough to determine OC source and the importance of flood events in OC cycling and 2. Episodic events like floods could have an oversized impact on OC storage in marine sediments.

Reservoirs in the United States

USGS Publications Warehouse

Harbeck, G. Earl

1948-01-01

Man has engaged in the control of flowing water since history began. Among his early recorded efforts were reservoirs for muncipal water-supplies constructed near ancient Jerusalem to store water which was brought there in masonry conduits. 1/  Irrigation was practiced in Egypt as early as 2000 B. C. There the "basin system" was used from ancient times until the 19th century. The land was divided , into basins of approximately 40,000 acres, separated by earthen dikes. 2/  Flood waters of the Nile generally inundated the basins through canals, many of which were built by the Pharaohs. Even then the economic consequences of a deficient annual flood were recognized. Lake Maeris, which according to Herodotus was an ancient storage reservoir, is said to have had an area of 30,000 acres. In India, the British found at the time of their occupancy of the Presidency of Madras about 50,000 reservoirs for irrigation, many believed to be of ancient construction. 3/ During the period 115-130 A. D. reservoirs were built to improve the water-supply of Athens. Much has been written concerning the elaborate collection and distribution system built to supply Rome, and parts of it remain to this day as monuments to the engineering skill employed by the Romans in solving the problem of large-scale municipal water-supplies.

Water resources management in the Ganges Basin: a comparison of three strategies for conjunctive use of groundwater and surface water

USGS Publications Warehouse

Khan, Mahfuzur R.; Voss, Clifford I.; Yu, Winston; Michael, Holly A.

2014-01-01

The most difficult water resources management challenge in the Ganges Basin is the imbalance between water demand and seasonal availability. More than 80 % of the annual flow in the Ganges River occurs during the 4-month monsoon, resulting in widespread flooding. During the rest of the year, irrigation, navigation, and ecosystems suffer because of water scarcity. Storage of monsoonal flow for utilization during the dry season is one approach to mitigating these problems. Three conjunctive use management strategies involving subsurface water storage are evaluated in this study: Ganges Water Machine (GWM), Pumping Along Canals (PAC), and Distributed Pumping and Recharge (DPR). Numerical models are used to determine the efficacy of these strategies. Results for the Indian State of Uttar Pradesh (UP) indicate that these strategies create seasonal subsurface storage from 6 to 37 % of the yearly average monsoonal flow in the Ganges exiting UP over the considered range of conditions. This has clear implications for flood reduction, and each strategy has the potential to provide irrigation water and to reduce soil waterlogging. However, GWM and PAC require significant public investment in infrastructure and management, as well as major shifts in existing water use practices; these also involve spatially-concentrated pumping, which may induce land subsidence. DPR also requires investment and management, but the distributed pumping is less costly and can be more easily implemented via adaptation of existing water use practices in the basin.

Geomorphic changes caused by the 2011 flood at selected sites along the lower Missouri River and comparison to historical floods: Chapter H in 2011 floods of the central United States

USGS Publications Warehouse

Juracek, Kyle E.

