AFINCH provides a basis for integrating monthly flow data from streamgages, water-use data, monthly climatic data, land-cover and catchment attributes described in user-defined shapefiles to estimate natural monthly water yields from catchments. AFINCH provides an interactive process for the user to develop sets of multiple-regression equations for estimating monthly water yields. Images of monthly water yields for active streamgages are generated in AFINCH and provide a basis for detecting anomalies in water yields, which may be associated with undocumented flow diversions or augmentations. Water yields are multiplied by the drainage areas of the corresponding catchments to estimate monthly flows. Flows from catchments are accumulated downstream through the streamflow network described by the stream segments. For stream segments where streamgages are active, computed flows are constrained to match measured flows. Flow is conserved through the NHDPlus network. Generated time series of monthly flows can be tested for trends and used to develop monthly flow duration curves. For more information, see the report.
