Most of the areas where stratum subsidence occurs in Taiwan are located in the southwestern coastal areas. The main reason for this is improper land use and the ineffective use of water resources. The "Implementation Plan for the Prevention and Control of Ground Subsidence" has been implemented since November 2, 1995. It has been approved by the Executive Yuan. It is reported that the relevant prevention and control work has been handled in accordance with the original planning schedule. The two goals and five quantified goals of "use, alleviate stratum subsidence" and "rational use of land and water resources, reduce disaster losses, and reduce social costs" have achieved initial results, and have achieved the following two specific results.

 1. The use of groundwater resources has been effectively reduced: The total annual use of groundwater in Taiwan has been reduced from 7.14 billion cubic meters per year before the implementation of the plan to 572.6 billion cubic meters in 1999 ( Among them, the annual use of groundwater in aquaculture fisheries has dropped from 2.4 billion cubic meters before the implementation of the plan to 1.159 billion cubic meters), and the groundwater level in most stratum subsidence areas has risen and the groundwater level has been zero. The line tends to move outward.

2. The subsidence rate of the stratum subsidence area has continued to slow down: In areas with severe stratum subsidence such as Yunlin, Chiayi and Pingtung, the subsidence rate of these areas has slowed down year by year due to effective prevention and control over the years, and the Yilan area has Trending to stop.

However, at the current stage, the annual average pumping amount of groundwater still exceeds 4 billion cubic meters of recharge, and some areas (such as the Dacheng and rural areas of Changhua County) cannot reduce the dependence of local industries on groundwater and effectively prevent groundwater. The over-extraction of the stratum subsidence in this area has not yet been significantly relieved. In addition, for the development of emerging industries or the development of new towns (such as Guanyin Township in Taoyuan County and Xinshi Township in Tainan County), water demand will continue to increase. The illegal extraction of groundwater may worsen, and the monitoring and investigation of stratum subsidence and the establishment of an early warning system should be planned and implemented in time to study and judge the potential of stratum subsidence to prevent the occurrence of stratum subsidence.

This effectiveness review report is a comprehensive review of the implementation effectiveness of the implementation plan for the prevention and control of stratum subsidence at the current stage (1996-1999), reviews and analyzes the problems and difficulties encountered in the promotion process, and specifically studies and proposes improvement suggestions for subsequent prevention and control work. To provide planning and research on the axis, content and schedule of the follow-up promotion of the overall prevention and control work, step by step to curb groundwater over-extraction, relieve ground subsidence, and sustainable and rational use of water and soil resources.