Response Relationship Between Land Use And Run Off In The Tieling Of The Liaohe River

In the hydrological cycle of a river basin,runoff plays an important role as a carrier in such phenomena as the eutrophication of water bodies,the transport of sediment,heavy metals,and micro-organisms,and the flood process formed by rainfall.With the rapid socio-economic development,human activities have seriously interfered with the land use in the river basin.This directly affects the hydrological sub-processes such as crop retention,land reclamation,evapotranspiration,and infiltration,and then distributes rainfall during rainfall in the basin.Hydrological cycle processes such as production and confluence have important implications.Study the runoff process of the valley under land use change,master the change trend and dominant factors of the runoff process of the river basin,and use the source-sink theory to predict the change process of runoff under the changing conditions of future land use patterns,which can be the future of water and soil resources in the basin.The sustainable development,utilization and protection provide reference.This paper selects the administrative unit of Tieling City,Tieling River Basin,as the research area,and uses the SWAT model as a research platform to simulate the rainfall runoff process of the Tieling section of the Liaohe River.The SWAT model of the basin is calibrated and verified.At the same time,the study of land use changes in different periods of the Tieling section was conducted.The source-sink theory was used to adjust the future land use changes in the study area and simulate the runoff.This article includes the following sections:(1)Land use research.The main use of remote sensing is to use the source-sink theory to conduct research on land use changes in the study area in 1990,1995,2000,2005,2010 and 2015.Finally,a model with a good rate of determination will be used to study the simulation of regional runoff changes under future land use conditions.(2)Land use optimization adjustment measures.In response to changes in hydrological response caused by Tieling City planning requirements,the land use pattern should be optimized in the future to increase the forest land area by 66.58 km~2.At the same time,it is necessary to increase the urban construction area by 32.58 km~2.(3)Model building aspect.In the aspect of water extraction,the fractal theory was used to determine the reasonable cumulative threshold of confluence through the dual indexes of fractal dimension and river network density,and to improve the precision of the simulated river network extraction,thereby improving the accuracy of the establishment of the hydrological model database in basin water system extraction.A database of hydrological simulations in the study area was constructed using data from rainfall,weather,soil and land use interpretation in the basin.Runoff data from1988 to 2013 were selected to verify and validate the runoff results simulated by the SWAT model on the annual and monthly scales.The results show that the monthly average runoff depth relative error of each station is less than 15%regardless of the rate of regularity and verification period,and basically meets the requirement of less than 20%.The determination coefficient and Nash efficiency coefficient of each station are greater than 0.79.Both satisfy the precision requirements of the model,which shows that SWAT model can simulate the runoff effect of the river basin and it is applicable to runoff and other hydrological studies in the Laoha River Basin.(4)Hydrological response due to land use changes in the future.Forecasting future land use through source-sink theory,using future land use as an input condition,and simulating future runoff through a well-established SWAT model,the results show that annual runoff has declined overall,and annual runoff depth has decreased by 1.56m3/s.The change in runoff was 2.114%.