Thai Geoscience Journal

Development and Application of Geological Survey Information Technology in CGS

2024-03-29T14:30:51+07:00

Geological informatization has undergone three development periods, namely digitization period, networking period, and intelligence (big data) period. The paper reviewed the role China Geological Survey (CGS) has played in the course and summarized major contributions over the past two decades. For fully utilizing the massive geodata for better supporting social and economic development, CGS conducted research and development of geo-information technologies, such as various software tools by adopting the current popular GIS, database and computer technologies, the upgraded Digital Geological Survey System (DGSS) based on cloud computing, big data and AI application, the national geodatabase system, the model and standard system, and the national geological database-GeoCloud 3.0. CGS also participated in several international cooperative programs, e.g. the Deep-time Digital Earth (DDE) and International Geoscience Program (IGCP), which promoted the progress of geoinformation technology in the world at large. In the new era, CGS has to conquer a series of obstacles to ensure secured data management, high level of data integration, guaranteed data quality and intelligent services.

Triassic radiolarian assemblages from the chert-clastic rock sequences in the Kanchanaburi area, western Thailand

2024-05-01T15:01:18+07:00

Early to early Late Triassic radiolarian assemblages have been identified in the chert-clastic rock sequences in the Kanchanaburi area, western Thailand. These rock sequences consist of well-bedded chert a few centimeters thick alternating with thin-films of shale and interbedded with siliceous shale and sometimes quartz-rich sandstone. The radiolarian assemblages are; the Parentactinia nakatsugawaensis, Eptingium nakasekoi, Triassocampe deweveri, Spine A2 and Muelleritirtis cocholeata assemblages of Early-to-early Late Triassic, which are known from Japan, USA, Russian Far East, European Tethys, northwestern Peninsular Malaysia, Philippines, and several areas in Thailand. The occurrence of the Early to early Late Triassic radiolarians from bedded chert sequences in this area suggests that the Palaeo-Tethys Ocean and Panthalassa Ocean were probably connected by seaways at this time and might have shared the same oceanic circulation system. Forty-five species belonging to 23 genera and five unidentified radiolarians with type A to E of radiolarian spines are investigated. These radiolarian-bearing rocks seem to have been deposited in a hemipelagic environment at the continental slope of the eastern margin of the Sibumasu Terrane. The occurrence of early Late Triassic radiolarians from bedded chert sequences in the Kanchanaburi area indicates that the closure of the Palaeo-Tethys Ocean occurred at least after early Late Triassic time.

Flood hazard mitigation using managed aquifer recharge: Numerical assessment of a pilot trial in the Nam Kam River Basin, NE Thailand

2024-06-06T13:40:31+07:00

Flash flooding is one of the most catastrophic natural hazards. These disastrous events may trigger some rainfall-related geohazards, e.g., landslides and slumps. Sakon Nakhon Province, partly located in the Nam Kam River Basin, has been severely damaged by storm-driven floods. Due to the effect of climate change, precipitation has changed in intensity, pattern, and frequency. In 2017, this area was hit by a tropical cyclone causing heavy rainfall and considerable flash flooding. Consequently, residential properties, agricultural areas, and infrastructure facilities were devastated. The storm eventually caused 3-million-dollar worth of damage in the province.

The challenge for policymakers is to develop strategies that can provide long-term solutions to reduce extensive damage caused by the hazards. This study drew on examples of the use of managed aquifer recharge (MAR) as an approach primarily to prevent flood-related issues and store stormwater runoff. The MAR system comprises settling and infiltration ponds constructed in an area of 8,000 m2 . A modeling approach is widely known as a scientific and reliable method for the assessment of MAR systems. Therefore, a groundwater model was developed to simulate MAR and the subsequent movement of groundwater. The MAR model was constructed using a notable 3D groundwater-flow model known as MODFLOW-NWT, in association with a MODPATH particle-tracking model. The model accounted for interactions between artificial lakes (Lak Package) and groundwater. Two model scenarios were developed based on the actual MAR methods applied at the demonstration site: (1) An infiltration pond scenario and (2) an infiltration pond with four recharge wells scenario.

The results revealed that the flow model had an acceptable accuracy with an NRMSE of 8.98%. The annual rate of pond seepage was 90,052 m3 . Additionally, artificially recharged water simulated by virtual particles could travel in the system for at least ten years, with a maximum travel distance of 698.07 meters (0.19 meters/day). In addition to recharge ponds, the runoff was recharged directly into the aquifer via the recharge wells. An annual recharge rate is about 22,600 m3 . The deeper-and-longer flow paths were roughly doubled in the distance compared to the first scenario, being up to 1,683.16 meters away from recharge wells with an average rate of 0.46 meters/day. In conclusion, the MAR system is a practical solution to capture runoff, mitigate downstream flooding, and enhance groundwater storage for sustainable water management. Most importantly, the system may provide indirect solutions for preventing geohazards within the context of river floods, landslides, and slumps.