Quickbird satellite imagery for riparian management : characterizing riparian filter strips and detecting concentrated flow in an agricultural watershed

Riparian ecology plays an important part in the filtration of sediments from upland agricultural lands. The focus of this work makes use of multispectral high spatial resolution remote sensing imagery (Quickbird by Digital Globe) and geographic information systems (GIS) to characterize significant riparian attributes in the USDA’s experimental watershed, Goodwin Creek, located in northern Mississippi. Significant riparian filter characteristics include the width of the strip, vegetation properties, soil properties, topography, and upland land use practices. The land use and vegetation classes are extracted from the remotely sensed image with a supervised maximum likelihood classification algorithm. Accuracy assessments resulted in an acceptable overall accuracy of 84 percent. In addition to sensing riparian vegetation characteristics, this work addresses the issue of concentrated flow bypassing a riparian filter. Results indicate that Quickbird multispectral remote sensing and GIS data are capable of determining riparian impact on filtering sediment. Quickbird imagery is a practical solution for land managers to monitor the effectiveness of riparian filtration in an agricultural watershed

Water Quality, Modeling, And Land Use Investigations In The Upper Pearl River Basin Of East-Central Mississippi

Little historical water quality data is available for the Upper Pearl River Basin (UPRB), yet there are UPRB waters listed as impaired. Objectives of this research were to measure pesticide and sediment concentrations in UPRB surface waters and validate the Annualized Agricultural Nonpoint-Source (AnnAGNPS) runoff model with the measured data for a portion of the UPRB. An additional objective was to quantify effects of land use changes on UPRB surface waters from 1987 to 2002 using AnnAGNPS. Of the fifteen compounds analyzed, hexazinone was most frequently detected, in 94% of samples, followed by metolachlor, tebuthiuron, and atrazine. Metribuzin was detected in only 6% of samples. Total dissolved solids (TDS) concentrations were highest at Carthage, which drains the largest area of three sites sampled for TDS. Most samples measured below Environmental Protection Agency (EPA) standards for pesticides and TDS in drinking water and also below levels toxic to aquatic organisms. For eight of twelve months analyzed between October 2001 and January 2003, average monthly sediment loadings for measured and AnnAGNPS-simulated data differed no more than 109%, resulting in an R&178; value of 0.328. A comparison of measured and simulated atrazine and metolachlor loadings by event resulted in R&178; values of 0.095 and 0.062, respectively. Most daily atrazine and metolachlor loadings for measured and predicted data were very low. On May 18, 2003, AnnAGNPS predicted a metolachlor loading of 80 mg, while measured data showed a loading of 5.6 mg. Measured data showed an earlier spike on January 20, 2003 that was not mirrored by the model. Atrazine comparisons followed the same trend, except measured loadings did not spike until February 22, 2003. The 2002 AnnAGNPS simulation resulted in 15% more average annual runoff than the 1987 simulation, although both simulations had the same precipitation. The 2002 simulation also had higher values for sediment and organic carbon loading. Nitrogen loading was the only runoff or pollutant loading category that was less for 2002 than for 1987. Urban land cover contributed more runoff and pollutant loadings from 1987 to 2002, while traditional row crop agriculture had less of an impact on pollutant loadings

Validation of AnnAGNPS at the field and farm-scale using an integrated AGNPS/GIS system

