Quantifying Analysis of Hydrological Conditions Dynamic Alteration and its Multiple Influencing Factors

Abstract

Hydrological condition is of great significance to river ecosystems. Alteration in hydrological conditions can directly or indirectly affect ecosystems, causing changes in river ecological health, species habitats, and water-sand relationships. In this paper, the Index of Hydrologic Alteration-Range of Variability Approach method (IHA-RVA) method was used to evaluate the alteration of hydrological condition in Yuanshui river from 1959 to 2010 under the combined action of climate change and human activities. We have reached the conclusion that the current hydrological condition alteration in the Yuanshui River Basin is moderately changing; Regardless of the water diversion, the contribution rates of natural runoff changes and cascade reservoir operations to hydrological change is 58% and 42% respectively, which were quantified by the multi-series contribution rate segmentation method. It can be seen that the natural runoff change was the leading cause of the change of the overall hydrological situation, and the operation of the cascade reservoir was an important cause of the hydrological situation change.