[1] Distributed hydrological models have the potential to provide improved streamflow forecasts along the entire channel network, while also simulating the spatial dynamics of evapotranspiration, soil moisture content, water quality, soil erosion, and land use change impacts. However, they are perceived as being difficult to parameterize and evaluate, thus translating into significant predictiv...

Hydrologic response varies within a watershed as a function of topography, soil, and land cover. Spatial and temporal data from experimental watersheds may provide information on where, when, how, and why the response varies. This study examined the hydrologic response of an agricultural watershed, FD-36, in the Appalachian Valley and Ridge physiographic region. FD-36 is characterized by shallo...

In this paper we propose an algorithm and associated data model for creating a watershed boundary using a 2D Flow Direction Grid. Flow Direction Grids (FDGs) are common abstractions for hydrodynamic models and are utilized for delineating physical systems (e.g. watersheds, fluvial, and non-fluvial flow paths). The proposed algorithm and associated data model provides geometric speed increases i...

Common methods for spatial distribution, such as hydrologic response units, are subjective, time-consuming, and fail to capture the full range of basin attributes. Recent advances in statistical-learning techniques allow new approaches this problem. We propose use Gaussian Mixture Models (GMMs) distribution models. GMMs objectively select set modeling locations that best represent watershed fea...

Selecting the right model to simulate a specific watershed has always been a challenge, and field testing of watersheds could help researchers to use the proper model for their purposes. The performance of three popular Geographic Information System (GIS)-based watershed simulation models (European Hydrological System Model (MIKE SHE), Agricultural Policy/Environmental Extender (APEX) and Soil ...

Complicated research and management questions regarding watershed systems often require the use of more than one simulation model. Therefore, it is necessary to develop a means to integrate multiple simulation models to predict holistic system response. In this paper we explore the use of a componentbased approach for the runtime integration of models, implemented as “plugand-play” software com...

Two lumped parameter watershed scale hydrology and water quality models (WATGIS and QUALGIS) which describe the nitrogen loadings at the’outlet of coastal plain watersheds were examined with respect to their accuracy and uncertainty of model results. Latin Hypercube Sampling (LHS) was applied to determine the impact of uncertainty in estimating field exports and decay coefficients on the uncert...

Historical and recent remote sensing data can be used to address temporal and spatial relationships between upland land cover and downstream vegetation response at the watershed scale. This is demonstrated for sub-watersheds draining into Elkhorn Slough, California, where salt marsh habitat has diminished because of the formation of sediment fans that support woody riparian vegetation. Multiple...

This study was conducted under the USDA-Conservation Effects Assessment Project (CEAP) in the Cheney Lake watershed in south-central Kansas. The Cheney Lake watershed has been identified as ‘impaired waters’ under Section 303(d) of the Federal Clean Water Act for sediments and total phosphorus. The USDA-CEAP seeks to quantify environmental benefits of conservation programmes on water quality by...