渭南地区近年植被覆盖动态变化特征分析

Analysis on Dynamic Change Characteristics of Vegetation Cover in Weinan Area in Recent Years

植被覆盖动态变化研究对一个区域的生态变化研究有着重要的意义。基于Landsat 8卫星2013~2020年OLI多光谱数据,生成该研究区域不同时间尺度归一化植被指数(NDVI)专题图,以及不同时间尺度的土地利用专题图。采用趋势分析,相关性分析法研究不同时间尺度、不同土地利用类型的NDVI变化。研究结果表明:(1)2013~2020年间渭南地区平均NDVI值介于0.4与0.7之间。其中2016年相较于2014年平均NDVI值增加了35%,2016年之后NDVI值略有下降,至2019年回升到最高值。2013~2020年渭南地区夏季平均NDVI值变化基本趋于稳定;(2)NDVI值的变化,与气温、降水量在一定区间内呈现相同的趋势;(3)2013年至2019年渭南市植被覆盖整体呈上升趋势。研究表明,随着国家生态文明建设的不断深入,渭南市植被覆盖变化趋于稳定,整体呈上升趋势。

The study of dynamic change of vegetation cover is of great significance to the study of ecological change in a region.Based on the oli multispectral data of Landsat 8 satellite from 2013 to 2020,the normalized vegetation index(NDVI)thematic maps of different time scales and land use thematic maps of different time scales were generated.The results showed that(1)the average NDVI value of Weinan area from 2013 to 2020 is between 0.4 and 0.7.The average NDVI value in 2016 increased by35%compared with that in 2014.After 2016,the NDVI value decreased slightly and recovered to the highest value in 2019.From 2013 to 2020,the average NDVI of Weinan area in summer tends to be stable.(2)The change of NDVI value showed the same trend with temperature and precipitation in a certain range.(3)From 2013 to 2019,the vegetation coverage of Weinan City showed an overall upward trend.This study shows that with the deepening of the construction of national ecological civilization,the change of vegetation coverage in Weinan City tends to be stable,and shows an overall upward trend.