基于遥感的磴口县土地利用/覆盖变化研究 英文标题:A Study of LUCC in Deng Kou Based on Remote Sensing

土地利用/覆盖变化对全球环境变化有着重要指示意义，成为当前国内外研究的热点之一。磴口县位于绿洲-沙地交错带，人类活动历史悠久，是我国土地利用变化最为剧烈的地区之一。本文以研究区21世纪以来三期遥感影像为主要的数据源，根据不同土地利用类型的光谱特征，应用分层提取方法和监督分类，获取了研究区2000、2007、2013年土地利用/覆盖信息。在GIS和ENVI软件的支持下，分析了近14年以来研究区土地利用/覆盖变化的时空特点、土地利用类型的转化过程，重点研究了研究区沙地的变化特征。从自然因素和社会因素两方面对磴口县土地利用/覆盖变化的驱动力进行了分析。论文的主要结论为:(1)利用地物的光谱特征，建立多级分层综合分类方法，设计地物的提取公式和规则，实现了研究区特定土地利用/覆盖类型的分类提取。分类总精度达到了80%以上，Kappa系数达到0.8以上，分类精度较高，分类方法易于理解，分类效率较高，其信息提取方法在相似地区具有一定借鉴意义。(2)磴口县土地利用结构以沙地和耕地为主，沙地面积占研究区土地总面积的近50%，耕地占研究区土地总面积的近27%，林地面积和草地面积占研究区土地总面积的10%，城乡工矿居民用和水域面积占本区总面积的4%。根据比重看，研究区主要是以沙地和耕地为主农牧交错区。(3)2000~2013年，土地利用发生了较大变化。主要表现为林地、耕地面积的大幅度增加和沙地面积的减少。其中林地的面积增长率最高，达55.97%，面积增加156.19km2，耕地面积增加180.14km2，增加率近38.73%。沙地面积减少383.86km2，减少率为81.65%。研究区各土地利用类型转化的主要特点为沙地向耕地以及耕地向林地的转化。2000年到2013年共有近有98.5 km2的耕地转化为林地，205km2的沙地转化为耕地。在空间上，沙地与耕地的互相转化发生在沙漠与绿洲交接地带以及黄河流域周围，耕地、林地互相转化集中在耕地周围。耕地、林地、草地与未利用地的转化主要发生在靠近黄河的灌溉区。沙地和未利用土地转化以研究区西部盐碱区最明显。2000~2013年研究区沙地类型变化显著，流动沙地和半流动沙地逐渐向固定和半固定沙地转化。沙地重心向西南方向移动。21世纪以来研究区呈现“逆沙漠化”态势。(4)磴口县土地利用/覆盖变化受研究区自然因素和社会经济因素共同影响。自然因素中水文要素是研究区土地利用/覆盖变化的主要驱动力之一，对研究区土地利用/覆盖变化影响较大。在社会经济影响因素中，政策因素是研究区土地利用/覆盖变化的决定驱动力。人口的增加，经济发展的迅速发展也带动了研究区土地利用的变化。

Land Use/Cover Change (LUCC), a critical indicator of global environmental change, has emerged as one of the hottest research topics both domestically and internationally. Dengkou County, located in the oasis-desert ecotone with a long history of human activities, is one of the regions with the most dramatic land use changes in China. This study takes three phases of remote sensing images of the study area since the 21st century as the main data source. Based on the spectral characteristics of different land use types, hierarchical extraction and supervised classification were applied to obtain land use/cover information of the study area in 2000, 2007 and 2013. With the support of GIS and ENVI software, this study analyzed the spatio-temporal characteristics of LUCC, the transformation process of land use types, and focused on the change characteristics of sandy land in the study area over the past 14 years. The driving forces of LUCC in Dengkou County were analyzed from two aspects: natural factors and social factors.

The main conclusions of this paper are as follows:
(1) By utilizing the spectral characteristics of ground objects, a multi-level hierarchical comprehensive classification method was established, and extraction formulas and rules for ground objects were designed, realizing the classification and extraction of specific land use/cover types in the study area. The overall classification accuracy reached over 80%, and the Kappa coefficient exceeded 0.8, indicating high classification accuracy. This classification method is easy to understand and has high information extraction efficiency, and its information extraction approach can provide reference for similar regions.
(2) The land use structure of Dengkou County is dominated by sandy land and cultivated land. Sandy land accounts for nearly 50% of the total land area, cultivated land accounts for nearly 27%, forest land and grassland account for 10% of the total area, while urban, rural, industrial and residential land plus water area accounts for 4%. Judging from the land use proportion, the study area is an agro-pastoral ecotone mainly dominated by sandy land and cultivated land.
(3) From 2000 to 2013, significant changes occurred in land use, mainly manifested as the substantial increase in forest land and cultivated land area and the reduction in sandy land area. Specifically, forest land had the highest area growth rate of 55.97%, with an area increase of 156.19 km²; cultivated land area increased by 180.14 km², with a growth rate of nearly 38.73%; while sandy land area decreased by 383.86 km², with a reduction rate of 81.65%. The main transformation patterns of land use types in the study area were the conversion from sandy land to cultivated land and from cultivated land to forest land. From 2000 to 2013, a total of nearly 98.5 km² of cultivated land was converted to forest land, and 205 km² of sandy land was converted to cultivated land. Spatially, the mutual transformation between sandy land and cultivated land occurred in the ecotone between desert and oasis and around the Yellow River basin; the mutual transformation between cultivated land and forest land was concentrated around existing cultivated land; the transformation among cultivated land, forest land, grassland and unused land mainly occurred in the irrigation areas near the Yellow River; the transformation between sandy land and unused land was most prominent in the saline-alkali area in the western part of the study area. The types of sandy land changed significantly from 2000 to 2013: mobile and semi-mobile sandy land gradually transformed into fixed and semi-fixed sandy land. The gravity center of sandy land shifted to the southwest, and the study area has shown a trend of reverse desertification since the 21st century.
(4) LUCC in Dengkou County is jointly affected by natural factors and socio-economic factors. Among natural factors, hydrological elements are one of the main driving forces of LUCC in the study area, exerting a relatively significant impact. Among socio-economic influencing factors, policy factors are the decisive driving force for LUCC in the study area. Population growth and rapid economic development have also promoted changes in land use in the study area.

搜集汇总

背景与挑战

背景概述

该数据集基于遥感技术研究了磴口县2000年至2013年的土地利用/覆盖变化，揭示了沙地和耕地为主的土地利用结构及其动态变化，分类精度高，并分析了自然和社会经济因素对变化的驱动力。