Shallow Water Table Fluctuations in Relation to Soil Penetration Resistance
Shallow Water Table Fluctuations in Relation to Soil Penetration Resistance
复制标题
浅水位波动与土壤渗透阻力的关系
DOI：
10.1111/j.1745-6584.2003.tb02438.x
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发表时间：
2003
期刊：
影响因子：
2.6
通讯作者：
C. Kendall
中科院分区：
文献类型：
--
作者：
J. Shanley;K. N. Hjerdt;J. McDonnell;C. Kendall
流域的水文建模经常因缺乏地下地层和优先水流区域的信息而受到阻碍。我们评估了土壤渗透阻力的有用性，该土壤渗透阻力可以通过动态锥入度计轻松测量，并结合地下水位波动的测量，作为推断地下流动模式的一种经济有效的方法。在我们位于佛蒙特州 Sleepers River 的现场，渗透阻力在地表 10 至 30 厘米处最低，然后通常在 60 至 80 厘米处增加至局部最大值，我们将其解释为土壤/耕作界面。在此深度以下通常存在耕耘阻力减小的区域，在 1 至 4.5 m 深度处，朝向基岩表面的阻力逐渐或突然增加。穿透阻力与通过保释试验确定的饱和导水率具有微弱但显着的负相关性（r2 = 0.25，p < 0.05）。在许多井中，每月地下水位往往集中在土壤/耕作界面附近的阻力区或略高于阻力区。在抗蚀区上方和下方完成的嵌套井的化学和同位素动力学表明，该区域可能暂时将更深的地下水库与融水输入隔离开来，这可以通过低 δ18O 值清楚地识别出来。在地下水排放区，δ18O 值在整个剖面上趋于收敛。相比之下，即使在混合良好的水域中，溶解有机碳（DOC）也保持着向陆地表面不断增加的浓度梯度，这反映出它从有机层中快速释放。了解土壤渗透阻力对地下水行为的影响可能有助于未来的流域建模工作。
Hydrologic modeling of catchments is frequently hampered by lack of information on subsurface stratigraphy and zones of preferred flow. We evaluated the usefulness of soil penetration resistance, easily measured by a dynamic cone penetrometer, together with measurements of ground water level fluctuations, as a cost‐effective means to infer subsurface flow patterns. At our field site at Sleepers River, Vermont, penetration resistance was lowest in the surfi‐cial 10 to 30 cm, then typically increased to a local maximum at 60 to 80 cm, which we interpreted as the soil/till interface. Below this depth usually lies a zone of decreased resistance in the till, giving way to either a gradual or abrupt increase in resistance toward the bedrock surface at 1 to 4.5 m depth. Penetration resistance had a weak but significant negative correlation with saturated hydraulic conductivity determined by bail tests (r2= 0.25, p < 0.05). At many wells, monthly ground water levels tended to cluster at or just above the resistant zone near the soil/till interface. Chemical and isotopic dynamics in nested wells finished above and below the resistant zone suggest that the zone may temporarily isolate the deeper ground water reservoir from meltwater inputs, which were clearly identified by low δ18O values. In ground water discharge zones, δ18O values tended to converge throughout the profile. In contrast, dissolved organic carbon (DOC) maintained a gradient of increasing concentration toward land surface, even in otherwise well‐mixed waters, reflecting its rapid release from organic horizons. Understanding the effect of soil penetration resistance on ground water behavior may be useful in future catchment modeling efforts.