Modeling land use change impacts on water resources in a tropical West African catchment (Dano, Burkina Faso)

NASA Astrophysics Data System (ADS)

Yira, Y.; Diekkrüger, B.; Steup, G.; Bossa, A. Y.

2016-06-01

This study investigates the impacts of land use change on water resources in the Dano catchment, Burkina Faso, using a physically based hydrological simulation model and land use scenarios. Land use dynamic in the catchment was assessed through the analysis of four land use maps corresponding to the land use status in 1990, 2000, 2007, and 2013. A reclassification procedure levels out differences between the classification schemes of the four maps. The land use maps were used to build five land use scenarios corresponding to different levels of land use change in the catchment. Water balance was simulated by applying the Water flow and balance Simulation Model (WaSiM) using observed discharge, soil moisture, and groundwater level for model calibration and validation. Model statistical quality measures (R2, NSE and KGE) achieved during calibration and validation ranged between 0.6 and 0.9 for total discharge, soil moisture, and groundwater level, indicating a good agreement between observed and simulated variables. After a successful multivariate validation the model was applied to the land use scenarios. The land use assessment exhibited a decrease of savannah at an annual rate of 2% since 1990. Conversely, cropland and urban areas have increased. Since urban areas occupy only 3% of the catchment it can be assumed that savannah was mainly converted to cropland. The conversion rate of savannah was lower than the annual population growth of 3%. A clear increase in total discharge (+17%) and decrease in evapotranspiration (-5%) was observed following land use change in the catchment. A strong relationship was established between savannah degradation, cropland expansion, discharge increase and reduction of evapotranspiration. The increase in total discharge is related to high peak flow, suggesting (i) an increase in water resources that are not available for plant growth and human consumption and (ii) an alteration of flood risk for both the population within and

Influence of land development on stormwater runoff from a mixed land use and land cover catchment.

PubMed

Paule-Mercado, M A; Lee, B Y; Memon, S A; Umer, S R; Salim, I; Lee, C-H

2017-12-01

Mitigating for the negative impacts of stormwater runoff is becoming a concern due to increased land development. Understanding how land development influences stormwater runoff is essential for sustainably managing water resources. In recent years, aggregate low impact development-best management practices (LID-BMPs) have been implemented to reduce the negative impacts of stormwater runoff on receiving water bodies. This study used an integrated approach to determine the influence of land development and assess the ecological benefits of four aggregate LID-BMPs in stormwater runoff from a mixed land use and land cover (LULC) catchment with ongoing land development. It used data from 2011 to 2015 that monitored 41 storm events and monthly LULC, and a Personalized Computer Storm Water Management Model (PCSWMM). The four aggregate LID-BMPs are: ecological (S1), utilizing pervious covers (S2), and multi-control (S3) and (S4). These LID-BMPs were designed and distributed in the study area based on catchment characteristics, cost, and effectiveness. PCSWMM was used to simulate the monitored storm events from 2014 (calibration: R 2 and NSE>0.5; RMSE <11) and 2015 (validation: R 2 and NSE>0.5; RMSE <12). For continuous simulation and analyzing LID-BMPs scenarios, the five-year (2011 to 2015) stormwater runoff data and LULC change patterns (only 2015 for LID-BMPs) were used. Results show that the expansion of bare land and impervious cover, soil alteration, and high amount of precipitation influenced the stormwater runoff variability during different phases of land development. The four aggregate LID-BMPs reduced runoff volume (34%-61%), peak flow (6%-19%), and pollutant concentrations (53%-83%). The results of this study, in addition to supporting local LULC planning and land development activities, also could be applied to input data for empirical modeling, and designing sustainable stormwater management guidelines and monitoring strategies. Copyright © 2017 Elsevier B

Water and salt balance modelling to predict the effects of land-use changes in forested catchments. 1. Small catchment water balance model

NASA Astrophysics Data System (ADS)

Sivapalan, Murugesu; Ruprecht, John K.; Viney, Neil R.

1996-03-01

A long-term water balance model has been developed to predict the hydrological effects of land-use change (especially forest clearing) in small experimental catchments in the south-west of Western Australia. This small catchment model has been used as the building block for the development of a large catchment-scale model, and has also formed the basis for a coupled water and salt balance model, developed to predict the changes in stream salinity resulting from land-use and climate change. The application of the coupled salt and water balance model to predict stream salinities in two small experimental catchments, and the application of the large catchment-scale model to predict changes in water yield in a medium-sized catchment that is being mined for bauxite, are presented in Parts 2 and 3, respectively, of this series of papers.The small catchment model has been designed as a simple, robust, conceptually based model of the basic daily water balance fluxes in forested catchments. The responses of the catchment to rainfall and pan evaporation are conceptualized in terms of three interdependent subsurface stores A, B and F. Store A depicts a near-stream perched aquifer system; B represents a deeper, permanent groundwater system; and F is an intermediate, unsaturated infiltration store. The responses of these stores are characterized by a set of constitutive relations which involves a number of conceptual parameters. These parameters are estimated by calibration by comparing observed and predicted runoff. The model has performed very well in simulations carried out on Salmon and Wights, two small experimental catchments in the Collie River basin in south-west Western Australia. The results from the application of the model to these small catchments are presented in this paper.

Sensitivity of effective rainfall amount to land use description using GIS tool. Case of a small mediterranean catchment

NASA Astrophysics Data System (ADS)

Payraudeau, S.; Tournoud, M. G.; Cernesson, F.

Distributed modelling in hydrology assess catchment subdivision to take into account physic characteristics. In this paper, we test the effect of land use aggregation scheme on catchment hydrological response. Evolution of intra-subcatchment land use is studied using statistic and entropy methods. The SCS-CN method is used to calculate effective rainfall which is here assimilated to hydrological response. Our purpose is to determine the existence of a critical threshold-area appropriate for the application of hydrological modelling. Land use aggregation effects on effective rainfall is assessed on small mediterranean catchment. The results show that land use aggregation and land use classification type have significant effects on hydrological modelling and in particular on effective rainfall modelling.

The role of land use and soils in regulating water flow in small headwater catchments of the Andes

NASA Astrophysics Data System (ADS)

Roa-GarcíA, M. C.; Brown, S.; Schreier, H.; Lavkulich, L. M.

2011-05-01

Land use changes can have a significant impact on the terrestrial component of the water cycle. This study provides a comparison of three small headwater catchments in the Andean mountains of Colombia with different composition of land use. Several methods were used to quantify differences in the hydrological behavior of these catchments such as flow duration curves, stormflow analysis, and the linear reservoir concept. They were combined with an analysis of the characteristics of soils that contribute to understanding the aggregate catchment hydrological behavior. Andisols, which are soils formed in volcanic areas and with a large capacity to hold water, amplify differences in land use and limit the potential impact of land use management activities (conservation or restoration) on the water regulation function of catchments. Of the three studied catchments, less variability of flows was observed from the catchment with a larger percentage of area in forest, and a slower decrease of flows in the dry season was observed for the catchment with a relatively higher percentage of area in wetlands. Evidence is provided for the infiltration trade-off hypothesis for tropical environments, which states that after forest removal, soil infiltration rates are smaller and the water losses through quick flow are larger than the gains by reduced evapotranspiration; this is compatible with the results of the application of the linear reservoir concept showing a faster release of water for the least forested catchment.

Investigating the potential to reduce flood risk through catchment-based land management techniques and interventions in the River Roe catchment, Cumbria,UK

NASA Astrophysics Data System (ADS)

Pearson, Callum; Reaney, Sim; Bracken, Louise; Butler, Lucy

2015-04-01

Throughout the United Kingdom flood risk is a growing problem and a significant proportion of the population are at risk from flooding throughout the country. Across England and Wales over 5 million people are believed to be at risk from fluvial, pluvial or coastal flooding (DEFRA, 2013). Increasingly communities that have not dealt with flooding before have recently experienced significant flood events. The communities of Stockdalewath and Highbridge in the Roe catchment, a tributary of the River Eden in Cumbria, UK, are an excellent example. The River Roe has a normal flow of less than 5m3 sec-1 occurring 97 percent of the time however there have been two flash floods of 98.8m3 sec-1 in January 2005 and 86.9m3 sec-1 in May 2013. These two flash flood events resulted in the inundation of numerous properties within the catchment with the 2013 event prompting the creation of the Roe Catchment Community Water Management Group which aims are to deliver a sustainable approach to managing the flood risk. Due to the distributed rural population the community fails the cost-benefit analysis for a centrally funded flood risk mitigation scheme. Therefore the at-risk community within the Roe catchment have to look for cost-effective, sustainable techniques and interventions to reduce the potential negative impacts of future events; this has resulted in a focus on natural flood risk management. This research investigates the potential to reduce flood risk through natural catchment-based land management techniques and interventions within the Roe catchment; providing a scientific base from with further action can be enacted. These interventions include changes to land management and land use, such as soil aeration and targeted afforestation, the creation of runoff attenuation features and the construction of in channel features, such as debris dams. Natural flood management (NFM) application has been proven to be effective when reducing flood risk in smaller catchments and the

A Catchment-Based Approach to Modeling Land Surface Processes in a GCM. Part 1; Model Structure

NASA Technical Reports Server (NTRS)

Koster, Randal D.; Suarez, Max J.; Ducharne, Agnes; Stieglitz, Marc; Kumar, Praveen

2000-01-01

A new strategy for modeling the land surface component of the climate system is described. The strategy is motivated by an arguable deficiency in most state-of-the-art land surface models (LSMs), namely the disproportionately higher emphasis given to the formulation of one-dimensional, vertical physics relative to the treatment of horizontal heterogeneity in surface properties -- particularly subgrid soil moisture variability and its effects on runoff generation. The new strategy calls for the partitioning of the continental surface into a mosaic of hydrologic catchments, delineated through analysis of high-resolution surface elevation data. The effective "grid" used for the land surface is therefore not specified by the overlying atmospheric grid. Within each catchment, the variability of soil moisture is related to characteristics of the topography and to three bulk soil moisture variables through a well-established model of catchment processes. This modeled variability allows the partitioning of the catchment into several areas representing distinct hydrological regimes, wherein distinct (regime-specific) evaporation and runoff parameterizations are applied. Care is taken to ensure that the deficiencies of the catchment model in regions of little to moderate topography are minimized.

Land cover controls on summer discharge and runoff solution chemistry of semi-arid urban catchments

NASA Astrophysics Data System (ADS)

Gallo, Erika L.; Brooks, Paul D.; Lohse, Kathleen A.; McLain, Jean E. T.

2013-04-01

SummaryRecharge of urban runoff to groundwater as a stormwater management practice has gained importance in semi-arid regions where water resources are scarce and urban centers are growing. Despite this trend, the importance of land cover in controlling semi-arid catchment runoff quantity and quality remains unclear. Here we address the question: How do land cover characteristics control the amount and quality of storm runoff in semi-arid urban catchments? We monitored summertime runoff quantity and quality from five catchments dominated by distinct urban land uses: low, medium, and high density residential, mixed use, and commercial. Increasing urban land cover increased runoff duration and the likelihood that a rainfall event would result in runoff, but did not increase the time to peak discharge of episodic runoff. The effect of urban land cover on hydrologic responses was tightly coupled to the magnitude of rainfall. At distinct rainfall thresholds, roads, percent impervious cover and the stormwater drainage network controlled runoff frequency, runoff depth and runoff ratios. Contrary to initial expectations, runoff quality did not vary in repose to impervious cover or land use. We identified four major mechanisms controlling runoff quality: (1) variable solute sourcing due to land use heterogeneity and above ground catchment connectivity; (2) the spatial extent of pervious and biogeochemically active areas; (3) the efficiency of overland flow and runoff mobilization; and (4) solute flushing and dilution. Our study highlights the importance of the stormwater drainage systems characteristics in controlling urban runoff quantity and quality; and suggests that enhanced wetting and in-stream processes may control solute sourcing and retention. Finally, we suggest that the characteristics of the stormwater drainage system should be integrated into stormwater management approaches.

Simulating land use changes in the Upper Narew catchment using the RegCM model

NASA Astrophysics Data System (ADS)

Liszewska, Malgorzata; Osuch, Marzena; Romanowicz, Renata

2010-05-01

Catchment hydrology is influenced by climate forcing in the form of precipitation, temperature, evapotranspiration and human interactions such as land use and water management practices. The difficulty in separating different causes of change in a hydrological regime results from the complexity of interactions between those three factors and catchment responses and the uncertainty and scarcity of available observations. This paper describes an application of a regional climate model to simulate the variability in precipitation, temperature, evaporation and discharge under different land use parameterizations, using the Upper Narew catchment (north-east Poland) as a case study. We use RegCM3 model, developed at the International Centre for Theoretical Physics, Trieste, Italy. The model's dynamic core is based on the hydrostatic version of the NCAR/PSU Mesoscale Model version 5 (primitive equations, hydrostatic, compressible, sigma-vertical coordinate). The physical input includes radiation transfer, large-scale and convective precipitation, Planetary Boundary Layer, biosphere. The RegCM3 model has options to interface with a variety of re-analyses and GCM boundary conditions, and can thus be used for scenario assessments. The variability of hydrological conditions in response to regional climate model projections is modeled using an integrated Data Based Mechanistic (DBM) rainfall-flow/flow-routing model of the Upper River Narew catchment. The modelling tool developed is formulated in the MATLAB-SIMULINK language. The basic system structure includes rainfall-flow and flow routing modules, based on a Stochastic Transfer Function (STF) approach combined with a nonlinear transformation of rainfall into effective rainfall. We analyse the signal resulting from modified land use in a given region. 10 month-long runs have been performed from February to November for the period of 1991-2000 based on the NCEP re-analyses. The land use data have been taken from the GLCC

Sediment budgets of mountain catchments: Scale dependence and the influence of land-use

NASA Astrophysics Data System (ADS)

Förster, Helga; Dotterweich, Markus; Wunderlich, Jürgen

2010-05-01

Long-term sediment budgets of forested mountain catchments are scarcely investigated today. This is because they are traditionally expected to show few erosion features and low sediment delivery. This opinion originates from process-based hydrological studies proving the runoff preventing properties of trees and forest soils. In addition mountain areas have been colonized later and only sporadically compared to the fruitful loess-covered lowlands. On the other hand steep hillslopes, narrow valleys and the availability of regolith cause a high erosion potential. And there is evidence that historical floods and yearly occurring storms initiate intensive but local and sporadic erosion events. Sediment budgets from zero-order catchments of the Palatinate Forest in the south-western sandstone escarpment in Rhineland-Palatinate show spatially varying intensities of land use impact and relief conditions. The budgets are based on field data and a soilscape model of an upper periglacial cover bed with a homogenous thickness. OSL- and 14C-dates of colluvial deposits allow relating erosion events to land-use changes derived from historical maps and written archives. The presented case studies from the Palatinate Forest are of special interest as the high proximity to the loess-covered and intensively cultivated Rhine Graben effected settlement and land-use intensity in the mountain catchments. Clear cuts for settlements were joined by deforestation for agriculture and stretched mainly along the Haardtrand and high order valleys. Off these areas the strength of interference in the forest ecosystem depended on transport possibilities and distance to the Rhine Graben. In the vicinity strong devastation and clear cutting occurred. With increasing distance the felling intensity decreased and some parts seem to be nearly undisturbed until the 18th century. The needs for wood were controlled by the economical development as well as political decisions on local to European scale. The

A 125 year long record of DOC flux from a major temperate catchment: land-use vs. climate control?

NASA Astrophysics Data System (ADS)

Clay, G.; Worrall, F.; Howden, N. K.; Burt, T. P.

2010-12-01

Our understanding of the controls upon carbon biogeochemistry has always been limited by lack of long term observational data at the same time as having long term monitoring of possible environmental drivers. For the River Thames catchment in the UK (9998 km2) records of DOM have been kept since 1868 and DOM flux since 1882. In addition to riverflow being monitored in the catchment there has also been monitoring of climate, land-use and population back to at least 1868. The Thames catchment is a mixed agricultural urban catchment dominated by mineral soils where groundwater plays a significant part in the catchments flow system. During the period of the record the catchment has undergone urbanisation, climate warming but has also undergone large-scale land use change associated with World War II and agricultural intensification in the 1960s. The importance of these combinations of pressures are explored in the time series through a range of time series techniques and the results show: i) That DOC flux in the catchment is now at historic low levels, with the maximum flux being 35 ktonnes C/yr (3.5 tonnes/km2/yr) in 1915 and the lowest flux being 2 ktonnes C/yr (0.2 tonnes/km2/yr) in 1997. ii) The trend in the DOC flux is explained by changes in flow, which appear associated with both with groundwater storage in the catchment and with changes in land-use. iii) The significant decline in the DOC flux appears to be due to the transition in the catchment from dominated from pasture to an arable land use. iv) The decline of DOC flux with temperature would suggest that DOC mineralisation reaction has a higher Q10 than the DOC production. v) Declining DOC flux from mineral soils catchments would offset increases in DOC flux from organic soils but would also represent a shift in carbon losses from fluvial to being direct to the atmosphere.

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.

Catchment hydro-biogeochemical response to climate change and future land-use

EPA Science Inventory

The potential interacting effects of climate change and future land-use on hydrological and biogeochemical dynamics rarely have been described at the catchment level and are difficult or impossible to capture through experimentation or observation alone. We apply a new model, Vi...

Integrated assessment of land use and cover changes in the Malagarasi river catchment in Tanzania

NASA Astrophysics Data System (ADS)

Kashaigili, J. J.; Majaliwa, A. M.

Malagarasi river catchment represents one of the largest and most significant transboundary natural ecosystems in Africa. The catchment constitutes about one third of the catchment area of Lake Tanganyika and contains ecosystems of both national and international importance (i.e. Muyovozi Wetland Ramsar site). It has been increasingly said that increased anthropogenic activities have had negative impacts on the Muyovozi wetland in particular and other catchment resources. Nevertheless, these beliefs are little supported by quantitative data. A study on the dynamics of land use and cover in the Malagarasi river catchment therefore investigated long-term and seasonal changes that have occurred as a result of human activities in the area for the periods between 1984 and 2001. Landsat TM and ETM+ images were used to locate and quantify the changes. Perceptions of local people on historical changes and drivers for the changes were also collected and integrated in the assessment. The study revealed a significant change in land use and cover within a period of 18 year. Between 1984 and 2001, the woodland and wetland vegetation covers declined by 0.09% and 2.51% per year. Areas with settlements and cultivation increased by 1.05% annually while bushed grassland increased at 1.93% annually. The perceived principal drivers for the changes were found to include fire, cultivation along rivers and lake shores, overgrazing, poor law enforcement, insufficient knowledge on environmental issues, increasing poverty, deforestation and population growth. The human population growth rate stands at 4.8% against a national figure of 2.9%. The most perceived environmental problems include drying of streams and rivers, change in rainfall, loss of soil fertility, soil erosion and reduced crop yield. The study concludes that, there has been significant changes in land use and cover in the catchment and these require concerted actions to reverse the changes. The study highlights the importance

Regionalization of land-use impacts on streamflow using a network of paired catchments

NASA Astrophysics Data System (ADS)

Ochoa-Tocachi, Boris F.; Buytaert, Wouter; De Bièvre, Bert

2016-09-01

Quantifying the impact of land use and cover (LUC) change on catchment hydrological response is essential for land-use planning and management. Yet hydrologists are often not able to present consistent and reliable evidence to support such decision-making. The issue tends to be twofold: a scarcity of relevant observations, and the difficulty of regionalizing any existing observations. This study explores the potential of a paired catchment monitoring network to provide statistically robust, regionalized predictions of LUC change impact in an environment of high hydrological variability. We test the importance of LUC variables to explain hydrological responses and to improve regionalized predictions using 24 catchments distributed along the Tropical Andes. For this, we calculate first 50 physical catchment properties, and then select a subset based on correlation analysis. The reduced set is subsequently used to regionalize a selection of hydrological indices using multiple linear regression. Contrary to earlier studies, we find that incorporating LUC variables in the regional model structures increases significantly regression performance and predictive capacity for 66% of the indices. For the runoff ratio, baseflow index, and slope of the flow duration curve, the mean absolute error reduces by 53% and the variance of the residuals by 79%, on average. We attribute the explanatory capacity of LUC in the regional model to the pairwise monitoring setup, which increases the contrast of the land-use signal in the data set. As such, it may be a useful strategy to optimize data collection to support watershed management practices and improve decision-making in data-scarce regions.

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

Runoff production in a small agricultural catchment in Lao PDR : influence of slope, land-use and observation scale.

NASA Astrophysics Data System (ADS)

Patin, J.; Ribolzi, O.; Mugler, C.; Valentin, C.; Mouche, E.

2009-04-01

We study the surface and sub-surface hydrology of a small agricultural catchment (60ha) located in the Luang Prabang province of Lao PDR. This catchment is representative of the rural mountainous south east Asia. It exhibits steep slopes (up to 100% and more) under a monsoon climate. After years of traditional slash and burn cultures, it is now under high land pressures due to population resettling and environment preservation policies. This evolution leads to rapid land-use changes such as shifting cultivation reduction or growing of teak forest instead of classical crops. This catchment is a benchmark site of the Managing Soil Erosion Consortium since 1998. The international consortium aims to understand the effects of agricultural changes on the catchment hydrology and soil erosion in south east Asia. The Huay Pano catchment is subdivided into small sub-catchments that are gauged and monitored. Differ- ent agricultural practices where tested along the years. At a smaller scale, plot of 1m2 are instrumented to follow runoff and detachment of soil under natural rainfall along the monsoon season. Our modeling work aims to develop a distributed hydrological model integrating experimental data at the different scales. One of the objective is to understand the impact of land-use, soil properties (slope, crust, etc) and rainfall (dry and wet seasons) on surface and subsurface flows. We present here modeling results of the runoff plot experiments (1m2 scale) performed from 2002 to 2007. The plots distribution among the catchment and over the years gives a good representativity of the different runoff responses. The role of crust, slope and land-use on runoff is examined. Finally we discuss how this plot scale will be integrated in a sub-catchment model, with a particular attention on the observed paradox: how to explain that runoff coefficients at the catchment scale are much slower than at the plot scale ?

NASA Land Cover and Land Use Change (LCLUC): an interdisciplinary research program.

PubMed

Justice, Chris; Gutman, Garik; Vadrevu, Krishna Prasad

2015-01-15

Understanding Land Cover/Land Use Change (LCLUC) in diverse regions of the world and at varied spatial scales is one of the important challenges in global change research. In this article, we provide a brief overview of the NASA LCLUC program, its focus areas, and the importance of satellite remote sensing observations in LCLUC research including future directions. The LCLUC Program was designed to be a cross-cutting theme within NASA's Earth Science program. The program aims to develop and use remote sensing technologies to improve understanding of human interactions with the environment. Since 1997, the NASA LCLUC program has supported nearly 280 research projects on diverse topics such as forest loss and carbon, urban expansion, land abandonment, wetland loss, agricultural land use change and land use change in mountain systems. The NASA LCLUC program emphasizes studies where land-use changes are rapid or where there are significant regional or global LCLUC implications. Over a period of years, the LCLUC program has contributed to large regional science programs such as Land Biosphere-Atmosphere (LBA), the Northern Eurasia Earth Science Partnership Initiative (NEESPI), and the Monsoon Area Integrated Regional Study (MAIRS). The primary emphasis of the program will remain on using remote sensing datasets for LCLUC research. The program will continue to emphasize integration of physical and social sciences to address regional to global scale issues of LCLUC for the benefit of society. Copyright © 2014. Published by Elsevier Ltd.

Development of a large-sample catchment-scale hydro-meteorological, land cover and physical dataset for Chile

NASA Astrophysics Data System (ADS)

Alvarez-Garreton, C. D.; Mendoza, P. A.; Zambrano-Bigiarini, M.; Galleguillos, M. H.; Boisier, J. P.; Lara, A.; Cortés, G.; Garreaud, R.; McPhee, J. P.; Addor, N.; Puelma, C.

2017-12-01

We provide the first catchment-based hydrometeorological, vegetation and physical data set over 531 catchments in Chile (17.8 S - 55.0 S). We compiled publicly available streamflow records at daily time steps for the period 1980-2015, and generated basin-averaged time series of the following hydrometeorological variables: 1) daily precipitation coming from three different gridded sources (re-analysis and satellite-based); 2) daily maximum and minimum temperature; 3) 8-days potential evapotranspiration (PET) based on MODIS imagery and daily PET based on Hargreaves formula; and 4) daily snow water equivalent. Additionally, catchments are characterized by their main physical (area, mean elevation, mean slope) and land cover characteristics. We synthetized these datasets with several indices characterizing the spatial distribution of climatic, hydrological, topographic and vegetation attributes. The new catchment-based dataset is unprecedented in the region and provides information that can be used in a myriad of applications, including catchment classification and regionalization studies, impacts of different land cover types on catchment response, characterization of drought history and projections, climate change impacts on hydrological processes, etc. Derived practical applications include water management and allocation strategies, decision making and adaptation planning to climate change. This data set will be publicly available and we encourage the community to use it.

[Nitrogen Losses Under the Action of Different Land Use Types of Small Catchment in Three Gorges Region].

PubMed

Chen, Cheng-long; Gao, Ming; Ni, Jiu-pai; Xie, De-ti; Deng, Hua

2016-05-15

As an independent water-collecting area, small catchment is the source of non-point source pollution in Three Gorges Region. Choosing 3 kinds of the most representative land-use types and using them to lay monitoring points of overland runoff within the small catchment of Wangjiagou in Fuling of Three Gorges Region, the author used the samples of surface runoff collected through the twelve natural rainfalls from May to December to analyze the feature of spatial-temporal change of Nitrogen's losses concentrations under the influence of different land use types and the hillslopes and small catchments composed by those land use types, revealing the relation between different land-use types and Nitrogen's losses of small catchments in Three Gorges Region. The result showed: the average losses concentration of TN showed the biggest difference for different land use types during the period of spring crops, and the average value of dry land was 1. 61 times and 6.73 times of the values of interplanting field of mulberry and paddy field, respectively; the change of the losses concentration of TN was most conspicuous in the 3 periods of paddy field. The main element was NO₃⁻-N, and the relation between TN and NO₃⁻-N showed a significant linear correlation. TN's and NO₃⁻-N's losses concentrations were significantly and positively correlated with the area ratio of corn and mustard, but got a significant negative correlation with the area ratio of paddy and mulberry; NH₄⁺-N's losses concentrations got a significant positive correlation with the area ratio of mustard. Among all the hillslopes composed by different land use types, TN's average losses concentration of surface runoff of the hillslope composed by interplantating field of mulberry and paddy land during the three periods was the lowest, and the values were 2.55, 11.52, 8.58 mg · L⁻¹, respectively; the hillslope of rotation plough land of corn and mustard had the maximum value, and the values were

Suspended sediment export in five intensive agricultural river catchments with contrasting land use and soil drainage characteristics

NASA Astrophysics Data System (ADS)

Sherriff, Sophie; Rowan, John; Melland, Alice; Jordan, Phil; Fenton, Owen; hUallacháin, Daire Ó.

2015-04-01

Soil erosion and sediment loss from land can have a negative impact on the chemical and ecological quality of freshwater resources. In catchments dominated by agriculture, prediction of soil erosion risk is complex due to the interaction of physical characteristics such as topography, soil erodibility, hydrological connectivity and climate. Robust measurement approaches facilitate the assessment of sediment loss magnitudes in relation to a range of agricultural settings. These approaches improve our understanding of critical sediment transfer periods and inform development of evidence-based and cost-effective management strategies. The aim of this study was to i) assess the efficacy of out-of-channel (ex-situ) suspended sediment measurement approaches, ii) to quantify the variability of sediment exported from five river catchments with varying hydrology and agricultural land uses over multiple years and iii) to investigate trends in relation to physical and land use characteristics when sediment data were compared between catchments. Sediment data were collected in five intensive agricultural river catchments in Ireland (3-11 km2) which featured contrasting land uses (predominantly intensive grassland or arable) and soil drainage classes (well, moderate and poor). High-resolution suspended sediment concentration data (SSC - using a calibrated turbidity proxy) were collected ex-situ and combined with in-stream discharge data measured at each catchment outlet to estimate suspended sediment yield (SSY - t km-2 yr-1). In two catchments additional in-stream turbidity monitoring equipment replicated ex-situ measurements including site specific calibration of individual in-stream and ex-situ turbidity probes. Depth-integrated samples were collected to assess the accuracy of both approaches. Method comparison results showed that true SSC values (from depth-integrated sampling) were predominantly within the 95% confidence interval of ex-situ predicted SSC consequently

Effects of land cover change on evapotranspiration and streamflow of small catchments in the Upper Xingu River Basin, Central Brazi

NASA Astrophysics Data System (ADS)

Costa, M. H.; Dias, L. C. P.; Macedo, M.; Coe, M. T.; Neill, C.

2014-12-01

This study assess the influence of land cover changes on evapotranspiration and streamflow in small catchments in the Upper Xingu River Basin (Mato Grosso state, Brazil). Streamflow was measured in catchments with uniform land use for September 1, 2008 to August 31, 2010. We used models to simulate evapotranspiration and streamflow for the four most common land cover types found in the Upper Xingu: tropical forest, cerrado (savanna), pasture, and soybean croplands. We used INLAND to perform single point simulations considering tropical rainforest, cerrado and pasturelands, and AgroIBIS for croplands. Converting natural vegetation to agriculture substantially modifies evapotranspiration and streamflow in small catchments. Measured mean streamflow in soy catchments was about three times greater than that of forest catchments, while the mean annual amplitude of flow in soy catchments was more than twice that of forest catchments. Simulated mean annual evapotranspiration was 39% lower in agricultural ecosystems (pasture and soybean cropland) than in natural ecosystems (tropical rainforest and cerrado). Observed and simulated mean annual streamflows in agricultural ecosystems were more than 100% higher than in natural ecosystems. The accuracy of the simulations is improved by using field-measured soil hydraulic properties. The inclusion of local measurements of key soil parameters is likely to improve hydrological simulations in other tropical regions.

Effects of land cover change on evapotranspiration and streamflow of small catchments in the Upper Xingu River Basin, Central Brazi

NASA Astrophysics Data System (ADS)

Costa, M. H.; Dias, L. C. P.; Macedo, M.; Coe, M. T.; Neill, C.

2015-12-01

This study assess the influence of land cover changes on evapotranspiration and streamflow in small catchments in the Upper Xingu River Basin (Mato Grosso state, Brazil). Streamflow was measured in catchments with uniform land use for September 1, 2008 to August 31, 2010. We used models to simulate evapotranspiration and streamflow for the four most common land cover types found in the Upper Xingu: tropical forest, cerrado (savanna), pasture, and soybean croplands. We used INLAND to perform single point simulations considering tropical rainforest, cerrado and pasturelands, and AgroIBIS for croplands. Converting natural vegetation to agriculture substantially modifies evapotranspiration and streamflow in small catchments. Measured mean streamflow in soy catchments was about three times greater than that of forest catchments, while the mean annual amplitude of flow in soy catchments was more than twice that of forest catchments. Simulated mean annual evapotranspiration was 39% lower in agricultural ecosystems (pasture and soybean cropland) than in natural ecosystems (tropical rainforest and cerrado). Observed and simulated mean annual streamflows in agricultural ecosystems were more than 100% higher than in natural ecosystems. The accuracy of the simulations is improved by using field-measured soil hydraulic properties. The inclusion of local measurements of key soil parameters is likely to improve hydrological simulations in other tropical regions.

Impacts of climate and land use changes on the hydrological and erosive response of a humid and dry Mediterranean catchment

NASA Astrophysics Data System (ADS)

Serpa, Dalila; Nunes, João Pedro; Santos, Juliana; Sampaio, Elsa; Jacinto, Rita; Veiga, Sandro; Lima, Júlio; Moreira, Madalena; Corte-Real, João; Keizer, Jan Jacob; Abrantes, Nelson

2016-04-01

The impacts of climate and land use changes on streamflow and sediment export were evaluated for a humid (São Lourenço) and a dry (Guadalupe) Mediterranean catchment, using the Soil and Water Assessment Tool (SWAT) model. SWAT was able to produce viable streamflow and sediment export simulations for both catchments, which provided a baseline for investigating climate and land use changes under the A1B and B1 emission scenarios for the period between 2071 and 2100. Compared to the baseline period (1971-2000), climate change scenarios forecasted a decrease in annual precipitation in both catchments (humid, both scenarios: -12%; dry, both scenarios: -8%), but with strong increases during winter. Land use changes followed a socio-economic storyline in which traditional agriculture was replaced by more profitable land uses, i.e. corn and commercial forestry at the humid site and sunflower at the dry site. Climate changes led to a decrease of streamflow in both catchments (humid, both scenarios: -13%; dry, A1B: -14%; B1: -18%), mostly as a consequence of the projected decrease in rainfall. Land use changes led to small increases in flow discharge, but a higher increase was observed for the dry site under scenario A1B (humid, A1B: +0.3%; B1: +1%; dry, A1B: +6%; B1: +0.3%). The combination of climate and land use scenarios was mostly dominated by the climatic response, since a decrease in streamflow was observed for both catchments (humid, A1B: -13%; B1: -12%; dry, A1B: -8%; B1: -18%). Regarding the erosive response, clear differences were observed between catchments mostly due to differences in both the present-day and forecasted vegetation types. Climate scenarios led to a decrease in sediment export at the humid catchment (A1B: -11%; B1: -9%) and to an increase at the dry catchment (A1B: +24%; B1: +22%) in the first case due to the predominant vegetation type (vineyards and maritime pine) providing year-round cover, while in the second, due to annual crops (wheat and

Summary of NASA landing-gear research

NASA Technical Reports Server (NTRS)

Fisher, B. D.; Sleeper, R. K.; Stubbs, S. M.

1978-01-01

This paper presents a brief summary of the airplane landing gear research underway at NASA. The technology areas include: ground handling simulator, antiskid braking systems, space shuttle nose-gear shimmy, active control landing gear, wire brush skid landing gear, air cushion landing systems, tire/surface friction characteristics, tire mechanical properties, tire-tread materials, powered wheels for taxiing, and crosswind landing gear. This paper deals mainly with the programs on tire-tread materials, powered wheel taxiing, air cushion landing systems, and crosswind landing gear research with particular emphasis on previously unreported results of recently completed flight tests. Work in the remaining areas is only mentioned.

Effects of distributed and centralized stormwater best management practices and land cover on urban stream hydrology at the catchment scale

NASA Astrophysics Data System (ADS)

Loperfido, J. V.; Noe, Gregory B.; Jarnagin, S. Taylor; Hogan, Dianna M.

2014-11-01

Urban stormwater runoff remains an important issue that causes local and regional-scale water quantity and quality issues. Stormwater best management practices (BMPs) have been widely used to mitigate runoff issues, traditionally in a centralized manner; however, problems associated with urban hydrology have remained. An emerging trend is implementation of BMPs in a distributed manner (multi-BMP treatment trains located on the landscape and integrated with urban design), but little catchment-scale performance of these systems have been reported to date. Here, stream hydrologic data (March, 2011-September, 2012) are evaluated in four catchments located in the Chesapeake Bay watershed: one utilizing distributed stormwater BMPs, two utilizing centralized stormwater BMPs, and a forested catchment serving as a reference. Among urban catchments with similar land cover, geology and BMP design standards (i.e. 100-year event), but contrasting placement of stormwater BMPs, distributed BMPs resulted in: significantly greater estimated baseflow, a higher minimum precipitation threshold for stream response and maximum discharge increases, better maximum discharge control for small precipitation events, and reduced runoff volume during an extreme (1000-year) precipitation event compared to centralized BMPs. For all catchments, greater forest land cover and less impervious cover appeared to be more important drivers than stormwater BMP spatial pattern, and caused lower total, stormflow, and baseflow runoff volume; lower maximum discharge during typical precipitation events; and lower runoff volume during an extreme precipitation event. Analysis of hydrologic field data in this study suggests that both the spatial distribution of stormwater BMPs and land cover are important for management of urban stormwater runoff. In particular, catchment-wide application of distributed BMPs improved stream hydrology compared to centralized BMPs, but not enough to fully replicate forested

Effects of distributed and centralized stormwater best management practices and land cover on urban stream hydrology at the catchment scale

USGS Publications Warehouse

Loperfido, John V.; Noe, Gregory B.; Jarnagin, S. Taylor; Hogan, Dianna M.

2014-01-01

Urban stormwater runoff remains an important issue that causes local and regional-scale water quantity and quality issues. Stormwater best management practices (BMPs) have been widely used to mitigate runoff issues, traditionally in a centralized manner; however, problems associated with urban hydrology have remained. An emerging trend is implementation of BMPs in a distributed manner (multi-BMP treatment trains located on the landscape and integrated with urban design), but little catchment-scale performance of these systems have been reported to date. Here, stream hydrologic data (March, 2011–September, 2012) are evaluated in four catchments located in the Chesapeake Bay watershed: one utilizing distributed stormwater BMPs, two utilizing centralized stormwater BMPs, and a forested catchment serving as a reference. Among urban catchments with similar land cover, geology and BMP design standards (i.e. 100-year event), but contrasting placement of stormwater BMPs, distributed BMPs resulted in: significantly greater estimated baseflow, a higher minimum precipitation threshold for stream response and maximum discharge increases, better maximum discharge control for small precipitation events, and reduced runoff volume during an extreme (1000-year) precipitation event compared to centralized BMPs. For all catchments, greater forest land cover and less impervious cover appeared to be more important drivers than stormwater BMP spatial pattern, and caused lower total, stormflow, and baseflow runoff volume; lower maximum discharge during typical precipitation events; and lower runoff volume during an extreme precipitation event. Analysis of hydrologic field data in this study suggests that both the spatial distribution of stormwater BMPs and land cover are important for management of urban stormwater runoff. In particular, catchment-wide application of distributed BMPs improved stream hydrology compared to centralized BMPs, but not enough to fully replicate forested

Attributes for MRB_E2RF1 Catchments by Major River Basins in the Conterminous United States: NLCD 2001 Land Use and Land Cover

USGS Publications Warehouse

Wieczorek, Michael; LaMotte, Andrew E.

2010-01-01

This tabular data set represents the estimated area of land use and land cover from the National Land Cover Dataset 2001 (LaMotte, 2008), compiled for every MRB_E2RF1 catchment of the Major River Basins (MRBs, Crawford and others, 2006). The source data set represents land use and land cover for the conterminous United States for 2001. The National Land Cover Data Set for 2001 was produced through a cooperative project conducted by the Multi-Resolution Land Characteristics (MRLC) Consortium. The MRLC Consortium is a partnership of Federal agencies (http://www.mrlc.gov), consisting of the U.S. Geological Survey (USGS), the National Oceanic and Atmospheric Administration (NOAA), the U.S. Environmental Protection Agency (USEPA), the U.S. Department of Agriculture (USDA), the U.S. Forest Service (USFS), the National Park Service (NPS), the U.S. Fish and Wildlife Service (USFWS), the Bureau of Land Management (BLM), and the USDA Natural Resources Conservation Service (NRCS). The MRB_E2RF1 catchments are based on a modified version of the U.S. Environmental Protection Agency's (USEPA) ERF1_2 and include enhancements to support national and regional-scale surface-water quality modeling (Nolan and others, 2002; Brakebill and others, 2011). Data were compiled for every MRB_E2RF1 catchment for the conterminous United States covering the South Atlantic-Gulf and Tennessee (MRB2), the Great Lakes, Ohio, Upper Mississippi, and Souris-Red-Rainy (MRB3), the Missouri (MRB4), the Lower Mississippi, Arkansas-White-Red, and Texas-Gulf (MRB5) and the Pacific Northwest (MRB7) river basins.

Impacts of climate and land use changes on regional nutrient export in the South Saskatchewan River catchment

NASA Astrophysics Data System (ADS)

Morales-Marin, L. A.; Wheater, H. S.; Lindenschmidt, K. E.

2016-12-01

Climate and land use changes modify the physical functioning of river catchments and, in particular, influence the transport of nutrients from land to water. In large-scale catchments, where a variety of climates, topographies, soil types and land uses co-exist to form a highly heterogeneous environment, a more complex nutrient dynamic is imposed by climate and land use changes. This is the case of the South Saskatchewan River (SSR) that, along with the North Saskatchewan River, forms the largest river system in western Canada. In the past years changes in the land use and new industrial developments in the SSR area have heightened serious concerns about the future of water quality in the catchment and downstream waters. Agricultural activities have increased the supply of manure and fertilizer for cropping. Oil and gas exploitation has also increased the risk of surface water and groundwater contamination. The rapid population growth not only leads to increments in water consumption and wastewater, but in the construction of roads, railways and the expansion of new urban developments that impose hydraulic controls on the catchment hydrology and therefore the sediment and nutrient transport. Consequences of the actual anthropogenic changes have been notorious in reservoirs where algal blooms and signs of eutrophication have become common during certain times of the year. Although environmental agencies are constantly improving the mechanisms to reduce nutrient export into the river and ensure safe water quality standards, further research is needed in order to identify major nutrient sources and quantify nutrient export and also, to assess how nutrients are going to vary as a result of future climate and land use change scenarios. The SPAtially Referenced Regression On Watershed (SPARROW) model is therefore implemented to assess water quality regionally, in order to describe spatial and temporal patterns to identify those factors and processes that affect water

Impacts of climate and land use changes on regional nutrient export in the South Saskatchewan River catchment

NASA Astrophysics Data System (ADS)

Morales-Marin, L. A.; Wheater, H. S.; Lindenschmidt, K. E.

2015-12-01

Climate and land use changes modify the physical functioning of river catchments and, in particular, influence the transport of nutrients from land to water. In large-scale catchments, where a variety of climates, topographies, soil types and land uses co-exist to form a highly heterogeneous environment, a more complex nutrient dynamic is imposed by climate and land use changes. This is the case of the South Saskatchewan River (SSR) that, along with the North Saskatchewan River, forms the largest river system in western Canada. In the past years changes in the land use and new industrial developments in the SSR area have heightened serious concerns about the future of water quality in the catchment and downstream waters. Agricultural activities have increased the supply of manure and fertilizer for cropping. Oil and gas exploitation has also increased the risk of surface water and groundwater contamination. The rapid population growth not only leads to increments in water consumption and wastewater, but in the construction of roads, railways and the expansion of new urban developments that impose hydraulic controls on the catchment hydrology and therefore the sediment and nutrient transport. Consequences of the actual anthropogenic changes have been notorious in reservoirs where algal blooms and signs of eutrophication have become common during certain times of the year. Although environmental agencies are constantly improving the mechanisms to reduce nutrient export into the river and ensure safe water quality standards, further research is needed in order to identify major nutrient sources and quantify nutrient export and also, to assess how nutrients are going to vary as a result of future climate and land use change scenarios. The SPAtially Referenced Regression On Watershed (SPARROW) model is therefore implemented to assess water quality regionally, in order to describe spatial and temporal patterns to identify those factors and processes that affect water

Future climate and land uses effects on flow and nutrient loads of a Mediterranean catchment in South Australia.

PubMed

Shrestha, Manoj K; Recknagel, Friedrich; Frizenschaf, Jacqueline; Meyer, Wayne

2017-07-15

Mediterranean catchments experience already high seasonal variability alternating between dry and wet periods, and are more vulnerable to future climate and land use changes. Quantification of catchment response under future changes is particularly crucial for better water resources management. This study assessed the combined effects of future climate and land use changes on water yield, total nitrogen (TN) and total phosphorus (TP) loads of the Mediterranean Onkaparinga catchment in South Australia by means of the eco-hydrological model SWAT. Six different global climate models (GCMs) under two representative concentration pathways (RCPs) and a hypothetical land use change were used for future simulations. The climate models suggested a high degree of uncertainty, varying seasonally, in both flow and nutrient loads; however, a decreasing trend was observed. Average monthly TN and TP load decreased up to -55% and -56% respectively and were found to be dependent on flow magnitude. The annual and seasonal water yield and nutrient loads may only slightly be affected by envisaged land uses, but significantly altered by intermediate and high emission scenarios, predominantly during the spring season. The combined scenarios indicated the possibility of declining flow in future but nutrient enrichment in summer months, originating mainly from the land use scenario, that may elevate the risk of algal blooms in downstream drinking water reservoir. Hence, careful planning of future water resources in a Mediterranean catchment requires the assessment of combined effects of multiple climate models and land use scenarios on both water quantity and quality. Copyright © 2017 Elsevier B.V. All rights reserved.

An Eco-hydrologic Assessment of Small Experimental Catchments with Various Land Uses within the Panama Canal Watershed: Agua Salud Project

NASA Astrophysics Data System (ADS)

Crouch, T. D.; Ogden, F. L.; Stallard, R. F.; Smithsonian Tropical Research Institute, Panama Canal Watershed Experiment, Agua Salud Project

2010-12-01

Hydrological processes in the humid tropics are poorly understood and an important topic when it comes to water management in the seasonal tropics. The Smithsonian Tropical Research Institute, Panama Canal Watershed Experiment, Agua Salud Project, seeks to understand these processes and quantify the long-term effects of different land cover and uses across the Panama Canal Watershed. One of the project’s main objectives is to understand how reforestation effects seasonal stream flows. To meet this objective, a baseline characterization of hydrology on the small catchment scale is being assessed across different land uses typical in rural Panama. The small experimental catchments are found within Panama’s protected Soberania National Park and the adjacent headwaters of the Agua Salud and Mendoza Rivers, all of which are part of the greater Panama Canal Watershed. The land uses being monitored include a variety of control catchments as well as treated pasture sites. The catchments used for this study include a mature old regrowth forest, a 50% deforested or mosaic regrowth site, an active pasture and a monoculture invasive grass site (saccharum spontaneum) as experimental controls and two treated catchments that were recently abandoned pastures converted to teak and native species timber plantations. Installed instrumentation includes a network of rain gauges, v-notched weirs, atmometers, an eddy covariance system and an assortment of meteorological and automated geochemical sampling systems. Spatial, rainfall, runoff and ET data across these six geologically and topographically similar catchments are available from 2009 and 2010. Classic water balance and paired catchment techniques were used to compare the catchments on an annual, seasonal, and event basis. This study sets the stage for hydrologic modeling and for better understanding the effects of vegetation and land-use history on rainfall-runoff processes for the Agua Salud Project and Panama Canal

Physical responses of volcanic soils to land-use intensity in tropical headwater catchments of central Veracruz, Mexico

NASA Astrophysics Data System (ADS)

Looker, N. T.; Kolka, R.; Asbjornsen, H.; Munoz-Villers, L.; Colin, P. O.; Gómez Aguilar, L. R.; Ward, A. B.

2017-12-01

Soil physical properties, such as bulk density (ρb) and penetrability (P), may vary in response to anthropogenic disturbance and are relatively easy to measure. These variables are thus often used as proxies for soil characteristics that more directly govern process rates but are logistically challenging to sample in situ (e.g., hydraulic conductivity). We evaluated within- and among-site variability in the physical condition of the upper soil throughout eight first-order catchments in the volcanic landscape of central Veracruz, Mexico, through nested sampling of ρb, P, and ground cover characteristics. The study catchments spanned a land-use intensity gradient, ranging in dominant cover type from sugarcane to mature cloud forest, with pasture and coffee agroforest as intermediate cover types. Catchments were compared using data collected in forest inventory plots and at points distributed along the topographic position index. Analysis of this hierarchical dataset led to a ranking of catchments in terms of soil physical condition and, importantly, revealed the bias introduced by ignoring the within-catchment variability in response metrics. These results will help optimize soil sampling effort in landscapes with complex topography and land-use/cover distributions.

Time-varying parameter models for catchments with land use change: the importance of model structure

NASA Astrophysics Data System (ADS)

Pathiraja, Sahani; Anghileri, Daniela; Burlando, Paolo; Sharma, Ashish; Marshall, Lucy; Moradkhani, Hamid

2018-05-01

Rapid population and economic growth in Southeast Asia has been accompanied by extensive land use change with consequent impacts on catchment hydrology. Modeling methodologies capable of handling changing land use conditions are therefore becoming ever more important and are receiving increasing attention from hydrologists. A recently developed data-assimilation-based framework that allows model parameters to vary through time in response to signals of change in observations is considered for a medium-sized catchment (2880 km2) in northern Vietnam experiencing substantial but gradual land cover change. We investigate the efficacy of the method as well as the importance of the chosen model structure in ensuring the success of a time-varying parameter method. The method was used with two lumped daily conceptual models (HBV and HyMOD) that gave good-quality streamflow predictions during pre-change conditions. Although both time-varying parameter models gave improved streamflow predictions under changed conditions compared to the time-invariant parameter model, persistent biases for low flows were apparent in the HyMOD case. It was found that HyMOD was not suited to representing the modified baseflow conditions, resulting in extreme and unrealistic time-varying parameter estimates. This work shows that the chosen model can be critical for ensuring the time-varying parameter framework successfully models streamflow under changing land cover conditions. It can also be used to determine whether land cover changes (and not just meteorological factors) contribute to the observed hydrologic changes in retrospective studies where the lack of a paired control catchment precludes such an assessment.

Spatial variations of storm runoff pollution and their correlation with land-use in a rapidly urbanizing catchment in China.

PubMed

Qin, Hua-Peng; Khu, Soon-Thiam; Yu, Xiang-Ying

2010-09-15

The composition of land use for a rapidly urbanizing catchment is usually heterogeneous, and this may result in significant spatial variations of storm runoff pollution and increase the difficulties of water quality management. The Shiyan Reservoir catchment, a typical rapidly urbanizing area in China, is chosen as a study area, and temporary monitoring sites were set at the downstream of its 6 sub-catchments to synchronously measure rainfall, runoff and water quality during 4 storm events in 2007 and 2009. Due to relatively low frequency monitoring, the IHACRES and exponential pollutant wash-off simulation models are used to interpolate the measured data to compensate for data insufficiency. Three indicators, event pollutant loads per unit area (EPL), event mean concentration (EMC) and pollutant loads transported by the first 50% of runoff volume (FF50), were used to describe the runoff pollution for different pollutants in each sub-catchment during the storm events, and the correlations between runoff pollution spatial variations and land-use patterns were tested by Spearman's rank correlation analysis. The results indicated that similar spatial variation trends were found for different pollutants (EPL or EMC) in light storm events, which strongly correlate with the proportion of residential land use; however, they have different trends in heavy storm events, which correlate with not only the residential land use, but also agricultural and bare land use. And some pairs of pollutants (such as COD/BOD, NH(3)-N/TN) might have the similar source because they have strong or moderate positive spatial correlation. Moreover, the first flush intensity (FF50) varies with impervious land areas and different interception ratio of initial storm runoff volume should be adopted in different sub-catchments. Copyright 2010 Elsevier B.V. All rights reserved.

Aggregating land use quantity and intensity to link water quality in upper catchment of Miyun Reservoir

NASA Astrophysics Data System (ADS)

Xu, E.

2015-12-01

Land use is closely related to hydrological and biochemical processes influencing the water quality. Quantifying relationship between both of them can help effectively manage land use to improve water quality. Previous studies majorly utilized land use quantity as an indicator to link water quality parameters, which lacked an insight to the influence of land use intensity. Taking upper catchment of Miyun Reservoir as a case study, we proposed a method of aggregating land use quantity and intensity to build a new land use indicator and investigated its explanation empower on water quality. Six nutrient concentrations from 52 sub-watersheds covering the whole catchment were used to characterize spatial distributions of water eutrophication. Based on spatial techniques and empirical conversion coefficients, combined remote sensing with socio-economic statistical data, land use intensity was measured and mapped visually. Then the new land use indicator was calculated and linked to nutrient concentrations by Pearson correlation coefficients. Results demonstrated that our new land use indicator incorporating intensity information can quantify the potential different nutrients exporting abilities from land uses. Comparing to traditional indicators only characterized by land use quantity, most Pearson correlation coefficients between new indicator and water nutrient concentrations increased. New information enhanced the explanatory power of land use on water nutrient concentrations. Then it can help better understand the impact of land use on water quality and guide land use management for supporting decision making.

Simulation of future land use change and climate change impacts on hydrological processes in a tropical catchment

NASA Astrophysics Data System (ADS)

Marhaento, H.; Booij, M. J.; Hoekstra, A. Y.

2017-12-01

Future hydrological processes in the Samin catchment (278 km2) in Java, Indonesia have been simulated using the Soil and Water Assessment Tool (SWAT) model using inputs from predicted land use distributions in the period 2030 - 2050, bias corrected Regional Climate Model (RCM) output and output of six Global Climate Models (GCMs) to include climate model uncertainty. Two land use change scenarios namely a business-as-usual (BAU) scenario, where no measures are taken to control land use change, and a controlled (CON) scenario, where the future land use follows the land use planning, were used in the simulations together with two climate change scenarios namely Representative Concentration Pathway (RCP) 4.5 and 8.5. It was predicted that in 2050 settlement and agriculture area of the study catchment will increase by 33.9% and 3.5%, respectively under the BAU scenario, whereas agriculture area and evergreen forest will increase by 15.2% and 10.2%, respectively under the CON scenario. In comparison to the baseline conditions (1983 - 2005), the predicted mean annual maximum and minimum temperature in 2030 - 2050 will increase by an average of +10C, while changes in the mean annual rainfall range from -20% to +19% under RCP 4.5 and from -25% to +15% under RCP 8.5. The results show that land use change and climate change individually will cause changes in the water balance components, but that more pronounced changes are expected if the drivers are combined, in particular for changes in annual stream flow and surface runoff. It was observed that combination of the RCP 4.5 climate scenario and BAU land use scenario resulted in an increase of the mean annual stream flow from -7% to +64% and surface runoff from +21% to +102%, which is 40% and 60% more than when land use change is acting alone. Furthermore, under the CON scenario the annual stream flow and surface runoff could be potentially reduced by up to 10% and 30%, respectively indicating the effectiveness of applied

Hysteresis and parent-metabolite analyses unravel characteristic pesticide transport mechanisms in a mixed land use catchment.

PubMed

Tang, Ting; Stamm, Christian; van Griensven, Ann; Seuntjens, Piet; Bronders, Jan

2017-11-01

To properly estimate and manage pesticide occurrence in urban rivers, it is essential, but often highly challenging, to identify the key pesticide transport pathways in association to the main sources. This study examined the concentration-discharge hysteresis behaviour (hysteresis analysis) for three pesticides and the parent-metabolite concentration dynamics for two metabolites at sites with different levels of urban influence in a mixed land use catchment (25 km 2 ) within the Swiss Greifensee area, aiming to identify the dominant pesticide transport pathways. Combining an adapted hysteresis classification framework with prior knowledge of the field conditions and pesticide usage, we demonstrated the possibility of using hysteresis analysis to qualitatively infer the dominant pesticide transport pathway in mixed land-use catchments. The analysis showed that hysteresis types, and therefore the dominant transport pathway, vary among pesticides, sites and rainfall events. Hysteresis loops mostly correspond to dominant transport by flow components with intermediate response time, although pesticide sources indicate that fast transport pathways are responsible in most cases (e.g. urban runoff and combined sewer overflows). The discrepancy suggests the fast transport pathways can be slowed down due to catchment storages, such as topographic depressions in agricultural areas, a wastewater treatment plant (WWTP) and other artificial storage units (e.g. retention basins) in urban areas. Moreover, the WWTP was identified as an important factor modifying the parent-metabolite concentration dynamics during rainfall events. To properly predict and manage pesticide occurrence in catchments of mixed land uses, the hydrological delaying effect and chemical processes within the artificial structures need to be accounted for, in addition to the catchment hydrology and the diversity of pesticide sources. This study demonstrates that in catchments with diverse pesticide sources

Controls on suspended sediment, particulate and dissolved organic carbon export from two adjacent catchments with contrasting land-uses, Exmoor UK.

NASA Astrophysics Data System (ADS)

Glendell, M.; Brazier, R. E.

2012-04-01

The fluvial export of total organic carbon (particulate and dissolved) plays an important role in the transportation of organic carbon from terrestrial to aquatic ecosystems, with implications for the understanding of the global carbon cycle and calculations of regional carbon budgets. The terrestrial biosphere contains large amounts of stored carbon in the soil and vegetation, thus a small change in the terrestrial carbon pool may have significant implications for atmospheric CO2 concentrations. Since the onset of agriculture, human activities have accelerated soil erosion rates 10- to 100- fold above all estimated natural background levels, especially in the uplands and at lower latitudes, whilst increasing DOC concentrations over the past decades have been reported in rivers across Western Europe and North America, raising concerns about potential destabilisation of the terrestrial soil carbon pool. The increased input of fine sediment and organic carbon into aquatic environments is also an important factor in stream water quality, being responsible for direct ecological effects as well as transport of a range of contaminants. Many factors, such as topography, hydrological regime and vegetation are known to influence the fluvial export of carbon from catchments. However, most work to date has focused on DOC losses from either forested or peaty catchments, with only limited studies examining the controls and rates of TOC (dissolved and particulate) fluxes from agricultural catchments, particularly during flood events. This research aims to: • Quantify the fluxes of total suspended sediment, total dissolved and total particulate carbon in two adjacent catchments with contrasting land-uses and • Examine the controlling factors of total fluvial carbon fluxes in a semi-natural and agricultural catchment in order to assess the impact of agricultural land-use on fluvial carbon export. The two contrasting study catchments (the Aller and Horner), in south

Assessing the effect of land use change on catchment runoff by combined use of statistical tests and hydrological modelling: Case studies from Zimbabwe

NASA Astrophysics Data System (ADS)

Lørup, Jens Kristian; Refsgaard, Jens Christian; Mazvimavi, Dominic

1998-03-01

The purpose of this study was to identify and assess long-term impacts of land use change on catchment runoff in semi-arid Zimbabwe, based on analyses of long hydrological time series (25-50 years) from six medium-sized (200-1000 km 2) non-experimental rural catchments. A methodology combining common statistical methods with hydrological modelling was adopted in order to distinguish between the effects of climate variability and the effects of land use change. The hydrological model (NAM) was in general able to simulate the observed hydrographs very well during the reference period, thus providing a means to account for the effects of climate variability and hence strengthening the power of the subsequent statistical tests. In the test period the validated model was used to provide the runoff record which would have occurred in the absence of land use change. The analyses indicated a decrease in the annual runoff for most of the six catchments, with the largest changes occurring for catchments located within communal land, where large increases in population and agricultural intensity have taken place. However, the decrease was only statistically significant at the 5% level for one of the catchments.

Runoff production in a small agricultural catchment in Lao PDR: influence of slope, land-use and observation scale

NASA Astrophysics Data System (ADS)

Patin, J.; Ribolzi, O.; Mugler, C.; Valentin, C.; Mouche, E.

2010-12-01

After years of traditional slash and burn cultures, the Houay Pano catchment is now under high land pressures due to population resettling and environmental preservation policies. This evolution leads to rapid land-use changes in the uplands, such as fallow time reductions and growing of cash crops as teaks or banana. The catchment is located in the Luang Prabang province, in the north of Lao PDR and was selected in late 1998 as a benchmark site for the Managing Soil Erosion Consortium (MSEC). It is a small (60ha) agricultural catchment representative of the rural mountainous South East Asia : it exhibits steep cultivated slopes (from 2% to more than 110%) under a wet-dry monsoon climate. To understand the partition between runoff and infiltration, data from runoff on 20 plot experiments (1m2) under natural rainfall and with representative slopes and land uses is collected from 2003 to 2009. A simulated rainfall experiment was conducted in 2002 on bare soil plots (1m2) with different antecedent cultures. We investigate the role of crust, slope and land-use on runoff production at different scales. A model accounting for small scale variability is applied to compute the time and space variations of soil infiltrability at the plot scale (1m2) and sub-catchment scale (0.6ha). From the hypothesis of exponentially distributed infiltrabilities at the centimeter scale, we found that infiltration is log-normaly distributed over time for a given land use. The median infiltrability vary from 10mm/h under teak cultures to 150mm/h on plots with fallow. Variations along a year are tribute to many meteorological and human factors.

Influence of land use on hyporheos in catchment of the Jarama River (central Spain)

NASA Astrophysics Data System (ADS)

Iepure, S.; Martínez-Hernández, V.; Herrera, S.; de Bustamante, I.; Rasines, R.

2012-04-01

The Water Framework Directive (2000) requires integrated assessment of water bodies based on water resources but also the evaluation of land-use catchment effect on chemical and ecological conditions of aquatic ecosystems. The hyporheic zone (HZ) supporting obligate subterranean species are particularly vulnerable in river ecosystems when environmental stress occurs at surface and require management strategies to protect both the stream catchment and the aquifer that feed the stream channel. The influence of catchment land-use in the Jarama basin (central Spain) on river geomorphology and hyporheic zone granulometry, chemical and biological variables inferred from crustacean community biodiversity (species richness, taxonomic distinctness) and ecology was assessed. The study was conducted in four streams from the Madrid metropolitan area under distinct local land-use and water resource protection: i) a preserved forested natural sites where critical river ecosystem processes were unaltered or less altered by human activities, and ii) different degree of anthropogenic impact sites from agriculture, urban industrial and mining activities. The river bed permeability reduction and the increase of low sediment size input associated with changes in geomorphology of the stream channels are greatly affected by land-use changes in the Jarama watershed. Water chemical parameters linked to land-use increase from the natural stream to the urban industrial and agricultural dominated catchment. Principal coordinate analysis (PCO) and multidimensional scaling (MDS) clearly discriminate the pristine sites from forested areas by those under anthropogenic stressors. In streams draining forested areas, groundwater discharge and regular exchange between groundwater and surface water occur due to relatively high permeability of the sediments. Consequently, forested land-use produce sites of high water quality and crustacean richness (both groundwater dwellers and surface

National Climate Assessment - Land Data Assimilation System (NCA-LDAS) Data and Services at NASA GES DISC

NASA Technical Reports Server (NTRS)

Rui, Hualan; Vollmer, Bruce; Teng, Bill; Jasinski, Michael; Mocko, David; Loeser, Carlee; Kempler, Steven

2016-01-01

The National Climate Assessment-Land Data Assimilation System (NCA-LDAS) is an Integrated Terrestrial Water Analysis, and is one of NASAs contributions to the NCA of the United States. The NCA-LDAS has undergone extensive development, including multi-variate assimilation of remotely-sensed water states and anomalies as well as evaluation and verification studies, led by the Goddard Space Flight Centers Hydrological Sciences Laboratory (HSL). The resulting NCA-LDAS data have recently been released to the general public and include those from the Noah land-surface model (LSM) version 3.3 (Noah-3.3) and the Catchment LSM version Fortuna-2.5 (CLSM-F2.5). Standard LSM output variables including soil moistures temperatures, surface fluxes, snow cover depth, groundwater, and runoff are provided, as well as streamflow using a river routing system. The NCA-LDAS data are archived at and distributed by the NASA Goddard Earth Sciences Data and Information Services Center (GES DISC). The data can be accessed via HTTP, OPeNDAP, Mirador search and download, and NASA Earth data Search. To further facilitate access and use, the NCA-LDAS data are integrated into the NASA Giovanni, for quick visualization and analysis, and into the Data Rods system, for retrieval of time series of long time periods. The temporal and spatial resolutions of the NCA-LDAS data are, respectively, daily-averages and 0.125x0.125 degree, covering North America (25N 53N; 125W 67W) and the period January 1979 to December 2015. The data files are in self-describing, machine-independent, CF-compliant netCDF-4 format.

NASA Ames Celebrates Curiosity Rover's Landing on Mars (Reporter Package)

NASA Image and Video Library

2012-08-08

Nearly 7,000 people came to NASA Ames Research Center, Moffett Field, Calif., to watch the Mars Science Laboratory rover Curiosity land on Mars. A full day's worth of activities and discussions with local Mars experts informed attendees about the contributions NASA Ames made to the mission. The highlight of the event was the live NASA TV broadcast of MSL's entry, descent and landing on the Martian surface.

Catchment land use-dependent effects of barrage fishponds on the functioning of headwater streams.

