Simulated Salt‐Water Movement in the Nakhon Luang Aquifer, Bangkok, Thailand

Analytical and numerical modeling procedures based on the hydrodynamic dispersion were used to analyze the salt‐water contamination problem in the Nakhon Luang aquifer underlying the City of Bangkok. A preliminary evaluation is performed for the approximate locations of the contaminating sources, and its rate and pattern of encroachment are predicted under different operating conditions in the future to assist in planning an efficient and economic monitoring network. The contaminating source is widespread and is located on the western side of the Chao Phraya River. With the present trend of pumping, the rate of encroachment is greatest from the northwest direction towards the main pumping center. The study indicates the advantage of performing one‐dimensional model analysis prior to attempting two‐dimensional regional analysis, particularly in cases where the initial chloride concentration distribution is unknown.