2014-01-01

An analysis of recent and historical U.S. Geological Survey streamgage information was used to assess geomorphic changes caused by the 2011 flood, in comparison to selected historical floods, at three streamgage sites along the lower Missouri River—Sioux City, Iowa; Omaha, Nebraska; and Kansas City, Missouri. Channel-width change was not evident at the three streamgage sites following the 2011 flood and likely was inhibited by bank stabilization. Pronounced changes in channel-bed elevation were indicated. At Sioux City and Omaha, the geomorphic effects of the 2011 flood were similar in terms of the magnitude of channelbed scour and recovery. At both sites, the 2011 flood caused pronounced scour (about 3 feet) of the channel bed; however, at Omaha, most of the channel-bed scour occurred after the flood had receded. More than 1 year after the flood, the channel bed had only partially recovered (about 1 foot) at both sites. Pronounced scour (about 3 feet at Sioux City and about 1.5 feet at Omaha) also was caused by the 1952 flood, which had a substantially larger peak discharge but was much shorter in duration at both sites. Again, at Omaha, most of the channel- bed scour occurred after the flood had receded. At Sioux City, substantial recovery of the channel bed (about 2.5 feet) was documented 1 year after the 1952 flood. Recovery to the pre-flood elevation was complete by April 1954. The greater recovery following the 1952 flood, compared to the 2011 flood, likely was related to a more abundant sediment supply because the flood predated the completion of most of the main-stem dam, channelization, and bank stabilization projects. At Omaha, following the 1952 flood, the channel bed never fully recovered to its pre-flood elevation. The geomorphic effect of the 2011 flood at Kansas City was fill (about 1 foot) on the channel bed followed by relative stability. The 1952 flood, which had a substantially larger peak discharge but was much shorter in duration, caused modest fill (about 0.5 foot) on the channel bed. The 1993 flood, which also had a substantially larger peak discharge but was much shorter in duration, caused pronounced scour of the channel bed (possibly as much as 4 feet). Similar to the floods at Omaha, much of the channel-bed scour at Kansas City occurred after the 1993 flood had receded. More than 1 year after the 1993 flood, following partial recovery (about 1 foot), the channel bed had stabilized, at least temporarily. Following the 1993 flood, the channel bed never fully recovered to its pre-flood elevation. For each flood in the post-dam era that resulted in substantial channel-bed scour (Sioux City in 2011, Omaha in 2011, Kansas City in 1993), recovery of the channel bed to its pre-flood elevation had not occurred more than 1 year after the flood (20 years after the 1993 flood at Kansas City). Thus, the possibility exists that channel-bed scour caused by large floods may have a cumulative effect along the lower Missouri River. The persistence of the flood-related decreases in channel-bed elevation may be indicative of the constrained ability of the channel to recover given a limited sediment supply caused by one or more of the following factors: upstream storage of sediment in reservoirs, bank stabilization, commercial sand dredging, depletion of readily available sediment by the flood, and a lack of post-flood sediment contributions from tributaries.

On the role of flood wave celerity-discharge relationship and its applications on hydrological studies

NASA Astrophysics Data System (ADS)

Fleischmann, Ayan; Collischonn, Walter; Jardim, Pedro; Meyer, Aline; Paiva, Rodrigo

2017-04-01

The non-linear relationship between flood wave celerity (C) and discharge (Q) plays an important role on defining how flood waves are routed through the river network. The behavior of this curve is driven by cross section geometry, which leads to increasing celerity with discharge in rivers without floodplains. In reaches with floodplain storage, C may decrease after bankfull Q. Thus, in a set of studies we investigate the effects of C x Q relationships on the basin hydrological response. (i) We studied these curves for several Brazilian river reaches, and analyzed to which extent they are related to river channel geometry and other characteristics (e.g., slope, width, drainage area and sinuosity). (ii) It is shown through empirical, analytical and numerical experiments how C x Q relation affects hydrograph skewness, and how the decreasing relationship existent in rivers with important floodplain storage leads to negatively skewed hydrographs, such as in the Amazon and Pantanal regions, which could be used to infer important floodplain processes (e.g., presence of overbank flow wetlands, which feature negatively skewed hydrographs or interfluvial wetlands not directly connected to rivers). (iii) Finally, we found that it is possible to use these concepts to calibrate the effective bathymetry of a hydrodynamic model by fitting the C x Q relationship using SCE-UA optimization method. Our results show how important it is to investigate the non-linear hydraulic processes occurring throughout river basins to understand the overall hydrological response, and propose new frameworks to assist such studies, including the evaluation of hydrograph skewness and estimation of hydraulic geometry.

Floods of 1952 in California. Flood of January 1952 in the south San Francisco Bay region; Snowmelt flood of 1952 in Kern River, Tulare Lake, and San Joaquin River basins

USGS Publications Warehouse

Rantz, S.E.; Stafford, H.M.

