Abstract: “Hydrological resource shed” is defined as a geographic area that contributes material (e.g. water, nutrients, and sediments) over one time interval, passing through a location of interest over another time interval. While similar to the concept of watershed, this relatively new concept has some unique features. First, the boundary of a watershed is delineated by topography and relatively more stable.  The boundary of a hydrologic resource shed, however, is delineated by the contributing sources of water and materials to a river or lake during hydrologic events, and changes over both space and time. Second, the concept of watershed emphasizes temporal distribution of water and materials within a given space, and the hydrologic resource shed focuses on both temporal and spatial distribution of water and materials within a changing space. Third, the concept of hydrologic resource shed incorporates the space-time variability in studying watershed patterns and processes. Taking advantage of current tracing, remote sensing, mapping, and modeling technologies, hydrologic  resource shed  provides a new way of discovering, understanding, and simulating the transport and distribution of water and materials across multiple space and time scales. An example is presented for computing the hydrologic resource shed distributions using a hydrologic model, Distributed Large Basin Runoff Model (DLBRM)  in the Maumee River watershed in western Lake Erie Basin of the U.S.

Key words: hydrologic resource shed, runoff, hydrologic model, DLBRM, Lake Erie