淮河流域植被NDVI与干旱条件的相关性

(西安科技大学 测绘科学与技术学院,陕西 西安 710054)

归一化植被指数; 干旱; 降水距平百分率; 淮河流域; 相关性

Correlation of vegetation NDVI and drought conditions in Huaihe River Basin
SHI Xiao-liang,SHANG Yu,CHEN Chong,ZHANG Na

(College of Geomatics,Xi'an University of Science and Technology,Xi'an 710054,China)

NDVI; drought; precipitation anomaly percentage; Huaihe River Basin; correlation

备注

淮河流域特殊的地理环境导致干旱灾害频发且持续时间长,严重影响该区域植被生长,而前人大多探讨了该区域气象干旱情况或植被生长状况,对二者之间的关系研究较少,且多采用气象站点降水资料进行干旱分析,不能充分反映降水时空分布的差异性。因此,基于MODIS NDVI遥感影像与TRMM 3B43卫星降水数据,采用降水距平百分率(Pa)作为气象干旱评价指标,分析了2001—2016年淮河流域植被NDVI与降水距平百分率的年际变化特征以及二者的相关性。结果 表明:2001—2016年淮河流域植被NDVI总体呈现稳中有升的趋势,植被NDVI有所改善的区域比例为54.86%,NDVI基本不变的比例为43.25%,仅1.89%的NDVI出现退化。流域16年间以轻旱和中旱为主,较少出现重旱和特旱,干旱程度有所降低。植被NDVI和降水距平百分率呈正相关和负相关的区域分别占流域的61.31%和38.69%,正相关最显著的区域为河南省和安徽省的南部,而河南省东北部、安徽省西北部、山东省西部以及江苏省东部边界呈负相关关系。

The special geographical environment of the Huaihe River Basin has led to frequent droughts with a long duration,which seriously affected the growth of vegetation in the region.There was much talk of themeteorological drought or vegetation growth there with less between.The application of meteorological site precipitation data for drought analysis does not fully reflect the spatial and temporal distribution of precipitation.Therefore,based on MODIS NDVI remote sensing image and TRMM 3B43 satellite precipitation data,this paper analyzes the interannual distinction and correlation between vegetation NDVI and precipitation anomaly percentage of Huaihe River Basin from 2001 to 2016using precipitation anomaly percentage(Pa)as the meteorological drought evaluation index.The result indicates that the NDVI of vegetation in the Huaihe River Basin from 2001 to 2016 shows a stable and a rising trend,with54.86%proportion of improved NDVI in the region,43.25% proportion of unchanged NDVI,and only 1.89%degraded.In the past 16 years,the major drought in the region has been mild and moderate,with less severe or extreme drought,and the degree of drought has reduced.The area with positive correlation and negative correlation of NDVI and precipitation anomaly percentage is 61.31% and 38.69% of the basin,respectively.The area with the most significant positive correlation is the south of Henan and Anhui,while the northeast of Henan province,northwest of Anhui province,western of Shandong province and eastern border of Jiangsu province are negatively correlated.