Agricultural non-point source (NPS) pollution poses a severe threat to water quality and aquatic ecosystems. In response, tremendous efforts have been directed toward reducing these pollution inputs by implementing agricultural conservation practices. Although conservation practices reduce pollution inputs from individual fields, scaling pollution control benefits up to the watershed level (i.e...

Chloride is a relatively unreactive plant nutrient that has long been used as a biogeochemical tracer but also can be a pollutant causing aquatic biology impacts when concentrations are high, typically from rock salt applications used for deicing roads. Chloride inputs to watersheds are most often from atmospheric deposition, road salt, or agricultural fertilizer, although studies on agricultur...

The Terrain Resources Inventory Mapping (TRIM) data standard in BC, Canada, includes speci cations for river data and elevation data that are typically met by interpretation of stereo orthophotos. It does not specify that breaklines for watersheds be interpreted from the photos, thus we must extract them from the data. We seek a system of watersheds that, while not exact due to errors in the da...

When improperly managed, land application of animal manures can harm the environment; however, limited watershed-scale runoff water quality data are available to research and address this issue. The water quality impacts of conversion to poultry litter fertilization on cultivated and pasture watersheds in the Texas Blackland Prairie were evaluated in this three-year study. Edge-of-field N and P...

Wildfire is an important and prevalent agent of disturbance in vegetated landscapes across much of the Earth’s surface, including forested watersheds in the arid western USA. Between 1992 and 2003, >40% of the watersheds in the upper reaches of the Boise River watershed in central Idaho burned. The purpose of our study was to investigate the legacy effects of wildfire on stream ecosystems by an...

Fractal scaling behavior of long-term records of daily runoff time series in 31 sub-watersheds covering a wide range of size were examined using the shifted box-counting method and Hurst rescaled range (R/S) analysis. These subwatersheds were associated with four agricultural watersheds of different climate and topography. The results showed that the records of daily runoff rate exhibited scale...

Surface water samples of baseflow were collected from 20 headwater sub-watersheds which were classified into three types of watersheds (natural, urban and agricultural) in the flood, dry and transition seasons during three consecutive years (2010-2012) within a coastal watershed of Southeast China. Integrating spatial statistics with multivariate statistical techniques, river water quality vari...

There has been a steady shift towards modeling and model-based approaches as primary methods of assessing watershed response to hydrologic inputs and land management, and of quantifying watershed-wide best management practice (BMP) effectiveness. Watershed models often require some degree of calibration and validation to achieve adequate watershed and therefore BMP representation. This is, howe...

This paper examines the effects of urbanization on the flood hazard in semi-arid/arid southern California using traditional hydrograph, frequency-magnitude and statistical analysis augmented with GIS-based variable parameterizations and visualizations. It was found that the peak flood discharges were significantly increased in urban watersheds in conjunction with increasing mean baseflow in the...

This study focuses on the differential hydrologic response of individual watersheds to climate warming within the Sierra Nevada mountain region of California. We describe climate warming models for 15 west-slope Sierra Nevada watersheds in California under unimpaired conditions using WEAP21, a weekly one-dimensional rainfall-runoff model. Incremental climate warming alternatives increase air te...