The karst critical zone monitoring network (1): Tropical karst in WanBaDan,Thailand

The karst critical zone monitoring network (1): Tropical karst in WanBaDan,Thailand

2018-4-15

Highresolution recording of WanBaDan spring’s behavior during the whole hydrologicyear

Fig.1 Location of WanBaDan study area

Compare toSouthwest of China’s karst, the underground rivers in the tropical karst areaof Thailand have different behavior during the complete hydrological year. Dueto the uniform rainfall, the aquifer is dominated by dolomite, the hydrologyand water chemistry is relatively stable, and the storage capacity also isstrong. It is different from the limestone aquifer in the Southwestern of Chinakarst area:sensitive to rainfall input, sharp ups and downs. At the same time,due to high temperature, good vegetation coverage, high soil CO₂concentration,relatively uniform dolomite aquifer, long interaction time between groundwaterand rock, strong dissolution, resulting in higher spring water Conductivity, Ca²⁺and HCO₃^-concentration.

Fig.2 Introduction board of WanBaDanmonitoring station to the public

Fig.3Sensors,dataloggers and batteriesinstalled inside the monitoring box

Fig.4 High resolution recording ofhydro-chemical parameters in whole hydrological year from Nov.2015 to May.2017with time interval of 15 minutes at WanBaDan monitoring station, SaiYork,Kanchunaburi, Thailand

Utilizationof high resolution of automatic recording,we’ve obtained the complete datasetduring whole hydrological year at WanBaDan monitoring station, SaiYork,Kanchunaburi,Thailand. From previous study of PhuToej spring and WanBaDan,lithological and climatic condition,well vegetation cover were found to be maincontrol factors ,compared with the typical monitoring stations in the karstarea of Southwestern China. Influenced by vegetation conditions, relativelyuniform rainfall in the tropical monsoon climate zone, which is only dividedinto dry season and rainy season. The aquifer is mainly dolomite, generallydeveloped as karst spring, and its hydrology and water chemistry is relativelystable, and its storage capacity is strong, unlike karst of SW China. In thearea dominated by limestone, due to the concentrated rainfall in May-August,heavy storm are frequent. Underground river is sensitive to rainfall,especially the storm. Discharge of the underground is upset and the storagecapacity of aquifer is poor.