GIS based synthetic watershed sediment routing model

For most watersheds, extensive water quality data are not available. Land use, topographic, edaphic and meteorological information is generally available; but without extensive water quality data, it is difficult to accurately calibrate and verify a continuous nonpoint source model such as HSPF. However, if the spatial and physical attributes of a watershed can be assembled into a geographic information system (GIS) data base, this information could potentially be used to generate synthetic water quality data by a simplistic approach. This paper focuses on the development of a GIS (ARC/INFO) based synthetic watershed sediment routing model. An important problem, particularly in a large watershed, is the transport of sediment produced in the subwatersheds to the outlet of the whole watershed. This problem is approached mathematically by a sediment routing equation that is based on the streamflow component of the total model. The synthetic model is applied to the 56.3 square mile North Reelfoot Creek watershed, located at the Northwest corner of the state of Tennessee. The results of this synthetic model are then compared with those from an integrated GIS-HSPF model and with the observed data