广西中部岩溶区农业干旱成因与治旱对策

CAUSES AND COUNTERMEASURES TO DROUGHT IN KARST AGRICULTURAL AREA IN CENTRAL GUANGXI

桂中岩溶区降水资源和地下水资源丰富,但是,几乎每年都发生旱灾,受旱耕地面积达12.5×104hm2,占全广西受旱面积的55.9%,严重地影响农业经济的发展。综合分析研究表明,桂中岩溶平原区农业生产受旱成灾是气候性、岩溶地质性、工程性因素综合影响的结果。针对致旱原因,提出了①完善和改造水利工程设施,提高水利工程综合利用效率;②充分利用水资源的时空分布规律,实施地表、地下水联合开发;③恢复与重建水源生态环境,调节水循环系统的物流机制,减少水资源流失,增强系统供水功能;④调整土地利用结构,建设良好的农田生态体系,促进资源利用与环境改善的良性循环;⑤调整种植结构,推广节水旱作、土壤改良、农艺节水抗旱技术;⑥调整农业产业结构,形成多元化的农业经济体系;⑦建立完善农村抗早服务体系等综合治旱措施,从抓好水资源的开发、利用、治理、配置、节约、保护和管理七方面入手,提高水资源利用率、完善水土资源优化配置和改善水源生态环境,以增强农业生产的防旱抗旱能力,实现农村经济和社会可持续发展。

In spite of sufficient precipitation and groundwater resources, drought still happens every year in central Guangxi karst area. The farmland hit by droughts amounts to 12. 5×10^4hm^2, accounting for 55.9 percent of that in Guangxi, which badly restrict the development of agro-economy. Synthetic studies show that droughts in agriculture in central Guangxi are caused by climate, karst geology conditions and problematic projects. So ,seven countermeasures are put forward in the paper. （1） Improving irrigation networks and enhancing synthetic using efficiency of the irrigation networks. （2） Combining surface water and groundwater use according to the distribution of water resources. （3） reconstructing the environment of water resource, adjusting the mechanism of water circulation, reducting water loss, and enhancing water supply. （4） Adjusting land use structure and building high-functional eco-agricultural system, as well as prompting the formation of proper circulation in resources utilization and environment amendment. （5） Adjusting plant- ing structure, popularizing techniques of water-saving tillage and soil improvement. （6） Modulating agricultural industrial structure to form multi-elemental agro-economy system. （7） Setting up and perfecting the synthetic anti-drought service system and other measures, which should be started from 7 ways as exploitation, use, harnessment, disposal, saving, protection and management of water resource in order to enhance water use efficiency, improve the optimized disposal of land and water and eco-environment in water-source area, and furthermore, enhance the ability to avoid and resist drought, and finally to reach sustainable devel- opment of rural economy and society.