【摘要】 利用1961—2002青海河湟谷地11个气象台站气温、降水等地面观测资料,对该区气候要素的年代际变化特征及其干旱变化的成因进行了初步分析。结果表明:青海河湟谷地各季节平均气温20世纪90年比60年代偏高了0.4~0.8℃,冬季增温最显著。年平均降水量90年代比60年代偏少17.2mm。地表蒸发量80~90年代比60~70年增多。90年代青海河湟谷地秋季和春季降水量减少,使得秋季和春季干旱发生的频次增加,导致河谷地区的径流量减少。更多还原

【Abstract】 Using the data of temperature,precipitation,ground evaporation from 11 meteorological stations in the valley of the Yellow River and the Huangshui River within Qinghai Province(shortened for Hehuang valley) from 1961 to 2002,we analyzed the characters of meteorological element change and aridity variety.The result is as follows: The season average temperature of Hehuang valley in 1990’s was 0.3~0.5℃ higher than that in 1960’s and 1980’s;Temperature increase was obviously in winter.The annual average precipitation in 1990’s was 17.2 mm less than that in 1960’s.The surface evaporation increase in 1980’s to 1990’s was more than that in 1960’s to 1970’s.The decrease of precipitation in spring and autumn since 1990 made the drought frequency increase in autumn and spring and the valley runoff reduce.更多还原