PubMed

Four, Brian; Arce, Evelyne; Danger, Michaël; Gaillard, Juliette; Thomas, Marielle; Banas, Damien

2017-02-01

Extensive fish production systems in continental areas are often created by damming headwater streams. However, these lentic systems favour autochthonous organic matter production. As headwater stream functioning is essentially based on allochthonous organic matter (OM) supply, the presence of barrage fishponds on headwater streams might change the main food source for benthic communities. The goal of this study was thus to identify the effects of barrage fishponds on the functioning of headwater streams. To this end, we compared leaf litter breakdown (a key ecosystem function in headwater streams), their associated invertebrate communities and fungal biomass at sites upstream and downstream of five barrage fishponds in two dominant land use systems (three in forested catchments and two in agricultural catchments). We observed significant structural and functional differences between headwater stream ecosystems in agricultural catchments and those in forested catchments. Leaf litter decay was more rapid in forest streams, with a moderate, but not significant, increase in breakdown rate downstream from the barrage fishponds. In agricultural catchments, the trend was opposite with a 2-fold lower leaf litter breakdown rate at downstream sites compared to upstream sites. Breakdown rates observed at all sites were closely correlated with fungal biomass and shredder biomass. No effect of barrage fishponds were observed in this study concerning invertebrate community structure or functional feeding groups especially in agricultural landscapes. In forest streams, we observed a decrease in organic pollution (OP)-intolerant taxa at downstream sites that was correlated with an increase in OP-tolerant taxa. These results highlighted that the influence of barrage fishponds on headwater stream functioning is complex and land use dependent. It is therefore necessary to clearly understand the various mechanisms (competition for food resources, complementarities between

A Catchment-Based Land Surface Model for GCMs and the Framework for its Evaluation

NASA Technical Reports Server (NTRS)

Ducharen, A.; Koster, R. D.; Suarez, M. J.; Kumar, P.

1998-01-01

A new GCM-scale land surface modeling strategy that explicitly accounts for subgrid soil moisture variability and its effects on evaporation and runoff is now being explored. In a break from traditional modeling strategies, the continental surface is disaggregated into a mosaic of hydrological catchments, with boundaries that are not dictated by a regular grid but by topography. Within each catchment, the variability of soil moisture is deduced from TOP-MODEL equations with a special treatment of the unsaturated zone. This paper gives an overview of this new approach and presents the general framework for its off-line evaluation over North-America.

Interactive Effects of Storms, Drought, and Weekly Land Cover Changes on Water Quality Patterns in an Agricultural-dominated Subtropical Catchment in New Zealand

NASA Astrophysics Data System (ADS)

Julian, J.; Owsley, B.; de Beurs, K.; Hughes, A.

2013-12-01

Rivers are the funnels of landscapes, with the quality of water at the catchment outlet reflecting interactions among geomorphic processes, vegetation characteristics, weather patterns, and anthropogenic land uses. The impacts of changing climate and land cover on water quality are not straightforward; but instead, are set by the interaction of numerous landscape components at multiple spatiotemporal scales. In agricultural-dominated subtropical landscapes such as the Hoteo River Catchment in northern North Island of New Zealand, the land surface can be very dynamic, responding quickly to storms, drought, forest clearings, and grazing practices. In order to capture these short-term fluctuations, we created an 8-day land disturbance index for the catchment using MODIS Nadir BRDF-adjusted reflectance (NBAR) data (500 meter resolution) from 2000 to 2013. We also fused this time-series with Landsat TM/ETM surface reflectance data (30 meter resolution) to more precisely capture the location and extent of these land disturbances. This high-resolution land disturbance time-series was then compared to daily rainfall, daily river discharge, and monthly water samples to assess the effects of changing weather and land cover on a suite of water quality variables including water clarity, turbidity, ammonium (NH4), nitrate (NO3), total nitrogen (TN), dissolved reactive phosphate (DRP), total phosphorus (TP), and fecal coliforms. Forest clearings in the early part of our study period created the most intense land disturbances, which led to elevated turbidity and DRP during subsequent storms. Pasture areas during drought were also characterized by high disturbance indices, particularly in 2013 - the worst drought on record for northern New Zealand. Seasonal effects on land disturbance and water quality were also detected, especially for water clarity and turbidity. From 2011 to 2013, river discharge and turbidity from three sub-catchments were measured at 5-minute intervals to

Modelling the effects of land use changes on the streamflow of a peri-urban catchment in central Portugal

NASA Astrophysics Data System (ADS)

Hävermark, Saga; Santos Ferreira, Carla Sofia; Kalantari, Zahra; Di Baldassarre, Giuliano

2016-04-01

Many river basis around the world are rapidly changing together with societal development. Such developments may involve changes in land use, which in turn affect the surrounding environment in various ways. Since the start of industrialisation, the urban areas have extended worldwide. Urbanization can influence hydrological processes by decreasing evapotranspiration, infiltration and groundwater recharge as well as increasing runoff and overland flow. It is therefore of uttermost importance to understand the relationship between land use and hydrology. Although several studies have been investigating the impacts of urbanization on streamflow over the last decades, less is known on how urbanization affects hydrological processes in peri-urban areas, characterized by a complex mosaic of different land uses. This study aimed to model the impact of land use changes, specifically urbanization and commercial forest plantation, on the hydrological responses of the small Ribeira dos Covões peri-urban catchment (6,2 km2) located in central Portugal. The catchment has undergone rapid land use changes between 1958 and 2012 associated with the conversion of agricultural fields (cover area decreased from 48% to 4%) into woodland and urban areas, which increased from 44% to 56% and from 8% to 40%, respectively. For the study, the fully-distributed, physically-based modelling system MIKE SHE was used. The model was designed to examine both how past land use changes might have affected the streamflow and to investigate the impacts on hydrology of possible future scenarios, including a 50 %, 60 % and 70 % urban cover. To this end, a variety of data including daily rainfall since 1958 and forward, daily potential evapotranspiration from 2009 to 2013, monthly temperature averages from 1971 to 2013, land use for the years 1958, 1973, 1979, 1990, 1995, 2002, 2007 and 2012, streamflow from the hydrological years 2008 to 2013, catchment topography and soil types were used. The model

Stormflow influence on nutrient dynamics in micro-catchments under contrasting land use in the Cerrado and Amazon Biomes, Brazil

NASA Astrophysics Data System (ADS)

Edelmann, Katharina; Nóbrega, Rodolfo L. B.; Gerold, Gerhard

2017-04-01

The Amazon and Cerrado biomes in Brazil have been under intense land-use change during the past few decades. The conversion of native vegetation to pastures and croplands has caused impacts on hydrological processes in these biomes, resulting in increased streamflow and nutrient fluxes. Our aim was to compare the nutrient dynamics during stormflow events in two pairs of adjacent micro-catchments with similar physical characteristics under contrasting land use, i.e. native vegetation (rainforest or cerrado) and pasture. One pair of catchments was located in the Amazon and the other in the Cerrado, both on the Amazon Agricultural Frontier in the Brazilian states of Mato Grosso and Pará. We collected hydrological and hydrochemical data on 50 stormflow events on a sub-hourly resolution during the wet seasons of 2013 and 2014. We compared the dynamics of total inorganic carbon (TIC), total organic carbon (TOC), dissolved organic carbon (DOC), nitrate (NO3), calcium (Ca), potassium (K), and magnesium (Mg) in different hydrograph parts, i.e. rising limb, peak and recession limb, between the catchments within the same biome. For the Cerrado biome, our findings show that the nutrient concentrations in the stormflows were higher in the pasture catchment than in the cerrado catchment. In the Amazon biome, we found an inverse relationship with higher concentrations in the forest catchment than in the pasture catchment, except for TIC and K. Most nutrients in the cerrado catchment had the highest concentrations in the rising limb. Mg, however, reached highest concentrations during peak discharge, and lowest in the recession limb. In the adjacent pasture catchment, in contrast, the highest nutrient concentrations were observed during the peak discharge (TIC, TOC, Ca) or the recession limb (DOC, NO3, K, Mg) with lowest in the rising limb, except for NO3, which showed the lowest concentrations during peak discharge. In the Amazon forest catchment, the peak discharge showed the

Water resources planning and modelling tools for the assessment of land use change in the Luvuvhu Catchment, South Africa

NASA Astrophysics Data System (ADS)

Jewitt, G. P. W.; Garratt, J. A.; Calder, I. R.; Fuller, L.

In arid and semi-arid areas, total evaporation is a major component of the hydrological cycle and seasonal water shortages and drought are common. In these areas, the role of land use and land use change is particularly important and it is imperative that land and water resources are well managed. To aid efficient water management, it is useful to demonstrate how changing land use affects water resources. A convenient framework to consider this is through the use of the ‘blue-water’ and ‘green-water’ classification of Falkenmark, where green-water represents water use by land and blue-water represents runoff. In this study the hydrological response of nine land-use scenarios were simulated for the upper reaches of the Mutale River, an important tributary of the Luvuvhu River in S. Africa. The ACRU and HYLUC land use sensitive hydrological models, were used to investigate the change in blue and green water under the various land-use scenarios. The GIS software ArcGIS(8.3) was used to analyse available spatial data to generate inputs required by the hydrological models. The scenarios investigated included the current land use in the catchment, an increase or decrease in forest cover, and an increase or decrease in the area irrigated. Both models predict that increasing either forestry or irrigation significantly reduces the proportion of blue water in the catchment. The predictions from the models were combined with maps of catchment land use, to illustrate the changes in distribution of green and blue water in a user-friendly manner. The use of GIS in this way is designed to enable policy-makers and managers to quickly assimilate the water resource implication of the land use change.

Stream Communities Along a Catchment Land-Use Gradient: Subsidy-Stress Responses to Pastoral Development

NASA Astrophysics Data System (ADS)

Niyogi, Dev K.; Koren, Mark; Arbuckle, Chris J.; Townsend, Colin R.

2007-02-01

When native grassland catchments are converted to pasture, the main effects on stream physicochemistry are usually related to increased nutrient concentrations and fine-sediment input. We predicted that increasing nutrient concentrations would produce a subsidy-stress response (where several ecological metrics first increase and then decrease at higher concentrations) and that increasing sediment cover of the streambed would produce a linear decline in stream health. We predicted that the net effect of agricultural development, estimated as percentage pastoral land cover, would have a nonlinear subsidy-stress or threshold pattern. In our suite of 21 New Zealand streams, epilithic algal biomass and invertebrate density and biomass were higher in catchments with a higher proportion of pastoral land cover, responding mainly to increased nutrient concentration. Invertebrate species richness had a linear, negative relationship with fine-sediment cover but was unrelated to nutrients or pastoral land cover. In accord with our predictions, several invertebrate stream health metrics (Ephemeroptera-Plecoptera-Trichoptera density and richness, New Zealand Macroinvertebrate Community Index, and percent abundance of noninsect taxa) had nonlinear relationships with pastoral land cover and nutrients. Most invertebrate health metrics usually had linear negative relationships with fine-sediment cover. In this region, stream health, as indicated by macroinvertebrates, primarily followed a subsidy-stress pattern with increasing pastoral development; management of these streams should focus on limiting development beyond the point where negative effects are seen.

Land use changing SOC pool: A field investigation from four catchments on the Loess Plateau in China

NASA Astrophysics Data System (ADS)

Guo, Shengli; Wang, Rui; Hu, Yaxian

2017-04-01

The Loess Plateau in China has long been known for severe erosion, a degraded ecosystem and heavy sediment delivery to the Yellow River. Apart from, the highly erodible loess soil and the hilly geomorphology, intensive cultivation has been caused such most destructive human activities. This made the Loess Plateau once the least fertile region in China with extreme poverty. To restore soil fertility and ecosystem sustainability, a national-level project was launched in 1990s to encourage land use changes via afforestation or conversion of cropland back to grassland or woodland. After nearly three decades of land use conversion, the SOC pool in the soil can be expected to have substantially changed. However, climate conditions, geomorphic types and soil properties were spatially distinctive across the Loess Plateau. Their individual as well interactive impacts on changes of soil carbon pool during land use conversions must thus be properly accounted for. In this study, four watersheds distributed over the Loess Plateau were investigated. The four watersheds mainly consisted of three geomorphic types: wide gully, loess ridge, and round knoll. On each geomorphic feature, three land use types prevailed: cropland, grassland and woodland. In total, 695 soil samples were taken from the top 20 cm of the four watersheds during 2010 and 2011. Our results show: 1) Degrees of erosion hugely differed among the four watersheds, with Catchment A (hilly) having three times more erosion modulus than the least eroded Catchment D (gully) (12000 vs. 1800 Mg per km2 per year). 2) The increasing SOC content from 4 mg g-1 at Catchment A to 8.1 mg g-1 at Catchment D agreed well with their decreasing erosion, suggesting that geomorphology induced erosion history was the predominant factor to set the general level of watershed-scale SOC reservoir. 3) Within each watershed, grassland and woodland consistently had at least 34% more SOC than cropland, demonstrating the influence of land use

The NASA land processes program - Status and future directions

NASA Technical Reports Server (NTRS)

Murphy, R. E.

1984-01-01

For most of the past decade, NASA focused its efforts on the immediate exploitation of space-based sensors in earth-oriented programs. After an assessment of the current situation with respect to the conducted programs, NASA has restructured its earth-oriented programs to concentrate on the scientific use of its satellites while other agencies and private enterprise have assumed responsibility for programs of interest to them. In making this change of direction, NASA has conducted a series of studies to obtain information as a basis for its planning activities regarding future programs. Attention is given to a plan for Land Global Habitability, the development of a basic structure for the land program, a program plan for global biology, and a study on the role of biochemical cycles. The three major facets of the land processes program are discussed along with some examples of current work.

The influence of climate, topography and land-use on the hydrology of ephemeral upland catchments

NASA Astrophysics Data System (ADS)

Daly, E.; Webb, J.; Dresel, E.

2016-12-01

We report on an on-going project aimed at determining the effects of climate variability and land use change on water resources in ephemeral productive catchments. Meteorological data (including rainfall, solar radiation, air temperature, humidity and wind speed), streamflow and groundwater levels were collected continuously for over five years in seven ephemeral catchments in southeastern Australia. The catchments, dominated by either pasture for grazing (four) or Eucalyptus globulus (blue gum) plantations of different ages (three), were located in three different geological settings. Rainfall varied from higher than the long-term average of this area for the initial years of the study period to much drier than the long-term average for the last two years. Groundwater levels in the farm sites remained stable or slightly increased through the study period, while levels declined in all the plantation catchments, where evapotranspiration rates were greater than rainfall. The trees intercept groundwater recharge and in some areas of the catchments directly access groundwater. Streamflow occurred mainly during winter, with short-term flows in summer caused by sporadic large rainfall events. Despite the large annual rainfall variability, flow rates in each year were similar in most catchments, with the duration of flow being important in determining the annual flow. The frequency rather than the amount of rainfall events determines the generation of streamflow in the two catchments with steeper slopes. The effect of the tree plantations on streamflow varied from a substantial reduction in one catchment to no effect in another, where the tree rows are oriented predominantly downslope, allowing greater runoff. In the third plantation catchment, geology is the main driver of runoff due to capture into underlying karst conduits.

NASA Officials in MCC to decide whether to land Apollo 16 or cancel landing

NASA Technical Reports Server (NTRS)

1972-01-01

NASA Officials gather around a console in the Mission Operations Control Room (MOCR) in the Mission Control Center (MCC) prior to the making of a decision whether to land Apollo 16 on the moon or to abort the landing. Seated, left to right, are Dr. Christopher C. Kraft Jr., Director of the Manned Spacecraft Center (MSC), and Brig. Gen. James A. McDivitt (USAF), Manager, Apollo Spacecraft Program Office, MSC; and standing, left to right, are Dr. Rocco A. Petrone, Apollo Program Director, Office Manned Space Flight (OMSF), NASA HQ.; Capt. John K. Holcolmb (U.S. Navy, Ret.), Director of Apollo Operations, OMSF; Sigurd A. Sjoberg, Deputy Director, MSC; Capt. Chester M. Lee (U.S. Navy, Ret.), Apollo Mission Director, OMSF; Dale D. Myers, NASA Associate Administrator for Manned Space Flight; and Dr. George M. Low, NASA Deputy Administrator.

Catchment scale multi-objective flood management

NASA Astrophysics Data System (ADS)

Rose, Steve; Worrall, Peter; Rosolova, Zdenka; Hammond, Gene

2010-05-01

Rural land management is known to affect both the generation and propagation of flooding at the local scale, but there is still a general lack of good evidence that this impact is still significant at the larger catchment scale given the complexity of physical interactions and climatic variability taking place at this level. The National Trust, in partnership with the Environment Agency, are managing an innovative project on the Holnicote Estate in south west England to demonstrate the benefits of using good rural land management practices to reduce flood risk at the both the catchment and sub-catchment scales. The Holnicote Estate is owned by the National Trust and comprises about 5,000 hectares of land, from the uplands of Exmoor to the sea, incorporating most of the catchments of the river Horner and Aller Water. There are nearly 100 houses across three villages that are at risk from flooding which could potentially benefit from changes in land management practices in the surrounding catchment providing a more sustainable flood attenuation function. In addition to the contribution being made to flood risk management there are a range of other ecosystems services that will be enhanced through these targeted land management changes. Alterations in land management will create new opportunities for wildlife and habitats and help to improve the local surface water quality. Such improvements will not only create additional wildlife resources locally but also serve the landscape response to climate change effects by creating and enhancing wildlife networks within the region. Land management changes will also restore and sustain landscape heritage resources and provide opportunities for amenity, recreation and tourism. The project delivery team is working with the National Trust from source to sea across the entire Holnicote Estate, to identify and subsequently implement suitable land management techniques to manage local flood risk within the catchments. These

The effects of land use and its patterns on soil properties in a small catchment of the Loess Plateau.

PubMed

Wang, Jun; Fu, Bo-jie; Qiu, Yang; Chen, Li-ding

2003-03-01

Due to relatively strong human activities in the hilly area of Loess Plateau, the natural vegetation has been destroyed, and landscape pattern based on agricultural land matrix was land use mosaic composing of shrub land, grassland, woodland and orchard. This pattern has an important effect on soil moisture and soil nutrients. The Danangou catchment, a typical small catchment, was selected to study the effects of land use and its patterns on soil moisture and nutrients in this paper. The results are as follows: The comparisons of soil moisture among seven land uses for wet year and dry year were performed; (1) the average of soil moisture content for whole catchment was 12.11% in wet year, while it was 9.37% in dry year; (2) soil moisture among seven land uses significantly different in dry year, but not in wet year; (3) from wet year to dry year, the profile type of soil moisture changed from decreasing type to fluctuation-type and from fluctuant type to increasing type; (4) the increasing trend in soil moisture from the top to foot of hillslope occurred in simple land use along slope, while complicated distribution of soil moisture was observed in multiple land uses along slope. The relationship between soil nutrients and land uses and landscape positions were analysed: (1) five nutrient contents of soil organic matter (SOM), total N (TN), available N (AN), total P (TP) and available P (AP) in hilly area were lower than that in other area. SOM content was less than 1%, TN content less than 0.07%, and TP content between 0.05% and 0.06%; (2) SOM and TN contents in woodland, shrub land and grassland were significantly higher than that in fallow land and cropland, and higher level in soil fertility was found in crop-fruit intercropping land among croplands; (3) soil nutrient distribution and responses to landscape positions were variable depending on slope and the location of land use types.

Environmental care in agricultural catchments: Toward the communicative catchment

NASA Astrophysics Data System (ADS)

Martin, Peter

1991-11-01

Substantial land degradation of agricultural catchments in Australia has resulted from the importation of European farming methods and the large-scale clearing of land. Rural communities are now being encouraged by government to take responsibility for environmental care. The importance of community involvement is supported by the view that environmental problems are a function of interactions between people and their environment. It is suggested that the commonly held view that community groups cannot care for their resources is due to inappropriate social institutions rather that any inherent disability in people. The communicative catchment is developed as a vision for environmental care into the future. This concept emerges from a critique of resource management through the catchment metaphors of the reduced, mechanical, and the complex, evolving catchment, which reflect the development of systemic and people-centered approaches to environmental care. The communicative catchment is one where both community and resource managers participate collaboratively in environmental care. A methodology based on action research and systemic thinking (systemic action research) is proposed as a way of moving towards the communicative catchment of the future. Action research is a way of taking action in organizations and communities that is participative and informed by theory, while systemic thinking takes into account the interconnections and relationships between social and natural worlds. The proposed vision, methodology, and practical operating principles stem from involvement in an action research project looking at extension strategies for the implementation of total catchment management in the Hunter Valley, New South Wales.

Investigating the impact of land cover change on peak river flow in UK upland peat catchments, based on modelled scenarios

NASA Astrophysics Data System (ADS)

Gao, Jihui; Holden, Joseph; Kirkby, Mike

2014-05-01

Changes to land cover can influence the velocity of overland flow. In headwater peatlands, saturation means that overland flow is a dominant source of runoff, particularly during heavy rainfall events. Human modifications in headwater peatlands may include removal of vegetation (e.g. by erosion processes, fire, pollution, overgrazing) or pro-active revegetation of peat with sedges such as Eriophorum or mosses such as Sphagnum. How these modifications affect the river flow, and in particular the flood peak, in headwater peatlands is a key problem for land management. In particular, the impact of the spatial distribution of land cover change (e.g. different locations and sizes of land cover change area) on river flow is not clear. In this presentation a new fully distributed version of TOPMODEL, which represents the effects of distributed land cover change on river discharge, was employed to investigate land cover change impacts in three UK upland peat catchments (Trout Beck in the North Pennines, the Wye in mid-Wales and the East Dart in southwest England). Land cover scenarios with three typical land covers (i.e. Eriophorum, Sphagnum and bare peat) having different surface roughness in upland peatlands were designed for these catchments to investigate land cover impacts on river flow through simulation runs of the distributed model. As a result of hypothesis testing three land cover principles emerged from the work as follows: Principle (1): Well vegetated buffer strips are important for reducing flow peaks. A wider bare peat strip nearer to the river channel gives a higher flow peak and reduces the delay to peak; conversely, a wider buffer strip with higher density vegetation (e.g. Sphagnum) leads to a lower peak and postpones the peak. In both cases, a narrower buffer strip surrounding upstream and downstream channels has a greater effect than a thicker buffer strip just based around the downstream river network. Principle (2): When the area of change is equal

THE INFLUENCE OF CATCHMENT LAND USE ON HYDROGRAPH DYNAMICS AND IMPLICATIONS FOR STREAM BIOLOGICAL ASSEMBLAGES

EPA Science Inventory

Catchment land use impacts the rise and fall dynamic of hydrographs, and may also help explain variation in biological assemblages known to be sensitive to flow regime. We collected continuous stream depth records for the 2002 water year (5 min. intervals) from eight streams dra...

Climate and land-use change impact on faecal indicator bacteria in a temperate maritime catchment (the River Conwy, Wales)

NASA Astrophysics Data System (ADS)

Bussi, Gianbattista; Whitehead, Paul G.; Thomas, Amy R. C.; Masante, Dario; Jones, Laurence; Jack Cosby, B.; Emmett, Bridget A.; Malham, Shelagh K.; Prudhomme, Christel; Prosser, Havard

2017-10-01

Water-borne pathogen contamination from untreated sewage effluent and runoff from farms is a serious threat to the use of river water for drinking and commercial purposes, such as downstream estuarine shellfish industries. In this study, the impact of climate change and land-use change on the presence of faecal indicator bacteria in freshwater was evaluated, through the use of a recently-developed catchment-scale pathogen model. The River Conwy in Wales has been used as a case-study, because of the large presence of livestock in the catchment and the importance of the shellfish harvesting activities in its estuary. The INCA-Pathogens catchment model has been calibrated through the use of a Monte-Carlo-based technique, based on faecal indicator bacteria measurements, and then driven by an ensemble of climate projections obtained from the HadRM3-PPE model (Future Flow Climate) plus four land-use scenarios (current land use, managed ecosystem, abandonment and agricultural intensification). The results show that climate change is not expected to have a very large impact on average river flow, although it might alter its seasonality. The abundance of faecal indicator bacteria is expected to decrease in response to climate change, especially during the summer months, due to reduced precipitation, causing reduced runoff, and increased temperature, which enhances the bacterial die-off processes. Land-use change can also have a potentially large impact on pathogens. The "managed ecosystems" scenario proposed in this study can cause a reduction of 15% in average water faecal indicator bacteria and up to 30% in the 90th percentile of water faecal indicator bacteria, mainly due to the conversion of pasture land into grassland and the expansion of forest land. This study provides an example of how to assess the impacts of human interventions on the landscape, and what may be the extent of their effects, for other catchments where the human use of the natural resources in the

Land degradation and erosion control within the Moldavian Plateau of eastern Romania: a case study from Racova catchment

NASA Astrophysics Data System (ADS)

Niacsu, Lilian; Ionita, Ion; Samoila, Claudia; Grigoraş, Georgel

2017-04-01

Land degradation has been recognized as the major environmental threat in the Moldavian Plateau of eastern Romania. The Racova catchment, located in the central part of this area and extending on 32,908 ha, is significantly subjected to moderate-high rates of soil erosion, gullying, landslides and reservoir siltation. Several methods have been used to estimate land degradation indicators, such as classical research methods (field surveys and mapping, mathematical-statistical processing), present-day methods based on the GIS software, the Cs-137 technique etc. For example, the landslide inventory resulted from data collected during field surveys, interpretation of the 2005 and 2009 aerial orthophotos, exploiting very-high resolution digital elevation model (DEM) based on the topographical plans at 1:5,000 scale, and the visual analysis of products obtained from 2012 LiDAR DEM (slope map and shaded relief images). The results obtained showed that landslides, in any shape or age, are the most typical degradation processes in the Racova catchment, particularly extending on steep slopes representing north or west looking cuesta fronts, usually. At present, they cover half of the study area and most are inactive. The gullied systems amounting 4% of the catchment area consist of both types of gullies, discontinuous and continuous along valley-bottoms, respectively. In addition, the major role of gully erosion in triggering landslides and high reservoir siltation rate has been considered. Extensive conservation practices have been deployed over the 70's and 80's, namely: contour farming on arable land (under strip-cropping, buffer strip-cropping and bench terraces), reforestation over 2,000 ha (especially with black-locust on the active landslides), check dams to control gully erosion etc. Since 1990, two land reforms have been implemented (the Act No. 18/1991 and the Act No.1/2000) and their impact was very marked on soil conservation and crop yields. The major effect of

Attributes for NHDPlus Catchments (Version 1.1) for the Conterminous United States: NLCD 2001 Land Use and Land Cover

USGS Publications Warehouse

Wieczorek, Michael; LaMotte, Andrew E.

2010-01-01

This data set represents the estimated area of land use and land cover from the National Land Cover Dataset 2001 (LaMotte, 2008), compiled for every catchment of NHDPlus for the conterminous United States. The source data set represents land use and land cover for the conterminous United States for 2001. The National Land Cover Data Set for 2001 was produced through a cooperative project conducted by the Multi-Resolution Land Characteristics (MRLC) Consortium. The MRLC Consortium is a partnership of Federal agencies (http://www.mrlc.gov), consisting of the U.S. Geological Survey (USGS), the National Oceanic and Atmospheric Administration (NOAA), the U.S. Environmental Protection Agency (USEPA), the U.S. Department of Agriculture (USDA), the U.S. Forest Service (USFS), the National Park Service (NPS), the U.S. Fish and Wildlife Service (USFWS), the Bureau of Land Management (BLM), and the USDA Natural Resources Conservation Service (NRCS). The NHDPlus Version 1.1 is an integrated suite of application-ready geospatial datasets that incorporates many of the best features of the National Hydrography Dataset (NHD) and the National Elevation Dataset (NED). The NHDPlus includes a stream network (based on the 1:100,00-scale NHD), improved networking, naming, and value-added attributes (VAAs). NHDPlus also includes elevation-derived catchments (drainage areas) produced using a drainage enforcement technique first widely used in New England, and thus referred to as "the New England Method." This technique involves "burning in" the 1:100,000-scale NHD and when available building "walls" using the National Watershed Boundary Dataset (WBD). The resulting modified digital elevation model (HydroDEM) is used to produce hydrologic derivatives that agree with the NHD and WBD. Over the past two years, an interdisciplinary team from the U.S. Geological Survey (USGS), and the U.S. Environmental Protection Agency (USEPA), and contractors, found that this method produces the best quality

Let's put this in perspective: using dynamic simulation modelling to assess the impacts of farm-scale land management change on catchment-scale water quality

NASA Astrophysics Data System (ADS)

Rivers, Mark; Clarendon, Simon; Coles, Neil

2013-04-01

Natural Resource Management and Agri-industry development groups in Australia have invested considerable resources into the investigation of the economic, social and, particularly, environmental impacts of varying farming activities in a "catchment context". This research has resulted in the development of a much-improved understanding of the likely impacts of changed management practices at the farm-scale as well as the development of a number of conceptual models which place farming within this broader catchment context. The project discussed in this paper transformed a conceptual model of dairy farm phosphorus (P) management and transport processes into a more temporally and spatially dynamic model. This was then loaded with catchment-specific data and used as a "policy support tool" to allow the Australian dairy industry to examine the potential farm and catchment-scale impacts of varying dairy farm management practices within some key dairy farming regions. Models were developed, validated and calibrated using "STELLA©" dynamic modelling software for three catchments in which dairy is perceived as a significant land use. The models describe P movement and cycling within and through dairy farms in great detail and also estimate P transport through major source, sink and flow sectors of the catchments. A series of scenarios were executed for all three catchments which examined three main "groups" of tests: changes to farm P input rates; implementation of perceived environmental "Best Management Practices" (BMPs), and; changes to land use mosaics. Modifications to actual P input rates into dairy farms (not surprisingly) had a major effect on nutrient transport within and from the farms with a significant rise in nutrient loss rates at all scales with increasing fertiliser use. More surprisingly, however, even extensive environmental BMP implementation did not have marked effects on off-farm nutrient loss rates. On and off-farm riparian management implemented

Modeling relationships between catchment attributes and river water quality in southern catchments of the Caspian Sea.

PubMed

Hasani Sangani, Mohammad; Jabbarian Amiri, Bahman; Alizadeh Shabani, Afshin; Sakieh, Yousef; Ashrafi, Sohrab

2015-04-01

Increasing land utilization through diverse forms of human activities, such as agriculture, forestry, urban growth, and industrial development, has led to negative impacts on the water quality of rivers. To find out how catchment attributes, such as land use, hydrologic soil groups, and lithology, can affect water quality variables (Ca(2+), Mg(2+), Na(+), Cl(-), HCO 3 (-) , pH, TDS, EC, SAR), a spatio-statistical approach was applied to 23 catchments in southern basins of the Caspian Sea. All input data layers (digital maps of land use, soil, and lithology) were prepared using geographic information system (GIS) and spatial analysis. Relationships between water quality variables and catchment attributes were then examined by Spearman rank correlation tests and multiple linear regression. Stepwise approach-based multiple linear regressions were developed to examine the relationship between catchment attributes and water quality variables. The areas (%) of marl, tuff, or diorite, as well as those of good-quality rangeland and bare land had negative effects on all water quality variables, while those of basalt, forest land cover were found to contribute to improved river water quality. Moreover, lithological variables showed the greatest most potential for predicting the mean concentration values of water quality variables, and noting that measure of EC and TDS have inversely associated with area (%) of urban land use.

Streamflow response to future land-cover change at a headwaters catchment spanning the alpine-subalpine transition on the Colorado Front Range

NASA Astrophysics Data System (ADS)

Barnhart, T. B.; Vukomanovic, J.; Bourgeron, P.; Molotch, N. P.

2017-12-01

Land-cover change at the alpine-subalpine interface has the potential to change the water balance of mountainous, snow-dominated catchments due to the influence of vegetation on blowing snow, effective precipitation, evapotranspiration, and other processes. Understanding how land-cover change will impact water resources in snow-dominated regions is of critical importance as these locations produce a disproportionate amount of runoff relative to their land area. We coupled the LANdscape DIsturbance and Succession (LANDIS-II) model with a spatially explicit, physics-based, watershed process model, the Regional Hydro-Ecologic Simulation System (RHESSys), to simulate land-cover change and its impact on the water balance in a 6.6 km­2 headwater catchment that spans the alpine-subalpine transition on the Colorado Front Range. We simulated two potential futures of air temperature warming (+4 °C/century) to 2100: a) increased precipitation (+15%, MP) and b) decreased precipitation (-15%, LP). As the LANDIS-II model simulates forest succession in a stochastic manner, we use three LANDIS-II model runs each for the MP and LP future forcing conditions. For both MP and LP, the RHESSys forcing data set was updated to reflect the changes in precipitation and temperature used to generate the land-cover futures. Forest cover in the catchment increased from 72% in 2000 to 84% and 83% in 2050 and to 95% and 92% in 2100 for MP and LP, respectively. Somewhat surprisingly, this increase in forest cover led to mean increases in streamflow production of 9% for MP and 3% for LP in 2050. In 2100, mean streamflow production increased by 15% and 6% for the MP and LP scenarios, respectively. This is likely due to increases in effective precipitation as the catchment forested and blowing snow decreased. Indeed, catchment effective precipitation increased from 94% in 2000 to 97% and 99% in 2050 and 2100, respectively, for both MP and LP conditions. This result counters previous work as runoff

Advance Inspection of NASA Next Mars Landing Site

NASA Image and Video Library

2017-03-29

This map shows footprints of images taken from Mars orbit by the High Resolution Imaging Science Experiment (HiRISE) camera as part of advance analysis of the area where NASA's InSight mission will land in 2018. The final planned image of the set is targeted to fill in the yellow-outlined rectangle on March 30, 2017. HiRISE is one of six science instruments on NASA's Mars Reconnaissance Orbiter, which reached Mars in 2006 and surpassed 50,000 orbits on March 27, 2017. The map covers an area about 100 miles (160 kilometers) across. HiRISE has been used since 2006 to inspect dozens of candidate landing sites on Mars, including the sites where the Phoenix and Curiosity missions landed in 2008 and 2012. The site selected for InSight's Nov. 26, 2018, landing is on a flat plain in the Elysium Planitia region of Mars, between 4 and 5 degrees north of the equator. HiRISE images are detailed enough to reveal individual boulders big enough to be a landing hazard. The March 30 observation that completes the planned advance imaging of this landing area brings the number of HiRISE images of the area to 73. Some are pairs covering the same ground. Overlapping observations provide stereoscopic, 3-D information for evaluating characteristics such as slopes. On this map, coverage by stereo pairs is coded in pale blue, compared to the gray-green of single HiRISE image footprints. The ellipses on the map are about 81 miles (130 kilometers) west-to-east by about 17 miles (27 kilometers) north-to-south. InSight has about 99 percent odds of landing within the ellipse for which it is targeted. The three ellipses indicate landing expectations for three of the possible InSight launch dates: white outline for launch at the start of the launch period, on May 5, 2018; blue for launch on May 26, 2018; orange for launch on June 8, 2018. InSight -- an acronym for "Interior Exploration using Seismic Investigations, Geodesy and Heat Transport" -- will study the deep interior of Mars to improve

Dynamic integration of land use changes in a hydrologic assessment of a rapidly developing Indian catchment.

PubMed

Wagner, Paul D; Bhallamudi, S Murty; Narasimhan, Balaji; Kantakumar, Lakshmi N; Sudheer, K P; Kumar, Shamita; Schneider, Karl; Fiener, Peter

2016-01-01

Rapid land use and land-cover changes strongly affect water resources. Particularly in regions that experience seasonal water scarcity, land use scenario assessments provide a valuable basis for the evaluation of possible future water shortages. The objective of this study is to dynamically integrate land use model projections with a hydrologic model to analyze potential future impacts of land use change on the water resources of a rapidly developing catchment upstream of Pune, India. For the first time projections from the urban growth and land use change model SLEUTH are employed as a dynamic input to the hydrologic model SWAT. By this means, impacts of land use changes on the water balance components are assessed for the near future (2009-2028) employing four different climate conditions (baseline, IPCC A1B, dry, wet). The land use change modeling results in an increase of urban area by +23.1% at the fringes of Pune and by +12.2% in the upper catchment, whereas agricultural land (-14.0% and -0.3%, respectively) and semi-natural area (-9.1% and -11.9%, respectively) decrease between 2009 and 2028. Under baseline climate conditions, these land use changes induce seasonal changes in the water balance components. Water yield particularly increases at the onset of monsoon (up to +11.0mm per month) due to increased impervious area, whereas evapotranspiration decreases in the dry season (up to -15.1mm per month) as a result of the loss of irrigated agricultural area. As the projections are made for the near future (2009-2028) land use change impacts are similar under IPCC A1B climate conditions. Only if more extreme dry years occur, an exacerbation of the land use change impacts can be expected. Particularly in rapidly changing environments an implementation of both dynamic land use change and climate change seems favorable to assess seasonal and gradual changes in the water balance. Copyright © 2015 Elsevier B.V. All rights reserved.

The Demonstration Test Catchment Approach to Land and Water Management in the river Eden Watershed, UK. (Invited)

NASA Astrophysics Data System (ADS)

Jonczyk, J.; Quinn, P. F.; Haygarth, P.; Reaney, S.; Wilkinson, M.; Burke, S.; McGonigle, D.; Harris, B.

2010-12-01

The Demonstration Test Catchment (DTC) initiative is a five year project to address pollution issues in catchments. The initiative will study the wider environmental problems suffered by catchments which are under intense farming pressures and potential climate change impacts. The UK Department for Food, Agriculture and Rural Affairs (Defra) in partnership with the Environment Agency for England and Wales (EA) have funded this initiative to answer key policy concerns in catchments. The first key step has been the establishment of a ‘research platform’ at three catchments in the UK (The Eden, Wensum and Hampshire Avon) whereby funding of 9.3 million dollars has gone into funding new equipment and pollution sampling regimes have been established. Within each catchment between three and four, 8-10km2 sub-catchments have been established. The experimental design and thinking for DTCs will be explained fully in this paper. The next phase of the project will install an extensive suite of land management and pollution mitigation interventions. In parallel to this monitoring work, a full knowledge exchange package will seek to engage with farmers, the rural community and understand the governance regime at the broader catchment scale. There is also a need for a modelling component to upscale the findings to the whole of the UK. Whilst this is an ambitious goal, there is a very basic commitment of working with rural communities to come up with real solutions that will help underpin effective policy making for the future. The research platform covers a multi-scale approach to the monitoring strategy that will allow local grouping of mitigation measures to be studied local in terms of impact and propagated to the catchment scale. Even with high level of funding, the DTC can only fully instrument a catchment of 8-10km2. Beyond this scale, the EA and the standard catchment monitoring will continue as normal. The focus here is to prove that mitigation can be achieved within

A 125 year record of fluvial calcium flux from a temperate catchment: Interplay of climate, land-use change and atmospheric deposition

NASA Astrophysics Data System (ADS)

Worrall, F.; Howden, N. J. K.; Burt, T. P.

2012-10-01

SummaryThis paper analyses the world's longest fluvial record of water hardness and calcium (Ca) concentration. We used records of permanent and temporary hardness and river flow for the UK's River Thames (catchment area 9998 km2) to estimate annual Ca flux from the river since 1883. The Thames catchment has a mix of agricultural and urban land use; it is dominated by mineral soils with groundwater contributing around 60% of river flow. Since the late 1800s, the catchment has undergone widespread urbanisation and climate warming, but has also been subjected to large-scale land-use change, especially during World War II and agricultural intensification in the 1960s. Here, we use a range of time series methods to explore the relative importance of these drivers in determining catchment-scale biogeochemical response. Ca concentrations in the Thames rose to a peak in the late 1980s (106 mg Ca/l). The flux of Ca peaked in 1916 at 385 ktonnes Ca/yr; the minimum was in 1888 at 34 ktonnes Ca/yr. For both the annual average Ca concentration and the annual flux of Ca, there were significant increases with time; a significant positive memory effect relative to the previous year; and significant correlation with annual water yield. No significant correlation was found with either temperature or land use, but sulphate deposition was found to be significant. It was also possible, for a shorter time series, to show a significant relationship with inorganic nitrogen inputs into the catchment. We suggest that ionic inputs did not acidify the mineral soils of the catchment but did cause the leaching of metals, so we conclude that the decline in river Ca concentrations is caused by the decline in both S and N inputs.

Incorporating JULES into NASA's Land Information System (LIS) and Investigations of Land-Atmosphere Coupling

NASA Technical Reports Server (NTRS)

Santanello, Joseph

2011-01-01

NASA's Land Information System (LIS; lis.gsfc.nasa.gov) is a flexible land surface modeling and data assimilation framework developed over the past decade with the goal of integrating satellite- and ground-based observational data products and advanced land surface modeling techniques to produce optimal fields of land surface states and fluxes. LIS features a high performance and flexible design, and operates on an ensemble of land surface models for extension over user-specified regional or global domains. The extensible interfaces of LIS allow the incorporation of new domains, land surface models (LSMs), land surface parameters, meteorological inputs, data assimilation and optimization algorithms. In addition, LIS has also been demonstrated for parameter estimation and uncertainty estimation, and has been coupled to the Weather Research and Forecasting (WRF) mesoscale model. A visiting fellowship is currently underway to implement JULES into LIS and to undertake some fundamental science on the feedbacks between the land surface and the atmosphere. An overview of the LIS system, features, and sample results will be presented in an effort to engage the community in the potential advantages of LIS-JULES for a range of applications. Ongoing efforts to develop a framework for diagnosing land-atmosphere coupling will also be presented using the suite of LSM and PBL schemes available in LIS and WRF along with observations from the U. S .. Southern Great Plains. This methodology provides a potential pathway to study factors controlling local land-atmosphere coupling (LoCo) using the LIS-WRF system, which will serve as a testbed for future experiments to evaluate coupling diagnostics within the community.

Runoff changes have a land cover specific effect on the seasonal fluxes of terminal electron acceptors in the boreal catchments.

PubMed

Mattsson, Tuija; Lehtoranta, Jouni; Ekholm, Petri; Palviainen, Marjo; Kortelainen, Pirkko

2017-12-01

Climate change influences the volume and seasonal distribution of runoff in the northern regions. Here, we study how the seasonal variation in the runoff affects the concentrations and export of terminal electron acceptors (i.e. TEAs: NO 3 , Mn, Fe and SO 4 ) in different boreal land-cover classes. Also, we make a prediction how the anticipated climate change induced increase in runoff will alter the export of TEAs in boreal catchments. Our results show that there is a strong positive relationship between runoff and the concentration of NO 3 -N, Mn and Fe in agricultural catchments. In peaty catchments, the relationship is poorer and the concentrations of TEAs tend to decrease with increasing runoff. In forested catchments, the correlation between runoff and TEA concentrations was weak. In most catchments, the concentrations of SO 4 decrease with an increase in runoff regardless of the land cover or season. The wet years export much higher amounts of TEAs than the dry years. In southern agricultural catchments, the wet years increased the TEA export for both spring (January-May) and autumn (September-December) periods, while in the peaty and forested catchments in eastern and northern Finland the export only increased in the autumn. Our predictions for the year 2099 indicate that the export of TEAs will increase especially from agricultural but also from forested catchments. Additionally, the predictions show an increase in the export of Fe and SO 4 for all the catchments for the autumn. Thus, the climate induced change in the runoff regime is likely to alter the exported amount of TEAs and the timing of the export downstream. The changes in the amounts and timing in the export of TEAs have a potential to modify the mineralization pathways in the receiving water bodies, with feedbacks in the cycling of C, nutrients and metals in aquatic ecosystems. Copyright © 2017 Elsevier B.V. All rights reserved.

Impact of land use changes on hydrology of Mt. Kilimanjaro. The case of Lake Jipe catchment

NASA Astrophysics Data System (ADS)

Ngugi, Keziah; Ogindo, Harun; Ertsen, Maurits

2015-04-01

Mt. Kilimanjaro is an important water tower in Kenya and Tanzania. Land degradation and land use changes have contributed to dwindling surface water resources around Mt. Kilimanjaro. This study focuses on Lake Jipe catchment of about 451Km2 (Ndetei 2011) which is mainly drained by River Lumi, a tributary of river Pangani. River Lumi starts from Mt. Kilimanjaro and flows North east wards to cross the border from Tanzania to Kenya eventually flowing into Lake Jipe which is a trans-boundary lake. The main purpose of this study was to investigate historical land use changes and relate this to reduction in surface water resources. The study will propose measures that could restore the catchment thereby enhancing surface water resources feeding Lake Jipe. A survey was conducted to document community perspectives of historical land use changes. This information was corroborated using Landsat remote sensed images spanning the period 1985-2013 to determine changes in the land cover due to human activities on Lake Jipe Catchment. River Lumi flow data was obtained from Water Resources Management Authority and analyzed for flow trends. The dwindling extent of the Lake was obtained from the community's perspective survey and by Landsat images. Community survey and remote sensing indicated clearing of the forest on the mountain and conversion of the same to crop production fields; damming of river Lumi in Tanzania, conversion of bush land to crop production fields further downstream of river Lumi and irrigation. There is heavy infestation of the invasive species Prosopis juliflora which had aggressively colonized grazing land and blocked irrigation canals. Other land use changes include land fragmentation due to subdivision. Insecure land tenure was blamed for failure by farmers to develop soil and water conservation infrastructure. Available River gauging data showed a general decline in river flow. Heavy flooding occurred during rainy seasons. Towards Lake Jipe after the river

Bioavailability of riverine dissolved organic matter in three Baltic Sea estuaries and the effect of catchment land-use

NASA Astrophysics Data System (ADS)

Asmala, E.; Autio, R.; Kaartokallio, H.; Pitkänen, L.; Stedmon, C. A.; Thomas, D. N.

2013-06-01

The microbial degradation of dissolved organic carbon and nitrogen (DOC, DON) was studied in three boreal estuaries with contrasting land use patterns (Kiiminkijoki - natural forest and peatland; Kyrönjoki - agricultural; Karjaanjoki - mixed/urban). Bioassays conducted for 12-18 days were used in 3 seasons at in situ temperatures. Besides the bulk parameters, a suite of dissolved organic matter (DOM) quality parameters were investigated, including colored DOM (CDOM), fluorescent DOM and the molecular weight of DOM. Bioavailable DOC and DON pools varied significantly between the estuaries, from 7.9% in Kiiminkijoki to 10.6% in Karjaanjoki and from 5.5% in Kiiminkijoki to 21.9% in Kyrönjoki, respectively. DOM originating from catchment dominated by natural forests and peatlands had the lowest DOC and DON degradation rates, as well as the lowest proportions of biodegradable DOC and DON. A greater proportion of agricultural land in the catchment increased the bioavailability of DON, but not the bioavailability of DOC. Also DOM quality varied significantly between the estuaries, and DOM originating from the agricultural Kyrönjoki catchment sustained higher DOC and DON degradation rates and higher bacterial growth efficiency (BGE) compared to those of the natural forest and peat dominated Kiiminkijoki catchment. The quality of DOM, indicated by differences in CDOM, fluorescent DOM and molecular weight, varied between estuaries with differing land use and was concluded to be major driver of BGE of these systems and thereafter to the microbial CO2 fluxes from the estuaries. The differences in BGE resulted in a 5-fold differences in the calculated daily bacterial CO2-emissions between the study estuaries due to bacterial activity, ranging from 40 kg C d-1 in Karjaanjoki estuary to 200 kg C d-1 in Kyrönjoki estuary. Two of the study systems (Karjaanjoki, mixed land use; Kyrönjoki, intensive agriculture) in which the DOM pool had lower DOC : DON ratio, smaller molecular

Modelling the impacts of altered management practices, land use and climate changes on the water quality of the Millbrook catchment-reservoir system in South Australia.

PubMed

Nguyen, Hong Hanh; Recknagel, Friedrich; Meyer, Wayne; Frizenschaf, Jacqueline; Shrestha, Manoj Kumar

2017-11-01

Sustainable management of drinking water reservoirs requires taking into account the potential effects of their catchments' development. This study is an attempt to estimate the daily patterns of nutrients transport in the catchment - reservoir systems through the application of the ensemble of complementary models SWAT-SALMO. SWAT quantifies flow, nitrate and phosphate loadings originating in catchments before entering downstream reservoirs meanwhile SALMO determines phosphate, nitrate, and chlorophyll-a concentrations within the reservoirs. The study applies to the semi-arid Millbrook catchment-reservoir system that supplies drinking water to north-eastern suburbs of Adelaide, South Australia. The catchment hosts viti- and horticultural land uses. The warm-monomictic, mesotrophic reservoir is artificially aerated in summer. After validating the simulation results for both Millbrook catchment and reservoir, a comprehensive scenario analysis has been conducted to reveal cascading effects of altered management practices, land uses and climate conditions on water quality in the reservoir. Results suggest that the effect on reservoir condition in summer would be severe, most likely resulting in chlorophyll-a concentrations of greater than 40 μg/l if the artificial destratification was not applied from early summer. A 50% curbing of water diversion from an external pipeline to the catchment will slightly limit chlorophyll-a concentrations by 1.22% as an effect of reduced inflow phosphate loads. The simulation of prospective land use scenarios converting 50% of present pasture in the Millbrook catchment into residential and orchards areas indicates an increase of summer chlorophyll-a concentrations by 9.5-107.9%, respectively in the reservoir. Global warming scenarios based on the high emission simulated by SWAT-SALMO did result in earlier growth of chlorophyll-a but overall the effects on water quality in the Millbrook reservoir was not significant. However scenarios

Coupling of Markov chains and cellular automata spatial models to predict land cover changes (case study: upper Ci Leungsi catchment area)

NASA Astrophysics Data System (ADS)

Marko, K.; Zulkarnain, F.; Kusratmoko, E.

2016-11-01

Land cover changes particular in urban catchment area has been rapidly occur. Land cover changes occur as a result of increasing demand for built-up area. Various kinds of environmental and hydrological problems e.g. floods and urban heat island can happen if the changes are uncontrolled. This study aims to predict land cover changes using coupling of Markov chains and cellular automata. One of the most rapid land cover changes is occurs at upper Ci Leungsi catchment area that located near Bekasi City and Jakarta Metropolitan Area. Markov chains has a good ability to predict the probability of change statistically while cellular automata believed as a powerful method in reading the spatial patterns of change. Temporal land cover data was obtained by remote sensing satellite imageries. In addition, this study also used multi-criteria analysis to determine which driving factor that could stimulate the changes such as proximity, elevation, and slope. Coupling of these two methods could give better prediction model rather than just using it separately. The prediction model was validated using existing 2015 land cover data and shown a satisfactory kappa coefficient. The most significant increasing land cover is built-up area from 24% to 53%.

Spatial and temporal assessment of driving and conditioning factors and their impact on land use / land cover change in the Xiangxi Catchment, Three Gorges Region

NASA Astrophysics Data System (ADS)

Seeber, Christoph; Hartmann, Heike; Xiang, Wei; King, Lorenz

2010-05-01

Land use / land cover change (LUCC) is the most important human alteration of the earth's surface and is primarily studied in cases where it leads to severe environmental problems. The construction of the Three Gorges Dam on the Yangtze River in China has an extensive impact on the ecosystems and the local population. To assess its impact, the Xiangxi Catchment is taken as an example. The outlet of the Xiangxi River, a northern tributary of the Yangtze River, is located about 40 km upstream of the Three Gorges Dam. Due to the loss of fertile arable land and residential land which is mainly induced by the inundation and measures of resettlement, enormous LUCC is observed in the study area by depicting the land use / land cover by classification of LandsatTM data retrieved in 1987 and 2007. LUCC in the Xiangxi Catchment during this period can generally be characterized as decrease of cultivated land, increase of woodland and fallow land, and a shift in cropping from traditional smallholder farming to the establishment of citrus orchards, which are implemented as cash crops. Not only the inundation and the resettlement have an impact on LUCC, also the newly built and improved traffic infrastructure, growth of urban structures and land use policies in terms of environmental protection are expected to play an important role concerning LUCC. To assess the spatial and temporal impact of influencing factors, a LUCC gradient is generated based on post-classification change analysis of multispectral data. Furthermore, inter-stages between 1987 and 2007 have to be examined, to reach for a higher temporal resolution, which shall help to figure out temporal relationships between LUCC and the occurrence of driving factors. Once influence factors and and their spatial and temporal impacts are identified, a basis for predicting LUCC in the future for is provided for this area.

Downscaling catchment scale flood risk to contributing sub-catchments to determine the optimum location for flood management.

NASA Astrophysics Data System (ADS)

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

2010-05-01

The recent increase in flood frequency and magnitude has been hypothesised to have been caused by either climate change or land management. Field scale studies have found that changing land management practices does affect local runoff and streamflow, but upscaling these effects to the catchment scale continues to be problematic, both conceptually and more importantly methodologically. The impact on downstream flood risk is highly dependent upon where the changes are in the catchment, indicating that some areas of the catchment are more important in determining downstream flood risk than others. This is a major flaw in the traditional approach to studying the effect of land use on downstream flood risk: catchment scale hydrological models, which treat every cell in the model equally. We are proposing an alternative ideological approach for doing flood management research, which is underpinned by downscaling the downstream effect (problem i.e. flooding) to the upstream causes (contributing sub-catchments). It is hoped that this approach could have several benefits over the traditional upscaling approach. Firstly, it provides an efficient method to prioritise areas for land use management changes to be implemented to reduce downstream flood risk. Secondly, targets for sub-catchment hydrograph change can be determined which will deliver the required downstream effect. Thirdly, it may be possible to detect the effect of land use changes in upstream areas on downstream flood risk, by weighting the areas of most importance in hydrological models. Two methods for doing this downscaling are proposed; 1) data-based statistical analysis; and 2) hydraulic modelling-based downscaling. These will be outlined using the case study of the River Eden, Cumbria, NW England. The data-based methodology uses the timing and magnitude of floods for each sub-catchment. Principal components analysis (PCA) is used to simplify sub-catchment interactions and optimising stepwise regression is

Bioavailability of riverine dissolved organic matter in three Baltic Sea estuaries and the effect of catchment land use

NASA Astrophysics Data System (ADS)

Asmala, E.; Autio, R.; Kaartokallio, H.; Pitkänen, L.; Stedmon, C. A.; Thomas, D. N.

2013-11-01

The microbial degradation of dissolved organic carbon and nitrogen (DOC, DON) was studied in three Finnish boreal estuaries with contrasting land use patterns (Kiiminkijoki - natural forest and peatland; Kyrönjoki - agricultural; Karjaanjoki - mixed/urban). Bioassays of 12-18 d long durations were used in 3 seasons at in situ temperatures. Besides the bulk parameters, a suite of dissolved organic matter (DOM) quality parameters were also investigated, including colored DOM (CDOM), fluorescent DOM and the molecular weight of DOM. Bioavailable DOC and DON pools varied significantly between the estuaries, from 7.9 to 10.6% and from 5.5 to 21.9%, respectively. DOM originating from the catchment dominated by natural forests and peatlands (Kiiminkijoki) had the lowest DOC and DON degradation rates, as well as the lowest proportions of biodegradable DOC and DON. A greater proportion of agricultural land in the catchment increased the bioavailability of DON, but not the bioavailability of DOC (Kyrönjoki). Additionally, DOM quality varied significantly between the estuaries, and DOM originating from the agricultural Kyrönjoki catchment sustained higher DOC and DON degradation rates and higher bacterial growth efficiency (BGE) compared to those of the natural forest and peat dominated Kiiminkijoki catchment. The quality of DOM, indicated by differences in CDOM, fluorescent DOM and molecular weight, varied between estuaries with differing land use and was concluded to be major driver of BGE of these systems and thereafter to the microbial CO2 fluxes from the estuaries. The differences in BGE resulted in a 5-fold difference in the calculated daily bacterial CO2 emissions between the study's estuaries due to bacterial activity, ranging from 40 kg C d-1 in the Karjaanjoki estuary to 200 kg C d-1 in the Kyrönjoki estuary. Lower DOC:DON ratios, smaller molecular weight and higher CDOM absorption spectral slope values of DOM resulted in higher proportion of the initial DOC and

Pre-Launch Evaluation of the NPP VIIRS Land and Cryosphere EDRs to Meet NASA's Science Requirements

NASA Technical Reports Server (NTRS)

Roman, Miguel O.; Justice, Chris; Csiszar, Ivan; Key, Jeffrey R.; Devadiga, Sadashiva; Davidson, carol; Wolfe, Robert; Privette, Jeff

2011-01-01

This paper summarizes the NASA Visible Infrared Imaging Radiometer Suite (VIIRS) Land Science team's findings to date with respect to the utility of the VIIRS Land and Cryosphere EDRs to meet NASA's science requirements. Based on previous assessments and results from a recent 51-day global test performed by the Land Product Evaluation and Analysis Tool Element (Land PEATE), the NASA VIIRS Land Science team has determined that, if all the Land and Cryosphere EDRs are to serve the needs of the science community, a number of changes to several products and the Interface Data Processing Segment (IDPS) algorithm processing chain will be needed. In addition, other products will also need to be added to the VIIRS Land product suite to provide continuity for all of the MODIS land data record. As the NASA research program explores new global change research areas, the VIIRS instrument should also provide the polar-orbiting imager data from which new algorithms could be developed, produced, and validated.

Soil erosion and sediment delivery in a mountain catchment under scenarios of land use change using a spatially distributed numerical model

NASA Astrophysics Data System (ADS)

Alatorre, L. C.; Beguería, S.; Lana-Renault, N.; Navas, A.; García-Ruiz, J. M.

2012-05-01

Soil erosion and sediment yield are strongly affected by land use/land cover (LULC). Spatially distributed erosion models are of great interest to assess the expected effect of LULC changes on soil erosion and sediment yield. However, they can only be applied if spatially distributed data is available for their calibration. In this study the soil erosion and sediment delivery model WATEM/SEDEM was applied to a small (2.84 km2) experimental catchment in the Central Spanish Pyrenees. Model calibration was performed based on a dataset of soil redistribution rates derived from point 137Cs inventories, allowing capture differences per land use in the main model parameters. Model calibration showed a good convergence to a global optimum in the parameter space, which was not possible to attain if only external (not spatially distributed) sediment yield data were available. Validation of the model results against seven years of recorded sediment yield at the catchment outlet was satisfactory. Two LULC scenarios were then modeled to reproduce land use at the beginning of the twentieth century and a hypothetic future scenario, and to compare the simulation results to the current LULC situation. The results show a reduction of about one order of magnitude in gross erosion (3180 to 350 Mg yr-1) and sediment delivery (11.2 to 1.2 Mg yr-1 ha-1) during the last decades as a result of the abandonment of traditional land uses (mostly agriculture) and subsequent vegetation recolonization. The simulation also allowed assessing differences in the sediment sources and sinks within the catchment.

Changes in catchment hydrology in relation to vegetation recovery: a comparative modelling experiment

NASA Astrophysics Data System (ADS)

Lana-Renault, Noemí; Karssenberg, Derek; Latron, Jérôme; Serrano, Mā Pilar; Regüés, David; Bierkens, Marc F. P.

2010-05-01

Mediterranean mountains have been largely affected by land abandonment and subsequent vegetation recovery, with a general expansion of shrubs and forests. Such a large scale land-cover change has modified the hydrological behavior of these areas, with significant impact on runoff production. Forecasting the trend of water resources under future re-vegetation scenarios is of paramount importance in Mediterranean basins, where water management relies on runoff generated in these areas. With this purpose, a modelling experiment was designed based on the information collected in two neighbouring research catchments with a different history of land use in the central Spanish Pyrenees. One (2.84 km2) is an abandoned agricultural catchment subjected to plant colonization and at present mainly covered by shrubs. The other (0.92 km2) is a catchment covered by dense natural forest, representative of undisturbed environments. Here we present the results of the analysis of the hydrological differences between the two catchments, and a description of the approach and results of the modelling experiment. In a statistical analysis of the field data, significant differences were observed in the streamflow response of the two catchments. The forested catchment recorded fewer floods per year compared to the old agricultural catchment, and its hydrological response was characterised by a marked seasonality, with autumn and spring as the only high flow periods. Stormflow was generally higher in the old agricultural catchment, especially for low to intermediate size events; only for large events the stormflow in the forested catchment was sometimes greater. Under drier conditions, the relative differences in the stormflow between the two catchments tended to increase whereas under wet conditions they tended to be similar. The forested catchment always reacted more slowly to rainfall, with lower peakflows (generally one order of magnitude lower) and longer recession limbs. The modelling

An approach to predict water quality in data-sparse catchments using hydrological catchment similarity

NASA Astrophysics Data System (ADS)

Pohle, Ina; Glendell, Miriam; Stutter, Marc I.; Helliwell, Rachel C.

2017-04-01

An understanding of catchment response to climate and land use change at a regional scale is necessary for the assessment of mitigation and adaptation options addressing diffuse nutrient pollution. It is well documented that the physicochemical properties of a river ecosystem respond to change in a non-linear fashion. This is particularly important when threshold water concentrations, relevant to national and EU legislation, are exceeded. Large scale (regional) model assessments required for regulatory purposes must represent the key processes and mechanisms that are more readily understood in catchments with water quantity and water quality data monitored at high spatial and temporal resolution. While daily discharge data are available for most catchments in Scotland, nitrate and phosphorus are mostly available on a monthly basis only, as typified by regulatory monitoring. However, high resolution (hourly to daily) water quantity and water quality data exist for a limited number of research catchments. To successfully implement adaptation measures across Scotland, an upscaling from data-rich to data-sparse catchments is required. In addition, the widespread availability of spatial datasets affecting hydrological and biogeochemical responses (e.g. soils, topography/geomorphology, land use, vegetation etc.) provide an opportunity to transfer predictions between data-rich and data-sparse areas by linking processes and responses to catchment attributes. Here, we develop a framework of catchment typologies as a prerequisite for transferring information from data-rich to data-sparse catchments by focusing on how hydrological catchment similarity can be used as an indicator of grouped behaviours in water quality response. As indicators of hydrological catchment similarity we use flow indices derived from observed discharge data across Scotland as well as hydrological model parameters. For the latter, we calibrated the lumped rainfall-runoff model TUWModel using multiple

Effect of Land Use, Seasonality, and Hydrometeorological Conditions on the K+ Concentration-Discharge Relationship During Different Types of Floods in Carpathian Foothills Catchments (Poland).

PubMed

Siwek, Joanna P; Żelazny, Mirosław; Siwek, Janusz; Szymański, Wojciech

2017-01-01

The purpose of the study was to determine the role of land use, seasonality, and hydrometeorological conditions on the relationship between stream water potassium (K + ) concentration and discharge during different types of floods-short- and long-duration rainfall floods as well as snowmelt floods on frozen and thawed soils. The research was conducted in small catchments (agricultural, woodland, mixed-use) in the Carpathian Foothills (Poland). In the woodland catchment, lower K + concentrations were noted for each given specific runoff value for summer rainfall floods versus snowmelt floods (seasonal effect). In the agricultural and mixed-use catchments, the opposite was true due to their greater ability to flush K + out of the soil in the summer. In the stream draining woodland catchment, higher K + concentrations occurred during the rising limb than during the falling limb of the hydrograph (clockwise hysteresis) for all flood types, except for snowmelt floods with the ground not frozen. In the agricultural catchment, clockwise hystereses were produced for short- and long-duration rainfall floods caused by high-intensity, high-volume rainfall, while anticlockwise hystereses were produced for short- and long-duration rainfall floods caused by low-intensity, low-volume rainfall as well as during snowmelt floods with the soil frozen and not frozen. In the mixed-use catchment, the hysteresis direction was also affected by different lag times for water reaching stream channels from areas with different land use. K + hystereses for the woodland catchment were more narrow than those for the agricultural and mixed-use catchments due to a smaller pool of K + in the woodland catchment. In all streams, the widest hystereses were produced for rainfall floods preceded by a long period without rainfall.

