大安市土地利用变化驱动下的降水入渗与土壤水分模拟研究

发布时间：2018-07-26 20:21

【摘要】：随着社会经济的高速发展、人类活动的不断影响,生态水文过程受到了剧烈的影响。土地利用/土地覆被变化(LUCC)是人类复杂的活动中较为典型的影响着生态水文环境的重要因素,也是当今社会的研究热点。作为生态水文研究内容中的重要组成部分,地下水和土壤水对于土地利用变化的响应也十分明显,而降水入渗是地下水补给的重要形式,对地下水有着十分重要的影响。大安市位于松嫩平原腹地,属于我国的生态脆弱区,多年干旱少雨,土壤盐碱化、沙化、荒漠化问题日益加重,地下水位下降等生态问题越来越严重。本文以大安市为研究对象,将3S技术与实验和模型模拟相结合,系统开展土地利用变化驱动下的生态水文过程——降水入渗和土壤水分的模拟研究。(1)利用大安市1989、2000、2004和2008年四个时段的LANDSAT TM遥感影像,借助ERDAS IMAGINE软件进行影像处理,通过对影像的解译与判读,对土地利用类型进行分类,构建土地利用数据库,利用Arc GIS软件绘制大安市土地利用分布图,其主要土地利用类型为旱地、盐碱地和草地;建立单一动态度模型,滩地减少最为明显,水田增加速度最快;建立转移矩阵分析模型,盐碱地转化旱地的面积最多,草地次之,没有其他土地利用类型转化为盐碱地。结合遥感影像数据和资料整理数据,耕地面积和水域面积都呈现出了先减少后增加的趋势,且二者面积的最大值都出现在近几年,这与“吉林省保障粮食生产的土地开发整治规划”中水利项目的投入与使用有重大关系。(2)基于研究区土地利用变化的规律,有针对性地选择了典型地段,进行表层样品和剖面样品的采集,在室内完成土壤含水量、土壤容重、田间持水量和土壤质地以及颗粒分级等工作,利用实验获得的数据,分析了表层土壤水平方向与剖面的变化规律。研究区土壤主要为砂粒、粉粒和粘粒,其中砂粒含量最高,分布规律为西北多、东南少,而粉粒和粘粒的分布刚好与砂粒相反。表层土样的含水量、田间持水量和容重的分布规律均为西北、西南和中东部多;剖面不同层的土样的含水量、田间持水量和容重随深度变化呈现出基本一致的变化趋势。林地、旱地的三个参数都相对较小,而对应的则是荒草地、盐碱地等其值都相对较高。(3)将实验获取的土壤数据作为基础数据,以Arc GIS软件为平台,选用SWAT模型,结合DEM高程数据、气象数据和土地利用数据,进行降水入渗量的模拟。同时,引用降水入渗系数法对SWAT模型模拟的准确性进行验证,以此讨论不同土地利用类型对降水入渗的影响。研究区单位面积降水入渗量最大的为林地,最小的为难利用地;土地利用-土壤类型组合中草地-黑钙土和草地-草甸土降水入渗系数较大,盐碱地-碱土降水入渗系数较小。运行SWAT模型得到2008年平均降水入渗量的模拟结果为58.75mm,降水入渗总量2.65×108m3,降水入渗系数法计算得到的2008年平均降水入渗量为59.23mm,降水入渗总量为2.67×108m3。两种方法得到的2008年降水入渗总量较2000年的数值相比都呈现出增长的趋势。(4)选取研究区主要作物玉米作为研究对象,在气象数据、作物数据和土壤数据的基础上,结合当地灌溉数据,利用SWAP模型对该区的玉米进行了全生育期的模拟,同时分析了地表以下100cm土柱(根系层)的土壤水分的动态变化过程、水量均衡情况,并利用2008年和2009年的数据进行模型的率定和检验。研究区土壤水的主要来源为大气降水和灌溉入渗水,水分消耗主要为作物蒸腾、土壤蒸发、渗漏、作物截留与模拟土层的储水量变化,在玉米的生育期内,降雨量和灌溉量主要用于作物蒸腾和土壤蒸发。模拟土柱的底部水流通量不大,在施行灌溉或者降水量较大的情况下,土层存在着少量的深层渗漏的现象,但入渗的水量大部分仍储存于土层中,储水量较为稳定。在8~9月作物蒸腾十分强烈,导致土壤水变化较为剧烈,但仍处于不断转化的动态平衡过程。综上所述,本文在研究土地利用变化特征的基础上,结合室内实验,应用SWAT模型和SWAP模型分别进行降水入渗量和土壤水分动态变化的模拟,进而为土地利用变化对降水入渗和对土壤水的影响两个方面的研究提供了重要的数据基础,为近些年来在土地格局上发生较大变化的大安市在生态和水资源管理等方面提供理论依据。
[Abstract]:With the rapid development of social economy and the continuous influence of human activities, the ecological hydrological process has been greatly affected. Land use / land cover change (LUCC) is an important factor affecting the ecological and hydrological environment in the complex activities of human beings, and is also a hot research topic in today's society. As an important part, the response of groundwater and soil water to the change of land use is also very obvious. The precipitation infiltration is an important form of groundwater recharge and has a very important influence on the groundwater. Dagan city is located in the hinterland of the Songnen Plain, which belongs to the fragile ecological area of China. The ecological problems, such as the increasing of the problem and the decline of the groundwater level, are becoming more and more serious. This paper, taking the city of Daan as the research object, combines the 3S technology with the experiment and model simulation, and systematically carries out the ecological hydrological process driven by the change of land use - precipitation infiltration and soil moisture simulation. (1) the use of Daan City in 198920002004 and 2008 four LANDSAT TM remote sensing images of a period of time are processed with the aid of ERDAS IMAGINE software. Through the interpretation and interpretation of the images, the land use types are classified, the land use database is constructed, and the land use distribution map of Daan city is drawn by Arc GIS software. The main types of land use are dry land, saline alkali land and grassland. The dynamic model has the most obvious decrease in the beach land and the fastest increase in the paddy field, and the transfer matrix analysis model is established. The area of the saline alkali land conversion to dry land is the most, the grassland is the next, and no other land use type is converted into saline alkali land. The trend is added, and the maximum value of the area of the two is in the last few years. This has a great relationship with the investment and use of water conservancy projects in the "land development and regulation plan of Jilin province to ensure grain production". (2) based on the law of land use change in the study