Non-Point Source (NPS) pollution models are effective watershed-scale predictors of NPS loadings and useful evaluators of agricultural Best Management Practices (BMPs) and water quality Total Maximum Daily Loads (TMDLs). The work reported in this thesis examined two applications of the AGricultural Non-Point-Source (AGNPS) pollution model: 1) predicting surface runoff, nutrient loading, and sediment yield predictions for an artificially delineated farm-scale watershed; and 2) evaluating relative benefits of different BMPs on reducing sediment accumulation in a lake surrounded by agricultural land. A procedure using identification, extraction, and processing of critical area data using an ArcView Geographic Information System (GIS) was used in both applications. In the first, 30 years of synthetic climate data were used to generate event and source accounting predictions for a multi-use 600-acre research farm in South Louisiana. Runoff water quality predictions for hydrologic cells in standard and artificially delineated watershed simulations were compared. Estimates for sediment, N and P loading in paired watershed cells agreed well, indicating that an integrated AGNPS/GIS system can reliably simulate runoff and NPS loadings for artificially delineated watersheds. Thus, successful implementation of AGNPS for an extracted small-scale region eliminated processing extraneous data, hence reducing simulation time and work required. This approach could allow land operators to initiate and/or evaluate nutrient and site management plans. The second application used AGNPS to evaluate benefits of different BMPs on reducing sedimentation in a small lake. Extensive land clearing in the 1970s for row crop production in Avoyelles Parish accelerated sediment deposition in local waterbodies. Data for depth of the original bottom of an approximately 2 ha lake below recent (\u3c 30 years) sediment estimated from 137Cs, Pb, clay and organic matter profiles), and sediment bulk density and texture were used to calibrate the AGNPS water quality model for representative hydrologic cells discharging into this lake. Upland erosion and sediment discharge rates predicted under alternative, conservation management practices indicate that sediment accumulation in this lake could have been substantially reduced

Impact of temporal changes of land use on surface Run-off A case study on musi basin using soil and water assessment tool (SWAT)

Land and water are the two most vital natural resources of the world. Proper planning and management of these two most vital natural resources is, therefore, of utmost necessity. For proper planning and efficient utilization of the land and water resources it is necessary to understand the hydrological cycle and estimate the hydrological parameters. In the present study SWAT2012 (Soil and Water Assessment Tool, ArcSWAT10.2.2), a physical based semi distributed hydrologic model having an interface with ArcGIS 10.2.2, GIS software was applied for Musi Basin, a sub-basin of river Krishna, covering an area of 11268.54 sq.km in order to model the various hydrological components and to assess the impact of land use/land cover on the surface flow. In order to study the impact of land use/land cover on surface runoff, simulations were carried out for the crop periods of kharif 2005-06 and kharif 2010-11 using the same precipitation file. Results indicated that with an increase in irrigated land and increase in urban land, during the period from 2005 to 2010 surface runoff has increased by 8.47mm (18.6% to 19.6% of precipitation) showing that the land use/land cover has an impact on the hydrological regime. Then the simulations were carried out for the land use of 2005-06 kharif with and without irrigation operation for a time period of 35 years (1979-2013) and the simulations showed that the surface runoff was more for the model under irrigation by 7.6%. Runoff had increased from 24.8% to 32.4 % of precipitation. These results clearly show how land use changes and agricultural management practices impact hydrological parameters like runoff

A mathematical model development for simulating in-stream processes of non-point source pollutants.