1956-01-01

Two major floods occurred in California in 1952. The first was the flood of January 11-13 in the south San Francisco Bay region that resulted from heavy rains which began on the morning of January 11 and ended about noon January 13. This flood was notable for the magnitude of the peak discharges, although these discharges were reduced by the controlling effect of reservoirs for conservation and flood-control purposes. The flood damage was thereby reduced, and no lives were lost; damage, nevertheless, amounted to about $1.400.000. The second flood was due, not to the immediate runoff of heavy rain, but to the melting of one of the largest snow packs ever recorded in the Sierra Nevada range. In the spring and summer of 1952, flood runoff occurred on all the major streams draining the Sierra Nevada. In the northern half of the Central Valley basin?the Sacramento River basin?flood volumes and maximum daily discharges were not exceptional. and flood damage was not appreciable. However, in the southern half, which is formed by the Kern River, Tulare Lake, and San Joaquin River basins, new records for snowmelt runoff were established for some streams; but for below-normal temperatures and shorter, less warm hot spells, record flood discharges would have occurred on many others. In the three basins an area of 200,000 acres. largely cropland. was inundated, and damage was estimated at $11,800,000.

Abiotic & biotic responses of the Colorado River to controlled floods at Glen Canyon Dam, Arizona, USA

USGS Publications Warehouse

Korman, Josh; Melis, Ted; Kennedy, Theodore A.

2012-01-01

Closure of Glen Canyon Dam reduced sand supply to the Colorado River in Grand Canyon National Park by about 94% while its operation has also eroded the park's sandbar habitats. Three controlled floods released from the dam since 1995 suggest that sandbars might be rebuilt and maintained, but only if repeated floods are timed to follow tributary sand deliveries below the dam. Monitoring data show that sandbars are dynamic and that their erosion after bar building is positively related with mean daily discharge and negatively related with tributary sand production after controlled floods. The March 2008 flood affected non-native rainbow trout abundance in the Lees Ferry tailwater, which supports a blue ribbon fishery. Downstream trout dispersal from the tailwater results in negative competitive interactions and predation on endangered humpback chub. Early survival rates of age-0 trout increased more than fourfold following the 2008 flood, and twofold in 2009, relative to prior years (2006-2007). Hatch-date analysis indicated that early survival rates were much higher for cohorts that emerged about 2 months after the 2008 flood relative to cohorts that emerged earlier that year. The 2009 survival data suggest that tailwater habitat improvements persisted for at least a year, but apparently decreased in 2010. Increased early survival rates for trout coincided with the increased availability of higher quality drifting food items after the 2008 flood owing to an increase in midges and black flies, preferred food items of rainbow trout. Repeated floods from the dam might sustainably rebuild and maintain sandbars if released when new tributary sand is available below the tailwater. Spring flooding might also sustain increased trout abundance and benefit the tailwater fishery, but also be a potential risk to humpback chub in Grand Canyon.

Flood Prediction for the Tam Nong District in Mekong Delta Using Hydrological Modelling and Hydrologic Remote Sensing Technique

NASA Astrophysics Data System (ADS)

Kappas, Martin; Nguyen Hong, Quang; Thanh, Nga Pham Thi; Thu, Hang Le Thi; Nguyen Vu, Giang; Degener, Jan; Rafiei Emam, Ammar

