黑河下游额济纳绿洲荒漠植被与地下水位埋深的 定量关系

干旱区植被生长与地下水的依存关系是生态水文地质学研究的热点之一。由于降水稀少,中国西北地区植被的生长发育与地下水的关系极为密切,从大尺度上研究地下水变化的生态效应问题对生态环境的保护和恢复具有重要的意义。借助遥感方法,结合地下水观测数据,在区域尺度上定量地研究了我国黑河下游额济纳绿洲荒漠植被发育与地下水埋深的关系。结果表明:适宜植被生长的地下水埋深范围约为2~5 m,当地下水埋深超过5.5 m时,由于植被根系缺水,不能维持冠层正常生长,几乎没有植被发育。

Quantitative relationship between the desert vegetation and groundwater depth in Ejina Oasis, the Heihe River Basin

The relationship between vegetation and groundwater depth in arid areas is one of the most active research topics in ecohydrology.Owing to little precipitation,vegetation is closely related to groundwater depth in the arid inland areas of northwest China.In this study,we investigate the relationship between vegetation and groundwater depth in the Ejina area,located in the northwest arid region of China,by combining remote sensing with in-situ groundwater observations.Our results demonstrate that the groundwater depth suitable for vegetation in this region ranges from 2 to 5 m,depending on species composition.Hardly any vegetation occurs when the groundwater depth is below 5.5 m because the rooting depth of the present species is limited and therefore cannot maintain adequate water supplies to their canopies.