Long-Term Hydrologic Impact Assessment of Non-point Source Pollution Measured Through Land Use/Land Cover (LULC) Changes in a Tropical Complex Catchment

NASA Astrophysics Data System (ADS)

Abdulkareem, Jabir Haruna; Sulaiman, Wan Nor Azmin; Pradhan, Biswajeet; Jamil, Nor Rohaizah

2018-03-01

The contribution of non-point source pollution (NPS) to the contamination of surface water is an issue of growing concern. Non-point source (NPS) pollutants are of various types and altered by several site-specific factors making them difficult to control due to complex uncertainties involve in their behavior. Kelantan River basin, Malaysia is a tropical catchment receiving heavy monsoon rainfall coupled with intense land use/land cover (LULC) changes making the area consistently flood prone thereby deteriorating the surface water quality in the area. This study was conducted to determine the spatio-temporal variation of NPS pollutant loads among different LULC changes and to establish a NPS pollutant loads relationships among LULC conditions and sub-basins in each catchment. Four pollutants parameters such as total suspended solids (TSS), total phosphorus (TP), total nitrogen (TN) and ammonia nitrogen (AN) were chosen with their corresponding event mean concentration values (EMC). Soil map and LULC change maps corresponding to 1984, 2002 and 2013 were used for the calculation of runoff and NPS pollutant loads using numeric integration in a GIS environment. Analysis of Variance (ANOVA) was conducted for the comparison of NPS pollutant loads among the three LULC conditions used and the sub-basins in each catchment. The results showed that the spatio-temporal variation of pollutant loads in almost all the catchments increased with changes in LULC condition as one moves from 1984 to 2013, with 2013 LULC condition found as the dominant in almost all cases. NPS pollutant loads among different LULC changes also increased with changes in LULC condition from 1984 to 2013. While urbanization was found to be the dominant LULC change with the highest pollutant load in all the catchments. Results from ANOVA reveals that statistically most significant (p < 0.05) pollutant loads were obtained from 2013 LULC conditions, while statistically least significant (p < 0.05) pollutant

Long-Term Hydrologic Impact Assessment of Non-point Source Pollution Measured Through Land Use/Land Cover (LULC) Changes in a Tropical Complex Catchment

NASA Astrophysics Data System (ADS)

Abdulkareem, Jabir Haruna; Sulaiman, Wan Nor Azmin; Pradhan, Biswajeet; Jamil, Nor Rohaizah

2018-05-01

The contribution of non-point source pollution (NPS) to the contamination of surface water is an issue of growing concern. Non-point source (NPS) pollutants are of various types and altered by several site-specific factors making them difficult to control due to complex uncertainties involve in their behavior. Kelantan River basin, Malaysia is a tropical catchment receiving heavy monsoon rainfall coupled with intense land use/land cover (LULC) changes making the area consistently flood prone thereby deteriorating the surface water quality in the area. This study was conducted to determine the spatio-temporal variation of NPS pollutant loads among different LULC changes and to establish a NPS pollutant loads relationships among LULC conditions and sub-basins in each catchment. Four pollutants parameters such as total suspended solids (TSS), total phosphorus (TP), total nitrogen (TN) and ammonia nitrogen (AN) were chosen with their corresponding event mean concentration values (EMC). Soil map and LULC change maps corresponding to 1984, 2002 and 2013 were used for the calculation of runoff and NPS pollutant loads using numeric integration in a GIS environment. Analysis of Variance (ANOVA) was conducted for the comparison of NPS pollutant loads among the three LULC conditions used and the sub-basins in each catchment. The results showed that the spatio-temporal variation of pollutant loads in almost all the catchments increased with changes in LULC condition as one moves from 1984 to 2013, with 2013 LULC condition found as the dominant in almost all cases. NPS pollutant loads among different LULC changes also increased with changes in LULC condition from 1984 to 2013. While urbanization was found to be the dominant LULC change with the highest pollutant load in all the catchments. Results from ANOVA reveals that statistically most significant ( p < 0.05) pollutant loads were obtained from 2013 LULC conditions, while statistically least significant ( p < 0.05) pollutant

Assimilation of GRACE Terrestrial Water Storage Data into a Land Surface Model

NASA Technical Reports Server (NTRS)

Reichle, Rolf H.; Zaitchik, Benjamin F.; Rodell, Matt

2008-01-01

The NASA Gravity Recovery and Climate Experiment (GRACE) system of satellites provides observations of large-scale, monthly terrestrial water storage (TWS) changes. In. this presentation we describe a land data assimilation system that ingests GRACE observations and show that the assimilation improves estimates of water storage and fluxes, as evaluated against independent measurements. The ensemble-based land data assimilation system uses a Kalman smoother approach along with the NASA Catchment Land Surface Model (CLSM). We assimilated GRACE-derived TWS anomalies for each of the four major sub-basins of the Mississippi into the Catchment Land Surface Model (CLSM). Compared with the open-loop (no assimilation) CLSM simulation, assimilation estimates of groundwater variability exhibited enhanced skill with respect to measured groundwater. Assimilation also significantly increased the correlation between simulated TWS and gauged river flow for all four sub-basins and for the Mississippi River basin itself. In addition, model performance was evaluated for watersheds smaller than the scale of GRACE observations, in the majority of cases, GRACE assimilation led to increased correlation between TWS estimates and gauged river flow, indicating that data assimilation has considerable potential to downscale GRACE data for hydrological applications. We will also describe how the output from the GRACE land data assimilation system is now being prepared for use in the North American Drought Monitor.

Land degradation assessment by geo-spatially modeling different soil erodibility equations in a semi-arid catchment.

PubMed

Saygın, Selen Deviren; Basaran, Mustafa; Ozcan, Ali Ugur; Dolarslan, Melda; Timur, Ozgur Burhan; Yilman, F Ebru; Erpul, Gunay

2011-09-01

Land degradation by soil erosion is one of the most serious problems and environmental issues in many ecosystems of arid and semi-arid regions. Especially, the disturbed areas have greater soil detachability and transportability capacity. Evaluation of land degradation in terms of soil erodibility, by using geostatistical modeling, is vital to protect and reclaim susceptible areas. Soil erodibility, described as the ability of soils to resist erosion, can be measured either directly under natural or simulated rainfall conditions, or indirectly estimated by empirical regression models. This study compares three empirical equations used to determine the soil erodibility factor of revised universal soil loss equation prediction technology based on their geospatial performances in the semi-arid catchment of the Saraykoy II Irrigation Dam located in Cankiri, Turkey. A total of 311 geo-referenced soil samples were collected with irregular intervals from the top soil layer (0-10 cm). Geostatistical analysis was performed with the point values of each equation to determine its spatial pattern. Results showed that equations that used soil organic matter in combination with the soil particle size better agreed with the variations in land use and topography of the catchment than the one using only the particle size distribution. It is recommended that the equations which dynamically integrate soil intrinsic properties with land use, topography, and its influences on the local microclimates, could be successfully used to geospatially determine sites highly susceptible to water erosion, and therefore, to select the agricultural and bio-engineering control measures needed.

Application of RUSLE method to assess the intensity of erosion due to land use changes in a small Polish Carpathians catchment

NASA Astrophysics Data System (ADS)

Bucała-Hrabia, Anna; Kijowska-Strugała, Małgorzata; Demczuk, Piotr

2017-04-01

Intensity of soil erosion is mainly depends on land cover changes, soil properties, heavy rainfalls and slope gradients. This study compared the influence of land use changes on soil erosion in the Homerka catchment, an area of 19.3 km2 located in the West Polish Carpathians, using GIS techniques such the Revised Universal Soil Loss Equation (RUSLE) method and cartographic materials from 1977, 1987, 1996 and 2009. RUSLE is the most common method which allows to predict the average size of the soil erosion due to specific soil properties, relief as well as rainfall erosivity factor. The period between 1977 and 2009 covers the transformation of the Polish economy from a communist system to a free-market economy after 1989. The analysis indicates an increase in the forest area of the Homerka catchment by 18.14% and a decrease of cultivated land by 82.64%. The grasslands did not change significantly in their area, however, their spatial pattern was very dynamic related to their reduction due to forest expansion and enlargement due to cultivated land abandonment.

Memory of the Lake Rotorua catchment - time lag of the water in the catchment and delayed arrival of contaminants from past land use activities

NASA Astrophysics Data System (ADS)

Morgenstern, Uwe; Daughney, Christopher J.; Stewart, Michael K.; McDonnell, Jeffrey J.

2013-04-01

, most of the water inflows into the lake are not yet fully representing the nitrate loading in their sub-catchments from current land use practises. These water inflows are still 'diluted' by pristine old water, but over time, the full amount of nitrate load will arrive at the lake. With the age distribution parameters, it is possible to predict the increase in nitrate load to the lake via the groundwater discharges. All sub-catchments have different mean transit times. The mean transit times are not necessarily correlated with observable hydrogeologic properties like hydraulic conductivity and catchment size. Without such age tracer data, it is therefore difficult to predict mean transit times (lag times, memory) of water transfer through catchments. References: Stewart, M.K., Morgenstern, U., McDonnell, J.J., Pfister, L. (2012). The 'hidden streamflow' challenge in catchment hydrology: A call to action for streamwater transit time analysis. Hydrol. Process. 26,2061-2066, Invited commentary. DOI: 10.1002/hyp.9262 Morgenstern, U., Stewart, M.K., and Stenger, R. (2010) Dating of streamwater using tritium in a post nuclear bomb pulse world: continuous variation of mean transit time with streamflow, Hydrol. Earth Syst. Sci, 14, 2289-2301

The response of sediment source and transfer dynamics to land use (change) in the Lake Manyara catchment

NASA Astrophysics Data System (ADS)

Wynants, Maarten; Munishi, Linus; Solomon, Henok; Grenfell, Michael; Taylor, Alex; Millward, Geoff; Boeckx, Pascal; Ndakidemi, Patrick; Gilvear, David; Blake, William

2017-04-01

The Lake Manyara basin in the East African Rift Region of Tanzania is considered to be an important driver for sustainable development in northern Tanzania in terms of biodiversity conservation, ecotourism, fisheries, pastoralism and (irrigation) agriculture. Besides local conservation, Lake Manyara National Park and its surroundings also have a vital function as a wildlife corridor connecting the Tarangire and Maasai steppe ecosystem with the entire northern Tanzania and Southern Kenya collective of national parks and ecosystems. However, driven by population pressure, increasing number of farmers are establishing agricultural operations in the catchment, causing a shift of the natural vegetation towards agricultural land. Furthermore, pastoralists with ever growing cattle stocks are roaming the grasslands, causing a decrease in soil structure due to overgrazing and compaction of the soil. We hypothesize that these processes increase the vulnerability to erosion, which presents a credible threat to ecosystem service provision, on the one hand the agricultural- and rangelands where loss of this finite resource threatens food security and people's livelihoods and on the other hand the water bodies, where siltation and eutrophication threatens the water quality and biodiversity. Knowledge of sediment source and transfer dynamics in the main tributaries of Lake Manyara and the response of these dynamics to land use (change) is critical to inform sustainable management policy decisions to maintain and enhance future food and water security. Using geochemical tracing techniques and Bayesian unmixing models we were able to attribute the lake sediment proportionally to its contributing tributaries. Furthermore, we were able to identify differences in erosion processes in different tributary systems using gamma spectrometry measurements of surface-elevated fallout radionuclides (137Cs and 210Pb). In our results we found that almost half of the sediment in the lake could be

Storylines of socio-economic and climatic drivers for land use and their hydrological impacts in alpine catchments - the STELLA project example

NASA Astrophysics Data System (ADS)

Strasser, Ulrich; Formayer, Herbert; Förster, Kristian; Marke, Thomas; Meißl, Gertraud; Schermer, Markus; Stotten, Friederike; Themessl, Matthias

2016-04-01

Future land use in Alpine catchments is controlled by the evolution of socio-economy and climate. Estimates of their coupled development should hence fulfill the principles of plausibility (be convincing) and consistency (be unambiguous). In the project STELLA, coupled future climate and land use scenarios are used as input in a hydrological modelling exercise with the physically-based, distributed water balance model WaSiM. The aim of the project is to quantify the effects of these two framing components on the future water cycle. The test site for the simulations is the catchment of the Brixentaler Ache in Tyrol/Austria (47.5°N, 322 km2). The so-called „storylines" of future coupled climate and forest/land use management, policy, social cooperation, tourism and economy have jointly been developed in an inter- and transdisciplinary assessment with local actors. The climate background is given by simulations for the A1B (temperature conditions like today in Merano/Italy, 46.7°N) and RCP 8.5 (temperature conditions like today in Bologna/Italy, 44.5°N) emission scenarios. These two climate scenarios were combined with three potential socio-economic developments („local"/„glocal"/ „superglobal"), each in a positive and in a negative specification. From these twelve storylines of coupled climate/land use future, a set of four storylines was selected to be used in transient hydrological modelling experiments. Historical simulations of the water balance for the test site reveal the pattern of land use being the most prominent factor for the spatial distribution of its components. A new prototype for a snow-canopy interaction simulation module provides explicit rates of intercepted and sublimated snow from the trees and stems of the different forest stands in the catchment. This new canopy module will be used to model the coupled climate/land use future storylines for the Brixental. The aim is to quantify the effects of climate change and land use on the water

Recent trends in water quality in an agricultural catchment in Eastern Scotland: elucidating the roles of hydrology and land use.

PubMed

Dunn, S M; Sample, J; Potts, J; Abel, C; Cook, Y; Taylor, C; Vinten, A J A

2014-07-01

Across the EU, programmes of measures have been introduced as part of river basin management planning as a means of tackling problems of diffuse pollution from agriculture. Evidence is required to demonstrate the effectiveness of these measures and with this overarching objective, monitoring of an agricultural catchment in Eastern Scotland was initiated in 2007. As a precursor to evaluating the effect of new management measures it is essential to understand how other factors, including hydrology and land use changes, could have influenced water quality. This study undertook an analysis of the trends in concentrations and loads of nitrate, soluble reactive phosphorus (SRP), suspended solids (SS) and turbidity measured at six points in the catchment over a six year period. The results identified both differing trends between determinands and differing trends occurring over varying spatial scales. The only direct relationships between land use and water quality that could be identified based on annual data was a positive link between arable cropping and nitrate concentrations. At the sub-catchment scale some temporal changes in land use and management explained short-term trends in nitrate but not in SRP. Lags in the system were identified due to soil adsorption, in-stream/loch processing and groundwater transport making the identification of cause and effect problematic. The results have implications for the demonstration of effectiveness of measures over the shorter term and the timescales of recovery from diffuse pollution. Longer term monitoring at small scales will be important in this regard.

Effects of River Discharge and Land Use and Land Cover (LULC) on Water Quality Dynamics in Migina Catchment, Rwanda

NASA Astrophysics Data System (ADS)

Uwimana, Abias; van Dam, Anne; Gettel, Gretchen; Bigirimana, Bonfils; Irvine, Kenneth

2017-09-01

Agricultural intensification may accelerate the loss of wetlands, increasing the concentrations of nutrients and sediments in downstream water bodies. The objective of this study was to assess the effects of land use and land cover and river discharge on water quality in the Migina catchment, southern Rwanda. Rainfall, discharge and water quality (total nitrogen, total phosphorus, total suspended solids, dissolved oxygen, conductivity, pH, and temperature) were measured in different periods from May 2009 to June 2013. In 2011, measurements were done at the outlets of 3 sub-catchments (Munyazi, Mukura and Akagera). Between May 2012 and May 2013 the measurements were done in 16 reaches of Munyazi dominated by rice, vegetables, grass/forest or ponds/reservoirs. Water quality was also measured during two rainfall events. Results showed seasonal trends in water quality associated with high water flows and farming activities. Across all sites, the total suspended solids related positively to discharge, increasing 2-8 times during high flow periods. Conductivity, temperature, dissolved oxygen, and pH decreased with increasing discharge, while total nitrogen and total phosphorus did not show a clear pattern. The total suspended solids concentrations were consistently higher downstream of reaches dominated by rice and vegetable farming. For total nitrogen and total phosphorus results were mixed, but suggesting higher concentration of total nitrogen and total phosphorus during the dry and early rainy (and farming) season, and then wash out during the rainy season, with subsequent dilution at the end of the rains. Rice and vegetable farming generate the transport of sediment as opposed to ponds/reservoir and grass/forest.

Historic First Landing of NASA's P-3B in Antarctica

NASA Image and Video Library

2014-01-03

NASA's first ever historic P-3B landing in McMurdo Station, Antarctica on the sea ice runway, which occurred on Nov. 16, 2013. It took the craft 5 days to reach Antarctica from the NASA Wallops Flight Facility in Wallops Island, Virginia. You can see the IceBridge Team waiting to greet the flight crew as they taxied for the very first time right up to the IceBridge team tents. Credit: NASA/Justin Miller/Indiana University NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

NASA F-15B #836 landing with Quiet Spike attached

NASA Image and Video Library

2006-10-03

NASA F-15B #836 landing with Quiet Spike attached. The project seeks to verify the structural integrity of the multi-segmented, articulating spike attachment designed to reduce and control a sonic boom.

Development of catchment research, with particular attention to Plynlimon and its forerunner, the East African catchments

NASA Astrophysics Data System (ADS)

Blackie, J. R.; Robinson, M.

2007-01-01

Dr J.S.G. McCulloch was deeply involved in the establishment of research catchments in East Africa and subsequently in the UK to investigate the hydrological consequences of changes in land use. Comparison of these studies provides an insight into how influential his inputs and direction have been in the progressive development of the philosophy, the instrumentation and the analytical techniques now employed in catchment research. There were great contrasts in the environments: tropical highland (high radiation, intense rainfall) vs. temperate maritime (low radiation and frontal storms), contrasting soils and vegetation types, as well as the differing social and economic pressures in developing and developed nations. Nevertheless, the underlying scientific philosophy was common to both, although techniques had to be modified according to local conditions. As specialised instrumentation and analytical techniques were developed for the UK catchments many were also integrated into the East African studies. Many lessons were learned in the course of these studies and from the experiences of other studies around the world. Overall, a rigorous scientific approach was developed with widespread applicability. Beyond the basics of catchment selection and the quantification of the main components of the catchment water balance, this involved initiating parallel process studies to provide information on specific aspects of catchment behaviour. This information could then form the basis for models capable of extrapolation from the observed time series to other periods/hydrological events and, ultimately, the capability of predicting the consequences of changes in catchment land management to other areas in a range of climates.

Seasonal scale water deficit forecasting in Africa and the Middle East using NASA's Land Information System (LIS)

NASA Astrophysics Data System (ADS)

Shukla, Shraddhanand; Arsenault, Kristi R.; Getirana, Augusto; Kumar, Sujay V.; Roningen, Jeanne; Zaitchik, Ben; McNally, Amy; Koster, Randal D.; Peters-Lidard, Christa

2017-04-01

Drought and water scarcity are among the important issues facing several regions within Africa and the Middle East. A seamless and effective monitoring and early warning system is needed by regional/national stakeholders. Such system should support a proactive drought management approach and mitigate the socio-economic losses up to the extent possible. In this presentation, we report on the ongoing development and validation of a seasonal scale water deficit forecasting system based on NASA's Land Information System (LIS) and seasonal climate forecasts. First, our presentation will focus on the implementation and validation of the LIS models used for drought and water availability monitoring in the region. The second part will focus on evaluating drought and water availability forecasts. Finally, details will be provided of our ongoing collaboration with end-user partners in the region (e.g., USAID's Famine Early Warning Systems Network, FEWS NET), on formulating meaningful early warning indicators, effective communication and seamless dissemination of the monitoring and forecasting products through NASA's web-services. The water deficit forecasting system thus far incorporates NOAA's Noah land surface model (LSM), version 3.3, the Variable Infiltration Capacity (VIC) model, version 4.12, NASA GMAO's Catchment LSM, and the Noah Multi-Physics (MP) LSM (the latter two incorporate prognostic water table schemes). In addition, the LSMs' surface and subsurface runoff are routed through the Hydrological Modeling and Analysis Platform (HyMAP) to simulate surface water dynamics. The LSMs are driven by NASA/GMAO's Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2), and the USGS and UCSB Climate Hazards Group InfraRed Precipitation with Station (CHIRPS) daily rainfall dataset. The LIS software framework integrates these forcing datasets and drives the four LSMs and HyMAP. The Land Verification Toolkit (LVT) is used for the evaluation of the

Global Hawk Aircraft Lands at NASA Wallops for Hurricane Mission

NASA Image and Video Library

2017-12-08

The first of two NASA Global Hawk unmanned aerial vehicles supporting the Hurricane and Severe Storm Sentinel (HS3) mission landed at 7:39 a.m. today, Aug. 14, 2013, at NASA's Wallops Flight Facility, Wallops Island, Va. During August and September, NASA will fly the two Global Hawks over the Atlantic Ocean to study tropical storms and the processes that underlie hurricane formation and intensification. The aircraft are equipped with instruments to survey the overall environment of the storms and peer into the inner core of hurricanes to study their structure and processes. For more information, visit: www.nasa.gov/HS3. Photo Credit: NASA Wallops Keith Koehler NASA Wallops Flight Facility NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

NASAs B377SGT Super Guppy Turbine Cargo Airplane lands at Moffett Field at NASA Ames.

NASA Image and Video Library

2016-01-08

NASA N941NA Superguppy lands at the Moffett Field. Cargo is loaded into the Super Guppy when the aircraft's "fold-away" nose rotates 110 degrees to the left, allowing unobstructed access to the 25 foot diameter fuselage.

Nasa's Land Remote Sensing Plans for the 1980's

NASA Technical Reports Server (NTRS)

Higg, H. C.; Butera, K. M.; Settle, M.

1985-01-01

Research since the launch of LANDSAT-1 has been primarily directed to the development of analysis techniques and to the conduct of applications studies designed to address resource information needs in the United States and in many other countries. The current measurement capabilities represented by MSS, TM, and SIR-A and B, coupled with the present level of remote sensing understanding and the state of knowledge in the discipline earth sciences, form the foundation for NASA's Land Processes Program. Science issues to be systematically addressed include: energy balance, hydrologic cycle, biogeochemical cycles, biological productivity, rock cycle, landscape development, geological and botanical associations, and land surface inventory, monitoring, and modeling. A global perspective is required for using remote sensing technology for problem solving or applications context. A successful model for this kind of activity involves joint research with a user entity where the user provides a test site and ground truth and NASA provides the remote sensing techniques to be tested.

Catchment scale afforestation for mitigating flooding

NASA Astrophysics Data System (ADS)

Barnes, Mhari; Quinn, Paul; Bathurst, James; Birkinshaw, Stephen

2016-04-01

After the 2013-14 floods in the UK there were calls to 'forest the uplands' as a solution to reducing flood risk across the nation. At present, 1 in 6 homes in Britain are at risk of flooding and current EU legislation demands a sustainable, 'nature-based solution'. However, the role of forests as a natural flood management technique remains highly controversial, due to a distinct lack of robust evidence into its effectiveness in reducing flood risk during extreme events. SHETRAN, physically-based spatially-distributed hydrological models of the Irthing catchment and Wark forest sub-catchments (northern England) have been developed in order to test the hypothesis of the effect trees have on flood magnitude. The advanced physically-based models have been designed to model scale-related responses from 1, through 10, to 100km2, a first study of the extent to which afforestation and woody debris runoff attenuation features (RAFs) may help to mitigate floods at the full catchment scale (100-1000 km2) and on a national basis. Furthermore, there is a need to analyse the extent to which land management practices, and the installation of nature-based RAFs, such as woody debris dams, in headwater catchments can attenuate flood-wave movement, and potentially reduce downstream flood risk. The impacts of riparian planting and the benefits of adding large woody debris of several designs and on differing sizes of channels has also been simulated using advanced hydrodynamic (HiPIMS) and hydrological modelling (SHETRAN). With the aim of determining the effect forestry may have on flood frequency, 1000 years of generated rainfall data representative of current conditions has been used to determine the difference between current land-cover, different distributions of forest cover and the defining scenarios - complete forest removal and complete afforestation of the catchment. The simulations show the percentage of forestry required to have a significant impact on mitigating

Field-based study of connectivity in an agricultural catchment

NASA Astrophysics Data System (ADS)

Lexartza-Artza, I.; Wainwright, J.

2009-12-01

Field-based studies of hydrological connectivity can provide context-specific knowledge that might both help understand dynamic complex systems and contribute to other synthetic or modelling approaches. The importance of such an understanding of catchment processes and also of the knowledge of catchment connections with water bodies and the changes of concentration with scale for Integrated Catchment Management has been increasingly emphasized. To provide a holistic understanding, approaches to the study of connectivity need to include both structural and functional aspects of the system and must consider the processes taking place within and across different temporal and spatial scales. A semi-quantitative nested approach has been used to investigate connectivity and study the interactions and feedbacks between the factors influencing transfer processes in the Ingbirchworth Catchment, in the uplands of the River Don, England. A series of reconnaissance techniques have been combined with monitoring of aspects such as rainfall, runoff, sediment transfer and soil-moisture distribution from plot to catchment scale and with consideration of linkages between land and water bodies. The temporal aspect has also been considered, with a special focus on the temporal distribution of events and the influence of longer term catchment changes such as those in land use and management practices. A variability of responses has been observed in relation to the characteristics of events, land use and scale of observation, with elements traditionally considered as limiting or enhancing connectivity responding differently under changing conditions. Sediment redistribution, reshaping of structure and consequent reinforcing loops can be observed across all land uses and landscape units, but the relevance it terms of effective connectivity of highly connected patches varies as the scale is increased. The knowledge acquired can contribute to recognise emerging processes significant for

Analysis of land use changes over the last 200 years in the catchment of Lake Czechowskie (Pomerania, northern Poland)

NASA Astrophysics Data System (ADS)

Tyszkowski, Sebastian; Kaczmarek, Halina

2014-05-01

Changes in land cover in the catchment area are, beside climate change, some of the major factors affecting sedimentation processes in lakes. With increasing human impact, changes in land cover no longer depend primarily on climate. In relation to research on sediments of Lake Czechowskie in Pomeranian Province in North Poland, land use changes over the last 200 years were analysed, with particular reference to deforestation or afforestation. The study area was the lake catchment, which covers nearly 20 km2. The analysis was based on archival and contemporary cartographic and photogrammetric materials, georeferenced and rectified using ArcGIS software. The following materials were used: Schrötter-Engelhart, Karte von Ost-Preussen nebst Preussisch Litthauen und West-Preussen nebst dem Netzdistrict, 1:50 000, section 92, 93, 1796-1802; Map Messtishchblatt, 1:25000, sheet Czarnen, (mapping conducted in 1874), 1932; Map WIG (Military Geographical Institute - Wojskowy Instytut Geograficzny), 1:25000, sheet Osowo, (mapping conducted in 1929-31), 1933; aerial photos 1:13000, 1964, 1969; 1:25000, 1987; 1:26000, 1997; aerial ortophotomap , 1:5000, 2010. Today, over 60% of the catchment of Lake Czechowskie is covered with forests, dominated by planted Scots pine (Pinus sylvestris), while the remaining areas are used for agricultural purposes or are built up. The first cartographic materials indicate that in the late 18th c., forest covered almost 50% of the catchment surface. By the year 1870, there was a significant reduction in the forested area, as its contribution fell to 40%. Deforestation took place mainly between the main villages. In the 1920s the forest cover increased to 44%. Today, almost the entire lake is surrounded by forest and a wetland belt (at least 0.5 km wide). Deforestation in the catchment should not be attributed solely to logging because the area of Tuchola Forests (Bory Tucholskie) was repeatedly affected by natural disasters. In the 19th c. these

National Climate Assessment - Land Data Assimilation System (NCA-LDAS) Data at NASA GES DISC

NASA Technical Reports Server (NTRS)

Rui, Hualan; Teng, Bill; Vollmer, Bruce; Jasinski, Michael; Mocko, David; Kempler, Steven

2016-01-01

As part of NASA's active participation in the Interagency National Climate Assessment (NCA) program, the Goddard Space Flight Center's Hydrological Sciences Laboratory (HSL) is supporting an Integrated Terrestrial Water Analysis, by using NASA's Land Information System (LIS) and Land Data Assimilation System (LDAS) capabilities. To maximize the benefit of the NCA-LDAS, on completion of planned model runs and uncertainty analysis, NASA will provide open access to all NCA-LDAS components, including input data, output fields, and indicator data, to other NCA-teams and the general public. The NCA-LDAS data will be archived at the NASA GES DISC (Goddard Earth Sciences Data and Information Services Center) and can be accessed via direct ftp, THREDDS, Mirador search and download, and Giovanni visualization and analysis system.

Insights into the history and timing of post-European land use disturbance on sedimentation rates in catchments draining to the Great Barrier Reef.

PubMed

Bartley, Rebecca; Thompson, Chris; Croke, Jacky; Pietsch, Tim; Baker, Brett; Hughes, Kate; Kinsey-Henderson, Anne

2018-06-01

Sediment runoff has been cited as a major contributor to the declining health of the Great Barrier Reef (GBR), however, climate and land use drivers have not been jointly evaluated. This study used alluvial archives from fluvial benches in two tributaries of the Upper Burdekin catchment together with the best available land use history and climate proxy records to provide insights into the timing of depositional events in this region over the past 500 years. This study suggests that mining and the increased runoff variability in the latter half of the nineteenth century are the likely sources of the original excess sediment that was used to build the bench features in these catchments. Grazing also contributed to increased bench sedimentation prior to 1900, however, the contribution of grazing was likely more significant in the second half of the 20th century, and continues to be a dominant land use contributor today. Copyright © 2018 Elsevier Ltd. All rights reserved.

Land Management, River Restoration and the Water Framework Directive

NASA Astrophysics Data System (ADS)

Smith, Ben; Clifford, Nicholas

2014-05-01

The influence of catchment land-use on river ecosystems is well established, with negative changes in hydrology, sediment supply and pollutants causing widespread degradation in modified catchments across Europe. The strength of relationship found between different land-use types and impacts on river systems varies from study to study as a result of issues around data quality, scale, study design and the interaction of stressors at multiple scales. Analysis of large-scale datasets can provide important information about the way that catchments pressures affect WFD objectives at a national scale. Comparisons of relationships between land-use and WFD status in different types of catchment within the UK allow an assessment of catchment sensitivity and analysis of the catchment characteristics which influence these relationships. The results suggest prioritising catchments at or near land-use thresholds, or targeting waterbodies with limited land-use pressures but which are failing to achieve GES or GEP. This paper uses UK datasets on land cover and WFD waterbody status to examine how catchment land-use impacts on WFD status and to evaluate opportunities to achieve Good Ecological Status or Good Ecological Potential. Agricultural and urban land-use are shown to have different types of relationship with respect to the likelihood of achieving Good Ecological Status, and with clear threshold effects apparent for urban land-use in the catchment. Broad-scale analysis shows the influence of different sized buffer strips in mitigating the negative effects of different types of land-cover, and reinforces the positive effects of riparian woodland on river ecosystems and their potential under the WFD.

Urbanization and agriculture increase exports and differentially alter elemental stoichiometry of dissolved organic matter (DOM) from tropical catchments.

PubMed

Gücker, Björn; Silva, Ricky C S; Graeber, Daniel; Monteiro, José A F; Boëchat, Iola G

2016-04-15

Many tropical biomes are threatened by rapid land-use change, but its catchment-wide biogeochemical effects are poorly understood. The few previous studies on DOM in tropical catchments suggest that deforestation and subsequent land use increase stream water dissolved organic carbon (DOC) concentrations, but consistent effects on DOM elemental stoichiometry have not yet been reported. Here, we studied stream water DOC concentrations, catchment DOC exports, and DOM elemental stoichiometry in 20 tropical catchments at the Cerrado-Atlantic rainforest transition, dominated by natural vegetation, pasture, intensive agriculture, and urban land cover. Streams draining pasture could be distinguished from those draining natural catchments by their lower DOC concentrations, with lower DOM C:N and C:P ratios. Catchments with intensive agriculture had higher DOC exports and lower DOM C:P ratios than natural catchments. Finally, with the highest DOC concentrations and exports, as well as the highest DOM C:P and N:P ratios, but the lowest C:N ratios among all land-use types, urbanized catchments had the strongest effects on catchment DOM. Thus, urbanization may have alleviated N limitation of heterotrophic DOM decomposition, but increased P limitation. Land use-especially urbanization-also affected the seasonality of catchment biogeochemistry. While natural catchments exhibited high DOC exports and concentrations, with high DOM C:P ratios in the rainy season only, urbanized catchments had high values in these variables throughout the year. Our results suggest that urbanization and pastoral land use exerted the strongest impacts on DOM biogeochemistry in the investigated tropical catchments and should thus be important targets for management and mitigation efforts. Copyright © 2016 Elsevier B.V. All rights reserved.

Rainfall-runoff modelling of the Okavango River catchment to assess impacts of land use change on runoff and downstream ecosystems

NASA Astrophysics Data System (ADS)

Milzow, Christian; Bauer-Gottwein, Peter

2010-05-01

The competition between human water use and ecosystem water use is one of the major challenges for water resources management at the global scale. We analyse the situation for the Okavango River basin of southern Africa. The Okavango River is representative for many large rivers throughout the developing world in that it is ungauged and poorly studied. The Okavango basin - spanning over Angola, Namibia and Botswana - represents a multi-objective problem in an international setting. Economic benefits of agricultural development and conservation of ecosystem services call for opposed actions. A semi-distributed rainfall-runoff model of the Okavango catchment is set up using the Soil and Water Assessment Tool (SWAT). The model is sufficiently physically based to simulate the impact on runoff of extent of agricultural use, crop types and management practices. Precipitation and temperature inputs are taken from datasets covering large parts of the globe. The methodology can thus easily be applied for other ungauged catchments. For temperature we use the ERA-Interim reanalysis product of the European Centre for Medium-Range Weather Forecasts and for precipitation the Famine Early Warning Systems Network data (FEWS-Net). Tropical Rainfall Measurement Mission (TRMM) data resulted in poor model performance compared to the FEWS-Net data. Presently, the upstream catchment in Angola is largely pristine and agriculture is basically restricted to dry land subsistence farming. But economic growth in Angola is likely to result in agricultural development and consequent impacts on catchment runoff. Land use scenarios that are simulated include large scale irrigated agriculture with water extractions from the river and the shallow aquifer. Climate change impacts are also studied and compared to land use change impacts. The downstream part of the basin consists of the large Okavango Wetlands, which are a biodiversity hotspot of global importance and, through tourism, an important

Land use change impacts on discharge analysis using SWAT model at Ciherang Pondok DAM catchment area

NASA Astrophysics Data System (ADS)

Utamahadi, M. A.; Pandjaitan, N. H.; Rau, M. I.

2018-05-01

The prompt increase of population influenced the requirement for new regions to fulfill people’s primary needs. Its increased land use change and caused many impacts on the environment, including watersheds as well. Ciherang Pondok DAM catchment area is part of Cisadane watershed and was selected as the research area. This research aimed to analyse the water supply and water discharge change caused by the Urban Planning (RTRW) in 2020. The analysis was conducted using soil and water assessment tools (SWAT) model. Stages of this research were catchment area delineation, HRU identification, calibration and validation of models, and prediction of discharge and water demand. The result showed that RTRW of 2020 increased the maximum discharge of 1.6 m3/s and decreased the minimum discharge of 0.01 m3/s, hence the maximum and minimum discharge ratio increased 0.26% from 2016. Output discharge in 2020 at Ciherang Pondok Dam Catchment Area was classified as well, with discharge of 6.72 – 126.2 m3/s, and could fulfil water demand. For the best result, it is better to use climate data from weather stations inside the study area and it is required an improvement in data archiving system.

Spatio-temporal patterns of nutrient fluxes as a function of hydrologic variability, land cover and fires in coastal California catchments

NASA Astrophysics Data System (ADS)

Aguilera, R.; Melack, J. M.; Goodridge, B. M.

2016-12-01

Given the projections of increased urbanization of coastal areas and severity of extreme events related to hydrological variability and wildfires, a better understanding of material export within and from streams under a wide range of environmental conditions remains a fundamental concern. In semiarid regions, ecosystem processes can be hydrologically decoupled for more than 6 months per year, and abrupt shifts from dry-to-wet soil conditions can produce pulsed biogeochemical signals, such as elevated hydrologic export. In our study in the coastal catchments along the Santa Barbara Channel, California, the intensive sampling throughout storm hydrographs required by the episodic nature of runoff, the multi-year periods that include years with very low precipitation and others with large events, the sequence of fires in several watersheds, and the variety of land uses and land covers represented, allowed a multivariate analysis of factors influencing nutrient fluxes in semiarid catchments. Nutrient flux estimates were obtained for 21 sites ranging from 3 to 14 years of sampling (between water years 2002-2015). Annual nitrogen fluxes (NH4, NO3 and DON) per unit area (mol ha-1 y-1) for each site varied over six orders of magnitude. Phosphate fluxes exhibited a single-order-of-magnitude difference among the catchments. Highest annual fluxes were observed in 2005, a wet year, for all nutrients and across sites. Nutrient fluxes following wildfire events within our study period in 13 sites (10-80% burned upstream catchment area) were also among the highest observed, particularly in the case of ammonium. During water years 2012-2015, drought conditions and the subsequent decrease in storm runoff were associated with the lowest fluxes for all nutrients.

Catchment Classification: Connecting Climate, Structure and Function

NASA Astrophysics Data System (ADS)

Sawicz, K. A.; Wagener, T.; Sivapalan, M.; Troch, P. A.; Carrillo, G. A.

2010-12-01

Hydrology does not yet possess a generally accepted catchment classification framework. Such a classification framework needs to: [1] give names to things, i.e. the main classification step, [2] permit transfer of information, i.e. regionalization of information, [3] permit development of generalizations, i.e. to develop new theory, and [4] provide a first order environmental change impact assessment, i.e., the hydrologic implications of climate, land use and land cover change. One strategy is to create a catchment classification framework based on the notion of catchment functions (partitioning, storage, and release). Results of an empirical study presented here connects climate and structure to catchment function (in the form of select hydrologic signatures), based on analyzing over 300 US catchments. Initial results indicate a wide assortment of signature relationships with properties of climate, geology, and vegetation. The uncertainty in the different regionalized signatures varies widely, and therefore there is variability in the robustness of classifying ungauged basins. This research provides insight into the controls of hydrologic behavior of a catchment, and enables a classification framework applicable to gauged and ungauged across the study domain. This study sheds light on what we can expect to achieve in mapping climate, structure and function in a top-down manner. Results of this study complement work done using a bottom-up physically-based modeling framework to generalize this approach (Carrillo et al., this session).

Effect of land use and hydrological processes on Escherichia coli concentrations in streams of tropical, humid headwater catchments

PubMed Central

Rochelle-Newall, Emma J.; Ribolzi, Olivier; Viguier, Marion; Thammahacksa, Chanthamousone; Silvera, Norbert; Latsachack, Keooudone; Dinh, Rinh Pham; Naporn, Piyapong; Sy, Hai Tran; Soulileuth, Bounsamay; Hmaimum, Nikom; Sisouvanh, Pem; Robain, Henri; Janeau, Jean-Louis; Valentin, Christian; Boithias, Laurie; Pierret, Alain

2016-01-01

Lack of access to clean water and adequate sanitation continues to be a major brake on development. Here we present the results of a 12-month investigation into the dynamics of Escherichia coli, a commonly used indicator of faecal contamination in water supplies, in three small, rural catchments in Laos, Thailand and Vietnam. We show that land use and hydrology are major controlling factors of E. coli concentrations in streamwater and that the relative importance of these two factors varies between the dry and wet seasons. In all three catchments, the highest concentrations were observed during the wet season when storm events and overland flow were highest. However, smaller peaks of E. coli concentration were also observed during the dry season. These latter correspond to periods of intense farming activities and small, episodic rain events. Furthermore, vegetation type, through land use and soil surface crusting, combined with mammalian presence play an important role in determining E. coli loads in the streams. Finally, sampling during stormflow revealed the importance of having appropriate sampling protocols if information on maximum contamination levels is required as grab sampling at a fixed time step may miss important peaks in E. coli numbers. PMID:27604854

Effect of land use and hydrological processes on Escherichia coli concentrations in streams of tropical, humid headwater catchments.

PubMed

Rochelle-Newall, Emma J; Ribolzi, Olivier; Viguier, Marion; Thammahacksa, Chanthamousone; Silvera, Norbert; Latsachack, Keooudone; Dinh, Rinh Pham; Naporn, Piyapong; Sy, Hai Tran; Soulileuth, Bounsamay; Hmaimum, Nikom; Sisouvanh, Pem; Robain, Henri; Janeau, Jean-Louis; Valentin, Christian; Boithias, Laurie; Pierret, Alain

2016-09-08

Lack of access to clean water and adequate sanitation continues to be a major brake on development. Here we present the results of a 12-month investigation into the dynamics of Escherichia coli, a commonly used indicator of faecal contamination in water supplies, in three small, rural catchments in Laos, Thailand and Vietnam. We show that land use and hydrology are major controlling factors of E. coli concentrations in streamwater and that the relative importance of these two factors varies between the dry and wet seasons. In all three catchments, the highest concentrations were observed during the wet season when storm events and overland flow were highest. However, smaller peaks of E. coli concentration were also observed during the dry season. These latter correspond to periods of intense farming activities and small, episodic rain events. Furthermore, vegetation type, through land use and soil surface crusting, combined with mammalian presence play an important role in determining E. coli loads in the streams. Finally, sampling during stormflow revealed the importance of having appropriate sampling protocols if information on maximum contamination levels is required as grab sampling at a fixed time step may miss important peaks in E. coli numbers.

Effect of land use and hydrological processes on Escherichia coli concentrations in streams of tropical, humid headwater catchments

NASA Astrophysics Data System (ADS)

Rochelle-Newall, Emma J.; Ribolzi, Olivier; Viguier, Marion; Thammahacksa, Chanthamousone; Silvera, Norbert; Latsachack, Keooudone; Dinh, Rinh Pham; Naporn, Piyapong; Sy, Hai Tran; Soulileuth, Bounsamay; Hmaimum, Nikom; Sisouvanh, Pem; Robain, Henri; Janeau, Jean-Louis; Valentin, Christian; Boithias, Laurie; Pierret, Alain

2016-09-01

Lack of access to clean water and adequate sanitation continues to be a major brake on development. Here we present the results of a 12-month investigation into the dynamics of Escherichia coli, a commonly used indicator of faecal contamination in water supplies, in three small, rural catchments in Laos, Thailand and Vietnam. We show that land use and hydrology are major controlling factors of E. coli concentrations in streamwater and that the relative importance of these two factors varies between the dry and wet seasons. In all three catchments, the highest concentrations were observed during the wet season when storm events and overland flow were highest. However, smaller peaks of E. coli concentration were also observed during the dry season. These latter correspond to periods of intense farming activities and small, episodic rain events. Furthermore, vegetation type, through land use and soil surface crusting, combined with mammalian presence play an important role in determining E. coli loads in the streams. Finally, sampling during stormflow revealed the importance of having appropriate sampling protocols if information on maximum contamination levels is required as grab sampling at a fixed time step may miss important peaks in E. coli numbers.

The Effect of Subsurface Parameterizations on Modeled Flows in the Catchment Land Surface Model, Fortuna 2.5

NASA Astrophysics Data System (ADS)

Roningen, J. M.; Eylander, J. B.

2014-12-01

Groundwater use and management is subject to economic, legal, technical, and informational constraints and incentives at a variety of spatial and temporal scales. Planned and de facto management practices influenced by tax structures, legal frameworks, and agricultural and trade policies that vary at the country scale may have medium- and long-term effects on the ability of a region to support current and projected agricultural and industrial development. USACE is working to explore and develop global-scale, physically-based frameworks to serve as a baseline for hydrologic policy comparisons and consequence assessment, and such frameworks must include a reasonable representation of groundwater systems. To this end, we demonstrate the effects of different subsurface parameterizations, scaling, and meteorological forcings on surface and subsurface components of the Catchment Land Surface Model Fortuna v2.5 (Koster et al. 2000). We use the Land Information System 7 (Kumar et al. 2006) to process model runs using meteorological components of the Air Force Weather Agency's AGRMET forcing data from 2006 through 2011. Seasonal patterns and trends are examined in areas of the Upper Nile basin, northern China, and the Mississippi Valley. We also discuss the relevance of the model's representation of the catchment deficit with respect to local hydrogeologic structures.

Tropical montane forest conversion affects spatial and temporal nitrogen dynamics in Kenyan headwater catchment

NASA Astrophysics Data System (ADS)

Jacobs, Suzanne; Weeser, Björn; Breuer, Lutz; Butterbach-Bahl, Klaus; Guzha, Alphonce; Rufino, Mariana

2017-04-01

Deforestation and land use change (LUC) are often stated as major contributors to changes in water quality, although other catchment characteristics such as topography, geology and climate can also play a role. Understanding how stream water chemistry is affected by LUC is essential for sustainable water management and land use planning. However, there is often a lack of reliable data, especially in less studied regions such as East Africa. This study focuses on three sub-catchments (27-36 km2) with different land use types (natural forest, smallholder agriculture and tea/tree plantations) nested in a 1023 km2 headwater catchment in the Mau Forest Complex, Kenya's largest closed-canopy indigenous tropical montane forest. In the past decades approx. 25% of the natural forest was lost due to land use change. We studied seasonal, diurnal and spatial patterns of total dissolved nitrogen (TDN), nitrate (NO3-N) and dissolved organic nitrogen (DON) using a combination of high-resolution in-situ measurements, bi-weekly stream water samples and spatial sampling campaigns. Multiple linear regression analysis of the spatial data indicates that land use shows a strong influence on TDN and nitrate, while DON is more influenced by precipitation. Highest TDN and nitrate concentrations are found in tea plantations, followed by smallholder agriculture and natural forest. This ranking does not change throughout the year, though concentrations of TDN and nitrate are respectively 27.6 and 25.4% lower in all catchments during the dry season. Maximum Overlap Discrete Wavelet Transform (MODWT) analysis of the high resolution nitrate data revealed a seasonal effect on diurnal patterns in the natural forest catchment, where the daily peak shifts from early morning in the wet season to mid-afternoon in the dry season. The smallholder and tea catchment do not exhibit clear diurnal patterns. The results suggest that land use affects dissolved nitrogen concentrations, leading to higher N

Land Use Change and Land Degradation in Southeastern Mediterranean Spain

NASA Astrophysics Data System (ADS)

Symeonakis, Elias; Calvo-Cases, Adolfo; Arnau-Rosalen, Eva

2007-07-01

The magnitude of the environmental and social consequences of soil erosion and land degradation in semiarid areas of the Mediterranean region has long been recognized and studied. This paper investigates the interrelationship between land use/cover (LULC) changes and land degradation using remotely sensed and ancillary data for southeastern Spain. The area of study, the Xaló River catchment situated in the north of the Alicante Province, has been subjected to a number of LULC changes during the second half of the 20th century such as agricultural abandonment, forest fires, and tourist development. Aerial photographs dating back to 1956 were used for the delineation of historic LULC types; Landsat ETM+ data were used for the analysis and mapping of current conditions. Two important indicators of land degradation, namely, susceptibility to surface runoff and soil erosion, were estimated for the two dates using easily parametrizable models. The comparison of 1956 to 2000 conditions shows an overall “recuperating” trend over the catchment and increased susceptibility to soil erosion only in 3% of the catchment area. The results also identify potential degradation hot-spots where mitigation measures should be taken to prevent further degradation. The readily implemented methodology, based on modest data requirements demonstrated by this study, is a useful tool for catchment to regional scale land use change and land degradation studies and strategic planning for environmental management.

Land use change and land degradation in southeastern Mediterranean Spain.

PubMed

Symeonakis, Elias; Calvo-Cases, Adolfo; Arnau-Rosalen, Eva

2007-07-01

The magnitude of the environmental and social consequences of soil erosion and land degradation in semiarid areas of the Mediterranean region has long been recognized and studied. This paper investigates the interrelationship between land use/cover (LULC) changes and land degradation using remotely sensed and ancillary data for southeastern Spain. The area of study, the Xaló River catchment situated in the north of the Alicante Province, has been subjected to a number of LULC changes during the second half of the 20th century such as agricultural abandonment, forest fires, and tourist development. Aerial photographs dating back to 1956 were used for the delineation of historic LULC types; Landsat ETM+ data were used for the analysis and mapping of current conditions. Two important indicators of land degradation, namely, susceptibility to surface runoff and soil erosion, were estimated for the two dates using easily parametrizable models. The comparison of 1956 to 2000 conditions shows an overall "recuperating" trend over the catchment and increased susceptibility to soil erosion only in 3% of the catchment area. The results also identify potential degradation hot-spots where mitigation measures should be taken to prevent further degradation. The readily implemented methodology, based on modest data requirements demonstrated by this study, is a useful tool for catchment to regional scale land use change and land degradation studies and strategic planning for environmental management.

Water and salt balance modelling to predict the effects of land-use changes in forested catchments. 3. The large catchment model

NASA Astrophysics Data System (ADS)

Sivapalan, Murugesu; Viney, Neil R.; Jeevaraj, Charles G.

1996-03-01

This paper presents an application of a long-term, large catchment-scale, water balance model developed to predict the effects of forest clearing in the south-west of Western Australia. The conceptual model simulates the basic daily water balance fluxes in forested catchments before and after clearing. The large catchment is divided into a number of sub-catchments (1-5 km2 in area), which are taken as the fundamental building blocks of the large catchment model. The responses of the individual subcatchments to rainfall and pan evaporation are conceptualized in terms of three inter-dependent subsurface stores A, B and F, which are considered to represent the moisture states of the subcatchments. Details of the subcatchment-scale water balance model have been presented earlier in Part 1 of this series of papers. The response of any subcatchment is a function of its local moisture state, as measured by the local values of the stores. The variations of the initial values of the stores among the subcatchments are described in the large catchment model through simple, linear equations involving a number of similarity indices representing topography, mean annual rainfall and level of forest clearing.The model is applied to the Conjurunup catchment, a medium-sized (39·6 km2) catchment in the south-west of Western Australia. The catchment has been heterogeneously (in space and time) cleared for bauxite mining and subsequently rehabilitated. For this application, the catchment is divided into 11 subcatchments. The model parameters are estimated by calibration, by comparing observed and predicted runoff values, over a 18 year period, for the large catchment and two of the subcatchments. Excellent fits are obtained.

Storylines of combined land use and climatic drivers and their hydrological impacts in an alpine catchment (Brixental/Austria)

NASA Astrophysics Data System (ADS)

Strasser, Ulrich; Förster, Kristian; Meissl, Gertraud; Marke, Thomas; Schermer, Markus; Stotten, Rike; Formayer, Herbert; Themessl, Matthias

2017-04-01

We present a numerical modelling experiment with storylines of coupled land use and climate evolution as input in the physically-based, distributed water balance model WaSiM. The aim is to quantify the effects of these two framing components on the future water cycle. The test site for the simulations is the catchment of the Brixentaler Ache in Tyrol/Austria (47.5°N, 322 km2). The climatic background is defined by simulations for the A1B and RCP 8.5 emission scenarios until 2050. These two climate projections were combined with three future land use developments for forest management, developed in an inter- and transdisciplinary assessment with local actors using plausible and consisent projections for forest management, policy, social cooperation, tourism and economy: (i) Ecological adaptation: The forest management consequently applies the political guidelines, and the forest cover is dominated by an ecological, place-adapted mixed cultivation with a harmonious age structure. (ii) Economical overexploitation and wildness: The increase in efficiency, cost reduction and short term results are in focus of the forest management. (iii) Withdrawal and wildness: Cultivation in general is decreasing, and the forest becomes vulnerable against natural hazards. A new module for snow-canopy interaction simulation, providing explicit rates of intercepted and sublimated snow from the trees and stems of the different forest stands, has been implemented in WaSiM. The new version of the model is used to model the coupled future climate/land use storylines for the Brixental. Results show the effects of climate change and land use on the water balance and streamflow in the catchment.

Rainfall and runoff quantity and quality characteristics of four urban land-use catchments in Fresno, California, October 1981 to April 1983

USGS Publications Warehouse

Oltmann, Richard N.; Shulters, Michael V.

1989-01-01

Rainfall and runoff quantity and quality were monitored for industrial, single-dwelling residential, multiple-dwelling residential, and commercial land-use catchments during the 1981-82 and 1982-83 rain seasons. Storm-composite rainfall and discrete run6ff samples were analyzed for numerous inorganic, biological, physical, and organic constituents. Atmospheric dry-deposition and street-surface particulate samples also were collected and analyzed. With the exception of the industrial catchment, the highest runoff concentrations for most constituents occurred during the initial storm runoff and then decreased throughout the remainder of the storm, independent of hydraulic conditions. Metal concentrations were high during initial runoff, but also increased as flow increased. Constituent concentrations for the industrial catchment fluctuated greatly during storms. Statistical tests showed higher ammonia plus organic nitrogen, ammonia, pH, and phenol concentrations in rainfall at the industrial site than at the single-dwelling residential and laboratory sites. Statistical testing of runoff quality data showed higher concentrations for the industrial catchment than for the two residential and commercial catchments for most constituents. Total recoverable lead was one of the few constituents that had lower concentrations for the industrial catchment than for the other three catchments. The two residential catchments showed no significant difference in runoff concentrations for 50 of the 57 constituents used in the statistical analysis. The commercial catchment runoff concentrations for most constituents generally were similar to the residential catchments. Although constituent concentrations generally were higher for the industrial catchment than for the commercial catchment, constituent storm loads from the commercial catchment were similar to the industrial catchment because of the greater runoff volume from the highly impervious commercial catchment. Between 10 and 50

Decreasing soil erosion rates with evolving land-use techniques in a central European catchment

NASA Astrophysics Data System (ADS)

Larsen, Annegret; Heckmann, Tobias; Hans-Rudolf, Bork; Alexander, Fuelling

2015-04-01

Agricultural societies around the world have caused accelerated soil erosion. Soil erosion and a decrease in soil fertility may also have caused the abandonment of entire landscapes and the collapse of civilizations. In central Europe, Medieval land-use is thought to have lead to the largest loss of top soil in history, which in turn lead to a malnutrition of the population and abandonment of agricultural land. However, this might be only part of the picture, as people are also able to adapt to changing environmental conditions, including the type of land-use they adopt. Within a catchment in the central European mountain belt, we were able to distinguish the evolution between three main types of land-use techniques between ~ 900 AD and 1950 AD: horticulture, agriculture and shifting cultivation. We were able to relate these techniques with different soil erosion rates, which differ by an order of magnitude, ranging from 0.83 ± 0.09 mm/yr to 1.62 ± 0.17 mm/yr. Using high-resolution surface data and chrono-stratigraphical methods in combination with soil charcoal analysis, we were able to reconstruct past land-use techniques on a local scale. This illustrates that less erosive and more sustainable techniques were developed through time, and hypothesize that people were able to adapt to the less favorable environmental conditions by changing the cultivation techniques. Although cultural adaptation to changing environmental conditions has been extensively discussed, this study is able to quantitatively demonstrate improved soil management with evolving land-use in central Europe.

Expanding NASA's Land, Atmosphere Near real-time Capability for EOS

NASA Astrophysics Data System (ADS)

Davies, D.; Michael, K.; Masuoka, E.; Ye, G.; Schmaltz, J. E.; Harrison, S.; Ziskin, D.; Durbin, P. B.; Protack, S.; Rinsland, P. L.; Slayback, D. A.; Policelli, F. S.; Olsina, O.; Fu, G.; Ederer, G. A.; Ding, F.; Braun, J.; Gumley, L.; Prins, E. M.; Davidson, C. C.; Wong, M. M.

2017-12-01

NASA's Land, Atmosphere Near real-time Capability for EOS (LANCE) is a virtual system that provides near real-time EOS data and imagery to meet the needs of scientists and application users interested in monitoring a wide variety of natural and man-made phenomena in near real-time. Over the last year: near real-time products and imagery from MOPITT, MISR, OMPS and VIIRS (Land and Atmosphere) have been added; the Fire Information for Resource Management System (FIRMS) has been updated and LANCE has begun the process of integrating the Global NRT flood product. In addition, following the AMSU-A2 instrument anomaly in September 2016, AIRS-only products have replaced the NRT level 2 AIRS+AMSU products. This presentation provides a brief overview of LANCE, describes the new products that are recently available and contains a preview of what to expect in LANCE over the coming year. For more information visit: https://earthdata.nasa.gov/lance

Validation of catchment models for predicting land-use and climate change impacts. 1. Method

NASA Astrophysics Data System (ADS)

Ewen, J.; Parkin, G.

1996-02-01

Computer simulation models are increasingly being proposed as tools capable of giving water resource managers accurate predictions of the impact of changes in land-use and climate. Previous validation testing of catchment models is reviewed, and it is concluded that the methods used do not clearly test a model's fitness for such a purpose. A new generally applicable method is proposed. This involves the direct testing of fitness for purpose, uses established scientific techniques, and may be implemented within a quality assured programme of work. The new method is applied in Part 2 of this study (Parkin et al., J. Hydrol., 175:595-613, 1996).

Development of a NASA 2018 Mars Landed Mission Concept

NASA Technical Reports Server (NTRS)

Wilson, M. G.; Salvo, C. G.; Abilleira, F.; Sengstacken, A. J.; Allwood, A. G.; Backes, P. G.; Lindemann, R. A.; Jordan, J. F.

2010-01-01

Fundamental to NASA's Mars Exploration Program (MEP) is an ongoing development of an integrated and coordinated set of possible future candidate missions that meet fundamental science and programmatic objectives of NASA and the Mars scientific community. In the current planning horizon of the NASA MEP, a landed mobile surface exploration mission launching in the 2018 Mars launch opportunity exists as a candidate project to meet MEP in situ science and exploration objectives. This paper describes the proposed mission science objectives and the mission implementation concept developed for the 2018 opportunity. As currently envisioned, this mission concept seeks to explore a yet-to-be-selected site with high preservation potential for physical and chemical biosignatures, evaluate paleoenvironmental conditions, characterize the potential for preservation of biosignatures, and access multiple sequences of geological units in a search for evidence of past life and/or prebiotic chemistry at a site on Mars.

Drought propagation and its relation with catchment biophysical characteristics

NASA Astrophysics Data System (ADS)

Alvarez-Garreton, C. D.; Lara, A.; Garreaud, R. D.

2016-12-01

Droughts propagate in the hydrological cycle from meteorological to soil moisture to hydrological droughts. To understand the drivers of this process is of paramount importance since the economic and societal impacts in water resources are directly related with hydrological droughts (and not with meteorological droughts, which have been most studied). This research analyses drought characteristics over a large region and identify its main exogenous (climate forcing) and endogenous (biophysical characteristics such as land cover type and topography) explanatory factors. The study region is Chile, which covers seven major climatic subtypes according to Köppen system, it has unique geographic characteristics, very sharp topography and a wide range of landscapes and vegetation conditions. Meteorological and hydrological droughts (deficit in precipitation and streamflow, respectively) are characterized by their durations and standardized deficit volumes using a variable threshold method, over 300 representative catchments (located between 27°S and 50°S). To quantify the propagation from meteorological to hydrological drought, we propose a novel drought attenuation index (DAI), calculated as the ratio between the meteorological drought severity slope and the hydrological drought severity slope. DAI varies from zero (catchment that attenuates completely a meteorological drought) to one (the meteorological drought is fully propagated through the hydrological cycle). This novel index provides key (and comparable) information about drought propagation over a wide range of different catchments, which has been highlighted as a major research gap. Similar drought indicators across the wide range of catchments are then linked with catchment biophysical characteristics. A thorough compilation of land cover information (including the percentage of native forests, grass land, urban and industrial areas, glaciers, water bodies and no vegetated areas), catchment physical

The application of GEOtop for catchment scale hydrology in Ireland

NASA Astrophysics Data System (ADS)

Lewis, C.; Xu, X.; Albertson, J.; Kiely, G.

2009-04-01

GEOtop represents the new generation of distributed hydrological model driven by geospatial data (e.g. topography, soils, vegetation, land cover). It estimates rainfall-runoff, evapotranspiration and provides spatially distributed outputs as well as routing water and sediment flows through stream and river networks. The original version of GEOtop designed in Italy, includes a rigorous treatment of the core hydrological processes (e.g. unsaturated and saturated flow and transport, surface energy balances, and streamflow generation/routing). Recently GEOtop was extended to include treatment of shallow landslides. The GEOtop model is built on an open-source programming framework, which makes it well suited for adaptation and extension. GEOtop has been run very successfully in a number of alpine catchments (such as Brenta) but has not been used on Irish catchments before. The cell size used for the spatially distributed inputs varies from catchment to catchment. In smaller catchments (less than 2000ha) 50 by 50m cells have been used and 200 by 200 for larger catchments. Smaller cell sizes have been found to significantly increase the computational time so a larger cell size is used providing it does not significantly affect the performance of the model. Digital elevation model, drainage direction, landuse and soil type maps are the minimum spatial requirements with precipitation, radiation, temperature, atmospheric pressure and wind speed been the minimum meteorological requirements for a successful run. The soil type maps must also contain information regarding texture and hydraulic conductivity. The first trial of GEOtop in Ireland was on a small 1524 ha catchment in the south of Ireland. The catchment ranges from 50 to just over 200m, the land use is predominately agricultural grassland and it receives on average 1400mm of rain per year. Within this catchment there is a meteorological tower which provides the meteorological inputs, soil moisture is also recorded at

Using High-Resolution Data to Assess Land Use Impact on Nitrate Dynamics in East African Tropical Montane Catchments

NASA Astrophysics Data System (ADS)

Jacobs, Suzanne R.; Weeser, Björn; Guzha, Alphonce C.; Rufino, Mariana C.; Butterbach-Bahl, Klaus; Windhorst, David; Breuer, Lutz

2018-03-01

Land use change alters nitrate (NO3-N) dynamics in stream water by changing nitrogen cycling, nutrient inputs, uptake and hydrological flow paths. There is little empirical evidence of these processes for East Africa. We collected a unique 2 year high-resolution data set to assess the effects of land use (i.e., natural forest, smallholder agriculture and commercial tea plantations) on NO3-N dynamics in three subcatchments within a headwater catchment in the Mau Forest Complex, Kenya's largest tropical montane forest. The natural forest subcatchment had the lowest NO3-N concentrations (0.44 ± 0.043 mg N L-1) with no seasonal variation. NO3-N concentrations in the smallholder agriculture (1.09 ± 0.11 mg N L-1) and tea plantation (2.13 ± 0.19 mg N L-1) subcatchments closely followed discharge patterns, indicating mobilization of NO3-N during the rainy seasons. Hysteresis patterns of rainfall events indicate a shift from subsurface flow in the natural forest to surface runoff in agricultural subcatchments. Distinct peaks in NO3-N concentrations were observed during rainfall events after a longer dry period in the forest and tea subcatchments. The high-resolution data set enabled us to identify differences in NO3-N transport of catchments under different land use, such as enhanced NO3-N inputs to the stream during the rainy season and higher annual export in agricultural subcatchments (4.9 ± 0.3 to 12.0 ± 0.8 kg N ha-1 yr-1) than in natural forest (2.6 ± 0.2 kg N ha-1 yr-1). This emphasizes the usefulness of our monitoring approach to improve the understanding of land use effects on riverine N exports in tropical landscapes, but also the need to apply such methods in other regions.

Influence of Terrain and Land Cover on the Isotopic Composition of Seasonal Snowpack in Rocky Mountain Headwater Catchments Affected by Bark Beetle Induced Tree Mortality

NASA Astrophysics Data System (ADS)

Kipnis, E. L.; Murphy, M.; Klatt, A. L.; Miller, S. N.; Williams, D. G.

2015-12-01

Session H103: The Hydrology-Vegetation-Climate Nexus: Identifying Process Interactions and Environmental Shifts in Mountain Catchments Influence of Terrain and Land Cover on the Isotopic Composition of Seasonal Snowpack in Rocky Mountain Headwater Catchments Affected by Bark Beetle Induced Tree Mortality Evan L Kipnis, Melanie A Murphey, Alan Klatt, Scott N Miller, David G Williams Snowpack accumulation and ablation remain difficult to estimate in forested headwater catchments. How physical terrain and forest cover separately and interactively influence spatial patterns of snow accumulation and ablation largely shapes the hydrologic response to land cover disturbances. Analysis of water isotopes in snowpack provides a powerful tool for examining integrated effects of water vapor exchange, selective redistribution, and melt. Snow water equivalence (SWE), δ2H, δ18O and deuterium excess (D-excess) of snowpack were examined throughout winter 2013-2014 across two headwater catchments impacted by bark beetle induced tree mortality. A USGS 10m DEM and a derived land cover product from 1m NAIP imagery were used to examine the effects of terrain features (e.g., elevation, slope, aspect) and canopy disturbance (e.g., live, bark-beetle killed) as predictors of D-excess, an expression of kinetic isotope effects, in snowpack. A weighting of Akaike's Information Criterion (AIC) values from multiple spatially lagged regression models describing D-excess variation for peak snowpack revealed strong effects of elevation and canopy mortality, and weaker, but significant effects of aspect and slope. Snowpack D-excess was lower in beetle-killed canopy patches compared to live green canopy patches, and at lower compared to high elevation locations, suggesting that integrated isotopic effects of vapor exchange, vertical advection of melted snow, and selective accumulation and redistribution varied systematically across the two catchments. The observed patterns illustrate the potential

Soil erosion and sediment delivery issues in a large hydro-electric power reservoir catchment, Ethiopia

NASA Astrophysics Data System (ADS)

Nebiyu, Amsalu; Dume, Bayu; Bode, Samuel; Ram, Hari; Boeckx, Pascal

2017-04-01

Land degradation and associated processes such as gullying, flooding and sedimentation, are among the developmental challenges in many countries and HEP reservoirs in the Gilgel Gibe catchment, Ethiopia, are under threat from siltation. Soil erosion is one of the biggest global environmental problems resulting in both on-site and offsite effects which have economic implications and an essential actor in assessing ecosystem health and function. Sediment supply in a catchment is heterogeneous in time and space depending on climate, land use and a number of landscape characteristics such as slope, topography, soil type, vegetation and drainage conditions. In the Ethiopian highlands, sediment delivery depends on discharge, the onset of rainfall, land use and land cover, which varies between rainfall seasons. There is also a variation among catchments in suspended sediment concentration due to the variation in the catchments characteristics in Ethiopia. Rainfall-runoff relationship, sediment production and delivery to rivers or dams is variable and poorly understood; due to heterogeneous lithology; various climatic conditions across small spatial scales; land use and land management practices in Ethiopia. Spatial variation in sediment yield in Africa varies to differences in seismic activity, topography, vegetation cover and annual runoff depth. In the Gilgel-Gibe catchment, the annual sediment load of the Gilgel-Gibe River has been estimated to be about 4.5×107 tons taking the contribution of sheet erosion alone. Also, the suspended sediment yield of the tributaries in Gilgel-Gibe catchment has been estimated to be in the range of 0.4-132.1 tons per hectare per year. The soil loss due to landslide alone in the past 20 years in the catchment was about 11 t/ha/yr. Heavy rainfall, bank erosion and river incisions have been indicated as the main triggering factors for landslides and the associated sediment delivery in the Gilgel-Gibe catchment. Approaches for catchment

Rapid prototyping of soil moisture estimates using the NASA Land Information System

NASA Astrophysics Data System (ADS)

Anantharaj, V.; Mostovoy, G.; Li, B.; Peters-Lidard, C.; Houser, P.; Moorhead, R.; Kumar, S.

