摘要
中国大尺度区域地下水演化研究起源于20世纪90年代中期。在过去10年的研究中，构建了长3500km、高差5000m和跨度2万年的大陆尺度气候一地质环境陆地水系统演化断面，揭示了华北平原地下水形成的古地质环境与古气候演化过程及动因，发现近2万年以来该平原地下水的每一主要补给周期为1000-2000年，而且不同尺度系统间存在自相似性，在突变或灾变事件发生之前存在一个熵值较大的平衡期，可作为预测或判断突变或灾变事件依据之一；近50年来人类活动影响使连续统一的华北平原地下水循环系统演变成局部以垂向运动为主模式。在西北内陆黑河流域，相对百年尺度冷期，地下水补给量减少4．38～7．61亿m^3／a，这种变化与山区降水和气温关联度分别为0．97和0．80，与平原区降水和气温关联度仅为0．43和0．60；人类活动对该流域水循环的影响强度由20世纪50年代的19％、经过60～70年代28％，增至80～90年代的54％，进而导致下游区生态环境严重退化；上述成果实现了数字化和虚拟实现的可视化。
The research of regional groundwater evolution on the continental scale in China originates in the middle stage of 1990s. In study on groundwater evolution since 1993, an evolutive section of climate, geologic environment and water cycle systems was developed on the continental scale with the length being 3500km, the elevation difference being 5000m, and the time spanning 20000 years. In this section, the cause and process of regional groundwater forming in North China Plain were revealed including the evolution process of paleogeologic-environment and palaeoclimate. The results indicate that the groundwater recharge periodicity in the North China Plain is 1000-2000yr and there exists self-similarity in different space scale and different water cycle sub-systems. Before the abrupt or catastrophic events take place, there exists a balance period with higher entropy that can serve as an indication for forecasting or identifying the abrupt or catastrophic events. Affected by human activities for the past 50 years, the uniform and consecutive groundwater flow system in the North China Plain was changed into several partial groundwater flow systems with the flow pattern changed into the vertical direction. In the Heihe river basin, Northwest China, groundwater recharge rate decreased within 4.38 × 10^8 m^3/a to 7. 61 × 10^8m^3/a compared with that in the cold period on centennial scale. The change of groundwater recharge rate is strongly correlated with the precipitation and air temperature in mountain area with correlation coefficients being of 0. 97 and 0. 80, respectively. But this relation is weak in the basin with correlation coefficients being of 0. 43 and 0. 60, respectively. The effect of human activities on basin water cycle is more and more strengthen with the intensity being of 19% in 1950s, 28% during from 1960s to1970s, and 54 % during from 1980s to 1990s, which leads to the ecologic environment degeneration in the lower reaches of Heihe River. Based on the results mentioned above, the digitalization and visualization are achieved.
出处
《地质论评》
CAS
CSCD
北大核心
2006年第6期771-776,共6页
Geological Review
基金
国家自然科学基金资助项目(编号40472126)
国家重点基础性研究项目(2006CB403400)的成果
关键词
区域尺度
地下水演化
基础研究
起源与进展
regional scale
groundwater evolution
basis research
origin and achievement
