昆明盆地浅层孔隙水水位动态变化特征及其影响因素

根据盆地内地下水水位动态曲线特征及其影响条件,将孔隙水年内变化动态划分为灌溉型、开采型和降雨型等三种类型。在时程演变上,近20年来,除少数开采井点水位下降外,区内大多数富水块段地下水位一般变化不大或略有回升。盆地西部、北部地下水水位表现出一种缓慢抬升的过程。而盆地东部边缘和南部呈贡附近地下水受开采影响,水位呈下降趋势。受城市化发展的影响,昆明盆地地下水普遍遭受污染,浅层地下水开采强度在降低,同时,农业用水量也在减少,在一定程度上对区内孔隙水水位抬升有很大影响。然而90年代以来,昆明地区进入一个相对丰水期,降雨量的增加是盆地内孔隙水水位整体抬升的根本原因。

Variation Characteristics of Pore-Water Level in Kunming Basin and the Concerned Influence Factors

According to the variation characteristics and impact factors of groundwater level in the Kunming Basin,the water level variations in a year can be classified into three types: irrigation,exploitation and precipitation.In the recent 20 years,the general variations of water level in majority porewater blocks were not remarkable or showed slightly rise except several exploitation wells.In west and north of the basin,the water level slowed a rising process.In the east edge of the basin and the southern part nearby Chenggong,however,the groundwater level which influenced by exploitation assumed drop tendency.Since the rapid development of urbanization,groundwater was polluted,and exploitation intensity of pore-water decreased,simultaneously,the water supply of agriculture also reduced.All these had a great impact on the water level rise.Since the 1990s,however,precipitation in Kunming Basin was relatively abundant,the increase of rainfall is a significant factor for the porewater level rise in the whole area.