Instituto Hondureño de Ciencias de la Tierra, IHCIT, Universidad Nacional Autónoma de Honduras, Tegucigalpa, Honduras.
Department of Earth and Environmental Sciences, University of Texas at Arlington, 500 Yates Street, Arlington, TX 76019, USA.
Sci Total Environ. 2022 Oct 20;844:156941. doi: 10.1016/j.scitotenv.2022.156941. Epub 2022 Jun 24.
The inter-mountainous region of central Honduras has been experiencing abrupt urban drinking water shortages during the last decade. Land use fragmentation and rainfall deficits have rapidly reduced surface water quality and quantity in this region. Here we present a 3-yr (2018-2020) tracer study within the headwaters of the Choluteca River basin (2949 km). We sampled rainfall (weekly N = 156; daily N = 270), drilled wells (N = 166; up to ~300 m depth), boreholes (N = 70; ~4-12 m depth), and springs (N = 128) to assess the spatiotemporal connectivity between rainfall and mean groundwater recharge elevations (MREs). Clear W-shaped incursions characterized rainfall isotopic seasonality from the dry to the wet season. Air mass back trajectory analysis revealed three primary moisture sources: 73 % (east, Caribbean Sea), 17 % (southwest, Pacific Ocean), and 10 % (north; Gulf of Mexico). Groundwater sources exhibited a strong meteoric origin with evidence of secondary evaporation evolution, characterized by low d-excess values. MREs for the drilled wells ranged from 821 to 2018 m asl with a mean value of 1570 ± 150 m asl. Seasonal isotopic variability during dry-wet transitions and the influence of rapid infiltration limited the performance of the MRE method in springs and boreholes. MREs coincided primarily with coniferous forests, pasture, and crop areas, within regions of moderate to high transmissivity. These results are intended to guide the mapping and delineation of critical recharge areas in central Honduras to enhance municipal water regulations, effective environmental protection, and long-term conservation practices.
中洪山地的水资源短缺问题
中洪山地的水资源短缺问题
过去十年，洪都拉斯中部山区经历了突发性的城市饮用水短缺问题。土地利用碎片化和降雨量不足导致该地区地表水水质和水量迅速下降。在此，我们呈现了一项为期三年（2018-2020 年）的示踪剂研究，该研究地点位于乔卢特卡河流域的源头流域（2949 平方公里）。我们对降雨（每周采样 N = 156；每日采样 N = 270）、钻孔水井（N = 166；深度可达约 300 米）、钻孔（N = 70；深度约 4-12 米）和泉水（N = 128）进行了采样，以评估降雨与平均地下水补给高程（MRE）之间的时空连通性。降雨同位素季节性表现出明显的 W 型入侵特征，从旱季到雨季。空气团回溯轨迹分析揭示了三个主要的水汽来源：73%（东部，加勒比海）、17%（西南部，太平洋）和 10%（北部；墨西哥湾）。地下水源具有强烈的大气成因特征，并有二次蒸发演化的证据，表现为低 d-过剩值。钻孔水井的 MRE 范围从 821 到 2018 米，平均为 1570 ± 150 米。旱季和雨季过渡期间的季节性同位素变化以及快速入渗的影响限制了 MRE 方法在泉水和钻孔中的应用。MRE 主要与针叶林、牧场和作物区相吻合，这些地区的透水性处于中等至高透水性区域。这些结果旨在为洪都拉斯中部地区的关键补给区进行测绘和划定提供指导，以加强城市水资源管理、有效环境保护和长期保护实践。
