We study the flow of water on fat terrains, that is, triangulated terrains where the minimum angle of any triangle is bounded from below by a positive constant. We show that the worstcase complexity of any path of steepest descent on a fat terrain of n triangles is Θ(n), and that the worst-case complexity of the river network on such terrains is Θ(n). This improves the corresponding bounds for ...

In 1998 and as part of a science cooperation and technology transfer effort, the Hydrologic Research Center (HRC) and collaborators designed and implemented at the Panama Canal Authority (PCA) a prototype forecasting system for the real time rainfall forecasting over a number of small sub-catchments of the 3,200-sqkm mountainous Panama Canal Watershed in Panama (Figure 1). The system (called PA...

Despite some highly visible projects that have resulted in environmental benefits, recent efforts to quantify the number and distribution of river restoration projects revealed a paucity of written records documenting restoration outcomes. Improving restoration designs and setting watershed priorities rely on collecting and making accessible this critical information. Information within the unp...

Impacts of land cover changes on watershed hydrology have been a long-term academic concern with acute dispute. But little attention has been paid to such effects on mesoscale river basins, where the society has a closer link to river hydrology. The present study focuses on a mesoscale river basin, the Suomo Basin that is located on the upper reaches of the Yangtze River. Land covers in the bas...

Recent findings in the Umpqua River Basin in southwestern Oregon illustrate a tension in the rise of both community-based and watershed-based approaches to aquatic resource management. While community-based institutions such as watershed councils offer relief from the government control landowners dislike, community-based approaches impinge on landowners' strong belief in independence and priva...

Transport of pesticides by surface runoff during rainfall events is a major process contributing to pesticide contamination in rivers. This study presents an empirical regression model that relates pesticide loading over time in the Sacramento River with the precipitation and pesticide use in the Sacramento River watershed. The model closely simulated loading dynamics of diazinon, simazine, and...

The objective of this study was to evaluate the impact of rapidly changing land use on erosion and sedimentation in a mixed land use watershed in the Ozark Highlands of the USA. The research combines a geographic information system-based soil erosion modeling approach with land use change detection to quantify the influence of changing land use on erosion risk. Five land use/land cover maps wer...

Excessive nitrogen (N) loading to N-sensitive waters such as the Neuse River Estuary (North Carolina) has been shown to promote changes in microbial and algal community composition and function (harmful algal blooms), hypoxia/anoxia, and fish kills. Previous studies have estimated that wet atmospheric deposition of nitrogen (WAD-N), as deposition of dissolved inorganic nitrogen (DIN: NO3, NH3/N...

Process-based restoration aims to reestablish normative rates and magnitudes of physical, chemical, and biological processes that sustain river and floodplain ecosystems. Ecosystem conditions at any site are governed by hierarchical regional, watershed, and reach-scale processes controlling hydrologic and sediment regimes; floodplain and aquatic habitat dynamics; and riparian and aquatic biota....