Book excerpt: 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.