贡嘎山极高山区的降水分布特征探讨

从贡嘎山东坡的河川径流观测数据，根据径流形成原理反推高海拔地带的降水变化趋势，发现海拔＞３６００ｍ的地区降水仍在增长．利用径流、蒸发和冰雪消融资料算出极高山区降水的垂直梯度值１９—６６ｍｍ／ｈｍ，其结果与较低位置相邻雨量站观测值（７４ｍｍ／ｈｍ）相吻合．通过降水与气温的垂直梯度变化规律，还可以掌握高山无人带的雨雪变化动态，这对于阐明林线附近的水分特征，研究冰川物质的来源具有重要的参考价值．

EXPLORATION OF PRECIPITATION FEATURES ON EXTRA-HIGH ZONE OF MT. GONGGA

In southwest P8tt of China, most rain gauges are located on positions within 1 0003 000mabove sea level. Seldom records can be found in higher area that leads to lack of information on the precipitation in alpine region. The changing tendence of precipitation in extra-high zone is explored by means of rainfall-runoff generation mechanics. The rainfall increases in region above 3 600 m which cause extra large stream flow. By analyses from runoff.evaporation and snow-ice melting data, the vertical increasing rate of annual precipitation has been derived as 19-66mm/hm in extra-high zone (3 600-6 000m), which can be compared with 74-120mm/hm for lower zone (<3 000m). According to the vertical distribution of temperature and precipitation, the forms of precipitation (rainfall or snowfall) on extra-high region can be determined as well. These characteristics are Anportant in explaining the existing environment of alpine vegetations and material supply of glaciers in at. Gonsga.