基于城市地表温度与归一化植被指数对北京市建成区热环境分析

Study on Relationship between Urban Land Surface Temperature and Normalized Differential Vegetation Index

针对研究城市热环境的过程中,利用归一化植被指数(NDVI)进行地表温度(LST)反演,再将LST和NDVI结合说明地物变迁与城市热环境的影响的现状,利用Landsat-8多时相遥感影像、高分辨率影像、公开GIS等多源数据,通过人工交互判读和量化统计分析,实现了2013—2017年北京建成区NDVI变化及其对地表热环境影响分析,再对分析结果进行差值拟合评价。对NDVI阈值分割按照大小为LC1、LC2、LC3、LC4,对LST分为高温区(TH)、常温区(TR)和低温区(TL)。结果表明,2013年至2017年:1)建成区的平均NDVI增加0.03,其中LC1增加1.0%,LC2减少11.6%,LC3区域减少1.7%,LC4区域增加12.3%。2)建成区平均LST增加2.55 K,TH百分比增加0.6%;TR百分比减少1.1%,TL百分比增加0.5%。3)NDVI相对增加,地表温度相对下降以及NDVI相对减少,地表温度相对上升占60%,NDVI相对下降,地表温度相对下降以及NDVI相对增加,地表温度相对上升的占40%。

For research of urban thermal environment in the process,using the normalized difference vegetation index(NDVI)for land surface temperature(LST)inversion,thenLSTandNDVIin combination with terrain changes and the impact of urban thermal environment of the status quo,using Landsat-8 long phase of remote sensing image,high-resolution image,multi-source data,such as public GIS through artificial interactive interpretation and quantitative statistical analysis of 2013-2017 Beijing properNDVIchange and its effect on the surface of the earth thermal environment analysis,differential fitting evaluation on the results of the analysis.The threshold value ofNDVIwas divided into high temperature area(TH),normal temperature area(TR)and low temperature area(TL)for LST according to the values ofLC1,LC2,LC3 andLC4.The results showed that from 2013 to 2017:(1)the averageNDVIin the built-up area increased by 0.03,among whichLC1 increased by 1.0%,LC2 decreased by 11.6%,LC3 decreased by 1.7%,andLC4 increased by 12.3%.(2)the averageLSTincreased by 2.55 K,and theTHpercentage increased by 0.6%.TR decreased by 1.1%and TL increased by 0.5%.(3)with the relative increase ofNDVI,the relative decrease of surface temperature and the relative decrease ofNDVI,the relative rise of surface temperature accounts for 60%,the relative decline ofNDVI,the relative decline of surface temperature and the relative increase ofNDVI,the relative rise of surface temperature accounts for 40%.