area, the typical area is selected to carry out the mining of surface samples and section samples. The soil water content, soil bulk density, field water capacity, soil texture and particle classification are completed indoors. The variation of horizontal direction and profile of surface soil is analyzed by the data obtained in the experiment. The main soil in the study area is sand, powder and clay, among which the content of sand is the highest and the distribution law is more in the northwest and less in the southeast. The distribution of the water content, the field water holding capacity and the bulk density of the surface soil samples are all in the northwest, in the southwest and in the Middle East, and the soil moisture content, the field water holding capacity and the bulk density vary with the depth. The three parameters of the woodland and the dryland are all relative. It is smaller, and the corresponding value is relatively high. (3) take the soil data obtained by the experiment as the basic data, take the Arc GIS software as the platform, select the SWAT model, combine the DEM elevation data, the meteorological data and the land use data to simulate the precipitation infiltration quantity. At the same time, the precipitation infiltration coefficient method is used for the SWAT model. The accuracy of the simulation is verified to discuss the effect of different land use types on the infiltration of precipitation. The largest amount of precipitation infiltration in the study area is the forest land, the smallest is difficult to use, and the rainfall infiltration coefficient of the grassland - percolate and meadow soil in the land use - soil type combination is larger, and the saline alkali soil precipitation infiltration system The simulation results of the average precipitation infiltration in 2008 are 58.75mm, the total amount of precipitation infiltration is 2.65 x 108m3, the average precipitation infiltration in 2008 is 59.23mm, the total amount of precipitation infiltration is 2.67 * 108m3. two methods in 2008, and the total precipitation infiltration in 2008 is compared with 2000 value. (4) the main crop Maize in the study area was selected as the research object. On the basis of meteorological data, crop data and soil data, combined with local irrigation data, SWAP model was used to simulate the whole growth period of Maize in this area, and the dynamics of soil moisture in the 100cm soil column (root layer) below the surface was analyzed. The change process, water balance, and the use of 2008 and 2009 data to determine the model rate and test. The main source of soil water in the study area is atmospheric precipitation and irrigation infiltration, water consumption is mainly crop transpiration, soil evaporation, leakage, crop interception and Simulation of soil water storage changes, during the growth period of corn, rainfall And the amount of irrigation is mainly used for crop transpiration and soil evaporation. The flow flux at the bottom of the simulated soil column is small. In the case of irrigation or heavy rainfall, there is a small amount of deep seepage in the soil layer, but most of the water in the soil is still stored in the soil layer, and the water storage is more stable. In the 8~9 month, the crop transpiration was very strong. The change of soil water is more intense, but it is still in the dynamic equilibrium process of continuous transformation. On the basis of the study of the characteristics of the land use change, this paper applies the SWAT model and the SWAP model to simulate the rainfall infiltration and the dynamic changes of soil moisture on the basis of the study of the characteristics of land use change. The study of the two aspects of the influence of soil water provides an important data base and provides a theoretical basis for the great changes in the land pattern in recent years in the management of ecology and water resources.
【学位授予单位】：吉林大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S152.7

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