2017-04-01

There has been an increasing attention to the large trans-boundary Mekong river basin due to various problems related to water management and flood control, for instance. Vietnam Mekong delta is located at the downstream of the river basin where is affected most by this human-induced reduction in flows from the upstream. On the other hand, the flood plain of nine anastomosing channels is increasingly effected by the seawater intrusion due to sea level rising of climate change. This results in negative impacts of salinization, drought, and floods, while formerly flooding had frequently brought positive natural gain of irrigation water and alluvial aggradation. In this research, our aim is to predict flooding for the better water management adaptation and control. We applied the model HEC-SSP 2.1 to analyze flood flow frequency, two-dimensional unsteady flow calculations in HEC-RAS 5.0 for simulating a floodplain inundation. Remote sensing-based water level (Jason-2) and inundation map were used for validation and comparison with the model simulations. The results revealed a reduction of water level at all the monitoring stations, particularly in the last decade. In addition, a trend of the inundation extension gradually declined, but in some periods it remained severe due to water release from upstream reservoirs during the rainy season (October-November). We found an acceptable agreement between the HEC-RAS and remote sensing flooding maps (around 70%). Based on the flood routine analysis, we could conclude that the water level will continue lower and lead to a trend of drought and salinization harsher in the near future. Keywords: Mekong delta, flood control, inundation, water management, hydrological modelling, remote sensing

Conserving carnivorous arthropods: an example from early-season cranberry (Ericaceae) flooding

USDA-ARS?s Scientific Manuscript database

Biological control plays an important role in many IPM programs, but can be disrupted by other control strategies, including chemical and cultural controls. In commercial cranberry production, a spring flood can replace an insecticide application, providing an opportunity to study the compatibility ...

Cooper Lake and Channels, Texas.

DTIC Science & Technology

1977-04-01

maintenance. Adverse esthetic impacts of the channel and levees. Inundation of some 90 archeo- logical sites which have been tested to the extent...below the reservoir was approximately ’,0 percent complete. In June 1976, the draft environmental impact statement (EIS) was coordinated for review and...construction necessitates cutting off natural channel bends. 3. a. Environmental Impacts : (I) Reservoir. The flood storage space in the approved

Variation in flooding-induced morphological traits in natural populations of white clover (Trifolium repens) and their effects on plant performance during soil flooding

PubMed Central

Huber, Heidrun; Jacobs, Elke; Visser, Eric J. W.

2009-01-01

Background and Aims Soil flooding leads to low soil oxygen concentrations and thereby negatively affects plant growth. Differences in flooding tolerance have been explained by the variation among species in the extent to which traits related to acclimation were expressed. However, our knowledge of variation within natural species (i.e. among individual genotypes) in traits related to flooding tolerance is very limited. Such data could tell us on which traits selection might have taken place, and will take place in future. The aim of the present study was to show that variation in flooding-tolerance-related traits is present among genotypes of the same species, and that both the constitutive variation and the plastic variation in flooding-induced changes in trait expression affect the performance of genotypes during soil flooding. Methods Clones of Trifolium repens originating from a river foreland were subjected to either drained, control conditions or to soil flooding. Constitutive expression of morphological traits was recorded on control plants, and flooding-induced changes in expression were compared with these constitutive expression levels. Moreover, the effect of both constitutive and flooding-induced trait expression on plant performance was determined. Key Results Constitutive and plastic variation of several morphological traits significantly affected plant performance. Even relatively small increases in root porosity and petiole length contributed to better performance during soil flooding. High specific leaf area, by contrast, was negatively correlated with performance during flooding. Conclusions The data show that different genotypes responded differently to soil flooding, which could be linked to variation in morphological trait expression. As flooded and drained conditions exerted different selection pressures on trait expression, the optimal value for constitutive and plastic traits will depend on the frequency and duration of flooding. These data will help us understanding the mechanisms affecting short- and long-term dynamics in flooding-prone ecosystems. PMID:18713824

Improvement of high floods predictability in the Red River of the North basin using combined remote-sensed, gauge-based and assimilated precipitation data

NASA Astrophysics Data System (ADS)

Semenova, O.; Restrepo, P. J.

