青海东部旱区自然降水特征及旱害发生关系

Natural Rainfall Features and Its Relation with Drought Disaster in Eastern Dry Area of Qinghai Province

通过对长期自然降水资料的统计分析，结合田间定位试验和微区试验，对土壤水分平衡关系分析的基础上，提出评估旱害的4项指标：贫水指数、凋萎指数、降水指数和干旱指数，并依据干旱指数对浅山地区1961～1999年的粮食生产进行了年型分类，其结果是：39年间共发生特大旱年1年、大旱年3年、中旱年19年、轻旱年11年、平水年5年，发生机率分别为2．6％、7．69％、48．72％、28．21％、12．82％。同时认为青海东部地区旱田作物需水和耗水参数矛盾突出，干旱是年年发生，唯轻重之别，具有明显的不可预测性、多变性和不可控性。抵御干旱的有效措施是实施农田外部人为亏缺补水。

According to the statistical analysis of long-term natural rainfall data from 1961 to 1999, combining field location and micro-area experiment, the four indexes for drought disaster evaluation were put forward based on the analysis of rail water content balance, namely water deficiency index, withering index, rainfall index, and drought index. Using the drought index, the year type for crop production in Qianshan area of Qinghai province during 1961 - 1999 is classified. The results showed that the frequency of extremely heavy drought, heavy drought, middling drought, light drought and rainy year was 1 a, 3 a, 19 a, 11 a and 5 a respectively, and the corresponding probability was 2.6%, 7.69%, 48. 72%, 26. 21% and 12.82%. In the dry-farming region of eastern Qinghai, there is an extrusive inconsistency between crop requirement and water consumption, and the occurrence rate of drought disasters is very high, which is changeful and is difficult to forecast and control. The effective measure for drought resisting is outer water complementarily.