江汉平原湿地水系统综合评价与水资源管理探讨

江汉平原分布着由河流湖泊-沼泽-沼泽型水稻土-潜育型水稻土组成的湿地系统。江汉平原湿地在蓄水滞洪、调节气候、水质净化、维持生物多样性和改善生态环境方面有着十分重要的作用。在探讨江汉平原湿地水系统结构和功能的基础上,提出了合理利用湿地水资源和实施科学水管理的途径,首先要对水资源和水环境进行积极的保护;其次积极实施退田还湖,增强江汉平原湿地的调蓄洪水能力,减轻洪涝灾害损失;其三是建立江汉平原水环境安全调控体系;最后将江汉平原湿地水系统管理纳入整个长江中游及长江流域的统一管理与规划之中,进行总体协调与管理。

Comprehensive Evaluation on Wetland Water System and Water Resources Management in the Jianghan Plain

Water is the key factor to form the wetland ecosystem and also the most sensitive component in the wetland ecosystem and it plays an important role in the process of wetland.Wetland is an important ecosystem in the Jianghan Plain, in which water factor affects its structure and function.The Jianghan Plain is the typical region of subtropical wetland ecosystems of China, where there are many lakes and waterways, and the micro-physiognomy is very complex.The alluvial plain is a honeycomb of waterways bordered by natural levees, and the depressional areas encompassed by these waterways are dish-shaped in cross-section, distributing the wetland systems composed of river, lake, marsh, gleyed paddy soils and swamp paddy soils.And the hydrology relationship of the Yangtze River and lakes and rivers is complex and the water system includes water inputting and outputting system of wetland besides the wetland water system.The water resources are abundant in the Jianghan Plain, but precipitation is not even in spatial-temperal distribution and traveler-water volume is instability, which often the collection of water that cause flood and waterlog or the lack of water that cause drought.Wetlands in the Jianghan Plain play an important role in floodwater storage, water quality improvement, climate changes, biological diversity protection and eco-environment improvement.As a storage space for surface water, lakes reduce the risks from flood and waterlog.In generally, Jianghan lake group can accommodate more than 150?10⁸m³ water volume in the year abundant in rain.Honghu Lake is a main lake of storage water in the Jianghan Plain, and acts as the function storing floodwater and irrigating cropland in the middle-low Four Lakes district in the Jianghan Plain.According to some simulation results, the largest storage water volume of Honghu Lake is about 21?10⁸m³.As having a strong self-decontamination capacity, most lakes in the Jianghan Plain are moderate eutrophication.Based on probing into the structure and function of wetland water system in the Jianghan Plain, the approaches and strategies about water resources' reasonably utility and scientific water management are made.Firstly, water resources and environment should be protected actively.Secondly, lakes should be restored from impoldering in order to enhance the storage floodwater capacity of wetland in Jianghan Plain, and to reduce the loss resulted by flood and waterlog.The third, water environment security system should be set up.At last, wetland water management system in the Jianghan Plain should be included in the management and plan of the middle reaches or even the whole of Yangtze River drainage basin.