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RIST - Rainfall Intensity Summarization Tool

RIST - Rainfall Intensity Summarization Tool - 3.98

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AnnAGNPS - Annualized AGricultural NonPoint Source model

The Annualized Agricultural Non-Point Source Pollution Model (AnnAGNPS) is a continuous simulation watershed-scale program. The model is an expansion of the capabilities developed in the single event model AGNPS and is the pollutant loading model in the suite of models for the next generation of the suite of AGNPS modeling components. To use AnnAGNPS, the watershed is subdivided into homogenous land areas with respect to soil type, land use, land management, and climate. Areas can be of any shape including hydrologically-based or square grid (as was used in the single-event AGNPS). AnnAGNPS simulates quantities of surface water, sediment, nutrients, and pesticides leaving the land areas (cells) and their subsequent travel through the watershed. Some of the sediment, nutrients, and pesticides will reach the watershed outlet while the remainder will be deposited in the stream system. Calculations are done on a daily time step. Runoff quantities are based on runoff curve number while sheet & rill sediment is determined using RUSLE. Special components are included to handle concentrated sources of nutrients (feedlots and point sources), ephemeral gully sources, concentrated sediment sources (classical gullies), added water (irrigation), and the impacts of riparian buffers and wetlands. Output is expressed on an event basis for selected stream reaches and as source tracking (contribution to outlet or any other point in the watershed) from land or reach components over the simulation period.