|題名||含水層冷熱水交換與預警模式之研究(2/2) Investigation of cool-hot water exchange mechanism and early-warning model of aquifers(2/2)
|英文摘要||Hot spring is a limited resource. In order to sustainably manage and utilize the hot spring resource, the cool-hot water exchange model is established in this project. With in-situ observation data of hot spring temperature and water level, the model is calibrated and verified, and the relation among precipitation, pumping, change of water temperature and water level is thus built. In addition, the early warning factors for hot spring were assessed and the reasonable cap amount was evaluated. Ziaoxi hot spring area was chosen first for demonstration in 2013, and two additional spring areas were selected to establish the cool-hot water exchange model in 2014. Project achievements are as follows:
1. Selecton of additional spring areas
Two additional spring areas were chosen. Our top selection principle was the numbers of monitoring wells. Second principle was the emergency for evaluation due to possible over-exploitation of hot spring resources. Last principle is if the model could match the production mechanism of hot spring. With those principles, we picked up Sihchong River hot sring area and Suao cold spring area for demonstration this year. In addition the simulation of hot spring water level and temperature, simulation of water quality in Suao was attempted to test the applicability of our model.
2. Backgound and data collection
In order to conceptualize and build the cool-hot water exchange model, information such as geography, weather, hydrogeology, land use, historical and present hot spring usage, hot spring sign investigation, and monitoring, were collected for Sihchong River hot sring area and Suao cold spring area.
3. Conceptual model
The construction of conceptual model relied on the collected geological condition, spring flow direction, distribution of spring temperature, and previous researches associated with the study areas. Thereby, the conceptual model serves as solid foundation for building the cool-hot water exchange model.
4. Construction of cool-hot water exchange model
The same modeling developed in 2013 was employed and applied to Sihchong River hot sring area and Suao cold spring area this year. Precipation induced infiltration was simulated by SWAT, and groundwater flow and transportation were simulated by SHEMAT. In addition, due to the installation of water meter and latest claim of hot spring usage by local hot spring enterprises, the model for Ziaoxi is updated. The number of monitoring wells used for calibration and verification in Ziaoxi, Suao, and Sihchong River were 6, 1, and 4 respectively.
5.Reasonable cap amount estimation
The Hill method regarding change of water level and water temperature was applied to estimate the reasonable cap amount of spring water for three areas. Results are compared to the present legal cap amount.
6. Risk factors assessment
Tow risk factors, infiltration and pumping, were analyzed for their influence on spring water level and temperature as following tables. Besides, the effect of risk factors on water quality of Suao cold spring area was insignificant.
7. Effect on vertical temperature gradient
Pumping could result in change of vertical temperature gradeitn for different depth. In Jiaoxi, pumping could lead to slight rising of vertical temperature gradient; in Suao, gradient in shallow aquifer could decline due to pumping and vice versa; gradient in Sihchong River showed insignificant effect from pumping.
8. Symposium for model propaganda
For sharing model results and technology transfer, a symposium for model propaganda was held in GIS NTU Convention Center on Octobor 13th, 2014. Tow sessions were provided, and one is presenting the overall result of the “Investigation of cool-hot water exchange mechanism and early-warning model of aquifers” project. The other is a lecture on the concept and operation of the cool-hot water exchange model.
As a whole, the proposed cool-hot water exchange model could provide the hot spring associated personel in public or private sectors with insightful assessment of pumping and infiltration effect on spring water level, temperature and quality. Thereby, sustainable management of hor/cool spring resources could be achieved.