修建防渗渠道对柴达木盆地戈壁区河流生态系统的影响

为摸清修建防渗渠道对戈壁区河流生态系统的影响,以期能为柴达木盆地农业绿洲制定可持续发展的政策提供依据,在社会经济调查的基础上,以大格勒流域为研究对象,通过野外取样和室内化验,对比分析了修建防渗渠道前后的地表河流水质、河岸植被及土壤理化性状。研究结果表明①修建防渗渠道对河流水质具有净化作用,但效果不显著(P>0.05);②修建防渗渠道不利于戈壁区沿河植被繁殖生长,流域内植被平均盖度降低4.5%,生物量减少330.2 kg/hm²,死亡率增加6.5%;河岸土壤质地呈现退化趋势(P<0.05),其中砂粒含量增加8.68%,有机质减少0.53 g/kg。基于以上研究成果,建议在河流出山口处修建生态闸,洪水期引洪灌溉河岸植被;布设生态水利工程,以实现流域生态环境与绿洲社会经济的可持续发展。

Impacts of Anti-seepage Channel Construction on River Ecosystemin Gobi Area of Qaidam Basin

In order to investigate the impacts of anti-seepage channel construction on the river ecosystem in Gobi area and to provide reference for the sustainable development policy of agricultural oasis in Qaidam Basin,we compared the water quality of surface rivers,the riparian vegetation,and the physical and chemical properties of soil before and after the construction of anti-seepage channels in Dagele watershed through field sampling and laboratory analysis based on socio-economic surveys.Results reveal that 1)constructed anti-seepage channels could purify river water quality,but the effect is insignificant(P>0.05);2)anti-seepage channels are not conducive to the reproduction and growth of riparian vegetation in Gobi area,with the average coverage ratio decreased by 4.5％,biomass decreased by 330.2 kg/hm2,and vegetation mortality increased by 6.5％;3)the soil texture displayed a degrading trend(P<0.05),with the sand content increasing by 8.68％and organic substances decreased by 0.53 g/kg.Ecological sluices at the outlet of mountains are recommended for the flood diversion and irrigation in flood season.Ecological water conservancy projects should also be constructed to achieve a sustainable development of eco-environment in the basin.