Land use and land cover across 28 sub-basins within the Cosumnes Watershed, CA (1989 km) were correlated to nitrate-N and total suspended solids (TSS) loading between water years 1999 and 2001. The impact of human development on stream water quality was evident as both agricultural area and population density predicted TSS loading in a linear mixed effects model. In contrast to the TSS model, t...

A new regulatory approach is needed to characterize peak pesticide concentrations in surface waters over a range of watershed scales. Methods now in common use rely upon idealized edge-of-field scenarios that ignore scaling effects. Although some watershed-scale regulatory models are available, their complexity generally prevents them from being used duringthe pesticide registration decision pr...

Integrated Environmental Modeling (IEM) organizes multidisciplinary knowledge that explains and predicts environmental-system response to stressors. A Quantitative Microbial Risk Assessment (QMRA) is an approach integrating a range of disparate data (fate/transport, exposure, and human health effects relationships) to characterize potential health impacts/risks from exposure to pathogenic micro...

Most stormwater numerical models assume that the entire watershed area is under the design storm and shall be considered as the tributary area to the design point. Care must be taken when simulating storm runoff generation from a large watershed because the rain storm may only cover a portion of the watershed. Since the area-averaged rainfall depth decays with respect to the storm-cover area, t...

Much of the Watonwan River tributary system to the upper Mississippi River basin (UMR), and the fluvial systems to which it drains, are listed as impaired under the United States Environmental Protection Agency Clean Water Act303(d) and/or by the Minnesota Pollution Control Agency. In addition, eutrophic conditions and excessive sedimentation rates exist in Lake Pepin, a riverine lake to which ...

Turbidity regimes vary dramatically among small streams in north coastal California. In an analysis of turbidity data from 27 small streams in the region, turbidity at the 10-percent exceedence level ranged from 3 to 116 formazin nephelometric units (FNU) for the 2005 wet season, translating to 1.7 to 65 days above an oft-cited biological threshold of 25 FNU. Watersheds draining to the streams ...

Two different methods utilizing geographical information systems (GIS) and digital elevation models (DEMs) are described and evaluated for applying the Water Erosion Prediction Project (WEPP) model to assess water erosion and runoff in small watersheds. The first approach, called the Hillslope method, presents an automated method for the application of WEPP through the extraction of hillslopes ...

James C.Y. Guo, PhD, P.E. Professor, Department of Civil Engineering, University of Colorado at Denver, Denver, Colorado 80204. E-mail: [email protected] ___________________________________________________________________________________________ Abstract: A semi-virtual watershed model is presented in this study. This model places the design rainfall distribution on the input layer and t...

An approach of abnormality detection from color fundus images for automated mass screening system is proposed in this paper, which uses the object-based color difference image. Four color models, i.e. RGB, Luv, Lab and HVC are evaluated based on the hand labeled feature maps, and Luv and Lab are selected for computing color difference because of their good performance of object classification. ...