【作者】 宋扬；

【导师】 汤洁； 苏伟；

【作者基本信息】 吉林大学 ， 工程硕士（专业学位）， 2018， 硕士

【摘要】 在流域水文的整个循环中,泥沙、降雨和下垫面等环境因子都在水文变化过程中对径流变化起着重要的作用。随着人类对自然水循环的影响日益加剧,其中土地利用变化更是直接影响着水文循环过程中植物截留、填洼、蒸散发及下渗等过程,并最终直接影响着径流变化。本文选取辽河干流铁岭段流域,铁岭市行政单元为研究样区,在利用源-汇理论预测未来土地利用类型的变化的同时,并利用SWAT模型对流域径流的变化过程进行模拟,以揭示土地利用变化与水文过程的响应关系。本研究可为流域未来的水资源合理开发利用提供相关建议。本文研究内容包含以下几个部分:(1)土地利用变化研究方面。主要是利用Landsat系列卫星TM影像,利用ENVI5.1软件进行遥感解译,分析研究区1990年、1995年、2000年、2005年、2010年和2015年六期土地利用变化的趋势,并利用源-汇理论的开展研究区未来土地利用合理调整的研究。(2)土地利用优化调整措施。针对铁岭市规划要求与引起的水文响应变化,未来应该优化土地利用格局,增加林地面积66.58km~2,同时保障城镇化发展需要新增建设用地32.58km~2。(3)模型建立和率定方面。为探索研究区径流变化,运用SWAT模型软件构建研究区径流变化模型,选取1991-2005年径流数据进行径流参数年尺度及月尺度的率定,并基于2006-2013年及月尺度的径流数据对成果进行验证。结果表明在率定期和验证期内各站月均径流深相对误差均小于15%,基本满足小于20%的要求,各站决定系数和纳什效率系数均大于0.78,均满足模型的精度要求,证明SWAT模型模拟流域的径流效果较好,适用于辽河干流铁岭段流域的径流等水文模拟。(4)土地利用变化引起的水文响应研究。通过源-汇理论预测未来土地利用,利用未来土地利用作为输入条件,通过率定好的SWAT径流变化模型对未来径流的模拟,结果表明年径流量有所下降,多年平均径流量减少了1.56m~3/s,径流量变化幅度为2.114%。更多还原

【Abstract】 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%.更多还原