2007-12-01

The Land Information System (LIS), developed at the NASA Goddard Space Flight Center, is a functional Land Data Assimilation System (LDAS) that incorporates a suite of land models in an interoperable computational framework. LIS has been integrated into a computational Rapid Prototyping Capabilities (RPC) infrastructure. LIS consists of a core, a number of community land models, data servers, and visualization systems - integrated in a high-performance computing environment. The land surface models (LSM) in LIS incorporate surface and atmospheric parameters of temperature, snow/water, vegetation, albedo, soil conditions, topography, and radiation. Many of these parameters are available from in-situ observations, numerical model analysis, and from NASA, NOAA, and other remote sensing satellite platforms at various spatial and temporal resolutions. The computational resources, available to LIS via the RPC infrastructure, support e- Science experiments involving the global modeling of land-atmosphere studies at 1km spatial resolutions as well as regional studies at finer resolutions. The Noah Land Surface Model, available with-in the LIS is being used to rapidly prototype soil moisture estimates in order to evaluate the viability of other science applications for decision making purposes. For example, LIS has been used to further extend the utility of the USDA Soil Climate Analysis Network of in-situ soil moisture observations. In addition, LIS also supports data assimilation capabilities that are used to assimilate remotely sensed soil moisture retrievals from the AMSR-E instrument onboard the Aqua satellite. The rapid prototyping of soil moisture estimates using LIS and their applications will be illustrated during the presentation.

Application of a Three-Dimensional Water Quality Model as a Decision Support Tool for the Management of Land-Use Changes in the Catchment of an Oligotrophic Lake

NASA Astrophysics Data System (ADS)

Trolle, Dennis; Spigel, Bob; Hamilton, David P.; Norton, Ned; Sutherland, Donna; Plew, David; Allan, Mathew G.

2014-09-01

While expansion of agricultural land area and intensification of agricultural practices through irrigation and fertilizer use can bring many benefits to communities, intensifying land use also causes more contaminants, such as nutrients and pesticides, to enter rivers, lakes, and groundwater. For lakes such as Benmore in the Waitaki catchment, South Island, New Zealand, an area which is currently undergoing agricultural intensification, this could potentially lead to marked degradation of water clarity as well as effects on ecological, recreational, commercial, and tourism values. We undertook a modeling study to demonstrate science-based options for consideration of agricultural intensification in the catchment of Lake Benmore. Based on model simulations of a range of potential future nutrient loadings, it is clear that different areas within Lake Benmore may respond differently to increased nutrient loadings. A western arm (Ahuriri) could be most severely affected by land-use changes and associated increases in nutrient loadings. Lake-wide annual averages of an eutrophication indicator, the trophic level index (TLI) were derived from simulated chlorophyll a, total nitrogen, and total phosphorus concentrations. Results suggest that the lake will shift from oligotrophic (TLI = 2-3) to eutrophic (TLI = 4-5) as external loadings are increased eightfold over current baseline loads, corresponding to the potential land-use intensification in the catchment. This study provides a basis for use of model results in a decision-making process by outlining the environmental consequences of a series of land-use management options, and quantifying nutrient load limits needed to achieve defined trophic state objectives.

Effects of land use and seasonality on stream water quality in a small tropical catchment: The headwater of Córrego Água Limpa, São Paulo (Brazil).

PubMed

Rodrigues, Valdemir; Estrany, Joan; Ranzini, Mauricio; de Cicco, Valdir; Martín-Benito, José Mª Tarjuelo; Hedo, Javier; Lucas-Borja, Manuel E

2018-05-01

Stream water quality is controlled by the interaction of natural and anthropogenic factors over a range of temporal and spatial scales. Among these anthropogenic factors, land cover changes at catchment scale can affect stream water quality. This work aims to evaluate the influence of land use and seasonality on stream water quality in a representative tropical headwater catchment named as Córrego Água Limpa (Sao Paulo, Brasil), which is highly influenced by intensive agricultural activities and urban areas. Two systematic sampling approach campaigns were implemented with six sampling points along the stream of the headwater catchment to evaluate water quality during the rainy and dry seasons. Three replicates were collected at each sampling point in 2011. Electrical conductivity, nitrates, nitrites, sodium superoxide, Chemical Oxygen Demand (DQO), colour, turbidity, suspended solids, soluble solids and total solids were measured. Water quality parameters differed among sampling points, being lower at the headwater sampling point (0m above sea level), and then progressively higher until the last downstream sampling point (2500m above sea level). For the dry season, the mean discharge was 39.5ls -1 (from April to September) whereas 113.0ls -1 were averaged during the rainy season (from October to March). In addition, significant temporal and spatial differences were observed (P<0.05) for the fourteen parameters during the rainy and dry period. The study enhance significant relationships among land use and water quality and its temporal effect, showing seasonal differences between the land use and water quality connection, highlighting the importance of multiple spatial and temporal scales for understanding the impacts of human activities on catchment ecosystem services. Copyright © 2017 Elsevier B.V. All rights reserved.

The influence of land use change on landslide susceptibility zonation: the Briga catchment test site (Messina, Italy).

PubMed

Reichenbach, P; Busca, C; Mondini, A C; Rossi, M

2014-12-01

The spatial distribution of landslides is influenced by different climatic conditions and environmental settings including topography, morphology, hydrology, lithology, and land use. In this work, we have attempted to evaluate the influence of land use change on landslide susceptibility (LS) for a small study area located in the southern part of the Briga catchment, along the Ionian coast of Sicily (Italy). On October 1, 2009, the area was hit by an intense rainfall event that triggered abundant slope failures and resulted in widespread erosion. After the storm, an inventory map showing the distribution of pre-event and event landslides was prepared for the area. Moreover, two different land use maps were developed: the first was obtained through a semi-automatic classification of digitized aerial photographs acquired in 1954, the second through the combination of supervised classifications of two recent QuickBird images. Exploiting the two land use maps and different land use scenarios, LS zonations were prepared through multivariate statistical analyses. Differences in the susceptibility models were analyzed and quantified to evaluate the effects of land use change on the susceptibility zonation. Susceptibility maps show an increase in the areal percentage and number of slope units classified as unstable related to the increase in bare soils to the detriment of forested areas.

Supersonic Retropropulsion Technology Development in NASA's Entry, Descent, and Landing Project

NASA Technical Reports Server (NTRS)

Edquist, Karl T.; Berry, Scott A.; Rhode, Matthew N.; Kelb, Bil; Korzun, Ashley; Dyakonov, Artem A.; Zarchi, Kerry A.; Schauerhamer, Daniel G.; Post, Ethan A.

2012-01-01

NASA's Entry, Descent, and Landing (EDL) space technology roadmap calls for new technologies to achieve human exploration of Mars in the coming decades [1]. One of those technologies, termed Supersonic Retropropulsion (SRP), involves initiation of propulsive deceleration at supersonic Mach numbers. The potential benefits afforded by SRP to improve payload mass and landing precision make the technology attractive for future EDL missions. NASA's EDL project spent two years advancing the technological maturity of SRP for Mars exploration [2-15]. This paper summarizes the technical accomplishments from the project and highlights challenges and recommendations for future SRP technology development programs. These challenges include: developing sufficiently large SRP engines for use on human-scale entry systems; testing and computationally modelling complex and unsteady SRP fluid dynamics; understanding the effects of SRP on entry vehicle stability and controllability; and demonstrating sub-scale SRP entry systems in Earth's atmosphere.

Spatiotemporal variability of hydrologic soil properties and the implications for overland flow and land management in a peri-urban Mediterranean catchment

NASA Astrophysics Data System (ADS)

Ferreira, C. S. S.; Walsh, R. P. D.; Steenhuis, T. S.; Shakesby, R. A.; Nunes, J. P. N.; Coelho, C. O. A.; Ferreira, A. J. D.

2015-06-01

Planning of semi-urban developments is often hindered by a lack of knowledge on how changes in land-use affect catchment hydrological response. The temporal and spatial patterns of overland flow source areas and their connectivity in the landscape, particularly in a seasonal climate, remain comparatively poorly understood. This study investigates seasonal variations in factors influencing runoff response to rainfall in a peri-urban catchment in Portugal characterized by a mosaic of landscape units and a humid Mediterranean climate. Variations in surface soil moisture, hydrophobicity and infiltration capacity were measured in six different landscape units (defined by land-use on either sandstone or limestone) in nine monitoring campaigns at key times over a one-year period. Spatiotemporal patterns in overland flow mechanisms were found. Infiltration-excess overland flow was generated in rainfalls during the dry summer season in woodland on both sandstone and limestone and on agricultural soils on limestone due probably in large part to soil hydrophobicity. In wet periods, saturation overland flow occurred on urban and agricultural soils located in valley bottoms and on shallow soils upslope. Topography, water table rise and soil depth determined the location and extent of saturated areas. Overland flow generated in upslope source areas potentially can infiltrate in other landscape units downslope where infiltration capacity exceeds rainfall intensity. Hydrophilic urban and agricultural-sandstone soils were characterized by increased infiltration capacity during dry periods, while forest soils provided potential sinks for overland flow when hydrophilic in the winter wet season. Identifying the spatial and temporal variability of overland flow sources and sinks is an important step in understanding and modeling flow connectivity and catchment hydrologic response. Such information is important for land managers in order to improve urban planning to minimize flood risk.

River-groundwater connectivity and nutrient dynamics in a mesoscale catchment

NASA Astrophysics Data System (ADS)

Fleckenstein, Jan H.; Musolff, Andreas; Gilfedder, Benjamin; Frei, Sven; Wankmüller, Fabian; Trauth, Nico

2017-04-01

Diffuse solute exports from catchments are governed by many interrelated factors such as land use, climate, geological-/ hydrogeological setup and morphology. Those factors create spatial variations in solute concentrations and turnover rates in the subsurface as well as in the stream network. River-groundwater connectivity is a crucial control in this context: On the one hand groundwater is a main pathway for nitrate inputs to the stream. On the other hand, groundwater connectivity with the stream affects the magnitude of hyporheic exchange of stream water with the stream bed. We present results of a longitudinal sampling campaign along the Selke river, a 67 km long third-order stream in the Harz mountains in central Germany. Water quality at the catchment outlet is strongly impacted by agriculture with high concentrations of nitrate and a chemostatic nitrate export regime. However, the specific nitrate pathways to the stream are not fully understood as there is arable land distributed throughout the catchment. While the sparsely distributed arable land in the mountainous upper catchment receives much higher amounts of precipitation, the downstream alluvial plains are drier, but more intensively used. The three-day campaign was conducted in June 2016 under constant low flow conditions. Stream water samples were taken every 2 km along the main stem of the river and at its major tributaries. Samples were analyzed for field parameters, major cations and anions, N-O isotopes, nutrients and Radon-222 (Rn) concentrations. Additionally, at each sampling location, river discharge was manually measured using current meters. Groundwater influxes to each sampled river section were quantified from the Rn measurements using the code FINIFLUX, (Frei and Gilfedder 2015). Rn and ion concentrations showed an increase from the spring to the mouth, indicating a growing impact of groundwater flux to the river. However, increases in groundwater gains were not gradual. The strongest

Quantifying nonpoint source emissions and their water quality responses in a complex catchment: A case study of a typical urban-rural mixed catchment

NASA Astrophysics Data System (ADS)

Chen, Lei; Dai, Ying; Zhi, Xiaosha; Xie, Hui; Shen, Zhenyao

2018-04-01

As two key threats to receiving water bodies, the generation mechanisms and processes of urban and agricultural nonpoint sources (NPSs) show clear differences, which lead to distinct characteristics of water quality responses with mixed land-uses catchments compared to single land-use ones. However, few studies have provided such insights in these characteristic or quantified different water environment responses to NPS pollution. In this study, an integrated modelling approach was developed for those complex catchments by combining three commonly used models: SWMM (Storm Water Management Model), SWAT (Soil and Water Assessment Tool) and MIKE 11. A case study was performed in a typical urban-rural catchment of Chao Lake, China. The simulated results indicated that urban NPS pollution responded sensitively to rainfall events and was greatly affected by the antecedent dry days. Compare to urban NPS, agricultural NPS pollution was characterized with the time-lag to rainfall depended on soil moisture and the post-rain-season emissions carried by lateral flows, and were also affected by the local farm-practice schedule. With comprehensive impacts from urban-rural land-uses, the time-interleaved urban and agricultural NPS pollution emissions and more abundant pollution accumulation both led to a decrease in the responsive time and an increase in the frequency of peak pollution concentration values even during the dry season. These obtained characteristics can provide guidance for drafting watershed management plans in similar mixed land use catchments.

Seasonal scale water deficit forecasting in Africa and the Middle East using NASA's Land Information System (LIS)

NASA Astrophysics Data System (ADS)

Peters-Lidard, C. D.; Arsenault, K. R.; Shukla, S.; Getirana, A.; McNally, A.; Koster, R. D.; Zaitchik, B. F.; Badr, H. S.; Roningen, J. M.; Kumar, S.; Funk, C. C.

2017-12-01

A seamless and effective water deficit monitoring and early warning system is critical for assessing food security in Africa and the Middle East. In this presentation, we report on the ongoing development and validation of a seasonal scale water deficit forecasting system based on NASA's Land Information System (LIS) and seasonal climate forecasts. First, our presentation will focus on the implementation and validation of drought and water availability monitoring products in the region. Next, it will focus on evaluating drought and water availability forecasts. Finally, details will be provided of our ongoing collaboration with end-user partners in the region (e.g., USAID's Famine Early Warning Systems Network, FEWS NET), on formulating meaningful early warning indicators, effective communication and seamless dissemination of the products through NASA's web-services. The water deficit forecasting system thus far incorporates NASA GMAO's Catchment and the Noah Multi-Physics (MP) LSMs. In addition, the LSMs' surface and subsurface runoff are routed through the Hydrological Modeling and Analysis Platform (HyMAP) to simulate surface water dynamics. To establish a climatology from 1981-2015, the two LSMs are driven by NASA/GMAO's Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2), and the USGS and UCSB Climate Hazards Group InfraRed Precipitation with Station (CHIRPS) daily rainfall dataset. Comparison of the models' energy and hydrological budgets with independent observations suggests that major droughts are well-reflected in the climatology. The system uses seasonal climate forecasts from NASA's GEOS-5 (the Goddard Earth Observing System Model-5) and NCEP's Climate Forecast System-2, and it produces forecasts of soil moisture, ET and streamflow out to 6 months in the future. Forecasts of those variables are formulated in terms of indicators to provide forecasts of drought and water availability in the region. Current work suggests

STS-35 crew and NASA management inspect OV-102 after landing at EAFB, Calif

NASA Technical Reports Server (NTRS)

1990-01-01

STS-35 NASA JSC Flight Crew Operations Directorate (FCOD) Director Donald R. Puddy (center) joins the STS-35 crewmembers in a post landing walk-around inspection of Columbia, Orbiter Vehicle (OV) 102, at Edwards Air Force Base (EAFB), California. Crewmembers, wearing launch and entry suits (LESs), include (left to right) Commander Vance D. Brand, Mission Specialist (MS) John M. Lounge, Payload Specialist Ronald A. Parise, Pilot Guy S. Gardner, and MS Jeffrey A. Hoffman. NASA Associate Administrator for Space Flight Dr. William B. Lenoir is at far left in the background. OV-102 landed on concrete runway 22 at EAFB at 9:54:09 pm (Pacific Standard Time (PST)). OV-102's nose cone and nose landing gear (NLG) door are visible at the left corner of the frame.

Land-use effects on fluxes of suspended sediment, nitrogen and phosphorus from a river catchment of the Great Barrier Reef, Australia

NASA Astrophysics Data System (ADS)

Hunter, Heather M.; Walton, Richard S.

2008-07-01

SummaryA 6-year study was conducted in the Johnstone River system in the wet tropics of north-eastern Australia, to address concerns that the Great Barrier Reef is at risk from elevated levels of suspended sediment (SS) and nutrients discharged from its river catchments. Aims were to quantify: (i) fluxes of SS, phosphorus (P) and nitrogen (N) exported annually from the catchment and (ii) the influence of rural land uses on these fluxes. Around 55% of the 1602 km2 catchment was native rainforest, with the reminder developed mainly for livestock and crop production. Water quality and stream flow were monitored at 16 sites, with the emphasis on sampling major runoff events. Monitoring data were used to calibrate a water quality model for the catchment (HSPF), which was run with 39 years of historical precipitation and evaporation data. Modelled specific fluxes from the catchment of 1.2 ± 1.1 t SS ha-1 y-1, 2.2 ± 1.8 kg P ha-1 y-1 and 11.4 ± 7.3 kg N ha-1y-1 were highly variable between and within years. Fluxes of SS and P were strongly dominated by major events, with 91% of SS and 84% of P exported during the highest 10% of daily flows. On average, sediment P comprised 81% of the total P flux. The N flux was less strongly dominated by major events and sediment N comprised 46% of total N exports. Specific fluxes of SS, N and P from areas receiving precipitation of 3545 mm y-1 were around 3-4 times those from areas receiving 1673 mm y-1. For a given mean annual precipitation, specific fluxes of SS and P from beef pastures, dairy pastures and unsewered residential areas were similar to those from rainforest, while fluxes from areas of sugar cane and bananas were 3-4 times higher. Specific fluxes of N from areas with an annual precipitation of 3545 mm ranged from 8.9 ± 6.5 kg N ha-1 y-1 (rainforest) to 72 ± 50 kg N ha-1 y-1 (unsewered residential). Aggregated across the entire catchment, disproportionately large fluxes of SS, total P and total N were derived from

NASA's MODIS/VIIRS Land Surface Temperature and Emissivity Products: Asssessment of Accuracy, Continuity and Science Uses

NASA Astrophysics Data System (ADS)

Hulley, G. C.; Malakar, N.; Islam, T.

2017-12-01

Land Surface Temperature and Emissivity (LST&E) are an important Earth System Data Record (ESDR) and Environmental Climate Variable (ECV) defined by NASA and GCOS respectively. LST&E data are key variables used in land cover/land use change studies, in surface energy balance and atmospheric water vapor retrieval models and retrievals, and in climate research. LST&E products are currently produced on a routine basis using data from the MODIS instruments on the NASA EOS platforms and by the VIIRS instrument on the Suomi-NPP platform that serves as a bridge between NASA EOS and the next-generation JPSS platforms. Two new NASA LST&E products for MODIS (MxD21) and VIIRS (VNP21) are being produced during 2017 using a new approach that addresses discrepancies in accuracy and consistency between the current suite of split-window based LST products. The new approach uses a Temperature Emissivity Separation (TES) algorithm, originally developed for the ASTER instrument, to physically retrieve both LST and spectral emissivity consistently for both sensors with high accuracy and well defined uncertainties. This study provides a rigorous assessment of accuracy of the MxD21/VNP21 products using temperature- and radiance-based validation strategies and demonstrates continuity between the products using collocated matchups over CONUS. We will further demonstrate potential science use of the new products with studies related to heat waves, monitoring snow melt dynamics, and land cover/land use change.

Assessing catchment connectivity using hysteretic loops

NASA Astrophysics Data System (ADS)

Davis, Jason; Masselink, Rens; Goni, Mikel; Gimenez, Rafael; Casali, Javier; Seeger, Manuel; Keesstra, Saskia

2017-04-01

texture topsoil), climate (humid sub Mediterranean) and land use (80-90% cultivated with winter grain crops). Ozkotz principal (ca.1,700 ha) is covered with forest and pasture (cattle-breeding); while Oskotz woodland (ca. 500 ha), a sub-watershed of the Oskotz principal, is almost completely covered with forest. The predominant climate in the Oskotz catchments sub-Atlantic. Furthermore, antecedent conditions and event characteristics were analysed. The loops were compared quantitatively and qualitatively between catchments for similar events and within the catchments for events with different characteristics. In this study, several measures to objectively classify hysteresis loops in an automated way were developed. These were consecutively used to classify several hundreds of loops from several agricultural catchments in Northern Spain. These loop characteristics were compared to event specific characteristics such as antecedent precipitation, time of year, and precipitation intensity, duration and total. The combination of hysteresis loops and variables influencing connectivity can then tell something about the sources of sediments for different events and catchments. References Baartman, J.E.M., Masselink, R.H., Keesstra, S.D., Temme, A.J.A.M., 2013. Linking landscape morphological complexity and sediment connectivity. Earth Surface Processes and Landforms 38: 1457-1471. Masselink RJH, Heckmann T, Temme AJAM, Anders NS, Gooren HPA, Keesstra SD. 2016. A network theory approach for a better understanding of overland flow connectivity. Hydrological Processes. DOI: 10.1002/hyp.10993 Masselink, R.J.H., Keesstra, S.D., Temme, A.J.A.M., Seeger, M., Giménez, R., Casalí, J., 2016. Modelling Discharge and Sediment Yield at Catchment Scale Using Connectivity Components. Land Degradation and Development 27: 933-945, DOI: 10.1002/ldr.2512 Mekonnen, M., Keesstra, S.D., Baartman, J.E.M., Stroosnijder, L., Maroulis, J., Reducing sediment connectivity through man-made and natural

Climate change adaptation via targeted ecosystem service provision: a sustainable land management strategy for the Segura catchment (SE Spain)

NASA Astrophysics Data System (ADS)

Zagaria, Cecilia; de Vente, Joris; Perez-Cutillas, Pedro

2014-05-01

Topical research investigating climate, land-use and management scenarios in the Segura catchment (SE Spain), depicts a landscape at high-risk of, quite literally, deserting agriculture. Land degradation in the semi-arid region of SE Spain is characterized by water shortage, high erosion rates and salinization, increasingly exacerbated by climatic changes, scarce vegetation cover and detrimental farming practices. Future climate scenarios predict increases in aridity, variability and intensity of rainfall events, leading to increasing pressure on scarce soil and water resources. This study conceptualized the impending crisis of agro-ecological systems of the Segura basin (18800 km2) as a crisis of ecosystem service deterioration. In light of existing land degradation drivers and future climate scenarios, the potential of Sustainable Land Management (SLM) strategies was evaluated to target three priority ecosystem services (water provision, sediment retention and carbon sequestration) as a means to achieve climate change adaptation and mitigation. A preceding thorough process of stakeholder engagement (as part of the EU funded DESIRE project) indicated five SLM technologies for potential implementation, all with a focus upon reducing soil erosion, increasing soil water holding capacity and soil organic matter content. These technologies have been tested for over four years in local experimental field plots, and have provided results on the local effects upon individual environmental parameters. Despite the growing emphasis witnessed in literature upon the context-specificity which characterizes adaptation solutions, the frequent analysis at the field scale is limited in both scope and utility. There is a need to investigate the effects of adaptive SLM solutions at wider, regional scales. Thus, this study modeled the cumulative effect of each of the five selected SLM technologies with InVEST, a spatial analyst tool designed for ecosystem service quantification and

Which catchment characteristics control the temporal dependence structure of daily river flows?

NASA Astrophysics Data System (ADS)

Chiverton, Andrew; Hannaford, Jamie; Holman, Ian; Corstanje, Ron; Prudhomme, Christel; Bloomfield, John; Hess, Tim

2014-05-01

A hydrological classification system would provide information about the dominant processes in the catchment enabling information to be transferred between catchments. Currently there is no widely-agreed upon system for classifying river catchments. This paper developed a novel approach to assess the influence that catchment characteristics have on the precipitation-to-flow relationship, using a catchment classification based on the average temporal dependence structure in daily river flow data over the period 1980 to 2010. Temporal dependence in river flow data is driven by the flow pathways, connectivity and storage within the catchment. Temporal dependence was analysed by creating temporally averaged semi-variograms for a set of 116 near-natural catchments (in order to prevent direct anthropogenic disturbances influencing the results) distributed throughout the UK. Cluster analysis, using the variogram, classified the catchments into four well defined clusters driven by the interaction of catchment characteristics, predominantly characteristics which influence the precipitation-to-flow relationship. Geology, depth to gleyed layer in soils, slope of the catchment and the percentage of arable land were significantly different between the clusters. These characteristics drive the temporal dependence structure by influencing the rate at which water moves through the catchment and / or the storage in the catchment. Arable land is correlated with several other variables, hence is a proxy indicating the residence time of the water in the catchment. Finally, quadratic discriminant analysis was used to show that a model with five catchment characteristics is able to predict the temporal dependence structure for un-gauged catchments. This work demonstrates that a variogram-based approach is a powerful and flexible methodology for grouping catchments based on the precipitation-to-flow relationship which could be applied to any set of catchments with a relatively complete

The Use of Asymptotic Functions for Determining Empirical Values of CN Parameter in Selected Catchments of Variable Land Cover

NASA Astrophysics Data System (ADS)

Wałęga, Andrzej; Młyński, Dariusz; Wachulec, Katarzyna

2017-12-01

The aim of the study was to assess the applicability of asymptotic functions for determining the value of CN parameter as a function of precipitation depth in mountain and upland catchments. The analyses were carried out in two catchments: the Rudawa, left tributary of the Vistula, and the Kamienica, right tributary of the Dunajec. The input material included data on precipitation and flows for a multi-year period 1980-2012, obtained from IMGW PIB in Warsaw. Two models were used to determine empirical values of CNobs parameter as a function of precipitation depth: standard Hawkins model and 2-CN model allowing for a heterogeneous nature of a catchment area. The study analyses confirmed that asymptotic functions properly described P-CNobs relationship for the entire range of precipitation variability. In the case of high rainfalls, CNobs remained above or below the commonly accepted average antecedent moisture conditions AMCII. The study calculations indicated that the runoff amount calculated according to the original SCS-CN method might be underestimated, and this could adversely affect the values of design flows required for the design of hydraulic engineering projects. In catchments with heterogeneous land cover, the results of CNobs were more accurate when 2-CN model was used instead of the standard Hawkins model. 2-CN model is more precise in accounting for differences in runoff formation depending on retention capacity of the substrate. It was also demonstrated that the commonly accepted initial abstraction coefficient λ = 0.20 yielded too big initial loss of precipitation in the analyzed catchments and, therefore, the computed direct runoff was underestimated. The best results were obtained for λ = 0.05.

High Performance Hydrometeorological Modeling, Land Data Assimilation and Parameter Estimation with the Land Information System at NASA/GSFC

NASA Astrophysics Data System (ADS)

Peters-Lidard, C. D.; Kumar, S. V.; Santanello, J. A.; Tian, Y.; Rodell, M.; Mocko, D.; Reichle, R.

2008-12-01

The Land Information System (LIS; http://lis.gsfc.nasa.gov; Kumar et al., 2006; Peters-Lidard et al., 2007) is a flexible land surface modeling framework that has been developed with the goal of integrating satellite- and ground-based observational data products and advanced land surface modeling techniques to produce optimal fields of land surface states and fluxes. The LIS software was the co-winner of NASA's 2005 Software of the Year award. LIS facilitates the integration of observations from Earth-observing systems and predictions and forecasts from Earth System and Earth science models into the decision-making processes of partnering agency and national organizations. Due to its flexible software design, LIS can serve both as a Problem Solving Environment (PSE) for hydrologic research to enable accurate global water and energy cycle predictions, and as a Decision Support System (DSS) to generate useful information for application areas including disaster management, water resources management, agricultural management, numerical weather prediction, air quality and military mobility assessment. LIS has evolved from two earlier efforts - North American Land Data Assimilation System (NLDAS; Mitchell et al. 2004) and Global Land Data Assimilation System (GLDAS; Rodell et al. 2004) that focused primarily on improving numerical weather prediction skills by improving the characterization of the land surface conditions. Both of these systems, now use specific configurations of the LIS software in their current implementations. LIS not only consolidates the capabilities of these two systems, but also enables a much larger variety of configurations with respect to horizontal spatial resolution, input datasets and choice of land surface model through 'plugins'. In addition to these capabilities, LIS has also been demonstrated for parameter estimation (Peters-Lidard et al., 2008; Santanello et al., 2007) and data assimilation (Kumar et al., 2008). Examples and case studies

Surface Landing Site Weather Analysis for NASA's Constellation Program

NASA Technical Reports Server (NTRS)

Altino, Karen M.; Burns, K. L.

2008-01-01

Weather information is an important asset for NASA's Constellation Program in developing the next generation space transportation system to fly to the International Space Station, the Moon and, eventually, to Mars. Weather conditions can affect vehicle safety and performance during multiple mission phases ranging from pre-launch ground processing of the Ares vehicles to landing and recovery operations, including all potential abort scenarios. Meteorological analysis is art important contributor, not only to the development and verification of system design requirements but also to mission planning and active ground operations. Of particular interest are the surface weather conditions at both nominal and abort landing sites for the manned Orion capsule. Weather parameters such as wind, rain, and fog all play critical roles in the safe landing of the vehicle and subsequent crew and vehicle recovery. The Marshall Space Flight Center (MSFC) Natural Environments Branch has been tasked by the Constellation Program with defining the natural environments at potential landing zones. This paper wiI1 describe the methodology used for data collection and quality control, detail the types of analyses performed, and provide a sample of the results that cab be obtained.

C, N, P export regimes from headwater catchments to downstream reaches

NASA Astrophysics Data System (ADS)

Dupas, R.; Musolff, A.; Jawitz, J. W.; Rao, P. S.; Jaeger, C. G.; Fleckenstein, J. H.; Rode, M.; Borchardt, D.

2017-12-01

Excessive amounts of nutrients and dissolved organic matter in freshwater bodies affect aquatic ecosystems. In this study, the spatial and temporal variability in nitrate (NO3), dissolved organic carbon (DOC) and soluble reactive phosphorus (SRP) was analyzed in the Selke river continuum from headwaters draining 1 - 3 km² catchments to downstream reaches representing spatially integrated signals from 184 - 456 km² catchments (part of TERENO - Terrestrial Environmental Observatories, in Germany). Three headwater catchments were selected as archetypes of the main landscape units (land use x lithology) present in the Selke catchment. Export regimes in headwater catchments were interpreted in terms of NO3, DOC and SRP land-to-stream transfer processes. Headwater signals were subtracted from downstream signals, with the differences interpreted in terms of in-stream processes and contribution of point-source emissions. The seasonal dynamics for NO3 were opposite those of DOC and SRP in all three headwater catchments, and spatial differences also showed NO3 contrasting with DOC and SRP. These dynamics were interpreted as the result of the interplay of hydrological and biogeochemical processes, for which riparian zones were hypothesized to play a determining role. In the two downstream reaches, NO3 was transported almost conservatively, whereas DOC was consumed and produced in the upper and lower river sections, respectively. The natural export regime of SRP in the three headwater catchments mimicked a point-source signal, which may lead to overestimation of domestic contributions in the downstream reaches. Monitoring the river continuum from headwaters to downstream reaches proved effective to investigate jointly land-to-stream and in-stream transport and transformation processes.

Quantifying Hydrological Ecosystem Services of Various Land Covers and Uses on Small Experimental Catchments within the Panama Canal Watershed: The Agua Salud Project

NASA Astrophysics Data System (ADS)

Crouch, T. D.; Ogden, F. L.; Agua Salud Project

2011-12-01

As a part of the Agua Salud Project, a baseline characterization of hydrologic processes on the small catchment scale (~0.24 to 2.0 km2) is assessed across different land uses and covers typical to rural Panama. The land covers being monitored include a mature secondary forest, a disturbed catchment with a mosaic of various aged secondary growth and agricultural use, an active pasture and a monoculture invasive grass site as experimental controls, and two treated catchments that were recently abandoned pastures converted to teak and native species timber plantations. The catchments are found within Panama's protected Soberania National Park and the adjacent headwaters of the Agua Salud and Mendoza Rivers, all part of the greater Panama Canal Watershed. Using hydrological data from the first two and a half years of the project, three main ecosystem services are observed. The forested area exhibited lower storm event peaks, decreased flashiness, and greater stream flow during the dry season compared to the disturbed mosaic site. Lower hydrograph peaks and flashiness mitigate the risk of substantial flood damage during the major flood events generally seen in Panama between October and December. The mature forest (1.35 km2) catchment has shown lower average flood peaks in comparison to the disturbed site. For storm peaks less than 6 mm/hr, flood peaks are on average 51% lower. For storm peaks greater than 6 mm/hr, flood peaks are approximately 40% lower. In 1998, draft restrictions were imposed in the Panama Canal because of a deficit of dry season water after an El Niño-Southern Oscillation resulted in decreased wet season rainfall. The water that is available during the end of the dry season has the potential to insure the full operation of the Canal during El Niño drought years. Toward the end of the dry season (March through May) our data shows that roughly 34% more water was available during a relatively dry year with respect to antecedent wet season rainfall

NASA Earth Resources Survey Symposium. Volume 1-C: Land use, marine resources

NASA Technical Reports Server (NTRS)

1975-01-01

Articles are presented on the utilization of remote sensing data from NASA programs involving LANDSAT, the Skylab Earth resources experiment package, and aircraft, as well as from other data acquisition programs. Emphasis is placed on land use and marine resources.

Before and After Integrated Catchment Management in a Headwater Catchment: Changes in Water Quality

NASA Astrophysics Data System (ADS)

Hughes, Andrew O.; Quinn, John M.

2014-12-01

Few studies have comprehensively measured the effect on water quality of catchment rehabilitation measures in comparison with baseline conditions. Here we have analyzed water clarity and nutrient concentrations and loads for a 13-year period in a headwater catchment within the western Waikato region, New Zealand. For the first 6 years, the entire catchment was used for hill-country cattle and sheep grazing. An integrated catchment management plan was implemented whereby cattle were excluded from riparian areas, the most degraded land was planted in Pinus radiata, channel banks were planted with poplar trees and the beef cattle enterprise was modified. The removal of cattle from riparian areas without additional riparian planting had a positive and rapid effect on stream water clarity. In contrast, the water clarity decreased in those sub-catchments where livestock was excluded but riparian areas were planted with trees and shrubs. We attribute the decrease in water clarity to a reduction in groundcover vegetation that armors stream banks against preparatory erosion processes. Increases in concentrations of forms of P and N were recorded. These increases were attributed to: (i) the reduction of instream nutrient uptake by macrophytes and periphyton due to increased riparian shading; (ii) uncontrolled growth of a nitrogen fixing weed (gorse) in some parts of the catchment, and (iii) the reduction in the nutrient attenuation capacity of seepage wetlands due to the decrease in their areal coverage in response to afforestation. Our findings highlight the complex nature of the water quality response to catchment rehabilitation measures.

Beyond Impervious: Urban Land-Cover Pattern Variation and Implications for Watershed Management

NASA Astrophysics Data System (ADS)

Beck, Scott M.; McHale, Melissa R.; Hess, George R.

2016-07-01

Impervious surfaces degrade urban water quality, but their over-coverage has not explained the persistent water quality variation observed among catchments with similar rates of imperviousness. Land-cover patterns likely explain much of this variation, although little is known about how they vary among watersheds. Our goal was to analyze a series of urban catchments within a range of impervious cover to evaluate how land-cover varies among them. We then highlight examples from the literature to explore the potential effects of land-cover pattern variability for urban watershed management. High-resolution (1 m2) land-cover data were used to quantify 23 land-cover pattern and stormwater infrastructure metrics within 32 catchments across the Triangle Region of North Carolina. These metrics were used to analyze variability in land-cover patterns among the study catchments. We used hierarchical clustering to organize the catchments into four groups, each with a distinct landscape pattern. Among these groups, the connectivity of combined land-cover patches accounted for 40 %, and the size and shape of lawns and buildings accounted for 20 %, of the overall variation in land-cover patterns among catchments. Storm water infrastructure metrics accounted for 8 % of the remaining variation. Our analysis demonstrates that land-cover patterns do vary among urban catchments, and that trees and grass (lawns) are divergent cover types in urban systems. The complex interactions among land-covers have several direct implications for the ongoing management of urban watersheds.

Impact of land use, soil and DEM databases on surface runoff assessment with GIS decision support tool: A study case on the Briançon vineyard catchment (Gard, France)

NASA Astrophysics Data System (ADS)

Regazzoni, C.; Payraudeau, S.

2012-04-01

Runoff and associated erosion represent a primary mode of mobilization and transfer of pesticides from agricultural lands to watercourses and groundwater. The pesticides toxicity is potentially higher at the headwater catchment scale. These catchments are usually ungauged and characterized by temporary streams. Several mitigation strategies and management practices are currently used to mitigate the pesticides mixtures in agro-ecosystems. Among those practices, Stormwater Wetlands (SW) could be implemented to store surface runoff and to mitigate pesticides loads. The implementation of New Potential Stormwater Wetlands (NPSW) requires a diagnosis of intermittent runoff at the headwater catchment scale. The main difficulty to perform this diagnosis at the headwater catchment scale is to spatially characterize with enough accuracy the landscape components. Indeed, fields and field margins enhance or decrease the runoff and determine the pathways of hortonian overland flow. Land use, soil and Digital Elevation Model databases are systematically used. The question of the respective weight of each of these databases on the uncertainty of the diagnostic results is rarely analyzed at the headwater catchment scale. Therefore, this work focused (i) on the uncertainties of each of these databases and their propagation on the hortonian overland flow modelling, (ii) the methods to improve the accuracy of each database, (iii) the propagation of the databases uncertainties on intermittent runoff modelling and (iv) the impact of modelling cell size on the diagnosis. The model developed was a raster approach of the SCS-CN method integrating re-infiltration processes. The uncertainty propagation was analyzed on the Briançon vineyard catchment (Gard, France, 1400 ha). Based on this study site, the results showed that the geographic and thematic accuracies of regional soil database (1:250 000) were insufficient to correctly simulate the hortonian overland flow. These results have to

Cloud-enabled large-scale land surface model simulations with the NASA Land Information System

NASA Astrophysics Data System (ADS)

Duffy, D.; Vaughan, G.; Clark, M. P.; Peters-Lidard, C. D.; Nijssen, B.; Nearing, G. S.; Rheingrover, S.; Kumar, S.; Geiger, J. V.

2017-12-01

Developed by the Hydrological Sciences Laboratory at NASA Goddard Space Flight Center (GSFC), the Land Information System (LIS) is a high-performance software framework for terrestrial hydrology modeling and data assimilation. LIS provides the ability to integrate satellite and ground-based observational products and advanced modeling algorithms to extract land surface states and fluxes. Through a partnership with the National Center for Atmospheric Research (NCAR) and the University of Washington, the LIS model is currently being extended to include the Structure for Unifying Multiple Modeling Alternatives (SUMMA). With the addition of SUMMA in LIS, meaningful simulations containing a large multi-model ensemble will be enabled and can provide advanced probabilistic continental-domain modeling capabilities at spatial scales relevant for water managers. The resulting LIS/SUMMA application framework is difficult for non-experts to install due to the large amount of dependencies on specific versions of operating systems, libraries, and compilers. This has created a significant barrier to entry for domain scientists that are interested in using the software on their own systems or in the cloud. In addition, the requirement to support multiple run time environments across the LIS community has created a significant burden on the NASA team. To overcome these challenges, LIS/SUMMA has been deployed using Linux containers, which allows for an entire software package along with all dependences to be installed within a working runtime environment, and Kubernetes, which orchestrates the deployment of a cluster of containers. Within a cloud environment, users can now easily create a cluster of virtual machines and run large-scale LIS/SUMMA simulations. Installations that have taken weeks and months can now be performed in minutes of time. This presentation will discuss the steps required to create a cloud-enabled large-scale simulation, present examples of its use, and

Understanding global changes on the land - A potential focus for NASA earth sciences and land remote sensing

NASA Technical Reports Server (NTRS)

Erickson, J. D.; Tuyahov, A. J.; Hogg, H. C.

1983-01-01

Planned NASA contributions to the study of the interaction of living organisms with their physical and chemical environments are discussed. Five major land-related research objectives are stated and the role of remote sensing in achieving them is addressed. The importance of improved sensors and cooperation with domestic and international organizations is stressed.

Analysis of Summer Thunderstorms in Central Alabama Using the NASA Land Information System

NASA Technical Reports Server (NTRS)

James, Robert; Case, Jonathan; Molthan, Andrew; Jedloved, Gary

2010-01-01

Forecasters have difficulty predicting "random" afternoon thunderstorms during the summer months. Differences in soil characteristics could be a contributing factor for storms. The NASA Land Information System (LIS) may assist forecasters in predicting summer convection by identifying boundaries in land characteristics. This project identified case dates during the summer of 2009 by analyzing synoptic weather maps, radar, and satellite data to look for weak atmospheric forcing and disorganized convective development. Boundaries in land characteristics that may have lead to convective initiation in central Alabama were then identified using LIS.

Catchment-scale groundwater recharge and vegetation water use efficiency

NASA Astrophysics Data System (ADS)

Troch, P. A. A.; Dwivedi, R.; Liu, T.; Meira, A.; Roy, T.; Valdés-Pineda, R.; Durcik, M.; Arciniega, S.; Brena-Naranjo, J. A.

2017-12-01

Precipitation undergoes a two-step partitioning when it falls on the land surface. At the land surface and in the shallow subsurface, rainfall or snowmelt can either runoff as infiltration/saturation excess or quick subsurface flow. The rest will be stored temporarily in the root zone. From the root zone, water can leave the catchment as evapotranspiration or percolate further and recharge deep storage (e.g. fractured bedrock aquifer). Quantifying the average amount of water that recharges deep storage and sustains low flows is extremely challenging, as we lack reliable methods to quantify this flux at the catchment scale. It was recently shown, however, that for semi-arid catchments in Mexico, an index of vegetation water use efficiency, i.e. the Horton index (HI), could predict deep storage dynamics. Here we test this finding using 247 MOPEX catchments across the conterminous US, including energy-limited catchments. Our results show that the observed HI is indeed a reliable predictor of deep storage dynamics in space and time. We further investigate whether the HI can also predict average recharge rates across the conterminous US. We find that the HI can reliably predict the average recharge rate, estimated from the 50th percentile flow of the flow duration curve. Our results compare favorably with estimates of average recharge rates from the US Geological Survey. Previous research has shown that HI can be reliably estimated based on aridity index, mean slope and mean elevation of a catchment (Voepel et al., 2011). We recalibrated Voepel's model and used it to predict the HI for our 247 catchments. We then used these predicted values of the HI to estimate average recharge rates for our catchments, and compared them with those estimated from observed HI. We find that the accuracies of our predictions based on observed and predicted HI are similar. This provides an estimation method of catchment-scale average recharge rates based on easily derived catchment

Catchment heterogeneity controls emergent archetype concentration-discharge relationships

NASA Astrophysics Data System (ADS)

Musolff, A.; Fleckenstein, J. H.; Rao, P. S.; Jawitz, J. W.

2017-12-01

Relationships between in-stream dissolved solute concentrations (C) and discharge (Q) are often-used indicators of catchment-scale processes and their interference with human activities. Here we analyze observational C-Q relationships from 61 catchments and 8 different solutes across a wide range of land-uses and discharge regimes. This analysis is combined with a parsimonious stochastic modeling approach to test how C-Q relationships arise from spatial heterogeneity in catchment solute sources coupled with different timescales of biogeochemical reactions. The observational data exhibit archetypical dilution, enrichment, and constant C-Q patterns. Moreover, with land-use intensification we find decreasing C variability relative to Q variability (chemostatic export regime). Our model indicates that the dominant driver of emergent C-Q patterns was structured heterogeneity of solute sources implemented as correlation of source concentration to travel time. Regardless of the C-Q pattern, with decreasing source heterogeneity we consistently find lower variability in C than in Q and a dominance of chemostatic export regimes. Here, the variance in exported loads is determined primarily by variance of Q. We conclude that efforts to improve stream water quality and ecological integrity in intensely managed catchments should lead away from landscape homogenization by introducing structured source heterogeneity. References: Musolff, A., J. H. Fleckenstein, P. S. C. Rao, and J. W. Jawitz (2017), Emergent archetype patterns of coupled hydrologic and biogeochemical responses in catchments, Geophys. Res. Lett., 44(9), 4143-4151, doi: 10.1002/2017GL072630.

Greenhouse gas fluxes of grazed and hayed wetland catchments in the U.S. Prairie Pothole Ecoregion

USGS Publications Warehouse

Finocchiaro, Raymond G.; Tangen, Brian A.; Gleason, Robert A.

2014-01-01

Wetland catchments are major ecosystems in the Prairie Pothole Region (PPR) and play an important role in greenhouse gases (GHG) flux. However, there is limited information regarding effects of land-use on GHG fluxes from these wetland systems. We examined the effects of grazing and haying, two common land-use practices in the region, on GHG fluxes from wetland catchments during 2007 and 2008. Fluxes of methane (CH4), nitrous oxide (N2O), and carbon dioxide (CO2), along with soil water content and temperature, were measured along a topographic gradient every other week during the growing season near Ipswich, SD, USA. Closed, opaque chambers were used to measure fluxes of soil and plant respiration from native sod catchments that were grazed or left idle, and from recently restored catchments which were seeded with native plant species; half of these catchments were hayed once during the growing season. Catchments were adjacent to each other and had similar soils, soil nitrogen and organic carbon content, precipitation, and vegetation. When compared with idle catchments, grazing as a land-use had little effect on GHG fluxes. Likewise, haying had little effect on fluxes of CH4 and N2O compared with non-hayed catchments. Haying, however, did have a significant effect on combined soil and vegetative CO2 flux in restored wetland catchments owing to the immediate and comprehensive effect haying has on plant productivity. This study also examined soil conditions that affect GHG fluxes and provides cumulative annual estimates of GHG fluxes from wetland catchment in the PPR.

A catchment scale water balance model for FIFE

NASA Technical Reports Server (NTRS)

Famiglietti, J. S.; Wood, E. F.; Sivapalan, M.; Thongs, D. J.

1992-01-01

A catchment scale water balance model is presented and used to predict evaporation from the King's Creek catchment at the First ISLSCP Field Experiment site on the Konza Prairie, Kansas. The model incorporates spatial variability in topography, soils, and precipitation to compute the land surface hydrologic fluxes. A network of 20 rain gages was employed to measure rainfall across the catchment in the summer of 1987. These data were spatially interpolated and used to drive the model during storm periods. During interstorm periods the model was driven by the estimated potential evaporation, which was calculated using net radiation data collected at site 2. Model-computed evaporation is compared to that observed, both at site 2 (grid location 1916-BRS) and the catchment scale, for the simulation period from June 1 to October 9, 1987.

Predictive Modeling for NASA Entry, Descent and Landing Missions

NASA Technical Reports Server (NTRS)

Wright, Michael

2016-01-01

Entry, Descent and Landing (EDL) Modeling and Simulation (MS) is an enabling capability for complex NASA entry missions such as MSL and Orion. MS is used in every mission phase to define mission concepts, select appropriate architectures, design EDL systems, quantify margin and risk, ensure correct system operation, and analyze data returned from the entry. In an environment where it is impossible to fully test EDL concepts on the ground prior to use, accurate MS capability is required to extrapolate ground test results to expected flight performance.

Spatio-temporal dynamics of sediment sources in a peri-urban Mediterranean catchment

NASA Astrophysics Data System (ADS)

Ferreira, Carla; Walsh, Rory; Blake, William; Kikuchi, Ryunosuke; Ferreira, António

2017-04-01

Sediment fluxes driven by hydrological processes lead to natural soil losses, but human activities, such as urbanization, influence hydrology and promote erosion, altering the landscape and sediment fluxes. In peri-urban areas, comprising a mixture of semi-natural and man-made land-uses, understanding sediment fluxes is still a research challenge. This study investigates spatial and temporal dynamics of fluvial sediments in a rapidly urbanizing catchment. Specific objectives are to understand the main sources of sediments relating to different types of urban land disturbance, and their variability driven by (i) weather, season and land-use changes through time, and (ii) sediment particle size. The study was carried out Ribeira dos Covões, a peri-urban catchment (6.2km2) in central Portugal. The climate is humid Mediterranean, with mean annual temperature and rainfall of 15˚ C and 892 mm, respectively. The geology comprises sandstone (56%), limestone (41%) and alluvial deposits (3%). The catchment has an average slope of 9˚ , but includes steep slopes of up to 46˚ . The land-use is a complex mosaic of woodland (56%), urban (40%) and agricultural (4%) land parcels, resulting from urbanization occurring progressively since 1973. Urbanization since 2010 has mainly comprised the building of a major road, covering 1% of the catchment area, and the ongoing construction of an enterprise park, occupying 5% of the catchment. This study uses a multi-proxy sediment fingerprinting approach, based on X-Ray Fluorescence (XRF) analyses to characterize the elemental geochemistry of sediments collected within the stream network after three storm events in 2012 and 2015. A range of statistical techniques, including hierarchical cluster analysis, was used to identify discriminant sediment properties and similarities between fine bed-sediment samples of tributaries and downstream sites. Quantification of sediment supply from upstream sub-catchments was undertaken using a Bayesian

Legacy nutrient dynamics and patterns of catchment response under changing land use and management

NASA Astrophysics Data System (ADS)

Attinger, S.; Van, M. K.; Basu, N. B.

2017-12-01

Watersheds are complex heterogeneous systems that store, transform, and release water and nutrients under a broad distribution of both natural and anthropogenic controls. Many current watershed models, from complex numerical models to simpler reservoir-type models, are considered to be well-developed in their ability to predict fluxes of water and nutrients to streams and groundwater. They are generally less adept, however, at capturing watershed storage dynamics. In other words, many current models are run with an assumption of steady-state dynamics, and focus on nutrient flows rather than changes in nutrient stocks within watersheds. Although these commonly used modeling approaches may be able to adequately capture short-term watershed dynamics, they are unable to represent the clear nonlinearities or hysteresis responses observed in watersheds experiencing significant changes in nutrient inputs. To address such a lack, we have, in the present work, developed a parsimonious modeling approach designed to capture long-term catchment responses to spatial and temporal changes in nutrient inputs. In this approach, we conceptualize the catchment as a biogeochemical reactor that is driven by nutrient inputs, characterized internally by both biogeochemical degradation and residence or travel time distributions, resulting in a specific nutrient output. For the model simulations, we define a range of different scenarios to represent real-world changes in land use and management implemented to improve water quality. We then introduce the concept of state-space trajectories to describe system responses to these potential changes in anthropogenic forcings. We also increase model complexity, in a stepwise fashion, by dividing the catchment into multiple biogeochemical reactors, coupled in series or in parallel. Using this approach, we attempt to answer the following questions: (1) What level of model complexity is needed to capture observed system responses? (2) How can we

Influences of upland and riparian land use patterns on stream biotic integrity

USGS Publications Warehouse

Snyder, C.D.; Young, J.A.; Villella, R.; Lemarie, D.P.

2003-01-01

We explored land use, fish assemblage structure, and stream habitat associations in 20 catchments in Opequon Creek watershed, West Virginia. The purpose was to determine the relative importance of urban and agriculture land use on stream biotic integrity, and to evaluate the spatial scale (i.e., whole-catchment vs riparian buffer) at which land use effects were most pronounced. We found that index of biological integrity (IBI) scores were strongly associated with extent of urban land use in individual catchments. Sites that received ratings of poor or very poor based on IBI scores had > 7% of urban land use in their respective catchments. Habitat correlations suggested that urban land use disrupted flow regime, reduced water quality, and altered stream channels. In contrast, we found no meaningful relationship between agricultural land use and IBI at either whole-catchment or riparian scales despite strong correlations between percent agriculture and several important stream habitat measures, including nitrate concentrations, proportion of fine sediments in riffles, and the abundance of fish cover. We also found that variation in gradient (channel slope) influenced responses of fish assemblages to land use. Urban land use was more disruptive to biological integrity in catchments with steeper channel slopes. Based on comparisons of our results in the topographically diverse Opequon Creek watershed with results from watersheds in flatter terrains, we hypothesize that the potential for riparian forests to mitigate effects of deleterious land uses in upland portions of the watershed is inversely related to gradient.

Understanding fine sediment and phosphorous delivery in upland catchments

NASA Astrophysics Data System (ADS)

Perks, M. T.; Reaney, S. M.

2013-12-01

The uplands of UK are heavily impacted by land management including; farming and forestry operations, moorland burning, peat extraction, metal mining, artificial drainage and channelisation. It has been demonstrated that such land management activity may modify hillslope processes, resulting in enhanced runoff generation and changing the spatial distribution and magnitude of erosion. Resultantly, few upland river systems of the UK are operating in a natural state, with land management activity often resulting in increased fluxes of suspended sediment (< 2 mm) and associated pollutants (such as phosphorous). Most recent Environment Agency (EA) data reveals that 60% of monitored water bodies within upland areas of the UK are currently at risk of failing the Water Framework Directive (WFD) due to poor ecological status. In order to prevent the continual degradation of many upland catchments, riverine systems and their diverse ecosystems, a range of measures to control diffuse pollution will need to be implemented. Future mitigation options and measures in the UK may be tested and targeted through the EA's catchment pilot scheme; DEFRA's Demonstration Test Catchment (DTC) programmes and through the catchment restoration fund. However, restoring the physical and biological processes of past conditions in inherently sensitive upland environments is extremely challenging requiring the development of a solid evidence base to determine the effectiveness of resource allocation and to enable reliable and transparent decisions to be made about future catchment operations. Such evidence is rarely collected, with post-implementation assessments often neglected. This paper presents research conducted in the Morland sub-catchment of the River Eden within Cumbria; UK. 80% of this headwater catchment is in upland areas and is dominated by improved grassland and rough grazing. The catchment is heavily instrumented with a range of hydro-meteorological equipment. A high-tech monitoring

Soil moisture controlled runoff mechanisms in a small agricultural catchment in Austria.

NASA Astrophysics Data System (ADS)

Vreugdenhil, Mariette; Szeles, Borbala; Silasari, Rasmiaditya; Hogan, Patrick; Oismueller, Markus; Strauss, Peter; Wagner, Wolfgang; Bloeschl, Guenter

2017-04-01

Understanding runoff generation mechanisms is pivotal for improved estimation of floods in small catchments. However, this requires in situ measurements with a high spatial and temporal resolution of different land surface parameters, which are rarely available distributed over the catchment scale and for a long period. The Hydrological Open Air Laboratory (HOAL) is a hydrological observatory which comprises a complex agricultural catchment, covering 66 ha. Due to the agricultural land use and low permeability of the soil part of the catchment was tile drained in the 1940s. The HOAL is equipped with an extensive soil moisture network measuring at 31 locations, 4 rain gauges and 12 stream gauges. By measuring with so many sensors in a complex catchment, the collected data enables the investigation of multiple runoff mechanisms which can be observed simultaneously in different parts of the catchment. The aim of this study is to identify and characterize different runoff mechanisms and the control soil moisture dynamics exert on them. As a first step 72 rainfall events were identified within the period 2014-2015. By analyzing event discharge response, measured at the different stream gauges, and root zone soil moisture, four different runoff mechanisms are identified. The four mechanisms exhibit contrasting soil moisture-discharge relationships. In the presented study we characterize the runoff response types by curve-fitting the discharge response to the soil moisture state. The analysis provides insights in the main runoff processes occurring in agricultural catchments. The results of this study a can be of assistance in other catchments to identify catchment hydrologic response.

Tropical Montane Cloud Forests: Hydrometeorological variability in three neighbouring catchments with different forest cover

NASA Astrophysics Data System (ADS)

Ramírez, Beatriz H.; Teuling, Adriaan J.; Ganzeveld, Laurens; Hegger, Zita; Leemans, Rik

2017-09-01

Mountain areas are characterized by a large heterogeneity in hydrological and meteorological conditions. This heterogeneity is currently poorly represented by gauging networks and by the coarse scale of global and regional climate and hydrological models. Tropical Montane Cloud Forests (TMCFs) are found in a narrow elevation range and are characterized by persistent fog. Their water balance depends on local and upwind temperatures and moisture, therefore, changes in these parameters will alter TMCF hydrology. Until recently the hydrological functioning of TMCFs was mainly studied in coastal regions, while continental TMCFs were largely ignored. This study contributes to fill this gap by focusing on a TMCF which is located on the northern eastern Andes at an elevation of 1550-2300 m asl, in the Orinoco river basin highlands. In this study, we describe the spatial and seasonal meteorological variability, analyse the corresponding catchment hydrological response to different land cover, and perform a sensitivity analysis on uncertainties related to rainfall interpolation, catchment area estimation and streamflow measurements. Hydro-meteorological measurements, including hourly solar radiation, temperature, relative humidity, wind speed, precipitation, soil moisture and streamflow, were collected from June 2013 to May 2014 at three gauged neighbouring catchments with contrasting TMCF/grassland cover and less than 250 m elevation difference. We found wetter and less seasonally contrasting conditions at higher elevations, indicating a positive relation between elevation and fog or rainfall persistence. This pattern is similar to that of other eastern Andean TMCFs, however, the study site had higher wet season rainfall and lower dry season rainfall suggesting that upwind contrasts in land cover and moisture can influence the meteorological conditions at eastern Andean TMCFs. Contrasting streamflow dynamics between the studied catchments reflect the overall system response

Carbon redistribution by erosion processes in an intensively disturbed catchment

NASA Astrophysics Data System (ADS)

Boix-Fayos, Carolina; Martínez-Mena, María; Pérez Cutillas, Pedro; de Vente, Joris; Barberá, Gonzalo G.; Mosch, Wouter; Navarro Cano, Jose Antonio; Gaspar, Leticia; Navas, Ana

2016-04-01

Understanding how organic carbon moves with sediments along the fluvial system is crucial to close catchment scale carbon budgets. Especially challenging is the analysis of organic carbon dynamics during fluvial transport in heterogeneous, fragile and disturbed environments with ephemeral and intense hydrological pulses, typical of Mediterranean conditions. This paper explores the catchment scale organic carbon redistribution by lateral flows in extreme Mediterranean environmental conditions from a geomorphological perspective. The study area is a catchment (Cárcavo) in SE Spain with a semiarid climate, erodible lithologies, shallow soils, and highly disturbed by agricultural terraces, land levelling, reforestations and construction of check-dams. To increase understanding of erosion induced catchment scale organic carbon redistribution, we studied the subcatchments of 8 check-dams distributed along the catchment main channel in detail. We determined 137Cs, physicochemical characteristics and organic carbon pools of soils and sediments deposited behind each check-dam, performed spatial analysis of properties of the catchment and buffer areas around check-dams, and carried out geomorphological analysis of the slope-channel connections. Soils showed very low Total Organic Carbon (TOC) values oscillating between 15.2 and 4.4 g Kg-1 for forest and agricultural soils, respectively. Sediments mobilized by erosion were poor in TOC compared to the eroded (forest) soils (6.6±0.7 g Kg-1), and the redistribution of organic carbon through the catchment, especially of the Mineral Associated Organic Carbon (MAC) pool, showed the same pattern as clay particles and 137Cs. The TOC erosion rates (0.031±0.03 Mg ha-1 y-1) were comparable to others reported for subhumid Mediterranean catchments and to those modelled worldwide for pasture land. Those lateral fluxes were equivalent to 10.4 % of the TOC stock from the topsoil at the moment of the check-dam construction and

In Brief: NASA's Phoenix spacecraft lands on Mars

NASA Astrophysics Data System (ADS)

Showstack, Randy; Kumar, Mohi

2008-06-01

After a 9.5-month, 679-million-kilometer flight from Florida, NASA's Phoenix spacecraft made a soft landing in Vastitas Borealis in Mars's northern polar region on 25 May. The lander, whose camera already has returned some spectacular images, is on a 3-month mission to examine the area and dig into the soil of this site-chosen for its likelihood of having frozen water near the surface-and analyze samples. In addition to a robotic arm and robotic arm camera, the lander's instruments include a surface stereo imager; thermal and evolved-gas analyzer; microscopy, electrochemistry, and conductivity analyzer; and a meteorological station that is tracking daily weather and seasonal changes.

Describing Ecosystem Complexity through Integrated Catchment Modeling

NASA Astrophysics Data System (ADS)

Shope, C. L.; Tenhunen, J. D.; Peiffer, S.

2011-12-01

Land use and climate change have been implicated in reduced ecosystem services (ie: high quality water yield, biodiversity, and agricultural yield. The prediction of ecosystem services expected under future land use decisions and changing climate conditions has become increasingly important. Complex policy and management decisions require the integration of physical, economic, and social data over several scales to assess effects on water resources and ecology. Field-based meteorology, hydrology, soil physics, plant production, solute and sediment transport, economic, and social behavior data were measured in a South Korean catchment. A variety of models are being used to simulate plot and field scale experiments within the catchment. Results from each of the local-scale models provide identification of sensitive, local-scale parameters which are then used as inputs into a large-scale watershed model. We used the spatially distributed SWAT model to synthesize the experimental field data throughout the catchment. The approach of our study was that the range in local-scale model parameter results can be used to define the sensitivity and uncertainty in the large-scale watershed model. Further, this example shows how research can be structured for scientific results describing complex ecosystems and landscapes where cross-disciplinary linkages benefit the end result. The field-based and modeling framework described is being used to develop scenarios to examine spatial and temporal changes in land use practices and climatic effects on water quantity, water quality, and sediment transport. Development of accurate modeling scenarios requires understanding the social relationship between individual and policy driven land management practices and the value of sustainable resources to all shareholders.

Modeling the influence of long term human-induced land use conversion on sediment fluxes and carbon dynamics at the catchment scale

NASA Astrophysics Data System (ADS)

Bouchoms, Samuel; Van Oost, Kristof; Vanacker, Veerle

2014-05-01

Over the past 20 years, there has been increasing evidence of the strong impact of human activities on the landscape, specifically on soil erosion due to the removal of natural vegetation cover for agricultural and urban purposes. The results question the widespread hypothesis of a steady state landscape since it appears that the balance between soil production and erosion may be broken altering the interactions between chemical, physical and biological processes in both soil and landscape system. Yet, the relationship between this accelerated erosion and the carbon dynamics at the landscape scale remains an important area of investigation. Recent attempts to combine geomorphic models, soil redistribution and carbon dynamic has proved themselves valuable in term of supporting the importance of lateral fluxes as a crucial control of carbon dynamic at the landscape scale. We use the SPEROS LT model, a modified version of SPEROS-C which includes dynamic land use and soil physical properties, to assess the impact of historical land use conversion on sediment and carbon fluxes in the Dijle catchment. This particular location has experienced a significant human impact since the Roman period, undergoing heavy deforestation and expansion of agricultural lands followed by a period of abandonment. The last 400 to 500 years saw a dramatic increase in the intensity of land use conversion associated to population growth leading to forest cleaning and urbanization. Our main objective is to validate the combined geomorphic and soil carbon turnover process descriptions of the model. Historical land use proportions are based on existing literature estimations and spatial assignation of the land conversion relies on simple allocation rules based on criteria such as slope or soil texture. Land use scenarios are constructed for the last 2000 years. We confront the model results with observations and perform a sensitivity analysis. The results indicate that the general trends in

Channel response to increased and decreased bedload supply from land use change: contrasts between two catchments

NASA Astrophysics Data System (ADS)

Kondolf, G. M.; Piégay, H.; Landon, N.

