全球氣候變遷造成台灣年降雨日數減少,降雨量分布不均,每逢颱風豪雨帶來短時間強降雨量,常導致中南部沿海地層下陷區,因海水倒灌及雨水宣洩不易而汪洋一片;內陸山區則因地勢陡峭、河川逕流,儲水不易,造成土石流災害頻傳,然至枯水期則每有缺水、限水景況。由於各種自然及人為因素,使得台灣水資源的儲存與調配利用更加困難。此刻,水足跡的計算便可讓政策制定者對於台灣目前整體水資源使用狀況有清楚的掌控。國際水足跡網站(WFN)針對水足跡定義,包含了水資源使用量及污染程度兩種面向之衝擊評估,水資源耗用與能源及溫室氣體議題亦有很大的關聯性,透過台灣水足跡概況的瞭解,將有利於決策者進行永續性評估。本研究以縣市為層級,透過藍水足跡的計算,初步探討台灣各縣市水資源的使用狀況,以利有效了解各縣市水資源使用現況,並協助未來各縣市政府配合中央進行節水政策,有效管理水資源。
Global climate change has caused the decreasing number of annual rainy days and uneven rainfall distribution in Taiwan. Moreover, typhoons frequently cause heavy rainfall in a short time and often lead to flooding in central and southern coastal Taiwan. In the mountains and slopeland areas, due to the steep terrains and heavy runoffs, typhoons have caused frequent landslides and debris flows. On the other hand, in the dry seasons, Taiwan faces severe water shortages and limited water use. Due to natural and human factors, Taiwan's water storage and deployment have become more difficult. Consequently, the examination of water footprint can provide policymakers and the society a clear vision of the current overall water use. The Water Footprint Network defines the water footprint to include the impact assessments of two dimensions: water resource use and water pollution level. There are strong relationships among water consumption, energy use and greenhouse gas emission. The examination of Taiwan's water footprint can help policymakers and the society assess the degree of sustainability. This paper explores water consumption among five municipalities and seventeen counties in Taiwan, through the blue water footprint calculations. The goal is to help local and central governments propose appropriate water-saving policies to effectively manage Taiwan's water resources and further to move towards sustainability.