变化环境下昭通市干旱演变规律分析

Drought Evolution Analysis of Zhaotong City in Changing Environments

摘要: 由于受到气候变化和人类活动的影响，干旱灾害表现出频次增高、持续时间延长和灾害损失加重等非一致性特点。本文基于非一致性水文频率计算原理，提出基于跳跃分析的干旱频率计算方法，并分析变化环境下的干旱演变规律。以云南省昭通市为例，其干旱演变规律表明：昭通现状条件与过去条件相比，干旱发生的等级、频率均发生了显著的变化：特旱在过去条件下发生的概率为0.5%，而现状条件下发生的概率为5%；现状条件下重旱发生的概率是过去条件下的7倍左右。结果表明昭通市的气候向着不利于水资源开发利用和农作物生长的情形发展，也使得昭通市未来的抗旱形势变得更加严峻。

Abstract: Under the influence of climate changes and human activities, drought disaster emerged the incon-sistent features such as rate of recurrence higher, duration longer, disaster losses increased and so on. Based on the inconsistent hydrological frequency calculation principle, put forward the drought frequency calcula-tion based on jump analysis to analyze drought variation under changing environment. The example about Zhaotong Yunnan Province was attached, and the results show that: compared with the past conditions, the level and the frequency of drought occurs a significant change. The probability of occurrence of extraordi-nary drought is 0.5% in the past; but it’s 5% now. The probability of occurrence of heavy drought now is seven times than it’s in past. This indicates that the climate in the Zhaotong City is developing toward the di-rection which is not conducive to the crop growth and the development and utilization of water resources. It will also increase the drought threat in Zhaotong City in the future.