State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Northwest A&F University, Yangling, Shaanxi 712100, China; Institute of Soil and Water Conservation, Chinese Academy of Sciences & Ministry of Water Resources, Yangling, Shaanxi 712100, China.
State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Northwest A&F University, Yangling, Shaanxi 712100, China; Institute of Soil and Water Conservation, Chinese Academy of Sciences & Ministry of Water Resources, Yangling, Shaanxi 712100, China.
Sci Total Environ. 2019 Nov 25;693:133556. doi: 10.1016/j.scitotenv.2019.07.362. Epub 2019 Jul 23.
Understanding hydrological alteration of rivers and the potential driving factors are crucial for water resources management in the watershed. This study analyzed the daily runoff time series at six gauging stations during 1960-2016 in Wuding River basin, northwestern China. The Mann-Kendall test and Lee-Heghinian method were employed to detect the temporal trends and abrupt changes in annual streamflow. The flow duration curve (FDC) and the index of hydrologic alteration (IHA)/Range of Variability Approach (RVA) were applied to assess the daily streamflow and degree of hydrologic alteration (DHA). In addition, we analyzed the changes of index of hydrological connectivity (IC) and reservoirs/dams (RI) in 1990, 1995, 2000 and 2015 in the basin. The relationship between IC, RI and DHA were assessed to investigate the potential influences of land use changes and constructions of reservoirs/dams on hydrological alteration. The results indicated that annual streamflow at five stations showed significant downward trends (p < 0.01) from 1960 to 2016, and an abrupt changing point appeared in the beginning of 1970s in Wuding River basin. Exception is Qingyangcha station without significant changes, and Hanjiamao station with changing point in 1967. FDC analysis indicated that both high and low flow indices reduced greatly. The integral DHA were higher than 70% at all the stations in the Wuding River basin, suggesting great variation in the magnitude, duration, frequency, timing and rate of change of daily streamflow. Both IC value and RI had close relationship with DHA, implying that DHA was highly affected by land use changes and dams/reservoirs constructions, and was more sensitive to the land use change (p < 0.01). This study provides good insight to understand the effects of soil and water conservation measures on hydrological regime.
了解河流的水文变化及其潜在驱动因素对于流域水资源管理至关重要。本研究分析了 1960 年至 2016 年期间中国西北部武定河流域六个测站的日径流时间序列。采用 Mann-Kendall 检验和 Lee-Heghinian 方法检测年径流量的时间趋势和突变。应用流量持续曲线（FDC）和水文变化指标（IHA）/变异性范围方法（RVA）评估日流量和水文变化程度（DHA）。此外，我们分析了流域内 1990 年、1995 年、2000 年和 2015 年的水文连通指数（IC）和水库/大坝（RI）的变化。评估了 IC 和 RI 与 DHA 之间的关系，以调查土地利用变化和水库/大坝建设对水文变化的潜在影响。结果表明，1960 年至 2016 年期间，五个站的年径流量呈显著下降趋势（p<0.01），武定河流域在 20 世纪 70 年代初出现了一个突变点。武阳岔站没有明显变化，汉水庙站的变化点出现在 1967 年。FDC 分析表明，高、低流量指数均大幅下降。武定河流域所有测站的综合 DHA 均高于 70%，表明日流量的大小、持续时间、频率、时间和变化率变化很大。IC 值和 RI 与 DHA 密切相关，这表明 DHA 受到土地利用变化和大坝/水库建设的高度影响，对土地利用变化更为敏感（p<0.01）。本研究为了解水土保持措施对水文状况的影响提供了很好的见解。
