基于生态水文学的黄河口湿地生态需水评价

Environmental Flows Evaluation Based on Eco-hydrology in the Yellow River Delta Wetlands

根据生态系统保护的要求,以提高生态系统承载力、保护河口生态系统完整性和稳定性为原则,以促进区域生态系统的良性维持为目标,从生物多样性保护的角度,研究确定了23600hm2的黄河三角洲应补水的湿地恢复和保护规模。在此基础上,采用景观生态学的原理和方法,在湿地植物生理学、生态学、水文学研究基础上及遥感和GIS技术的支持下,研究水分—生态耦合作用机理,建立基于生态水文学的黄河口湿地生态需水及评价模型,并运用预案研究方法和景观生态决策支持系统的规划评价思想,预测和评价了黄河口湿地不同补水方案产生的生态效果,重点研究了丹顶鹤、东方白鹳、黑嘴鸥等指示性物种适宜生境条件与湿地补水后的生态格局变化。评价结果表明,黄河三角洲湿地具备东方白鹳及丹顶鹤等保护性鸟类的繁殖和越冬的潜在生境条件,但其生境质量并不十分理想,通过湿地补水,作为珍稀鸟类重要栖息地芦苇湿地面积从现状的10000hm2增加至22000hm2,生态承载力大幅提高;研究在统筹黄河水资源条件、水资源配置工程措施和湿地生态系统综合保护需求后,推荐提出了黄河三角洲湿地恢复和保护的3.5亿m3黄河补水量及补水时期。

Based on the principles of protecting integrity and stability of ecosystem, and aimed at promoting maintenance of well-conditioned delta ecosystem, as well as improving the carrying capacity of the ecosystem and protecting biodiversity, this paper identified 23,600 hm^2 of wetlands for restoration project which urgently needed to be supplied with freshwater in the Yellow River Delta （YRD）. Whereas, this paper, adopting the principle and methodology of landscape ecology and supported by RS and GIS and wetlands plant physiology, ecology and hydrology, made a study on coupling mechanism between water and ecological process, and therefore, established the eco-hydrology based environmental flow calculation and evaluation model of the YRD. Furthermore, this study uses pre-scheme methodology and planning evaluation concept of landscape ecology decision ＆ evaluation support system to forecast and evaluate ecological effects on the wetlands with different wetlands water discharge scenarios, which focused on the relationship study between suitable habitat conditions for indicator species such as red-crowned crane, Oriental stork, Sander＇s gull and changing ecological pattern after water supplement. The evaluation results show that the wetlands of the YRD have the potential to be the habitat for rare birds such as red-crowned crane, Oriental stork, Sander＇s gull, but the present habitat quality is not good. After discharging water to wetlands, the area of reed wetlands will reach 22,000 hm^2 from 10,000 hm^2 and seablite mudflats will reach 7000 hm^2 from 4500 hm^2, serving as wintering, inhabiting and breeding sites for many rare birds. The habitat quality and carrying capacity will increase notably. In general, after fully taking into account water resources, water allocation engineering measures and integrated requirement of wetlands ecosystem protection, this study proposed recommendation of supplying the wetlands of the YRD with 0.35 billion m^3/a freshwater abstracted from the Yellow River to restore and protect the YRD wetlands ecosystem.