基于SWAT模型的秦皇岛地区非点源污染模拟研究

发布时间：2018-11-10 07:11

【摘要】：当今社会水环境污染的严重性已受到国内外普遍关注,水污染问题通常分为点源污染和非点源污染两种。在点源污染的控制能力逐步提升并得到有效治理的情况下,非点源污染成为了水源污染的主要污染源。特别是进入21世纪,中国农业非点源污染对水体富营养化的影响将进一步加剧,农业和农村发展引起的水污染将成为中国可持续发展的最大挑战之一。影响非点源污染的因素很多,其中土地利用/覆被变化是造成非点源污染的关键影响因素,它通过影响径流量、泥沙量,进而影响着非点源污染的产生及其营养物质的迁移转化的过程,从而影响非点源污染的氮磷负荷量。秦皇岛依山傍海,境内水系丰富,分属滦河与冀东沿海河流两大水系,是华北地区水资源相对丰富的地区。但近年来该地区水资源环境呈现污染加剧的趋势,水环境的安全度相对较低,目前水环境点源污染的问题得到了一定的控制和解决,非点源污染的危害还没有完全表现出来,但从发展的角度看,有必要对该地区的非点源污染进行研究,为该地区非点源污染的防治和治理提供一定科学依据。因此本文在重点考虑非点源污染的基础上,以秦皇岛地区为研究对象,探讨了不同的土地利用方式对非点源氮磷污染的影响。主要包括以下内容:(1)在实地调查的基础上,进行数据收集和整理,根据秦皇岛地区主要河流流域、水质监测数据、水文站点资料、雨量站点资料、气象站资料等数据,依托ArcGIS等软件构建SWAT模型的空间数据库和属性数据库。(2)以空间数据和属性数据为基础,运用SWAT模型,对秦皇岛地区的径流、泥沙、非点源污染总氮、总磷负荷进行模拟。通过参数敏感性分析,获得径流、泥沙、总氮和总磷的较为敏感的参数,进行模型参数的校准,并对模型的有效性和适用性进行验证,构建模型适用性评价指标Re、R2和Ens都在要求的范围内的SWAT模型。(3)基于2000年、2005年、2010年和2014年秦皇岛地区土地利用/覆被数据,通过空间叠加分析流域土地利用/覆被的时空变化特征,对秦皇岛地区土地利用/覆被变化进行分析。(4)根据四个不同时期的土地利用类型图得到各时期土地利用类型之间的面积和比例的变化,并运用SWAT模型分别添加四期不同的土地利用类型图进行研究区径流、泥沙、非点源总氮、总磷负荷的模拟,分析土地利用变化对径流、泥沙、非点源污染总氮、总磷负荷的时空变化影响情况。(5)对比研究时段内非点源污染总氮、总磷负荷量与径流量、泥沙量时空变化发现,四种情景的的时空变化情况相对一致,说明径流量和产沙量是总氮总磷负荷的关键制约因素。径流量大,携带的溶解态的氮磷元素就多,泥沙量大,携带的吸附态的氮磷元素负荷就大,从而使总氮总磷负荷增大。(6)进行土地利用情景预测,运用SWAT模型对三种土地利用情景下的非点源污染的氮磷负荷进行模拟,在模拟结果的基础上定量分析三种不同预测情景导致不同土地利用方式对秦皇岛地区非点源污染氮磷元素的时空影响。
[Abstract]:The severity of water pollution in today's society has been paid close attention at home and abroad, and the water pollution problem is usually divided into point source pollution and non-point source pollution. The non-point source pollution is the main pollution source of the water source pollution in the case of the gradual improvement of the control ability of point source pollution and the effective treatment. Especially in the 21st century, the effects of non-point source pollution on the eutrophication of the water body will be further increased, and the water pollution caused by the development of agriculture and rural areas will become one of the biggest challenges for China's sustainable development. The factors that affect the non-point source pollution are many, among which the land use/ cover change is the key influencing factor of non-point source pollution, and it influences the process of the generation of non-point source pollution and the migration and transformation of the nutrient substances by influencing the runoff and the amount of the sediment, so as to influence the nitrogen and phosphorus load of the non-point source pollution. Qinhuangdao is rich in water system, which is a relatively rich area of water resources in North China. However, in recent years, the situation of water resources in the area has become more and more serious, and the safety of the water environment is relatively low. At present, the problem of point source pollution in the water environment has been controlled and solved, and the harm of non-point source pollution has not been shown completely, but from the viewpoint of development, It is necessary to study the non-point source pollution in the area and provide a scientific basis for the prevention and treatment of non-point source pollution in the area. Therefore, on the basis of the consideration of non-point source pollution, this paper discusses the effects of different land-use methods on the pollution of non-point source, nitrogen and phosphorus in the area of Qinhuangdao as the research object. It mainly includes the following contents: (1) On the basis of field survey, data collection and sorting are carried out, according to the data of main river basin, water quality monitoring data, hydrological station point data, rainfall station point data and weather station data in Qinhuangdao area, The spatial database and the property database of SWAT model are constructed with the software of ArcGIS. (2) Based on spatial data and attribute data, SWAT model is applied to simulate the total nitrogen and total phosphorus load of runoff, sediment and non-point source pollution in Qinhuangdao area. Through the parameter sensitivity analysis, the more sensitive parameters of runoff, sediment, total nitrogen and total phosphorus are obtained, the model parameters are calibrated, and the validity and applicability of the model are verified. The model suitability evaluation indexes Re, R2 and Ens are all within the required scope. (3) Based on the data of land use/ cover in Qinhuangdao area in 2000, 2005, 2010 and 2014, the spatial and temporal change of land use/ cover in Qinhuangdao area is analyzed by the spatial superposition analysis. and (4) according to the land-use type map of the four different periods, the change of the area and the proportion between the land-use types of each period is obtained, and the SWAT model is used for respectively adding four different land-use type maps to study the simulation of the total nitrogen and the total phosphorus load of the area runoff, the sediment, the non-point source total nitrogen and the total phosphorus load, The influence of land-use change on total nitrogen and total phosphorus load of runoff, sediment and non-point source pollution was analyzed. (5) The time-and-spatial variation of total nitrogen, total phosphorus load and runoff and sediment volume of non-point source pollution in the comparative study period were found to be relatively consistent with the time-and-spatial variation of the four scenarios, indicating that the runoff and sediment concentration are the key factors of total nitrogen total phosphorus load. and the total nitrogen total phosphorus load is increased. (6) using the SWAT model to simulate the nitrogen and phosphorus load of the non-point source pollution in the three land use scenarios, The spatial and temporal effects of different land-use patterns on the nitrogen and phosphorus elements of non-point source pollution in Qinhuangdao area were quantitatively analyzed on the basis of the simulation results.
【学位授予单位】：河北师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X52

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