辽宁省多尺度干旱演变及植被响应分析

Analysis of Multi-scale Drought Evolution and Vegetation Resp onse in Liaoning Province

探讨干旱与植被间的关系对干旱影响评估和促进生态建设尤为重要。基于辽宁省2000~2018年MODIS-NDVI及逐日气象数据,运用S_(SPEI)指数、相关及滞后分析等方法分析了19年间辽宁省植被与干旱变化的相关性和滞后效应。结果表明,2000~2018年辽宁省S_(SPEI)指数在不同时间尺度均呈上升趋势,气候经历由干旱变为湿润的过程,且显示的干旱情况与辽宁省历史上干旱年份相符,说明S_(SPEI)指数在辽宁省干旱监测中有较好的适用性;辽宁省总体植被覆盖良好,呈辽东优于辽西,辽西优于辽中的空间分布特征;辽宁省N NDVI与S_(SPEI)指数相关性夏季最强(0.46),秋季次之,春季相对较弱;生长季内,以沈阳、鞍山站为中心的区域相关系数介于-0.43~-0.81之间,呈显著负相关,辽西的朝阳及辽东山区一带则以显著正相关为主。辽宁省54.56%的面积植被对S_(SPEI)指数滞后达3个月,仅大连北部及宽甸植被生长对干旱敏感,无滞后。研究结果可为气候与植被互馈关系的研究和生态环境建设提供一定参考。

It is very important to explore the reiationsnip between drougnt and vegetation for promoting ecological construction and drought evaluation.Based on the MODIS-NNDVI and daily meteorological data of Liaoning Province during 2000-2018,this paper analyzed the correlation and lag effect of vegetation and drought change in Liaoning Province over 19 years using S_(SPEI) indices,correlation and lag analysis.The results show that the S_(SPEI) index of Liaoning Province from 2000 to 2018 showed an upward trend at different time scales.The climate experienced a process of changing from drought to humid,and the drought conditions displayed were consistent with the drought years in Liaoning Province’s history,indicating that the S_(SPEI) index has good applicability of drought monitoring;Liaoning Province has good overall vegetation coverage,showing the spatial distribution characteristics of eastern Liaoning better than western Liaoning,and western Liaoning better than central Liaoning;It has the strongest correlation between NNDVI and S_(SPEI),index in summer(0.46),followed by autumn and relatively weaker in spring;During the growing season,the regional correlation coefficients centered on Shenyang and Anshan stations ranged between-0.43 and-0.81,showing a significant negative correlation,while in Chaoyang and Liaodong mountainous areas in western Liaoning mainly with significant positive correlation.The vegetation of 54.56%of the area in Liaoning Province lags behind the S_(SPEI) index for 3 months.Only the vegetation growth in northern Dalian and Kuandian is sensitive to drought,and there is no lag.The research results can provide a certain reference for the study on the mutual feedback of climate and vegetation and the construction of ecological environment.