关键词: 水文改变度, 生物多样性, 水文情势, RVA法, Mann-kendall检验法, 尼尔基水库

Abstract: The Mann-Kendall test was used to do the mutability test of the annual average discharge of Tongmeng Station II on Nenjiang River. The RVA method was used to analyze the influence of the operation of Nierji Hydro Project on the downstream from the aspects of river hydrological status and ecological diversity. The study results showed that the extreme flow, the frequency and duration of low flow pulse, the rise and fall rates of runoff and number of flow reversal after the operation of Nierji Reservoir changed significantly. The overall hydrological change degree of the downstream was 51%, a moderate change. The mean value of biodiversity index decreased from 24 to 18 after the operation of reservoir. The biodiversity and biomass in the lower reaches of Nierji River decreased, and the ecosystem presented a degradation trend.

Key words: degree of hydrological change, biodiversity, hydrological situation, RVA method, Mann-Kendall test, Nierji Reservoir;