2011-12-01

The Red River of the North basin (USA) is considered to be under high risk of flood danger, having experienced serious flooding during the last few years. The region climate can be characterized as cold and, during winter, it exhibits continuous snowcover modified by wind redistribution. High-hazard runoff regularly occurs as a major spring snowmelt event resulting from the relatively rapid release of water from the snowpack on frozen soils. Although in summer/autumn most rainfall occurs from convective storms over small areas and does not generate dangerous floods, the pre-winter state of the soils may radically influence spring maximum flows. Large amount of artificial agricultural tiles and numerous small post-glacial depressions influencing the redistribution of runoff complicates the predictions of high floods. In such conditions any hydrological model would not be successful without proper precipitation input. In this study the simulation of runoff processes for two watersheds in the basin of the Red River of the North, USA, was undertaken using the Hydrograph model developed at the State Hydrological Institute (St. Petersburg, Russia). The Hydrograph is a robust process-based model, where the processes have a physical basis combined with some strategic conceptual simplifications that give it the ability to be applied in the conditions of low information availability. It accounts for the processes of frost and thaw of soils, snow redistribution and depression storage impacts. The assessment of the model parameters was conducted based on the characteristics of soil and vegetation cover. While performing the model runs, the parameters of depression storage and the parameters of different types of flow were manually calibrated to reproduce the observed flow. The model provided satisfactory simulation results in terms not only of river runoff but also variable sates of soil like moisture and temperature over a simulation period 2005 - 2010. For experimental runs precipitation from different sources was used as forcing data to the hydrological model: 1) data of ground meteorological stations; 2) the Snow Data Assimilation System (SNODAS) products containing several variables: snow water equivalent, snow depth, solid and liquid precipitation; 3) MAPX precipitation data which is mean areal precipitation for a watershed calculated using the radar- and gauge-based information. The results demonstrated that in the conditions of high uncertainty of model parameters combining precipitation information from different sources (the SNODAS precipitation in winter with the MAPX precipitation in summer) significantly improves the model performance and predictability of high floods.

The effects of floodplain forest restoration and logjams on flood risk and flood hydrology

NASA Astrophysics Data System (ADS)

Dixon, Simon; Sear, David A.; Sykes, Tim; Odoni, Nicholas

2015-04-01

Flooding is the most common natural catastrophe, accounting for around half of all natural disaster related deaths and causing economic losses in Europe estimated at over € 2bn per year. In addition flooding is expected to increase in magnitude and frequency with climate change, effectively shortening the return period for a given magnitude flood. Increasing the height and extent of hard engineered defences in response to increased risk is both unsustainable and undesirable. Thus alternative approaches to flood mitigation are needed such as harnessing vegetation processes to slow the passage of flood waves and increase local flood storage. However, our understanding of these effects at the catchment scale is limited. In this presentation we demonstrate the effects of two river restoration approaches upon catchment scale flood hydrology. The addition of large wood to river channels during river restoration projects is a popular method of attempting to improve physical and biological conditions in degraded river systems. Projects utilising large wood can involve the installation of engineered logjams (ELJs), the planting and enhancement of riparian forests, or a combination of both. Altering the wood loading of a channel through installation of ELJs and increasing floodplain surface complexity through encouraging mature woodland could be expected to increase the local hydraulic resistance, increasing the timing and duration of overbank events locally and therefore increasing the travel time of a flood wave through a reach. This reach-scale effect has been documented in models and the field; however the impacts of these local changes at a catchment scale remains to be illustrated. Furthermore there is limited knowledge of how changing successional stages of a restored riparian forest through time may affect its influence on hydromorphic processes. We present results of a novel paired numerical modelling study. We model changes in flood hydrology based on a 98km² catchment using OVERFLOW; a simplified hydrological model using a spatially distributed unit hydrograph approach. Restoration scenarios for the hydrological modelling are informed by the development of a new conceptual model of riparian forest succession, including quantitative estimates of deadwood inputs to the system, using a numerical forest growth model. We explore scenarios using ELJs alone as well as managed and unmanaged riparian forest restoration at scales from reach to sub-catchment. We demonstrate that changes to catchment flood hydrology with restoration are highly location dependant and downstream flood peaks can in some cases increase through synchronisation of sub-catchment flood waves. We constrain magnitude estimates for increases and decreases in flood peaks for modelled restoration scenarios and scales. Finally we analyse the potential for using riparian forest restoration as part of an integrated flood risk management strategy, including specific examples of type and extent of restoration which may prove most beneficial.

