Overall management improvement measures of river sand and gravel mining in Taiwan

摘要

In the recent decade, an average of 84% sand and gravel in Taiwan conies from rivers. Instead of having an overall planning, sand and gravel were mined by individual applications. These sand and gravel raining activities could not meet river improvement goal, and the illegal sand and gravel mining had caused degradation of river bed and exposure of levee foundation, bridge piers, river crossing conduits, even endanger to public safety. The unplanned sand and gravel mining activities could not be predicted during planning of flood control facilities and utilization of river resources, thus rivers can not function as planned. Therefore, the overall stability of river bed is an important issue of river management. This article defines suitable areas and river bed elevations for sand and gravel mining in rivers based upon the results of hydraulic, sedimentation and aggradation/degradation analyses. This article also describes the establishment of an overall management improvement plan for sand and gravel mining activities and the unification of all legal sand and gravel mining companies along a river to mine the sand and gravel according to river improvement plan. According to the plan, the goal of maintaining river resources and river functions can be achieved, the sand and gravel would be mined as planned, government income would be increased by receiving mining fee, the sand and gravel mining companies would be self disciplined and taking the responsibility of river management to terminate illegal mining activities, the sand and gravel resources could be utilized effectively and reasonably, and the river improvement goal could be achieved by means of management. Since 1997, unification of sand and gravel mining companies for nine rivers in Taiwan have been accomplished with significant benefits. Hopefully, the article can provide some valuable information to related agencies.