1956-2018年资江干流径流输沙演变规律与特征分析

Evolution and Characteristics of Annual Runoff and Sediment Transport in the Main Stem of Zijiang River,1956-2018

研究资江径流泥沙演变规律与变异特征,了解资江干流径流变异与输沙量变化情况,为流域水资源可持续利用提供政策建议。根据资江流域干流主要控制站1956-2018年长时间序列径流量和输沙量数据,运用累积距平法、M-K法、集中度与集中期、小波分析法和均值差异T检验法等分析资江年径流量和输沙量的演变规律与特征。结果表明:(1)径流量不同年代时段的变化率-18.2%~25.8%,Z统计值为0.7058,径流量变化趋势不显著;而输沙量减少趋势较为明显,Z统计值为-5.0592,通过信度99%的显著性检验;(2)资江年径流量未发生明显的突变,而输沙量在1995年发生了突变;(3)资江径流存在第一主周期为26a的周期性,输沙量存在第一主周期为34a的周期性规律;(4)资江径流量变化存在1956-1966年、1982-1988年2002-2015年3个少水期,1967-1981年、1989-2001年、2016-2018年3个多水期,输沙量变化存在1956-1976年、1988-1997年2个多沙期,1977-1987年、1998-2018年2个少沙期;(5)径流量集中度为31.8%,输沙量集中度为73.7%,资江径流泥沙年内分配不均匀性特征明显。

Zijiang River is an important tributary of the Dongting River system and the third largest river in Hunan Province.The variation of river runoff and sediment transport is an important aspect of water resource management,agricultural irrigation,flood control and aquatic ecology.Based on the long-term record(1956-2018)of runoff and sediment transport data collected at the primary control station in the main stem of Zijiang River basin,the evolution law and characteristics of the annual runoff and sediment transport in Zijiang River were analyzed by using the cumulative anomaly,M-K method,concentration and centralization,wavelet analysis and T-testing of means.The study will provide scientific reference for the management and sustainable usage of water resource in the main stem of Zijiang River.The results fall into five groups:(1)Trends:The change rate of runoff was in the range of-18.2 to 25.8%,and the value of the Z statistic was 0.7058,indicating no significant trends in runoff variation.Sediment transport has decreasing significantly;the Z statistic value was-5.0592,significant at 99%.(2)Abrupt changes:There was no clear change in the annual runoff,but sediment transport changed abruptly in 1995.(3)Periodicity:There was a period of 26a for water runoff and a periodic law of 34a for sediment transport.(4)Phases:There were three periods of water shortage(1956-1966,1982-1988,2002-2015)and three periods of plentiful water(1967-1981,1989-2001,2016-2018).There were two periods of high sediment discharge(1956-1976,1988-1997)and two periods of low sediment discharge(1977-1987,1998-2018).(5)Concentration and centralization:The concentration of runoff and sediment transport was 31.8%and 73.7%,respectively.The distribution of runoff and sediment within a year was characterized by an uneven distribution.