Doctoral Degree. University of KwaZulu-Natal, Durban.In coming years, chronic water stress is inevitable owing to the unavailability of fresh water. This situation is occasioned by rapid urbanisation, climate change, rising food demand, and production. The increasing rate of water scarcity associated with water pollution problems, makes water quality management an issue of great concern. Rivers owe their existence to the relationship of rainfalls, soil properties and land use within a catchment. The entire hydrological processes that occur in the catchment area has a direct effect on occurrences and quality of the rivers there-in. A principal part of the hydrological cycle is runoff generation. Runoff characterises soil erosion, sediment transport, pollutants and chemicals all otherwise referred to as non-point source pollutants and released into water bodies. Most non-point source pollutants are generated from agricultural fields, informal settlements, mining fields, industrial areas, and roads. These sources produce increased nutrient concentrates (sewage effluent from informal settlements and fertilisers from agricultural fields) and toxic substances which alter the water quality in uncertain quantities. This affects aquatic biota and ultimately human health negatively. Non-point source pollution is a major source of water quality degradation globally and is the single most significant threat to subsurface and surface sources of usable water. Developed countries, unlike many developing countries, have long sought ways to stop the release of non-point source pollution directly into natural rivers through the establishment of best management practices but unfortunately with little success in actual practice. Numerous non-point source models exist which are basically watershed based and are limited to simulate the in-stream processes of non-point source pollution in water channels. Most existing non-point source models are site-specific, cumbersome to manipulate, need high-level operational skills and extensive data sets. Consequently, these models are difficult to use in areas apart from where they were developed and with limited data sets, as is the case with developing countries. Hence, to develop a non-point source pollution model that would adequately and effectively, simulate non-point source pollution in water bodies, towards restoring good river health is needed. This is required to enhance the proper monitoring and remediation of water sources affected by Non-Point Source Pollution especially in areas that have scarce data. Using the concept of the Hybrid Cells in Series model in this study, a hydrodynamic riverine Non-point source pollution model is conceptualized to simulate conservative pollutants in natural rivers. The Hybrid Cells in Series model was conceptualized to address the limitations identified in the classical advection dispersion model which is the foundation for all water quality modelling. The proposed model is a three-parameter model made up of three zones, which describes pure advection through time delay in a plug zone, and advection and dispersion occurring in two other thoroughly mixed zones linked in sequence. The model considers lateral inflow and pollutant loading along the river reach in addition to the point source pollutant entry and flow from upstream stations. The model equation for water quality along with hydrodynamic equation has been solved analytically using Laplace Transform. The derived mathematical formulation is appropriately coded, using FORTRAN programming language. Other components such as hyporheic exchange process and first order kinetic reaction simulations are incorporated to the proposed model. The response of these models matches the numerical solution of the classical Advection Dispersion Equation model satisfactorily when compared. The potential of the proposed model is tested using field data obtained from verifiable existing literature. A performance evaluation at 95 percent confidence is carried out. The correlation results of the observed and simulated data are seen to be in good agreement. The breakthrough curves obtained from the proposed model shows its capability to simulate Non-point source pollution transport in natural rivers effectively. The simplicity of the Hybrid Cells in Series model makes it a viable model for simulating contaminant transport from non-point sources. As the model has been validated using recorded data collected from the field for a specific tracer injection event, it is imperative to carry out investigation on changes in model parameters before, during and after storm events. However, this study adequately addressed and attempted to develop, validate new model components for simulating non-point source pollutant transport processes in stream

Sediment TMDL calculations for Amite River

The Amite River is recognized as one of the 15 water bodies impaired by sediments in Louisiana. A sediment TMDL calculation for the Amite River is required by the EPA. Based on EPA’s Protocol sediment TMDL calculations for the Upper Amite River are conducted in this thesis. The sediment TMDL calculations are composed of four parts: (1) Development of a new sediment transport and dispersion model for the Amite River, (2) Estimation of sediment loads (sources) produced by watershed erosion, (3) Flow computation, and (4) Determination of sediment TMDL for the Amite River. Using the mass conservation principle and Reynolds transport theorem a new model has been developed for computation of sediment transport in the Amite River. Sediment erosion in the Amite River Basin is calculated by combining the USLE (Universal Soil Loss Equation) model with GIS and the digital elevation model of the Amite River Basin. Digital elevation data was imported into the GIS. The calculated soil erosion rate for the Upper Amite River Basin is 5.42 ton/acre/year, producing sediment load of 0.103 kg/ to the Amite River. The flow computation is performed under steady and unsteady flow conditions using the HEC-RAS software developed by the U.S.Army Corps of Engineers. Under the steady flow condition the computed sediment concentration varies in the range of 3-114mg/L. The numeric target criterion was not to exceed 50 NTU or 64 mg/L of suspended sediment. Based on this criterion and the new model developed in the thesis, the sediment TMDL calculations were conducted for steady and unsteady flow. It is found that there is significant difference between TMDLs for steady and unsteady flow due to high sediment loads produced by unsteady flow. It is recommended that (1) sediment TMDL calculation need to take account of the influence of unsteady flow; (2) Sediment criteria for the Amite River can be met by adopting practices such as terraces on the steep slopes, creation of buffer zones along the river. Results indicate that the new model can be an effective tool for sediment TMDL calculations

