星云湖流域水土流失估算及水文模拟的GIS应用

发布时间：2018-04-10 15:13

本文选题：USLE + SWAT　；参考：《昆明理工大学》2017年硕士论文

【摘要】：土壤侵蚀作为一种非点源污染,其流失土壤中所含养分进入水体,将会增加水体富营养化的风险,因此引起了社会各界的广泛关注。近年来,随着遥感(RS)、地理信息系统(GIS)和全球定位系统(GPS)技术的迅速发展和土壤侵蚀机理研究的不断深入,使用RS和GIS技术和土壤侵蚀评价模型相结合来精确评价土壤侵蚀的方法越来越受到人们的重视。在云南九大高原湖泊中,以滇池、星云湖为代表的高原湖泊成为我国湖泊受人类干扰程度最大、湖泊水质下降最为严重、富营养化问题最突出的地区之一。星云湖是江川县工农业发展重要的水资源供应源,对星云湖流域生态环境以及经济的发展起着关键的作用,星云湖的水质每况愈下,影响着该区域的生态完整性和经济的可持续发展。本文以星云湖流域作为研究对象,基于流域的土地利用、植被、土壤、地形、气象、水文等基础空间和属性数据,运用GIS技术,通过结合USLE模型模拟流域土壤侵蚀状况及其分布状况;同时,结合SWAT模型,模拟了星云湖流域径流量和非点源氮磷负荷量。主要结论如下:1.分析了星云湖流域多年的土壤侵蚀状况及其空间分布。星云湖流域2014年土壤侵蚀总面积为221.09km2,平均侵蚀模数为34.07t/km2.a 土壤侵蚀主要以中度及中度侵蚀以下为主,占总侵蚀面积的96.67%,强烈侵蚀较少,主要分布在流域北部。2.获取了星云湖流域多年径流量和非点源氮磷负荷量。模型率定期(2012-2013年)和验证期(2014年)的模拟月径流量与实测月径流量的线性回归方程的决定系数(R2)分别为0.87、0.88;非点源氮磷的率定期和验证期的R2分别为0.89、0.83。模拟效果较好,适用于星云湖流域的径流量和非点源氮磷的模拟。3.利用GIS技术,揭示了星云湖流域土壤侵蚀和面源污染与主要土壤侵蚀因子的关系。(1)在不同的坡度上,土壤侵蚀主要发生在15°～35°之间,强烈侵蚀主要发生在35°以上;(2)不同的土地利用类型之间的土壤侵蚀状况有较大差别。其中,林地侵蚀面积最大,但大都是中度及以下侵蚀。(3)非点源污染主要集中在第四子流域,主要原因是该子流域径流量最大,且农用地面积最大。
[Abstract]:As a kind of non-point source pollution, soil erosion will increase the risk of eutrophication because of its loss of nutrients from the soil into the water body, which has aroused widespread concern from all walks of life.In recent years, with the rapid development of remote sensing (RS), GIS (Geographic Information system) (GIS) and GPS (Global Positioning system) technology and the deepening of soil erosion mechanism research,More and more attention has been paid to the method of accurately evaluating soil erosion by using RS and GIS technology and soil erosion evaluation model.Among the nine major plateau lakes in Yunnan, Dianchi Lake and Xingyun Lake have become one of the most serious areas where the lake is disturbed by human beings, the water quality of the lake is most serious, and the eutrophication problem is the most prominent.Xingyun Lake is an important source of water resources for the development of industry and agriculture in Jiangchuan County. It plays a key role in the ecological environment and economic development of Xingyun Lake basin, and the water quality of Xingyun Lake is getting worse and worse.Affect the ecological integrity of the region and the sustainable development of the economy.Based on the basic spatial and attribute data of land use, vegetation, soil, topography, meteorology, hydrology and so on, this paper takes Xingyun Lake Basin as the research object, and applies GIS technology.The soil erosion and its distribution were simulated by combining with USLE model, and the runoff and non-point source nitrogen and phosphorus load were simulated by combining with SWAT model.The main conclusions are as follows: 1.The soil erosion and its spatial distribution in Xingyun Lake basin for many years were analyzed.The total area of soil erosion in Xingyun Lake Basin in 2014 was 221.09km2. The average erosion modulus of 34.07t/km2.a was mainly below moderate and moderate erosion, which accounted for 96.677cm of the total erosion area, and the strong erosion was less, mainly distributed in the northern part of the basin.The runoff and non-point source nitrogen and phosphorus load in Xingyun Lake Basin were obtained.The determinant coefficient of the linear regression equation of simulated monthly runoff and measured monthly runoff is 0.87 ~ 0.88 for the model rate (2012-2013) and R _ 2 for verification period (2014), respectively, and R ~ (2) for non-point source nitrogen and phosphorus rate periodic and validation period is 0.89 ~ 0.83, respectively.The simulation effect is good, which is suitable for the simulation of runoff and non-point source nitrogen and phosphorus in Xingyun Lake basin.Using GIS technique, the relationship between soil erosion and non-point source pollution and main soil erosion factors in Xingyun Lake basin was revealed. In different slopes, soil erosion mainly occurred in the range of 15 掳to 35 掳.Strong erosion occurred mainly in the area above 35 掳, and there was a great difference in soil erosion among different land use types.Among them, the area of forest land erosion is the largest, but most of the erosion is moderate or below. The non-point source pollution is mainly concentrated in the fourth sub-basin, the main reason is that the runoff of the subbasin is the largest, and the area of agricultural land is the largest.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S157;P208

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