农业旱灾系统恢复性评价思路与方法——以河北省邢台市为例
Assessment framework and method of agricultural system resilience to drought——A case study of Xingtai City, Hebei Province
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摘要: 本文回顾了农业旱灾系统恢复性研究进展, 探讨了灌溉农区农业旱灾系统恢复性基本问题, 提出了其恢复性评价思路与框架, 建立了综合指数评价模型, 并以河北省邢台市为例进行了评估。结果表明, 在生长季或年际尺度上, 自然降水偏少对全市旱情有显著影响, 但并不决定最终灾情。旱灾严重程度和系统恢复能力还受到农业资源环境基础、旱灾应对能力及社会经济发展水平等多方面因素影响。持续超采浅层地下水进行灌溉的中部平原地带的县市, 农业旱灾系统恢复指数较高; 缺水、人均耕地资源不足且经济相对落后的西部山地丘陵地区各县市农业旱灾系统恢复指数较低; 在深层地下水超采、地下水漏斗扩展的东部地区, 取水能力强,经济承受力较高的县市, 农业旱灾系统恢复指数较高, 经济落后的县, 恢复指数最低。在生长季或年际尺度上,虽然以水资源持续超采进行灌溉, 全市旱灾总体恢复能力在提高, 但因其忽视了区域水平衡和生态稳定性,所以不具有可持续性。Abstract: Based on review of global research, this paper discussed critical problems of agricultural system resilience to drought in irrigated regions, proposed a framework and advanced a resilience assessment model, using Xingtai City in China’s Hebei Province as a case study. On a time-scale of growing season or year, the results showed that significantly drop in precipitation influenced drought situations in the region. Spatial analysis showed that disaster distribution depended largely on agricultural resources, drought-coping capacity, and social economy level, and not only on precipitation. The central flat areas with over-pumped shallow groundwater (in recent decades) had a higher resilience index. Resilience index was relatively low in the western mountains and hills where water for irrigation was scarce, per capita crop land was insufficient and per capita pure income was low. In the eastern plains, resilience index was quiet mixed. Counties with strong water fetching and financial capacity had much higher resilience capacity and counties with poor economy quiet low. This indicated that economic capacity had a significant influence on agricultural system resilience to drought. On the time-scale of a year, drought resilience that was driven by groundwater over-pumping was not practically sustainable because it neglected physical water balance and ecological stability.