气候变化影响下华北平原地下水可持续利用研究

Simulating Dynamics of Groundwater in North China Plain Under Uncertain Climate Change

【目的】研究气候变化对华北平原地下水可持续利用的影响。【方法】在校准的MIKE SHE模型基础上考虑A1B二氧化碳排放情景下代表湿润、正常和干旱气候条件的3种大气环流模型,设定3种气候变化情景进行模拟。【结果】①地下水水位、地下水补给、含水层储量的变化均与气候的干湿程度正相关。相对于保持现状情景,湿润和正常气候情景下地下水水位分别回升0.156~0.295 m/a和0.007~0.090 m/a,而在干旱气候情景下则下降0.106~0.345 m/a;②模拟期末,相对于保持现状情景,湿润和正常气候情景下含水层储量恢复率分别为6.86 km^3/a和0.84 km^3/a,而干旱气候情景下则下降6.58 km^3/a;③湿润和正常气候情景下地下水补给量增幅分别为53.1%和8.5%,而干旱气候情景下地下水补给量降幅为69.2%。【结论】地下水可持续利用是华北平原社会发展中的关键问题,与此相关的措施包括减少蒸散发、城镇化、南水北调工程、节水灌溉技术等。只有社会各方面的综合作用,才能从根源上保障华北平原地下水的可持续利用。

【Objective】Global climate change could result in frequent occurrence of extreme weathers,exerting extra pressure on already dwindling groundwater resource in most arid and semi-arid regions in the world.In this paper we analyze how groundwater in north China Plain(NCP)would change under an uncertain climate change.【Method】The analysis was model-based.We considered three scenarios representing wet,normal and dry climatic conditions as predicted from the A1B carbon dioxide emission.The dynamics of both surface and subsurface water was simulated using the MIKE SHE model.【Result】Change in groundwater level,groundwater recharge and aquifer storage were all positively correlated to the degree of dry and wet weather.Compared with the status quo scenario,the groundwater level in the wet and normal scenarios will rise at a rate of 0.156~0.295 m/a and 0.007~0.090 m/a,respectively,while fall at a rate of 0.106~0.345 m/a in the dry scenario.Compared with the status quo scenario,the aquifer storage in the wet and normal scenarios will recover at 6.86 km^3/a and 0.84 km^3/a respectively,but decline at 6.58 km^3/a in the dry scenario.Groundwater recharge in the wet and normal scenarios will increase by 53.1%and 8.5%respectively,whereas reduce by 69.2%in the dry scenario.【Conclusion】Dwindling groundwater resource is a bottleneck in social development of the NCP,and to improve sustainability of the groundwater use,available mitigations include reducing evapotranspiration,increasing urbanization and developing water-saving irrigation technologies,although diverting surface water from south China also helps.Achieving this goal needs collaborative efforts from the whole society.