中国西南山区蒸散发能力的季节和空间变化(英文)  

Seasonal and Spatial Variation of Evapotranspiration in the Mountains of Southwest China

作　　者：AxelThomas 

机构地区：[1]德国Johannes Gutenberg大学地理学院,梅因兹d55099

出　　处：《山地学报》2002年第4期385-393,共9页Mountain Research

基　　金：国家科技部基础研究快速反应项目 ( 2 0 0 1CCB0 0 6 0 0 );国家重点自然科学基金 ( 39930 130 )资助

摘　　要：从全球范围来看 ,中国西南山区位于热带与亚热带、印度洋季风与中国季风的过渡带 ,属于季风气候。5～ 9月的降水占全年平均降水量的 70 % ,整个山区随海拔高度的变化形成了很多气候带 ,与中国东部相比 ,中国西南山区旱季 (冬季 )温暖 ,光照充足 ,天空晴朗。根据中国西南山区 36个 (主要是云南的 )气象站观测资料 ,利用彭曼修正式估算了中国西南山区蒸散发能力 (PET)。观测资料统计显示这些气象站位于同一气候区的不同类型区域 ,本文中估算了不同类型区域的月平均PET的递减率。各种气候类型区域的季节变化反映了季风影响的程度 ,PET的年内变化可划分为季风前期、季风期和季风后期。PET的区域月递减率在 1mm/ 10mm～ - 5mm/ 10 0mm间变动 ,较低的云雾或云层等局部气候将太阳辐射控制在低水平 ,影响PET的递减率的正、负变化 ,由太阳辐射和风速主导大部分区域PET的最大值出现在季风来临前的 2～ 5月份。在 6～ 9月的季风期 ,中国西南山区受西南季风控制 ,整个区域气候变化比较一致 ,PET的值较小 。Estimations of potential evapotranspiration (PET) were calculated according to a modified Penman formula for 36 meteorological observatories in the mountains of Southwest China, particularly in Yunnan Province. Based on these data stations were grouped in climatically homogenous regions (climate provinces) and the mean monthly PET lapse rate for each climate province was calculated. The seasonal distribution of climate provinces reflects the varying degree of influence of the monsoonal air masses. The intraannual variation of PET can be divided into three seasons (premonsoon, monsoon and postmonsoon). Regional monthly lapse rates vary mainly between -1 mm/100 m and -5 mm/100 m. Positive lapse rates and inversions are assumed to result from local phenomena like ground fog or cloud layers inhibiting solar radiation at lower levels. The highest PET values and the largest spatial range of PET values occur during the premonsoon (February-May), due to large regional differences in solar radiation and wind speed. During the monsoon season (June-September) all parts of the region are under influence of the Southwest Monsoon leading to a homogenous climatic environment, low PET values and small spatial variations of PET.

关 键 词：空间变化 西南山区 蒸散发能力 季风变化 降水量 气候变化 PET 

分 类 号：P426.2[天文地球—大气科学及气象学] P467