The low-flow regime of a river may be described in terms of various characteristics (indices). These characteristics may have multiple use in different areas of water-related research and practice and uncertainty often exists as to which low-flow characteristic is the most suitable for a specific purpose. The paper illustrates that many low-flow characteristics exhibit a strong intercorrelation...

We study the geometric shortest path and the minimum spanning tree problem with neighborhoods in the L1 metric. In this setting, we are given a graph G = (R, E), where R = {R1, . . . , Rn} is a set of polygonal regions in the plane. Placing a point pi inside each region Ri turns G into an edge-weighted graph Gp, p = {p1, . . . , pn}, where the cost of an edge is the distance between the points....

ii NOTICE The U.S. Environmental Protection Agency through its Office of Research and Development partially funded and collaborated in the research described here under Cooperative Agreement No. CR-822204 to the University of California, Davis. It has been subjected to the Agency's peer and administrative review and has been approved for publication as an EPA document. Mention of trade names or...