Analysis of Water Resource Demands: Based on the Hydrological Unit

It is important to take into account land use when considering water resource demands. The Hydrological unit is defined as the assimilation of land use and soil properties into a lumped element, spatially separate area which exhibits a typical hydrological reaction. Using physically based equations, water balance can be calculated and compared for different hydrological units and thus water resources can be assessed. The Huanghua City in Hebei province is taken as an example to analyze the hydrological elements of water resources supply and demand for different land use types. Huanghua City is located in the alluvial plains, which is flat, and geologically uniform. The altitude is generally in 2.5-5m above sea level. The geomorphology consists of an ancient river course, depressions, shallow depressions, ancient shell dikes and lagoons, typical characteristics of a coastal plain.