县域耕地质量评价、更新及其时空格局变化分析研究

发布时间：2018-02-10 03:29

本文关键词： 耕地质量评价 BP神经网络更新时空格局空间自相关　出处：《华中农业大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着我国社会经济的飞速发展,城市扩张和建设用地的增加不可避免的要占用周边稀缺的耕地资源。这些耕地大部分都是生产力较高的优质耕地,使得耕地资源供需矛盾,总产能减少,影响着我国粮食安全。科学的评价耕地质量是落实耕地质量数量双重管理的必要前提,而掌握耕地质量时空格局变化同样是政府科学决策的重点考虑依据之一,具有重要的研究意义。本文以湖北省十堰市郧县为研究对象,从土地肥力、适宜性评价和农业区位等理论研究出发,探讨了耕地质量评价和耕地质量年度更新的模型和方法,分析了耕地质量时空格局变化特征,以期为政府规划决策提供参考依据。主要研究进展和结果总结如下:1、基于BP神经网络方法,探究土壤肥力、自然地貌、基础设置等条件对郧县耕地质量的影响,建立一种科学的耕地质量评价模型,评价出郧县2003和2010年耕地质量状况。将郧县耕地质量评价结果从高向低依次分为五个等级,结果表明:郧县耕地质量整体不高;三等地和四等地占耕地总面积的一半以上,分布在全县大部分地区;一等地和二等地仅集中分布在县域中部和东北部。2、以郧县2010年耕地质量评价结果为基础,分析引起耕地质量年度变更的原因,探究年度更新方法,更新郧县2010-2013年之间变更耕地质量,得到郧县2013年耕地自然质量评价结果。结果表明:郧县年度内因补充开发使得耕地新增427.28公顷,大部分新增耕地为质量较低的五等地;因建设用地占用等原因造成耕地灭失414.91公顷,灭失耕地主要为三等地;因土地整治、农业结构调整等原因使1267.65公顷耕地质量提升,主要由四等地向三等地提升;因土壤污染、耕作不合理等原因造成701.80公顷耕地质量下降,质量下降耕地主要为五等地。3、对郧县2003-2013耕地质量评价结果进行时空格局变化分析。结果表明:郧县从2003年到2013年耕地总量增长15%,耕地质量整体有所提高;一些中低质量的三等地、四等地和五等地分别提升为较高质量的一等地和二等地,一等地和二等地面积总和增加3倍左右。郧县耕地质量在全局和局部均存在空间自相关,表现为耕地质量高的地方和耕地质量低的地方有较显著空间聚集性。
[Abstract]:With the rapid development of social economy in our country, the expansion of cities and the increase of construction land will inevitably occupy the scarce cultivated land resources in the surrounding areas. Most of these cultivated land are high-quality cultivated land with high productivity, which makes the supply and demand of cultivated land resources contradictory. The reduction of total productivity affects the food security in China. Scientific evaluation of cultivated land quality is the necessary prerequisite for carrying out the dual management of cultivated land quality quantity, and mastering the change of temporal and spatial pattern of cultivated land quality is also one of the key considerations in the scientific decision-making of the government. This paper takes Yun County, Shiyan City, Hubei Province as the research object, discusses the models and methods of cultivated land quality evaluation and annual renewal of cultivated land quality from the theoretical research of land fertility, suitability evaluation and agricultural location. The change characteristics of temporal and spatial pattern of cultivated land quality are analyzed in order to provide reference basis for government planning and decision making. The main research progress and results are summarized as follows: 1. Based on BP neural network method, soil fertility and natural landforms are explored. This paper establishes a scientific evaluation model of cultivated land quality, evaluates the cultivated land quality of Yunxian County in 2003 and 2010, and divides the evaluation results of cultivated land quality from high to low into five grades. The results show that the quality of cultivated land in Yunxian County is not high, and the third and fourth grade plots account for more than half of the total cultivated land area and are distributed in most areas of the county. The first and second grade plots are distributed only in the middle and northeast of county. Based on the evaluation results of cultivated land quality in Yunxian County in 2010, the reasons for the annual change of cultivated land quality are analyzed, and the method of annual renewal is explored. To update the change of cultivated land quality between 2010 and 2013 in Yunxian County and obtain the evaluation results of natural quality of cultivated land in Yunxian County in 2013. The results show that the annual increase of cultivated land in Yunxian County is 427.28 hectares due to supplementary development, and most of the new cultivated land is of lower quality. Because of the occupation of construction land, 414.91 hectares of cultivated land have been lost, and the lost farmland is mainly third-class land; the quality of 1,267.65 hectares of cultivated land has been improved due to land renovation and agricultural structure adjustment, mainly from the fourth class to the third class; and because of soil pollution, The quality of 701.80 hectares of cultivated land declined due to unreasonable cultivation. The analysis of temporal and spatial pattern of the evaluation results of cultivated land quality in Yunxian County from 2003 to 2013 showed that the total cultivated land increased by 15% from 2003 to 2013, and the quality of cultivated land was improved as a whole. Some middle and low quality third, fourth and fifth grade land were upgraded to higher quality first and second class land respectively, the total area of first and second class land increased by about three times. There is a spatial autocorrelation between the overall and local cultivated land quality in Yunxian County. The results showed that the high quality of cultivated land and the low quality of cultivated land had significant spatial aggregation.
【学位授予单位】：华中农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：F323.211

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