Groundwater Evapotranspiration — Underestimated Role of Tree Transpiration and Bare Soil Evaporation in Groundwater Balances of Dry Lands

摘要

This paper analyzes and emphasizes the importance of groundwater evapotranspiration (ETg) in groundwater balances. The ETg diminishes the net groundwater recharge that constrains groundwater flow and replenishment of groundwater resources. The ETg consists of two different components, groundwater transpiration (Tg) and groundwater evaporation (Eg), both not yet well identified in hydrogeology. The ETg values are the largest in dry locations with shallow groundwater table. The significance of the ETg however is the largest when its relative contribution to groundwater balance is high i.e. when its rate is comparable with groundwater recharge.