充足的生态用水是保证湿地生态系统稳定的主要因素,生态需水计算研究也是对湿地进行补水的前提和依据.结合湿地水的消耗主要是蒸发和渗漏以及工农业用水,提出在不考虑周边地区城市生活及工农业用水的情况下,只需计算湿地蒸散发量和渗透量,就能从一定程度上解决补水量下限的问题.通过相关方法计算出扎龙湿地每年平均适宜生态需水量约为15.4亿m^3,其中蒸散发量约为12.0亿m^3,渗漏量为3.4亿m^3,考虑到区域内天然降水量为6.6亿m^3,得出每年需向扎龙湿地补水至少8.8亿m^3才能维持湿地需水量,同时提出有效解决降水量年内分配的不均匀性问题,雨量大的季节,可考虑少补或不补水;对阻挡水流进入湿地的不合理水利工程,根据实际情况进行拆除;适当减少区内工农业用水,防止用水浪费现象发生;在上游支流修建系列水利工程,拦蓄汛期洪水,在枯水期开闸向扎龙干流补水,实现洪水资源化;采取扎龙湿地水资源敞开式向封闭式管理的转变,以工程手段促进扎龙湿地水源的优化配置等一系列湿地补水措施.
Zhalong wetland, the most integrated, original and capacious wetland ecosystem in North China, is so badly short of water resource that it must be replenished by people to maintain the stability of wetland eco- system. By refering to a lot of overseas and domestic study on ecological water requirement, this paper provide the minimum eco-environmental water requirement of Zhalong wetland according to the calculating results of the transpiration and infiltration in this area and without regard to the municiple, industry and agriculture water requirement. The result showed that the minimum eco- environmental water requirement of Zhalong wetland is 15.4 × 10^8 m^3, including 12.0 × 10^8 m^3 for transpiration and 3.4× 10^8 m^3 fo infiltration. Campareing with 6.6 × 10^8 m^3 precipitation in this region, 8.8 × 10^8 m^3 water must be supplied to the wetland to satisfy its eco- environmental water requirement. In the same time, considering the eco-envi- ronmental status of Zhalong wetland, we discussed the hard issue of water resource faced by the wetland, and brought out some measures to resolve the wetland water supply difficulty.