周睿, 曲文静, 王超月, 代锋刚, 李方红. 南大港湿地湖水蒸发及地表水地下水转化研究[J]. 中国生态农业学报 (中英文), 2024, 32(0): 1−10. DOI: 10.12357/cjea.20230708
引用本文: 周睿, 曲文静, 王超月, 代锋刚, 李方红. 南大港湿地湖水蒸发及地表水地下水转化研究[J]. 中国生态农业学报 (中英文), 2024, 32(0): 1−10. DOI: 10.12357/cjea.20230708
ZHOU R, QU W J, WANG C Y, DAI F G, LI F H. Evaporation of lake water and exchange of surface water and groundwater in the Nandagang Wetland[J]. Chinese Journal of Eco-Agriculture, 2024, 32(0): 1−10. DOI: 10.12357/cjea.20230708
Citation: ZHOU R, QU W J, WANG C Y, DAI F G, LI F H. Evaporation of lake water and exchange of surface water and groundwater in the Nandagang Wetland[J]. Chinese Journal of Eco-Agriculture, 2024, 32(0): 1−10. DOI: 10.12357/cjea.20230708

南大港湿地湖水蒸发及地表水地下水转化研究

Evaporation of lake water and exchange of surface water and groundwater in the Nandagang Wetland

  • 摘要: 南大港湿地是我国重要湿地之一, 近年来湿地生态环境及其健康状况不容乐观。为揭示南大港湿地不同水体氢氧同位素特征, 湖水蒸发及区域地表水—地下水转化关系, 探究南大港地区水循环过程, 本研究于2023年5月开展河水、湖水、海水和地下水样品的采集与分析。根据同位素分馏和氘盈余估算了湖水的蒸发损失, 通过质量平衡混合模型研究了地表水与地下水之间的转化。结果表明, 南大港地区浅层地下水大多沿当地大气降水线分布, 降水为地下水的主要来源; 受蒸发因素的影响, 地表水体氢氧同位素值普遍高于地下水体。由湖水氢氧同位素回归分析得到湖水蒸发线方程: δ2H=6.1498δ18O−14.774 (n=12, R²=0.9814), 通过氘盈余(d值)估算的湖水蒸发损失为27%~37%。自内陆向沿海, 地下水埋深逐渐变浅, 氢氧同位素值逐渐增大。湖水运移受人类活动影响较大, 湿地东南部是活水来源, 湿地西部和北部水体滞留时间较长, 氢氧同位素值较高, 且d值较小。受北部盐场影响, 湖水西部和北部的Cl浓度普遍高于东部和南部。根据Cl浓度和氧同位素值 建立的混合端元模型得到, 50%的浅层地下水样品位于地下水海水混合线上。湖水在东侧存在渗漏, 但其对浅层地下水的影响范围不超过1 km。分析表明: 南大港湿地湖水从天然降水、南排河和廖家洼渠调水得到补给, 而后通过蒸散发和渗漏等方式排泄。

     

    Abstract: The Nandagang Wetland is important in North China. In recent years, the ecosystem health of this wetland has not been optimal. To explore the water cycle process in Nandagang area, the river water, lake water, seawater, and groundwater samples were collected in May 2023, and analyzed to reveal the characteristics of hydrogen (δ2H) and oxygen (δ18O) isotopes in different water bodies, evaporation of lake water, and the exchange between surface water and groundwater in the Nandagang Wetland, as well as to explore the water cycle process in the Nandagang Wetland. The evaporation of lake water was estimated based on isotope fractionation and deuterium surplus (d value) levels. The exchange between surface water and groundwater was evaluated using the mixing model of mass balance. The results showed that most of the shallow groundwater in the Nandagang Wetland was distributed along the local meteoric water line, indicating that precipitation is the main source of groundwater. The groundwater in the study area was mainly brackish and saline water. The averaged δ18O values of the different water bodies were in the decreasing order of lake water > seawater > river water > shallow groundwater, whereas the averaged δ2H values were in the decreasing order of sea water > lake water > river water > shallow groundwater. The averaged d values were in the increasing order of lake water < river water < shallow groundwater. The δ18O and δ2H values of surface water were generally higher than those of groundwater under the influence of evaporation. Compared with surface water, groundwater had a larger variation in isotope values, indicating that groundwater in different regions are affected to different degrees by surface water. The following evaporation line equation of lake water was obtained through δ18O and δ2H regression analysis: δ2H=6.1498δ18O−14.774 ( n =12, R²=0.9814). If the influence of recharge, leakage, drainage, and transpiration is ignored, the evaporation loss of lake water estimated by the deuterium surplus would be 27%−37%, increasing with a decrease in d value. From inland to coast, the δ2H and δ18O values increased whereas d values of groundwater decreased as the groundwater depth became shallower and evaporation became stronger. The movement of lake water was strongly affected by human activities. The wetland water source comes from the southeast. The water bodies in the west and north of the wetland have longer retention times, higher δ2H and δ18O values, and smaller d value. The northern and western parts of the lake have higher chloride contents owing to the influence of the northern salt ponds. According to the end-member mixing model based on Cl concentration and δ18O value, half of the shallow groundwater samples were located on the mixing line between seawater and inland groundwater. Although there is leakage on the east side of the lake, the extent of leakage affecting shallow groundwater is only within 1 km. The analysis shows that the lake water in the Nandagang Wetland is replenished by precipitation, Nanpai River, and Liaojiawa Channel, and discharged by evapotranspiration and leakage. These research results help us better understand the mechanisms of evaporation and surface water-groundwater exchange and provide a reference on the water resources and ecological protection in the Nandagang Wetland for future studies.

     

/

返回文章
返回