雨水管理估算方法之應用與土地使用規劃

App11ed Stormwater Management Calculating Methods for land Use Planning

傳統之土地使用規劃作業多未考慮地區之水文特性，及其與土地使用間之因果關係，因此，排水系統計畫往往為土地使用計畫之事後配合措施。由於都市化現象對地表水文影響甚鉅（例如：地表積水、下游地區之洪害、水質污系等），故有雨水管理（Stormwater Management）專門學問之演發。雨水管理專門學問研完主要內容為：（一）建立估算地表逕流水量與水質之方法；（二）研究、發展控制地表逕流之方法。其中估算方法之建立、發展與應用，不但為雨水管理研究之基本工具，亦為整合土地使用計畫與排水計畫所不可缺少之一環。本文首先介紹國內外較常應用於估算地表逕流水量與水質之方法，再經由對傳統土地使用規劃作業缺失之檢討，研提應用雨水管理估算方法於整合土地使用計畫與排水計畫之過程及功效。其應用層面主要包括三者：（一）分析土地使用發展強度；（二）制定土地使用績效標準；（三）評估土地使用對水文程序之影響。經由此三者之操作，土地使用計畫將可與排水計畫相互配合，且地區水文體系亦本再因人為之土地使用與開發，而產生不平衡現象。

The hydrologic characteristics of land resources and the interrelationships between land use changes and hydrologic consequences have frequently been neglected by the traditional land use planning process. Too often, land use plans are followed by the planning and design of drainage system in order to alleviate the adverse effects caused by the proposed land use alterations. The primary purposes of stormwater management are: (1) to develop methods for calculating quantity and quality of storm runoff; and (2) to research and develop techniques for controlling runoff. The major aims of this paper to introduce methods have been frequently applied in estimating storm runoff volume and quality and to propose techniques for integrating concept of innovative stormwater management with land use planning process. The techniques discussed in this paper include: (1) the analysis of land use intensity allowed based on the hydrologic carrying capacity; (2) the establishment of land use performance standards; and (3) the evaluation of the effects of land use changes on the rainfall-runoff processes.