西南地区植被对长时间尺度气候特征的响应分析

摘要

以西南五省作为研究对象,使用1999～2012年NDVI数据作为基础数据,结合该时间段的月降水量,运用地理信息系统和遥感技术,分析了西南地区6类主要植被对长时间尺度气候特征的响应.研究结果表明:(1)该区大部分植被的生长与5-9个月尺度的SPI存在很好的相关性,即草原在较长时间尺度上(9～12个月)相关性较好,植被生长受中等时间尺度气候特征的影响.同时该区植被对短期干旱有适应能力.(2)不同类型植被的生长对干旱的响应存在较大差异,即阔叶林耐旱性最好,针叶林次之,草原最小.(3)春季和夏季累计水分亏缺对西南地区植被生长状况具有决定性作用.%Starting from SPOT AVHRR NDVI in Southwest during the period from 1999 to 2012,we get the vegetation growth variability information based on GIS and RS technology,and analyze the six categories of vegetation type response to long time scales of climatic characteristics.The results indicated that,firstly,most of the vegetations show the obvious responses to SPI time-scales of 5-9 months while grassland responds more to SPI time scales longer than 9-12 months and vegetations growth variability in southwest is decided by the meso-scale of Climatic Characteristics;in addition,in this area we found that these vegetations may show certain adaptive capacity in response to short droughts.Secondly,there is great difference in the response of the growth of different types of vegetation to drought:very high for broad-leaved forest,moderate for coniferous forest,and low for grassland.Thirdly,it indicates that vegetation growth in the Southwest is dependent on spring and summer cumulative water deficit.