摘要
陆源地下淡水排泄(SFGD)作为海底地下水排泄(SGD)中的重要组成部分,也是陆地向海洋输送化学物质重要且隐蔽的通道。将宾州州立集成水文模型PIHM应用到广东省东南部沿海地区,构建海岸地表水-地下水耦合模型,对SFGD速率进行时空变异分析,结果表明:(1)SFGD速率与相关影响因子的多元回归分析显示当地形坡度i≤2%时,地形坡度是SFGD速率的主控因子,地形坡度越大,SFGD速率越大,当i>2%时,SFGD速率与各影响因子均无显著相关。(2)研究区域子流域之间SFGD速率差异主要是流域形状以及地形差异造成的,螺河流域片区海岸线短且沿海地区主要为平原地区,因此年均单位长度SFGD速率小。(3)在主要降雨事件中,SFGD比地表径流对降雨的响应更快,峰值出现时间比地表径流平均早1~3 d。利用地表水-地下水耦合模型研究SFGD速率的时空变异规律为海底地下水排泄估算提供了新途径,为未来沿海生态管理规划提供了科学参考。
Submarine fresh groundwater discharge(SFGD)is an important component of the submarine groundwa-ter discharge(SGD)flux and a significant pathway of chemical transport from continents to oceans.To analyze the spatial and temporal variations of SFGD using the surface-subsurface coupled model,we applied the physics-based,fully-coupled,distributed hydrologic model Penn State Integrated Hydrologic Model to coastal areas in the south-eastern part of the Guangdong Province.Results showed(1)higher SFGD rates offshore of the steep terrain and lower SFGD rates downgradient of low-lying areas.Multiple regression analyses were conducted between relative factors and SFGD,and the results showed that the topographic gradient(i)predominantly controls the SFGD rates when i≤2%.By contrast,there are no significant correlations when i>2%.(2)The differences in SFGD rates between the subbasins are mainly affected by the shapes and topography of the watershed.The SFGD rates of the Luo River basin are less than those of other areas because of its shorter coastline and flatter terrain.(3)The peak value of SFGD flux often appears one-three days earlier than runoff during major precipitation events.The coupled sur-face-subsurface modeling method is a promising method for the estimation of SFGD,with important scientific ref-erences for coastal ecological management.
作者
罗璐
俞烜
刘丙军
陈晓宏
LUO Lu;YU Xuan;LIU Bing-jun;CHEN Xiao-hong(School of Civil Engineering,Sun Yat-sen University,Zhuhai 519082,China;Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai),Zhuhai 519082,China)
出处
《海洋科学》
CAS
CSCD
北大核心
2021年第9期29-39,共11页
Marine Sciences
基金
广东省水利科技创新项目(2020-27)
广东省“珠江人才计划”创新团队项目(2019ZT08G090)。
关键词
海底地下水排泄
陆源地下淡水排泄
地表水-地下水耦合模型
PIHM模型
submarine groundwater discharge (SGD)
submarine fresh groundwater discharge (SFGD)
coupled surface-subsurface model
PIHM