2002-06-01

The catchments of Pine Creek, Idaho, USA (200 km 2), and the Drôme River in the Drôme Department, France (1640 km 2), illustrate contrasting changes in land use, bedload sediment production, and channel response. Hard-rock mining began in the catchment of Pine Creek near the end of the 19th century and, together with road construction, timber harvest, and historically heavy grazing of uplands, resulted in increased tributary bedload yield. Increased bedload migrating to the channel, combined with removal of large cedar trees on the floodplain, resulted in channel instability, which propagated downstream over a period of decades. On many reaches of Pine Creek, active channel width has increased by over 50% since 1933. Over roughly the same time period, the Drôme River catchment was extensively reforested (after at least one century of denudation and heavy grazing) and numerous check dams were constructed on torrents to reduce erosion. As a result, the Drôme River has experienced a reduction in bedload sediment supply since the late 19th century. In addition, gravel has been extracted from some reaches. Consequently, the channel has degraded and gravel bars have been colonized with woody riparian vegetation. Channel widths in wide, braided reaches decreased from 1947 to 1970 by 60%. On Pine Creek, channel instability has resulted in bank erosion (exposing contaminated mine tailings) and increased flood hazard. On the Drôme River, degradation has undermined bridges and embankments, and lowered the water table in areas dependent on groundwater for irrigation, resulting in loss of 6 million m 3 of groundwater storage since 1960. Though they differ in drainage area by nearly an order of magnitude, Pine Creek and the Drôme River provide an excellent contrast in that they represent two sides of an epicycle of alluvial sedimentation set off in each case by land disturbance. In both cases, the most recent channel changes, though in opposite directions, were viewed as

Determination of dominant sources of nitrate contamination in transboundary (Russian Federation/Ukraine) catchment with heterogeneous land use.

PubMed

Vystavna, Y; Diadin, D; Grynenko, V; Yakovlev, V; Vergeles, Y; Huneau, F; Rossi, P M; Hejzlar, J; Knöller, K

2017-09-18

Nitrate contamination of surface water and shallow groundwater was studied in transboundary (Russia/Ukraine) catchment with heterogeneous land use. Dominant sources of nitrate contamination were determined by applying a dual δ 15 N-NO 3 and δ 18 O-NO 3 isotope approach, multivariate statistics, and land use analysis. Nitrate concentration was highly variable from 0.25 to 22 mg L -1 in surface water and from 0.5 to 100 mg L -1 in groundwater. The applied method indicated that sewage to surface water and sewage and manure to groundwater were dominant sources of nitrate contamination. Nitrate/chloride molar ratio was added to support the dual isotope signature and indicated the contribution of fertilizers to the nitrate content in groundwater. Groundwater temperature was found to be an additional indicator of manure and sewerage leaks in the shallow aquifer which has limited protection and is vulnerable to groundwater pollution.

An integrated modelling and multicriteria analysis approach to managing nitrate diffuse pollution: 2. A case study for a chalk catchment in England.

PubMed

Koo, B K; O'Connell, P E

2006-04-01

The site-specific land use optimisation methodology, suggested by the authors in the first part of this two-part paper, has been applied to the River Kennet catchment at Marlborough, Wiltshire, UK, for a case study. The Marlborough catchment (143 km(2)) is an agriculture-dominated rural area over a deep chalk aquifer that is vulnerable to nitrate pollution from agricultural diffuse sources. For evaluation purposes, the catchment was discretised into a network of 1 kmx1 km grid cells. For each of the arable-land grid cells, seven land use alternatives (four arable-land alternatives and three grassland alternatives) were evaluated for their environmental and economic potential. For environmental evaluation, nitrate leaching rates of land use alternatives were estimated using SHETRAN simulations and groundwater pollution potential was evaluated using the DRASTIC index. For economic evaluation, economic gross margins were estimated using a simple agronomic model based on nitrogen response functions and agricultural land classification grades. In order to see whether the site-specific optimisation is efficient at the catchment scale, land use optimisation was carried out for four optimisation schemes (i.e. using four sets of criterion weights). Consequently, four land use scenarios were generated and the site-specifically optimised land use scenario was evaluated as the best compromise solution between long term nitrate pollution and agronomy at the catchment scale.

Assessment of soil organic carbon fractions and carbon management index under different land use types in Olesharo Catchment, Narok County, Kenya.

PubMed

Sainepo, Bernice M; Gachene, Charles K; Karuma, Anne

2018-02-12

The changes in land use and land cover have a strong effect on the total soil organic carbon, its fractions and its overall soil health. This study carried out in Olesharo Catchment, Kenya, was to quantify the differences in total organic carbon (TOC), particulate organic carbon (POC), mineral organic carbon (MOC) and carbon management index (CMI) among four land use types: grasslands, shrublands, agricultural lands and barelands. It was also purported to evaluate the use of CMI as an indicator for soil degradation or improvement in response to land use and land cover changes. The results of the study show that the mean values of TOC, POC and MOC are significantly different between land use types. Thus, shrublands have significantly higher TOC (22.26 g kg -1 ) than grasslands (10.29 g kg -1 ) and bare lands (7.56 g kg -1 ). They also have significantly higher POC (7.79 g kg -1 ) and MOC (10.04 g kg -1 ) than all the other land use types. The agricultural lands have higher CMI than grasslands (53% vs 41% relative to shrublands) suggesting that grasslands face serious degradation through overgrazing. This study shows that different land use types have an influence on soil organic carbon pools, and consequently on the CMI, the CMI could be used as an indicator for soil degradation or improvement in response to land use and land cover changes.

Influence of landscape mosaic on streamflow of a peri-urban catchment under Mediterranean climate

NASA Astrophysics Data System (ADS)

Ferreira, Carla; Walsh, Rory; Ferreira, António

2017-04-01

Peri-urban areas tend to be characterized by patchy landscape mosaics of different land-uses. Although the impact of land-use changes on catchment hydrology have been widely investigated, the impact of mixed land-use patterns on the streamflow of peri-urban areas is still poorly understood. This study aims to (i) explore and quantify streamflow delivery from sub-catchments characterized by distinct landscape mosaics; (ii) assess the impact of different urbanization styles on hydrograph properties; and (iii) explore the influence of urbanization type on flow connectivity and stream discharge. The study was carried out in Ribeira dos Covões, a small (6.2km2) peri-urban catchment in central Portugal. The climate is Mediterranean, with a mean annual rainfall of 892mm. Catchment geology comprises sandstone (56%), limestone (41%) and alluvial deposits (3%). Soils developed on sandstone are generally deep (>3m) Fluvisols and Podsols, whereas on limestone the Leptic Cambisols are typically shallow (<0.4m). Forest is the dominant land-use (56%), but urban areas cover an extensive area (40%), whereas agricultural land has declined to a very small area (4%). The urban area comprises contrasting urban styles, notably older discontinuous urban areas with buildings separated by gardens of low population density (<25 inhabitants km-2), and recent well-defined continuous urban cores dominated by apartment blocks and of high population density (9900 inhabitants km-2). The study uses hydrological data recorded over three hydrological years, starting in November 2010, in a monitoring network comprising eight streamflow gauging stations (instrumented with water level recorders) and five rainfall gauges. The gauging stations provide information on the discharge response to rainstorms of the catchment outlet and upstream sub-catchments of different size, urban pattern (in terms of percentage urban land-use and impervious area, distance to the stream network, and storm water management

Tracing crop-specific sediment sources in agricultural catchments

NASA Astrophysics Data System (ADS)

Blake, William H.; Ficken, Katherine J.; Taylor, Philip; Russell, Mark A.; Walling, Desmond E.

2012-02-01

A Compound Specific Stable Isotope (CSSI) sediment tracing approach is evaluated for the first time in an agricultural catchment setting against established geochemical fingerprinting techniques. The work demonstrates that novel CSSI techniques have the potential to provide important support for soil resource management policies and inform sediment risk assessment for the protection of aquatic habitats and water resources. Analysis of soil material from a range of crop covers in a mixed land-use agricultural catchment shows that the carbon CSSI signatures of particle-reactive fatty acids label surface agricultural soil with distinct crop-specific signatures, thus permitting sediment eroded from each land-cover to be tracked downstream. High resolution sediment sampling during a storm event and analysis for CSSI and conventional geochemical fingerprints elucidated temporal patterns of sediment mobilisation under different crop regimes and the specific contribution that each crop type makes to downstream sediment load. Pasture sources (65% of the catchment area) dominated the sediment load but areal yield (0.13 ± 0.02 t ha - 1 ) was considerably less than that for winter wheat (0.44 ± 0.15 t ha - 1 ). While temporal patterns in crop response matched runoff and erosion response predictions based on plot-scale rainfall simulation experiments, comparison of biomarker and geochemical fingerprinting data indicated that the latter overestimated cultivated land inputs to catchment sediment yield due to inability to discriminate temporary pasture (in rotation) from cultivated land. This discrepancy, however, presents an opportunity since combination of the two datasets revealed the extremely localised nature of erosion from permanent pasture fields in this system (estimated at up to 0.5 t ha - 1 ). The novel use of CSSI and geochemical tracers in tandem provided unique insights into sediment source dynamics that could not have been derived from each method alone. Research

Impact of landuse/land cover change on run-off in the catchment of a hydro power project

NASA Astrophysics Data System (ADS)

Khare, Deepak; Patra, Diptendu; Mondal, Arun; Kundu, Sananda

2017-05-01

The landuse/land cover change and rainfall have a significant influence on the hydrological response of the river basins. The run-off characteristics are changing naturally due to reduction of initial abstraction that increases the run-off volume. Therefore, it is necessary to quantify the changes in the run-off characteristics of a catchment under the influence of changed landuse/land cover. Soil conservation service model has been used in the present study to analyse the impact of various landuse/land cover (past, present and future time period) change in the run-off characteristics of a part of Narmada basin at the gauge discharge site of Mandaleswar in Madhya Pradesh, India. Calculated run-off has been compared with the observed run-off data for the study. The landuse/land cover maps of 1990, 2000 and 2009 have been prepared by digital classification method with proper accuracy using satellite imageries. The impact of the run-off change on hydro power potential has been assessed in the study along with the estimation of the future changes in hydro power potential. Five types of conditions (+10, +5 %, average, -5, -10 % of average rainfall) have been applied with 90 and 75 % dependability status. The generated energy will be less in 90 % dependable flow in respect to the 75 % dependable flow. This work will be helpful for future planning related to establishment of hydropower setup.

Using a Budyko Derived Index to Evaluate the Internal Hydrological Variability of Catchments in Complex Terrain

NASA Astrophysics Data System (ADS)

Dominguez, M.

2017-12-01

Headwater catchments in complex terrain typically exhibit significant variations in microclimatic conditions across slopes. This microclimatic variability in turn, modifies land surface properties presumably altering the hydrologic dynamics of these catchments. The extent to which differences in microclimate and land cover dictate the partition of water and energy fluxes within a catchment is still poorly understood. In this study, we attempt to do an assessment of the effects of aspect, elevation and latitude (which are the principal factors that define microclimate conditions) on the hydrologic behavior of the hillslopes within catchments with complex terrain. Using a distributed hydrologic model on a number of catchments at different latitudes, where data is available for calibration and validation, we estimate the different components of the water balance to obtain the aridity index (AI = PET/P) and the evaporative index (EI = AET/P) of each slope for a number of years. We use Budyko's curve as a framework to characterize the inter-annual variability in the hydrologic response of the hillslopes in the studied catchments, developing a hydrologic sensitivity index (HSi) based on the relative change in Budyko's curve components (HSi=ΔAI/ΔEI). With this method, when the HSi values of a given hillslope are larger than 1 the hydrologic behavior of that part of the catchment is considered sensitive to changes in climatic conditions, while values approaching 0 would indicate the opposite. We use this approach as a diagnostic tool to discern the effect of aspect, elevation, and latitude on the hydrologic regime of the slopes in complex terrain catchments and to try to explain observed patterns of land cover conditions on these types of catchments.

Entry, Descent, and Landing Aerothermodynamics: NASA Langley Experimental Capabilities and Contributions

NASA Technical Reports Server (NTRS)

Hollis, Brian R.; Berger, Karen T.; Berry, Scott A.; Bruckmann, Gregory J.; Buck, Gregory M.; DiFulvio, Michael; Horvath, Thomas J.; Liechty, Derek S.; Merski, N. Ronald; Murphy, Kelly J.;

Land susceptibility to soil erosion in Orashi Catchment, Nnewi South, Anambra State, Nigeria

NASA Astrophysics Data System (ADS)

Odunuga, Shakirudeen; Ajijola, Abiodun; Igwetu, Nkechi; Adegun, Olubunmi

2018-02-01

Soil erosion is one of the most critical environmental hazards that causes land degradation and water quality challenges. Specifically, this phenomenon has been linked, among other problems, to river sedimentation, groundwater pollution and flooding. This paper assesses the susceptibility of Orashi River Basin (ORB) to soil erosion for the purpose of erosion control measures. Located in the South Eastern part of Nigeria, the ORB which covers approximately 413.61 km2 is currently experiencing one of the fastest population growth rate in the region. Analysis of the soil erosion susceptibility of the basin was based on four factors including; rainfall, Land use/Land cover change (LULC), slope and soil erodibility factor (k). The rainfall was assumed to be a constant and independent variable, slope and soil types were categorised into ten (10) classes each while the landuse was categorised into five classes. Weight was assigned to the classes based on the degree of susceptibility to erosion. An overlay of the four variables in a GIS environment was used to produce the basin susceptibility to soil erosion. This was based on the weight index of each factors. The LULC analysis revealed that built-up land use increased from 26.49 km2 (6.4 %) in year 1980 to 79.24 km2 (19.16 %) in 2015 at an average growth rate of 1.51 km2 per annum while the light forest decreased from 336.41 km2 (81.33 %) in 1980 to 280.82 km2 (67.89 %) in 2015 at an average rate 1.59 km2 per annum. The light forest was adjudged to have the highest land cover soil erosion susceptibility. The steepest slope ranges between 70 and 82° (14.34 % of the total land area) and was adjudged to have the highest soil susceptibility to erosion. The total area covered of the loamy soil is 112.37 km2 (27.07 %) with erodibility of 0.7. In all, the overlay of all the variables revealed that 106.66 km2 (25.70 %) and 164.80 km2 (39.7 %) of the basin has a high and very high susceptibility to soil erosion. The over 50

Earth land landing alternatives: Lunar transportation system

NASA Technical Reports Server (NTRS)

Meyerson, Robert

1992-01-01

The objectives of this study are as follows: (1) develop a landing option such that it is a viable trade option for future NASA missions; (2) provide NASA programs with solid technical support in the landing systems area; (3) develop the technical staff; and (4) advance the state of landing systems technology to apply to future NASA missions. All results are presented in viewgraph format.

Predicting diffuse microbial pollution risk across catchments: The performance of SCIMAP and recommendations for future development.

PubMed

Porter, Kenneth D H; Reaney, Sim M; Quilliam, Richard S; Burgess, Chris; Oliver, David M

2017-12-31

Microbial pollution of surface waters in agricultural catchments can be a consequence of poor farm management practices, such as excessive stocking of livestock on vulnerable land or inappropriate handling of manures and slurries. Catchment interventions such as fencing of watercourses, streamside buffer strips and constructed wetlands have the potential to reduce faecal pollution of watercourses. However these interventions are expensive and occupy valuable productive land. There is, therefore, a requirement for tools to assist in the spatial targeting of such interventions to areas where they will have the biggest impact on water quality improvements whist occupying the minimal amount of productive land. SCIMAP is a risk-based model that has been developed for this purpose but with a focus on diffuse sediment and nutrient pollution. In this study we investigated the performance of SCIMAP in predicting microbial pollution of watercourses and assessed modelled outputs of E. coli, a common faecal indicator organism (FIO), against observed water quality information. SCIMAP was applied to two river catchments in the UK. SCIMAP uses land cover risk weightings, which are routed through the landscape based on hydrological connectivity to generate catchment scale maps of relative in-stream pollution risk. Assessment of the model's performance and derivation of optimum land cover risk weightings was achieved using a Monte-Carlo sampling approach. Performance of the SCIMAP framework for informing on FIO risk was variable with better performance in the Yealm catchment (r s =0.88; p<0.01) than the Wyre (r s =-0.36; p>0.05). Across both catchments much uncertainty was associated with the application of optimum risk weightings attributed to different land use classes. Overall, SCIMAP showed potential as a useful tool in the spatial targeting of FIO diffuse pollution management strategies; however, improvements are required to transition the existing SCIMAP framework to a robust

Novel MixSIAR fingerprint model implementation in a Mediterranean mountain catchment

NASA Astrophysics Data System (ADS)

Lizaga, Ivan; Gaspar, Leticia; Blake, William; Palazón, Leticia; Quijano, Laura; Navas, Ana

2017-04-01

Increased sediment erosion levels can lead to degraded water and food quality, reduced aquatic biodiversity, decrease reservoir capacity and restrict recreational usage but determining soil redistribution and sediment budgets in watersheds is often challenging. One of the methods for making such determinations applies sediment fingerprinting methods by using sediment properties. The fingerprinting procedure tests a range of source material tracer properties to select a subset that can discriminate between the different potential sediment sources. The present study aims to test the feasibility of geochemical and radioisotopic fingerprint properties to apportion sediment sources within the Barués catchment. For this purpose, the new MixSIAR unmixing model was implemented as statistical tool. A total of 98 soil samples from different land cover sources (Mediterranean forest, pine forest scrubland, agricultural and subsoil) were collected in the Barués catchment (23 km2). This new approach divides the catchment into six different sub-catchments to evaluate how the sediment provenance varies along the river and the percentage of its sources and not only the contribution at the end. For this purpose, target sediments were collected at the end of each sub-catchment to introduce the variation along the entire catchment. Geochemistry and radioisotopic activity were analyzed for each sample and introduced as input parameters in the model. Percentage values from the five sources were different along the different subcatchments and the variations of all of them are summarized at the final target sample located at the end of the catchment. This work represents a good approximation to the fine sediment provenance in Mediterranean agricultural catchments and has the potential to be used for water resource control and future soil management. Identifying sediment contribution from different land uses offers considerable potential to prevent environmental degradation and the

AFFTC commander Brig. Gen. Curtis Bedke experienced a Shuttle approach and landing in NASA's Shuttle Training Aircraft from STS-114 commander Eileen Collins

NASA Image and Video Library

2005-03-29

Brig. Gen. Curtis Bedke, commander of the Air Force Flight Test Center at Edwards Air Force Base, received some first-hand insight on how to fly a Space Shuttle approach and landing, courtesy of NASA astronaut and STS-114 mission commander Eileen Collins. The series of proficiency flights in NASA's modified Grumman Gulfstream-II Shuttle Training Aircraft were in preparation for the STS-114 mission with the shuttle Discovery. Although NASA's Kennedy Space Center in Florida is the primary landing site for Space Shuttle missions, flight crews also practice the shuttle's steep approach and landing at Edwards in case weather or other situations preclude a landing at the Florida site and force a diversion to Edwards AFB.

A Monte Carlo approach to the inverse problem of diffuse pollution risk in agricultural catchments

NASA Astrophysics Data System (ADS)

Milledge, D.; Lane, S. N.; Heathwaite, A. L.; Reaney, S.

2012-04-01

The hydrological and biogeochemical processes that operate in catchments influence the ecological quality of freshwater systems through delivery of fine sediment, nutrients and organic matter. As an alternative to the, often complex, reductionist models we outline a - data-driven - approach based on 'inverse modelling'. We invert SCIMAP, a parsimonious risk based model that has an explicit treatment of hydrological connectivity, and use a Bayesian approach to determine the risk that must be assigned to different land uses in a catchment in order to explain the spatial patterns of measured in-stream nutrient concentrations. First, we apply the model to a set of eleven UK catchments to show that: 1) some land use generates a consistently high or low risk of diffuse nitrate (N) and Phosphate (P) pollution; but 2) the risks associated with different land uses vary both between catchments and between P and N delivery; and 3) that the dominant sources of P and N risk in the catchment are often a function of the spatial configuration of land uses. These results suggest that on a case by case basis, inverse modelling may be used to help prioritise the focus of interventions to reduce diffuse pollution risk for freshwater ecosystems. However, a key uncertainty in this approach is the extent to which it can recover the 'true' risks associated with a land cover given error in both the input parameters and equifinality in model outcomes. We test this using a set of synthetic scenarios in which the true risks can be pre-assigned then compared with those recovered from the inverse model. We use these scenarios to identify the number of simulations and observations required to optimize recovery of the true weights, then explore the conditions under which the inverse model becomes equifinal (hampering recovery of the true weights) We find that this is strongly dependent on the covariance in land covers between subcatchments, introducing the possibility that instream sampling could

Identifying fine sediment sources to alleviate flood risk caused by fine sediments through catchment connectivity analysis

NASA Astrophysics Data System (ADS)

Twohig, Sarah; Pattison, Ian; Sander, Graham

2017-04-01

Fine sediment poses a significant threat to UK river systems in terms of vegetation, aquatic habitats and morphology. Deposition of fine sediment onto the river bed reduces channel capacity resulting in decreased volume to contain high flow events. Once the in channel problem has been identified managers are under pressure to sustainably mitigate flood risk. With climate change and land use adaptations increasing future pressures on river catchments it is important to consider the connectivity of fine sediment throughout the river catchment and its influence on channel capacity, particularly in systems experiencing long term aggradation. Fine sediment erosion is a continuing concern in the River Eye, Leicestershire. The predominately rural catchment has a history of flooding within the town of Melton Mowbray. Fine sediment from agricultural fields has been identified as a major contributor of sediment delivery into the channel. Current mitigation measures are not sustainable or successful in preventing the continuum of sediment throughout the catchment. Identifying the potential sources and connections of fine sediment would provide insight into targeted catchment management. 'Sensitive Catchment Integrated Modelling Analysis Platforms' (SCIMAP) is a tool often used by UK catchment managers to identify potential sources and routes of sediment within a catchment. SCIMAP is a risk based model that combines hydrological (rainfall) and geomorphic controls (slope, land cover) to identify the risk of fine sediment being transported from source into the channel. A desktop version of SCIMAP was run for the River Eye at a catchment scale using 5m terrain, rainfall and land cover data. A series of SCIMAP model runs were conducted changing individual parameters to determine the sensitivity of the model. Climate Change prediction data for the catchment was used to identify potential areas of future connectivity and erosion risk for catchment managers. The results have been

Study of USGS/NASA land use classification system. [compatibility of land use classification system with computer processing techniques employed for land use mapping from ERTS data

NASA Technical Reports Server (NTRS)

Spann, G. W.; Faust, N. L.

1974-01-01

It is known from several previous investigations that many categories of land-use can be mapped via computer processing of Earth Resources Technology Satellite data. The results are presented of one such experiment using the USGS/NASA land-use classification system. Douglas County, Georgia, was chosen as the test site for this project. It was chosen primarily because of its recent rapid growth and future growth potential. Results of the investigation indicate an overall land-use mapping accuracy of 67% with higher accuracies in rural areas and lower accuracies in urban areas. It is estimated, however, that 95% of the State of Georgia could be mapped by these techniques with an accuracy of 80% to 90%.

Updates of Land Surface and Air Quality Products in NASA MAIRS and NEESPI Data Portals

NASA Technical Reports Server (NTRS)

Shen, Suhung; Leptoukh, Gregory G.; Gerasimov, Irina

2010-01-01

Following successful support of the Northern Eurasia Earth Sciences Partner Initiative (NEESPI) project with NASA satellite remote sensing data, from Spring 2009 the NASA GES DISC (Goddard Earth Sciences Data and Information Services Center) has been working on collecting more satellite and model data to support the Monsoon Asia Integrated Regional Study (MAIRS) project. The established data management and service infrastructure developed for NEESPI has been used and improved for MAIRS support.Data search, subsetting, and download functions are available through a single system. A customized Giovanni system has been created for MAIRS.The Web-based on line data analysis and visualization system, Giovanni (Goddard Interactive Online Visualization ANd aNalysis Infrastructure) allows scientists to explore, quickly analyze, and download data easily without learning the original data structure and format. Giovanni MAIRS includes satellite observations from multiple sensors and model output from the NASA Global Land Data Assimilation System (GLDAS), and from the NASA atmospheric reanalysis project, MERRA. Currently, we are working on processing and integrating higher resolution land data in to Giovanni, such as vegetation index, land surface temperature, and active fire at 5km or 1km from the standard MODIS products. For data that are not archived at the GESDISC,a product metadata portal is under development to serve as a gateway for providing product level information and data access links, which include both satellite, model products and ground-based measurements information collected from MAIRS scientists.Due to the large overlap of geographic coverage and many similar scientific interests of NEESPI and MAIRS, these data and tools will serve both projects.

Catchment management and the Great Barrier Reef.

PubMed

Brodie, J; Christie, C; Devlin, M; Haynes, D; Morris, S; Ramsay, M; Waterhouse, J; Yorkston, H

2001-01-01

Pollution of coastal regions of the Great Barrier Reef is dominated by runoff from the adjacent catchment. Catchment land-use is dominated by beef grazing and cropping, largely sugarcane cultivation, with relatively minor urban development. Runoff of sediment, nutrients and pesticides is increasing and for nitrogen is now four times the natural amount discharged 150 years ago. Significant effects and potential threats are now evident on inshore reefs, seagrasses and marine animals. There is no effective legislation or processes in place to manage agricultural pollution. The Great Barrier Reef Marine Park Act does not provide effective jurisdiction on the catchment. Queensland legislation relies on voluntary codes and there is no assessment of the effectiveness of the codes. Integrated catchment management strategies, also voluntary, provide some positive outcomes but are of limited success. Pollutant loads are predicted to continue to increase and it is unlikely that current management regimes will prevent this. New mechanisms to prevent continued degradation of inshore ecosystems of the Great Barrier Reef World Heritage Area are urgently needed.

Effects of harvest on carbon and nitrogen dynamics in a Pacific Northwest forest catchment

EPA Science Inventory

We used a new ecohydrological model, Visualizing Ecosystems for Land Management Assessments (VELMA), to analyze the effects of forest harvest on catchment carbon and nitrogen dynamics. We applied the model to a 10 ha headwater catchment in the western Oregon Cascade Range where t...

Rainfall, runoff and sediment transport in a Mediterranean mountainous catchment.

PubMed

Tuset, J; Vericat, D; Batalla, R J

2016-01-01

The relation between rainfall, runoff, erosion and sediment transport is highly variable in Mediterranean catchments. Their relation can be modified by land use changes and climate oscillations that, ultimately, will control water and sediment yields. This paper analyses rainfall, runoff and sediment transport relations in a meso-scale Mediterranean mountain catchment, the Ribera Salada (NE Iberian Peninsula). A total of 73 floods recorded between November 2005 and November 2008 at the Inglabaga Sediment Transport Station (114.5 km(2)) have been analysed. Suspended sediment transport and flow discharge were measured continuously. Rainfall data was obtained by means of direct rain gauges and daily rainfall reconstructions from radar information. Results indicate that the annual sediment yield (2.3 t km(-1) y(-1) on average) and the flood-based runoff coefficients (4.1% on average) are low. The Ribera Salada presents a low geomorphological and hydrological activity compared with other Mediterranean mountain catchments. Pearson correlations between rainfall, runoff and sediment transport variables were obtained. The hydrological response of the catchment is controlled by the base flows. The magnitude of suspended sediment concentrations is largely correlated with flood magnitude, while sediment load is correlated with the amount of direct runoff. Multivariate analysis shows that total suspended load can be predicted by integrating rainfall and runoff variables. The total direct runoff is the variable with more weight in the equation. Finally, three main hydro-sedimentary phases within the hydrological year are defined in this catchment: (a) Winter, where the catchment produces only water and very little sediment; (b) Spring, where the majority of water and sediment is produced; and (c) Summer-Autumn, when little runoff is produced but significant amount of sediments is exported out of the catchment. Results show as land use and climate change may have an important

Spatially Distributed Characterization of Catchment Dynamics Using Travel-Time Distributions

NASA Astrophysics Data System (ADS)

Heße, F.; Zink, M.; Attinger, S.

2015-12-01

The description of storage and transport of both water and solved contaminants in catchments is very difficult due to the high heterogeneity of the subsurface properties that govern their fate. This heterogeneity, combined with a generally limited knowledge about the subsurface, results in high degrees of uncertainty. As a result, stochastic methods are increasingly applied, where the relevant processes are modeled as being random. Within these methods, quantities like the catchment travel or residence time of a water parcel are described using probability density functions (PDF). The derivation of these PDF's is typically done by using the water fluxes and states of the catchment. A successful application of such frameworks is therefore contingent on a good quantification of these fluxes and states across the different spatial scales. The objective of this study is to use travel times for the characterization of an ca. 1000 square kilometer, humid catchment in Central Germany. To determine the states and fluxes, we apply the mesoscale Hydrological Model mHM, a spatially distributed hydrological model to the catchment. Using detailed data of precipitation, land cover, morphology and soil type as inputs, mHM is able to determine fluxes like recharge and evapotranspiration and states like soil moisture as outputs. Using these data, we apply the above theoretical framework to our catchment. By virtue of the aforementioned properties of mHM, we are able to describe the storage and release of water with a high spatial resolution. This allows for a comprehensive description of the flow and transport dynamics taking place in the catchment. The spatial distribution of such dynamics is then compared with land cover and soil moisture maps as well as driving forces like precipitation and temperature to determine the most predictive factors. In addition, we investigate how non-local data like the age distribution of discharge flows are impacted by, and therefore allow to infer

Insights on the impact of systematic model errors on data assimilation performance in changing catchments

NASA Astrophysics Data System (ADS)

Pathiraja, S.; Anghileri, D.; Burlando, P.; Sharma, A.; Marshall, L.; Moradkhani, H.

2018-03-01

The global prevalence of rapid and extensive land use change necessitates hydrologic modelling methodologies capable of handling non-stationarity. This is particularly true in the context of Hydrologic Forecasting using Data Assimilation. Data Assimilation has been shown to dramatically improve forecast skill in hydrologic and meteorological applications, although such improvements are conditional on using bias-free observations and model simulations. A hydrologic model calibrated to a particular set of land cover conditions has the potential to produce biased simulations when the catchment is disturbed. This paper sheds new light on the impacts of bias or systematic errors in hydrologic data assimilation, in the context of forecasting in catchments with changing land surface conditions and a model calibrated to pre-change conditions. We posit that in such cases, the impact of systematic model errors on assimilation or forecast quality is dependent on the inherent prediction uncertainty that persists even in pre-change conditions. Through experiments on a range of catchments, we develop a conceptual relationship between total prediction uncertainty and the impacts of land cover changes on the hydrologic regime to demonstrate how forecast quality is affected when using state estimation Data Assimilation with no modifications to account for land cover changes. This work shows that systematic model errors as a result of changing or changed catchment conditions do not always necessitate adjustments to the modelling or assimilation methodology, for instance through re-calibration of the hydrologic model, time varying model parameters or revised offline/online bias estimation.

Microbial water pollution: a screening tool for initial catchment-scale assessment and source apportionment.

PubMed

Kay, D; Anthony, S; Crowther, J; Chambers, B J; Nicholson, F A; Chadwick, D; Stapleton, C M; Wyer, M D

2010-11-01

The European Union Water Framework Directive requires that Management Plans are developed for individual River Basin Districts. From the point of view of faecal indicator organisms (FIOs), there is a critical need for screening tools that can provide a rapid assessment of the likely FIO concentrations and fluxes within catchments under base- and high-flow conditions, and of the balance ('source apportionment') between agriculture- and sewage-derived sources. Accordingly, the present paper reports on: (1) the development of preliminary generic models, using water quality and land cover data from previous UK catchment studies for assessing FIO concentrations, fluxes and source apportionment within catchments during the summer bathing season; (2) the calibration of national land use data, against data previously used in the models; and (3) provisional FIO concentration and source-apportionment assessments for England and Wales. The models clearly highlighted the crucial importance of high-flow conditions for the flux of FIOs within catchments. At high flow, improved grassland (and associated livestock) was the key FIO source; FIO loadings derived from catchments with high proportions of improved grassland were shown to be as high as from urbanized catchments; and in many rural catchments, especially in NW and SW England and Wales, which are important areas of lowland livestock (especially dairy) farming, ≥ 40% of FIOs was assessed to be derived from agricultural sources. In contrast, under base-flow conditions, when there was little or no runoff from agricultural land, urban (i.e. sewerage-related) sources were assessed to dominate, and even in rural areas the majority of FIOs were attributed to urban sources. The results of the study demonstrate the potential of this type of approach, particularly in light of climate change and the likelihood of more high-flow events, in underpinning informed policy development and prioritization of investment. Copyright © 2009

Patterns and processes of nutrient transfers from land to water: a catchment approach to evaluate Good Agricultural Practice in Ireland

NASA Astrophysics Data System (ADS)

Mellander, P.-E.; Melland, A. R.; Shortle, G.; Wall, D.; Mechan, S.; Buckley, C.; Fealy, R.; Jordan, P.

2009-04-01

Eutrophication of fresh, transitional and coastal waters by excessive nutrient inputs is one of the most widespread water quality problems in developed countries. Sources of nutrient nitrogen (N) and phosphorus (P) can come from a multiplicity of sources and be dependent on numerous hydrological controls from catchments with both urban and agricultural landuses. Aquatic impacts are widely reported as a result of excessive nutrient transfers from land to water and include changes in ecological integrity and loss of amenity. In the European Union, the Water Framework Directive (WFD) and associated Directives are the key structures with which member states must develop national and often trans-national polices to deal with issues of water resources management. The linked Nitrates Directive is particularly concerned with integrating sustainable agriculture and good water quality objectives and is written into national polices. In Ireland this policy is the Nitrates Directive National Action Programme (NAP), Statutory Instruction 378, Good Agricultural Practise regulation, and amongst other things, sets targets and limits on the use of organic and inorganic fertilisers, soil fertility and slurry/fertiliser spreading and cultivation times. To evaluate the effectiveness of this policy, Teagasc, the Irish Agriculture and Food Development Authority, is undertaking a catchment scale audit on sources, sinks, and changes in nutrient use and export over several years. The Agricultural Catchments Programme is based on a science-stakeholder-management partnership to generate knowledge and specifically to protect water quality from nitrogen and phosphorus transfers within the constraints of the requirements of modern Irish agricultural practises. Eight catchments of 5-12 km2 have been selected for the programme to represent a range of agricultural intensities and vulnerabilities to nitrogen and phosphorus loss including catchments that are situated on permeable and impermeable

STS-79 NASA administrator Goldin greets crew after landing

NASA Technical Reports Server (NTRS)

1996-01-01

NASA Administrator Daniel Goldin (center, with box) greets STS-79 Commander William F. Readdy following the successful conclusion of Mission STS-79 with an end of mission landing at KSC's Shuttle Landing Facility. Also climbing down from the Crew Transport Vehicle (CTV) are (from left) STS-79 Mission Specialists Carl E. Walz and Jay Apt, and Pilot Terrence W. Wilcutt. To the right of Goldin are KSC Director Jay Honeycutt and Acting Associate Administrator for the Office of Life and Microgravity Sciences and Applications Dr. Arnauld Nicogossian. Goldin is holding a box of m&m candy to give to U.S. astronaut Shannon W. Lucid, who returns to Earth after a record setting six month stay aboard the Russian Space Station Mir. The candy is a gift from President Bill Clinton for Lucid. M&M Mars has been supplying m&m candy to the U.S. space program for more than a decade; the gift candies for Lucid are red, white and blue to commemorate her historic flight.

Distributed simulation of long-term hydrological processes in a medium-sized periurban catchment under changing land use and rainwater management.

NASA Astrophysics Data System (ADS)

Labbas, Mériem; Braud, Isabelle; Branger, Flora; Kralisch, Sven

2013-04-01

Growing urbanization and related anthropogenic processes have a high potential to influence hydrological process dynamics. Typical consequences are an increase of surface imperviousness and modifications of water flow paths due to artificial channels and barriers (combined and separated system, sewer overflow device, roads, ditches, etc.). Periurban catchments, at the edge of large cities, are especially affected by fast anthropogenic modifications. They usually consist of a combination of natural areas, rural areas with dispersed settlements and urban areas mostly covered by built zones and spots of natural surfaces. In the context of the European Water Framework Directive (2000) and the Floods Directive (2007), integrated and sustainable solutions are needed to reduce flooding risks and river pollution at the scale of urban conglomerations or whole catchments. Their thorough management requires models able to assess the vulnerability of the territory and to compare the impact of different rainwater management options and planning issues. To address this question, we propose a methodology based on a multi-scale distributed hydrological modelling approach. It aims at quantifying the impact of ongoing urbanization and stormwater management on the long-term hydrological cycle in medium-sized periurban watershed. This method focuses on the understanding and formalization of dominant periurban hydrological processes from small scales (few ha to few km2) to larger scales (few hundred km2). The main objectives are to 1) simulate both urban and rural hydrological processes and 2) test the effects of different long-term land use and water management scenarios. The method relies on several tools and data: a distributed hydrological model adapted to the characteristics of periurban areas, land use and land cover maps from different dates (past, present, future) and information about rainwater management collected from local authorities. For the application of the method, the

Dissolved organic nitrogen (DON) losses from nested artificially drained lowland catchments with contrasting soil types

NASA Astrophysics Data System (ADS)

Tiemeyer, Bärbel; Kahle, Petra; Lennartz, Bernd

2010-05-01

Artificial drainage is a common practice to improve moisture and aeration conditions of agricultural land. It shortens the residence time of water in the soil and may therefore contribute to the degradation of peatlands as well as to the still elevated level of diffuse pollution of surface water bodies, particularly if flow anomalies like preferential flow cause a further acceleration of water and solute fluxes. Especially in the case of nitrate, artificially drained sub-catchments are found to control the catchment-scale nitrate losses. However, it is frequently found that nitrate losses and nitrogen field balances do not match. At the same time, organic fertilizers are commonly applied and, especially in lowland catchments, organic soils have been drained for agricultural use. Thus, the question arises whether dissolved organic nitrogen (DON) forms an important component of the nitrogen losses from artificially drained catchments. However, in contrast to nitrate and even to dissolved organic carbon (DOC), this component is frequently overlooked, especially in nested catchment studies with different soil types and variable land use. Here, we will present data from a hierarchical water quantity and quality measurement programme in the federal state Mecklenburg-Vorpommern (North-Eastern Germany). The monitoring programme in the pleistocene lowland catchment comprises automatic sampling stations at a collector drain outlet (4.2 ha catchment), at a ditch draining arable land on mineral soils (179 ha), at a ditch mainly draining grassland on organic soils (85 ha) and at a brook with a small rural catchment (15.5 km²) of mixed land use and soil types. At all sampling stations, daily to weekly composite samples were taken, while the discharge and the meteorological data were recorded continuously. Water samples were analyzed for nitrate-nitrogen, ammonium-nitrogen and total nitrogen. We will compare two years: 2006/07 was a very wet year (P = 934 mm) with a high summer

Nitrogen attenuation along delivery pathways in agricultural catchments

NASA Astrophysics Data System (ADS)

McAleer, Eoin; Mellander, Per-Erik; Coxon, Catherine; Richards, Karl G.

2014-05-01

Hillslope hydrologic systems and in particular near-stream saturated zones are active sites of nitrogen (N) biogeochemical dynamics. The efficiency of N removal and the ratio of reaction products (nitrous oxide and dinitrogen) in groundwater is highly variable and depends upon aquifer hydrology, mineralogy, dissolved oxygen, energy sources and redox chemistry. There are large uncertainties in the closing of N budgets in agricultural catchments. Spatial and temporal variability in groundwater physico-chemistry, catchment hydrology and land-use gives rise to hotspots and hot moments of N attenuation. In addition the production, consumption and movement of denitrification products remains poorly understood. The focus of this study is to develop a holistic understanding of N dynamics in groundwater as it moves from the top of the hillslope to the stream. This includes saturated groundwater flow, exchange at the groundwater-surface water interface and hyporheic zone flow. This project is being undertaken in two ca. 10km2 Irish catchments, characterised by permeable soils. One catchment is dominated by arable land overlying slate bedrock and the other by grassland overlying sandstone. Multi-level monitoring wells have been installed at the upslope, midslope and bottom of each hillslope. The piezometers are screened to intercept the subsoil, weathered bedrock and competent bedrock zones. Groundwater samples for nitrate (NO3-N) nitrite (NO2-N), ammonium (NH4-N) and total nitrogen are collected on a monthly basis while dissolved gas concentrations are collected seasonally. Groundwater NO3-N profiles from monitoring data to date in both catchments differ markedly. Although the two catchments had similar 3 year mean concentrations of 6.89 mg/L (arable) and 6.24 mg/L (grassland), the grassland catchment had higher spatial and temporal variation. The arable catchment showed relatively homogenous NO3-N concentrations in all layers and zones (range: 1.2 - 12.13 mg/L, SD = 1.60 mg

Assessing metaldehyde concentrations in surface water catchments and implications for drinking water abstraction

NASA Astrophysics Data System (ADS)

Asfaw, Alemayehu; Shucksmith, James; Smith, Andrea; Cherry, Katherine

2015-04-01

Metaldehyde is an active ingredient in agricultural pesticides such as slug pellets, which are heavily applied to UK farmland during the autumn application season. There is current concern that existing drinking water treatment processes may be inadequate in reducing potentially high levels of metaldehyde in surface waters to below the UK drinking water quality regulation limit of 0.1 µg/l. In addition, current water quality monitoring methods can miss short term fluctuations in metaldehyde concentration caused by rainfall driven runoff, hampering prediction of the potential risk of exposure. Datasets describing levels, fate and transport of metaldehyde in river catchments are currently very scarce. This work presents results from an ongoing study to quantify the presence of metaldehyde in surface waters within a UK catchment used for drinking water abstraction. High resolution water quality data from auto-samplers installed in rivers are coupled with radar rainfall, catchment characteristics and land use data to i) understand which hydro-meteorological characteristics of the catchment trigger the peak migration of metaldehyde to surface waters; ii) assess the relationship between measured metaldehyde levels and catchment characteristics such as land use, topographic index, proximity to water bodies and runoff generation area; iii) describe the current risks to drinking water supply and discuss mitigation options based on modelling and real-time control of water abstraction. Identifying the correlation between catchment attributes and metaldehyde generation will help in the development of effective catchment management strategies, which can help to significantly reduce the amount of metaldehyde finding its way into river water. Furthermore, the effectiveness of current water quality monitoring strategy in accurately quantifying the generation of metaldehyde from the catchment and its ability to benefit the development of effective catchment management practices

NASA MEaSUREs Combined ASTER and MODIS Emissivity over Land (CAMEL)

NASA Astrophysics Data System (ADS)

Borbas, E. E.; Hulley, G. C.; Feltz, M.; Knuteson, R. O.; Hook, S. J.

2016-12-01

A land surface emissivity product of the NASA MEASUREs project called Combined ASTER and MODIS Emissivity over Land (CAMEL) is being made available as part of the Unified and Coherent Land Surface Temperature and Emissivity (LST&E) Earth System Data Record (ESDR). The CAMEL database has been created by merging the UW MODIS-based baseline-fit emissivity database (UWIREMIS) developed at the University of Wisconsin-Madison, and the ASTER Global Emissivity Database (ASTER GED V4) produced at JPL. This poster will introduce the beta version of the database, which is available globally for the period 2003 through 2015 at 5km in mean monthly time-steps and for 13 bands from 3.6-14.3 micron. An algorithm to create a high spectral emissivity on 417 wavenumbers is also provided for high spectral IR applications. On the poster the CAMEL database has been evaluated with the IASI Emissivity Atlas (Zhou et al, 2010) and laboratory measurements, and also through simulation of IASI BTs in the RTTOV Forward model.

Phosphorus and dissolved organic carbon export during peak flow periods in three small homogenous catchments in eastern Germany

NASA Astrophysics Data System (ADS)

Benning, R.; Schwärzel, K.; Feger, K. H.

2012-04-01

Regional climate change scenarios for Central Europe predict both an overall increase in temperature and alterations in annual precipitation regimes. For large parts of Central Europe, climate change is expected to result in an increase in winter precipitation and a decrease in summer precipitation. In addition, an increase in extreme conditions, such as heat waves, prolonged drought periods, and heavy rainfall events are predicted. This research examines the potential impacts of increased heavy rainfall events on matter export from small catchment areas, and how different vegetation cover and land management options effects these exports. In order to evaluate the export of matter from different land-use types in the Eastern Ore Mountains (Saxony, NE Germany, 50° 48'18.06" North, 13° 36'24.54" East), study sites were established in three small catchments with homogeneous land-use. These study areas are each sub-catchments of the Ammelsdorf catchment, which provides inflow to the Lehnmühle reservoir (a major water supply for the city of Dresden). Each sub catchment represents one of the three main land-use types in the catchment area of the reservoir: crops (winter oilseed rape, winter wheat), grasslands, and forests (primarily spruce). Since November 2009 the discharge from these sub catchments has been continuously measured and water quality was analyzed on a weekly basis. During peak flow events, discharge was collected using automatic water samplers, which allowed for high temporal resolution analysis of matter export during these periods to be made. During the 2010 and 2011 hydrological years, several heavy rainfall events occurred which have been evaluated. During a 110-hour long precipitation event (P = 170 mm) between 37 and 81 water samples per sub catchment were collected and analyzed. The resulting export of dissolved phosphorus (ortho-PO4-) and dissolved organic carbon (DOC) from the sub catchments during this event is provided in the results. In

Soil water dynamics of lateritic catchments as affected by forest clearing for pasture

NASA Astrophysics Data System (ADS)

Sharma, M. L.; Barron, R. J. W.; Williamson, D. R.

1987-10-01

Aspects of soil water dynamics as affected by land use changes were examined over a period of five years (1974-1979) in two groups of adjacent catchments located in 1200 mm yr -1 and 800 mm yr -1 rainfall zones near Collie, Western Australia. In the summer of 1976/1977, after three years of calibration, 100% of one high rainfall catchment, Wights, and 53% of one lower rainfall catchment, Lemon, was cleared of native eucalyptus forest and replaced with pasture. The soil water storage down to 6m was measured in-situ using a neutron probe in fifteen access tubes located at five stratified sites in each catchment. Considerable spatial variability in soil water storage was encountered within a site, between sites within a catchment, and between paired catchments; the dominant variability being between sites. Comparisons between the pre- and postclearing states within a catchment and between the cleared and uncleared control catchments were used to evaluate the effect of change in land use on soil water dynamics. Within two years of the change from forest to pasture, a significant increase in soil water storage had occurred in the profiles in both cleared catchments. Concurrently, there was a small decrease in the uncleared control catchments. The increases following clearing were greater in the higher than in the lower rainfall catchment, more pronounced in the first year than in the second year, and occurred mostly at depths greater than 2m. In Wights catchment, the increase in summer minimum soil water storage in the first and second years amounted to 220 and 58 mm respectively, whilst for Lemon catchment the increase for the first year was < 50 mm. This increased soil water storage was due to a substantially lower evapotranspiration from the shallow-rooted, seasonally active pasture which extracts water from the top 1 m or so, compared with the perennial native eucalyptus forest which extracts water from depths down to 6 m and beyond. Due to the relatively low water

Streamflow variation of forest covered catchments

NASA Astrophysics Data System (ADS)

Gribovszki, Z.; Kalicz, P.; Kucsara, M.

2003-04-01

Rainfall concentration and runoff, otherwise rainfall-runoff processes, which cause river water discharge fluctuation, is one of the basic questions of hydrology. Several social-economy demands have a strong connection with small or bigger rivers from the point of view both quantity and quality of the water. Gratification or consideration of these demands is complicated substantially that we have still poor knowledge about our stream-flow regime. Water resources mainly stem from upper watersheds. These upper watersheds are the basis of the water concentration process; therefore we have to improve our knowledge about hydrological processes coming up in these territories. In this article we present runoff regime of two small catchments on the basis of one year data. Both catchments have a similar magnitude 0.6 and 0.9 km^2. We have been analyzed in detail some hydrological elements: features of rainfall, discharge, rainfall induced flooding waves and basic discharge in rainless periods. Variances of these parameters have been analyzed in relation to catchments surface, vegetation coverage and forest management. Result data set well enforce our knowledge about small catchments hydrological processes. On the basis of these fundamentals we can plan more established the management of these lands (forest practices, civil engineering works, and usage of natural water resources).

Integrating environmental and socio-economic indicators of a linked catchment-coastal system using variable environmental intensity.

PubMed

Dymond, John R; Davie, Tim J A; Fenemor, Andrew D; Ekanayake, Jagath C; Knight, Ben R; Cole, Anthony O; de Oca Munguia, Oscar Montes; Allen, Will J; Young, Roger G; Basher, Les R; Dresser, Marc; Batstone, Chris J

2010-09-01

Can we develop land use policy that balances the conflicting views of stakeholders in a catchment while moving toward long term sustainability? Adaptive management provides a strategy for this whereby measures of catchment performance are compared against performance goals in order to progressively improve policy. However, the feedback loop of adaptive management is often slow and irreversible impacts may result before policy has been adapted. In contrast, integrated modelling of future land use policy provides rapid feedback and potentially improves the chance of avoiding unwanted collapse events. Replacing measures of catchment performance with modelled catchment performance has usually required the dynamic linking of many models, both biophysical and socio-economic-and this requires much effort in software development. As an alternative, we propose the use of variable environmental intensity (defined as the ratio of environmental impact over economic output) in a loose coupling of models to provide a sufficient level of integration while avoiding significant effort required for software development. This model construct was applied to the Motueka Catchment of New Zealand where several biophysical (riverine water quantity, sediment, E. coli faecal bacteria, trout numbers, nitrogen transport, marine productivity) models, a socio-economic (gross output, gross margin, job numbers) model, and an agent-based model were linked. An extreme set of land use scenarios (historic, present, and intensive) were applied to this modelling framework. Results suggest that the catchment is presently in a near optimal land use configuration that is unlikely to benefit from further intensification. This would quickly put stress on water quantity (at low flow) and water quality (E. coli). To date, this model evaluation is based on a theoretical test that explores the logical implications of intensification at an unlikely extreme in order to assess the implications of likely growth

Integrating Environmental and Socio-Economic Indicators of a Linked Catchment-Coastal System Using Variable Environmental Intensity

NASA Astrophysics Data System (ADS)

Dymond, John R.; Davie, Tim J. A.; Fenemor, Andrew D.; Ekanayake, Jagath C.; Knight, Ben R.; Cole, Anthony O.; de Oca Munguia, Oscar Montes; Allen, Will J.; Young, Roger G.; Basher, Les R.; Dresser, Marc; Batstone, Chris J.

2010-09-01

Can we develop land use policy that balances the conflicting views of stakeholders in a catchment while moving toward long term sustainability? Adaptive management provides a strategy for this whereby measures of catchment performance are compared against performance goals in order to progressively improve policy. However, the feedback loop of adaptive management is often slow and irreversible impacts may result before policy has been adapted. In contrast, integrated modelling of future land use policy provides rapid feedback and potentially improves the chance of avoiding unwanted collapse events. Replacing measures of catchment performance with modelled catchment performance has usually required the dynamic linking of many models, both biophysical and socio-economic—and this requires much effort in software development. As an alternative, we propose the use of variable environmental intensity (defined as the ratio of environmental impact over economic output) in a loose coupling of models to provide a sufficient level of integration while avoiding significant effort required for software development. This model construct was applied to the Motueka Catchment of New Zealand where several biophysical (riverine water quantity, sediment, E. coli faecal bacteria, trout numbers, nitrogen transport, marine productivity) models, a socio-economic (gross output, gross margin, job numbers) model, and an agent-based model were linked. An extreme set of land use scenarios (historic, present, and intensive) were applied to this modelling framework. Results suggest that the catchment is presently in a near optimal land use configuration that is unlikely to benefit from further intensification. This would quickly put stress on water quantity (at low flow) and water quality ( E. coli). To date, this model evaluation is based on a theoretical test that explores the logical implications of intensification at an unlikely extreme in order to assess the implications of likely growth

Changing trends of rainfall and sediment fluxes in the Kinta River catchment, Malaysia

NASA Astrophysics Data System (ADS)

Ismail, W. R.; Hashim, M.

2015-03-01

The Kinta River, draining an area of 2566 km2, originates in the Korbu Mountain in Perak, Malaysia, and flows through heterogeneous, mixed land uses ranging from extensive forests to mining, rubber and oil palm plantations, and urban development. A land use change analysis of the Kinta River catchment was carried out together with assessment of the long-term trend in rainfall and sediment fluxes. The Mann-Kendall test was used to examine and assess the long-term trends in rainfall and its relationship with the sediment discharge trend. The land use analysis shows that forests, water bodies and mining land declined whilst built and agricultural land use increased significantly. This has influenced the sediment flux of the catchment. However, most of the rainfall stations and river gauging stations are experiencing an increasing trends, except at Kinta river at Tg. Rambutan. Sediment flux shows a net erosion for the period from 1961 to 1969. The total annual sediment discharge in the Kinta River catchment was low with an average rate of 1,757 t/km2/year. From 1970 to 1985, the annual sediment yield rose to an average rate of 4062 t/km2/year. Afterwards, from 1986 to 1993, the total annual sediment discharge decreased to an average rate of 1,306 t/km2/year and increased back during the period 1994 to 2000 to 2109 t/km2/year. From 2001 to 2006 the average sediment flux rate declined to 865 t/km2/year. The decline was almost 80% from the 1970s. High sediment flux in the early 1970s is partly associated with reduced tin mining activities in the area. This decreasing trend in sediment delivery leaving the Kinta River catchment is expected to continue dropping in the future.

Overview of the NASA Entry, Descent and Landing Systems Analysis Exploration Feed-Forward Study

NASA Technical Reports Server (NTRS)

DwyerCianciolo, Alicia M.; Zang, Thomas A.; Sostaric, Ronald R.; McGuire, M. Kathy

2011-01-01

Technology required to land large payloads (20 to 50 mt) on Mars remains elusive. In an effort to identify the most viable investment path, NASA and others have been studying various concepts. One such study, the Entry, Descent and Landing Systems Analysis (EDLSA) Study [1] identified three potential options: the rigid aeroshell, the inflatable aeroshell and supersonic retropropulsion (SRP). In an effort to drive out additional levels of design detail, a smaller demonstrator, or exploration feed-forward (EFF), robotic mission was devised that utilized two of the three (inflatable aeroshell and SRP) high potential technologies in a configuration to demonstrate landing a two to four metric ton payload on Mars. This paper presents and overview of the maximum landed mass, inflatable aeroshell controllability and sensor suite capability assessments of the selected technologies and recommends specific technology areas for additional work.

Landscape dynamics in the Otterbach catchment (Bavarian Forest, Southern Germany)

NASA Astrophysics Data System (ADS)

Schwindt, Daniel; Scheck, Sebastian; Scholz, Emanuel; Waltl, Peter; Völkel, Jörg

2017-04-01

As part of the TUM-CZO (TU-Munich Critical Zone Observatory), the Otterbach Valley has been focus of numerous research approaches, focusing on soil carbon dynamics, hydrological processes as well as landscape dynamics. Aim of this contribution is the reconstruction of the landscape evolution of the Otterbach catchment in context with anthropogenic land use and natural process dynamics. Therefore, studies focus on alluvial and colluvial sediments which are usually regarded as correlated with anthropogenically induced erosion. Located in the western Bavarian Forest the Otterbach is a creek of 2nd stream order and runs directly into the Danube River. Geologically, most parts of the catchment are composed of granitic rocks, mylonites and saprolites. While agricultural land use is dominant in the upper and lower reaches of the Otterbach, the steep middle reaches are forested, floodplains are used as grasslands. Settlement history points out that the forest of the so-called "Thiergarten", covering large parts of the catchment, has been used invariably for forestry, makes this study site valuable for the reconstruction of anthropogenic impact on landscape evolution. Characterization of the shallow subsurface is based on the analysis of soil pits (up to 2 m depth), core samples (up to 18 m depth) and geophysical measurements (electrical resistivity tomography, seismic refraction tomography). Temporal contextualization of sediments is achieved using radiocarbon dating. As a result of illuvial processes, clay curtains are observed almost continuously up to 18 m depth within the slope sediments, suggesting a genesis during Pleistocene warm stages. Radiocarbon dating in the alluvial floodplain point to pronounced sedimentary relocation processes between around 2.400 and 1.000 BP. This emphasizes the importance of naturally caused process dynamics as population density in the surroundings of the Otterbach catchment was low during this period and the area was mostly forested

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.

SWAT-CS: Revision and testing of SWAT for Canadian Shield catchments

NASA Astrophysics Data System (ADS)

Fu, Congsheng; James, April L.; Yao, Huaxia

2014-04-01

Canadian Shield catchments are under increasing pressure from various types of development (e.g., mining and increased cottagers) and changing climate. Within the southern part of the Canadian Shield, catchments are generally characterized by shallow forested soils with high infiltration rates and low bedrock infiltration, generating little overland flow, and macropore and subsurface flow are important streamflow generation processes. Large numbers of wetlands and lakes are also key physiographic features, and snow-processes are critical to catchment modeling in this climate. We have revised the existing, publicly available SWAT (version 2009.10.1 Beta 3) to create SWAT-CS, a version representing hydrological processes dominating Canadian Shield catchments, where forest extends over Precambrian Shield bedrock. Prior to this study, very few studies applying SWAT to Canadian Shield catchments exist (we have found three). We tested SWAT-CS using the Harp Lake catchment dataset, an Ontario Ministry of Environment research station located in south-central Ontario. Simulations were evaluated against 30 years of observational data, including streamflow from six headwater sub-catchments (0.1-1.9 km2), outflow from Harp Lake (5.4 km2) and five years of weekly snow water equivalent (SWE). The best Nash-Sutcliffe efficiency (NSE) results for daily streamflow calibration, daily streamflow validation, and SWE were 0.60, 0.65, and 0.87, respectively, for sub-catchment HP4 (with detailed land use and soil data). For this range of catchment scales, land cover and soil properties were found to be transferable across sub-catchments with similar physiographic features, namely streamflow from the remaining five sub-catchments could be modeled well using sub-catchment HP4 parameterization. The Harp Lake outflow was well modeled using the existing reservoir-based target release method, generating NSEs of 0.72 and 0.67 for calibration and verification periods respectively. With

Modeling of storm runoff and pollutant wash off processes during storm event in rapidly urbanizing catchment

NASA Astrophysics Data System (ADS)

Qin, H. P.; Yu, X. Y.; Khu, S. T.

2009-04-01

Many urban catchments in developing countries are undergoing fast economic growth, population expansion and land use/cover change. Due to the mixture of agricultural/industrial/residential land use or different urbanization level as well as lack of historical monitoring data in the developing area, storm-water runoff pollution modeling is faced with challenges of considerable spatial variations and data insufficiency. Shiyan Reservoir catchment is located in the rapidly urbanizing coastal region of Southeast China. It has six sub-catchments with largely different land use patterns and urbanization levels. A simple semi-distributed model was used to simulate the storm-water runoff pollution process during storm event in the catchment. The model adopted modified IHACRES model and exponential wash-off functions to describe storm-runoff and pollutant wash-off processes, respectively, in each of six sub-catchments. Temporary hydrological and water quality monitoring sites were set at the downstream section of each sub-catchment in Feb-May 2007, spanning non-rain and rain seasons. And the model was calibrated for storm-runoff and water quality data during two typical storm events with rainfall amount of 10mm/4hr and 73mm/5hr, respectively. The results indicated that the Nash-Sutcliffe (NS) coefficients are greater than 0.65 and 0.55 respectively for storm-runoff model calibration and validation. However although NS coefficients can reach 0.7~0.9 for pollutant wash-off model calibration based on measured data in each storm event, the simulation data can not fit well with the measured data in model validation. According to field survey observation, many litters and residuals were found to distribute in disorder in some sub-catchments or their drainage systems and to instantaneously wash off into the surface water when the rainfall amount and intensity are large enough. In order to improve storm-water runoff pollution simulation in the catchment, the variations of pollutant

Predicting nutrient responses to mitigation at catchment to national scale: the UK research platform (Invited)

NASA Astrophysics Data System (ADS)

Johnes, P.

2013-12-01

Nutrient enrichment of waters from land-based and atmospheric sources presents a significant management challenge, requiring effective stakeholder engagement and policy development, properly underpinned by robust scientific evidence. The challenge is complex, raising significant questions about the specific sources, apportionment and pathways that determine nutrient enrichment and the key priorities for effective management and policy intervention. This paper presents outputs from 4 major UK research programmes: the Defra Demonstration Test Catchments programme (DTC), the Environment Agency's Catchment Sensitive Farming monitoring and evaluation programme (CSF), Natural Resources Wales Welsh Catchment Initiative (WCI) and the NERC Environmental Virtual Observatory programme (EVOp). Funded to meet this challenge, they are delivering new understanding of the rates and sources of pollutant fluxes from land to water, their impacts on ecosystem goods and services, and likely trends under future climate and land use change from field to national scale. DTC, a 12m investment by the UK Government, has set up long-term, high resolution research platforms equipped with novel telemetered sensor networks to monitor stream ecosystem responses to on-farm mitigation measures at a representative scale for catchment management. Ecosystem structural and functional responses and bulk hydrochemistry are also being monitored using standard protocols. CSF has set up long-term, enhanced monitoring in 8 priority catchments, with monthly monitoring in a further 72 English catchments and 6 Welsh priority catchments, to identify shifts in pollutant flux to waters resulting from mitigation measures in priority areas and farming sectors. CSF and WCI have contributed to >50 million of targeted farm improvements to date, representing a significant shift in farming practice. Each programme has generated detailed evidence on stream ecosystem responses to targeted mitigation. However, to provide

The NASA-Goddard Multi-Scale Modeling Framework - Land Information System: Global Land/atmosphere Interaction with Resolved Convection

NASA Technical Reports Server (NTRS)

Mohr, Karen Irene; Tao, Wei-Kuo; Chern, Jiun-Dar; Kumar, Sujay V.; Peters-Lidard, Christa D.

2013-01-01

The present generation of general circulation models (GCM) use parameterized cumulus schemes and run at hydrostatic grid resolutions. To improve the representation of cloud-scale moist processes and landeatmosphere interactions, a global, Multi-scale Modeling Framework (MMF) coupled to the Land Information System (LIS) has been developed at NASA-Goddard Space Flight Center. The MMFeLIS has three components, a finite-volume (fv) GCM (Goddard Earth Observing System Ver. 4, GEOS-4), a 2D cloud-resolving model (Goddard Cumulus Ensemble, GCE), and the LIS, representing the large-scale atmospheric circulation, cloud processes, and land surface processes, respectively. The non-hydrostatic GCE model replaces the single-column cumulus parameterization of fvGCM. The model grid is composed of an array of fvGCM gridcells each with a series of embedded GCE models. A horizontal coupling strategy, GCE4fvGCM4Coupler4LIS, offered significant computational efficiency, with the scalability and I/O capabilities of LIS permitting landeatmosphere interactions at cloud-scale. Global simulations of 2007e2008 and comparisons to observations and reanalysis products were conducted. Using two different versions of the same land surface model but the same initial conditions, divergence in regional, synoptic-scale surface pressure patterns emerged within two weeks. The sensitivity of largescale circulations to land surface model physics revealed significant functional value to using a scalable, multi-model land surface modeling system in global weather and climate prediction.

Future Proofing Water Policy and Catchment Management for a Changing Climate: A Case Study of Competing Demands and Water Scarcity in the River Thames and Catchment

NASA Astrophysics Data System (ADS)

Whitehead, P. G.; Crossman, J.; Jin, L.

2011-12-01

The River Thames Catchment is the major water supply system in Southern England and supplies all of London's water supply from either the River Lee (a tributary of the Thames) or the main river abstraction site at Teddington (see Figure 1) or from groundwater sources in London. There has been a measurable change in rainfall patterns over the past 250 years with reducing summer rainfall and, hence flows, over the past 40 years. In 1976, following 3 dry winters, the London Reservoirs were more or less empty and the river flow direction was reversed to ensure a supply of water for London. Recent climate change studies in the Thames catchments suggest an increasing threat to water supply and also damage to river water quality and ecology. In addition to a changing climate, population levels in London have risen in recent years and the catchment is increasingly vulnerable to land use change. Since the 1920s changes in land use have increased the levels of nitrogen and phosphorus in the catchment and this trend is predicted to be exacerbated as climate change reduces freshwater dilution. Also land use is predicted to change as agriculture becomes more intensive as farmers react to higher grain and food prices. At the same time rising water temperatures has exposed the river to the potential for toxic algal blooms, such as cyanobacteria. This doom and gloom story is being managed however using a range of policy instruments, led by central government and public and private organisations such as Thames Water and the Environment Agency. Measures such as new reservoirs, a water transfer scheme from Wales and water metering to reduce demand are all being actively pursued, as are land management measures to control diffuse pollution. In order to assess the effects of climate change on the Thames catchment a major modelling study has been undertaken. The Integrated Catchment Model (INCA) has been set up for the Thames to model flow, nitrogen, phosphorus and ecology. Climate

Uncertainties around the Implementation of a Clearing-Control Policy in a Unique Catchment in Northern Australia: Exploring Equity Issues and Balancing Competing Objectives

PubMed Central

Adams, Vanessa M.; Pressey, Robert L.

