基于GIS的南昌市1995—2015年土地利用时空变化分析

Spatial-Temporal Change of Land Use/Cover in Nanchang from 1995 to 2015 Based on GIS Technology

土地利用/覆被变化(LUCC)是当前区域变化热点问题之一,也是全球变化研究的重点研究问题。由于南昌城市化进程加速,生态环境愈发脆弱,利用南昌市1995年、2005年和2015年土地利用数据,运用数理统计,GIS相关技术,空间分析等方法,针对南昌市近20 a来的土地利用时空变化以及驱动因素进行分析。结果表明:1)1995—2015年南昌市土地利用结构主要以耕地为主,其次是水域、林地、建设用地和其他用地。在此期间建设用地和水域的面积呈上升的趋势,其中建设用地增加的面积最大,20 a内增量为31563.39 hm^2;其他类型面积均呈下降的趋势,其中耕地降幅最大,20 a间降幅达到31054.60 hm^2;2)通过土地利用转移矩阵分析可知,1995—2015年南昌市土地利用变化特征为建设用地扩张和耕地的减少为主,其余用地的变化为辅;在第1阶段主要通过侵蚀耕地来扩张建设用地,第2阶段以建设用地和其他用地的相互转换为主,但第2阶段的建设用地扩张速率明显小于第1阶段;3)从1995—2015年土地利用空间变化分析来看,主城区附近有大量的耕地转移为建设用地,南昌市整体呈“中部变化大四周变化小、耕地转出多其余用地转出少”的态势,研究区内各地类整体变化较为破碎,大面积变化斑块的面积较少;4)运用主成分分析法对南昌市土地利用变化因素进行分析,发现引起南昌市土地利用变化的主要因素有社会经济的发展、人口增长、产业结构的调整以及政策因素。

Land use/cover change(LUCC)is one of the current hot issues of regional change,and is also a key research issue in global change research.As the urbanization process of Nanchang accelerates,the ecological environment becomes more fragile.This study uses the land use data of Nanchang City in 1995,2005 and 2015,and uses mathematical statistics,GIS related technology,spatial analysis and other methods to analyze the spatial and temporal changes of land use in Nanchang City in the past 20 years.The results show that:1)From 1995 to 2015,the land use structure of Nanchang City was mainly cultivated land,followed by water,forest land,construction land and other land.During this period,the area of construction land and waters showed an upward trend,of which construction land increased the most,with an increase of 31563.39 hm^2 in 20 years;other types of areas showed a downward trend,of which the largest decline in cultivated land,the decline in 20 years reached 31054.60 hm^2;2)Through two-stage analysis of the land use transfer matrix,it can be seen that from 1995 to 2015,Nanchang mainly focused on the expansion of construction land.In the first stage,it mainly expanded the construction land by eroding cultivated land,and in the second stage,it was construction land the main conversion is with other land,but the expansion rate of the construction land in the second stage is significantly less than that in the first stage;3)According to the analysis of the spatial change of land use from 1995 to 2015,a large amount of cultivated land has been transferred to construction land near the main urban area,and the overall change in Nanchang is"the central area has large changes and the surrounding area has small changes,the cultivated land has been transferred out and the remaining land has been transferred out"in the study area,the overall changes of various categories in the study area are relatively fragmented,and the area of large-area change patches is less;4)The analysis found that the main factors that caused the land use change in Nanchang City were social and economic development,population growth,industrial structure adjustment,and policy factors.