黑河调水对下游生态环境恢复效果的卫星遥感监测分析

Remote Sensing Monitoring and Analysis on Effect of Environmental Recovery in Lower Reaches of Heihe River due to Re-distributing Runoff

利用2002年7月至2003年9月EOS/MODIS资料,计算了黑河尾闾湖———东居延海重新出现后水域面积并分析其变化特征;通过对2002和2003年6～8月黑河下游额济纳旗和古日乃绿洲植被指数的对比分析,了解黑河调水对下游植被恢复的效果。结果表明:东居延海重新出现后仍为季节性湖泊,其面积2002年初冬最大,2003年春季迅速减小并于6月6日干涸。随着中游地区再次向下游调水,2003年8月中旬东居延海再次出现,干涸时间为70d,较前些年大大缩短。东居延海再现后对位于河道周围的额济纳旗绿洲植被恢复效果比较明显,对远离河道的古日乃绿洲植被生长影响不显著。

The water area change of East Juyanhai lake—the terminal lake of Hehei River was estimated by using EOS/MODIS data from July, 2002 to September, 2003. The effect on vegetation recovery of re-distributing Heihe River water was analyzed by contrasting the vegetation index in Ejin Banner oasis and Gurinai oasis from July to September in 2002 and 2003.The results show that the East Juyanhai lake is still a seasonal lake after it being re-inflowed in 2002; its area was the largest in the early of winter in 2002, then reduced rapidly in spring and dried up on June 2003. The lake water area reappeared again in the middle of August 2003. This year the dry period are 70 days and it was shorter than the past. The re-inflow to the East Juyanhai lake has obvious effect on the vegetation recovery of Ejin Banner oasis which is near the Heihe River and has unobvious effect on the vegetation recovery of Gurinai oasis which is farer away from the Heihe River.