Effects of watershed changes: a continuing challenge;Effects of watershed changes on water quality;Potential of physical models for achievingbetter understanding and evaluation of watershed changes;A discussion of potential of physical models for achieving better understanding an evaluation of watershed changes; Analysis of watershed changes; Informational needs on changes in rural watershed and their relationship to planning activities; Land treatment in agricultural watershed hydrology research; Effects of conservation treatments on water yield; Application of continuous accounting techniques to evaluate the effects of small structures on mukewater Creek, Texas; A discussion of application of continuous accounting techniques to evaluate the effects of small structures on mukewater creek, Texas; Effects of small structures on peak flow; Effects of small structures on water yield in Texas; Effects of small structures on water yield in Texas; Field experiment on washita river; Pollution effects in rural watersheds; The nature of changes in urban watersheds and their importance in the decades ahead; The U.S. geological survey urban water program; Urban effects on water yield; Modeling the runoff characteristics of a urban watershed by means of an analog computer; Effects of urbanization on peak flows; Urban effects on the unit hydrograph; Experience with the evaluation of urban effect for drainage design; Urban effect of quality of streamflow.

This work advises owners and managers how woodlands and forests influence the freshwater ecosystem, and gives guidance on how operations should be carried out in order to protect and enhance the water environment. The guidelines apply equally to forest enterprises and the private sector.

Globally, more than 700 million people live in watersheds with a degraded ability to provide hydrologic ecosystem (hydro-eco) services, such as improved water yield and moderation of peak and dry-season river flows. Restoring pre-development land cover to provide hydro-eco services has become a major driver of conservation. This dissertation investigates the hydrologic response to land-cover change in high-resolution hydrologic models of 32 watersheds spanning six continents and diverse climate zones. The watershed site models are used to explore streamflow changes for scenarios of land-cover restoration to a pre-development state, as well as land-cover development to agricultural or urban conditions. The site models are used to simulate land-cover change of 10% of watershed area, which is larger than the area typically selected for hydro-eco service investment. On average the magnitude of annual average water yield, low flow, and high flow are reduced 1-3% under restoration. The magnitude is similar but the direction reversed for development to agricultural or urban conditions. Focusing on restoration, results show that groups of watersheds have similar streamflow response characteristics to land cover-change despite the limited response magnitude. The groups are identified using a graph-connectedness approach based on the sign correlation of changes in 26 streamflow index values. Watersheds fall into three clusters characterized by their hydrologic responses to land-cover change: 1) low-flow intensifying, 2) high-flow intensifying, and 3) high-flow enhancing. Non-parametric hypothesis testing is used to identify which particular streamflow indices, watershed features, and pre-restoration flow features are characteristic of watersheds in the respective clusters. Under restoration, sites in the low-flow intensifying cluster exhibit an increase in low flow and a decrease in high flow. Sites in the high-flow intensifying cluster show high flow increases (relative to each site's median flow) and low flow decreases. The high-flow enhancing cluster behaves like the high-flow intensifying cluster, but has smaller reductions in low flows. Soil characteristics in the sites are distinct across clusters. Watersheds with smaller soil depths and available soil water content fall into the low-flow intensifying cluster, and these soil characteristics are statistically different from those of sites in the high-flow enhancing and intensifying clusters. After restoration, the low-flow intensifying watersheds typically exhibit greater infiltration and shift water to the low-flow regime. This flowvi regulating behavior is a desired effect of watershed restoration. In contrast, high-flow intensifying watersheds exhibit increased transpiration that reduces low flow. Such behavior is detrimental to regions with limited water availability. This study uses local hydrologic site models in a broad range of conditions to better understand how landcover changes affect hydrologic response and under what conditions such changes might enhance hydro-eco services. Results contribute useful guidance about the generally limited effects of land-cover change on water yield. This work also provides useful understanding about key watershed characteristics that affect streamflow responses to restoration.

Filling a long-standing need for a desk reference that synthesizes current research, Land Use Effects on Streamflow and Water Quality in the Northeastern United States reviews and discusses the impact of forest management, agriculture, and urbanization. The book provides a gateway to the diverse scientific literature that is urgently needed