臺中供水集水區內之降雨總量及空間分析

Abstract

中文摘要 本報告主要以臺中做為缺水的主要研究地區，由於2020年臺灣梅季節短促雨情不佳，接著颱風季沒有颱風登陸或接近，且受反聖嬰現象等因素影響2021年春雨為有正式紀錄以來的最低值，因此水庫蓄水量持續下探，而西半部水庫陸續進入警戒下限，其中中部部分地區更於4月初開始限水措施。本報告針對石岡壩水庫、鯉魚潭水庫等主要供應臺中地區水源之水庫進行分析，並配合集水區內的雨量站降雨資料進行比較，以呈現缺水的狀況。 操作流程先蒐集兩水庫集水區內之雨量站，並利用IDW等雨量線法畫出石岡壩及鯉魚潭集水區之等雨量線圖，接著將等雨量線圖轉換成點的分布，計算集水區內每個點上之降雨體積並加總，探討水的供應量變化。 本報告經計算結果分析，相較於2018年及2019年，2020年所供應臺中之總水體少了很多，且從降雨量以及供水量的比例顯示出2020年極少的降雨量， 而這也是後續到2021年全臺鬧水荒的實證。

Abstract This report used Taichung as the main research area of water shortage. Due to the short rain report in the plum rain in 2020, there was no typhoon landfall or closed distance following the typhoon season. Affecting by factors such as the El Niño-Southern Oscillation, the rain in 2021 had the lowest value since the official record. Therefore, the storage capacity of reservoirs continued to drop, and some reservoirs gradually entered the lower warning limit, and some central and some areas began to implement water restriction measures in early April. This report analyzed the water source reservoirs in major areas such as Shigangba Reservoir and Yutan Reservoir, and compared them with the data of the rain gauge stations in the water catchment basket to understand the water shortage. First,the operation procedure was to lead the rainfall rain station of the two reservoirs' catchment volume, and used the IDW isohyetal method to draw the isohyetal line charts of the Shigang and Liyutan catchment areas, and then converted the isohyetal line charts into the distribution of points, and calculated the first vein of the catchment. The continuous supplied and summed up, exploring the changes in the water supply. According to the analysis of calculation results in this report, compared with 2018 and 2019.The total water body of Taichung suppliers in 2020 was much less, and the ratio of volume to volume results showed that there would be very few visits in 2020,and this was the sound of water shortages across Taiwan in 2021.