2014-01-01

Land use change is the most significant driver linked to global species extinctions. In Northern Australia, the landscape is still relatively intact with very low levels of clearing. However, a re-energized political discourse around creating a northern food bowl means that currently intact ecosystems in northern Australia could be under imminent threat from increased land clearing and water extraction. These impacts are likely to be concentrated in a few regions with suitable soils and water supplies. The Daly River Catchment in the Northern Territory is an important catchment for both conservation and development. Land use in the Daly catchment has been subject to clearing guidelines that are largely untested in terms of their eventual implications for the spatial configuration of conservation and development. Given the guidelines are not legislated they might also be removed or revised by subsequent Territory Governments, including the recently-elected one. We examine the uncertainties around the spatial implications of full implementation of the Daly clearing guidelines and their potential effects on equity of opportunity across land tenures and land uses. We also examine how removal of the guidelines could affect conservation in the catchment. We conclude that the guidelines are important in supporting development in the catchment while still achieving conservation goals, and we recommend ways of implementing the guidelines to make best use of available land resources for intensified production. PMID:24798486

X-38 sails to a landing at NASA Dryden Flight Research Center July 10, 2001

NASA Technical Reports Server (NTRS)

2001-01-01

The seventh free flight of an X-38 prototype for an emergency space station crew return vehicle culminated in a graceful glide to landing under the world's largest parafoil. The mission began when the X-38 was released from NASA's B-52 mother ship over Edwards Air Force Base, California, where NASA Dryden Flight Research Center is located. The July 10, 2001 flight helped researchers evaluate software and deployment of the X-38's drogue parachute and subsequent parafoil. NASA intends to create a space-worthy Crew Return Vehicle (CRV) to be docked to the International Space Station as a 'lifeboat' to enable a full seven-person station crew to evacuate in an emergency.

X-38 sails to a landing at NASA Dryden Flight Research Center July 10, 2001

NASA Image and Video Library

2001-07-10

The seventh free flight of an X-38 prototype for an emergency space station crew return vehicle culminated in a graceful glide to landing under the world's largest parafoil. The mission began when the X-38 was released from NASA's B-52 mother ship over Edwards Air Force Base, California, where NASA Dryden Flight Research Center is located. The July 10, 2001 flight helped researchers evaluate software and deployment of the X-38's drogue parachute and subsequent parafoil. NASA intends to create a space-worthy Crew Return Vehicle (CRV) to be docked to the International Space Station as a "lifeboat" to enable a full seven-person station crew to evacuate in an emergency.

Relationships between landscape pattern, wetland characteristics, and water quality in agricultural catchments.

PubMed

Moreno-Mateos, David; Mander, Ulo; Comín, Francisco A; Pedrocchi, César; Uuemaa, Evelyn

2008-01-01

Water quality in streams is dependent on landscape metrics at catchment and wetland scales. A study was undertaken to evaluate the correlation between landscape metrics, namely patch density and area, shape, heterogeneity, aggregation, connectivity, land-use ratio, and water quality variables (salinity, nutrients, sediments, alkalinity, other potential pollutants and pH) in the agricultural areas of a semiarid Mediterranean region dominated by irrigated farmlands (NE Spain). The study also aims to develop wetland construction criteria in agricultural catchments. The percentage of arable land and landscape homogeneity (low value of Simpson index) are significantly correlated with salinity (r(2) = 0.72) and NO(3)-N variables (r(2) = 0.49) at catchment scale. The number of stock farms was correlated (Spearman's corr. = 0.60; p < 0.01) with TP concentration in stream water. The relative abundance of wetlands and the aggregation of its patches influence salinity variables at wetland scale (r(2) = 0.59 for Na(+) and K(+) concentrations). The number and aggregation of wetland patches are closely correlated to the landscape complexity of catchments, measured as patch density (r(2) = 0.69), patch size (r(2) = 0.53), and landscape heterogeneity (r(2) = 0.62). These results suggest that more effective results in water quality improvement would be achieved if we acted at both catchment and wetland scales, especially reducing landscape homogeneity and creating numerous wetlands scattered throughout the catchment. A set of guidelines for planners and decision makers is provided for future agricultural developments or to improve existing ones.

Effect of catchment land use and soil type on the concentration, quality, and bacterial degradation of riverine dissolved organic matter.

PubMed

Autio, Iida; Soinne, Helena; Helin, Janne; Asmala, Eero; Hoikkala, Laura

2016-04-01

We studied the effects of catchment characteristics (soil type and land use) on the concentration and quality of dissolved organic matter (DOM) in river water and on the bacterial degradation of terrestrial DOM. The share of organic soil was the strongest predictor of high concentrations of dissolved organic carbon, nitrogen, and phosphorus (DOC, DON, and DOP, respectively), and was linked to DOM quality. Soil type was more important than land use in determining the concentration and quality of riverine DOM. On average, 5-9 % of the DOC and 45 % of the DON were degraded by the bacterial communities within 2-3 months. Simultaneously, the proportion of humic-like compounds in the DOM pool increased. Bioavailable DON accounted for approximately one-third of the total bioavailable dissolved nitrogen, and thus, terrestrial DON can markedly contribute to the coastal plankton dynamics and support the heterotrophic food web.

Visions of our Planet's Atmosphere, Land and Oceans: NASA/NOAA E-Theater 2003

NASA Technical Reports Server (NTRS)

Hasler, Fritz

2003-01-01

The NASA/NOAA Electronic Theater presents Earth science observations from space in a spectacular way. Fly in from outer space to the conference location as well as the site of the 2002 Olympic Winter Games using data from NASA satellites and the IKONOS 'Spy Satellite". See HDTV movie Destination Earth 2002 incorporating the Olympic Zooms, NBC footage of the 2002 Olympics, the shuttle, & the best NASA/NOAA Earth science visualizations. See the latest US and international global satellite weather movies including hurricanes, typhoons & "tornadoes". See the latest visualizations from NASA/NOAA and International remote sensing missions like Terra, Aqua, GOES, GMS, SeaWiFS, & Landsat. Feel the pulse of OUT planet. See how land vegetation, ocean plankton, clouds and temperatures respond to the sun & seasons. See vortexes and currents in the global oceans that bring up the nutrients to feed tiny algae and draw the fish, whales and fisherman. See the how the ocean blooms in response to these currents and El Nino/La Nina climate changes. See the city lights, fishing fleets, gas flares and bio-mass burning of the Earth at night observed by the "night-vision" DMSP satellite. The presentation will be made using the latest HDTV and video projection technology by: Dr. Fritz Hasler NASA/Goddard Space Flight Center.

Visions of our Planet's Atmosphere, Land and Oceans: NASA/NOAA E-Theater 2003

NASA Technical Reports Server (NTRS)

Hasler, Fritz

2003-01-01

The NASA/NOAA Electronic Theater presents Earth science observations from space in a spectacular way. Fly in from outer space to the conference location as well as the site of the 2002 Olympic Winter Games using data from NASA satellites and the IKONOS "Spy Satellite". See HDTV movie Destination Earth 2002 incorporating the Olympic Zooms, NBC footage of the 2002 Olympics, the shuttle, & the best NASA/NOAA Earth science visualizations. See the latest US and international global satellite weather movies including hurricanes, typhoons & "tornadoes". See the latest visualizations from NASA/NOAA and International remote sensing missions like Terra, Aqua, GOES, GMS, SeaWiFS, & Landsat. Feel the pulse of our planet. See how land vegetation, ocean plankton, clouds and temperatures respond to the sun & seasons. See vortexes and currents in the global oceans that bring up the nutrients to feed tiny algae and draw the fish, whales and fisherman. See the how the ocean blooms in response to these currents and El Nino/La Nina climate changes. See the city lights, fishing fleets, gas flares and bio-mass burning of the Earth at night observed by the "night-vision" DMSP satellite. The presentation will be made using the latest HDTV and video projection technology by: Dr. Fritz Hasler NASA/Goddard Space Flight Center

Visions of our Planet's Atmosphere, Land and Oceans: NASA/NOAA E-Theater 2003

NASA Technical Reports Server (NTRS)

Hasler, Fritz

2003-01-01

The NASA/NOAA Electronic Theater presents Earth science observations from space in a spectacular way. Fly in from outer space to the conference location as well as the site of the 2002 Olympic Winter Games using data from NASA satellites and the IKONOS "Spy Satellite". See HDTV movie Destination Earth 2002 incorporating the Olympic Zooms, NBC footage of the 2002 Olympics, the shuttle, & the best NASA/NOAA Earth science visualizations. See the latest US and international global satellite weather movies including hurricanes, typhoons & "tornadoes". See the latest visualizations from NASA/NOAA and International remote sensing missions like Terra, Aqua, GOES, GMS , SeaWiFS, & Landsat. Feel the pulse of our planet. See how land vegetation, ocean plankton, clouds and temperatures respond to the sun & seasons. See vortexes and currents in the global oceans that bring up the nutrients to feed tiny algae and draw the fish, whales and fisherman. See the how the ocean blooms in response to these currents and El Nino/La Nina climate changes. See the city lights, fishing fleets, gas flares and bio-mass burning of the Earth at night observed by the the "night-vision" DMSP satellite. The presentation will be made using the latest HDTV and video projection technology by: Dr. Fritz Hasler NASA/Goddard Space Flight Center

1st Manned Lunar Landing and 1st Robotic Mars Landing Commemorative Release: Viking 1 Landing Site in Chryse Planitia - Infrared Image

NASA Image and Video Library

2002-07-22

This NASA Mars Odyssey image of NASA Viking 1 landing site was taken to commemorate the anniversaries of NASA Apollo 11 landing on the Moon and Viking 1 landing on Mars -- July 20, 1969 and July 20, 1976, respectively.

Effects of land preparation and artificial vegetation on soil moisture variation in a loess hilly catchment of China

NASA Astrophysics Data System (ADS)

Feng, Tianjiao; Wei, Wei; Chen, Liding; Yu, Yang

2017-04-01

In the dryland regions, soil moisture is the main factor to determine vegetation growth and ecosystem restoration. Land preparation and vegetation restoration are the principal means for improving soil water content(SWC). Thus, it is important to analyze the coupling role of these two means on soil moisture. In this study, soil moisture were monitored at a semi-arid loess hilly catchment of China, during the growing season of 2014 and 2015. Four different land preparation methods (level ditches, fish-scale pits, adverse grade tablelands and level benches)and vegetation types(Prunus armeniaca, Platycladus orientalis, Platycladus orientalis and Caragana microphylla) were included in the experimental design. Our results showed that: (1)Soil moisture content differed across land preparation types, which is higher for fish-scale pits and decreased in the order of level ditches and adverse grade tablelands.(2) Rainwater harvesting capacity of fish-scale pits is greater than adverse grade tablelands. However the water holding capacity is much higher at soils prepared with the adverse grade tablelands method than the ones prepared by fish-scale pits methods. (3) When land preparation method is similar, vegetation play a key role in soil moisture variation. For example, the mean soil moisture under a Platycladus orientalis field is 26.72% higher than a Pinus tabulaeformis field, with the same land preparation methods. (4)Soil moisture in deeper soil layers is more affected by changes in the vegetation cover while soil moisture in the shallower layers is more affected by the variation in the land preparation methods. Therefore, we suggest that vegetation types such as: Platycladus orientalisor as well as soil preparation methods such as level ditch and fish-scale pit are the most appropriate vegetation cover and land preparation methods for landscape restoration in semi-arid loess hilly area. This conclusion was made based on the vegetation type and land preparation with the

The potential for land use change to reduce flood risk in mid-sized catchments in the Myjava region of Slovakia

NASA Astrophysics Data System (ADS)

Rončák, Peter; Lisovszki, Evelin; Szolgay, Ján; Hlavčová, Kamila; Kohnová, Silvia; Csoma, Rózsa; Poórová, Jana

2017-06-01

The effects of land use management practices on surface runoff are evident on a local scale, but evidence of their impact on the scale of a watershed is limited. This study focuses on an analysis of the impact of land use changes on the flood regime in the Myjava River basin, which is located in Western Slovakia. The Myjava River basin has an area of 641.32 km2 and is typified by the formation of fast runoff processes, intensive soil erosion, and muddy floods. The main factors responsible for these problems with flooding and soil erosion are the basin's location, geology, pedology, agricultural land use, and cropping practices. The GIS-based, spatially distributed WetSpa rainfall-runoff model was used to simulate mean daily discharges in the outlet of the basin as well as the individual components of the water balance. The model was calibrated based on the period between 1997 and 2012 with outstanding results (an NS coefficient of 0.702). Various components of runoff (e.g., surface, interflow and groundwater) and several elements of the hydrological balance (evapotranspiration and soil moisture) were simulated under various land use scenarios. Six land use scenarios (`crop', `grass', `forest', `slope', `elevation' and `optimal') were developed. The first three scenarios exhibited the ability of the WetSpa model to simulate runoff under changed land use conditions and enabled a better adjustment of the land use parameters of the model. Three other "more realistic" land use scenarios, which were based on the distribution of land use classes (arable land, grass and forest) regarding permissible slopes in the catchment, confirmed the possibility of reducing surface runoff and maximum discharges with applicable changes in land use and land management. These scenarios represent practical, realistic and realizable land use management solutions and they could be economically implemented to mitigate soil erosion processes and enhance the flood protection measures in the

Linking coral river runoff proxies with climate variability, hydrology and land-use in Madagascar catchments.

PubMed

Maina, Joseph; de Moel, Hans; Vermaat, Jan E; Bruggemann, J Henrich; Guillaume, Mireille M M; Grove, Craig A; Madin, Joshua S; Mertz-Kraus, Regina; Zinke, Jens

2012-10-01

Understanding the linkages between coastal watersheds and adjacent coral reefs is expected to lead to better coral reef conservation strategies. Our study aims to examine the main predictors of environmental proxies recorded in near shore corals and therefore how linked near shore reefs are to the catchment physical processes. To achieve these, we developed models to simulate hydrology of two watersheds in Madagascar. We examined relationships between environmental proxies derived from massive Porites spp. coral cores (spectral luminescence and barium/calcium ratios), and corresponding time-series (1950-2006) data of hydrology, climate, land use and human population growth. Results suggest regional differences in the main environmental drivers of reef sedimentation: on annual time-scales, precipitation, river flow and sediment load explained the variability in coral proxies of river discharge for the northeast region, while El Niño-Southern Oscillation (ENSO) and temperature (air and sea surface) were the best predictors in the southwest region. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effects of harvest on carbon and nitrogen dynamics in a Pacific Northwest forest catchment

Treesearch

Alex Abdelnour; Robert B. McKane; Marc Stieglitz; Feifei Pan; Yiwei Cheng

2013-01-01

We used a new ecohydrological model, Visualizing Ecosystems for Land Management Assessments (VELMA), to analyze the effects of forest harvest on catchment carbon and nitrogen dynamics. We applied the model to a 10 ha headwater catchment in the western Oregon Cascade Range where two major disturbance events have occurred during the past 500 years: a stand-replacing fire...

The impact of hydrologic segmentation on the Critical Zone water fluxes of headwater catchments

NASA Astrophysics Data System (ADS)

Gutierrez-Jurado, H. A.; Dominguez, M.; Guan, H.

2017-12-01

Headwater catchments are usually located on areas with complex terrain, where variability in aspect and microclimate give rise to contrasting vegetation cover and soil properties. This fine-scale variability in land surface conditions within a catchment is usually overlooked in hydrologic models, and the resulting differences in hydrologic dynamics across the slopes neglected. In this work we evaluate the impact of the differential hydrologic response, or as we define it here, "hydrologic segmentation" on the partition of water fluxes of contrasting slopes within a series of headwater catchments across a latitudinal gradient. Our aim is to investigate the effect of hydrologically segmenting the slopes of headwater catchments as a function of their unique aspect-vegetation-soils associations, on the water fluxes of the catchments and their potential consequences on the water balance at a regional scale. Using a distributed hydrologic model and data from a series of catchments with varying land cover and climatic conditions, we run a set of simulations with and without hydrologic segmentation to assess the effect of changing the architecture of the top part of the critical zone on the evaporation, transpiration, infiltration and runoff fluxes of each catchment slope. We calibrate and compare the simulation results with observations from a network of hydrologic sensors and independent field estimates of the various water fluxes. Our results suggest that hydrologic segmentation will significantly affect both the timing and partition of evapotranspiration fluxes with direct impacts on soil moisture residence times and the potential for deep infiltration and aquifer recharge.

Expanding NASA's Land, Atmosphere Near Real-Time Capability for EOS (LANCE)

NASA Technical Reports Server (NTRS)

Davies, Diane; Michael, Karen; Masuoka, Ed; Ye, Gang; Schmaltz, Jeffrey; Harrison, Sherry; Ziskin, Daniel; Durbin, Phil B; Protack, Steve; Rinsland, Pamela Livingstone;

High spatial resolution satellite observations for validation of MODIS land products: IKONOS observations acquired under the NASA scientific data purchase.

Treesearch

Jeffrey T. Morisette; Jaime E. Nickeson; Paul Davis; Yujie Wang; Yuhong Tian; Curtis E. Woodcock; Nikolay Shabanov; Matthew Hansen; Warren B. Cohen; Doug R. Oetter; Robert E. Kennedy

2003-01-01

Phase 1I of the Scientific Data Purchase (SDP) has provided NASA investigators access to data from four different satellite and airborne data sources. The Moderate Resolution Imaging Spectrometer (MODIS) land discipline team (MODLAND) sought to utilize these data in support of land product validation activities with a lbcus on tile EOS Land Validation Core Sites. These...

Combining abiotic and biotic models - Hydraulical modeling to fill the gap between catchment and hydro-dynamic models

NASA Astrophysics Data System (ADS)

Guse, B.; Sulc, D.; Schmalz, B.; Fohrer, N.

2012-04-01

The European Water Framework Directive (WFD) requires a catchment-based approach, which is assessed in the IMPACT project by combining abiotic and biotic models. The core point of IMPACT is a model chain (catchment model -> 1-D-hydraulic model -> 3-D-hydro-morphodynamic model -> biotic habitat model) with the aim to estimate the occurrence of the target species of the WFD. Firstly, the model chain is developed for the current land use and climate conditions. Secondly, land use and climate change scenarios are developed at the catchment scale. The outputs of the catchment model for the scenarios are used as input for the next models within the model chain to estimate the effect of these changes on the target species. The eco-hydrological catchment model SWAT is applied for the Treene catchment in Northern Germany and delivers discharge and water quality parameters as a spatial explicit output for each subbasin. There is no water level information given by SWAT. However, water level values are needed as lower boundary condition for the hydro-dynamic and habitat models which are applied for the 300 m candidate reference reach. In order to fill the gap between the catchment and the hydro-morphodynamic model, the 1-D hydraulic model HEC-RAS is applied for a 3 km long reach transect from the next upstream hydrological station until the upper bound of the candidate study reach. The channel geometry for HEC-RAS was estimated based on 96 cross-sections which were measured in the IMPACT project. By using available discharge and water level measurements from the hydrological station and own flow velocity measurements, the channel resistence was estimated. HEC-RAS was run with different statistical indices (mean annual drought, mean discharge, …) for steady flow conditions. The rating curve was then constructed for the target cross-section, i.e. the lower bound of the candidate study reach, to fulfill the combining with the hydro- and morphodynamic models. These statistical

NASA Looks at Land Surface Changes Following Chilean Quake

NASA Image and Video Library

2015-10-12

On Sept. 16, 2015, a magnitude 8.3 earthquake struck near the coast of central Chile along the boundary of the Nazca and South American tectonic plates. Dubbed the Illapel earthquake, the shaking lasted at least three minutes and propelled a 15-foot (4.5-meter) tsunami that washed into Coquimbo and other coastal areas. Smaller tsunami waves raced across the Pacific and showed up on the shores of Hawaii and other islands. The earthquake and tsunami caused substantial damage in several Chilean coastal towns, and at least 13 deaths have been reported. Demanding building codes and extensive disaster preparedness helped to limit the loss of life and property. The maps above, known as interferograms, show how the quake moved the ground, as observed by the Copernicus Sentinel-1A satellite (operated by the European Space Agency) and reported by ground stations to the U.S. Geological Survey. Sentinel-1A carries a synthetic aperture radar (SAR) instrument, which beams radio signals toward the ground and measures the reflections to determine the distance between the ground and the satellite. By comparing measurements made on Aug. 24 and Sept. 17, Cunren Liang, Eric Fielding, and other researchers from NASA's Jet Propulsion Laboratory were able to determine how the land surface shifted during and after the earthquake. Interferograms can be used to estimate where the fault moved deep in Earth and which areas have increased stress and higher likelihood of future earthquakes. The details can also provide important information to better understand the earthquake process. On both the close-up and the broad-view maps, the amount of land motion is represented in shades from yellow to purple. Areas where the ground shifted the most (vertically, horizontally, or both) are represented in yellow, while areas with little change are represented in purple. Circles show the location of earthquakes and aftershocks in the two days after the initial 8.3 earthquake, as reported by the USGS

Spatial and temporal dynamics of nitrate fluxes in a mesoscale catchment

NASA Astrophysics Data System (ADS)

Muller, C.; Musolff, A.; Strachauer, U.; Brauns, M.; Tarasova, L.; Merz, R.; Knoeller, K.

2017-12-01

Spatially and temporally variable and often superimposing processes like mobilization and turnover of N-species strongly affect nitrate fluxes at catchment outlets. It remains thus challenging to determine dominant nitrate sources to derive an effective river management. Here, we combine data sets from two spatially highly resolved key-date monitoring campaigns of nitrate fluxes along a mesoscale catchment in Germany with four years of monitoring data from two representative sites within the catchment. The study area is characterized by a strong land use gradient from pristine headwaters to lowland sub-catchments with intense agricultural land use and wastewater sources. Flow conditions were assessed by a hydrograph separation showing the clear dominance of base flow during both investigations. However, the absolute amounts of discharge differed significantly from each other (outlet: 1.42 m³ s-1 versus 0.43 m³ s-1). Nitrate concentration and flux in the headwater was found to be low. In contrast, nitrate loads further downstream originate from anthropogenic sources such as effluents from wastewater treatment plants (WWTP) and agricultural land use. The agricultural contribution did not vary in terms of nitrate concentration and isotopic signature between the years but in terms of flux. The contrasting amounts of discharge between the years led to a strongly increased relative wastewater contribution with decreasing discharge. This was mainly manifested in elevated δ18O-NO3- values downstream from the wastewater discharge. The four-year monitoring at two sides clearly indicates the chemostatic character of the agricultural N-source and its distinct, yet stable isotopic fingerprint. Denitrification was found to play no dominant role only for controlling nitrate loads in the river. The spatially highly resolved monitoring approach helped to accurately define hot spots of nitrate inputs into the stream while the long-term information allowed a classification of the

Hydrological regionalisation based on available hydrological information for runoff prediction at catchment scale

NASA Astrophysics Data System (ADS)

Li, Qiaoling; Li, Zhijia; Zhu, Yuelong; Deng, Yuanqian; Zhang, Ke; Yao, Cheng

2018-06-01

Regionalisation provides a way of transferring hydrological information from gauged to ungauged catchments. The past few decades has seen several kinds of regionalisation approaches for catchment classification and runoff predictions. The underlying assumption is that catchments having similar catchment properties are hydrological similar. This requires the appropriate selection of catchment properties, particularly the inclusion of observed hydrological information, to explain the similarity of hydrological behaviour. We selected observable catchments properties and flow duration curves to reflect the hydrological behaviour, and to regionalize rainfall-runoff response for runoff prediction. As a case study, we investigated 15 catchments located in the Yangtze and Yellow River under multiple hydro-climatic conditions. A clustering scheme was developed to separate the catchments into 4 homogeneous regions by employing catchment properties including hydro-climatic attributes, topographic attributes and land cover etc. We utilized daily flow duration curves as the indicator of hydrological response and interpreted hydrological similarity by root mean square errors. The combined analysis of similarity in catchment properties and hydrological response suggested that catchments in the same homogenous region were hydrological similar. A further validation was conducted by establishing a rainfall-runoff coaxial correlation diagram for each catchment. A common coaxial correlation diagram was generated for each homogenous region. The performances of most coaxial correlation diagrams met the national standard. The coaxial correlation diagram can be transferred within the homogeneous region for runoff prediction in ungauged catchments at an hourly time scale.

Customer-oriented Data Formats and Services for Global Land Data Assimilation System (GLDAS) Products at the NASA GES DISC

NASA Technical Reports Server (NTRS)

Fang, Hongliang; Beaudoing, Hiroko; Rodell, Matthew; Teng, BIll; Vollmer, Bruce

2008-01-01

The Global Land Data Assimilation System (GLDAS) is generating a series of land surface state (e.g., soil moisture and surface temperature) and flux (e.g., evaporation and sensible heat flux) products simulated by four land surface Models (CLM, Mosaic, Noah and VIC). These products are now accessible at the Hydrology Data and Information Services Center (HDISC), a component of NASA Goddard Earth Sciences Data and Information Services Center (GESDISC).

Simulating Catchment Scale Afforestation for Mitigating Flooding

NASA Astrophysics Data System (ADS)

Barnes, M. S.; Bathurst, J. C.; Quinn, P. F.; Birkinshaw, S.

2016-12-01

After the 2013-14, and the more recent 2015-16, winter floods in the UK there were calls to 'forest the uplands' as a solution to reducing flood risk across the nation. However, the role of forests as a natural flood management practice remains highly controversial, due to a distinct lack of robust evidence into its effectiveness in reducing flood risk during extreme events. This project aims to improve the understanding of the impacts of upland afforestation on flood risk at the sub-catchment and full catchment scales. This will be achieved through an integrated fieldwork and modelling approach, with the use of a series of process based hydrological models to scale up and examine the effects forestry can have on flooding. Furthermore, there is a need to analyse the extent to which land management practices, catchment system engineering and the installation of runoff attenuation features (RAFs), such as engineered log jams, in headwater catchments can attenuate flood-wave movement, and potentially reduce downstream flood risk. Additionally, the proportion of a catchment or riparian reach that would need to be forested in order to achieve a significant impact on reducing downstream flooding will be defined. The consequential impacts of a corresponding reduction in agriculturally productive farmland and the potential decline of water resource availability will also be considered in order to safeguard the UK's food security and satisfy the global demand on water resources.

Quantifying and Modelling Long Term Sediment Dynamics in Catchments in Western Europe

NASA Astrophysics Data System (ADS)

Notebaert, B.; De Brue, H.; Verstraeten, G.; Broothaerts, N.

2015-12-01

Quantification of sediment dynamics allows to get insight in driving forces and internal dynamics of the sediment cascade system. A useful tool to achieve this is the sediment budget approach, which encompasses the quantification of different sinks and sources. A Holocene time-differentiated sediment budget has been constructed for the Belgian Dijle River catchment (720 km²), based on a large set of field data. The results show how soil erosion is driven by land use changes over longer timescales. Sediment redistribution and the relative importance of the different sinks also vary over time, mainly as a result of changing land use and related landscape connectivity. However, the coarse temporal resolution typically associated with Holocene studies complicates the understanding of sub-millennial scale processes. In a second step, the field-based sediment budget was combined with a modeling approach using Watem/Sedem, a spatially distributed model that simulates soil erosion and colluvial deposition. After validation of the model calibration against the sediment budget, the model was used in a sensitivity analysis. Results confirm the overwhelming influence of human land use on both soil erosion and landscape connectivity, whereas the climatic impact is comparatively small. In addition to catchment-wide simulations, the model also served to test the relative importance of lynchets and dry valleys in different environments. Finally, the geomorphic model was used to simulate past land use, taking into account equifinality. For this purpose, a large series of hypothetical time-independent land use maps of the Dijle catchment were modeled based on a multi-objective allocation algorithm, and applied in Watem/Sedem. Modeled soil erosion and sediment deposition outcomes for each scenario were subsequently compared with the field-based record, taking into account uncertainties. As such, the model allows to evaluate and select realistic land use scenarios for the Holocene.

Climatic and Catchment-Scale Predictors of Chinese Stream Insect Richness Differ between Taxonomic Groups

PubMed Central

Tonkin, Jonathan D.; Shah, Deep Narayan; Kuemmerlen, Mathias; Li, Fengqing; Cai, Qinghua; Haase, Peter; Jähnig, Sonja C.

2015-01-01

Little work has been done on large-scale patterns of stream insect richness in China. We explored the influence of climatic and catchment-scale factors on stream insect (Ephemeroptera, Plecoptera, Trichoptera; EPT) richness across mid-latitude China. We assessed the predictive ability of climatic, catchment land cover and physical structure variables on genus richness of EPT, both individually and combined, in 80 mid-latitude Chinese streams, spanning a 3899-m altitudinal gradient. We performed analyses using boosted regression trees and explored the nature of their influence on richness patterns. The relative importance of climate, land cover, and physical factors on stream insect richness varied considerably between the three orders, and while important for Ephemeroptera and Plecoptera, latitude did not improve model fit for any of the groups. EPT richness was linked with areas comprising high forest cover, elevation and slope, large catchments and low temperatures. Ephemeroptera favoured areas with high forest cover, medium-to-large catchment sizes, high temperature seasonality, and low potential evapotranspiration. Plecoptera richness was linked with low temperature seasonality and annual mean, and high slope, elevation and warm-season rainfall. Finally, Trichoptera favoured high elevation areas, with high forest cover, and low mean annual temperature, seasonality and aridity. Our findings highlight the variable role that catchment land cover, physical properties and climatic influences have on stream insect richness. This is one of the first studies of its kind in Chinese streams, thus we set the scene for more in-depth assessments of stream insect richness across broader spatial scales in China, but stress the importance of improving data availability and consistency through time. PMID:25909190

Land use structures fish assemblages in reservoirs of the Tennessee River

USGS Publications Warehouse

Miranda, Leandro E.; Bies, J. M.; Hann, D. A.

2015-01-01

Inputs of nutrients, sediments and detritus from catchments can promote selected components of reservoir fish assemblages, while hindering others. However, investigations linking these catchment subsidies to fish assemblages have generally focussed on one or a handful of species. Considering this paucity of community-level awareness, we sought to explore the association between land use and fish assemblage composition in reservoirs. To this end, we compared fish assemblages in reservoirs of two sub-basins of the Tennessee River representing differing intensities of agricultural development, and hypothesised that fish assemblage structure indicated by species percentage composition would differ among reservoirs in the two sub-basins. Using multivariate statistical analysis, we documented inter-basin differences in land use, reservoir productivity and fish assemblages, but no differences in reservoir morphometry or water regime. Basins were separated along a gradient of forested and non-forested catchment land cover, which was directly related to total nitrogen, total phosphorous and chlorophyll-a concentrations. Considering the extensive body of knowledge linking land use to aquatic systems, it is reasonable to postulate a hierarchical model in which productivity has direct links to terrestrial inputs, and fish assemblages have direct links to both land use and productivity. We observed a shift from an invertivore-based fish assemblage in forested catchments to a detritivore-based fish assemblage in agricultural catchments that may be a widespread pattern among reservoirs and other aquatic ecosystems.

In-Situ Denitrification and N2O Emission from Natural and Semi-natural Land Use Types in two UK Catchments

NASA Astrophysics Data System (ADS)

Sgouridis, F.; Ullah, S.

2014-12-01

Whilst data and understanding of the controls of denitrification process and the subsequent emission of N2O at microbial and plot scale exist, quantification of in situ annual denitrification rates at catchment scales is scarce due to methodological constraints in measuring in situ denitrification in large temporal and spatial scales. In situ denitrification (DNT) was measured monthly (April 2013 - October 2014) in organic (peat bog, heathland, acid grassland), forest (mixed and deciduous), and grassland (improved and semi-improved) land use types in the Ribble-Wyre and Conwy River catchments in the UK. A static chamber technique according to the 15N-Gas Flux method1 was employed for quantifying the fluxes of 15N-N2 and 15N-N2O gases after labelling the soil with 98 at% K15NO3- at tracer level amounts (10% of the ambient nitrate concentration) and sampling the chamber headspace at 0, 1, 2 and 20 hour intervals. The DNT rates ranged between 0 and 2.3 mg N m-2 h-1 and were significantly influenced by land use type (p<0.05). The annual denitrification rate of organic and forest soils (4 kg N ha-1 y-1) was 3 and 6 times less than that of semi-improved (12 kg N ha-1 y-1) and improved (23 kg N ha-1 y-1) grassland soils, respectively. The N2O emission, due to denitrification, followed a similar trend with lower fluxes from organic and higher from improved grassland soils (range: 0 - 0.04 mg N m-2 h-1), whilst the N2O:N2 ratio ranged between 0.2 and 4%. The relative contribution of denitrification to net N2O flux varied temporally and across the different land use types and ranged from 0.2 to 75%. The 15N-Gas Flux method can be successfully applied in a variety of land use types for relatively high temporal and spatial resolution measurement of in situ denitrification and the simultaneous quantification of N2 and N2O fluxes due to denitrification. Therefore the ratio of N2O:N2 and also the source apportionment for N2O can be estimated more accurately. The results suggested

Catchment Water-Energy Balance Model: Development and Applications

NASA Astrophysics Data System (ADS)

Yang, D.; Yang, H.

2017-12-01

International Hydrological community has widely recognized that the catchment water-energy balance exists, which can be expressed as a general form of E/P = f(E0/P, c), where P is precipitation, E0 is potential evaporation, and c is a parameter. Many empirical/rational formulations of the catchment water-energy balance have been proposed. Several analytical solutions of the water-energy balance equation E/P = f(E0/P, c) have been derived by using dimensional analysis and mathematic reasoning and introducing additional boundary conditions. This paper will summarize the catchment water-energy balance equations and discuss their advantages and limitations. Catchment hydrology has been greatly influenced by the intensive variability in land use/cover, precipitation and air temperature due to climate change and local human activities. The water-energy balance equation, which are usually called the Budyko framework is widely used to analyze the impacts of climate and landscape changes on regional hydrology especially the annual runoff change. In order to quantify impacts of climate change and landscape change on the catchment runoff, the climate elasticity and landscape elasticity are estimated theoretically from the catchment water-energy balance equation. The elasticity of runoff has less of a dependency on the aridity index when the climate is drier (larger aridity index). The precipitation elasticity of runoff was close to 1.0 and that of potential evaporation close to 0.0 in the extreme humid climate with no relation to the landscape conditions, which implies that catchment water balance under extremely wet condition is controlled mainly by the climate condition. We establishes a relationship between the change in the landscape parameter in the catchment water-energy balance equation and vegetation change represented by fPAR, the fraction of Photosynthetically Active Radiation absorbed by vegetation. The fPAR elasticity of runoff is introduced and estimated over

Land-cover impacts on streamflow: a change-detection modelling approach that incorporates parameter uncertainty

Treesearch

Jan Seibert; Jeffrey J. McDonnell

2010-01-01

The effect of land-use or land-cover change on stream runoff dynamics is not fully understood. In many parts of the world, forest management is the major land-cover change agent. While the paired catchment approach has been the primary methodology used to quantify such effects, it is only possible for small headwater catchments where there is uniformity in...

Seasonal exports of phosphorus from intensively fertilised nested grassland catchments.

PubMed

Lewis, Ciaran; Rafique, Rashad; Foley, Nelius; Leahy, Paul; Morgan, Gerard; Albertson, John; Kumar, Sandeep; Kiely, Gerard

2013-09-01

We carried out a one year (2002) study of phosphorus (P) loss from soil to water in three nested grassland catchments with known P input in chemical fertilizer and animal liquid slurry applications. Chemical fertilizer was applied to the grasslands between March and September and animal slurry was applied over the twelve months. The annual chemical P fertilizer applications for the 17 and 211 ha catchments were 16.4 and 23.7 kg P/ha respectively and the annual slurry applications were 10.7 and 14.0 kg P/ha, respectively. The annual total phosphorus (TP) export in stream-flow was 2.61, 2.48 and 1.61 kg P/ha for the 17, 211 and 1524 ha catchments, respectively, compared with a maximum permissible (by regulation) annual export of ca. 0.35 kg P/ha. The export rate (ratio of P export to P in land applications) was 9.6% and 6.6% from the 17 and 211 ha catchments, respectively. On average, 70% of stream flow and 85% of the P export occurred during the five wet months (October to February) indicating that when precipitation is much greater than evaporation, the hydrological conditions are most favourable for P export. However the soil quality and land use history may vary the results. Particulate P made up 22%, 43% and 37% of the TP export at the 17, 211 and 1524 ha catchment areas, respectively. As the chemical fertilizer was spread during the grass growth months (March to September), it has less immediate impact on stream water quality than the slurry applications. We also show that as the catchment scale increases, the P concentrations and P export decrease, confirming dilution due to increasing rural catchment size. In the longer term, the excess P from fertilizer maintains high soil P levels, an antecedent condition favourable to P loss from soil to water. This study confirms the significant negative water quality impact of excess P applications, particularly liquid animal slurry applications in wet winter months. The findings suggest that restricted P application in

A review of sediment and nutrient concentration data from Australia for use in catchment water quality models.

PubMed

Bartley, Rebecca; Speirs, William J; Ellis, Tim W; Waters, David K

2012-01-01

Land use (and land management) change is seen as the primary factor responsible for changes in sediment and nutrient delivery to water bodies. Understanding how sediment and nutrient (or constituent) concentrations vary with land use is critical to understanding the current and future impact of land use change on aquatic ecosystems. Access to appropriate land-use based water quality data is also important for calculating reliable load estimates using water quality models. This study collated published and unpublished runoff, constituent concentration and load data for Australian catchments. Water quality data for total suspended sediments (TSS), total nitrogen (TN) and total phosphorus (TP) were collated from runoff events with a focus on catchment areas that have a single or majority of the contributing area under one land use. Where possible, information on the dissolved forms of nutrients were also collated. For each data point, information was included on the site location, land use type and condition, contributing catchment area, runoff, laboratory analyses, the number of samples collected over the hydrograph and the mean constituent concentration calculation method. A total of ∼750 entries were recorded from 514 different geographical sites covering 13 different land uses. We found that the nutrient concentrations collected using "grab" sampling (without a well defined hydrograph) were lower than for sites with gauged auto-samplers although this data set was small and no statistical analysis could be undertaken. There was no statistically significant difference (p<0.05) between data collected at plot and catchment scales for the same land use. This is most likely due to differences in land condition over-shadowing the effects of spatial scale. There was, however, a significant difference in the concentration value for constituent samples collected from sites where >90% of the catchment was represented by a single land use, compared to sites with <90% of the

Mean transit times in headwater catchments: insights from the Otway Ranges, Australia

NASA Astrophysics Data System (ADS)

Howcroft, William; Cartwright, Ian; Morgenstern, Uwe

2018-01-01

to be vulnerable to decadal changes in land use or climate. Additionally, there may be considerable delay in contaminants reaching the stream. An increase in nitrate and sulfate concentrations in several catchments at high streamflows may represent the input of contaminants through the shallow groundwater that contributes to streamflow during the wetter months. Poor correlations between 3H activities and catchment area, drainage density, land use, and average slope imply that the MTTs are not controlled by a single parameter but a variety of factors, including catchment geomorphology and the hydraulic properties of the soils and aquifers.

Modelling the effects of land cover and climate change on soil water partitioning in a boreal headwater catchment

NASA Astrophysics Data System (ADS)

Wang, Hailong; Tetzlaff, Doerthe; Soulsby, Chris

2018-03-01

Climate and land cover are two major factors affecting the water fluxes and balance across spatiotemporal scales. These two factors and their impacts on hydrology are often interlinked. The quantification and differentiation of such impacts is important for developing sustainable land and water management strategies. Here, we calibrated the well-known Hydrus-1D model in a data-rich boreal headwater catchment in Scotland to assess the role of two dominant vegetation types (shrubs vs. trees) in regulating the soil water partitioning and balance. We also applied previously established climate projections for the area and replaced shrubs with trees to imitate current land use change proposals in the region, so as to quantify the potential impacts of climate and land cover changes on soil hydrology. Under tree cover, evapotranspiration and deep percolation to recharge groundwater was about 44% and 57% of annual precipitation, whilst they were about 10% lower and 9% higher respectively under shrub cover in this humid, low energy environment. Meanwhile, tree canopies intercepted 39% of annual precipitation in comparison to 23% by shrubs. Soils with shrub cover stored more water than tree cover. Land cover change was shown to have stronger impacts than projected climate change. With a complete replacement of shrubs with trees under future climate projections at this site, evapotranspiration is expected to increase by ∼39% while percolation to decrease by 21% relative to the current level, more pronounced than the modest changes in the two components (<8%) with climate change only. The impacts would be particularly marked in warm seasons, which may result in water stress experienced by the vegetation. The findings provide an important evidence base for adaptive management strategies of future changes in low-energy humid environments, where vegetation growth is usually restricted by radiative energy and not water availability while few studies that quantify soil water

Multiple use forest management in a catchment context

Treesearch

Wayne T. Swank

1998-01-01

Over the past several decades there has been an acceleration of needs, uses, and expectations of forest lands in many countries. Indeed, foresters in the United States are faced with exciting opportunities to provide answers on complex issues of planning, policy, and science related to multiple use management. Integrated catchment management provides a powerful...

The River EdenDTC Project: A National Demonstration Test Catchment

NASA Astrophysics Data System (ADS)

Benskin, C.; Surridge, B.; Deasy, C.; Woods, C.; Rimmer, D.; Lees, E.; Owens, G.; Jonczyk, J.; Quinton, J.; Wilkinson, M.; Perks, M.; Quinn, P.; Barker, P.; Haygarth, P.; Burke, S.; Reaney, S.; Watson, N.

2012-04-01

Our environment is a complex system of interactions between natural process and anthropogenic activities that disrupt them. It is crucial to manage the balance for continued food production whilst maintaining the quality of the environment. The challenges we face include managing the impact of agricultural land use on aquatic quality and biodiversity as an integral system, rather than as separate issues. In order to do this, it is critical to understand how the different components are linked - how does land use affect our water courses and ground water, and their associated ecosystems, and how can the impact of agricultural land use on these systems be minimised? Regulating farm nutrient management through measures that minimise sources, their exposure to mobilisation, and reduce drainage pathways to water courses are all fundamental to the UK's approach to meeting the Water Framework Directive objective of achieving 'good ecological status' in all surface and groundwater bodies by 2015. The EdenDTC project is part of a 5-year national Demonstration Test Catchments (DTC) environmental scheme, aiming to understand the above issues through combining scientific research with local knowledge and experience from multiple stakeholders. The DTC project is a 5-year initiative by Defra, Welsh Assembly Government and the Environment Agency, which encompasses a research platform covering three distinct river catchments: the Eden in Cumbria; the Wensum in Norfolk; and the Avon in Hampshire. Within the EdenDTC, the impact and effects of multiple diffuse pollutants on ecosystems and sustainable food production are being studied on a river catchment scale. Three 10 km2 focus catchments, selected to represent the different farming practices and geologies observed across the Eden, have been instrumented to record the dynamics of agricultural diffuse pollution at multiple scales. Within each focus catchment, two sub-catchments were selected: one control and one mitigation, in which

Comparison of tropospheric ozone profiles measured by lidars simultaneously over land and water during the 2017 NASA OWLETS campaign

NASA Astrophysics Data System (ADS)

Gronoff, G.; Sullivan, J.; Berkoff, T.; Carrion, W.; Farris, B.

2017-12-01

The NASA Langley Mobile Ozone Lidar (LMOL) and NASA Goddard's lidar (TROPOZ) have routinely measured tropospheric ozone profiles in support of various NASA campaigns and local field studies since 2013 (e.g. DISCOVER-AQ 2014). They are both charter members of the NASA Tropospheric Lidar Network (TOLNet) and were constructed within transportable containers, allowing for observations directly within a variety of complex environments. To gain a better understanding of ozone's interactions close to the surface, both of these instruments have recently designed and optimized near field optical elements for ozone detection. One of the major difficulties for the modeling and satellite communities are the sharp transition regions, both horizontal and vertical, such as the land-water gradients in O3 near coastal/urban regions that are driven by differences in surface deposition, boundary layer height, and cloud coverage.To better understand these gradients, both lidars were deployed in the Hampton Roads / Tidewater region, in Virginia, in July-August 2017, in the context of the OWLETS (Ozone Water Land Environment Transition Study) campaign. The TROPOZ lidar was deployed above land at NASA LaRC, while the LMOL lidar was deployed on the Chesapeake Bay Bridge Tunnel third island, being de-facto an over-water lidar. The distance between the two lidars was approximately 30 km. Strong differences between the two lidars measurements were observed. Some influence of the ship traffic can be seen over water, but does not affect the observations above 300m. Overall, some important discrepancies between the modeling and the lidar observations over water were found. These results shows the importance of making more measurements over water to better constrain pollution models.

Understanding catchment scale sediment sources using geochemical tracers

NASA Astrophysics Data System (ADS)

Ferreira, Carla S. S.; Walsh, Rory P. D.; Shakesby, Richard A.; Steenhuis, Tammo S.; Ferreira, António J. D.; Coelho, Celeste O. A.

2013-04-01

It is well-established that urbanization leads to increased erosion (at least locally) as well as enhanced overland flow and streamflow peaks. Less is known about how the spatial distribution of erosion sources and scale of increases in erosion vary with the nature of urbanization in different climatic and socio-economic settings. This is important in order to prevent or reduce adverse impacts of erosion on downstream sedimentation, channel siltation and shifting, and river pollution. This paper adopts a sediment fingerprinting approach to assess the impact of partial urbanization and associated land-use change on sediment sources within a peri-urban catchment (6 km2), Ribeira dos Covões on the outskirts of the city of Coimbra in central Portugal. Urban land-use has increased from just 6% in 1958 to 30% in 2009. The urban pattern includes some well-defined urban residential centres, but also areas of discontinuous urban sprawl, including educational, health and small industrial facilities, numerous new roads and an enterprise park is under construction on the upper part of the catchment. The catchment has a wet Mediterranean climate and the lithology comprises sandstone in the west and limestone in the east. Soil depth is generally >40cm. The average slope angle is 8° (maximum 47°). Altitude ranges from 30m to 205m. A sediment fingerprinting approach was adopted to help establish the relative importance of sediment inputs from different urban areas. During September 2012 current bed-sediment samples (0-3 cm depth) were collected from 11 channel sites along the main stream and in different tributaries. At sites where bed-sediment was deeper, additional samples were taken at 3cm intervals to a maximum depth of around 42cm. In addition, overbank sediment samples (0-3cm depth) were collected at 11 locations around the catchment. All samples were oven-dried (at 38°C) and different particle size fractions (0.125-2mm, 0.063-0.125mm and <0.063mm) obtained, where the <0

Applications of NASA GSFC's Land Information System (LIS) for water resources management in Korea and East-Asia

NASA Astrophysics Data System (ADS)

Kang, D. H.; Hwang, E.; Jung, H. C.; Kim, E. J.; Peters-Lidard, C. D.; Kumar, S.; Chae, H.; Baeck, S. H.

2017-12-01

NASA has contributed to resolve global water issues by utilizing their long-term legacy of remote sensing technologies supported by a state of art software engineering. In this context, NASA Goddard Space Flight Center has developed a land surface model framework to monitor and predict water hazards such as flood and drought with the Land Information System (hereafter LIS) applied to North America and beyond it to include a global coverage. However, it is still challenging to apply the LIS to East-Asia where a rice-paddy agriculture is prevalent compared to other parts of the world, but retains a high population density in this region. Thus, this paper introduces recent efforts from the Korea Water Resources Corporation (K-water) in S. Korea to establish the LIS in East-Asia including Korea, aiming at producing surface hydrology datasets in Asia. One of the ultimate goals of this project is to manage the water hazards in Korea and to provide the water resources dataset in East-Asia by adapting the LIS with their abundantly available hydrometeorological observations to support the LIS applications. Preliminary results from initiating efforts since the beginning of 2017 between NASA and K-water are addressed in the paper to review the possible outcomes after this ongoing project to benefit both entities. Acknowledgements This research was supported by a grant (17AWMP-B079625-04) from Water Management Research Program sponsored by Ministry of Land, Infrastructure and Transport of Korean government.

Spatial patterns of stream temperatures and electric conductivity in a mesoscale catchment

NASA Astrophysics Data System (ADS)

Lieder, Ernestine; Weiler, Markus; Blume, Theresa

2017-04-01

Stream temperature and electric conductivity (EC) are both relatively easily measured and can provide valuable information on runoff generation processes and catchment storage.This study investigates the spatial variability of stream temperature and EC in a mesoscale basin. We focus on the mesoscale (sub-catchments and reach scale), and long term (seasonal / annual) stream temperature and EC patterns. Our study basin is the Attert catchment in Luxembourg (288km2), which contains multiple sub-catchments of different geology, topography and land use patterns. We installed 90 stream temperature and EC sensors at sites across the basin in summer 2015. The collected data is complemented by land use and discharge data and an extensive climate data set. Thermal sensitivity was calculated as the slope of daily air temperature-water-temperature regression line and describes the sensitivity of stream temperature to long term environmental change. Amplitude sensitivity was calculated as slope of the daily air and water temperature amplitude regression and describes the short term warming capacity of the stream. We found that groups with similar long term thermal and EC patterns are strongly related to different geological units. The sandstone reaches show the coldest temperatures and lowest annual thermal sensitivity to air temperature. The slate reaches are characterized by comparably low EC and high daily temperature amplitudes and amplitude sensitivity. Furthermore, mean annual temperatures and thermal sensitivities increase exponentially with drainage area, which can be attributed to the accumulation of heat throughout the system. On the reach scale, daily stream temperature fluctuations or sensitivities were strongly influenced by land cover distribution, stream shading and runoff volume. Daily thermal sensitivities were low for headwater streams; peaked for intermediate reaches in the middle of the catchment and then decreased again further downstream with increasing

STS_135_Landing

NASA Image and Video Library

2011-07-21

JSC2011-E-067995 (21 July 2011) --- NASA astronaut Chris Ferguson, STS-135 commander, makes a public statement as, from left, NASA Administrator Charles Bolden, along with NASA astronauts Rex Walheim, Sandy Magnus and Doug Hurley look on after the space shuttle Atlantis landed on July 21 at the Kennedy Space Center in Florida. The landing completed STS-135, the final mission of the NASA Space Shuttle Program. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

Trends and seasonality of river nutrients in agricultural catchments: 18years of weekly citizen science in France.

PubMed

Abbott, Benjamin W; Moatar, Florentina; Gauthier, Olivier; Fovet, Ophélie; Antoine, Virginie; Ragueneau, Olivier

2018-05-15

Agriculture and urbanization have disturbed three-quarters of global ice-free land surface, delivering huge amounts of nitrogen and phosphorus to freshwater ecosystems. These excess nutrients degrade habitat and threaten human food and water security at a global scale. Because most catchments are either currently subjected to, or recovering from anthropogenic nutrient loading, understanding the short- and long-term responses of river nutrients to changes in land use is essential for effective management. We analyzed a never-published, 18-year time series of anthropogenic (NO 3 - and PO 4 3- ) and naturally derived (dissolved silica) riverine nutrients in 13 catchments recovering from agricultural pollution in western France. In a citizen science initiative, high-school students sampled catchments weekly, which ranged from 26 to 1489km 2 . Nutrient concentrations decreased substantially over the period of record (19 to 50% for NO 3 - and 14 to 80% for PO 4 3- ), attributable to regional, national, and international investment and regulation, which started immediately prior to monitoring. For the majority of catchments, water quality during the summer low-flow period improved faster than during winter high-flow conditions, and annual minimum concentrations improved relatively faster than annual maximum concentrations. These patterns suggest that water-quality improvements were primarily due to elimination of discrete nutrient sources with seasonally-constant discharge (e.g. human and livestock wastewater), agreeing with available land-use and municipal records. Surprisingly, long-term nutrient decreases were not accompanied by changes in nutrient seasonality in most catchments, attributable to persistent, diffuse nutrient stocks. Despite decreases, nutrient concentrations in almost all catchments remained well above eutrophication thresholds, and because additional improvements will depend on decreasing diffuse nutrient sources, future gains may be much slower than

Modeling Land Use Change In A Tropical Environment Using Similar Hydrologic Response Units

NASA Astrophysics Data System (ADS)

Guardiola-Claramonte, M.; Troch, P.

2006-12-01

Montane mainland South East Asia comprises areas of great biological and cultural diversity. Over the last decades the region has overcome an important conversion from traditional agriculture to cash crop agriculture driven by regional and global markets. Our study aims at understanding the hydrological implications of these land use changes at the catchment scale. In 2004, networks of hydro-meteorological stations observing water and energy fluxes were installed in two 70 km2 catchments in Northern Thailand (Chiang Mai Province) and Southern China (Yunnan Province). In addition, a detailed soil surveying campaign was done at the moment of instrument installation. Land use is monitored periodically using satellite data. The Thai catchment is switching from small agricultural fields to large extensions of cash crops. The Chinese catchment is replacing the traditional forest for rubber plantations. A first comparative study based on catchments' geomorphologic characteristics, field observations and rainfall-runoff response revealed the dominant hydrologic processes in the catchments. Land use information is then translated into three different Hydrologic Response Units (HRU): rice paddies, pervious and impervious surfaces. The pervious HRU include different land uses such as different stages of forest development, rubber plantations, and agricultural fields; the impervious ones are urban areas, roads and outcrops. For each HRU a water and energy balance model is developed incorporating field observed hydrologic processes, measured field parameters, and literature-based vegetation and soil parameters to better describe the root zone, surface and subsurface flow characteristics without the need of further calibration. The HRU water and energy balance models are applied to single hillslopes and their integrated hydrologic response are compared for different land covers. Finally, the response of individual hillslopes is routed through the channel network to represent

Controls on Stormwater Runoff Quality and Quantity in Semi-arid, Urban Catchments

NASA Astrophysics Data System (ADS)

Gallo, E. L.; Brooks, P. D.; Lohse, K. A.

2009-12-01

Utilization of recharged urban runoff to complement municipal water supply has gained importance in arid regions where populations and their urban footprint continue to grow, and where water resources are scarce. However, our understanding of how runoff quantity and quality respond to urbanization in arid landscapes is largely incomplete and poses a challenge for water resources management. Here we address the question: What controls the hydrologic and hydrochemical responses of arid urban catchments? We collected water samples and stream stage data from 5 urban catchments of varied land uses (low, medium and high density residential, mixed and commercial land use) in southern Arizona during the summer rainfall seasons of 2007 and 2008. The most homogeneous catchments, as indicated by the index of landscape heterogeneity, were the least and most impervious, while the most heterogeneous sites had mid-range imperviousness. Hydrochemical responses were mixed, did not correlate with imperviousness or vegetation abundance, and were not strongly controlled by land use. Clustering analysis highlight hydrologic and sourcing controls on hydrochemistry, specifically conservative solute transport, land use specific and geologic solute sourcing and atmospheric deposition. Overall, water yields were surprisingly small (< 15%) and increased with imperviousness. Our data show that discharge responses were more sensitive to rainfall magnitude in homogeneous sites. We suggest that imperviousness and rainfall magnitude control water yields; whereas landscape heterogeneity may control a catchment’s sensitivity to generate runoff. The coupling of landscape and hydrology in controlling hydrochemistry is well illustrated by chloride (Cl), a non-reactive hydrologic tracer that was positively correlated with a large number of solutes such as ammonium, dissolved organic carbon, cadmium and zinc. We observed the highest concentrations and coefficients of variation of Cl at least and most

Analyzing the Impacts of Natural Environments on Launch and Landing Availability for NASA's Eploration Systems Development Programs

NASA Technical Reports Server (NTRS)

Altino, Karen M.; Burns, K. Lee; Barbre, Robert E.; Leahy, Frank B.

2014-01-01

NASA is developing new capabilities for human and scientific exploration beyond Earth orbit. Natural environments information is an important asset for NASA's development of the next generation space transportation system as part of the Exploration Systems Development Program, which includes the Space Launch System (SLS) and MultiPurpose Crew Vehicle (MPCV) Programs. Natural terrestrial environment conditions - such as wind, lightning and sea states - can affect vehicle safety and performance during multiple mission phases ranging from prelaunch ground processing to landing and recovery operations, including all potential abort scenarios. Space vehicles are particularly sensitive to these environments during the launch/ascent and the entry/landing phases of mission operations. The Marshall Space Flight Center (MSFC) Natural Environments Branch provides engineering design support for NASA space vehicle projects and programs by providing design engineers and mission planners with natural environments definitions as well as performing custom analyses to help characterize the impacts the natural environment may have on vehicle performance. One such analysis involves assessing the impact of natural environments to operational availability. Climatological time series of operational surface weather observations are used to calculate probabilities of meeting or exceeding various sets of hypothetical vehicle-specific parametric constraint thresholds.

Influence of urbanization pattern on stream flow of a peri-urban catchment under Mediterranean climate

NASA Astrophysics Data System (ADS)

Ferreira, Carla S. S.; Walsh, Rory P. D.; Ferreira, António J. D.; Steenhuis, Tammo S.; Coelho, Celeste A. O.

2015-04-01

The demand for better life quality and lower living costs created a great pressure on peri-urban areas, leading to significant land-use changes. The complexity of mixed land-use patterns, however, presents a challenge to understand the hydrological pathways and streamflow response involved in such changes. This study assesses the impact of a actively changing Portuguese peri-urban area on catchment hydrology. It focuses on quantifying streamflow delivery from contributing areas, of different land-use arrangement and the seasonal influence of the Mediterranean climate on stream discharge. The study focuses on Ribeira dos Covões a small (6 km2) peri-urban catchment on the outskirts of Coimbra, one of the main cities in central Portugal. Between 1958 and 2012 the urban area of the catchment expanded from 8% to 40%, mostly at the expense of agriculture (down from 48% to 4%), with woodland now accounting for the remaining 56% of the catchment area. The urban area comprises contrasting urban settings, associated with older discontinuous arrangement of buildings and urban structures and low population density (<25 inhabitants/km), and recent well-defined urban cores dominated by apartment blocks and high population density (9900 inhabitants/km). The hydrological response of the catchment has been monitored since 2007 by a flume installed at the outlet. In 2009, five rainfall gauges and eight additional water level recorders were installed upstream, to assess the hydrological response of different sub-catchments, characterized by distinct urban patterns and either limestone or sandstone lithologies. Annual runoff coefficients range between 14% and 22%. Changes in annual baseflow index (36-39% of annual rainfall) have been small with urbanization (from 34% to 40%) during the monitoring period itself. Annual runoff coefficients were lowest (14-7%) on catchments >80% woodland and highest (29% on sandstone; 18% on limestone) in the most urbanized (49-53% urban) sub-catchments

1st Manned Lunar Landing and 1st Robotic Mars Landing Commemorative Release: Viking 1 Landing Site in Chryse Planitia - Visible Image

NASA Image and Video Library

2002-07-22

NASA Viking 1 landing site is shown in this commemorative image from NASA Mars Odyssey spacecraft to celebrate the July 20, 1969 and 1976 anniversaries of NASA Apollo 11 and Viking 1 landings on the Moon and Mars, respectively.

Distinguishing spatiotemporal variability of sediment sources in small urbanized catchment as a response to urban expansion

NASA Astrophysics Data System (ADS)

Belyaev, Vladimir; Feoktistov, Artem; Huygens, Dries; Shamshurina, Eugenia; Golosov, Valentin

2014-05-01

for distinguishing contributions of different sediment sources into catchment sediment budgets on a reliable quantitative basis. In combination with microstratigraphic differentiation and dating of sediment in continuous deposition zones by 137Cs depth distribution curves and available land use records, spatial and temporal variability of sediment sources and sinks can be reconstructed for the last several decades. That is especially important for catchments which experienced profound land use changes such as transition from pristine or agriculture-dominated to urbanized environment. The example presented here describes the results of reconstruction of changing sediment source types, contributions and spatial patterns for small reservoir catchment within the city of Kursk (Sredenerusskaya Upland, Central European Russia). Combination of compound specific stable isotopes, 137Cs, sediment grain size composition, land use information for several time intervals and daily rainfall record for the Kursk meteorological station (conveniently located within the study catchment) have been employed in order to evaluate major sediment sources within the catchment, their spatial pattern and temporal changes and compare those to history of reservoir sedimentation. The reservoir is situated on the Kur River - small river which gave its name to the city itself. The dam and reservoir were constructed and put into operation in 1969, thus the beginning of its infill is located stratigraphically later than the main peak of the global 137Cs fallout. It has been found that transition from dominantly agricultural land use to urbanized conditions caused decrease of contribution of soil erosion from cultivated land and increase of that of the active gullies into reservoir sedimentation. However, it is important to note that during extreme runoff events contribution of sediment originated from soil erosion on arable land still remains dominant, even though its area within the catchment recently

NASA Land Information System (LIS) Water Availability to Support Reclamation ET Estimation

NASA Technical Reports Server (NTRS)

Toll, David; Arsenault, Kristi; Pinheiro, Ana; Peters-Lidard, Christa; Houser, Paul; Kumar, Sujay; Engman, Ted; Nigro, Joe; Triggs, Jonathan

2005-01-01

The U.S. Bureau of Reclamation identified the remote sensing of evapotranspiration (ET) as an important water flux for study and designated a test site in the Lower Colorado River basin. A consortium of groups will work together with the goal to develop more accurate and cost effective techniques using the enhanced spatial and temporal coverage afforded by remote sensing. ET is a critical water loss flux where improved estimation should lead to better management of Reclamation responsibilities. There are several areas where NASA satellite and modeling data may be useful to meet Reclamation's objectives for improved ET estimation. In this paper we outline one possible contribution to use NASA's data integration capability of the Land Information System (LIS) to provide a merger of observational (in situ and satellite) with physical process models to provide estimates of ET and other water availability outputs (e.g., runoff, soil moisture) retrospectively, in near real-time, and also providing short-term predictions.

Catchment hydrological responses to forest harvest amount and spatial pattern - 2011

EPA Science Inventory

We used an ecohydrological model, Visualizing Ecosystems for Land Management Assessments (VELMA), to analyze the effects of forest harvest location and amount on ecosystem carbon (C) and nitrogen (N) dynamics in an intensively studied headwater catchment (WS10) in western Oregon,...

Catchment hydro-biogeochemical response to forest harvest intensity and spatial pattern

EPA Science Inventory

We apply a new model, Visualizing Ecosystems for Land Management Assessment (VELMA), to Watershed 10 (WS10) in the H.J. Andrews Experimental Forest to simulate the effects of harvest intensity and spatial pattern on catchment hydrological and biogeochemical processes. Specificall...

NASA's SOFIA airborne observatory lands at Edwards AFB after being flown from Waco, Texas to NASA Dryden for systems installation, integration and flight test

NASA Image and Video Library

2007-05-31

NASA's SOFIA airborne observatory lands at Edwards AFB after being flown from Waco, Texas to NASA Dryden for systems installation, integration and flight test. NASA's Stratospheric Observatory for Infrared Astronomy, or SOFIA, arrived at NASA's Dryden Flight Research Center at Edwards Air Force Base, Calif. on May 31, 2007. The heavily modified Boeing 747SP was ferried to Dryden from Waco, Texas, where L-3 Communications Integrated Systems installed a German-built 2.5-meter infrared telescope and made other major modifications over the past several years. SOFIA is scheduled to undergo installation and integration of mission systems and a multi-phase flight test program at Dryden over the next three years that is expected to lead to a full operational capability to conduct astronomy missions in about 2010. During its expected 20-year lifetime, SOFIA will be capable of "Great Observatory" class astronomical science, providing astronomers with access to the visible, infrared and sub-millimeter spectrum with optimized performance in the mid-infrared to sub-millimeter range.

Nitrogen Concentrations and Exports in Baseflow and Stormflow from Three Small Urban Catchments in Central Florida

NASA Astrophysics Data System (ADS)

Luo, J.; Hochmuth, G.; Clark, M. W.

