This thesis provides a rigorous statistical analysis of whether agricultural best management practices (BMPs) have reduced total dissolved phosphorus (TDP) loads from dairy farms in the Cannonsville Reservoir basin in New York State, a drinking water supply for New York City. This paper introduces the use of a simulation model as a control site in a paired watershed analysis as a technique that...

Land use and land cover can have a significant impact on water chemistry, but the spatial scales at which landscape attributes exert a detectable influence on aquatic systems are not well known. This study quantifies the extent of the landscape influence using the proportion of wetlands in the watershed measured at different distances to predict dissolved organic carbon (DOC) concentrations in ...

An efficient model to store and retrieve surface watershed boundaries using graph theoretic approaches is proposed. Our approach utilizes three algorithms and accepts as input standard digital elevation models derived stream catchment boundaries. The first is called Modified Nested Set (MNS), which is a generalized depth first graph traversal algorithm that searches across stream reaches (verti...

With regard to the importance of instantaneous peak discharge estimation for watershed management study, and due to the lack of and unqualified climatic and hydrologic data for estimation and measurement in countries such as Iran, researchers were obliged to establish a link between constant parameters (geomorphologic) and variables (hydrologic) to present models with minimum dependence on clim...

Non-point sources of pollutants originate at the field scale but water quality problems usually occur at the watershed or basin scale. This paper describes a series of models developed for poorly drained watersheds. The models use DRAINMOD to predict hydrology at the field scale and a range of methods to predict channel hydraulics and nitrogen transport. In-stream changes of N load are estimate...

The Cannonsvifle Reservoir watershed is a major component of the unfiltered New York City water suppiy system. The voluntary, incentive-based Watershed Agricultural Program is a collaborative effort among producers, federal, state, and local organizations to address the problem of phosphorus loading effects on water quality through implementation of whole-farm plans. The effectiveness of select...

Water becomes, every day, more scarce. Reliable information about volume and quality in each watershed is important to management and proper planning of their use. Data-intensive science is being increasingly needed in this context. Associated analysis processes require handling the drainage network that represents a watershed. This paper presents an ongoing work that explores geographic waters...

The results of distributed watershed models could be sensitive to spatial and temporal scales at which inputs and model parameters are aggregated. This paper reports findings of a detailed sensitivity analysis conducted on the U.S. Department of Agriculture’s distributed watershed simulation model, known as the Soil and Water Assessment Tool (SWAT). The Big Creek Watershed, located in southern ...

Because hydrologic responses of an agricultural watershed are influenced by many natural and man-made factors including pond/reservoir, management practices, and/or irrigation/drainage, strategies of hydrological modeling for the watershed must be case-dependent and thus carefully designed to effectively reflect their roles as critical hydrologic components in simulation processes. In this stud...