The effective evaluation of the achievement of the goals set by the "Implementation Plan for Closure and Relocation of Publicly-owned and Legal Water Wells within 3 Kilometers Along the High-speed Railway in Yunlin County" (hereinafter referred to as this plan) approved by the Executive Yuan, the Ministry of Economic Affairs (Water Resources Administration), 2005 On August 11, the Ministry of Economic Affairs approved the "Public and Legal Water Well Closure and Relocation Implementation Plan Implementation Effectiveness Monitoring Plan within 3 kilometers along the high-speed rail line of Yunlin County", to summarize the annual work results submitted by each implementation unit and study the effectiveness monitoring The report is to grasp the benefits of improving the stratum subsidence of the Yunlin section of the high-speed rail after the implementation of this plan.
In addition to the establishment of the environmental monitoring system and the construction of new water channels in conjunction with the closure and removal of public water wells, the improvement of trunk and branch lines and the installation of water measuring equipment for water wells, water wells within 3 kilometers should be disposed of. Yunlin Farmland Water Conservancy Association 69 wells, 16 from Taiwan Water Supply Company, and 2 from Taiwan Sugar Company, a total of 87 public water wells. The scheduled work content and expected drainage reduction benefits for each year are listed as "The project is within 3 kilometers of the project. "List of well disposal plans and implementation status" is shown. According to the content of the plan, the cumulative number of disposals of publicly-owned legal water wells within 3 kilometers of each implementing unit by 2007 should be 19 sealed wells, 37 deactivated, and 21 retained (enhanced monitoring); According to the results of the work submitted by the executive unit, the 1996 plan for the disposal of publicly-owned legal water wells within 3 kilometers, and the actual sealing and filling of 20 wells as of March 2008 (including the completion of the 1997 plan for the completion of the planned sealing of 10), 21 deactivated, 19 detained (strengthened monitoring), the cumulative number of various disposals is actually 29 sealed wells, 39 deactivated, and 19 detained (strengthened monitoring), which are in line with the approved plan for the closure of the relevant water wells this year Work content requirements.
According to the elevation detection data, the maximum annual average subsidence rate in Yunlin area in 2007 was 8.2 cm/year, and the continuous subsidence area was 552 square kilometers. Compared with the maximum annual average subsidence rate before the implementation of the plan, which was 11.6 cm/year, continuous subsidence was observed. The area is 679 square kilometers, which shows that after the implementation of the project, the stratum subsidence has continued to slow down, and the degree of subsidence along the high-speed rail has also continued to decrease. In addition, according to the statistical analysis of the groundwater observation network in Taiwan, the water level of the groundwater observation wells in Yunlin area in 2008 compared with that before the implementation of the plan, 54% showed a rebound or level, and those along the high-speed rail showed a rebound or level. 57%, indicating that after the implementation of the plan, the groundwater level has shown a trend of picking up. The groundwater level within 3 kilometers along the Yunlin section of the high-speed rail has rebounded more significantly.
The amount of groundwater pumped by the Taiwan Water Company within 3 kilometers along the high-speed rail line in 2007 was 1,717,852 cubic meters, which was a reduction of 2,856,123 cubic meters compared to before the implementation of this plan (refer to "The reduction in the implementation of public water well closure in 1996 Achievement table"). The planned sealing of 2 wells was completed in 1995 (reduction of 2.92 million cubic meters of water rights). The total groundwater pumping volume of the planned closure of 10 wells in 1996 was 51,615 cubic meters, which was already lower than The reserved maintenance operation volume (2,000CMD) of 730,000 cubic meters roughly meets the requirements of the approved plan for the deactivation of pumping wells this year; the Yunlin Farmland Water Conservancy Association has pumped 1,905,195 cubic meters of groundwater within 3 kilometers along the high-speed rail in 2007. 996,280 cubic meters less than before the implementation of this plan. From 2006 to March 2008, the total amount of water rights for 27 wells was 39.7 million cubic meters (13 newly drilled within 3 kilometers) The amount of water rights for wells was 19.61 million cubic meters), which actually reduced the amount of water rights for wells by 20.09 million cubic meters; Taiwan Sugar Co., Ltd. retained (strengthened monitoring) 2 wells within 3 kilometers along the high-speed rail line, which continued this year Only Huwei No. 2 Well is pumped. However, the total annual pumping volume in 2007 was 582,581 cubic meters, which is an increase of 517,140 cubic meters compared to before the implementation of this plan. In total, the annual pumping consumption of groundwater within 3 kilometers along the high-speed rail line by the above-mentioned implementation units in 2007 has been reduced by approximately 3,335,263 cubic meters (a reduction of pumping 44.2%) compared to before the implementation of this plan, and the amount of water rights for wells has been reduced by 23.01 million Cubic meters.
Although the implementation of this plan has positive effects on the groundwater level rise and the stratum subsidence rate in the implementation area, it is still necessary to pay special attention to the continuous decline of the annual groundwater level of the 2nd-2 aquifer within 3 kilometers of the high-speed rail line. In addition to continuous monitoring to clarify the relationship between the groundwater level and the changes in stratum subsidence, the implementation area should also include the Yunlin Farmland Water Conservancy Association (No. 566, No. 579, No. 580, No. 650, No. 283) and Taiwan Sugar Company ( Huwei No. 2) A total of 6 pumping control wells located in the depth of the aquifer are listed as the current focus of prevention and control work. In addition, the special area of Huwei that has been abnormally subsided in recent years and the intersection with No. 78 expressway should continue to be closely monitored. In addition, although Taiwan Sugar Corporation's increased water consumption in 1996 compared with the previous plan was still in line with the approved water rights and only accounted for 3.11% of the total water consumption in 1996, it violated the spirit of the plan. Considering that the groundwater level of the 2-2 aquifer (the water layer where the pumping depth of Well Huwei No. 2 is located) in this area is showing a continuous downward trend, Taiwan Sugar Company should formulate countermeasures such as the displacement of the organic farming area development zone as soon as possible and implement them. In order to reduce the amount of groundwater pumped in the project area in accordance with this plan, the Ministry of Economic Affairs will continue to track the situation in 2008.
Regulation of groundwater