The Characteristic and Classification of Hot Springs in Thailand

Abstract

There has not any proper hot spring management in Thailand yet. This could post some serious problem on improper management of hot spring sites, where its environment has been put into jeopardy. This study aims to provide a way to classify the hot springs in Thailand. The result of this study help in the classification of hot spring sites for official planning improvement of administration and sustainable development of natural resources of the country.
The study makes use of the Department of Mineral Resources (DMR). GIS data of a total of one hundred and fourteen hot springs in the attempt to set up a classification system of hot springs in Thailand. These data include surface temperature, conductivity, alkalinity, acidity, TDS, pH values, H2S, Ca, Cl, F, Fe, K, Mg, Mn, Na, NH3, SiO2, SO4 contents, their locations, usages and other relevant information.
The surface temperature of hot springs are between 32oC - 99oC and SiO2 geothermometer shows estimated reservoir temperature range from 73 o C - 202 o C. Most of the water from these hot springs are relatively transparent, colorless and their composition is sodium bicarbonate. The hot springs in the northern part of the country generally exhibit high SiO2 and F content; strong smell of sulfur. The reverse is true for those located in the southern part of the country. In addition, there are nine hot springs located next to the sea show high concentration of Cl, Ca, Na, K and Mg.
There are three major criteria used in the classification system in this study, temperature, pH and their usage. On the basis of temperature, there are two classes of hot springs in Thailand: hyperthermal spring (62 %, 50-99o C); thermal spring (38%, 30-50o C). There are three classes achieved on the basis of pH values: 68 % of hot springs exhibit weak alkaline (7.5-9), 24% shows neutral (6-7.5) and 8% are alkaline (9-10) springs. There are 4 types of usage classification: power plant, Tourism, consumption and unutilized. There is only 1 geothermal power plant (300 kW binary cycle) in the north of the country. About 43% are used in tourism, about 17% is for consumption and 39% is unutilized.