泾惠渠灌区旱灾危机预警研究

Early warning system of drought crisis for Jinghuiqu irrigation district

旱灾是所有自然灾害中影响人口最多,范围最广,驱动因素也最复杂的一种灾害,常威胁区域农业经济发展与社会稳定。而现行的旱灾应对体制多关注气象驱动与旱情监测,对干旱事件发展的过程模拟与危机管理缺乏研究,尤其对人类活动的驱动性影响考虑不足,常因整合性预警体系的缺失,导致旱灾危机诊断和抗旱决策信息不够充分,进而引发农业经济损失。因此,完善旱灾危机预警系统对区域防灾减灾以及社会可持续发展具有重要意义。本文定义了有别于旱情和旱灾的旱灾危机的概念与内涵,考虑了人类活动对旱灾形成过程的影响,并基于旱情评估、水文模拟、水资源调控、危机预警等模型构建了面向灌区的旱灾危机预警系统,以实现对旱灾危机从诊断、预警到决策的全过程支持。系统以泾惠渠灌区为研究区,通过将干旱状态指标与抗旱能力指标相融合,构建了综合旱灾危机预警指标(DCAI),表征灌区未来3个月的危机情势,通过对校验期灌区旱灾危机的滚动预警与决策模拟,发现预警指标与决策建议与官方发布的监测结果较为一致,进一步验证了旱灾危机预警系统与应对机制的科学性与适用性,认为其预期可为灌区干旱管理与危机应对提供决策支持。

Drought disaster is generally considered as a multifactorial-driven natural hazard, affecting the largest population and the widest range, which often threatens agricultural economic development and social stability. The current drought management pays more attention to meteorological change and drought monitoring and plays an important role in defending the disaster. However, it is unfortunate that the researches on process simulation and crisis management of drought event are lack, especially on considering the influence of human activity, and even often lead to the insufficient information for drought decision-making due to the lack of integrated early warning system, causing great agricultural economic loss. Therefore, it is of great significance to improve the early warning system of drought crisis for regional disaster prevention and social sustainable development. This paper defined the concept of drought crisis, describing its connotation and emphasized the influence on drought development of human activity. According to this concept, the index system to evaluate drought crisis was built, and formed the drought crisis early warning system for irrigation districts by coupling with hydrological simulation model, water resources allocation model, crisis warning model and other models. The warning system is to provide a whole-process support for drought crisis management from diagnosis, early warning to decision-making. The drought crisis alarm index ( DCAI ) in this system is constructs by integrating the drought status index and drought resistance index, which is employed to represent drought crisis regime in the next three months. In this paper, the Jinhuiqu irrigation district is taken as a case area. Result of drought crisis early warning during the verification period, show that the simulated alarm information and decision-making advice are consistent with the official version, further verifying the scientific and applicability of the drought crisis early warning system and coping mechanism. It can provide decision support for drought management and crisis response in irrigation districts.