in the present study, the soil and water assessment tool (swat 2000) model was tested on both a monthly and yearly basis and applied to the kordan watershed, located in iran. the main objective of the research was to assess the accuracy of the model in sediment-yield and surface water bicarbonate concentration estimation. the attributes of sub-watersheds, tributary channels and the main channel...

river flow forecasting for a region has a special and important role for optimal allocation of water resources. in this research, for forecasting river flow process, fuzzy inference system (fis) is used. three parameters including precipitation, temperature and daily discharge are used for forecasting of daily river flow of lighvan river located in lighvanchai watershed. for the initial preproc...

The article proposes a model for integrated management of a regulated watershed. In such systems, it is important to take into account not only the discharge released at the reservoir, but also the natural flows due to rainfall. The proposed model incorporates both inputs, and can be refined by considering different numbers of sub-basins corresponding to tributaries of the river. We discuss the...

This report evaluates and demonstrates technical methods of comparing point source (PS) and non-point source (NPS) nutrient discharges that can be used for developing credit scoring methods for a water quality trading system. We evaluate the state of the science for evaluating hydrologic functions within watersheds and for linking those physical functions to water quality and environmental outc...

Triangulated surfaces are often used to represent terrains in geographic information systems. We investigate the complexity of river networks and watershed maps on such terrains under the assumption that water always follows the path of steepest descent. We show that the worst-case complexity is only Θ(n) if all triangles are non-obtuse or if all triangles are fat, that is, their minimum angles...

Preservation of extraordinary natural resources, protection of water quality, and restoration of impaired waters require a strategy to identify and protect least-disturbed streams and rivers. We applied two objective, quantitative methods to determine stream ecological integrity of headwater reaches of 10 Ozark rivers, 5 with Wild and Scenic River federal protective status. Thirty-four variable...

The Sinos River Basin is often mentioned as a highly degraded watershed. A series of impacts on water quality, soil and air has been reported in this environment on a recurring basis over the years. This situation of environmental degradation has its origins in a process of huge economic development uncoupled from environmental conservation concerns. The intense consequent urbanization observed...

A sampling program was conducted to assess the quality of runoff associated with a variety of land uses in the Tijuana River watershed, a binational river basin on the U.S. Mexican border. Generally, metal concentrations in samples collected during the first two to four hours of runoff (early storm) were higher than those in samples collected 24 36 hours into the rain event (late storm). A nota...

Water quality in mountain streams of the southern Appalachians varies seasonally and with storms. In an effort to validate Total Maximum Daily Loads (TMDLs) for sediment in the Chattooga River Watershed (NE Georgia, NW South Carolina, and SW North Carolina), we studied four tributary streams over an eighteen-month period. Two of the streams had completely forested watersheds; one stream was a b...

The main goal of this study is to use "top-down"? approach to simulate catchment scale hydrologic processes, in terms of water partitioning, runoff generation, storage dynamics and human/water interaction, and therefore to obtain a comprehensive understanding on intra-annual water balance of watersheds. An evaporation model at seasonal scale is developed based on Budyko framework. A runoff gene...