气候变化和人类活动对灞河流域输沙量影响的定量评估

采用小波分析法、累积距平法分析了灞河流域输沙量和降水量的变化趋势,应用累积量斜率变化率比较法分析了不同时期气候变化和人类活动在灞河流域输沙量变化中的相对贡献率。结果表明:灞河流域输沙量存在1988年和2002年两个突变点;以1960—1987年为基准期,1988—2001年降水量和人类活动在灞河流域输沙量减小中的贡献率分别为12.22%和87.78%,2002—2012年降水量和人类活动在灞河流域输沙量减小中的贡献率分别为6.56%和93.44%。

Quantitative evaluation on impact of climate change and human activities on sediment discharge in Bahe River Basin

Taken the Bahe river basin as the research object, the wavelet analysis method and the cumulative anomaly analysis were employed to analyze the variation trends of the sediment discharge and precipitation. It is revealed that the year 1988 and 2002 are two mutational points for the sediment discharge variation. The comparative method of the slope changing ratio of cumulative quantity was adopted to analyze the contributions of climate change and human activity to sediment discharge in different time periods. The results were obtained by taking 1960-1987 as the baseline period without considering the influence of evapotranspiration. It shows that the contribution rates of precipitation and human activities to the decreased sediment discharge were 12.22% and 87.78% from 1988 to 2001, and changed to be 6. 56% and 93. 44% from 2002 to 2012, respectively. The present study reveals the changing trend of sediment discharge of the Bahe river basin during 1960-2012 and the contribution rates of the main influencing factors, which is of great importance to the water loss and soil erosion control in the future.