Groundwater sustainability assessment in coastal aquifers

Journal of Earth system science

A Mahesha2¹  U A Lathashri1² 

[1] Department of Applied Mechanics & Hydraulics, National Institute of Technology Karnataka, Surathkal, Mangalore 575 025, India$$;Department of Civil Engineering, Manipal Institute of Technology, Manipal, Udupi 576 104, India$$

关键词: Coastal aquifer;    seawater intrusion;    SEAWAT;    freshwater;    solute transport;    MODFLOW;   

DOI  :  

学科分类：天文学(综合)

来源: Indian Academy of Sciences

【 摘 要 】

The present work investigates the response of shallow, coastal unconfined aquifers to anticipated overdraft conditions and climate change effect using numerical simulation. The groundwater flow model MODFLOW and variable density groundwater model SEAWAT are used for this investigation. The transmissivity and specific yield estimated from the existing database range from 10 to 810 m^2/day and 0.08% to 10.92% respectively. After successful calibration with Nash–Sutcliffe efficiency greater than 0.80, the values of horizontal hydraulic conductivity and specific yield of the unconfined aquifer were set in the range 1.85–61.90 m/day and 0.006–0.24 respectively. After validating the model, it is applied for forecasting the aquifer’s response to anticipated future scenarios of groundwater draft, recharge rate and sea level rise. The findings of the study illustrate that saltwater intrusion is intensified in the area adjoining the tidal rivers, rather than that due to the sea alone. Of all the scenarios simulated, the immense negative impact on groundwater quality emerges due to overdraft conditions and reduced recharge with the areal extent of seawater intrusion exceeding about 67% (TDS>1 kg/m^3). The study also arrivesat the conclusion that, regional sea level rise of 1 mm/year has no impact on the groundwater dynamics of the aquifer.

【 授权许可】

Unknown