A GIS Assessment of Non- Point Source Pollution Modelling in the Timber Creek Watershed, Cooke County, Texas, USA

In order to improve water quality and restore impaired watersheds, managers need to make decisions using data that are readily available. Due to limited resources as a result of the cost implications of data, modelling approach is considered. The Universal Soil Loss Equation (USLE) is a Geographic Information System (GIS)-based methodology commonly used to estimate sediment yield. The model is appropriate for predicting soil erosion if data and methodical processes involve GIS. However it is not be considered as a final and true depiction to predict erosion. A good understanding of the watershed is needed to validate the model outputs. The model implementation is relatively cheap, cost effective and easy. Existing data and freely available information in the public domain are used for computations. For this study the total sediment in the watershed showed a 48.5% and 60 % difference when the results were compared with the studies of Levine et al., 1993 and UNITAR, 2009. The results may not be devoid of uncertainties and errors due to data sources and implementation of the model parameters. Keywords: sediment yield, watershed, GIS, soil erosion, USLE, modellin