Advances of Submarine Groundwater Discharge Studies in South America

Submarine groundwater discharge (SGD) is the hidden portion of water that discharges into the ocean across the ocean-land interface, and it is considered one of the hydrological cycle's major components. Two decades ago, SGD in South America was undocumented, and significant advances on this field has occurred since then. This paper presents the results of SGD investigations, a compilation of the SGD estimations, and the areas lacking of data in South America. The compilation of observed SGD in South America shows that groundwater seepage from the land to the ocean occurs in many environments along the coast. Considering only the few regions for which the total SGD flux was estimated, the SGD flux (ca. 1.2 × 108 m3 day-1) is equivalent in volume to almost 70% of Amazon River discharge. Although the study of SGD in South America has greatly advanced, many uninvestigated sites and key questions remain.

海底地下水排泄（Submarine Groundwater Discharge，SGD）是指通过海陆界面排入海洋的隐性水体，亦是水文循环的核心组成部分之一。二十年前，南美洲地区的SGD研究尚属空白，而此后该领域已取得显著进展。本文梳理了南美洲SGD的调查研究成果、相关估算数据汇编，并明确了该地区尚缺乏研究数据的空白区域。对南美洲已观测到的SGD数据汇编结果显示，海岸沿线多种环境中均存在陆地向海洋的地下水渗流现象。仅针对已完成总排泄通量估算的少数区域进行统计，其SGD通量（约1.2×10^8 立方米/日）的总体积几乎相当于亚马逊河径流量的70%。尽管南美洲SGD研究已取得长足进步，但仍有大量未开展调查的区域及关键科学问题亟待解决。