基于洪水问题的洞庭湖湿地区域划分

为了充分发挥三峡水库对洞庭湖防洪的有利作用,缓解其对湖区湿地水文条件的影响,采用水文模型对城陵矶河段的洪水进行情景模拟,并分析了3口洪道的分流现状以及三峡水库运用后荆江防洪的泄流要求.结果表明,进一步提高洞庭湖的蓄洪功能、保护3口洪道的分流能力,仍是实现长江中游防洪安全的必要条件.由此,结合湖区城镇、产业分布与自然地理条件,按"人类活动集中区—扩大蓄洪区—蓄洪区—自然湿地"的梯级层次提出了划分洞庭湖湿地区域的框架.

Wetland zoning in Dongting Lake based on flood conditions

In order to use the Three Gorges Reservoir for the flood control of Dongting Lake and to mitigate its influence on wetlands in the Dongting Lake area, a hydrological model was employed to simulate the flood routing along the Chenglingji River reach. The flood diversion status using three different directions of flood and the discharge requirements of the Jingjiang River after the operation of the Three Gorges Reservoir was also analyzed. The results indicate that improvement of the flood storage capacity in Dongting Lake and protection of the diversion capacity of the three floodways are necessary conditions for flood control safety of the middle reaches of the Yangtze River. Therefore, based on the distribution of towns and industries as well the geographical conditions of the Dongting Lake area, a framework for the wetland zoning of the Dongting Lake area, in step-levels of a central zone with human activities, an expanded flood detention area, a flood detention area and a natural wetland, is put forward.