黑河地表-地下水交互作用对水量调度的影响

Impacts of surface-groundwater interaction on water regulation in middle reaches of Heihe river basin

地表-地下水交互作用关系对于水资源调度管理具有重要影响,深入理解这一关系是进行科学调度的基础。本文基于MODFLOW建立了黑河中游地区的地表-地下水联合模拟模型,通过1995—2000年间的实测资料对模型进行了参数率定和模型验证,并模拟了2001—2006年黑河水量调度实际情况。结果表明,黑河流域地表-地下水之间的交互作用是影响调度效果的重要因素,丰水年河水补给地下水导致河道下泄比例偏低,枯水年地下水补给河水导致河道下泄比例偏高。对比丰水的2003年和枯水的2001年,地下水向河道的净补给量减少了将近2亿m3,因此在丰水年即使压缩中游用水也无法完成正义峡分水指标,导致了分水方案执行过程“越丰水越难完成任务”的现象,建议通过调整分水方案或者增加调蓄工程来解决这一问题。

Surface-groundwater interaction relationship has significant impacts on water resources dispatch and management.A deep understanding of this relationship between surface and groundwater is the basis of scientific system dispatch.This paper develops a surface-groundwater joint simulation model in the middle reaches of the Heihe river by using MODFLOW to simulate the surface-groundwater interaction of this area.The developed model is calibrated and verified by using the observed data during 1995-2000,which shows a good model performance.By applying the model to the simulation of water regulation practice of 2001-2006,it is shown that the interaction between surface water and groundwater is an important factor affecting the regulation.The proportion of river channel discharge is low rate in wet years but high rate in dry years due to water exchange relationship of surface-groundwater.By comparing the wet year 2003 and the dry year 2001,it is found that the groundwater recharge in wet year is nearly 200 million m3 less than in the dry year,making it impossible to accomplish water diversion target of Zheng yi Gorge,even if the middle reach users use less water.This has led to the phenomenon that“the more abundant of water,the more difficult of completion”.It is recommended to adjust water distribution scheme or increase the regulation and storage engineering works to solve this problem.