【作者】 李小冰；

【导师】 蔡焕杰；

【作者基本信息】 西北农林科技大学 ， 农业水土工程， 2010， 硕士

【摘要】 近年来,秃尾河流域国民经济实现了快速增长,农业经济全面发展,工业生产突飞猛进,秃尾河作为重要的水源地,支撑着流域的经济发展,其作用和地位日益突出。因此研究秃尾河流域的径流特征,建立适合流域的水文模型,对于了解该地区的水文水资源状况、预测水文物理过程、合理利用水资源,以及解决相关的生态和经济问题有着重要的理论意义和现实意义。本文选择SWAT分布式水文模型,以GIS为手段,充分考虑当地气候、地形、土地利用、土壤等多种因素的时空分布,建立了秃尾河流域空间数据库、气象数据库、土地利用数据库、土壤属性数据库。通过对数字高程图DEM地形分析,提取流域数字水系,对流域进行离散化,确定子流域划分水平和水文响应单元生成水平。对SWAT模型参数敏感性进行分析,应用秃尾河高家川水文站1977-1984年实测径流资料进行率定,1985-1989年实测径流资料进行验证,结果表明校准期和验证期年径流模拟误差都较小,相关系数( R 2)均0.8以上,模型效率系数(Ens)均在为0.7以上;校准期和验证期月径流模拟误差也都较小,相关系数( R 2)均0.75以上,模型效率系数(Ens)均在0.65左右,一般认为SWAT模型的模拟结果期望值在0.6左右就表明模型很好地概化了研究区的参数,比较准确地描述了研究区的水文过程,因此SWAT模型适用于秃尾河流域。基于以上结果,本文建立了5种不同土地利用/覆被情景和24种假定气候情景,模拟结果表明,随着林、草覆盖率的增加,秃尾河流域径流呈减少趋势,林、草对径流调蓄有一定的作用;林地覆盖率对径流量的影响明显大于草地。在未来情景下,秃尾河流域若发生生态破坏,进行生态修复时,植树造林对于涵养水分和消减径流量的效果要比种植草地好;在假定的24种气候情景中,使径流量增加最多的组合情景是S 21,即P增加20%,T减少2℃,这是对秃尾河流域径流增加最有利的组合情景;使径流量减少最多的是情景S 5,即P减少20%,T增加2℃,这是对秃尾河流域径流量最不利的组合情景。更多还原

【Abstract】 In recent years, the Tuwei Watershed national economy realized the swift growth. The agricultural economy realized full scale development, and the industrial production made great progress by leaps and bounds. Tuwei River supporting the basin economic development took an important place of water resource, and its function and status were prominent day by day. Therefore, carrying out the research on the distributional hydrology model of Tuwei Watershed and establishing the suitable the hydrology model, is helpful to understand the local hydrology water resources condition, forecast hydrology physical process and use water resources reasonablely, which have the important theory and practical significanc for the solution of related ecological question and economic problem.This article chose the distributional hydrology model SWAT through GIS, considered fully the factor’s space and time distributions of local climate, terrain, landuse, soil and so on, established the spatial databases, the meteorological database, the landuse database, the soil attribute database in Tuwei Watershed. This article analysised terrain through the digital elevation chart DEM, extracted basin digital river system, discretized the watershed , and finally determined the sub-watershed and the hydrology response unit division level.This article analysed parameter sensitivity of the SWAT model , calibrated parameter through Gao Jiachuan hydrologic station actual runoff material from 1977 to 1984,validated parameter through actual runoff material from 1984 to 1989,and during both indication time and calibration time the result showed that: the simulation error of actual runoff simulation is very small, the correlation coefficient is above 0.8, the model efficiency coefficient is above 0.7; the simulation error of monthly runoff simulation is also very small, the correlation coefficient is above 0.75, the model efficiency coefficient is about 0.65.The SWAT model’s exploiter believed that the expected value of the model is about 0.6,which indicated that the model expressed the research area parameter accurately, and described research area hydrology process, therefore, the SWAT model is suitable for the Tuwei watershed.Based on the above result, this article has established 5 different landuse scene and 24 kinds of hypothesis climate scene. The simulation result indicated that along with the forest and grass covering’s rate increase, the Tuwei watershed runoff assumes the reduction tendency, so the forest and grass has certain function to regulation and storage of runoff; The influence of forest land covering rate is bigger than grass obviously to the amount of runoff. Under the future scene, if Tuwei watershed has the ecological damage, when people carries on the repairment, the afforestation is better to self-control moisture and discrease runoff than planting grass; in 24 kinds of hypothesis climate scene, S 21 is making the amount of runoff increase most combination scenes, namely P increases 20%, T reduces by 2℃,which is increased the most advantageous combination scene to the Tuwei River basin runoff; The one who causes the amount of runoff to reduce most is the scene S 5, namely P reduces 20%, T increases by 2℃, which is the most disadvantageous combination scene to the Tuwei watershed amount of runoff.更多还原