| The key to keep healthy river eco environment system is to meet its eco environment water requirements. The Range of Variability Approach (RVA) is widely used to study the river hydrological change. This paper put forward the calculation method for the eco-environment water requirements
based on the RVA threshold. This method has been applied to three sections as Linjiacun, Xianyang, Huaxian in the middle and downstream of Weihe River, obtained the eco environment water requirements of these three sections was 529.5 million m3， 1.1274 billion m3 and 2.3908 billion m3， respectively. Compared with the past research results, this method has certai
n applicability. By analyzing the satisfaction of ecological water requirements at different period in these three sections, obtained the minimum value of the satisfaction was occurred and focus on the flood season as May, June, August and September. As a result, when carries out the water resources allocation, the eco environment water requirements in flood season should be more paid attention. |