【作者】 丁文晖；

【导师】 张勃；

【作者基本信息】 西北师范大学 ， 自然地理学， 2006， 硕士

【摘要】 黑河流域是我国西北干旱区的重要组成部分，处在我国三大自然地理区域交汇过渡地带，是环境演化的敏感区域和生态脆弱带，土地利用/覆盖变化的水文效应在时空上具有差异性，土地利用变化对流域地下水系统的作用与区域地下水资源的时空变化有着显著影响。干旱区的水资源特性决定了地下水通常是干旱区重要的水源，地下水资源往往成为维持干旱区绿洲生命的首要因素。研究区以典型的农业经济为核心，83％以上的农业经济集中在绿洲区域，这种典型的绿洲经济格局，使水资源与土地利用间的关系更加密切。土地利用方式对地下水资源有着显著的效应，改变了地下水系统的天然循环路径和方式。土地利用变化的各种过程不仅决定地下水的补给部分，而且也决定着地下水的水质状况。利用研究区68眼动态观测井20年观测数据在ArcGIS中进行插值分析，地处干旱区内陆平原的河西走廊黑河干流中游地区地下水位处于区域性持续下降过程中，下降幅度自南部山前的大于0.5m/a逐步递减到泉水溢出带的小于0.1m/a；研究区土地利用变化导致地下水储存量平均减少了0.55×10⁸m³/a；矿化度从黑河出山的洪积扇带的不足500mg/L到正义峡附近的超过2100mg/L。中游由于长期土地资源的开发，矿化度增幅显著，造成水质变劣，从Ⅰ类水变化成为Ⅲ类水，局部地区甚至达到Ⅳ类水；水体盐化程度加重，由HCO₃^-型水向SO₄^2-或Cl^-型水转化，因此，未来水环境状况不容乐观。从研究结果来看，本区地下水系统脆弱，在人类活动胁迫下脆弱性加剧。土地利用方式影响地下水系统循环路径，水质有恶化趋势。认识土地利用/覆盖变化与流域地下水系统的关系，可以建立有利于地下水保护、合理开发的土地利用模式，促使流域水土资源利用规划与管理更加科学与合理。更多还原

【Abstract】 Heihe river basin is an important part of arid land in north-west region, locates at transition of three physical geography zone, it is sensitive and eco-fragile region of environment evolution. The hydrological effect of land use/cover change shows great spatial-temporal heterogeneity, the land use/cover changes have significant effect on groundwater system and regional water resource. The water resource characteristics of arid region leads that the groundwater play an important role in arid area, and the groundwater resource becomes one vital factor to oasis system. In the study area, the agriculture economy is the core of oasis economy, 83% of agriculture economy is limited in oasis zone. This typical oasis economy structure impels more compact relationship of water resource and land use forming.Land use has significant effect on groundwater resource, and the land use changes the natural hydrologic cycle way of groundwater system. All the processes of land use effects not the groundwater recharge, but also the groundwater quality. In this paper, the author use data from 68 wells to analyze the groundwater variation by using Arc-GIS technique in recent 20 years. The groundwater level is in continual decreasing duration, the decreasing rate is from above 0.5m/a at the foot of southern mountain to 0.1m/a at spring spillover area progressively; the land use change leads that groundwater reserves decreases 0.55×10⁸m³/a averagely in this region; and because of the historical land resource exploration, the groundwater mineralization has significant amplitude, it increases from 500mg/L at the alluvial fan to 2100mg/L near Zhengyi gorge, and the groundwater quality changes from I to III, even reaches IV in some area; water salinization also increases accordingly, it changes from HCO₃^- type to SO₄^2- or Cl^- type, the future water environment is not optimistic. The study results indicate that the groundwater resource system in this region is fragile and become more exacerbating under human activities. The land use pattern has influence to the cycle way of groundwater system, and the groundwater quality shows badness trend.Understanding the relationship between land use/cover change and region groundwater system can help us to set up one land use mode propitious to groundwater protection and reasonable utilization, can impel plan and management of water and land resources using more scientific and rational in Heihe midstream region.更多还原