极端降雨事件对南方红壤区径流和输沙的影响——基于赣江支流濂江上游流域的长序列分析(1984-2020年)  

Effects of extreme rainfall events on runoff and sediment in the southern red soil area:A long series analysis based on the Upper Lianjiang River of Ganjiang River(1984-2020)

作　　者：赵利祥 郭忠录[2] 聂小飞 廖凯涛 郑海金 Zhao Lixiang;Guo Zhonglu;Nie Xiaofei;Liao Kaitao;Zheng Haijin(Jiangxi Academy of Water Science and Engineering,Nanchang 330029,P.R.China;College of Resources and Environment,Huazhong Agricultural University,Wuhan 430070,P.R.China;Key Laboratory of Soil Erosion and Prevention in Jiangxi Province,Nanchang 330029,P.R.China)

机构地区：[1]江西省水利科学院,南昌330029 [2]华中农业大学资源与环境学院,武汉430070 [3]江西省土壤侵蚀与防治重点实验室,南昌330029

出　　处：《湖泊科学》2023年第6期2133-2143,共11页Journal of Lake Sciences

基　　金：国家自然科学基金项目(42267058);江西省科技厅重大科技研发专项“揭榜挂帅”制项目(20213AAG01012);江西省水利厅科技计划项目(202124ZDKT25)联合资助。

摘　　要：为探究极端降雨对南方红壤区流域水沙的影响,本文基于江西省鄱阳湖水系赣江上游濂江流域1984—2020年逐日降雨量、径流量和输沙量数据,使用95百分位法计算极端降雨,并采用最小事件间隔时间法分割降雨事件,综合应用Pettitt检验和线性回归方法对水沙突变、影响因子进行定量分析。结果表明:(1)发生极端降雨事件的时期是流域泥沙输出的关键时期,极端降雨对输沙量的贡献率达85.58%~87.79%,而对径流量的贡献为38.33%~43.42%。(2)在极端降雨情景下,年径流量从1984—1995年的209.21×10^(6)m^(3)下降到1996—2020年的165.23×10^(6)m^(3),而年输沙量从1984—1995年的3.65×10^(4)t增加到1996—2020年的12.8×10^(4)t,相比于1984—1995年,1996—2020年的极端降雨所产生的径流量和输沙量占比有缩小趋势,分别表现为从43.42%到38.33%和从87.79%到85.58%。(3)极端降雨情景下影响流域水沙变化的主要因子是降雨量,其标准化回归系数为0.39~0.57,而普通降雨情景下水沙变化主要受前期降雨量的影响,其标准化回归系数为0.10~0.29。(4)仅对极端降雨而言,相比于1984—1995年,1996—2020年前期降雨量对径流量和输沙量的标准化回归系数均有所上升,分别从0.33提高到0.36、从0.12提高到0.17,即前期降雨量的作用在“径流减少,输沙增多”时期对水沙变化的影响更明显。因此,在制定流域管理策略时应重视极端降雨对水沙变化的影响,以确保措施切实可行。This paper explored the influence of extreme rainfall on flow and sediment in the southern red soil region based on the daily rainfall,runoff and sediment discharge data of from 1984 to 2020,in the Upper Ganjiang Basin of the Lake Poyang system in Jiangxi Province.The 95 th percentile method was used to isolate extreme rainfall,and the minimum inter-event time method was used to split rainfall events.The Pettitt test and linear regression method were used to analyze the abrupt change and influencing factors of flow and sediment.The results showed that:(1)The period of extreme rainfall events was the critical period of sediment output in the basin,and the contribution of extreme rainfall to sediment was 85.58%-87.79%,while the contribution to runoff was 38.33%-43.42%.(2)Under the extreme rainfall scenario,the annual runoff decreased from^(2)09.21×10^(6)m^(3)in 1984-1995 to 165.23×10^(6)m^(3)in 1996-2020,while the annual sediment increased from^(3).65×10^(4)t in 1984-1995 to 12.8×10^(4)t in 1996-2020,and compared with 1984-1995,the percentage of runoff and sediment generated by extreme rainfall in 1996-2020 has a decreasing trend,respectively showed from 43.42%to 38.33%and from 87.79%to 85.58%.(3)Rainfall was the main factors influencing flow-sediment changes in the basin under extreme scenarios,with standardized regression coefficients of 0.39-0.57.The flow-sediment changes under the normal rainfall scenario was mainly influence by the antecedent rainfall,with standardized regression coefficients of 0.10-0.29.(4)For extreme rainfall only,the standardized regression coefficients of rainfall on runoff and sediment increased from 0.33 to 0.36 and from 0.12 to 0.17,respectively,from 1996 to 2020 compared with 1984 to 1995.It suggested that the effect of antecedent rainfall on flow-sediment change was more significant in the period of“reduced runoff and increased sediment”.Therefore,when formulating basin management strategies,attention should be paid to the influence of extreme rainfall on the flow-sediment ch

关 键 词：最小事件间隔时间法 降雨特征参数 径流量 输沙量 赣江 濂江流域 

分 类 号：S157[农业科学—土壤学] P333[农业科学—农业基础科学]