Biogeochemical and metabolic responses to the flood pulse in a semiarid floodplain

USGS Publications Warehouse

Valett, H.M.; Baker, M.A.; Morrice, J.A.; Crawford, C.S.; Molles, M.C.; Dahm, Clifford N.; Moyer, D.L.; Thibault, J.R.; Ellis, L.M.

2005-01-01

Flood pulse inundation of riparian forests alters rates of nutrient retention and organic matter processing in the aquatic ecosystems formed in the forest interior. Along the Middle Rio Grande (New Mexico, USA), impoundment and levee construction have created riparian forests that differ in their inter-flood intervals (IFIs) because some floodplains are still regularly inundated by the flood pulse (i.e., connected), while other floodplains remain isolated from flooding (i.e., disconnected). This research investigates how ecosystem responses to the flood pulse relate to forest IFI by quantifying nutrient and organic matter dynamics in the Rio Grande floodplain during three years of experimental flooding of the disconnected floodplain and during a single year of natural flooding of the connected floodplain. Surface and subsurface conditions in paired sites (control, flood) established in the two floodplain types were monitored to address metabolic and biogeochemical responses. Compared to dry controls, rates of respiration in the flooded sites increased by up to three orders of magnitude during the flood pulse. In the disconnected forest, month-long experimental floods produced widespread anoxia of four-week duration during each of the three years of flooding. In contrast, water in the connected floodplain remained well oxygenated (3-8 ppm). Material budgets for experimental floods showed the disconnected floodplain to be a sink for inorganic nitrogen and suspended solids, but a potential source of dissolved organic carbon (DOC). Compared to the main stem of the Rio Grande, flood-water on the connected floodplain contained less nitrate, but comparable concentrations of DOC, phosphate-phosphorus, and ammonium-nitrogen. Results suggest that floodplain IFI drives metabolic and biogeochemical responses during the flood pulse. Impoundment and fragmentation have altered floodplains from a mosaic of patches with variable IFI to a bimodal distribution. Relatively predictable flooding occurs in the connected forest, while inundation of the disconnected forest occurs only as the result of managed application of water. In semiarid floodplains, water is scarce except during the flood pulse. Ecosystem responses to the flood pulse are related to the IFI and other measures of flooding history that help describe spatial variation in ecosystem function.

Bathymetric survey of the Cayuga Inlet flood-control channel and selected tributaries in Ithaca, New York, 2016

USGS Publications Warehouse

Wernly, John F.; Nystrom, Elizabeth A.; Coon, William F.

2017-09-08

From July 14 to July 20, 2016, the U.S. Geological Survey, in cooperation with the City of Ithaca, New York, and the New York State Department of State, surveyed the bathymetry of the Cayuga Inlet flood-control channel and the mouths of selected tributaries to Cayuga Inlet and Cayuga Lake in Ithaca, N.Y. The flood-control channel, built by the U.S. Army Corps of Engineers between 1965 and 1970, was designed to convey flood flows from the Cayuga Inlet watershed through the City of Ithaca and minimize possible flood damages. Since that time, the channel has infrequently been maintained by dredging, and sediment accumulation and resultant shoaling have greatly decreased the conveyance of the channel and its navigational capability.U.S. Geological Survey personnel collected bathymetric data by using an acoustic Doppler current profiler. The survey produced a dense dataset of water depths that were converted to bottom elevations. These elevations were then used to generate a geographic information system bathymetric surface. The bathymetric data and resultant bathymetric surface show the current condition of the channel and provide the information that governmental agencies charged with maintaining the Cayuga Inlet for flood-control and navigational purposes need to make informed decisions regarding future maintenance measures.

