土地利用与景观格局变化对流域侵蚀产沙的影响

发布时间：2018-02-20 19:00

本文关键词： LUCC 水沙产输变异 SWAT模型镇江关流域回归分析景观格局指标　出处：《华北电力大学》2015年硕士论文　论文类型：学位论文

【摘要】：近年来,土地利用/覆被变化(LUCC)及其水文环境效应越来越受到国内外学术界的关注与重视。土壤侵蚀作为土地利用变化引发的主要环境效应之一,将直接影响到区域生态环境变化、林场草场水土保持、水库淤积等环境问题。作为土地利用变化的量化参数,景观格局指标成为研究流域尺度下土壤侵蚀的有效途径。探索流域水沙产输变异规律及其与土地利用、景观格局之间的联系,对优化水土保持、改善人地关系意义重大。岷江北部干流区域具有重要的生态地理位置,水土流失现象已经成为影响当地生态环境的重要问题。本文以岷江镇江关流域为研究对象,基于SWAT模型建立了研究区域分布式水沙模型,对土地利用变化下流域水沙产输变异规律及其与景观格局的关系进行了定量研究,主要研究内容与结论如下：(1)研究了基于SWAT模型的流域分布式水沙模型构建方法,对基于DEM的水系提取与流域划分、水文气象数据库的构建、土壤数据库建立、模拟方法选择、模型参数敏感性设置与分析、模型结果输出与分析验证等建模关键环节进行了阐述,重点探讨了SWAT模型应用于镇江关流域时所应用的技术方法。(2)构建了镇江关流域分布式水沙模型,采用1980-2005年实测水沙资料对模型进行了率定与验证,在1986、1995、2000年三期土地利用格局下,分别对流域地表径流量与土壤侵蚀量进行了验证,结果表明模型能较好地模拟镇江关流域水沙过程。根据多年平均降雨量,采用该模型分别模拟了三期土地利用下各子流域的土壤侵蚀量,并根据汇流顺序计算出各子流域的净侵蚀量与侵蚀模数。(3)利用Fragstats软件工具计算了三期土地利用格局下镇江关各子流域的景观指标,以子流域为样本,通过回归分析方法,寻求景观格局指标变化量与土壤侵蚀变化量间的相关关系。确定了流域产沙相关度较大的指标,建立了不同土地利用格局下模拟的土壤侵蚀量变化与景观指标变化间的相关关系,最终得到镇江关流域土壤侵蚀与景观格局多元回归方程。根据回归方程的实际物理意义与相应景观指标含义,可以为镇江关流域水土保持、水生态环境的改善以及土地利用景观最优化管理等工作提供理论参考。
[Abstract]:In recent years, the land use / Cover Change (LUCC) and the hydrological and environmental effect more and more concern and attention of the academic circles at home and abroad. One of the major environmental effects of soil erosion as the land use change cause, will directly affect the regional ecological environment, water and soil conservation forest grassland, reservoir sedimentation and other environmental problems as a quantitative. The parameters of land use change, landscape pattern index has become an effective way to study on soil erosion in watershed scale. To explore the water sediment transport and variation of land use and landscape pattern optimization of the relationship between soil and water conservation, improve human relations is of great significance. The northern region has an important geographical location of ecology, soil and water loss the phenomenon has become an important issue affecting the local ecological environment. In this paper, Zhenjiang Minjiang River Basin as the research object, based on SWAT model is established in the region Distributed model of water and sediment, the change of basin water sediment transport and its relationship with the variation of land use landscape pattern were studied, the main research contents and conclusions are as follows: (1) research on the methods of constructing SWAT model in distributed hydrological model based on the division of water extraction and watershed based on DEM construction the hydrological and meteorological database, soil database, simulation methods, and set the parameter sensitivity analysis model, model verification and analysis result output modeling key links are described, focusing on the application of technology method SWAT model is applied to Zhenjiang off the river. (2) constructed the Zhenjiang watershed distributed hydrological model. By using the measured data of water and sediment for 1980-2005 years on the model was calibrated and validated in the 198619952000 years of the three land use pattern, respectively on watershed runoff and soil erosion. The verification results show that the model can simulate the closed basin water and sediment process in Zhenjiang. According to the average rainfall, three periods of land use under each sub watershed soil erosion was simulated using the model, and according to the order of convergence to calculate the net erosion and erosion modulus of each sub basin. (3) three land use pattern of Zhenjiang in each sub watershed landscape indexes were calculated by Fragstats software tools, with sub basin as samples, through regression analysis for correlation between landscape pattern index change and the soil erosion amount and quantity. To determine the index of sediment larger correlation, established in different land use related to erosion the relationship between the variation and changes of landscape index between the simulated soil pattern, finally obtained the Zhenjiang basin soil erosion and landscape pattern of multiple regression equation. According to the actual physical meaning of regression equation The meaning of righteousness and corresponding landscape indicators can provide theoretical references for soil and water conservation, improvement of water ecological environment and optimal management of land use and landscape in Zhenjiang watershed.

【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S157;P901

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