陆地系统生态需水量计算方法初探

人类活动的影响等使得生态环境日益恶化严重，也引起了一系列的水问题。生态需水量是反映生态系统安全的一个阈值，因此确定不同生态类型的生态需水量，是生态环境建设的重要内容。为了对陆地生态需水量进行研究，根据Hargreaves算法计算植被蒸腾，进而计算总的陆地蒸散量，对陆地生态需水进行了计算；利用水循环的观点对陆地生态需水进行了研究。通过一个实例，利用Hargreaves算法以及所提出的方法对某一流域的陆地系统进行生态需水的研究，并对二者进行了分析比较。结果表明两种计算方法差别不大，在20％左右。

Preliminary Discussion on the Ecological Water Demand of Terrene System

With the influences of the human activities, the ecological environment is deteriorating, and a series of water problems are brought out. The ecological water demand is a threshold reflecting the safety of the ecosystem. So it is important for the environmental protection to determine the ecological water demands of different ecosystems. In order to study the ecological water demand of the terrene system, the Hargreaves Algorithm is used to calculate the vegetation evaporation and transpiration, the total evapotranspiration, and the ecological water demand of the terrene system. And the method of hydrological cycle is used to study the ecological water demand of the terrene system. Case study on the ecological water demand of a watershed of the terrene system is conducted to compare between the results of Hargreaves Algorithm and those of the method proposed. The comparison shows that the difference between the two methods is about 20%, so it is not significant.