An Integrated Ensemble-Based Operational Framework to Predict Urban Flooding: A Case Study of Hurricane Sandy in the Passaic and Hackensack River Basins

NASA Astrophysics Data System (ADS)

Saleh, F.; Ramaswamy, V.; Georgas, N.; Blumberg, A. F.; Wang, Y.

2016-12-01

Advances in computational resources and modeling techniques are opening the path to effectively integrate existing complex models. In the context of flood prediction, recent extreme events have demonstrated the importance of integrating components of the hydrosystem to better represent the interactions amongst different physical processes and phenomena. As such, there is a pressing need to develop holistic and cross-disciplinary modeling frameworks that effectively integrate existing models and better represent the operative dynamics. This work presents a novel Hydrologic-Hydraulic-Hydrodynamic Ensemble (H3E) flood prediction framework that operationally integrates existing predictive models representing coastal (New York Harbor Observing and Prediction System, NYHOPS), hydrologic (US Army Corps of Engineers Hydrologic Modeling System, HEC-HMS) and hydraulic (2-dimensional River Analysis System, HEC-RAS) components. The state-of-the-art framework is forced with 125 ensemble meteorological inputs from numerical weather prediction models including the Global Ensemble Forecast System, the European Centre for Medium-Range Weather Forecasts (ECMWF), the Canadian Meteorological Centre (CMC), the Short Range Ensemble Forecast (SREF) and the North American Mesoscale Forecast System (NAM). The framework produces, within a 96-hour forecast horizon, on-the-fly Google Earth flood maps that provide critical information for decision makers and emergency preparedness managers. The utility of the framework was demonstrated by retrospectively forecasting an extreme flood event, hurricane Sandy in the Passaic and Hackensack watersheds (New Jersey, USA). Hurricane Sandy caused significant damage to a number of critical facilities in this area including the New Jersey Transit's main storage and maintenance facility. The results of this work demonstrate that ensemble based frameworks provide improved flood predictions and useful information about associated uncertainties, thus improving the assessment of risks as when compared to a deterministic forecast. The work offers perspectives for short-term flood forecasts, flood mitigation strategies and best management practices for climate change scenarios.

Co-Optimization of CO 2-EOR and Storage Processes in Mature Oil Reservoirs

DOE PAGES

Ampomah, William; Balch, Robert S.; Grigg, Reid B.; ...

2016-08-02

This article presents an optimization methodology for CO 2 enhanced oil recovery in partially depleted reservoirs. A field-scale compositional reservoir flow model was developed for assessing the performance history of an active CO 2 flood and for optimizing both oil production and CO 2 storage in the Farnsworth Unit (FWU), Ochiltree County, Texas. A geological framework model constructed from geophysical, geological, and engineering data acquired from the FWU was the basis for all reservoir simulations and the optimization method. An equation of state was calibrated with laboratory fluid analyses and subsequently used to predict the thermodynamic minimum miscible pressure (MMP).more » Initial history calibrations of primary, secondary and tertiary recovery were conducted as the basis for the study. After a good match was achieved, an optimization approach consisting of a proxy or surrogate model was constructed with a polynomial response surface method (PRSM). The PRSM utilized an objective function that maximized both oil recovery and CO 2 storage. Experimental design was used to link uncertain parameters to the objective function. Control variables considered in this study included: water alternating gas cycle and ratio, production rates and bottom-hole pressure of injectors and producers. Other key parameters considered in the modeling process were CO 2 purchase, gas recycle and addition of infill wells and/or patterns. The PRSM proxy model was ‘trained’ or calibrated with a series of training simulations. This involved an iterative process until the surrogate model reached a specific validation criterion. A sensitivity analysis was first conducted to ascertain which of these control variables to retain in the surrogate model. A genetic algorithm with a mixed-integer capability optimization approach was employed to determine the optimum developmental strategy to maximize both oil recovery and CO 2 storage. The proxy model reduced the computational cost significantly. The validation criteria of the reduced order model ensured accuracy in the dynamic modeling results. The prediction outcome suggested robustness and reliability of the genetic algorithm for optimizing both oil recovery and CO 2 storage. The reservoir modeling approach used in this study illustrates an improved approach to optimizing oil production and CO 2 storage within partially depleted oil reservoirs such as FWU. Lastly, this study may serve as a benchmark for potential CO 2–EOR projects in the Anadarko basin and/or geologically similar basins throughout the world.« less

Co-Optimization of CO 2-EOR and Storage Processes in Mature Oil Reservoirs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ampomah, William; Balch, Robert S.; Grigg, Reid B.

