This paper discusses the development of an analytical support system for implementation of the Integrated Water Resources Management (IWRM) process. The system integrates four analytical tools: (i) geographic information system; (ii) system dynamics simulation; (iii) agent-based model; and (iv) hydrologic simulation. The choice of tools is driven by their ability to (a) respond to the main requ...

objective: mashhad metropolis as the second largest religioncity in the world and the second largest metropolis of iran with an annual 3 million pilgrims have significant direct and indirect effects on the watershed leading to the city and surrounding over the past four decades. there is no collection system and sanitation disposal network in towns and villages within the torghabeh river.  meth...

River ecosystems are influenced by processes operating and interacting on a variety of spatial scales. Quantifying the interplay of large and small-scale processes is central to both a basic ecological understanding of river ecosystems as well as the development of effective watershed management strategies. A key management goal for many western rivers restricted by large dams is to restore eco...

American Dippers concentrate on low-elevation streams during fall and winter in many parts of their range; however the breeding origin relative to the wintering location is poorly understood. Our objectives were to identify seasonal changes in the density and distribution of American Dippers, to classify the migratory behavior of the local population, and to determine the origin of winter migra...

Agricultural runoff can be a source of P, a limiting factor for freshwater eutrophication. To develop a simple method to estimate P export from the cropland, we studied 1.2-p.m filtered dissolved phosphorus (DP) output from four tiles draining areas ranging from 8 to 25 ha, and from a river draining a 48 173 ha watershed in eastcentral Illinois during 1993 to 1996. The land was under maize (Zea...

A foundational element in determining Total Maximum Daily Loads (TMDLs) is the determination of the relative impacts of point and nonpoint source impacts on the dissolved oxygen concentration (DO) of an impaired stream. It is not uncommon that the ultimate oxygen demand during a rain event can be greater than the effects of the fully permitted point source loading to the stream. Traditionally, ...

This research was conducted to develop relationships among evapotranspiration (ET), percolation (PERC), groundwater discharge to the stream (GWQ), and water table fluctuations through a modeling approach. The Soil and Water Assessment Tool (SWAT) hydrologic and crop models were applied in the Big Sunflower River watershed (BSRW; 7660 km(2) ) within the Yazoo River Basin of the Lower Mississippi...

The authors developed a simple screening-level model of exposure of aquatic species to pyrethroid insecticides for the lower American River watershed (California, USA). The model incorporated both empirically derived washoff functions based on existing, small-scale precipitation simulations and empirical data on pyrethroid insecticide use and watershed properties for Sacramento County, Californ...

Document Title: Study 200: Protocol for monitoring acute and chronic toxicity in the San Joaquin River watershed, winter 2000-200 1

Human activities pose a significant threat to the water quality of rivers when pollution exceeds the threshold limit. Urban activities in particular are highlighted as one of the major causes of contamination in surface water bodies in Asian countries. Evaluation of sustainable human population capacities in river watersheds is necessary to maintain better freshwater ecosystems in a country whi...