2017~2019年海北州植被覆盖度时空动态变化分析研究

Analysis on the Spatial and Temporal Dynamics Changes of Vegetation Coverage in Haibei Prefecture from 2017 to 2019

本文旨在对2017年至2019年海北州的植被覆盖度变化进行分析,获得其相关的时空变化规律。基于2017—2019年生长季多时相的GF-1 WFV遥感影像,提取植被覆盖度。为了分析不同覆盖度等级的植被的时空变化,本文将植被覆盖度分为全植被、高植被、中植被、低植被和无植被5个不同等级,并在每个等级内结合DEM数据进一步划分为高山、中山、低山进行分析。研究结果表明:对于植被空间分布特点而言,相对于全植被、高植被、中植被和低植被,无植被的面积占比比较少;在空间分布上,针对不同的海拔高度而言,中山区的植被覆盖度较高,低山区次之,高山区的植被覆盖度最少;从年际变化的角度来看,试验区在2017—2018年和2018—2019年期间,均会出现全植被和高植被相互转化的趋势;在同一年度的生长季,试验区内的植被覆盖度在6-8月呈现上升趋势,在8-9月呈现下降趋势,相对于其他等级,全植被的变化更加符合该趋势。通过本研究,可为掌握海北州植被覆盖度的时空动态变化规律提供支持。

The purpose of this article is to analyze the changes in vegetation coverage in Haibei Prefecture from 2017 to 2019, and obtain the relevant temporal and spatial changes. Based on the multi-temporal GF-1 WFV remote sensing images, the vegetation coverage were extracted. For analyzing the spatial-temporal dynamics pattern, five different levels were grouped by the value of vegetation coverage, which were full vegetation, high vegetation, middle vegetation, low vegetation and non-vegetation, and the area belonged to each level was further sorted by DEM, which were divided as high mountain area, middle mountain area, low mountain area. The results showed that: For the spatial distribution, the proportion of non-vegetation was relatively small compared with another. In the terms of the impact of different altitudes on the spatial distribution of vegetation coverage, middle mountain area performed the best, followed by low mountain area, and high mountain area was worst. From the perspective of inter-annual change, it produced the trend of mutual conversion of full vegetation and high vegetation from 2017 to 2018 and from 2018 to 2019, respectively. From the view of the annual growing season dynamics, it was found that the vegetation coverage in the area showed an upward trend from June to August and a downward trend from August to September. Generally speaking, this research could provide support for grasping the spatial and temporal dynamics of vegetation coverage in Haibei Prefecture.