Spatio-temporal analysis of satisfactory degree of ecological water demand in Huaihe River Basin

In order to reflect the statuson instream flow to meet the demand of ecological protection and restoration, this study adopts dynamic calculation method of ecological water demand to calculate the satisfactory degree of ecological water demand of the main rivers in the Huaihe River Basin. Based on the Cluster analysis, Mann-Kendall test and the function of spatial analysis of GIS, this papermainly addresses identification of the sensitivity areas and periods of the satisfactory degree of ecological water demand, and its spatial distribution characteristics. The results sho wthat; (1) Overall, satisfactory degree of ecological water demand in this basin is higher in the west thanthat in the east, higher in the north and lower in the south; (2) Satisfactory degrees of ecological water demand in the Yinghe, the Wohe and the Tuohe rivers are lower, and present a significant downward trend; (3) The satisfactory degree of ecological water demand at the third period (Apr-Jun) is the lowest, and has the largest spatial difference. So, it can be recognized as the sensitive period of the ecological water demand; and (4) The sensitivity areas of ecological water demand are some sub-basins in the Huaihe River Basin, such as the Wohe, the Chihe and the Tuohe rivers. Ecological water demand in these rivers cannot be guaranteed at more than one-third of the time in a year. ©, 2015, China Water Power Press. All right reserved.