青藏高原生态气候因子的空间格局

基于1966—2005年间青藏高原及其周边113个气象站的观测资料，对研究区最热月均温、最冷月均温、≥10 ℃日数、潜在蒸散、年降水量和干燥度指数的空间格局进行了分析.结果表明：青藏高原最热月均温在7 ℃～20 ℃，由东部周边地区向中部呈逐渐减小趋势;最冷月均温在-18.4 ℃～8 ℃，由南向北逐渐减小;青藏高原≥10 ℃日数由东部周边向中部地区逐渐减小，研究区东南部的≥10 ℃日数最大（150 d以上），中部地区最少（<50 d）;研究区年均降水量由东南部向西北地区呈减少趋势;青藏高原的潜在蒸散（由Thornthwaite模型计算）由东南向西北逐渐减小，大部分地区在330～750 mm;青藏高原干旱地区所占比例较大，主要位于研究区西北部，湿润地区面积小，主要位于东部和东南部.青藏高原的植被分布与其生态气候限制因子有较好的一致性，生态气候因子可较好地刻画植被分布状况.

Spatial patterns of eco-climatic factors on Tibetan Plateau.

Based on the 1966〖KG-*3〗-〖KG-*7〗2005 observation data from 113 meteorological stations on the Tibetan Plateau and its surrounding areas, the spatial patterns of mean temperature of warmest month (TWM), mean temperature of coldest month (TCM), duration of mean daily temperature ≥10 ℃ (DT10), annual precipitation (AP), mean annual potential evapotranspiration (PE), and annual arid index (AI), on the Plateau were analyzed. It was shown that the TWM was 7〖KG-*2〗-〖KG-*7〗20 ℃, which decreased from eastern surrounding area to the central region, while TCM was -184 ℃ to 8 ℃,being decreased from south to north. The DT10 decreased from eastern surrounding area (>150 days) to central region (50 days), and the AP decreased from southeast to northwest. The PE calculated by Thornthwaite model decreased from southeast to northwest, and was 330〖KG-*2〗-〖KG-*7〗750 mm in most parts of the study area. Arid area occupied a larger proportion and mainly located in the northwest of Tibetan Plateau, while humid area was smaller and mainly located in the east and southeast of the Plateau. The vegetation distribution on Tibetan Plateau had good correlations with the test eco-climatic factors, suggesting that these factors could better characterize the vegetation patterns on Tibetan Plateau.