Flood Laws of Sector and Pinnate Watersheds with Different Rainstorm Conditions
To investigate influences of uneven spatial and temporal distribution of rainfall processes on river runoffs,tak-ing the Yi River and the Shu River watersheds as examples,flood laws of flood control stations under different rainstorm conditions were obtained by using instantaneous unit line method and Muskingum method to calculate flood flows of 3 d characteristic rainstorms with recurrence interval of 10,20,50 a and 2019 typhoon"Lekima"rainstorm in the two water-sheds.The results show that in sector watersheds,the flood confluence is concentrated prone to flood.In pinnate water-sheds,the flood of each tributary interlaces into the main stream.The nearer water flows away first and the farther water flows away later.The flood is moderate,and the flood control pressure of the Yi River is thus greater than that of the Shu River.In Yi-Shu River watershed,under the same rainfall amount conditions,Linyi station is more likely to form large flood peaks during the rainfall process from north to south.Xiewu station,Shilayuan station,and Chonggou station are more likely to form large flood peaks during the rainfall process from south to north.Juxian station is located in the upper reach of the Shu River,and the control watershed contains multiple tributaries and three reservoirs.The watershed shape is sector watershed in the Shu River watershed belong to pinnate watershed,which is characterized by concentrated flood confluence.The flood control pressure of Juxian station located in the Shu River is greater than that of other stations located in the Shu River.When a large-scale synchronous rainfall process occurs in the Shu River watershed,Juxian station is more likely to form a large flood peak.
flood control and disaster reductionflood peak flowinstantaneous unit line methodMuskingum methodwatershed shape
NETL
NSTL
万方数据
