Study On Flood Loss Assessment And Disaster Reduction Strategies In The Middle And Lower Reaches Of The Yellow River In Henan Province

Yellow River,which is famous for being a perched river running way beyond its local grounds,is the largest among all the rivers that are richest with sediment in the world.Its downstream is typically seriously blocked by sediment,which causes the riverbed's height to be accumulated rapidly,and thus the River's trials to be unstable and constantly changing,as well as its flood carrying capacity deteriorating every year.Therefore,one of the most urgent and important problems lies on how to both scientifically evaluate damages cuased by the Yellow River floods and propose effective disaster prevention strategies.This paper proposes a model on assessing the damages caused by floods by starting from the causality between the society's economic development and the damages caused by floods,with the support of GIS technology.In addition,the paper also shows simulation results of the evaluation on the damages caused by the floods for areas in the middle and lower reaches of the Yellow River in Henan Province,as well as detailed and strategic advices on disaster preventions based on the evaluation results,serving the purpose of providing theoretical guidance and data supports for the formulation of the local disaster prevention policies.The research procedures are as the following: Firstly,investigate into the detailed socio-economic and land usage status for the areas affected by floods,then establish a disaster assessment database,which consists of socio-economic development status and land usage situation;Secondly,settle down the basic standards those assessments follow,and effectively simulate the situations of the flood-disaster-affected areas.Thirdly,through the investigations of the real situations of flood damage in areas around the middle and lower reaches of the Yellow River in Henan Province,establish a systematic assessment model,and testing the accuracy of the model by comparing between the actual disaster information recorded from year 1996's flood disaster and the simulated log-out data that has the simulation log-in data sample originated from the same event.Fourthly,predict the study area's economic situation in 2020 as well as the total loss to be caused by floods by using the established disaster damage assessment model with input of floods information in 1996 and by according to its latest(year 2018's)land use information.Fifthly,formulate corresponding flood prevention and mitigation strategies based on the assessment results.Here are some Initial results:(1)Simulated inundation area of the study area in 1996 is 160,800 hectares,while the actual inundation area was 165,680 hectares,which resulted in a relative error of 2.945%.In comparison with the actual inundated cultivated area of 130,800 hectares,the estimated area of the submerged cultivated land is 127,133 hectares with a relative error of 2.78%.(2)The main type of the submerged lands in the study area is cultivated land,followed by rural settlement land,and other land usage types are relatively small.(3)The damages cuased by flood disaster imply some certain geographical distribution pattern,meaning the lands on the left bank of the Yellow River are normally seriously damaged,while the lands on the right bank of the Yellow River are relatively less damaged;for instances,Fan County,Wuzhi,Puyang,Yuanyang,Changyuan,Taiqian and other places on the left bank of the River suffer from more serious damages;while Gongyi,Kaifeng,Xingyang,Zhengzhou,Lankao,Zhongmou,and other places on the right bank of the River are lightly damaged..(4)Flood disasters can cause certain degree of damages to areas located around the middle and lower reaches of the Yellow River in Henan Province,among which are mainly agricultural economic losses and family property losses.By predicting the total loss of floods in 2020,the agricultural economic loss is 9.02 billion yuan,occupying 39% of the total direct economic losses;the family property loss is 12.579 billion yuan,occupying 55% of the total direct economic losses.(5)The research proofs the flood assessment method based on GIS technology has good feasibility,and the model evaluation results certainly have some reliability.It contains certain reference values for the economic development,flood control,and formation of disaster prevention and land usage strategies for areas located around the middle and lower reaches of the Yellow River in Henan Province.