Modelling of pollutant distribution in surface runoff in ungauged catchments using geographical information systems

In developing countries the scarcity of environmental information poses a difficult problem to the planner who is interested in assessing different control strategies for water quality problems. Although sophisticated models exist, the data available to run such models is usually limited. Furthermore, few of the models are easy to use, can operate over a variety of conditions, and can integrate the wide range of data that planners and managers need to compare water quality control strategies. The aim of this thesis has been to develop a water quality model, suitable for Brazilian conditions and that is capable of estimating the effects of future land use scenarios on water quality. The model is designed to be consistent with the availability of data in less developed countries and one of its major advantages is that the parameters involved are easily defined in terms of physical characteristics alone. A methodology is presented which has been designed specifically to support the determination of water quality changes resulting from point and non-point sources in a large river basin with varied land use, taking into account both the magnitude and spatial distribution of the loads produced. The methodology is capable of implementation on land surfaces having heterogeneous distribution of water pollution sources. The model is based on a cellular configuration where information on land use, topography, soil type and rainfall is manipulated using geographical information systems (GIS). Information on land use in each cell is obtained by classifying remotely sensed satellite data. Topographic parameters for each cell are derived from digital elevation models (DEM). Rainfall values for each cell are obtained from the interpolation of point data derived from meteorological stations. Other more conventional data are acquired by digiti sing maps. Using this cellular structure, runoff, and chemical outputs from the individual cell, are routed through the catchment using a physically based mixing model to provide input to the drainage network. The network, derived automatically from a digital elevation model (DEM), defines the river system in the model. The link between the catchment and the river network defines a river 'buffer' zone where point and non-point sources are stored. The model enables spatial relationships between point and non-point sources to be investigated and the consequences to the river system can then be modelled using the river network topology. The model is demonstrated for the Sinos catchment in southern Brazil. Analysis of the case study results indicate the model is capable of generating reasonable trends in water quality which reflect the impact of management activities. However, only limited water quality data availability precludes exhaustive testing of the system, and further work in this area is needed. The use of the model to investigate future water quality scenarios is also illustrated. Finally, the propagation of errors (due to spatial variation) associated with input variables is investigated. The problem is examined by first order theory and stochastic modelling, combined with the physical models, to show the possible magnitude of error within the model predictions

GIS analysis of cropping systems: proceedings of an International Workshop on Harmonization of Databases for GIS Analysis of Cropping Systems in the Asia Region,18-19 Aug 1997, ICRISAT-Patancheru, India

Geographic information systems (GIS) have come a long way from obscurity in the 1980s to now become commonplace in universities, international research institutions, government departments, and private businesses where the technology is used for a wide range of applications. In the last few years, its application has been increasing in agricultural research and development. The International Workshop on Harmonization of Databases for GI S Analysis of Cropping Systems in the Asia Region, held 18-19 Aug 1997 at ICRISAT, Patancheru, India examined the current status of available software options, database requirements, availability of data, database storage and exchange procedures, options for GI S outputs and optimization of regional interactions in the use of GI S for cropping system analysis wi t h respect to Asia. GI S specialists from international agricultural research centers (IARCs) and national agricultural research systems (NARS) of Asia reviewed state-of-the-art know-how in using GI S as a research tool for the characterization of target environments, soil, water and nutrient management, integrated pest and disease management, and sustainable land-use systems. The workshop focussed on three basic questions: "what information is available?", "in what form is the information available?", and "in what form should the GI S output be?" Recommendations were made on the effective use of GI S and on the possibility of harmonizing datasets for common use by IARCs and NARS. The workshop was followed by a hands-on training program on the use of GI S in analysis of cropping systems of Bangladesh, India, Nepal, Pakistan, and Sri Lanka. The country case studies prepared during this training program wi l l be published as a separate volume. The present publication includes status papers describing GI S as a research tool, types of GI S software available and its use in different institutions