These proceedings record the results of climate change in many areas which are hyper-arid deserts today but which, almost cyclically, at intervals of thousands or even hundreds of thousands of years, have had a much more humid climate.

Since human beings first appeared on the earth, we have changed land cover and land use for our own purposes, such as conveniences and high productivity. As a result of the land cover and land use changes, many serious environmental problems occur on the earth. Studying meteorological and hydrological effects of vegetation and land cover/use changes helps us to understand the environmental changes and problems happening near the earth surface, because the vegetation distributes the solar energy and water on the earth surface into atmosphere and geosphere. Subsurface hydrological responses to land cover and land use changes have drawn only regional environmental concerns, although global change caused by biosphere change has been studied in various scientific fields. The changes in land cover and land use alter water, solute and heat cycles in basins and elements of those balances, including evapotranspiration, groundwater recharge rate, discharge rates into rivers or ocean and soil moisture content, which are directly or indirectly related to the global environmental issues. Therefore, the changes in biosphere may substantially alter the subsurface hydrological system. For instance, increased groundwater recharge rates following clearing forest into grasses might be one consequence resulting in rising water tables and salinization.

Papers in this title were selected from presentations from an April 2005 workshop sponsored by the U.S. Geological Survey Earth Surface Dynamics Program, the U.S. Geological Survey National Cooperative Geologic Mapping Program, and the Smithsonian Institution. Papers are divided into two broad topics of the configuration, areal extent, and temporal development of the chain of interconnected lakes that emptied into Death Valley during periods of the Pleistocene, and the late Cenozoic history of drainage integration in the lower Colorado River region. Papers are occasionally illustrated in both color and black-and-white; the publication contains no index.