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Nonpoint source pollution, watershed management, conservation practices, hydrologic/water quality models


Nonpoint source (NPS) pollution models have shown promise in evaluating effects of conservation practices (CP) before these practices can be implemented in the field. An increasing trend has been noted in use of NPS pollution models for assessing effectiveness of CPs. The increase in use of NPS pollution models necessitates their continuous development and improvement. Model improvements will help assess water quality impacts of CPs more accurately. Apart from assessing effectiveness of different CPs, models can also help in identifying suitable location for targeting CPs in a watershed. However, there are challenges associated with modeling CPs such as selecting the best type of CP, best location of CP placement, reliable calibration of the model, validation of modeling results with observed field data, and proper documentation of the modeling process. This paper discusses hydrologic/water quality models used to simulate various CPs in a watershed along with the associated challenges and potential future directions for NPS modeling.