黑河下游生态调水对水资源时空变化的影响分析

Impact of Ecological Water Diversion on Temporal and Spatial Change of Water Resources in Heihe Downstream

分析了黑河流域地表水、地下水资源在调水前后的时空分布变化,评价了黑河生态调水引起水资源的时空变化规律。黑河在调水前进入下游的水量明显受中游用水影响,20世纪90年代后,进入黑河下游地区的水量逐年减少,导致地下水位下降,出现草场大面积沙化和沙漠化、林地面积减少等生态环境问题。自2000年开始至2003年,按照分步实施、逐步到位的原则,国家对黑河水资源实行统一管理和调度,实现国务院批准的分水方案,自2004年开始转入正常调度,下游来水量比调水前有明显增加,2000～2004年、2005～2008年正义峡断面增加下泄量分别为1.62×108m3、2.35×108m3,哨马营断面来水增加1.34×108m3、1.18×108m3,狼心山断面来水增加1.64×108m3、1.41×108m3。调水后黑河下游区域地下水位逐年回升,整个额济纳绿洲地下水位回升了0.56m,东西河上游、赛汉桃来、吉日格朗图区域地下水位分别回升了0.26m、0.05m、0.78m。使东居延海得到恢复,最大水面面积达35.7km2,西居延海得到一定的水量补给,环湖地区生态环境逐步得到恢复。

We analyzed the temporal and spatial change of surface water and groundwater before and after water diversion in the Heihe River Basin,and evaluated the rule of temporal and spatial change of water resources resulted from ecological water diversion in the Heihe River.It was clearly affected by water use in the midstream before water diversion in Heihe river.After 1990s,the water flow into the Heihe downstream reduced year after year,which resulted in groundwater stage fall,grassland desertification and forest area reduction.From 2000 to 2003,water diversion program water implemented,and runoff quantity in downstream increased.In the period of 2000-2004 and 2005-2008,the increased discharge is 0.162 billion m3 and 0.235 billion m3 at the Zhengyixia section,0.134 billion m3and 0.118 billion m3 at the Shaomaying section,0.164 billion and 0.141 billion at the Langxinshan section.After water diversion,groundwater stage increased by 0.56m in the Ejina oasis,and respectively increased by 0.26m in the Dongxihe upstream,0.05m in Saihantaolai region,0.78m in Jirilanggetu region.The Dongjuyanhai Lake has been restored,with the maximum water area reaching 35.7km2.The Xijuyanhai Lake has been supplied of water,the ecological environment around the lake recovered gradually.