This article presents an optimization methodology for CO 2 enhanced oil recovery in partially depleted reservoirs. A field-scale compositional reservoir flow model was developed for assessing the performance history of an active CO 2 flood and for optimizing both oil production and CO 2 storage in the Farnsworth Unit (FWU), Ochiltree County, Texas. A geological framework model constructed from geophysical, geological, and engineering data acquired from the FWU was the basis for all reservoir simulations and the optimization method. An equation of state was calibrated with laboratory fluid analyses and subsequently used to predict the thermodynamic minimum miscible pressure (MMP).more » Initial history calibrations of primary, secondary and tertiary recovery were conducted as the basis for the study. After a good match was achieved, an optimization approach consisting of a proxy or surrogate model was constructed with a polynomial response surface method (PRSM). The PRSM utilized an objective function that maximized both oil recovery and CO 2 storage. Experimental design was used to link uncertain parameters to the objective function. Control variables considered in this study included: water alternating gas cycle and ratio, production rates and bottom-hole pressure of injectors and producers. Other key parameters considered in the modeling process were CO 2 purchase, gas recycle and addition of infill wells and/or patterns. The PRSM proxy model was ‘trained’ or calibrated with a series of training simulations. This involved an iterative process until the surrogate model reached a specific validation criterion. A sensitivity analysis was first conducted to ascertain which of these control variables to retain in the surrogate model. A genetic algorithm with a mixed-integer capability optimization approach was employed to determine the optimum developmental strategy to maximize both oil recovery and CO 2 storage. The proxy model reduced the computational cost significantly. The validation criteria of the reduced order model ensured accuracy in the dynamic modeling results. The prediction outcome suggested robustness and reliability of the genetic algorithm for optimizing both oil recovery and CO 2 storage. The reservoir modeling approach used in this study illustrates an improved approach to optimizing oil production and CO 2 storage within partially depleted oil reservoirs such as FWU. Lastly, this study may serve as a benchmark for potential CO 2–EOR projects in the Anadarko basin and/or geologically similar basins throughout the world.« less

Study on reservoir time-varying design flood of inflow based on Poisson process with time-dependent parameters

NASA Astrophysics Data System (ADS)

Li, Jiqing; Huang, Jing; Li, Jianchang

2018-06-01

The time-varying design flood can make full use of the measured data, which can provide the reservoir with the basis of both flood control and operation scheduling. This paper adopts peak over threshold method for flood sampling in unit periods and Poisson process with time-dependent parameters model for simulation of reservoirs time-varying design flood. Considering the relationship between the model parameters and hypothesis, this paper presents the over-threshold intensity, the fitting degree of Poisson distribution and the design flood parameters are the time-varying design flood unit period and threshold discriminant basis, deduced Longyangxia reservoir time-varying design flood process at 9 kinds of design frequencies. The time-varying design flood of inflow is closer to the reservoir actual inflow conditions, which can be used to adjust the operating water level in flood season and make plans for resource utilization of flood in the basin.

10. VIEW OF THE SOUTH ELEVATION AND THE FLOOD GATE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

10. VIEW OF THE SOUTH ELEVATION AND THE FLOOD GATE ON THE PRESSURE CULVERT, LOOKING NORTH. - Wyoming Valley Flood Control System, Woodward Pumping Station, East of Toby Creek crossing by Erie-Lackawanna Railroad, Edwardsville, Luzerne County, PA