2014-12-01

Export of nitrogen from different watersheds across the United States is receiving increasing attention due to the impairment of water quality in receiving water bodies. Researchers have indicated that different land uses exerted a substantial influence on the water quality. Nitrogen loadings on the watershed scale are being studied in many large ecosystems, such as the Baltimore Ecosystem and Arizona Ecosystem, but only a few focuses in a smaller scale such as catchment scale. Characterization of the land use in catchment scale can better explain the observed environmental phenomena under the watershed scale and enrich the related watershed studies. Nitrogen fluxes have been studied at Lake Alice watershed in Gainesville, Florida with a focus on the rarely studied catchments such as sports fields with intensive fertilization management (SFC), urban area with reclaimed water irrigation (RWC) and urban area without irrigation (CC). The entire study started from May 2013. Discharge was monitored in the three catchments by transducers every 5 minutes. Regular biweekly grab samples in the three catchments were used to estimate the baseflow N loads, composite samples in 13 storms were collected to estimate the stormflow N loads. The results showed that in the baseflow, the average NO3-N concentration in SFC was 12.19 mg/l, which was significantly different from the urban catchments. Also there was a significant difference between the NO3-N concentrations in RWC (1.17 mg/l on average) and CC (0.60 mg/l on average). A separate log-log relationship was developed between discharge and N loads to estimate the baseflow N loads and stormflow N loads. It showed that baseflow contributed more N loads than stormflow in the three catchments in the annual N load. In conclusion, the recreational catchment received the greatest N load compared to the other catchments, so it should be the priority catchment when it comes to adopting nutrient management practices in the Lake Alice

Interactive Computing and Processing of NASA Land Surface Observations Using Google Earth Engine

NASA Technical Reports Server (NTRS)

Molthan, Andrew; Burks, Jason; Bell, Jordan

2016-01-01

Google's Earth Engine offers a "big data" approach to processing large volumes of NASA and other remote sensing products. h\\ps://earthengine.google.com/ Interfaces include a Javascript or Python-based API, useful for accessing and processing over large periods of record for Landsat and MODIS observations. Other data sets are frequently added, including weather and climate model data sets, etc. Demonstrations here focus on exploratory efforts to perform land surface change detection related to severe weather, and other disaster events.

Impact of climate change on low flow characteristics in a small catchment of central Poland

NASA Astrophysics Data System (ADS)

Banasik, K.; Kaznowska, E.

2016-12-01

The Zagozdzonka catchment (left tributary of Vistula River) is a small lowland agricultural catchment, located in central Poland, about 100 km south of Warsaw. Hydrological investigations of the Zagozdzonka River at Plachty (N51°26'43.8''; E21°27'35.6''), have been carried out by the Department of River Engineering of Warsaw University of Life Science (WULS) since 1962. The catchment area is 82.4 km2 at the Plachty river gauging station. Annual data of temperature, annual and seasonal rainfall and runoff characteristics, as well as annual N-day (1-, 2-, 3-, 7-, 14- and 30-day) low flow from the catchment of the period of 53-year (1963-2015) were analysed. Mann-Kendall test was used for trend analysis. Analysis has revealed a long term decrease in annual discharge and in all of the analysed N-day low flows from the catchment, as well as a corresponding increase in annul temperature (1.61ºC/50 years) for this area of Poland. No trend was detected for annual precipitation nor summer/winter half year precipitation. There was little land use change in the catchment but remarkable increase of crop yields from the arable land in this region of Poland in the last 50 years, due to fertilisation. So the long term decrease of annual discharge and N-day low flows is assumed to be effect of higher evapotranspiration. The decrease of water resources in summer periods may cause problems when more intensive agriculture practice is planned (and water for irrigation is needed).

NASA Cold Land Processes Experiment (CLPX 2002/03): Field measurements of snowpack properties and soil moisture

Treesearch

Kelly Elder; Don Cline; Glen E. Liston; Richard Armstrong

2009-01-01

A field measurement program was undertaken as part NASA's Cold Land Processes Experiment (CLPX). Extensive snowpack and soil measurements were taken at field sites in Colorado over four study periods during the two study years (2002 and 2003). Measurements included snow depth, density, temperature, grain type and size, surface wetness, surface roughness, and...

STS-120 landing

NASA Image and Video Library

2007-11-07

(left to right) NASA Administrator Michael Griffin, NASA Assistant Administrator for Public Affairs David Mould and NASA Space Shuttle Manager Wayne Hale watch as the space shuttle Discovery comes in for landing at NASA's Kennedy Space Center, Fla., completing the 15-day STS-120 mission to the International Space Station. Discovery landed at 1:01pm EST Wednesday after a mission that included on-orbit construction of the station with the installation of the Harmony Node 2 module and the relocation of the P6 truss. Photo Credit: 'NASA/Bill Ingalls"

The catchment based approach using catchment system engineering

NASA Astrophysics Data System (ADS)

Jonczyk, Jennine; Quinn, Paul; Barber, Nicholas; Wilkinson, Mark

2015-04-01

The catchment based approach (CaBa) has been championed as a potential mechanism for delivery of environmental directives such as the Water Framework Directive in the UK. However, since its launch in 2013, there has been only limited progress towards achieving sustainable, holistic management, with only a few of examples of good practice ( e.g. from the Tyne Rivers trust). Common issues with developing catchment plans over a national scale include limited data and resources to identify issues and source of those issues, how to systematically identify suitable locations for measures or suites of measures that will have the biggest downstream impact and how to overcome barriers for implementing solutions. Catchment System Engineering (CSE) is an interventionist approach to altering the catchment scale runoff regime through the manipulation of hydrological flow pathways throughout the catchment. A significant component of the runoff generation can be managed by targeting hydrological flow pathways at source, such as overland flow, field drain and ditch function, greatly reducing erosive soil losses. Coupled with management of farm nutrients at source, many runoff attenuation features or measures can be co-located to achieve benefits for water quality and biodiversity. A catchment, community-led mitigation measures plan using the CSE approach will be presented from a catchment in Northumberland, Northern England that demonstrate a generic framework for identification of multi-purpose features that slow, store and filter runoff at strategic locations in the landscape. Measures include within-field barriers, edge of field traps and within-ditch measures. Progress on the implementation of measures will be reported alongside potential impacts on the runoff regime at both local and catchment scale and costs.

A Catchment-Based Approach to Modeling Land Surface Processes in a GCM. Part 2; Parameter Estimation and Model Demonstration

NASA Technical Reports Server (NTRS)

Ducharne, Agnes; Koster, Randal D.; Suarez, Max J.; Stieglitz, Marc; Kumar, Praveen

2000-01-01

The viability of a new catchment-based land surface model (LSM) developed for use with general circulation models is demonstrated. First, simple empirical functions -- tractable enough for operational use in the LSM -- are established that faithfully capture the control of topography on the subgrid variability of soil moisture and the surface water budget, as predicted by theory. Next, the full LSM is evaluated offline. Using forcing and validation datasets developed for PILPS Phase 2c, the minimally calibrated model is shown to reproduce observed evaporation and runoff fluxes successfully in the Red-Arkansas River Basin. A complementary idealized study that employs the range of topographic variability seen over North America demonstrates that the simulated surface water budget does vary strongly with topography, which can, by itself, induce variations in annual evaporation as high as 20%.

STS_135_Landing

NASA Image and Video Library

2011-07-21

JSC2011-E-068007 (21 July 2011) --- Green paint marks the location where Atlantis' nose landing gear came to a stop on the runway after the space shuttle landed at the Kennedy Space Center in Florida on July 21, 2011. The landing completed STS-135, the final mission of the NASA Space Shuttle Program. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

Integrating terrestrial through aquatic processing of water, carbon and nitrogen over hot, cold and lukewarm moments in mixed land use catchments

NASA Astrophysics Data System (ADS)

Band, L. E.; Lin, L.; Duncan, J. M.

2017-12-01

A major challenge in understanding and managing freshwater volumes and quality in mixed land use catchments is the detailed heterogeneity of topography, soils, canopy, and inputs of water and biogeochemicals. The short space and time scale dynamics of sources, transport and processing of water, carbon and nitrogen in natural and built environments can have a strong influence on the timing and magnitude of watershed runoff and nutrient production, ecosystem cycling and export. Hydroclimate variability induces a functional interchange of terrestrial and aquatic environments across their transition zone with the temporal and spatial expansion and contraction of soil wetness, standing and flowing water over seasonal, diurnal and storm event time scales. Variation in sources and retention of nutrients at these scales need to be understood and represented to design optimal mitigation strategies. This paper discusses the conceptual framework used to design both simulation and measurement approaches, and explores these dynamics using an integrated terrestrial-aquatic watershed model of coupled water-carbon-nitrogen processes at resolutions necessary to resolve "hot spot/hot moment" phenomena in two well studied catchments in Long Term Ecological Research sites. The potential utility of this approach for design and assessment of urban green infrastructure and stream restoration strategies is illustrated.

Landuse legacies and small streams: Identifying relationships between historical land use and contemporary stream conditions

USGS Publications Warehouse

Maloney, K.O.; Feminella, J.W.; Mitchell, R.M.; Miller, S.A.; Mulholland, P.J.; Houser, J.N.

2008-01-01

The concept of landscape legacies has been examined extensively in terrestrial ecosystems and has led to a greater understanding of contemporary ecosystem processes. However, although stream ecosystems are tightly coupled with their catchments and, thus, probably are affected strongly by historical catchment conditions, few studies have directly examined the importance of landuse legacies on streams. We examined relationships between historical land use (1944) and contemporary (2000-2003) stream physical, chemical, and biological conditions after accounting for the influences of contemporary land use (1999) and natural landscape (catchment size) variation in 12 small streams at Fort Benning, Georgia, USA. Most stream variables showed strong relationships with contemporary land use and catchment size; however, after accounting for these factors, residual variation in many variables remained significantly related to historical land use. Residual variation in benthic particulate organic matter, diatom density, % of diatoms in Eunotia spp., fish density in runs, and whole-stream gross primary productivity correlated negatively, whereas streamwater pH correlated positively, with residual variation in fraction of disturbed land in catchments in 1944 (i.e., bare ground and unpaved road cover). Residual variation in % recovering land (i.e., early successional vegetation) in 1944 was correlated positively with residual variation in streambed instability, a macroinvertebrate biotic index, and fish richness, but correlated negatively with residual variation in most benthic macroinvertebrate metrics examined (e.g., Chironomidae and total richness, Shannon diversity). In contrast, residual variation in whole-stream respiration rates was not explained by historical land use. Our results suggest that historical land use continues to influence important physical and chemical variables in these streams, and in turn, probably influences associated biota. Beyond providing insight

The Utility of the Real-Time NASA Land Information System Data for Drought Monitoring Applications

NASA Technical Reports Server (NTRS)

White, Kristopher D.; Case, Jonathan L.

2013-01-01

Measurements of soil moisture are a crucial component for the proper monitoring of drought conditions. The large spatial variability of soil moisture complicates the problem. Unfortunately, in situ soil moisture observing networks typically consist of sparse point observations, and conventional numerical model analyses of soil moisture used to diagnose drought are of coarse spatial resolution. Decision support systems such as the U.S. Drought Monitor contain drought impact resolution on sub-county scales, which may not be supported by the existing soil moisture networks or analyses. The NASA Land Information System, which is run with 3 km grid spacing over the eastern United States, has demonstrated utility for monitoring soil moisture. Some of the more useful output fields from the Land Information System are volumetric soil moisture in the 0-10 cm and 40-100 cm layers, column-integrated relative soil moisture, and the real-time green vegetation fraction derived from MODIS (Moderate Resolution Imaging Spectroradiometer) swath data that are run within the Land Information System in place of the monthly climatological vegetation fraction. While these and other variables have primarily been used in local weather models and other operational forecasting applications at National Weather Service offices, the use of the Land Information System for drought monitoring has demonstrated utility for feedback to the Drought Monitor. Output from the Land Information System is currently being used at NWS Huntsville to assess soil moisture, and to provide input to the Drought Monitor. Since feedback to the Drought Monitor takes place on a weekly basis, weekly difference plots of column-integrated relative soil moisture are being produced by the NASA Short-term Prediction Research and Transition Center and analyzed to facilitate the process. In addition to the Drought Monitor, these data are used to assess drought conditions for monthly feedback to the Alabama Drought Monitoring

Export of dissolved organic matter in relation to land use along a European climatic gradient.

PubMed

Mattsson, Tuija; Kortelainen, Pirkko; Laubel, Anker; Evans, Dylan; Pujo-Pay, Mireille; Räike, Antti; Conan, Pascal

2009-03-01

The terrestrial export of dissolved organic matter (DOM) is associated with climate, vegetation and land use, and thus is under the influence of climatic variability and human interference with terrestrial ecosystems, their soils and hydrological cycles. We present a data-set including catchments from four areas covering the major climate and land use gradients within Europe: a forested boreal zone (Finland), a temperate agricultural area (Denmark), a wet and temperate mountain region in Wales, and a warm Mediterranean catchment draining into the Gulf of Lyon. In all study areas, DOC (dissolved organic carbon) was a major fraction of DOM, with much lower proportions of DON (dissolved organic nitrogen) and DOP (dissolved organic phosphorus). A south-north gradient with highest DOC concentrations and export in the northernmost catchments was recorded: DOC concentrations and loads were highest in Finland and lowest in France. These relationships indicate that DOC concentrations/export are controlled by several factors including wetland and forest cover, precipitation and hydrological processes. DON concentrations and loads were highest in the Danish catchments and lowest in the French catchments. In Wales and Finland, DON concentrations increased with the increasing proportion of agricultural land in the catchment, whereas in Denmark and France no such relationship was found. DOP concentrations and loads were low compared to DOC and DON. The highest DOP concentrations and loads were recorded in catchments with a high extent of agricultural land, large urban areas or a high population density, reflecting the influence of human impact on DOP loads.

Remote sensing of smoke, land, and clouds from the NASA ER-2 during SAFARI 2000

NASA Astrophysics Data System (ADS)

King, Michael D.; Platnick, Steven; Moeller, Christopher C.; Revercomb, Henry E.; Chu, D. Allen

2003-07-01

The NASA ER-2 aircraft was deployed to southern Africa between 13 August and 25 September 2000 as part of the Southern African Regional Science Initiative (SAFARI) 2000. This aircraft carried a sophisticated array of multispectral scanners, multiangle spectroradiometers, a monostatic lidar, a gas correlation radiometer, upward and downward spectral flux radiometers, and two metric mapping cameras. These observations were obtained over a 3200 × 2800 km region of savanna, woody savanna, open shrubland, and grassland ecosystems throughout southern Africa and were quite often coordinated with overflights by NASA's Terra and Landsat 7 satellites. The primary purpose of this high-altitude observing platform was to obtain independent observations of smoke, clouds, and land surfaces that could be used to check the validity of various remote sensing measurements derived by Earth-orbiting satellites. These include such things as the accuracy of the Moderate Resolution Imaging Spectroradiometer (MODIS) cloud mask for distinguishing clouds and heavy aerosol from land and ocean surfaces and Terra analyses of cloud optical and microphysical properties, aerosol properties, leaf area index, vegetation index, fire occurrence, carbon monoxide, and surface radiation budget. In addition to coordination with Terra and Landsat 7 satellites, numerous flights were conducted over surface AERONET sites, flux towers in South Africa, Botswana, and Zambia, and in situ aircraft from the University of Washington, South Africa, and the United Kingdom. As a result of this experiment, the MODIS cloud mask was shown to distinguish clouds, cloud shadows, and fires over land ecosystems of southern Africa with a high degree of accuracy. In addition, data acquired from the ER-2 show the vertical distribution and stratification of aerosol layers over the subcontinent and make the first observations of a "blue spike" spectral emission signature associated with air heated by fire advecting over a cooler

NASA's Earth Observing System (EOS): Observing the Atmosphere, Land, Oceans, and Ice from Space

NASA Technical Reports Server (NTRS)

King, Michael D.

2004-01-01

The Earth Observing System (EOS) is a space-based observing system comprised of a series of satellite sensors by which scientists can monitor the Earth, a Data and Information System (EOSDIS) enabling researchers worldwide to access the satellite data, and an interdisciplinary science research program to interpret the satellite data. During this year, the last of the first series of EOS missions, Aura, was launched. Aura is designed exclusively to conduct research on the composition, chemistry, and dynamics of the Earth's upper and lower atmosphere, employing multiple instruments on a single spacecraft. Aura is the third in a series of major Earth observing satellites to study the environment and climate change and is part of NASA's Earth Science Enterprise. The first and second missions, Terra and Aqua, are designed to study the land, oceans, atmospheric constituents (aerosols, clouds, temperature, and water vapor), and the Earth's radiation budget. The other seven EOS spacecraft include satellites to study (i) land cover & land use change, (ii) solar irradiance and solar spectral variation, (iii) ice volume, (iv) ocean processes (vector wind and sea surface topography), and (v) vertical variations of clouds, water vapor, and aerosols up to and including the stratosphere. Aura's chemistry measurements will also follow up on measurements that began with NASA's Upper Atmosphere Research Satellite and continue the record of satellite ozone data collected from the TOMS missions. In this presentation I will describe how scientists are using EOS data to examine the health of the earth's atmosphere, including atmospheric chemistry, aerosol properties, and cloud properties, with a special but not exclusive look at the latest earth observing mission, Aura.

NASA's Earth Observing System (EOS): Observing the Atmosphere, Land, Oceans, and Ice from Space

NASA Technical Reports Server (NTRS)

King, Michael D.

2005-01-01

The Earth Observing System (EOS) is a space-based observing system comprised of a series of satellite sensors by whch scientists can monitor the Earth, a Data and Information System (EOSDIS) enabling researchers worldwide to access the satellite data, and an interdisciplinary science research program to interpret the satellite data. During this year, the last of the first series of EOS missions, Aura, was launched. Aura is designed exclusively to conduct research on the composition, chemistry, and dynamics of the Earth's upper and lower atmosphere, employing multiple instruments on a single spacecraft. Aura is the third in a series of major Earth observing satellites to study the environment and climate change and is part of NASA's Earth Science Enterprise. The first and second missions, Terra and Aqua, are designed to study the land, oceans, atmospheric constituents (aerosols, clouds, temperature, and water vapor), and the Earth's radiation budget. The other seven EOS spacecraft include satellites to study (i) land cover & land use change, (ii) solar irradiance and solar spectral variation, (iii) ice volume, (iv) ocean processes (vector wind and sea surface topography), and (v) vertical variations of clouds, water vapor, and aerosols up to and including the stratosphere. Aura's chemistry measurements will also follow up on measurements that began with NASA's Upper Atmosphere Research Satellite and continue the record of satellite ozone data collected from the TOMS missions. In this presentation I will describe how scientists are using EOS data to examine the health of the earth's atmosphere, including atmospheric chemistry, aerosol properties, and cloud properties, with a special look at the latest earth observing mission, Aura.

Contribution of atmospheric nitrogen deposition to diffuse pollution in a typical hilly red soil catchment in southern China.

PubMed

Shen, Jianlin; Liu, Jieyun; Li, Yong; Li, Yuyuan; Wang, Yi; Liu, Xuejun; Wu, Jinshui

2014-09-01

Atmospheric nitrogen (N) deposition is currently high and meanwhile diffuse N pollution is also serious in China. The correlation between N deposition and riverine N export and the contribution of N deposition to riverine N export were investigated in a typical hilly red soil catchment in southern China over a two-year period. N deposition was as high as 26.1 to 55.8kgN/(ha·yr) across different land uses in the studied catchment, while the riverine N exports ranged from 7.2 to 9.6kgN/(ha·yr) in the forest sub-catchment and 27.4 to 30.3kgN/(ha·yr) in the agricultural sub-catchment. The correlations between both wet N deposition and riverine N export and precipitation were highly positive, and so were the correlations between NH4(+)-N or NO3(-)-N wet deposition and riverine NH4(+)-N or NO3(-)-N exports except for NH4(+)-N in the agricultural sub-catchment, indicating that N deposition contributed to riverine N export. The monthly export coefficients of atmospheric deposited N from land to river in the forest sub-catchment (with a mean of 14%) presented a significant positive correlation with precipitation, while the monthly contributions of atmospheric deposition to riverine N export (with a mean of 18.7% in the agricultural sub-catchment and a mean of 21.0% in the whole catchment) were significantly and negatively correlated with precipitation. The relatively high contribution of N deposition to diffuse N pollution in the catchment suggests that efforts should be done to control anthropogenic reactive N emissions to the atmosphere in hilly red soil regions in southern China. Copyright © 2014. Published by Elsevier B.V.

Defining the sources of low-flow phosphorus transfers in complex catchments.

PubMed

Arnscheidt, J; Jordan, P; Li, S; McCormick, S; McFaul, R; McGrogan, H J; Neal, M; Sims, J T

2007-08-15

Nutrient transfers from the land to rivers have the potential to cause persistent eutrophic impacts at low flows even though the transfers may constitute a minor percentage of total annual fluxes. In rural catchments, the contribution from agricultural soils during storm events can be particularly large and untangling the relative contributions from multiple sources that vary in time and space is especially problematic. In this study, the potential for domestic septic tank system pollution during low flows was investigated in 3 small catchments (3 to 5 km(2)) using an integrated series of methods. These included septic system surveys, continuous (10 min) total phosphorus (TP) monitoring at the outlet of each catchment, repeated low-flow water quality surveys in sub-catchments upstream of the catchment outlets and single day river-walk water quality surveys. A series of faecal matter and grey-water fingerprinting techniques were also employed. These included determining sterol ratios in stream sediments, monitoring the presence of proteins, E. coli and enterococci bacterial signatures and boron. The total density and density of poorly maintained septic systems mirrored the magnitude of frequent TP concentrations in the catchments although this relationship was less apparent in the nested sub-catchments. The exception was possibly related to the simple hydraulics in one particular catchment and indicated temporary effluent attenuation in the other catchments. Repeated low-flow and river-walk water quality surveys highlighted discrete areas and reaches where stepped changes in nutrient concentration occurred. Bio-chemical fingerprinting showed that between 7% and 27% of sediments were contaminated with human faecal material and correlation matrices indicated that, at least during low flows, P fractions were positively correlated with some markers of faecal and grey-water contamination.

NASA Langley's Aircraft Landing Dynamics Facility

NASA Technical Reports Server (NTRS)

Davis, Pamela A.

1993-01-01

The Aircraft Landing Dynamics Facility (ALDF) is a unique facility with the ability to test aircraft landing gear systems on actual runway surfaces at operational ground speeds and loading conditions. A brief historical overview of the original Landing Loads Track (LLT) is given, followed by a detailed description of the new ALDF systems and operational capabilities.

Terrain representation impact on periurban catchment morphological properties

NASA Astrophysics Data System (ADS)

Rodriguez, F.; Bocher, E.; Chancibault, K.

2013-04-01

SummaryModelling the hydrological behaviour of suburban catchments requires an estimation of environmental features, including land use and hydrographic networks. Suburban areas display a highly heterogeneous composition and encompass many anthropogenic elements that affect water flow paths, such as ditches, sewers, culverts and embankments. The geographical data available, either raster or vector data, may be of various origins and resolutions. Urban databases often offer very detailed data for sewer networks and 3D streets, yet the data covering rural zones may be coarser. This study is intended to highlight the sensitivity of geographical data as well as the data discretisation method used on the essential features of a periurban catchment, i.e. the catchment border and the drainage network. Three methods are implemented for this purpose. The first is the DEM (for digital elevation model) treatment method, which has traditionally been applied in the field of catchment hydrology. The second is based on urban database analysis and focuses on vector data, i.e. polygons and segments. The third method is a TIN (or triangular irregular network), which provides a consistent description of flow directions from an accurate representation of slope. It is assumed herein that the width function is representative of the catchment's hydrological response. The periurban Chézine catchment, located within the Nantes metropolitan area in western France, serves as the case study. The determination of both the main morphological features and the hydrological response of a suburban catchment varies significantly according to the discretization method employed, especially on upstream rural areas. Vector- and TIN-based methods allow representing the higher drainage density of urban areas, and consequently reveal the impact of these areas on the width function, since the DEM method fails. TINs seem to be more appropriate to take streets into account, because it allows a finer

Analyzing the Impacts of Natural Environments on Launch and Landing Availability for NASA's Exploration Systems Development Programs

NASA Technical Reports Server (NTRS)

Altino, Karen M.; Burns, K. Lee; Barbre, Robert E., Jr.; Leahy, Frank B.

2014-01-01

The National Aeronautics and Space Administration (NASA) is developing new capabilities for human and scientific exploration beyond Earth orbit. Natural environments information is an important asset for NASA's development of the next generation space transportation system as part of the Exploration Systems Development (ESD) Programs, which includes the Space Launch System (SLS) and Multi-Purpose Crew Vehicle (MPCV) Programs. Natural terrestrial environment conditions - such as wind, lightning and sea states - can affect vehicle safety and performance during multiple mission phases ranging from pre-launch ground processing to landing and recovery operations, including all potential abort scenarios. Space vehicles are particularly sensitive to these environments during the launch/ascent and the entry/landing phases of mission operations. The Marshall Space Flight Center (MSFC) Natural Environments Branch provides engineering design support for NASA space vehicle projects and programs by providing design engineers and mission planners with natural environments definitions as well as performing custom analyses to help characterize the impacts the natural environment may have on vehicle performance. One such analysis involves assessing the impact of natural environments to operational availability. Climatological time series of operational surface weather observations are used to calculate probabilities of meeting/exceeding various sets of hypothetical vehicle-specific parametric constraint thresholds. Outputs are tabulated by month and hour of day to show both seasonal and diurnal variation. This paper will discuss how climate analyses are performed by the MSFC Natural Environments Branch to support the ESD Launch Availability (LA) Technical Performance Measure (TPM), the SLS Launch Availability due to Natural Environments TPM, and several MPCV (Orion) launch and landing availability analyses - including the 2014 Orion Exploration Flight Test 1 (EFT-1) mission.

Critical level of water recharges in the catchment areas of Manna watershed Bengkulu Province Indonesia

NASA Astrophysics Data System (ADS)

Amri, Khairul; Nugraha, Loparedo; Barchia, Muhammad Faiz

2017-11-01

Land use changes in Manna watershed are caused degradation in the watershed functions. When water infiltration goes down, some water runs off flowing to Manna River cause submerged on the downstream. The aim of this study is to analyze how the Manna watershed overcoming environmentally degraded conditions. The critical level of the Manna catchment areas was determined by overlaying some digital maps based on procedure applying in the Ministry of Forestry, Republic of Indonesia (P.32/MENHUT-II/2009). Measuring the critical level of the catchment also needed natural and actual infiltrations map, and the interpretation process of the analysis used ArcGIS 10.1 software. Based on the spatial data analysis by overlaying maps of slope, soils, and rainfall, the natural infiltration rate in the Manna watershed categorized high level (44.1%). While, the critical level of the catchment areas of the Manna watershed classified in good condition cover about 64,5 % of the areas, and starting to degraded state cover about 35,5 % of the watershed areas. The environment degradation conditions indicated the land use changes in the Manna watershed could deteriorate infiltration rates. The cultivated agricultural activities neglected conservation rule could accelerate the critical catchment areas in the Manna watershed.

Comparison of estuarine sediment record with modelled rates of sediment supply from a western European catchment since 1500

NASA Astrophysics Data System (ADS)

Poirier, Clément; Poitevin, Cyril; Chaumillon, Éric

2016-09-01

Marine and estuarine sediment records reporting impacts of historical land use changes exist worldwide, but they are rarely supported by direct quantified evidence of changes in denudation rates on the related catchments. Here we implement a spatially-resolved RUSLE soil erosion model on the 10 000 km2 Charente catchment (France), supplied with realistic scenarios of land-cover and climate changes since 1500, and compare the results to a 14C-dated estuarine sediment record. Despite approximations, the model correctly predicts present-day Charente river sediment load. Back-cast modelling suggests that the Charente catchment is an interesting case where the sediment supply did not change despite increase in soil erosion resulting from 18th-century deforestation because it was mitigated by drier climate during the same period. Silt-sand alternations evidenced in the sediment record were correlated with sub-decadal rainfall variability.

Using spatial-stream-network models and long-term data to understand and predict dynamics of faecal contamination in a mixed land-use catchment.

PubMed

Neill, Aaron James; Tetzlaff, Doerthe; Strachan, Norval James Colin; Hough, Rupert Lloyd; Avery, Lisa Marie; Watson, Helen; Soulsby, Chris

2018-01-15

An 11year dataset of concentrations of E. coli at 10 spatially-distributed sites in a mixed land-use catchment in NE Scotland (52km 2 ) revealed that concentrations were not clearly associated with flow or season. The lack of a clear flow-concentration relationship may have been due to greater water fluxes from less-contaminated headwaters during high flows diluting downstream concentrations, the importance of persistent point sources of E. coli both anthropogenic and agricultural, and possibly the temporal resolution of the dataset. Point sources and year-round grazing of livestock probably obscured clear seasonality in concentrations. Multiple linear regression models identified potential for contamination by anthropogenic point sources as a significant predictor of long-term spatial patterns of low, average and high concentrations of E. coli. Neither arable nor pasture land was significant, even when accounting for hydrological connectivity with a topographic-index method. However, this may have reflected coarse-scale land-cover data inadequately representing "point sources" of agricultural contamination (e.g. direct defecation of livestock into the stream) and temporal changes in availability of E. coli from diffuse sources. Spatial-stream-network models (SSNMs) were applied in a novel context, and had value in making more robust catchment-scale predictions of concentrations of E. coli with estimates of uncertainty, and in enabling identification of potential "hot spots" of faecal contamination. Successfully managing faecal contamination of surface waters is vital for safeguarding public health. Our finding that concentrations of E. coli could not clearly be associated with flow or season may suggest that management strategies should not necessarily target only high flow events or summer when faecal contamination risk is often assumed to be greatest. Furthermore, we identified SSNMs as valuable tools for identifying possible "hot spots" of contamination which

Catchment hydrological responses to forest harvest amount and spatial pattern

Treesearch

Alex Abdelnour; Marc Stieglitz; Feifei Pan; Robert McKane

2011-01-01

Forest harvest effects on streamflow generation have been well described experimentally, but a clear understanding of process-level hydrological controls can be difficult to ascertain from data alone. We apply a new model, Visualizing Ecosystems for Land Management Assessments (VELMA), to elucidate how hillslope and catchment-scale processes control stream discharge in...

Comparing catchment hydrologic response to a regional storm using specific conductivity sensors

USGS Publications Warehouse

Inserillo, Ashley; Green, Mark B.; Shanley, James B.; Boyer, Joseph

2017-01-01

A better understanding of stormwater generation and solute sources is needed to improve the protection of aquatic ecosystems, infrastructure, and human health from large runoff events. Much of our understanding of water and solutes produced during stormflow comes from studies of individual, small headwater catchments. This study compared many different types of catchments during a single large event to help isolate landscape controls on streamwater and solute generation, including human-impacted land cover. We used a distributed network of specific electrical conductivity sensors to trace storm response during the post-tropical cyclone Sandy event of October 2012 at 29 catchments across the state of New Hampshire. A citizen science sensor network, Lotic Volunteer for Temperature, Electrical Conductivity, and Stage, provided a unique opportunity to investigate high-temporal resolution stream behavior at a broad spatial scale. Three storm response metrics were analyzed in this study: (a) fraction of new water contributing to the hydrograph; (b) presence of first flush (mobilization of solutes during the beginning of the rain event); and (c) magnitude of first flush. We compared new water and first flush to 64 predictor attributes related to land cover, soil, topography, and precipitation. The new water fraction was positively correlated with low and medium intensity development in the catchment and riparian buffers and with the precipitation from a rain event 9 days prior to Sandy. The presence of first flush was most closely related (positively) to soil organic matter. Magnitude of first flush was not strongly related to any of the catchment variables. Our results highlight the potentially important role of human landscape modification in runoff generation at multiple spatial scales and the lack of a clear role in solute flushing. Further development of regional-scale in situ sensor networks will provide better understanding of stormflow and solute generation across

Applications of high resolution rainfall radar data to quantify water temperature dynamics in urban catchments

NASA Astrophysics Data System (ADS)

Croghan, Danny; Van Loon, Anne; Bradley, Chris; Sadler, Jon; Hannnah, David

2017-04-01

Studies relating rainfall events to river water quality are frequently hindered by the lack of high resolution rainfall data. Local studies are particularly vulnerable due to the spatial variability of precipitation, whilst studies in urban environments require precipitation data at high spatial and temporal resolutions. The use of point-source data makes identifying causal effects of storms on water quality problematic and can lead to erroneous interpretations. High spatial and temporal resolution rainfall radar data offers great potential to address these issues. Here we use rainfall radar data with a 1km spatial resolution and 5 minute temporal resolution sourced from the UK Met Office Nimrod system to study the effects of storm events on water temperature (WTemp) in Birmingham, UK. 28 WTemp loggers were placed over 3 catchments on a rural-urban land use gradient to identify trends in WTemp during extreme events within urban environments. Using GIS, the catchment associated with each logger was estimated, and 5 min. rainfall totals and intensities were produced for each sub-catchment. Comparisons of rainfall radar data to meteorological stations in the same grid cell revealed the high accuracy of rainfall radar data in our catchments (<5% difference for studied months). The rainfall radar data revealed substantial differences in rainfall quantity between the three adjacent catchments. The most urban catchment generally received more rainfall, with this effect greatest in the highest intensity storms, suggesting the possibility of urban heat island effects on precipitation dynamics within the catchment. Rainfall radar data provided more accurate sub-catchment rainfall totals allowing better modelled estimates of storm flow, whilst spatial fluctuations in both discharge and WTemp can be simply related to precipitation intensity. Storm flow inputs for each sub-catchment were estimated and linked to changes in WTemp. WTemp showed substantial fluctuations (>1 �

An INCA model for pathogens in rivers and catchments: Model structure, sensitivity analysis and application to the River Thames catchment, UK.

PubMed

Whitehead, P G; Leckie, H; Rankinen, K; Butterfield, D; Futter, M N; Bussi, G

2016-12-01

Pathogens are an ongoing issue for catchment water management and quantifying their transport, loss and potential impacts at key locations, such as water abstractions for public supply and bathing sites, is an important aspect of catchment and coastal management. The Integrated Catchment Model (INCA) has been adapted to model the sources and sinks of pathogens and to capture the dominant dynamics and processes controlling pathogens in catchments. The model simulates the stores of pathogens in soils, sediments, rivers and groundwaters and can account for diffuse inputs of pathogens from agriculture, urban areas or atmospheric deposition. The model also allows for point source discharges from intensive livestock units or from sewage treatment works or any industrial input to river systems. Model equations are presented and the new pathogens model has been applied to the River Thames in order to assess total coliform (TC) responses under current and projected future land use. A Monte Carlo sensitivity analysis indicates that the input coliform estimates from agricultural sources and decay rates are the crucial parameters controlling pathogen behaviour. Whilst there are a number of uncertainties associated with the model that should be accounted for, INCA-Pathogens potentially provides a useful tool to inform policy decisions and manage pathogen loading in river systems. Copyright © 2016. Published by Elsevier B.V.

Understanding sediment sources in a peri-urban Mediterranean catchment using geochemical tracers

NASA Astrophysics Data System (ADS)

Ferreira, Carla; Walsh, Rory; Kikuchi, Ryunosuke; Blake, Will

2016-04-01

One of the main physical environmental impacts of urbanization is an increase in suspended sediment concentrations and loads, particularly in the constructional phase. Impacts in peri-urban catchments characterized by a mosaic of urban and non-urban landscape elements with varying roles in acting as sources and sinks of overland flow and slope wash have received little attention, particularly in Mediterranean environments. The present study uses a sediment 'fingerprinting' approach to determine the main sediment sources in the peri-urban Ribeira dos Covões catchment (6.2km2) in Portugal and how they change during storm events following contrasting antecedent weather. The catchment, rural until 1972, underwent discontinuous urbanization in 1973-1993, followed by an urban consolidation phase. Currently, its land-use is a complex mosaic of woodland (56%), urban (40%) and agricultural (4%) land parcels. Distinct urban patterns include some well-defined urban residential centres, but also areas of discontinuous urban sprawl. Since 2010, a major road was built and an enterprise park has been under construction, covering 1% and 5% of the catchment, respectively. The catchment has a Mediterranean climate. The geology comprises sandstone (56%), limestone (41%) and alluvial deposits (3%). Soils are generally deep (>3.0m), but shallow (<0.4m) on steeper limestone terrain. The catchment has an average slope of 9° , but includes steep slopes of up to 46° . The sediment fingerprinting methodology involved characterizing the chemical properties of sediments from individual upstream sub-catchments and comparing these to the properties of downstream transported fluvial material. Three fine bed-sediment sampling surveys were carried out after (i) a long dry period (21/09/2012), (ii) a winter storm of relatively high rainfall intensity (23.2mm day-1) (19/02/2015), and (iii) after several storms in Spring (22/04/2015). All samples were oven-dried (at 38° C) and sieved to obtain

STS-35 crew & NASA management inspect OV-102 after landing at EAFB, Calif

NASA Image and Video Library

1990-12-10

STS035-S-091 (10 Dec 1990) --- Donald R. Puddy (center), Director of Flight Crew Operations at the Johnson Space Center (JSC), joins the STS-35 crewmembers in a post-landing walk-around inspection of the Columbia at Edwards Air Force Base. Crewmembers pictured are, left to right, Vance D. Brand, John M. (Mike) Lounge, Ronald A. Parise, Guy S. Gardner and Jeffrey A. Hoffman. Obscured or out of frame are Samuel T. Durrance and Robert A. R. Parker. Dr. William B. Lenoir, NASA Associate Administrator for Space Flight, is at far left background.

Influence of hydroclimatic variations on solute concentration dynamics in nested subtropical catchments with heterogeneous landscapes.

PubMed

Piazza, Gustavo Antonio; Dupas, Rémi; Gascuel-Odoux, Chantal; Grimaldi, Catherine; Pinheiro, Adilson; Kaufmann, Vander

2018-04-20

Despite global efforts to monitor water quality in catchments worldwide, tropical and subtropical zones still lack data to study the influence of human activities and climate variations on solute dynamics. In this study, we monitored ten solutes every two weeks for six years (2010-2015) in three nested catchments (2 to30 km 2 ), which contained heterogeneous landscapes composed of forests and agricultural land, and one small neighboring forested catchment (0.4 km 2 ). Data analysis revealed that i) rainfall, discharge and solute concentrations displayed no clear seasonal patterns, unlike many catchments of the temperate zone; ii) solute concentrations in the agricultural area were higher than those in the forested area, but both areas displayed similar temporal patterns due to a common hydroclimatic driver; iii) all four catchments displayed a chemostatic export regime for most of the solutes, similar to catchments of the temperate zone; and iv) a positive correlation was observed between anion concentrations and ENSO (El Niño-Southern Oscillation) index. ENSO appeared to influence both hydroclimatic and anion dynamics in these subtropical catchments. Copyright © 2018 Elsevier B.V. All rights reserved.

Crop structure in a gully catchment and the development of a loess gully (Lublin Upland, E Poland)

NASA Astrophysics Data System (ADS)

Mędrek, Karolina; Rodzik, Jan

2015-04-01

The study was conducted in a loess gully catchment with an area of 1.23 km2 and height differences of less than 50 m (213-165 m above sea level), located in Kolonia Celejów in the Nałęczów Plateau. This is one of mesoregions of Lublin Upland. In the investigated catchment, loess cover with a thickness of 10-20 m, accumulated during the Vistulian Glaciation, is dissected by a gully system with a depth of 5-15 m and total length of 7.5 km. The gully system is forested in 30% of its area. Until recently, the remaining part of the catchment under agricultural use has been dominated by conventional farming of cereals, potatoes, and sugar beets. Today, 15% of the non-forested area of the catchment is occupied by housing premises, dirt roads, and fallow land, and 45% by orchards with maintained turf, including berry plantations. This type of land management contributes to the retention of precipitation, and protects the soil from flushing. Approximately 20% of the agricultural land is occupied by conventional crops (cereals and root crops), protecting the soil to a moderate degree. Water runoff in the area does not occur every year. Approximately 20% of the agricultural land is currently occupied by cruciferous vegetables (broccoli and cauliflower), decorative shrubs, and orchards without turf in the first 2 years of use. Water and soil runoff from these crops occurs even several times per year. The majority of the material is retained in the lower part of the field, and the water flows into the gully. The crops in the fields adjacent to the ravine have a direct impact on the development of the gully. If the field is located on a raised headland, the flowing water dissects the edge of the gully, and the eroded material is accumulated on the gully bottom. If the field is located in a valley above the gullyhead, the flowing water dissects the bottom of the gully, and the eroded material is discharged outside the catchment.

Runoff Response to Rainfall in Small Catchments Burned by the 2015 Valley Fire

NASA Astrophysics Data System (ADS)

Wagenbrenner, J. W.; Coe, D. B. R.; Lindsay, D.

2016-12-01

Burned areas often produce runoff volumes and peak flows much larger than unburned forests. However, very few studies demonstrate the effect of burn severity on runoff responses, and post-fire data are especially sparse in California. We measured the effects of different degrees of burn severity on rainfall-runoff responses in six small catchments (0.15-0.65 ha) in the Northern Coast Ranges. Weirs and tipping bucket rain gages were installed after the 2015 Valley Fire and prior to any substantial rainfall. In the first wet season (Nov 2015-May 2016), one runoff event was recorded in the catchment with the lowest burn severity (42% bare soil), while 13 runoff events occurred in the catchment with the highest burn severity (68% bare soil). Preliminary results indicate the thirty minute maximum rainfall intensity that generated runoff ranged from 27 mm hr-1 in the lowest severity catchment to only 8.6 mm hr-1 in the highest severity catchment. Peak flow rates for the most intense event (27 mm hr-1), a two-year, 30-min storm, were 1.1 m3 s-1 km-2 in the lowest severity catchment and 17 m3 s-1 km-2 in the highest severity catchment. Longer duration, moderate intensity rain events produced runoff in the highest severity catchments but not the lowest severity catchments. These results are on the high end of the range of post-fire peak flow rates reported in the western US and provide an idea of potential post-fire flood potential to land and emergency management agencies.

Assessing catchment connectivity using hysteretic loops

NASA Astrophysics Data System (ADS)

Keesstra, Saskia; Masselink, Rens; Goni, Mikel; Campo, Miguel Angel; Gimenez, Rafael; Casali, Javier; Seeger, Manuel

2015-04-01

Sediment connectivity is a concept which can explain the origin, pathways and sinks of sediments within landscapes. This information is valuable for land managers to be able to take appropriate action at the correct place. Hysteresis between sediment and water discharge can give important information about the sources , pathways and conditions of sediment that arrives at the outlet of a catchment. "Hysteresis" happens when the sediment concentration associated with a certain flow rate is different depending on the direction in which the analysis is performed -towards the increase or towards the diminution of the flow. This phenomenon to some extent reflects the way in which the runoff generation processes are conjugated with those of the production and transport of sediments, hence the usefulness of hysteresis as a diagnostic hydrological parameter. However, the complexity of the phenomena and factors which determine hysteresis make its interpretation uncertain or, at the very least, problematic. Many types of hysteretic loops have been described as well as the cause for the shape of the loop, mainly describing the origin of the sediments. In this study, several measures to objectively classify hysteretic loops in an automated way were developed. These were consecutively used to classify several hundreds of loops from several agricultural catchments in Northern Spain. The data set for this study comes from four experimental watersheds in Navarre (Spain), owned and maintained by the Government of Navarre. These experimental watersheds have been monitored and studied since 1996 (La Tejería and Latxaga) and 2001 (Oskotz "principal", Op, and Oskotz "woodland", Ow). La Tejería and Latxaga watersheds, located in the Central Western part of Navarre, are roughly similar to each other regarding size (approximately 200 ha), geology (marls and sandstones), soils (fine texture topsoil), climate (humid sub Mediterranean) and land use (80-90% cultivated with winter grain crops

A multi-scale modelling procedure to quantify hydrological impacts of upland land management

NASA Astrophysics Data System (ADS)

Wheater, H. S.; Jackson, B.; Bulygina, N.; Ballard, C.; McIntyre, N.; Marshall, M.; Frogbrook, Z.; Solloway, I.; Reynolds, B.

2008-12-01

Recent UK floods have focused attention on the effects of agricultural intensification on flood risk. However, quantification of these effects raises important methodological issues. Catchment-scale data have proved inadequate to support analysis of impacts of land management change, due to climate variability, uncertainty in input and output data, spatial heterogeneity in land use and lack of data to quantify historical changes in management practices. Manipulation experiments to quantify the impacts of land management change have necessarily been limited and small scale, and in the UK mainly focused on the lowlands and arable agriculture. There is a need to develop methods to extrapolate from small scale observations to predict catchment-scale response, and to quantify impacts for upland areas. With assistance from a cooperative of Welsh farmers, a multi-scale experimental programme has been established at Pontbren, in mid-Wales, an area of intensive sheep production. The data have been used to support development of a multi-scale modelling methodology to assess impacts of agricultural intensification and the potential for mitigation of flood risk through land use management. Data are available from replicated experimental plots under different land management treatments, from instrumented field and hillslope sites, including tree shelter belts, and from first and second order catchments. Measurements include climate variables, soil water states and hydraulic properties at multiple depths and locations, tree interception, overland flow and drainflow, groundwater levels, and streamflow from multiple locations. Fine resolution physics-based models have been developed to represent soil and runoff processes, conditioned using experimental data. The detailed models are used to calibrate simpler 'meta- models' to represent individual hydrological elements, which are then combined in a semi-distributed catchment-scale model. The methodology is illustrated using field

STS_135_Landing

NASA Image and Video Library

2011-07-21

JSC2011-E-067975 (21 July 2011) --- The sun rises over the space shuttle Atlantis after landing July 21 at the Kennedy Space Center in Florida. The landing completed STS-135, the final mission of the NASA Space Shuttle Program. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

STS_135_Landing

NASA Image and Video Library

2011-07-21

JSC2011-E-067976 (21 July 2011) --- The sun rises over the space shuttle Atlantis after landing July 21 at the Kennedy Space Center in Florida. The landing completed STS-135, the final mission of the NASA Space Shuttle Program. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

The mountain-lowland debate: deforestation and sediment transport in the upper Ganga catchment.

PubMed

Wasson, R J; Juyal, N; Jaiswal, M; McCulloch, M; Sarin, M M; Jain, V; Srivastava, P; Singhvi, A K

2008-07-01

The Himalaya-Gangetic Plain region is the iconic example of the debate about the impact on lowlands of upland land-use change. Some of the scientific aspects of this debate are revisited by using new techniques to examine the role of deforestation in erosion and river sediment transport. The approach is whole-of-catchment, combining a history of deforestation with a history of sediment sources from well before deforestation. It is shown that deforestation had some effect on one very large erosional event in 1970, in the Alaknanda subcatchment of the Upper Ganga catchment, but that both deforestation and its effects on erosion and sediment transport are far from uniform in the Himalaya. Large magnitude erosional events occur for purely natural reasons. The impact on the Gangetic Plain of erosion caused by natural events and land cover change remains uncertain.

Human impact on the geomorphic evolution of the HOAL catchment, Lower Austria

NASA Astrophysics Data System (ADS)

Pöppl, Ronald; Kraushaar, Sabine; Strauss, Peter; Fuchs, Markus

2016-04-01

Since the beginning of human settlement extensive land cover and land use changes have induced significant geomorphic landscape changes as water and sediment dynamics have been transformed. The presented project focuses on the reconstruction of Holocene geomorphic landscape evolution and the assessment of recent geomorphic processes in the Northern foothills of the Eastern Alps in Austria - an area intensively agriculturally used since the middle ages and often overlooked in its geomorphic evolution. The study area is a small catchment (ca. 66 ha) which is located in the western part of Lower Austria comprising a land use history as well as environmental settings typical for wide regions across the Northern foothills of the Eastern Alps in Austria. The catchment elevation ranges from 268 to 323 m a.s.l. and has a mean slope angle of 8%. The climate in this region can be characterized as humid. The lithology mainly consists of Tertiary marly to sandy deposits which are superimposed by Quaternary sediments (e.g. loesses). Dominant soil types are Cambisols, Luvisols, and Planosols. Furthermore, the catchment is used as a Hydrological Open Air Laboratory (HOAL) implemented for the long-term research of water-related flow and transport processes in the landscape (http://hoal.hydrology.at). The main objective of this research project is to reconstruct Holocene landscape evolution by analyzing physical parameters of sediment cores taken from colluvial and alluvial sediment archives with additional 14C and OSL dating as well as by the measurement of truncated and covered standardized Luvisol profiles. First results will be presented at the EGU General Assembly 2016.

Estimating the SCS runoff curve number in forest catchments of Korea

NASA Astrophysics Data System (ADS)

Choi, Hyung Tae; Kim, Jaehoon; Lim, Hong-geun

2016-04-01

To estimate flood runoff discharge is a very important work in design for many hydraulic structures in streams, rivers and lakes such as dams, bridges, culverts, and so on. So, many researchers have tried to develop better methods for estimating flood runoff discharge. The SCS runoff curve number is an empirical parameter determined by empirical analysis of runoff from small catchments and hillslope plots monitored by the USDA. This method is an efficient method for determining the approximate amount of runoff from a rainfall even in a particular area, and is very widely used all around the world. However, there is a quite difference between the conditions of Korea and USA in topography, geology and land use. Therefore, examinations in adaptability of the SCS runoff curve number need to raise the accuracy of runoff prediction using SCS runoff curve number method. The purpose of this study is to find the SCS runoff curve number based on the analysis of observed data from several experimental forest catchments monitored by the National Institute of Forest Science (NIFOS), as a pilot study to modify SCS runoff curve number for forest lands in Korea. Rainfall and runoff records observed in Gwangneung coniferous and broad leaves forests, Sinwol, Hwasoon, Gongju and Gyeongsan catchments were selected to analyze the variability of flood runoff coefficients during the last 5 years. This study shows that runoff curve numbers of the experimental forest catchments range from 55 to 65. SCS Runoff Curve number method is a widely used method for estimating design discharge for small ungauged watersheds. Therefore, this study can be helpful technically to estimate the discharge for forest watersheds in Korea with more accuracy.

Anthropogenic nitrogen sources and exports in a village-scale catchment in Southeast China.

PubMed

Cao, Wenzhi; Hong, Huasheng; Zhang, Yuzhen; Chen, Nengwang; Zeng, Yue; Wang, Weiping

2006-01-01

An experimental village-scale catchment was selected for investigation of nitrogen (N) sources and exports. The mean N application rate over the catchment was 350.2 kg N ha(-1), but this rate varied spatially and temporally. The N leaching loss rate varied from 8.1 to 52.7 kg N ha(-1) under different land use regimes. The average N leaching loss rate was 13.4 kg N ha(-1) over the whole catchment, representing about 3.8% of the total N inputs. The N export rate through stormflows was 28.8 kg N ha(-1), about 8.2% of the total N inputs. Seasonal patterns showed that 95% of N exports through stormflows occurred during July to September in 2002. Overall, the maximum riverine N exports were 12.1% of total N inputs and 15.5% of the inorganic fertilizer N applied. Understanding N sources and exports in a village-scale catchment can provide a knowledge base for amelioration of diffuse agricultural pollution.

Lessons learned for applying a paired-catchment approach in drought analysis

NASA Astrophysics Data System (ADS)

Van Loon, Anne; Rangecroft, Sally; Coxon, Gemma; Agustín Breña Naranjo, José; Van Ogtrop, Floris; Croghan, Danny; Van Lanen, Henny

2017-04-01

by human activities. This issue can generally be overcome by selecting adjacent or nearby catchments. Finally, we found that geology is much more important for paired-catchment analysis of drought than we anticipated based upon the experiences in flood research. For example, in two of the UK pairs, we could not use the results due to differences in geology overruling the human influence. We learned that in the selection of catchments for drought analysis, (hydro)geology should be considered in even more detail. Taking these aspects into account, we concluded that the paired-catchment approach works for evaluating the effects of reservoirs and groundwater abstraction on streamflow drought, but is more challenging for urbanisation. The reasons are more problems in catchment selection, lack of results, and complexity of processes making attribution more difficult. Urbanisation is not a simple land cover change influencing only infiltration and runoff, but it involves all kinds of indirect effects, such as artificial inputs (drainage, sewage return flows) that are very important during low flow periods. For this we would suggest starting in small, well-measured urban catchments, of which all artificial inputs are known. We believe that with the careful selection criteria and accounting for variations in climate and landscape, there is scope for using a paired-catchment approach in hydrological drought research.

Enhancements to NASA's Land Atmosphere Near real-time Capability for EOS (LANCE)

NASA Astrophysics Data System (ADS)

Michael, K.; Davies, D. K.; Schmaltz, J. E.; Boller, R. A.; Mauoka, E.; Ye, G.; Vermote, E.; Harrison, S.; Rinsland, P. L.; Protack, S.; Durbin, P. B.; Justice, C. O.

2016-12-01

NASA's Land, Atmosphere Near real-time Capability for EOS (LANCE) supports application users interested in monitoring a wide variety of natural and man-made phenomena. Near Real-Time (NRT) data and imagery from the AIRS, AMSR2, MISR, MLS, MODIS, OMI and VIIRS instruments are available much quicker than routine processing allows. Most data products are available within 3 hours from satellite observation. NRT imagery are generally available 3-5 hours after observation. This article describes LANCE and enhancements made to LANCE over the last year. These enhancements include: the addition of MISR L1 Georeferenced Radiance and L2 Cloud Motion Vector products, AMSR2 Unified L2B Half-Orbit 25 km EASE-Grid Surface Soil Moisture products and VIIRS VIIRS Day/Night Band, Land Surface Reflectance and Corrected Surface reflectance products. In addition, the selection of LANCE NRT imagery that can be interactively viewed through Worldview and the Global Imagery Browse Services (GIBS) has been expanded. LANCE is also working to ingest and process data from OMPS.

Design and Impacts of Land-Biogenic-Atmosphere Coupling in the NASA-Unified WRF (NU-WRF) Modeling System

NASA Technical Reports Server (NTRS)

Tan, Qian; Santanello, Joseph A., Jr.; Zhou, Shujia; Tao, Zhining; Peters-Lidard, Christa d.; Chn, Mian

2011-01-01

Land-Atmosphere coupling is typically designed and implemented independently for physical (e.g. water and energy) and chemical (e.g. biogenic emissions and surface depositions)-based models and applications. Differences in scale, data requirements, and physics thus limit the ability of Earth System models to be fully coupled in a consistent manner. In order for the physical-chemical-biological coupling to be complete, treatment of the land in terms of surface classification, condition, fluxes, and emissions must be considered simultaneously and coherently across all components. In this study, we investigate a coupling strategy for the NASA-Unified Weather Research and Forecasting (NU-WRF) model that incorporates the traditionally disparate fluxes of water and energy through NASA's LIS (Land Information System) and biogenic emissions through BEIS (Biogenic Emissions Inventory System) and MEGAN (Model of Emissions of Gases and Aerosols from Nature) into the atmosphere. In doing so, inconsistencies across model inputs and parameter data are resolved such that the emissions from a particular plant species are consistent with the heat and moisture fluxes calculated for that land cover type. In turn, the response of the atmospheric turbulence and mixing in the planetary boundary layer (PBL) acts on the identical surface type, fluxes, and emissions for each. In addition, the coupling of dust emission within the NU-WRF system is performed in order to ensure consistency and to maximize the benefit of high-resolution land representation in LIS. The impacts of those self-consistent components on' the simulation of atmospheric aerosols are then evaluated through the WRF-Chem-GOCART (Goddard Chemistry Aerosol Radiation and Transport) model. Overall, this ambitious project highlights the current difficulties and future potential of fully coupled. components. in Earth System models, and underscores the importance of the iLEAPS community in supporting improved knowledge of

STS_135_Landing

NASA Image and Video Library

2011-07-21

JSC2011-E-067687 (21 July 2011) --- The drag chute is deployed as the space shuttle Atlantis lands on July 21 at the Kennedy Space Center in Florida. The landing completed STS-135, the final mission of the NASA Space Shuttle Program. Photo credit: NASA Photo/Houston Chronicle, Smiley N. Pool

Viirs Land Science Investigator-Led Processing System

NASA Astrophysics Data System (ADS)

Devadiga, S.; Mauoka, E.; Roman, M. O.; Wolfe, R. E.; Kalb, V.; Davidson, C. C.; Ye, G.

2015-12-01

The objective of the NASA's Suomi National Polar Orbiting Partnership (S-NPP) Land Science Investigator-led Processing System (Land SIPS), housed at the NASA Goddard Space Flight Center (GSFC), is to produce high quality land products from the Visible Infrared Imaging Radiometer Suite (VIIRS) to extend the Earth System Data Records (ESDRs) developed from NASA's heritage Earth Observing System (EOS) Moderate Resolution Imaging Spectroradiometer (MODIS) onboard the EOS Terra and Aqua satellites. In this paper we will present the functional description and capabilities of the S-NPP Land SIPS, including system development phases and production schedules, timeline for processing, and delivery of land science products based on coordination with the S-NPP Land science team members. The Land SIPS processing stream is expected to be operational by December 2016, generating land products either using the NASA science team delivered algorithms, or the "best-of" science algorithms currently in operation at NASA's Land Product Evaluation and Algorithm Testing Element (PEATE). In addition to generating the standard land science products through processing of the NASA's VIIRS Level 0 data record, the Land SIPS processing system is also used to produce a suite of near-real time products for NASA's application community. Land SIPS will also deliver the standard products, ancillary data sets, software and supporting documentation (ATBDs) to the assigned Distributed Active Archive Centers (DAACs) for archival and distribution. Quality assessment and validation will be an integral part of the Land SIPS processing system; the former being performed at Land Data Operational Product Evaluation (LDOPE) facility, while the latter under the auspices of the CEOS Working Group on Calibration & Validation (WGCV) Land Product Validation (LPV) Subgroup; adopting the best-practices and tools used to assess the quality of heritage EOS-MODIS products generated at the MODIS Adaptive Processing

Using the NASA Giovanni DICCE Portal to Investigate Land-Ocean Linkages with Satellite and Model Data

NASA Technical Reports Server (NTRS)

Acker, James G.; Zalles, Daniel; Krumhansl, Ruth

2012-01-01

Data-enhanced Investigations for Climate Change Education (DICCE), a NASA climate change education project, employs the NASA Giovanni data system to enable teachers to create climate-related classroom projects using selected satellite and assimilated model data. The easy-to-use DICCE Giovanni portal (DICCE-G) provides data parameters relevant to oceanic, terrestrial, and atmospheric processes. Participants will explore land-ocean linkages using the available data in the DICCE-G portal, in particular focusing on temperature, ocean biology, and precipitation variability related to El Ni?o and La Ni?a events. The demonstration includes the enhanced information for educators developed for the DICCE-G portal. The prototype DICCE Learning Environment (DICCE-LE) for classroom project development will also be demonstrated.

Hydrogeomorphological and water quality impacts of oil palm conversion and logging in Sabah, Malaysian Borneo: a multi-catchment approach

NASA Astrophysics Data System (ADS)

Walsh, Rory; Nainar, Anand; Bidin, Kawi; Higton, Sam; Annammala, Kogilavani; Blake, William; Luke, Sarah; Murphy, Laura; Perryman, Emily; Wall, Katy; Hanapi, Jamil

2016-04-01

The last three decades have seen a combination of logging and land-use change across most of the rainforest tropics. This has involved conversion to oil palm across large parts of SE Asia. Although much is now known about the hydrological and sediment transport impacts of logging, relatively little is known about how impacts of oil palm conversion compare with those of logging. Furthermore little is known about the impacts of both on river morphology and water quality. This paper reports some findings of the first phase of a ten-year large-scale manipulative multi-catchment experiment (part of the SAFE - Stability of Altered Forest Ecosystems - Project), based in the upper part of the Brantian Catchment in Sabah, Malaysian Borneo; the project is designed to assess the degree to which adverse impacts of oil palm conversion (on erosion, downstream channel change, water quality and river ecology) might be reduced by retaining buffer zones of riparian forest of varying width from zero to 120 metres. Ten 2 km2 catchments of contrasting land use history have been instrumented since 2011 to record discharge, turbidity, conductivity and water temperature at 5-minute intervals. These comprise 6 repeat-logged catchments being subjected in 2015-16 to conversion to oil palm with varying riparian forest widths; a repeat-logged 'control' catchment; an old regrowth catchment; an oil palm catchment; and a primary forest catchment. In addition, (1) monthly water samples from the catchments have been analysed for nitrates and phosphates, (2) channel cross-sectional change along each stream has been monitored at six-monthly intervals and (3) supplementary surveys have been made of downstream bankfull channel cross-sectional size and water chemistry at a wider range of catchment sites, and (4) sediment cores have been taken and contemporary deposition monitored at a hierarchical network of sites in the large Brantian catchment for geochemical analysis and dating to establish the

Groundwater recharge from point to catchment scale

NASA Astrophysics Data System (ADS)

Leterme, Bertrand; Di Ciacca, Antoine; Laloy, Eric; Jacques, Diederik

2016-04-01

Accurate estimation of groundwater recharge is a challenging task as only a few devices (if any) can measure it directly. In this study, we discuss how groundwater recharge can be calculated at different temporal and spatial scales in the Kleine Nete catchment (Belgium). A small monitoring network is being installed, that is aimed to monitor the changes in dominant processes and to address data availability as one goes from the point to the catchment scale. At the point scale, groundwater recharge is estimated using inversion of soil moisture and/or water potential data and stable isotope concentrations (Koeniger et al. 2015). At the plot scale, it is proposed to monitor the discharge of a small drainage ditch in order to calculate the field groundwater recharge. Electrical conductivity measurements are necessary to separate shallow from deeper groundwater contribution to the ditch discharge (see Di Ciacca et al. poster in session HS8.3.4). At this scale, two or three-dimensional process-based vadose zone models will be used to model subsurface flow. At the catchment scale though, using a mechanistic, process-based model to estimate groundwater recharge is debatable (because of, e.g., the presence of numerous drainage ditches, mixed land use pixels, etc.). We therefore investigate to which extent various types of surrogate models can be used to make the necessary upscaling from the plot scale to the scale of the whole Kleine Nete catchment. Ref. Koeniger P, Gaj M, Beyer M, Himmelsbach T (2015) Review on soil water isotope based groundwater recharge estimations. Hydrological Processes, DOI: 10.1002/hyp.10775

Distributed modelling of hydrologic regime at three subcatchments of Kopaninský tok catchment

NASA Astrophysics Data System (ADS)

Žlábek, Pavel; Tachecí, Pavel; Kaplická, Markéta; Bystřický, Václav

2010-05-01

Kopaninský tok catchment is situated in crystalline area of Bohemo-Moravian highland hilly region, with cambisol cover and prevailing agricultural land use. It is a subject of long term (since 1980's) observation. Time series (discharge, precipitation, climatic parameters...) are nowadays available in 10 min. time step, water quality average daily composit samples plus samples during events are available. Soil survey resulting in reference soil hydraulic properties for horizons and vegetation cover survey incl. LAI measurement has been done. All parameters were analysed and used for establishing of distributed mathematical models of P6, P52 and P53 subcatchments, using MIKE SHE 2009 WM deterministic hydrologic modelling system. The aim is to simulate long-term hydrologic regime as well as rainfall-runoff events, serving the base for modelling of nitrate regime and agricultural management influence in the next step. Mentioned subcatchments differs in ratio of artificial drainage area, soil types, land use and slope angle. The models are set-up in a regular computational grid of 2 m size. Basic time step was set to 2 hrs, total simulated period covers 3 years. Runoff response and moisture regime is compared using spatially distributed simulation results. Sensitivity analysis revealed most important parameters influencing model response. Importance of spatial distribution of initial conditions was underlined. Further on, different runoff components in terms of their origin, flow paths and travel time were separated using a combination of two runoff separation techniques (a digital filter and a simple conceptual model GROUND) in 12 subcatchments of Kopaninský tok catchment. These two methods were chosen based on a number of methods testing. Ordinations diagrams performed with Canoco software were used to evaluate influence of different catchment parameters on different runoff components. A canonical ordination method analyses (RDA) was used to explain one data set

Development of a process-based model to predict pathogen budgets for the Sydney drinking water catchment.

PubMed

Ferguson, Christobel M; Croke, Barry F W; Beatson, Peter J; Ashbolt, Nicholas J; Deere, Daniel A

2007-06-01

In drinking water catchments, reduction of pathogen loads delivered to reservoirs is an important priority for the management of raw source water quality. To assist with the evaluation of management options, a process-based mathematical model (pathogen catchment budgets - PCB) is developed to predict Cryptosporidium, Giardia and E. coli loads generated within and exported from drinking water catchments. The model quantifies the key processes affecting the generation and transport of microorganisms from humans and animals using land use and flow data, and catchment specific information including point sources such as sewage treatment plants and on-site systems. The resultant pathogen catchment budgets (PCB) can be used to prioritize the implementation of control measures for the reduction of pathogen risks to drinking water. The model is applied in the Wingecarribee catchment and used to rank those sub-catchments that would contribute the highest pathogen loads in dry weather, and in intermediate and large wet weather events. A sensitivity analysis of the model identifies that pathogen excretion rates from animals and humans, and manure mobilization rates are significant factors determining the output of the model and thus warrant further investigation.

Concentration-discharge relationships for variably sized streams in Florida: Patterns and drivers in long-term catchment studies

NASA Astrophysics Data System (ADS)

Diamond, J.; Cohen, M.

