基于Landsat影像2004-2019年哈尔滨市城区植被覆盖度时空变化分析

Spatial and Temporal Change Analysis of Fractional Vegetation Coverage of Harbin City from 2004 to 2019 Based on Landsat Images

城市化带来了经济的发展,同时农村和自然土地的占用会导致环境的恶化和人民生活水平的下降,城市绿地建设在改善城市生态环境和人民居住环境方面发挥着重要作用。本文利用2004年和2019年的Landsat数据研究哈尔滨市城区的植被覆盖度变化,利用二分法分别计算研究区的植被覆盖度;然后两期数据相减获得植被覆盖度变化,提取研究区植被覆盖度增加、不变和减少区域,统计各变化区域的比重并分析其分布和变化原因。结果表明:研究区的植被覆盖度不变区域、减少区域和增加区域各占46.86%、29.32%和23.82%,不变区域最多,增加区域比减少区域略少;植被覆盖度的减少原因主要是城市建筑物的扩张,主要分布在松花江沿岸和老城区周边;而植被覆盖度增加的原因主要是城区各种城区绿地的建设。

Urbanization brings economic development,while the occupation of rural and natural land leads to environmental deterioration and the decline of people’s living standard. Urban green space construction plays an important role in improving the urban ecological environment and people’s living environment. In this paper,Landsat data from 2004 and 2019 were used to study the change of fractional vegetation coverage( FVC) in urban areas of Harbin. The vegetation coverage of the study area was calculated by dichotomy.Then the vegetation coverage changes were obtained by subtraction of the two images,and the areas where the vegetation coverage increased,remained unchanged and decreased in the study area were extracted,and the proportion of each changing area was calculated and the distribution and reasons for the change were analyzed. The results showed that the areas with unchanged FVC,decreased FVC and increased FVC accounted for 46.86%,29.32% and 23.82%,respectively. The decrease of vegetation coverage is mainly caused by the expansion of urban buildings,which are mainly distributed on both sides of Songhua River and around the old city. The increase of vegetation coverage is mainly caused by the construction of various urban green spaces.