本研究利用雷達資料在時間與空間的高解析特性，以描述雷達估計降雨在空間上的分佈，發現以石門集水區15個雨量站而言，其地面雨量站雨量與雷達降雨率之相關係數，大致落於0.4-0.7之間，且其回波有修正5-7dBZ 現象；而以台北市區13個雨量站，則其相關係數大約為0.6-0.8之間，而回波有修正3-5dBZ現象。 首先利用空間統計方法，計算石門水庫集水區及台北市各網格之降雨量，以描述地面降雨分佈。本研究發現各種空間統計方法，通常都只採用網格點與雨量站之距離作為分析依據，因此所描述之降雨空間分佈特性也較接近。 之後使用雷達回波換算量結合地面雨量站方法，計算石門集水區及台北市之各網格之降雨量。結果顯示，以各種雷達回波配合地面雨量站之方法計算之二十五小時總量都較地面雨量站使用空間統計方法所計算之總量為高，其主要原因為不論以任何空間統計方法估計集水區總量，最大網格降雨量一定發生於地面雨量站所在網格，而最強雷達回波發生位置不一定位於雨量站上方。 The purpose of this study is to investigate the high resolution of radar data in space and time to describe the spatial distribution of radar echo estimated rainfall. The correlation between rainfall rates retrieved from radar echo and ground-truth measured from 15 gauge station of Shiemen watershed was found to be in a range of 0.4 to 0.7;and the radar echo was corrected 5 to 7dBZ. For the 13 rain-gauge in Taipei, the correlation was found to be in a range of 0.6 to 0.8;and the radar echo was corrected 3 to 5dBZ. To calculate the grid rainfall in Shiemen watershed and Taipei was firstly applied by spatial statistic methods to describe the distribution of rainfall. The results show that the characteristics of rainfall distribution was similar from the spatial statistic methods based on the distance between the grid point and the rain-gauge to analyze. Then, total rainfall amount estimated by several radar-rainfall integrated gauge station is higher than that the rain-gauge data adopting spatial statistic methods. The reason was the maximum grid rainfall always on the grid of the rain-gauge by applying statistic method, while the strongest radar echo observed was not necessarily on the spot of the rain-gauge.