2012-12-01

Catchment-scale analyses can provide important insight into the processes governing solute sources, transport and storage. Understanding solute dynamics is vital for water management both for accurate predictions of chemical fluxes as well as ecosystem responses to them. This project synthesized long-term (>15 years) hydrochemical data from 80 variably sized (101-105 m2) watersheds in Florida. Our goal was to evaluate scaling effects on flow-solute relationships, and determine the factors that control observed inter-catchment variation. We obtained long term records of a variety of chemical parameters include color, nutrients (N and P), and geogenic solutes (Ca, Si, Mg, Na, Cl) from stations where chemistry and flow data were matched. Catchment attributes (land use, terrain, surface geology) were obtained for each stream as potential covariates. Concentration-discharge relationships were modeled as power functions, the exponents (b) of which were categorized into three end-member scenarios: (1) b>0, or chemodynamic conditions, where increased discharge increases concentration, (2) b=0, or chemostatic conditions, where concentration is independent of discharge, and (3) b<0, or dilution conditions, where increased discharge decreases concentrations. Color was strongly chemodynamic, while geogenic solutes tended to be chemostatic;nutrient-flow relationships varied substantially (from dilution to chemodynamic) suggesting important ancillary controls. To assess between-site variability, power function exponents were compared against land use and catchment area. These results indicate that watersheds dominated by urban land use exhibit stronger dilution effects for most solutes while watersheds dominated by agricultural land use were generally chemostatic particularly for nutrients. This synthesis approach to understanding controls on observed concentration-discharge relationships is crucial to understanding the dynamics and early-warning indicators of anthropogenically

Estimating of the impact of land use changes using the conceptual hydrological model THESEUS??a case study

NASA Astrophysics Data System (ADS)

Wegehenkel, Martin

As a result of a new agricultural funding policy established in 1992 by the European Community, it was assumed that up to 15-20% of arable land would have been set aside in the next years in the new federal states of north-eastern Germany, for example, Brandenburg. As one potential land use option, afforestation of these set aside areas was discussed to obtain deciduous forests. Since the mean annual precipitation in north-eastern Germany, Brandenburg is relatively low (480-530 mm y -1), an increase in interception and evapotranspiration loss by forests compared to arable land would lead to a reduction in ground water recharge. Experimental evidence to determine effects of such land use changes are rarely available. Therefore, there is a need for indirect methods to estimate the impact of afforestation on the water balance of catchments. In this paper, a conceptual hydrological model was verified and calibrated in two steps using data from the Stobber-catchment located in Brandenburg. In the first step, model outputs like daily evapotranspiration rates and soil water contents were verified on the basis of experimental data sets from two test locations. One test site with the land use arable land was located within the Stobber-catchment. The other test site with pine forest was located near by the catchment. In the second step, the model was used to estimate the impact of afforestation on catchment water balance and discharge. For that purpose, the model was calibrated against daily discharge measurements for the period 1995-1997. For a simple afforestation scenario, it was assumed that the area of forest increases from 34% up to 80% of the catchment area. The impact of this change in forest cover proportion was analyzed using the calibrated model. In case of increasing the proportion of forest cover in the catchment due to the scenario afforestation, the model predicts a reduction in discharge and an increase in evapotranspiration.

Proximate and ultimate controls on carbon and nutrient dynamics of small agricultural catchments

NASA Astrophysics Data System (ADS)

Thomas, Zahra; Abbott, Benjamin W.; Troccaz, Olivier; Baudry, Jacques; Pinay, Gilles

2016-03-01

Direct and indirect effects from human activity have dramatically increased nutrient loading to aquatic inland and estuarine ecosystems. Despite an abundance of studies investigating the impact of agricultural activity on water quality, our understanding of what determines the capacity of a watershed to remove or retain nutrients remains limited. The goal of this study was to identify proximate and ultimate controls on dissolved organic carbon and nutrient dynamics in small agricultural catchments by investigating the relationship between catchment characteristics, stream discharge, and water chemistry. We analyzed a 5-year, high-frequency water chemistry data set from three catchments in western France ranging from 2.3 to 10.8 km2. The relationship between hydrology and solute concentrations differed between the three catchments and was associated with hedgerow density, agricultural activity, and geology. The catchment with thicker soil and higher surface roughness had relatively invariant carbon and nutrient chemistry across hydrologic conditions, indicating high resilience to human disturbance. Conversely, the catchments with smoother, thinner soils responded to both intra- and interannual hydrologic variation with high concentrations of phosphate (PO43-) and ammonium (NH4+) in streams during low flow conditions and strong increases in dissolved organic carbon (DOC), sediment, and particulate organic matter during high flows. Despite contrasting agricultural activity between catchments, the physical context (geology, topography, and land-use configuration) appeared to be the most important determinant of catchment solute dynamics based on principle components analysis. The influence of geology and accompanying topographic and geomorphological factors on water quality was both direct and indirect because the distribution of agricultural activity in these catchments is largely a consequence of the geologic and topographic context. This link between inherent

Estimating retention potential of headwater catchment using Tritium time series

NASA Astrophysics Data System (ADS)

Hofmann, Harald; Cartwright, Ian; Morgenstern, Uwe

2018-06-01

have a significant storage capacity and that the relationship between long-water stores and fast storm event subsurface flow is complex. The study also illustrates that using 3H to determine mean transit times is probably only valid for baseflow conditions where the catchment can be represented as a single store. The results of this study reinforce the need to protect headwater catchments from contamination and extreme land use changes.

Controls on old and new water contributions to stream flow at some nested catchments in Vermont, USA

USGS Publications Warehouse

Shanley, J.B.; Kendall, C.; Smith, T.E.; Wolock, D.M.; McDonnell, Jeffery J.

2002-01-01

Factors controlling the partitioning of old and new water contributions to stream flow were investigated for three events in four catchments (three of which were nested) at Sleepers River Research Watershed in Danville, Vermont. In the 1993 snowmelt period, two-component isotopic hydrograph separations showed that new water (meltwater) inputs to the stream ranged widely from 41 to 74%, and increased with catchment size (41 to 11 125 ha) (with one exception) and with open land cover (0-73%). Peak dissolved organic carbon concentrations and relative alkalinity dilution in stream water ranked in the same order among catchments as the new water fractions, suggesting that new water followed shallow flow paths. During the 1994 snowmelt, despite similar timing and magnitude of melt inputs, the new-water contribution to stream flow ranged only from 30 to 36% in the four catchments. We conclude that the uncommonly high and variable new water fractions in streamwater during the 1993 melt were caused by direct runoff of meltwater over frozen ground, which was prevalent in open land areas during the 1993 winter. In a high-intensity summer rainstorm in 1993, new water fractions were smaller relative to the 1993 snowmelt, ranging from 28 to 46%, but they ranked in the identical catchment order. Reconciliation of the contrasting patterns of new-old water partitioning in the three events appears to require an explanation that invokes multiple processes and effects, including: 1 topographically controlled increase in surface-saturated area with increasing catchment size; 2 direct runoff over frozen ground; 3 low infiltration in agriculturally compacted soils; 4 differences in soil transmissivity, which may be more relevant under dry antecedent conditions. These data highlight some of the difficulties faced by catchment hydrologists in formulating a theory of runoff generation at varying basin scales. Copyright ?? 2002 John Wiley and Sons, Ltd.

Controls on old and new water contributions to stream flow at some nested catchments in Vermont, USA

NASA Astrophysics Data System (ADS)

Shanley, James B.; Kendall, Carol; Smith, Thor E.; Wolock, David M.; McDonnell, Jeffrey J.

2002-02-01

Factors controlling the partitioning of old and new water contributions to stream flow were investigated for three events in four catchments (three of which were nested) at Sleepers River Research Watershed in Danville, Vermont. In the 1993 snowmelt period, two-component isotopic hydrograph separations showed that new water (meltwater) inputs to the stream ranged widely from 41 to 74%, and increased with catchment size (41 to 11 125 ha) (with one exception) and with open land cover (0-73%). Peak dissolved organic carbon concentrations and relative alkalinity dilution in stream water ranked in the same order among catchments as the new water fractions, suggesting that new water followed shallow flow paths. During the 1994 snowmelt, despite similar timing and magnitude of melt inputs, the new-water contribution to stream flow ranged only from 30 to 36% in the four catchments. We conclude that the uncommonly high and variable new water fractions in streamwater during the 1993 melt were caused by direct runoff of meltwater over frozen ground, which was prevalent in open land areas during the 1993 winter. In a high-intensity summer rainstorm in 1993, new water fractions were smaller relative to the 1993 snowmelt, ranging from 28 to 46%, but they ranked in the identical catchment order. Reconciliation of the contrasting patterns of new-old water partitioning in the three events appears to require an explanation that invokes multiple processes and effects, including: 1.topographically controlled increase in surface-saturated area with increasing catchment size;2.direct runoff over frozen ground;3.low infiltration in agriculturally compacted soils;4.differences in soil transmissivity, which may be more relevant under dry antecedent conditions. These data highlight some of the difficulties faced by catchment hydrologists in formulating a theory of runoff generation at varying basin scales.

Effects of future climate and land use scenarios on riverine source water quality.

PubMed

Delpla, Ianis; Rodriguez, Manuel J

2014-09-15

Surface water quality is particularly sensitive to land use practices and climatic events that affect its catchment. The relative influence of a set of watershed characteristics (climate, land use, morphology and pedology) and climatic variables on two key water quality parameters (turbidity and fecal coliforms (FC)) was examined in 24 eastern Canadian catchments at various spatial scales (1 km, 5 km, 10 km and the entire catchment). A regression analysis revealed that the entire catchment was a better predictor of water quality. Based on this information, linear mixed effect models for predicting turbidity and FC levels were developed. A set of land use and climate scenarios was considered and applied within the water quality models. Four land use scenarios (no change, same rate of variation, optimistic and pessimistic) and three climate change scenarios (B1, A1B and A2) were tested and variations for the near future (2025) were assessed and compared to the reference period (2000). Climate change impacts on water quality remained low annually for this time horizon (turbidity: +1.5%, FC: +1.6%, A2 scenario). On the other hand, the influence of land use changes appeared to predominate. Significant benefits for both parameters could be expected following the optimistic scenario (turbidity: -16.4%, FC: -6.3%; p < 0.05). However, pessimistic land use scenario led to significant increases on an annual basis (turbidity: +11.6%, FC: +15.2%; p < 0.05). Additional simulations conducted for the late 21st century (2090) revealed that climate change impacts could become equivalent to those modeled for land use for this horizon. Copyright © 2014 Elsevier B.V. All rights reserved.

Hillslope degradation in small Mediterranean catchments along the Apennine chain in Italy

NASA Astrophysics Data System (ADS)

Brandolini, Pierluigi; Capolongo, Domenico; Cappadonia, Chiara; Cevasco, Andrea; Conoscenti, Christian; Del Monte, Maurizio; Pepe, Giacomo; Piccarreta, Marco; Vergari, Francesca

2017-04-01

In this research, the results coming from the investigation of some small catchments located along the Apennines (Italy) affected by hillslope degradation are presented. Four key study areas, particularly sensitive to climatic and anthropic changes, have been selected in Liguria (Cinque Terre), Tuscany (Val d'Orcia), Basilicata (Fossa Bradanica)) and Sicily (Scillato) regions. These areas are characterized by different climatic and geological conditions, orographic and tectonic settings, land use evolution and land management practices. All of them recorded very severe landscape changes in the last few centuries, because of unsustainable anthropogenic modification together with their increasing proneness to fast erosion by mass movements and runoff on slopes. Hence, degradation processes are widespread in the selected areas leading to loss and depletion of soil, economic damage, risk conditions and environmental changes. Interestingly, despite the small extent, the selected basins can be considered representative of the land degradation issues that occurred at the wider regional scale. The obtained results show that the maximum denudation effects occur during occasional but extreme rainfall events that can mobilize, in a few hours or days, the total annual sediment yield estimated for a single catchment and for a single slope. Furthermore, the case studies revealed that land mismanagement has a crucial impact in increasing the erosion rates, especially when crop-land are abandoned and/or land maintenance practices are no longer carried out. Since hillslope degradation, together with the recent changes in the rainfall regime and in land use, can lead to an increasing in both geomorphological hazard and risk, our findings can contribute: (i) to define a proper land management; (ii) to support the decision-making; (iii) to schedule an effective strategy for landscape conservation and its enhancement.

Catchment-scale determinants of nonindigenous minnow richness in the eastern United States

USGS Publications Warehouse

Peoples, Brandon K.; Midway, Stephen R.; DeWeber, Jefferson T.; Wagner, Tyler

2018-01-01

Understanding the drivers of biological invasions is critical for preserving aquatic biodiversity. Stream fishes make excellent model taxa for examining mechanisms driving species introduction success because their distributions are naturally limited by catchment boundaries. In this study, we compared the relative importance of catchment-scale abiotic and biotic predictors of native and nonindigenous minnow (Cyprinidae) richness in 170 catchments throughout the eastern United States. We compared historic and contemporary cyprinid distributional data to determine catchment-wise native/nonindigenous status for 152 species. Catchment-scale model predictor variables described natural (elevation, precipitation, flow accumulation) and anthropogenic (developed land cover, number of dams) abiotic features, as well as native congener richness. Native congener richness may represent either biotic resistance via interspecific competition, or trait preadaptation according to Darwin's naturalisation hypothesis. We used generalised linear mixed models to examine evidence supporting the relative roles of abiotic and biotic predictors of cyprinid introduction success. Native congener richness was positively correlated with nonindigenous cyprinid richness and was the most important variable predicting nonindigenous cyprinid richness. Mean elevation had a weak positive effect, and effects of other abiotic factors were insignificant and less important. Our results suggest that at this spatial scale, trait preadaptation may be more important than intrageneric competition for determining richness of nonindigenous fishes.

CNMM: a Catchment Environmental Model for Managing Water Quality and Greenhouse Gas Emissions

NASA Astrophysics Data System (ADS)

Li, Y.

2015-12-01

Mitigating agricultural diffuse pollution and greenhouse gas emissions is a complicated task due to tempo-spatial lags between the field practices and the watershed responses. Spatially-distributed modeling is essential to the implementation of cost-effective and best management practices (BMPs) to optimize land uses and nutrient applications as well as to project the impact of climate change on the watershed service functions. CNMM (the Catchment Nutrients Management Model) is a 3D spatially-distributed, grid-based and process-oriented biophysical model comprehensively developed to simulate energy balance, hydrology, plant/crop growth, biogeochemistry of life elements (e.g., C, N and P), waste treatment, waterway vegetation/purification, stream water quality and land management in agricultural watersheds as affected by land utilization strategies such as BMPs and by climate change. The CNMM is driven by a number of spatially-distributed data such as weather, topography (including DEM and shading), stream network, stream water, soil, vegetation and land management (including waste treatments), and runs at an hourly time step. It represents a catchment as a matrix of square uniformly-sized cells, where each cell is defined as a homogeneous hydrological response unit with all the hydrologically-significant parameters the same but varied at soil depths in fine intervals. Therefore, spatial variability is represented by allowing parameters to vary horizontally and vertically in space. A four-direction flux routing algorithm is applied to route water and nutrients across soils of cells governed by the gradients of either water head or elevation. A linear channel reservoir scheme is deployed to route water and nutrients in stream networks. The model is capable of computing CO2, CH4, NH3, NO, N2O and N2 emissions from soils and stream waters. The CNMM can serve as an idea modelling tool to investigate the overwhelming critical zone research at various catchment scales.

Human-induced landscape changes and geo-hydrological risk: the Rupinaro catchment, Liguria, Italy

NASA Astrophysics Data System (ADS)

Giostrella, Paola; Faccini, Francesco; Maggi, Roberto; Cesare Mondini, Alessandro; Tarolli, Paolo; Guzzetti, Fausto

2015-04-01

Small and steep watersheds are typical of Liguria, northern Italy. In these small watersheds, geo-hydrological hazards, including flash floods and shallow landslides, caused by high intensity rainfall are frequent and abundant. In the coastal valleys of Liguria, narrow flood plains have hosted human settlements and communication lines since the protohistoric period. Since then, a variety of human activities have modified the natural landscape significantly, and chiefly through land-use changes first in the flood-plains, and next along the slopes. We have studied the 11-square km Rupinaro catchment, west of Chiavari, which has been inhabited since the 8th century BC. Progressive human actions have modified the main river and its tributaries, which have become narrower and canalized, and locally they were covered completely. Human actions have also contributed to the increase in the runoff coefficients, and to the progradation of the main river into the Ligurian Sea. Demographic growth, socio-economic development and urbanization are the main drivers for the land use changes occurred in the Rupinaro catchment. Through a combined analysis of archaeological and palynologycal data, and the multi-temporal analysis of historical maps, aerial photographs and satellite imagery of different vintages, we have reconstructed phases of modifications of the river and the tributaries. We determined the land use changes calculating the loss of soil, analyzing statistics of buildings and demography for the last 150 years, and interpreting historical maps and aerial and satellite imagery. We found that land reclamations, the construction of embankments, and the rectification of rivers are the main human actions performed to obtain building areas along the main river course. Expansion of urban settlements in flood prone areas, and even in the main riverbed, have reached a critical limit has shown by the destructive flood event that has affected the Rupinaro catchment, and chiefly the

The ethics of socio-ecohydrological catchment management: towards hydrosolidarity

NASA Astrophysics Data System (ADS)

Falkenmark, M.; Folke, Carl

This paper attempts to clarify key biophysical issues and the problems involved in the ethics of socio-ecohydrological catchment management. The issue in managing complex systems is to live with unavoidable change while securing the capacity of the ecohydrological system of the catchment to sustain vital ecological goods and services, aquatic as well as terrestrial, on which humanity depends ultimately. Catchment management oriented to sustainability has to be based on ethical principles: human rights, international conventions, sustaining crucial ecological goods and services, and protecting ecosystem resilience, all of which have water linkages. Many weaknesses have to be identified, assessed and mitigated to improve the tools by which the ethical issues can be addressed and solved:

• a heritage of constraining tunnel vision in both science and management;
• inadequate shortcuts made in modern scientific system analyses (e.g. science addressing sustainability issues);
• simplistic technical-fix approaches to water and ecosystems in land/water/ecosystem management;
• conventional tools for evaluation of scientific quality with its focus on "doing the thing right" rather than "doing the right thing".

The new ethics have to incorporate principles that, on a catchment basis, allow for proper attention to the hungry and poor, upstream and downstream, to descendants, and to sites and habitats that need to be protected.

Fluvial dissolved organic carbon composition varies spatially and seasonally in a small catchment draining a wind farm and felled forestry.

PubMed

Zheng, Ying; Waldron, Susan; Flowers, Hugh

2018-06-01

Assessing whether land use, from activities such as wind farm construction and tree-felling, impacts on terrestrial C delivery to rivers has focused on quantifying the loss of dissolved organic carbon (DOC), and not the composition changes. Here we explore how land use influences DOC composition by considering fluvial DOC concentration, [DOC], and spectrophotometric composition of a river draining a peat-rich catchment. We find that in this 5.7km 2 catchment differences occur in both the concentration and composition of the DOC in its sub-catchments. This is attributed to differences in how land was used: one tributary (D-WF) drains an area with wind farm construction and forestry in the headwaters, and one tributary (D-FF) drains an area with felled plantation trees. Generally, [DOC] in both streams showed similar seasonal variation, and autumn maxima. However, the felled catchment had greater mean [DOC] than the wind farm catchment. The SUVA 254 and E 4 /E 6 indicated DOC in both streams had similar aromaticity and fulvic:humic acid for most of the time, but SUVA 410 and E 2 /E 4 indicated less DOC humification in the felled catchment. This may be due to young DOC from the breakdown of residual branches and roots, or more humification in soils in the wind farm area. During the dry months, DOC composition showed more spatial variation: the D-WF DOC had smaller SUVA 254 (less total aromatic material) and SUVA 410 (fewer humic substances). The decreased E 2 /E 4 in both streams indicated the total aromatic carbon decreased more than humic substances content. Moreover, the larger E 4 /E 6 for D-WF in summer indicated that the humic substances were richer in fulvic acids than humic acids. Soil disturbance associated with forestry-felling likely contributed to the higher [DOC] and release of less-humified material in D-FF. This research indicates drivers of different DOC concentration and composition can exist even in small catchments. Copyright © 2018 Elsevier B

Role of the check dam in land development on the Loess Plateau, China

NASA Astrophysics Data System (ADS)

Xu, Xiang-Zhou; Zhang, Luo-Hao; Zhu, Tongxin; Dang, Tian-Min; Zhang, Hong-Wu; Xu, Shi-Guo

2017-04-01

Check dam is one of the most effective measures to reduce flow connectivity, which can retain soil and water, and increase land productivity. More than 100,000 check dams have been built on the Loess Plateau since 1950s. However, quantifying the effect of check dams on water resources and water environments remains a challenge. In this study, an in-depth field investigation together with a credible statistical analysis was carried out in two representative catchments on the Loess Plateau, Nanxiaohegou Catchment and Jiuyuangou Catchment, to assess the effectiveness of check dams in soil, water and nutrients conservation. The results show: (1) Check dam plays an important role in conserving water, soil, and nutrients on the Loess Plateau. About half of the total transported water and more than 80 % of the total transported soil and nutrients, had been locally retained in the selected catchments. Hence check dams had a significant benefit to improve soil fertility in the small watersheds, and reducing water pollution downstream of dams. (2) Compared to terrace farmlands, forest lands and grasslands, check-dam lands were much more important in conserving water, soil and nutrients in the catchments. Nearly 50% of the reduced water and more than 70% of the stored soil and nutrients in the study catchments were solely retained by the check dams, whereas the area of the dam lands was less than 7% of the total conservation land area. (3) Check dams are still effective in large storms even if dams were damaged by floods. It is often assumed that check dams could only retain sediment in small flood events whereas most of the stored soil may be washed out as the dams may be destroyed in a disastrous flood. Furthermore, if a major check dam, namely the key project dam, was built in the gully outlet, the flood could be controlled, and thereupon the dam-break can be also avoided. We suggest that a compensation and incentive policy be implemented on dam building to realize the

Soil erosion modelling for NSW coastal catchments using RUSLE in a GIS environment

NASA Astrophysics Data System (ADS)

Yang, Xihua; Chapman, Greg

2006-10-01

In this study, hillslope erosion risk has been estimated for all eastern New South Wales (NSW) catchments, Australia using Revised Universal Soil Loss Equation (RUSLE) in a geographic information system (GIS) environment. Rainfall-runoff erosivity (R) factor was interpolated from NSW rainfall-erosivity contour (isoerodent) data. Soil erodibility (K) factor was based on the soil regolith stability and sediment yield classification. The classification was derived from soil landscape and related soil map data. The slope length and steepness (LS) factor was derived from high resolution digital elevation model (DEM). A fully-automated program using Arc Macro Language (AML) produced RUSLE-based LS factor grids for all coastal catchments. The outputs are comparable to the range of LS values summarised in the literature. Cover and management (C) factor and conservation support-practices (P) factor were set to one. They are intended to be allocated according to land use, ground cover and erosion control provisions for particular land management actions. The resulting erosion risk map, with pixel size of 25-m, provides unprecedented resolution of relative expected sheet and rill erosion across all NSW costal catchments and can be adapted for a range of erosion control purposes such as bushfire hazard reduction and comprehensive costal assessment.

Conversion of forest to arable land in Southern Brazil has led to an increase in dissolved silicon flux

NASA Astrophysics Data System (ADS)

Robinet, Jérémy; Ameijeiras-Mariño, Yolanda; Vanderborght, Jan; Opfergelt, Sophie; Govers, Gerard

2017-04-01

Hydrology plays a major role in controlling biogeochemical fluxes at various scales. Among the various controlling factors of water fluxes at the hillslope or catchment scale, land use change is a direct human effect which has been relatively under-examined despite its potential important impact. The overall objective of this research is therefore to investigate how land use change can affect water fluxes and how these changes may, on their turn, affect biogeochemical fluxes, with a particular focus on silicon (Si) dynamic. We selected two small catchments with contrasting land use (agriculture vs. natural forest) in a subtropical region in the south of Brazil. The conversion of forest to arable land in the agricultural catchment is relatively recent, as deforestation started at the beginning of the 20th century. Stream, pore and groundwater were monitored, sampled and analyzed for major elements concentrations and δ18O. Preliminary results showed that deforestation and agriculture led to an increase in solute export at the catchment outlet, with for example dissolved Si (DSi) concentration and flux two times higher for the agricultural catchment. δ18O and DSi concentration data showed the importance of preferential flow in macropores in the forested catchment, probably because of the high root and low bulk densities. This led to a reduced mobilization of the pore water during rainfall event, contrarily to the agricultural catchment. As a result, there is almost no contribution of this relatively DSi-enriched pool to the river discharge in the forested environment. Those results indicate that the conversion of forest to arable land has had a significant impact on the biogeochemical fluxes, highlighted in this study with observed changes in DSi flux. Those changes could be partially attributed to changes in water fluxes and pathways.

Modeling the behavior of an ungauged catchment using alternative datasets: a case study of the Caribou catchment in Canada

NASA Astrophysics Data System (ADS)

Labrecque, Geneviève; Boucher, Marie-Amélie; Chesnaux, Romain

2017-04-01

The modelling of ungauged catchments is a long standing problem in hydrology and there is still no general consensus regarding the best practices to adopt in a variety of situations. In addition to flood and drought forecasting, there are other interests of modelling the hydrological behaviour of a catchment, whether it is gauged or not. For instance, estimation of groundwater recharge can be performed through an integrated modeling of the catchment. In this study, the WaSim model is used to model the hydrology of the Caribou River catchment located in the province of Quebec, in Canada. Since this catchment includes an important aquifer that is used both for drinking water, industrial and potential agricultural purposes, an accurate recharge assessment is important and is the long-term objective of the project. The WaSim model was chosen due to its very versatile soil sub-model features which allow to simulate subsurface flows and calculate the groundwater recharge as an output variable. Since the Caribou River is ungauged, alternative means of calibrating the free parameters of WaSim had to be implemented. The implementation of a calibration protocol that can get the most out of the few available data is a secondary objective and is the subject of this presentation. First, a « twin » gauged catchment is selected for its physiographic and hydro-climatic similarities with the Caribou River catchment. Streamflow series from this « twin » catchment are then transferred and used jointly with the dynamically dimensioned search (DDS) algorithm (Tolson and Shoemaker 2007) to obtain a raw calibration of the WaSim model parameters. This initial calibration can be further refined using two available datasets: (1) snow water equivalent data interpolated on a 10 km by 10 km grid and (2) a short and discontinuous time series of streamflow obtained using the land-surface scheme of the environmental multiscale atmospheric model (GEM) at Environment and Climate Change Canada

Historical land-use influences the long-term stream turbidity response to a wildfire.

PubMed

Harrison, Evan T; Dyer, Fiona; Wright, Daniel W; Levings, Chris

2014-02-01

Wildfires commonly result in an increase in stream turbidity. However, the influence of pre-fire land-use practices on post-fire stream turbidity is not well understood. The Lower Cotter Catchment (LCC) in south-eastern Australia is part of the main water supply catchment for Canberra with land in the catchment historically managed for a mix of conservation (native eucalypt forest) and pine (Pinus radiata) plantation. In January 2003, wildfires burned almost all of the native and pine forests in the LCC. A study was established in 2005 to determine stream post-fire turbidity recovery within the native and pine forest areas of the catchment. Turbidity data loggers were deployed in two creeks within burned native forest and burned pine forest areas to determine turbidity response to fire in these areas. As a part of the study, we also determined changes in bare soil in the native and pine forest areas since the fire. The results suggest that the time, it takes turbidity levels to decrease following wildfire, is dependent upon the preceding land-use. In the LCC, turbidity levels decreased more rapidly in areas previously with native vegetation compared to areas which were previously used for pine forestry. This is likely because of a higher percentage of bare soil areas for a longer period of time in the ex-pine forest estate and instream stores of fine sediment from catchment erosion during post-fire storm events. The results of our study show that the previous land-use may exert considerable control over on-going turbidity levels following a wildfire.

Parameter Set Cloning Based on Catchment Similarity for Large-scale Hydrologic Modeling

NASA Astrophysics Data System (ADS)

Liu, Z.; Kaheil, Y.; McCollum, J.

2016-12-01

Parameter calibration is a crucial step to ensure the accuracy of hydrological models. However, streamflow gauges are not available everywhere for calibrating a large-scale hydrologic model globally. Thus, assigning parameters appropriately for regions where the calibration cannot be performed directly has been a challenge for large-scale hydrologic modeling. Here we propose a method to estimate the model parameters in ungauged regions based on the values obtained through calibration in areas where gauge observations are available. This parameter set cloning is performed according to a catchment similarity index, a weighted sum index based on four catchment characteristic attributes. These attributes are IPCC Climate Zone, Soil Texture, Land Cover, and Topographic Index. The catchments with calibrated parameter values are donors, while the uncalibrated catchments are candidates. Catchment characteristic analyses are first conducted for both donors and candidates. For each attribute, we compute a characteristic distance between donors and candidates. Next, for each candidate, weights are assigned to the four attributes such that higher weights are given to properties that are more directly linked to the hydrologic dominant processes. This will ensure that the parameter set cloning emphasizes the dominant hydrologic process in the region where the candidate is located. The catchment similarity index for each donor - candidate couple is then created as the sum of the weighted distance of the four properties. Finally, parameters are assigned to each candidate from the donor that is "most similar" (i.e. with the shortest weighted distance sum). For validation, we applied the proposed method to catchments where gauge observations are available, and compared simulated streamflows using the parameters cloned by other catchments to the results obtained by calibrating the hydrologic model directly using gauge data. The comparison shows good agreement between the two models

Assessing the role of urban developments on storm runoff response through multi-scale catchment experiments

NASA Astrophysics Data System (ADS)

Wilkinson, Mark; Owen, Gareth; Geris, Josie; Soulsby, Chris; Quinn, Paul

2015-04-01

Many communities across the world face the increasing challenge of balancing water quantity and quality issues with accommodating new growth and urban development. Urbanisation is typically associated with detrimental changes in water quality, sediment delivery, and effects on water storage and flow pathways (e.g. increases in flooding). In particular for mixed rural and urban catchments where the spatio-temporal variability of hydrological responses is high, there remains a key research challenge in evaluating the timing and magnitude of storage and flow pathways at multiple scales. This is of crucial importance for appropriate catchment management, for example to aid the design of Green Infrastructure (GI) to mitigate the risk of flooding, among other multiple benefits. The aim of this work was to (i) explore spatio-temporal storm runoff generation characteristics in multi-scale catchment experiments that contain rural and urban land use zones, and (ii) assess the (preliminary) impact of Sustainable Drainage (SuDs) as GI on high flow and flood characteristics. Our key research catchment, the Ouseburn in Northern England (55km2), has rural headwaters (15%) and an urban zone (45%) concentrated in the lower catchment area. There is an intermediate and increasingly expanding peri-urban zone (currently 40%), which is defined here as areas where rural and urban features coexist, alongside GIs. Such a structure is typical for most catchments with urban developments. We monitored spatial precipitation and multiscale nested (five gauges) runoff response, in addition to the storage dynamics in GIs for a period of 6 years (2007-2013). For a range of events, we examined the multiscale nested runoff characteristics (lag time and magnitude) of the rural and urban flow components, assessed how these integrated with changing land use and increasing scale, and discussed the implications for flood management in the catchment. The analyses indicated three distinctly different

Evaluating the Impacts of NASA/SPoRT Daily Greenness Vegetation Fraction on Land Surface Model and Numerical Weather Forecasts

NASA Technical Reports Server (NTRS)

Bell, Jordan R.; Case, Jonathan L.; Molthan, Andrew L.

2011-01-01

The NASA Short-term Prediction Research and Transition (SPoRT) Center develops new products and techniques that can be used in operational meteorology. The majority of these products are derived from NASA polar-orbiting satellite imagery from the Earth Observing System (EOS) platforms. One such product is a Greenness Vegetation Fraction (GVF) dataset, which is produced from Moderate Resolution Imaging Spectroradiometer (MODIS) data aboard the NASA EOS Aqua and Terra satellites. NASA SPoRT began generating daily real-time GVF composites at 1-km resolution over the Continental United States (CONUS) on 1 June 2010. The purpose of this study is to compare the National Centers for Environmental Prediction (NCEP) climatology GVF product (currently used in operational weather models) to the SPoRT-MODIS GVF during June to October 2010. The NASA Land Information System (LIS) was employed to study the impacts of the new SPoRT-MODIS GVF dataset on land surface models apart from a full numerical weather prediction (NWP) model. For the 2010 warm season, the SPoRT GVF in the western portion of the CONUS was generally higher than the NCEP climatology. The eastern CONUS GVF had variations both above and below the climatology during the period of study. These variations in GVF led to direct impacts on the rates of heating and evaporation from the land surface. The second phase of the project is to examine the impacts of the SPoRT GVF dataset on NWP using the Weather Research and Forecasting (WRF) model. Two separate WRF model simulations were made for individual severe weather case days using the NCEP GVF (control) and SPoRT GVF (experimental), with all other model parameters remaining the same. Based on the sensitivity results in these case studies, regions with higher GVF in the SPoRT model runs had higher evapotranspiration and lower direct surface heating, which typically resulted in lower (higher) predicted 2-m temperatures (2-m dewpoint temperatures). The opposite was true

Benefit from NASA

NASA Image and Video Library

1999-01-01

The same rocket fuel that helps power the Space Shuttle as it thunders into orbit will now be taking on a new role, with the potential to benefit millions of people worldwide. Leftover rocket fuel from NASA is being used to make a flare that destroys land mines where they were buried, without using explosives. The flare is safe to handle and easy to use. People working to deactivate the mines simply place the flare next to the uncovered land mine and ignite it from a safe distance using a battery-triggered electric match. The flare burns a hole in the land mine's case and ignites its explosive contents. The explosive burns away, disabling the mine and rendering it harmless. Using leftover rocket fuel to help destroy land mines incurs no additional costs to taxpayers. To ensure enough propellant is available for each Shuttle mission, NASA allows for a small percentage of extra propellant in each batch. Once mixed, surplus fuel solidifies and carnot be saved for use in another launch. In its solid form, it is an ideal ingredient for the new flare. The flare was developed by Thiokol Propulsion in Brigham City, Utah, the NASA contractor that designs and builds rocket motors for the Solid Rocket Booster Space Shuttle. An estimated 80 million or more active land mines are scattered around the world in at least 70 countries, and kill or maim 26,000 people a year. Worldwide, there is one casualty every 22 minutes

Influences of the land use pattern on water quality in low-order streams of the Dongjiang River basin, China: A multi-scale analysis.

PubMed

Ding, Jiao; Jiang, Yuan; Liu, Qi; Hou, Zhaojiang; Liao, Jianyu; Fu, Lan; Peng, Qiuzhi

2016-05-01

Understanding the relationships between land use patterns and water quality in low-order streams is useful for effective landscape planning to protect downstream water quality. A clear understanding of these relationships remains elusive due to the heterogeneity of land use patterns and scale effects. To better assess land use influences, we developed empirical models relating land use patterns to the water quality of low-order streams at different geomorphic regions across multi-scales in the Dongjiang River basin using multivariate statistical analyses. The land use pattern was quantified in terms of the composition, configuration and hydrological distance of land use types at the reach buffer, riparian corridor and catchment scales. Water was sampled under summer base flow at 56 low-order catchments, which were classified into two homogenous geomorphic groups. The results indicated that the water quality of low-order streams was most strongly affected by the configuration metrics of land use. Poorer water quality was associated with higher patch densities of cropland, orchards and grassland in the mountain catchments, whereas it was associated with a higher value for the largest patch index of urban land use in the plain catchments. The overall water quality variation was explained better by catchment scale than by riparian- or reach-scale land use, whereas the spatial scale over which land use influenced water quality also varied across specific water parameters and the geomorphic basis. Our study suggests that watershed management should adopt better landscape planning and multi-scale measures to improve water quality. Copyright © 2016 Elsevier B.V. All rights reserved.

[Difference of Karst Carbon Sink Under Different Land Use and Land Cover Areas in Dry Season].

PubMed

Zhao, Rui-yi; Liang, Zuo-bing; Wang, Zun-bo; Yu, Zheng-liang; Jiang, Ze-li

2015-05-01

In order to identify the distinction of soil CO2 consumed by carbonate rock dissolution, Baishuwan spring, Lanhuagou spring and Hougou spring were selected as objects to monitor the hydrochemistry from November 2013 to May 2014. The results showed that the highest HCO3- concentration was observed in Baishuwan spring which is covered by pine forest, while the lowest HCO3- concentration was observed in Hougou spring which is mainly covered by cultivated land. In Baishuwan spring, HCO3- was mainly derived from carbonic acid dissolving carbonate rock and the molar ratio between Ca(2+) + Mg2+ and HCO3- was close to 0. 5; while the molar ratio between Ca(2+) + Mg2+ and HCO3- exceeded 0.5 because the carbonate rock in Lanhuagou spring and Hougou spring was mainly dissolved by nitric acid and sulfuric acid. Because of the input of litter and the fact that gas-permeability of soil was limited in Baishuwan spring catchment, most of soil CO2 was dissolved in infiltrated water and reacted with bedrock. However, in Lanhuagou spring catchment and Hougou spring catchment, porous soil made soil CO2 easier to return to the atmosphere in the form of soil respiration. Therefore, in order to accurately estimate karst carbon sink, it was required to clarify the distinction of CO2 consumption by carbonate rock dissolution under different land use and land cover areas.

Remote Sensing of Smoke, Land and Clouds from the NASA ER-2 during SAFARI 2000

NASA Technical Reports Server (NTRS)

King, Michael D.; Platnick, Steven; Moeller, Christopher C.; Revercomb, Henry E.; Chu, D. Allen

2002-01-01

The NASA ER-2 aircraft was deployed to southern Africa between August 17 and September 25, 2000 as part of the Southern Africa Regional Science Initiative (SAFARI) 2000. This aircraft carried a sophisticated array of multispectral scanners, multiangle spectroradiometers, a monostatic lidar, a gas correlation radiometer, upward and downward spectral flux radiometers, and two metric mapping cameras. These observations were obtained over a 3200 x 2800 km region of savanna, woody savanna, open shrubland, and grassland ecosystems throughout southern Africa, and were quite often coordinated with overflights by NASA's Terra and Landsat 7 satellites. The primary purpose of this sophisticated high altitude observing platform was to obtain independent observations of smoke, clouds, and land surfaces that could be used to check the validity of various remote sensing measurements derived by Earth-orbiting satellites. These include such things as the accuracy of the Moderate Resolution Imaging Spectro-radiometer (MODIS) cloud mask for distinguishing clouds and heavy aerosol from land and ocean surfaces, and Terra analyses of cloud optical and micro-physical properties, aerosol properties, leaf area index, vegetation index, fire occurrence, carbon monoxide, and surface radiation budget. In addition to coordination with Terra and Landsat 7 satellites, numerous flights were conducted over surface AERONET sites, flux towers in South Africa, Botswana, and Zambia, and in situ aircraft from the University of Washington, South Africa, and the United Kingdom.

River recharge sources and the partitioning of catchment evapotranspiration fluxes as revealed by stable isotope signals in a typical high-elevation arid catchment

NASA Astrophysics Data System (ADS)

Guo, Xiaoyu; Tian, Lide; Wang, Lei; Yu, Wusheng; Qu, Dongmei

2017-06-01

Catchment-scale hydrological cycles are expected to suffer more extremes under a background of climate change. Quantifying hydrological changes in high and remote areas is practically challenging. However, stable isotopes in river water can be seen to vary, dependent upon the combined influence exerted by recharge sources and local climatic conditions; the study of river water stable isotopes can therefore provide a meaningful method for delineating catchment-scale hydrological studies. In this study, we present high-resolution time series of river δ18O and d-excess values; additionally, we identify the seasonal dynamics of river recharge sources and major components of the catchment-scale water balance, together with precipitation and groundwater isotopes, and concurrent meteorological data recorded in Magazangbu catchment on the northwestern Tibetan Plateau (TP). Using isotopic analysis, and within a proportional framework, we partitioned the isotopic fractionation (E1) or non-fractionation (E2) from soil evaporation fluxes (Esoil) apparent in different processes, using NDVI (Normal Differential Vegetation Index) data collected by MODIS satellites to calculate the vegetation fractional coverage (VFC), and Global Land Data Assimilation System (GLDAS) records to determine evapotranspiration data (ET). Finally, the contributions made by each ET component (Esoil and plant transpiration) to total catchment ET were computed for the high and remote northwestern TP. Our results show that: (1) river δ18O values were high in summer and low in winter, while d-excess values displayed a contrary seasonal cycle; (2) for the monsoon period, precipitation contributed 60.6% to Magazangbu catchment runoff. Deeper groundwater was the main water source for the winter low base flow, and shallow groundwater or high elevation snowmelt was the principal component of the spring thaw and autumn freezing periods; and (3) a substantial proportion of Esoil (96.4% annually; 92.2% during

Holding Water in the Landscape; striking a balance between food production and healthy catchment function

NASA Astrophysics Data System (ADS)

Quinn, Paul; Wilkinson, Mark; Stutter, Marc; Adams, Russell

2015-04-01

Here it is proposed that ~5 % of the rural landscape could be modified to hold water during storm events. Hence ~95% of land remains for food production, commercial forestry and amenity. This is a catchment scale commitment to sustainably reducing flood and drought risk, improving water quality, biodiversity and thereby climate proofing our catchments. The farmed landscape has intensified and as a result, runoff rates are no longer in balance with the catchment needs, which in turn contributes to floods, droughts and water pollution problems. The loss of infiltration rates, soil water holding capacity and the increase in ditches and drains through intense farming has resulted in a reduction of the overall water holding capacity of the landscape, therefore deeper soil and aquifer recharge rates are lower. However, adequate raw water supply and food production is also vital. Here we consider how ~5% of productive land could be used to physically hold water during and after storms. This is a simple philosophy for water stewardship that could be delivered by farmers and land managers themselves. In this poster we consider a 'treatment train' of mitigation in headwaters by the construction of:- Rural SuDs - by creating swales, bunds and grassy filters; Buffer Strips - (designed to hold water); The Ditch of The Future - by creating the prime location for holding water and recovering lost top soil and finally the better use of Small Headwater Floodplains - by storing flood water, creating wetlands, planting new forest, installing woody debris and new habitats. We present examples of where and how these measures have been installed and show the cost-effectiveness of temporarily holding storm runoff in several case study catchments taken from the UK.

Projected impacts of urbanisation on hydrological resource flows: A case study within the uMngeni Catchment, South Africa.

PubMed

Schütte, S; Schulze, R E

2017-07-01

Significant land use changes from natural/agricultural to urban land uses have been proposed within the Mpushini/Mkhondeni sub-catchments of the uMngeni Catchment in South Africa. A better understanding of the influences which such land use changes are likely to have on hydrological flows, is required, in order to make informed land use decisions for a sustainable future. As a point of departure, an overview of linkages between urbanisation and hydrological flow responses within this sub-humid study area is given. The urban characteristics of increased impervious areas and the potential return flows from transfers of potable water from outside the catchment were identified as being important in regard to hydrological flow responses. A methodology was developed to model urban response scenarios with urban characteristics as variables, using the daily time-step process based ACRU model. This is a hydrological multi-process model and not an urban hydraulic model and it addresses the landscape as well as the channel components of a catchment, and in addition to runoff components includes evaporation and transpiration losses as outputs. For the study area strong links between proposed urbanisation and hydrological resource flow responses were found, with increases in stormflows, together with increased and more regulated baseflows, and with impacts varying markedly between dry or wet years and by season. The impacts will depend on the fractions of impervious areas, whether or not these are connected to permeable areas, the amount of imported water and water system leaks. Furthermore, the urban hydrological impacts were found to be relatively greater in more arid than humid areas because of changes in the rainfall to runoff conversion. Flow changes due to urbanisation are considered to have important environmental impacts, requiring mitigation. The methodology used in this paper could be used for other urbanising areas. Copyright © 2017 Elsevier Ltd. All rights reserved.

Chemical fractionation of lake sediments to determine the effects of land-use change on nutrient loading

NASA Astrophysics Data System (ADS)

Heathwaite, A. L.

1994-07-01

Lake studies allow contemporary sediment and nutrient dynamics to be placed in a historical context in order that trends and rates of change in catchment inputs may be calculated. Here, a synthesis of the temporal information contained in catchment and lake sediment records is attempted. A chemical fractionation technique is used to isolate the different sediment sources contained in the lake core, and 210Pb dates provide an accurate record of changes in lake sediment sources over the past 100 years. The extent to which land-use records, collated from agricultural census returns, and process-based studies of sediment and nutrient export from different catchment land uses can be used to explain the trends observed in the lake sediments is examined. Sediment influx to the study lake has increased from less than 2 mm year -1 prior to the Second World War to over 10 mm year -1 at present. The source of the sediment is largely unaltered and unweathered allochthonous material eroded from the catchment. Land-use records suggest that the intensification of agriculture, characterized by a shift towards arable land immediately postwar, followed by an increase in the area of temporary grass in the 1960s, may be the cause of accelerated catchment erosion; both land-use changes would have increased the area of ploughed land in the catchment. An increase in the number of cattle and sheep in the catchment from around 2000 and 6000, respectively, in the 1940s, to a peak of nearly 7000 cattle and over 15 000 sheep in the 1980s, provides a further source of sediment and nutrients. Livestock are grazed on permanent grassland which is commonly located on steep hillslopes and in riparian zones where saturation-excess surface runoff may be an important hydrological pathway. Rainfall simulation experiments show that surface runoff from heavily grazed grassland has a high suspended sediment, ammonium-nitrogen and particulate phosphorus load. The combined effect of the long-term increase

Community managed forests dominate the catchment sediment cascade in the mid-hills of Nepal: A compound-specific stable isotope analysis.

PubMed

Upadhayay, Hari Ram; Smith, Hugh G; Griepentrog, Marco; Bodé, Samuel; Bajracharya, Roshan Man; Blake, William; Cornelis, Wim; Boeckx, Pascal

2018-05-08

Soil erosion by water is critical for soil, lake and reservoir degradation in the mid-hills of Nepal. Identification of the nature and relative contribution of sediment sources in rivers is important to mitigate water erosion within catchments and siltation problems in lakes and reservoirs. We estimated the relative contribution of land uses (i.e. sources) to suspended and streambed sediments in the Chitlang catchment using stable carbon isotope signature (δ 13 C) of long-chain fatty acids as a tracer input for MixSIAR, a Bayesian mixing model used to apportion sediment sources. Our findings reveal that the relative contribution of land uses varied between suspended and streambed sediment, but did not change over the monsoon period. Significant over- or under-prediction of source contributions could occur due to overlapping source tracer values, if source groups are classified on a catchment-wide basis. Therefore, we applied a novel deconvolutional framework of MixSIAR (D-MixSIAR) to improve source apportionment of suspended sediment collected at tributary confluences (i.e. sub-catchment level) and at the outlet of the entire catchment. The results indicated that the mixed forest was the dominant (41 ± 13%) contributor of sediment followed by broadleaf forest (15 ± 8%) at the catchment outlet during the pre-wet season, suggesting that forest disturbance as well as high rainfall and steep slopes interact for high sediment generation within the study catchment. Unpaved rural road tracks located on flat and steep slopes (11 ± 8 and 9 ± 7% respectively) almost equally contributed to the sediment. Importantly, agricultural terraces (upland and lowland) had minimal contribution (each <7%) confirming that proper terrace management and traditional irrigation systems played an important role in mitigating sediment generation and delivery. Source contributions had a small temporal, but large spatial, variation in the sediment cascade of Chitlang stream

Importance of land use update during the calibration period and simulation of water balance response to land use change in the upper Rio das Mortes Catchment (Cerrado Biome, Central-Western Brazil)

NASA Astrophysics Data System (ADS)

Lamparter, Gabriele; Kovacs, Kristof; Nobrega, Rodolfo; Gerold, Gerhard

2015-04-01

Changes in the hydrological balance and following degradation of the water ecosystem services due to large scale land use changes are reported from agricultural frontiers all over the world. Traditionally, hydrological models including vegetation and land use as a part of the hydrological cycle use a fixed distribution of land use for the calibration period. We believe that a meaningful calibration - especially when investigating the effects of land use change on hydrology - demands the inclusion of land use change during the calibration period into the calibration procedure. The SWAT (Soil and Water Assessment Tool) model is a process-based, semi-distributed model calculating the different components of the water balance. The model bases on the definition of hydrological response units (HRUs) which are based on soil, vegetation and slope distribution. It specifically emphasises the role of land use and land management on the water balance. The Central-Western region of Brazil is one of the leading agricultural frontiers, which experienced rapid and radical deforestation and agricultural intensification in the last 40 years (from natural Cerrado savannah to cattle grazing to intensive corn and soya cropland). The land use history of the upper Rio das Mortes catchment (with 17500 km²) is reasonably well documented since the 1970th. At the same time there are almost continuous climate and runoff data available for the period between 1988 and 2011. Therefore, the work presented here shows the model calibration and validation of the SWAT model with the land use update function for three different periods (1988 to 1998, 1998 to 2007 and 2007 to 2011) in comparison with the same calibration periods using a steady state land use distribution. The use of the land use update function allows a clearer identification which changes in the discharge are due to climatic variability and which are due to changes in the vegetation cover. With land use update included into the

Establishing an Integrated Catchment Management (ICM) program in East Java, Indonesia.

PubMed

Booth, C A; Warianti, A; Wrigley, T

2001-01-01

The Brantas is one of Indonesia's most important catchments. It is the "rice bowl" of Java and nationally important for its industrial activity. Surabaya, Indonesia's second largest city, is located at the mouth of the Brantas River which is pivotal to the city's water supply. The challenges associated with the institutional framework for natural resource management in East Java parallels that of many states and provinces around the globe. It is multi-layered and complex. Integrated Catchment Management (ICM) may be defined as "the co-ordinated and sustainable management of land, water, soil vegetation, fauna and other natural resources on a water catchment basis". Over a period of six months, an ICM Strategy was researched and facilitated for the Brantas River Catchment in East Java via a short term advisor attachment. The aim of the Strategy is to improve coordination, co-operation, communication and consistency of government and community efforts towards sustaining the catchment's environmental, economic and social values. The attachment was part of the Pollution Control Implementation (PCI) Project funded by AusAid and the Indonesian Government. The ICM Strategy developed was broad based and addressed the priority natural resource management issues facing the Brantas Catchment. It was co-ordinated by BAPEDALDA, the Provincial Environmental Protection Agency, and developed by all agencies involved in natural resource management in the catchment. Various Universities and Non Government Organisations (NGOs) were also involved in the ICM process which developed the Strategy. At the conclusion of the attachment, a draft ICM Strategy and a proposed institutional framework had been developed. A working group of key agencies was also established to further enhance local "ownership", finalise timescales and implementation responsibilities within the Strategy and bring the institutional arrangements into being through a Governor's Decree.

RNICO: a new simple geometric index for assessing the impact of urban development pattern on peak flows in urban catchments

NASA Astrophysics Data System (ADS)

Kasaee Roodsari, B.; Chandler, D. G.

2016-12-01

Urban sprawl is widespread across the world and the associated hydrologic impacts are increasing in peri-urban catchments due to increased area of impervious. There is a strong agreement on the positive correlation between the fractional impervious area and peak flows in urban catchments. Nevertheless, the effect of land development pattern on peak flows is not well investigated. In this study, a new simple geometric index, Relative Nearness of Imperviousness to the Catchment Outlet (RNICO), is defined to correlate imperviousness distribution of peri-urban catchments to runoff peak flows. Results of applying RNICO to 20 sub-catchments in New York State showed a strong positive correlation (R2>0.97) between RNICO and runoff peak flows for small peri-urban catchments (A< 42 km2) indicating higher flood risk of downstream urbanization. For large catchments (A> 42 km2), no correlation was indicated between RNICO and peak flows. We highlight the necessity of a greater discharge monitoring network at small peri-urban catchments to support local urban flood forecast.

Catchment-scale environmental controls of sediment-associated contaminant dispersal

NASA Astrophysics Data System (ADS)

Macklin, Mark

2010-05-01

Globally river sediment associated contaminants, most notably heavy metals, radionuclides, Polychlorinated Biphenyls (PCBs), Organochlorine pesticides (OCs) and phosphorous, constitute one the most significant long-term risks to ecosystems and human health. These can impact both urban and rural areas and, because of their prolonged environmental residence times, are major sources of secondary pollution if contaminated soil and sediment are disturbed by human activity or by natural processes such as water or wind erosion. River catchments are also the primary source of sediment-associated contaminants to the coastal zone, and to the ocean, and an understanding of the factors that control contaminated sediment fluxes and delivery in river systems is essential for effective environmental management and protection. In this paper the catchment-scale controls of sediment-associated contaminant dispersal are reviewed, including climate-related variations in flooding regime, land-use change, channel engineering, restoration and flood defence. Drawing on case studies from metal mining impacted catchments in Bolivia (Río Pilcomayo), Spain (Río Guadiamar), Romania (River Tisa) and the UK (River Swale) some improved methodologies for identifying, tracing, modelling and managing contaminated river sediments are proposed that could have more general application in similarly affected river systems worldwide.

Catchment systems science and management: from evidence to resilient landscapes

NASA Astrophysics Data System (ADS)

Quinn, Paul

2014-05-01

There is an urgent need to reassess both the scientific understanding and the policy making approaches taken to manage flooding, water scarcity and pollution in intensively utilised catchments. Many European catchments have been heavily modified and natural systems have largely disappeared. However, working with natural processes must still be at the core of any future management strategy. Many catchments have greatly reduced infiltration rates and buffering capacity and this process needs to be reversed. An interventionist and holistic approach to managing water quantity and quality at the catchment scale is urgently required through the active manipulation of natural flow processes. Both quantitative (field experiments and modelling) and qualitative evidence (local knowledge) is required to demonstrate that catchment have become 'unhealthy'. For example, dense networks of low cost instrumentation could provide this multiscale evidence and, coupled with stakeholder knowledge, build a comprehensive understanding of whole system function. Proactive Catchment System Management is an interventionist approach to altering the catchment scale runoff regime through the manipulation of landscape scale hydrological flow pathways. Many of the changes to hydrological processes cannot be detected at the catchment scale as the primary causes of flooding and pollution. Evidence shows it is the land cover and the soil that are paramount to any change. Local evidence shows us that intense agricultural practices reduce the infiltration capacity through soil degradation. The intrinsic buffering capacity has also been lost across the landscape. The emerging hydrological process is one in which the whole system responds too quickly (driven by near surface and overland flow processes). The bulk of the soil matrix is bypassed during storm events and there is little or no buffering capacity in the riparian areas or in headwater catchments. The prospect of lower intensity farming rates is

Landing and Rollout STS-135 Crew Training on the Vertical Motion Simulator (VMS) at NASA Ames (Reporter Pkg)

NASA Image and Video Library

2011-07-05

Every Space Shuttle flight crew has trained for the final phase of a Shuttle mission, landing and rollout, using the VMS at NASA Ames. This story follows at the crew of STS-135, the final Space Shuttle mission, as they train on the VMS. Includes an interview with Chris Ferguson, the STS-135 mission commander.

Multivariate analysis of water quality and environmental variables in the Great Barrier Reef catchments

NASA Astrophysics Data System (ADS)

Ryu, D.; Liu, S.; Western, A. W.; Webb, J. A.; Lintern, A.; Leahy, P.; Wilson, P.; Watson, M.; Waters, D.; Bende-Michl, U.

2016-12-01

The Great Barrier Reef (GBR) lagoon has been experiencing significant water quality deterioration due in part to agricultural intensification and urban settlement in adjacent catchments. The degradation of water quality in rivers is caused by land-derived pollutants (i.e. sediment, nutrient and pesticide). A better understanding of dynamics of water quality is essential for land management to improve the GBR ecosystem. However, water quality is also greatly influenced by natural hydrological processes. To assess influencing factors and predict the water quality accurately, selection of the most important predictors of water quality is necessary. In this work, multivariate statistical techniques - cluster analysis (CA), principal component analysis (PCA) and factor analysis (FA) - are used to reduce the complexity derived from the multidimensional water quality monitoring data. Seventeen stations are selected across the GBR catchments, and the event-based measurements of 12 variables monitored during 9 years (2006 - 2014) were analysed by means of CA and PCA/FA. The key findings are: (1) 17 stations can be grouped into two clusters according to the hierarchical CA, and the spatial dissimilarity between these sites is characterised by the different climatic and land use in the GBR catchments. (2) PCA results indicate that the first 3 PCs explain 85% of the total variance, and FA on the entire data set shows that the varifactor (VF) loadings can be used to interpret the sources of spatial variation in water quality on the GBR catchments level. The impact of soil erosion and non-point source of pollutants from agriculture contribution to VF1 and the variability in hydrological conditions and biogeochemical processes can explain the loadings in VF2. (3) FA is also performed on two groups of sites identified in CA individually, to evaluate the underlying sources that are responsible for spatial variability in water quality in the two groups. For the Cluster 1 sites

A bottom up approach for engineering catchments through sustainable runoff management

NASA Astrophysics Data System (ADS)

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

2010-12-01

There is no doubt that our catchments are under great stress. There have been many accounts around the world of severe flood events and water quality issues within channels. As a result of these, ecological habitats in rivers are also under pressure. Within the United Kingdom, all these issues have been identified as key target areas for policy. Traditionally this has been managed by a policy driven top down approach which is usually ineffective. A one ‘size fits all’ attitude often does not work. This paper presents a case study in northern England whereby a bottom up approach is applied to multipurpose managing of catchments at the source (in the order of 1-10km2). This includes simultaneous tackling of water quality, flooding and ecological issues by creating sustainable runoff management solutions such as storage ponds, wetlands, beaver dams and willow riparian features. In order to identify the prevailing issues in a specific catchment, full and transparent stakeholder engagement is essential, with everybody who has a vested interest in the catchment being involved from the beginning. These problems can then be dealt with through the use of a novel catchment management toolkit, which is transferable to similar scale catchments. However, evidence collected on the ground also allows for upscaling of the toolkit. The process gathers the scientific evidence about the effectiveness of existing or new measures, which can really change the catchment functions. Still, we need to get better at communicating the science to policy makers and policy therefore must facilitate a bottom up approach to land and water management. We show a test site for this approach in the Belford burn catchment (6km2), northern England. This catchment has problems with flooding and water quality. Increased sediment loads are affecting the nearby estuary which is an important ecological zone and numerous floods have affected the local village. A catchment engineering toolkit has been

Macroinvertebrate assemblages associated with patterns in land use and water quality

USGS Publications Warehouse

Carlisle, Daren M.; Stewart, Paul M.; Butcher, Jason T.; Simon, Thomas P.

2003-01-01

Most national parks were designated to preserve significant natural resources. Park borders often reflect political rather than ecological boundaries. Consequently, catchments of many streams are only partially within park boundaries, and are therefore subject to land use changes and potential contamination from non-point sources outside the park. The National Park Service has initiated a program to monitor natural resources, particularly those at risk from land use changes surrounding the parks. This effort requires the identification of response signatures indicative of the ecological effects of human activities. The goal of this chapter is to identify a biological response signature (e.g., indicator assemblages) for tributary streams in Cuyahoga Valley National Park. More than 20 first to fourth order tributary streams enter the Cuyahoga River within park boundaries. Many of these catchments are outside park boundaries and under suburban development. The purpose of this research is to provide park managers with a monitoring tool for identifying the extent and degree of aquatic resource degradation due to land use changes in tributary catchments.

The CAMELS data set: catchment attributes and meteorology for large-sample studies

NASA Astrophysics Data System (ADS)

Addor, Nans; Newman, Andrew J.; Mizukami, Naoki; Clark, Martyn P.

2017-10-01

We present a new data set of attributes for 671 catchments in the contiguous United States (CONUS) minimally impacted by human activities. This complements the daily time series of meteorological forcing and streamflow provided by Newman et al. (2015b). To produce this extension, we synthesized diverse and complementary data sets to describe six main classes of attributes at the catchment scale: topography, climate, streamflow, land cover, soil, and geology. The spatial variations among basins over the CONUS are discussed and compared using a series of maps. The large number of catchments, combined with the diversity of the attributes we extracted, makes this new data set well suited for large-sample studies and comparative hydrology. In comparison to the similar Model Parameter Estimation Experiment (MOPEX) data set, this data set relies on more recent data, it covers a wider range of attributes, and its catchments are more evenly distributed across the CONUS. This study also involves assessments of the limitations of the source data sets used to compute catchment attributes, as well as detailed descriptions of how the attributes were computed. The hydrometeorological time series provided by Newman et al. (2015b, https://doi.org/10.5065/D6MW2F4D) together with the catchment attributes introduced in this paper (https://doi.org/10.5065/D6G73C3Q) constitute the freely available CAMELS data set, which stands for Catchment Attributes and MEteorology for Large-sample Studies.

Constraining the JULES land-surface model for different land-use types using citizen-science generated hydrological data

NASA Astrophysics Data System (ADS)

Chou, H. K.; Ochoa-Tocachi, B. F.; Buytaert, W.

2017-12-01

Community land surface models such as JULES are increasingly used for hydrological assessment because of their state-of-the-art representation of land-surface processes. However, a major weakness of JULES and other land surface models is the limited number of land surface parameterizations that is available. Therefore, this study explores the use of data from a network of catchments under homogeneous land-use to generate parameter "libraries" to extent the land surface parameterizations of JULES. The network (called iMHEA) is part of a grassroots initiative to characterise the hydrological response of different Andean ecosystems, and collects data on streamflow, precipitation, and several weather variables at a high temporal resolution. The tropical Andes are a useful case study because of the complexity of meteorological and geographical conditions combined with extremely heterogeneous land-use that result in a wide range of hydrological responses. We then calibrated JULES for each land-use represented in the iMHEA dataset. For the individual land-use types, the results show improved simulations of streamflow when using the calibrated parameters with respect to default values. In particular, the partitioning between surface and subsurface flows can be improved. But also, on a regional scale, hydrological modelling was greatly benefitted from constraining parameters using such distributed citizen-science generated streamflow data. This study demonstrates the modelling and prediction on regional hydrology by integrating citizen science and land surface model. In the context of hydrological study, the limitation of data scarcity could be solved indeed by using this framework. Improved predictions of such impacts could be leveraged by catchment managers to guide watershed interventions, to evaluate their effectiveness, and to minimize risks.

Using high-resolution phosphorus data to investigate mitigation measures in headwater river catchments

NASA Astrophysics Data System (ADS)

Campbell, J. M.; Jordan, P.; Arnscheidt, J.

2015-01-01

This study reports the use of high-resolution water quality monitoring to assess the influence of changes in land use management on total phosphorus (TP) transfers in two 5 km2 agricultural sub-catchments. Specifically, the work investigates the issue of agricultural soil P management and subsequent diffuse transfers at high river flows over a 5-year timescale. The work also investigates the phenomenon of low flow P pollution from septic tank systems (STSs) and mitigation efforts - a key concern for catchment management. Results showed an inconsistent response to soil P management over 5 years with one catchment showing a convergence to optimum P concentrations and the other an overall increase. Both catchments indicated an overall increase in P concentration in defined high flow ranges. Low flow P concentration showed little change or higher P concentrations in defined low flow ranges despite replacement of defective systems and this is possibly due to a number of confounding reasons including increased housing densities due to new-builds. The work indicates fractured responses to catchment management advice and mitigation and that the short to medium term may be an insufficient time to expect the full implementation of policies (here defined as convergence to optimum soil P concentration and mitigation of STSs) and also to gauge their effectiveness.

The road to NHDPlus — Advancements in digital stream networks and associated catchments

USGS Publications Warehouse

Moore, Richard B.; Dewald, Thomas A.

2016-01-01

A progression of advancements in Geographic Information Systems techniques for hydrologic network and associated catchment delineation has led to the production of the National Hydrography Dataset Plus (NHDPlus). NHDPlus is a digital stream network for hydrologic modeling with catchments and a suite of related geospatial data. Digital stream networks with associated catchments provide a geospatial framework for linking and integrating water-related data. Advancements in the development of NHDPlus are expected to continue to improve the capabilities of this national geospatial hydrologic framework. NHDPlus is built upon the medium-resolution NHD and, like NHD, was developed by the U.S. Environmental Protection Agency and U.S. Geological Survey to support the estimation of streamflow and stream velocity used in fate-and-transport modeling. Catchments included with NHDPlus were created by integrating vector information from the NHD and from the Watershed Boundary Dataset with the gridded land surface elevation as represented by the National Elevation Dataset. NHDPlus is an actively used and continually improved dataset. Users recognize the importance of a reliable stream network and associated catchments. The NHDPlus spatial features and associated data tables will continue to be improved to support regional water quality and streamflow models and other user-defined applications.