Effects of climate and land use changes on groundwater resources in coastal aquifers

• Published in: Journal of environmental management Vol. 80; no. 1; pp. 25 - 35
• Main Authors: Priyantha Ranjan, S., Kazama, So, Sawamoto, Masaki
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.07.2006; Elsevier; Academic Press Ltd
• Subjects: Agriculture; ambient temperature; Animal, plant and microbial ecology; Applied ecology; Aquifers; Biological and medical sciences; Climate; Climate change; coastal water; Coasts; Conservation of Natural Resources; Conservation, protection and management of environment and wildlife; Deforestation; Ecosystem; Ecotoxicology, biological effects of pollution; Environmental conditions; estimation; Fresh Water - chemistry; Freshwater loss; Fundamental and applied biological sciences. Psychology; General aspects; Geologic Sediments - chemistry; Groundwater; groundwater contamination; groundwater recharge; Hydrogen-Ion Concentration; hydrologic models; Land use; land use change; mathematical models; Numerical analysis; Oceans and Seas; precipitation; Salinity intrusion; saltwater intrusion; Seasons; Seawater - chemistry; Soil; soil quality; water balance; Water Movements; water quality; water quantity; water salinization; Water Supply; Climate change; Salinity intrusion; Freshwater loss; Land use; Climate; Loss; Environmental factor; Environmental management; Aquifers; Salinity; Freshwater environment; Aquatic environment; Global change; Climate modification; Ground water
• ISSN: 0301-4797; 1095-8630
• DOI: 10.1016/j.jenvman.2005.08.008

To estimate the freshwater loss in coastal aquifers due to salinisation, a numerical model based on the sharp interface assumption has been introduced. The developed methodology will be useful in areas where limited hydrological data are available. This model will elaborate on the changes in fresh groundwater loss with respect to climate change, land use pattern and hydrologic soil condition. The aridity index has been introduced to represent the variations in precipitation and temperature. The interesting finding is that the deforestation leads to increase groundwater recharge in arid areas, because deforestation leads to reduce evapotranspiration even though it favors runoff. The combined climate and land use scenarios show that when the aridity index is less than 60, the agricultural lands give higher groundwater recharge than other land use patterns for all hydrologic soil conditions. The calculated recharge was then used to estimate the freshwater–saltwater interface and percentage of freshwater loss due to salinity intrusion. We found that in arid areas, the fresh groundwater loss increases as the percentage of forest cover increases. The combined effects of deforestation and aridity index on fresh groundwater loss show that deforestation causes an increase in the recharge and existing fresh groundwater resource in areas having low precipitation and high temperature (arid climates).