黑河上中游流域植被时空演变规律及其对水热条件的响应特征分析

基于黑河上中游流域1999—2010年SPOT NDVI旬数据及气温、降水旬数据,采用趋势分析和时滞互相关法,对研究区内植被的时空变化规律及其对水热条件的响应特征进行了分析.结果表明:1)1999—2010年,黑河流域上游植被覆盖状况优于中游,中游除张掖市及酒泉市存在人工植被外,其他区域基本不存在人工植被;2)在1999—2010年间黑河上游流域大部分地区的植被均表现出明显退化趋势,中游流域的植被整体表现为轻度退化;3)黑河上中游流域的植被受气温的影响大于降水,而对降水的响应更为迅速.不同类型的植被对气温、降水的响应速度不一.

Spatiotemporal variation of vegetation in response to changes in temperature and precipitation in upper and middle reaches of the Heihe River basin: a SPOT NDVI dataset study

Multi-source remote sensing products for upper and middle reaches of the Heihe River basin from 19992010 were used to conduct time-lag correlation analysis and trend analysis among ten-day NDVI and ten-day mean temperature,ten-day precipitation for each grid,to quantitatively evaluate responses of different types of vegetation to climatic factors.It was found that from 19992010 condition of vegetation coverage in the upper reaches was better than in the middle reaches,where vegetation coverage was rare.The only vegetation coverage in the middle reaches was artificial vegetation in Zhangye City and Jiuquan City.From 19992010,vegetation in the upper reaches suffered significant degradation while vegetation in the middle reaches degraded slightly in general.Precipitation exerted less effect than temperature on vegetation in the upper and middle reaches, while vegetation responded to variation in precipitation more rapidly than temperature.Time-lag of different vegetation to changes in temperature and precipitation varied greatly.