旱灾成灾综合指数的研究

分析了旱灾成灾的主要影响因素。指出作物的需水状况及环境对水的供应状况是决定旱灾能否发生的关键因素。自然降水的变异、土层水的调贮量、作物不同生育期对缺雨的反应状况及人类活动都会对灾情产生影响。因为不同生育阶段作物的水分敏感度不同，旱灾不是单凭降水距平就可以完全确定，必须根据缺雨程度、缺雨持续时间和缺雨期间作物对水分的敏感度等情况进行综合评价，并给出了全面评价成灾状况的旱灾综合指数。

Study on the Complex Index of the Drought Disaster

The mainly factors of the drought causing disaster are analysed. The results show that the drought disaster occurring mostly depends on the states of the crop water requirement and the environment water supply. The precipitation variability,the water store in soil layers,the crop response on rainfall deficit in the different growing period and hum.an activity influence on the drought disaster. Because the crop sensibility to water in the growing periods are different, the complex evaluation is conducted according to the rainfall deficit, the deficient duration and the crop sensibility to water during the deficient rainfall. The complex index evaluating the drought disaster is also given.