Abstract:
It is necessary to develop a water balance for urban areas to establish the effect of urbanization. It is used to calculate the daily, monthly, and annual water balance components for an urban catchment in scope of designing and operating an integral urban water management system. The calculation considers both natural and man-induced water sources. In achieving the water balance in the urban area we excluded groundwater. Through this paper we want to show the importance of evapotranspiration to achieve water balance in urban areas and different methods for determining evapotranspiration using physically based equation or by measuring it.