祁连山草地植被NDVI变化及其对气温降水的旬响应特征  

Variation in Grassland Vegetation NDVI and Its Ten-Day Response to Temperature and Precipitation in the Qilian Mountains

作　　者：戴声佩[1] 张勃[1] 王强[1] 马中华[1] 邹悦[1] 张亚宁[1] 

机构地区：[1]西北师范大学地理与环境科学学院,兰州730070

出　　处：《资源科学》2010年第9期1769-1776,共8页Resources Science

基　　金：国家自然科学基金项目(编号:40961038);中国科学院知识创新工程重要方向项目(编号:KZCX2-YWQ10-4);公益性行业(气象)科研专项(编号:GYHY200806021-07);生态经济学省级重点学科(编号:5001-21);西北师范大学地理与环境科学学院学生学术科研基金项目(编号:2010DLXSKY-01-03)

摘　　要：本文利用SPOTVGT-NDVI数据和旬气温、降水数据,分析了祁连山草地植被NDVI时空变化趋势及其对气温、降水的旬响应特征。结果表明:①1999年-2007年祁连山草地植被NDVI呈缓慢增加趋势。典型草原和平原草地植被年均NDVI和生长季NDVI增加速率高于高寒草甸草地和沙漠草地。祁连山草地植被NDVI增加和减少的面积分别为69776km2和15928km2,植被NDVI增加的区域分布在冷龙岭、拉脊山、大通山、达坂山、青海南山、走廊南山、托来山、托来南山等地区,减少的区域分布在乌鞘岭、大通河、石羊河、黑河、北大河、疏勒河等河流河谷以及青海湖周边地区;②祁连山草地植被NDVI年内月和旬变化曲线均呈单峰型;③祁连山地区气温变化对草地植被NDVI的影响强于降水,气温、降水与草地植被NDVI的最大相关性滞后期都为2旬左右。春季和秋季NDVI对气温和降水响应的滞后期较短,而夏季响应滞后期较长;④气温是影响典型草原生长的主要因素,夏季降水是影响植被生长期内植被生长的重要因子。温度是高寒草甸草地生长的限制因子,而降水量则是沙漠草地、平原草地的生长限制因子。The Qilian Mountains is an important ecological and hydrological zone in Northwestern China,a critical forest-steppe ecosystem and wildlife conservation area,as well as the water sources of inland rivers and the Hexi oasis,such as the Heihe River,Shiyang River,Shule River and Zhangye Oasis,Linze Oasis,Gaotai Oasis,and Shandan Oasis.Examining the vegetation dynamics and environmental changes over this region plays a critical role in studying the environment and climate in China.This paper explores the vegetation dynamics and its relationship with major climatic factors in the Qilian Mountains using SPOT-4 VEGETATION NDVI datasets at 1 km spatial resolution and ten-day temperature and precipitation datasets between 1999 and 2007.Results showed that：1）the grassland vegetation NDVI has been increased in the Qilian Mountains since 1999.The increase rate of yearly average NDVI and growing season NDVI in typical steppe and plain grassland was found to be higher than that in the alpine meadow and desert grassland.The increased and reduced area was estimated to be 69776 km2 and 15 928 km2,respectively.The grassland vegetation NDVI in the Lenglong Ridge,Laji Mt.,Datong Mt.,Daban Mt.,South Qinghai Mt.,Zongwulong Mt.,Tuolai Mt.,and South Tuolai Mt.increased.By contrast,the grassland vegetation NDVI decreased in the Wushao Ridge,Datong River,Shiyang River,Hei River,Beida River,Shule River and the surrounding areas of Qinghai Lake;2）the grassland vegetation NDVI with a single peak curve during the year changed across the Qilian Mountains;it generally reached maximum in July or August.One reason for this phenomenon could be that the precipitation and temperature were both suitable for vegetation growth in July or August,so the NDVI reached maximum.The other reasons could be explained by the grassland in the brown phase from October to February and turning green in March or April.To that end,the vegetation grew slowly and the NDVI tended to be low;3）in the Qilian Mountains,response of grassland vegetation NDVI to the var

关 键 词：NDVI变化 祁连山地区 草地植被 气温降水 响应特征 高寒草甸草地 时空变化趋势 限制因子 

分 类 号：S812.1[农业科学—草业科学] P463.1[农业科学—畜牧学]