HYDROLOGY AND CHEMISTRY OF GROUNDWATER AND SEASONAL PONDS IN THE ATLANTIC COASTAL-PLAIN IN DELAWARE, USA
HYDROLOGY AND CHEMISTRY OF GROUNDWATER AND SEASONAL PONDS IN THE ATLANTIC COASTAL-PLAIN IN DELAWARE, USA
复制标题
DOI：
10.1016/0022-1694(93)90048-e
复制
发表时间：
1993-01-01
影响因子：
6.4
通讯作者：
SHEDLOCK, RJ
中科院分区：
文献类型：
--
作者：
PHILLIPS, PJ;SHEDLOCK, RJ
通过研究森林覆盖的滨海平原流域地下水与地表水的关系，研究了小型季节性池塘的水化学特征。对装有自动水位记录仪的一系列井的地下水位变化的观察表明，地下水位配置与盆地地形之间的关系是季节性变化的，特别是对泉水补给的响应。此外，在这一研究区域，地下水位并不像人们通常认为的那样，是陆地表面地形的低调表现。在夏季和秋季，在分隔季节性池塘的沙质山脊下会有一个地下水位槽。最大地下水位高度在干涸池塘底部的沉积物中占上风。当池塘在冬季充满水时，最大地下水位高度会转移到与季节性池塘相邻的高地边缘地带。池塘阶段的增加与春季陆缘水井的瞬变地下水位丘的发育有关。与季节性池塘相邻的小型局部水流系统的重要性也体现在高地边缘浅层地下水与季节性池塘水的化学成分的相似性上。高地边缘和地表水样品的pH值较低(一般小于5)，含有大量的溶解铝(一般超过100g L-1)，低碳酸盐浓度(2 mg L-1或更少)。相比之下，地表含水层中没有经历瞬时堆积的部分具有较高的pH值和较大的碳酸氢盐浓度。这些结果表明，要了解季节性积水湿地的水化学，需要深入研究邻近的浅层地下水流动系统。
The hydrochemistry of small seasonal ponds was investigated by studying relations between groundwater and surface water in a forested Coastal Plain drainage basin. Observation of changes in the water table in a series of wells equipped with automatic water-level recorders showed that the relation between water-table configuration and basin topography changes seasonally, and particularly in response to spring recharge. Furthermore, in this study area the water table is not a subdued expression of the land surface topography, as is commonly assumed. During the summer and fall months, a water-table trough underlies sandy ridges separating the seasonal ponds. and maximum water-table altitudes prevail in the sediments beneath the dry pond bottoms. As the ponds fill with water during the winter, maximum water-table altitudes shift to the upland-margin zone adjacent to the seasonal ponds. Increases in pond stage are associated with the development of transient water-table mounds at the upland-margin wells during the spring. The importance of small local-flow systems adjacent to the seasonal ponds also is shown by the similarities in the chemistry of the shallow groundwater in the upland margin and water in the seasonal ponds. The upland-margin and surface-water samples have low pH (generally less than 5.0), and contain large concentrations of dissolved aluminum (generally more than 100 mug l-1), and low bicarbonate concentrations (2 mg l-1 or less). In contrast, the parts of the surficial aquifer that do not experience transient mounding have higher pH and larger concentrations of bicarbonate. These results suggest that an understanding of the hydrochemistry of seasonally ponded wetlands requires intensive study of the adjacent shallow groundwater-flow system.