毛乌素沙地气候变化及其对植被覆盖的影响

利用1961—2007年毛乌素沙地气温、降水资料,对研究区近50 a来气温和水分资源各分量的时空变化进行了研究,并结合TM影像和中巴资源卫星影像,从气候变化和群落水分收支平衡的角度,对毛乌素沙地近20 a的植被覆盖变化及其原因进行了分析。结果表明:近50 a,沙地增温趋势显著,变化率为0.33℃/10 a。全区域年均温变化趋势的范围为0.16~0.5℃/10 a,且增温的程度存在西北部最强、东南部最弱的趋势。水分资源各分量时空分布极不均匀:东南部降水量P和可利用降水Δw多、陆面蒸散E强,西北部相反。P、E、Δw均呈现出逐年减少的趋势,并且大致经历了3个变化阶段。近20 a毛乌素沙地植被覆盖变化与气候变化密切相关。为适应不断变化的气候需要,在进行沙地治理与生态建设中,必须考虑人工植被建设的可持续性问题。

Climatic Change of Mu Us Sandy Land and Its Influence on Vegetation Coverage

Temperature and each component of water resources in Mu Us Sandy Land were analyzed based on the precipitation and temperature data from 1961 to 2007. Combining of TM images and CBERS images, from climate change and community water balance point of view, the change of vegetation cover and its cause in Mu Us Sandy Land for nearly 20 years are analyzed. The results show that: Over the past 50 years, the trend of warming in Sandy Land is significantly changing with the rate of 0.33 ℃/10 a. The regional variation range of mean annual temperature is 0.16-0.50 ℃/10 a. The warming degree in southeast is stronger than that of in northwest. The various components of water resource in spatial and temporal distribution are uneven: P and Δw are more and E is strong in northwest while which are opposite in southeast. A decreasing trend of P,E and Δw has emerged which roughly experienced three changing stages. For nearly 20 years the changes of vegetation cover and climate in Mu Us Sandy Land are closely linked. In order to adapt to the climate change the construction of artificial vegetation must take into account the issue of sustainability.