[1] Watershed-scale water quality models involve substantial uncertainty in model output because of sparse water quality observations and other sources of uncertainty. Assessing the uncertainty is very important for those who use the models to support management decision making. Systematic uncertainty analysis for these models has rarely been done and remains a major challenge. This study aimed...

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 ...

Several best management practices (BMPs) have been implemented through Water Quality Management Plans (WQMPs) in the West Fork Watershed of Trinity River Basin in Texas, USA, where nonpoint source pollution is a serious concern. Major sources of pollution are sediment erosion and nutrients. The objective of this study was to evaluate the long-term impact of implementation of WQMPs on nonpoint s...

First posted October 27, 2022 For additional information, contact: Director, New England Water Science CenterU.S. Geological Survey10 Bearfoot RoadNorthborough, MA 01532 The U.S. Survey has been working in collaboration with the Massachusetts Department of Environmental Protection on a project to collect water-quality data from Merrimack River watershed since April 2020. Twelve locations are be...

Due to the global climate change and substantial increase in impervious area, ‘never flooding’ becomes an unrealistic goal. From perspective of integrated flood management, government a...

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...

This project outlines procedures and resources used on the construction of polycyclic aromatic hydrocarbon (PAH) susceptibility model. The PAH susceptibility is due to PAH loading from impervious surface features in the watershed. The susceptibility model determines areas in the watershed which contribute to PAH loading. These hotspots represent areas that should be closely monitored, as they h...

Passage of the original Social Security Act in 1935, Public Law (P.L.) 74-271, represented one of the watershed achievements of social welfare reform in American history. For the first time, workers were guaranteed a basic floor of protection against the hardships of poverty. In the ensuing decades, more than 100 million beneficiaries have realized the value of this protection through the recei...