摘要
西南山区中小河流分布广泛,洪水大多汇流时间短,洪峰大,因此携带泥沙破坏力强。以川西南典型山区河流——寿溪河为例,基于HEC-HMS模型中的MUSLE算法构建流域产沙模型。即,首先采用该模型通过产、汇流及河道洪水演算过程对场次降雨进行洪水预报,再依据洪水预报结果基于MUSLE公式进行流域产沙模拟。该公式通过计算流域的产沙过程和泥沙输移过程,预测单场降雨下面蚀和细沟侵蚀的情况。主要涉及到的计算因子包括降雨强度、下垫面情况、地形状况及土壤状况,因此,研究从以上4个方面对流域产沙进行了相关性分析。结果表明:降雨强度与流域产沙量有正相关关系,泥沙区间变化率在趋于初始降雨强度时达到峰值;在计算范围内,当覆被因子减小为原来的20%时,泥沙的区间变化率达到50%,增大为原来的180%时,区间变化率仅为13%;覆被因子和地形因子变化率相同的情况下,流域产沙的变化情况完全相同,在平缓短坡上,下垫面的植被覆盖越密集,流域产沙越少;对流域土壤状况来说,土壤中细颗粒占比越大,流域产沙量越多。
Medium and small rivers are widely distributed in the mountainous regions of Southwest China,of which the flood confluence time is short and flood peak is large with strong destructive power from the flood-carried sediment.By taking a typical river in Southwest Sichuan—Shouxi River as the study case,a watershed sediment yield model is established with the MUSLE algorithm of HEC-HMS model.Namely,the flood forecast is made for rainfalls through the flood yield,confluence and river flood routing process with the model at first,and then the watershed sediment yield is simulated by means of MUSLE formula in accordance with flood forecast result.The surface erosion and rill erosion under a single rainfall are predicted through calculating the sediment yield process and sediment transport process within the watershed with the formula,for which the main involved calculation factors include rainfall intensity,underlying surface condition,topographic condition and soil condition,and then the watershed sediment yield is correlatively analyzed from the four aspects in the study.The results show that a positive correlative relationship is there between rainfall intensity and sediment yield,while the interval changing rate of sediment reaches the peak value when tending to the initial rainfall intensity.Within the calculation range,when the coverage factor is reduced to 20%of the original,the interval changing rate of sediment is to reach to 50%and when it increases to 180%of the original,the interval changing rate is only to be 13%.When the changing rate of coverage factor and topographic factor are the same,the changes of the sediment yield within the watershed are exactly the same,while the denser the vegetation coverage for underlying surface is,the less the watershed sediment yield is to be on gentle short slope.For the soil condition in the watershed,the larger the proportion of the fine particles in soil is,the more sediment yield in the watershed is to be.
作者
王瑞滢
张大帅
周末
肖鸿
覃光华
WANG Ruiying;ZHANG Dashuai;ZHOU Mo;XIAO Hong;QIN Guanghua(College of Water Resource&Hydropower,Sichuan University,Chengdu 610065,Sichuan,China;Sichuan University Engineering Design and Research Institute Co.Ltd,Chengdu 610065,Sichuan,China;State Key Laboratory of Hydraulics and Mountain River Engineering,Sichuan University,Chengdu 610065,Sichuan,China)
出处
《水利水电技术（中英文）》
北大核心
2022年第5期119-127,共9页
Water Resources and Hydropower Engineering
基金
国家重点研发计划项目(2019YFC1510701)
国家自然科学基金面上项目(51879172)。
作者简介
王瑞滢(1998-),女,硕士研究生,研究方向为水文预报。E-mail:2856851871@qq.com;通信作者:覃光华(1975-),女,教授,博士,研究方向为水文预报。E-mail:ghqin2000@163.com。
