西藏那曲流域典型测站气候特征分析

以西藏那曲流域的安多站和那曲站两个气象站点逐日气象数据为基础,分别采用Mann-Kendall检验、最大熵谱分析、滑动t检验、Yamamoto检验等方法对两站点的降水量、无雨日、年平均气温以及潜在蒸散量的趋势性、周期性、突变性进行检验,并对降水的年内分配以及不同强度的降水变化趋势进行分析。结果表明:安多站和那曲站年降水量呈显著上升趋势,无雨日显著下降;降水以夏季降水为主,主要分布在6~9月,且以小雨等级为主,中雨次之;各等级降水的年降水量和频次均呈上升趋势;年平均气温、年最低最高气温均呈上升趋势,且年最低气温上升趋势较年最高气温显著,两站年最大温差呈下降趋势;潜在蒸散量的变化趋势与年平均气温的趋势相似。

Analysis on climate characteristics of typical meteorological stations in Naqu Basin of Tibet Region

On the basis of the daily meteorological data of Anduo Station and Naqu Station, the long-term trend of precipitati-on, rainless days, annual average temperature and potential evaporation were analyzed by the Mann-Kendall test, the periodical characteristics were analyzed by maximum entropy spectrum analysis, and the mutation points were detected by MTT test and Yamamoto test. Meanwhile, the paper studied the annual distribution of precipitation and the variation trend of different precipita-tion grade as well. The results showed that there was a significant increase of precipitation in Naqu Basin. The rainless days de-creased remarkably. The precipitation in summer contributed the most, mainly in June to September, which was light rain most-ly, followed by moderate rain. The frequency and amount of different precipitation grade showed an increase. The annual average temperature, maximum temperature and minimum temperature all increased, and the minimum temperature increased more than the maximum temperature. The maximum temperature difference of the two stations decreased. The trend of potential evaporation was similar to that of the average temperature.