摘要
基于河龙区间12个雨量站点1957—2011年降雨日数据及输沙量年数据,采用滑动平均、线性倾向估计、Mann-Kendall非参数检验、累计距平、双累积曲线等方法,分析了河龙区间近55 a降雨侵蚀力和输沙量的动态变化过程以及二者之间的相关关系,定量评估了降雨侵蚀力变化和人类活动对河龙区间输沙量变化的影响及贡献率。结果表明,河龙区间近55 a降雨侵蚀力在378.1~2 324.6 MJ·mm/(hm2·h·a)之间变化,其平均值为1 319.7 MJ·mm/(hm2·h·a);整个研究期内降雨侵蚀力呈不显著减小趋势,年均减小量为9.7 MJ·mm/(hm2·h·a)。近55 a降雨侵蚀力变化过程可划分为3个阶段:1957—1974年为快速下降阶段,其下降率为83.7%;1975—1999年为缓慢下降阶段,其下降率为66.6%;2000—2011年为缓慢回升阶段,其上升率为42.7%。以1957—1969年降雨侵蚀力为基准,20世纪70、80、90年代以及21世纪前12 a降雨侵蚀力分别减小了15.9%、19.5%、27.5%和22.7%。河龙区间近55 a输沙量变化介于(0.09~21.37)亿t之间,其平均值为5.6亿t。整个研究期内输沙量呈极显著的下降趋势,其下降速率为0.19亿t/a。以1957—1969年输沙量为基准,20世纪70、80、90年代以及21世纪前12 a输沙量分别减少了27.3%、64.1%、54.8%和88.7%。经Mann-Kendall非参数检验法和累计曲线法综合判定,1979年为河龙区间输沙量突变年份。输沙量与降雨侵蚀力具有极好的线性相关性。通过建立二者双累积曲线方程,计算得出20世纪80、90年代和21世纪前12 a降雨侵蚀力变化对输沙量变化的贡献率分别为22.6%、44.3%和19.0%,而人类活动对输沙量变化的贡献率分别为77.4%、55.7%和81.0%,人类活动对输沙量变化的影响程度较大。1980—1989年和2000—2011年具有基本相同的降雨侵蚀力条件,但后者的输沙量却比前者减少67.6%,表明2000—2011年河流输沙量的变化主要由人类活动引起,人类活动每年减少输沙量2.5亿t。
The dynamic change of rainfall erosivity and river sediment discharge as well as the correlation between river sediment discharge and rainfall erosivity were analyzed based on daily rainfall data and yearly sediment discharge of 12 rainfall stations located in He-Long reach of the Yellow River from 1957 to 2011. Meanwhile,the impact and contribution of rainfall erosivity changes and human activities on the river sediment discharge changes were quantitatively evaluated. The main methods used were the moving average,linear trend estimation,Mann-Kendall nonparametric test,cumulative departure curve and double mass curve. The results showed that rainfall erosivity in He-Long reach from 1957 to 2011 shiftedfrom 378. 1 MJ · mm /( hm2· h · a) to 2 324. 6 MJ · mm/( hm2· h · a) with a mean of1 319. 7 MJ·mm /( hm2·h·a),and rainfall erosivity did not exhibit significant downtrend. The decrement of rainfall erosivity per year in 1957—2011 was 9. 7 MJ·mm /( hm2·h·a). The changing trend of rainfall erosivity was divided into three stages during past 55 years in He-Long reach,which consisted of a rapid declining trend from 1957 to 1974,a slow decreasing trend from 1975 to 1999,and a slow increasing trend from 2000 to 2011. The declining rates of the first and second stages were 83. 7% and 66. 6%,respectively,and the increasing rate of the third stage was 42. 7%. With rainfall erosivity in 1957—1969as a reference,rainfall erosivities in the 1970 s,1980s,1990 s and the first 12 years of the 21 st century were decreased by 15. 9%,19. 5%,27. 5% and 22. 7%,respectively. The river sediment discharge in He-Long reach from 1957 to 2011 shifted from 9 × 106 t to 2. 14 × 109 t with a mean of 5. 60 × 108 t,and river sediment discharge showed highly significant downtrend. The decrement of river sediment discharge in 1957—2011 was 1. 9 × 107 t / a. With river sediment discharge in 1957—1969 as a reference,river sediment discharges in the 1970 s,1980s,1990 s and the first 12 years of the 21 st century were decreased by 27. 3%,64. 1%,54. 8% and 88. 7%,respectively. The Mann-Kendall nonparametric test and the cumulative departure curve showed that the abrupt change of river sediment discharge appeared in 1979.There was a better linear correlation between river sediment discharge and rainfall erosivity. According to the double mass curve equation,the contributions of rainfall erosivity to the river sediment discharge changes in the 1980 s,1990s and the first 12 years of the 21 st century were 22. 6%,44. 3% and19. 0%,respectively; while the contributions of human activities to the river sediment discharge changes were 77. 4%,55. 7% and 81. 0%,respectively. Therefore,the impact of human activities on the river sediment discharge changes was dominated. Although rainfall erosivity in two periods of 1980—1989 and2000—2011 was similar,river sediment discharge in 2000—2011 was decreased by 67. 6%,compared with that in 1980—1989. Thus,the river sediment discharge changes were mainly caused by human activities and the decrement of river sediment discharge per year caused by human activities was 2. 5 ×108t in 2000—2011.
出处
《农业机械学报》
EI
CAS
CSCD
北大核心
2016年第2期185-192,207,共9页
Transactions of the Chinese Society for Agricultural Machinery
基金
水利部公益性行业科研专项(201201083)
关键词
河龙区间
输沙量
降雨侵蚀力
人类活动
贡献
He-Long reach
sediment discharge
rainfall erosivity
human activity
contribution