嫩江中下游湿地生态水文功能及其退化机制与对策研究

嫩江中下游湿地是我国自然湿地主要集中分布区之一,是东北松嫩平原生态安全的重要保障。近50年来,在全球气候变化和高强度人类活动的作用下,湿地生态系统严重受损,生态水文功能急剧退化,抵御自然灾害的能力减弱或丧失。本文重点阐述了嫩江中下游湿地的主要生态水文功能,并系统地分析了湿地生态水文功能退化的自然因素与人为因素,认为全球气候变化导致的气温上升和降水量减少、中上游用水量增加与水利工程建设导致流域下游湿地水源补给量锐减、大规模的湿地农田化和过度放牧、农业非点源污染是湿地景观演变和生态水文功能退化的主要机制。根据统筹人与自然和谐的科学发展观,提出了恢复和重建嫩江中下游湿地生态系统的对策和措施,从而保证湿地生态水文功能的正常发挥,保障区域生态环境与社会经济协调、稳定与可持续发展。

Study on the Wetland Ecological and Hydrological Functions and Their Degradation Mechanisms and Countermeasures in the Middle and Lower Reaches of Nenjiang River

The wetlands of the middle and lower reaches of Nenjiang River are one of principally centralized distribution regions of natural wetlands in China,which are important to guarantee the ecological safety of Songnen Plain located in Northeast China.In the last five decades,wetland landscapes have been severely destroyed due to global climate change and human activities,which has resulted in the rapid degradation of ecological and hydrological functions and the lowering or loss of the capacities to resist natural disasters.In this paper,the important ecological and hydrological functions of wetland are illustrated and their degradation mechanisms in the middle and lower reaches of Nenjiang River are analyzed systematically.The temperature rising,precipitation reduction and sharp decline in surface runoff,combined with large-scale reclamation of wetland,overgrazing and non-point source pollution are considered the crucial driving forces for the evolution of wetland landscape and degradation of wetland ecological and hydrological functions.Finally,in terms of the standpoint of scientific development,the countermeasures to restore and reconstruct the wetland landscape and wetland ecological and hydrological functions are proposed,in order to ensure the harmonious,consistent and continuous develompent of eco-environment and socio-economy.