植被对矿区地下水位变化响应研究

发布时间：2018-06-15 05:27

本文选题：地下水位 + 数值模拟　；参考：《煤炭学报》2017年01期

【摘要】：依据地下水浅埋区植被蒸腾对地下水位变化十分敏感的特征,构建沙柳根系吸水条件下的水流方程,分析生态脆弱矿区植生长对地下水位下降幅度的阈限。通过原位监测获取气象要素、土壤水、地下水与沙柳蒸腾量的动态变化规律,建立地下水变化与植被蒸散发关系数值仿真模型并对模型进行求解,模拟沙柳蒸腾对煤炭开采区地下水位变化的响应。研究发现:沙柳的日蒸腾量有受气象要素控制的特点,并在正午12时前后出现2次极值,水位越浅变化越显著。地下水对沙柳蒸腾的贡献值随着地下水位埋深的增加而减少,当地下水位埋深15 cm时,贡献率为100%;地下水埋深215 cm时,贡献率为0。在地下水浅埋区,地下水是沙柳蒸腾的主要水源,潜水埋深超过215 cm后地下水不再对沙柳生长提供水源,这也是沙柳对煤层开采地下水位下降的阈限。
[Abstract]:According to the characteristics that vegetation transpiration is very sensitive to the change of groundwater level in shallow groundwater area, the water flow equation of Salix willow under the condition of water absorption by root system is established, and the threshold of plant growth to the decrease of groundwater level in ecological fragile mining area is analyzed. Through in-situ monitoring, the dynamic changes of meteorological elements, soil water, groundwater and evapotranspiration of Salix willow were obtained, and the numerical simulation model of the relationship between groundwater change and vegetation evapotranspiration was established and solved. The response of Salix willow transpiration to the change of groundwater level in coal mining area was simulated. It is found that the diurnal transpiration of Salix davidii is controlled by meteorological elements, and there are two extreme values around 12:00 at noon. The shallower the water level is, the more obvious the change is. The contribution of groundwater to the transpiration of Salix wilfordii decreased with the increase of the buried depth of groundwater level, and the contribution rate was 100 when the groundwater level was 15 cm, and the contribution rate was 0 when the groundwater depth was 215 cm. In shallow groundwater area, groundwater is the main source of transpiration of Salix willow. When the depth of groundwater buried is more than 215 cm, the groundwater will no longer provide water source for the growth of Salix, which is also the threshold of the decrease of groundwater level in coal seam mining.
【作者单位】：长安大学环境科学与工程学院;长安大学旱区地下水文与生态效应教育部重点实验室;陕西省地质环境监测总站;
【基金】：国家重点基础研究发展计划(973)资助项目(2013CB227901) 陕西省科学技术推广计划资助项目(2011TG-01)
【分类号】：TD823

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