| 摘要: | 台灣位於變形帶前緣，區域內強烈的地表作用孕育出多樣的地表特徵。氣候的變化與區域內土地利用及水源調配使近地表的水、熱及質量交換機制更趨複雜。石門水庫集水區位於大漢溪上游，離庫後的河水向北轉匯入淡水河出海而不經桃園台地，水庫運轉50年來每年約有55%水源供給桃園台地水資源。跨域引水灌溉與台地上超過數千埤塘，形成特殊地表特徵，此特徵影響台地區域及其下游海岸帶區域關鍵區的陸氣間水熱動力交換與特性；此外，快速都市化過程同時也連帶影響著下游近海岸帶的沉積與環境污染問題。瞭解區域熱、水及質量平衡與其動力特性，是釐清氣候變化及土地利用行為對地表作用影響的重要基礎。本研究整合國內水文、土地利用變遷、社經發展、水文地質、地球物理、陸表過程、大氣科學、氣候領域等研究能量，以監測、調查與模式分析的方法提出整合型計畫：「桃園台地都會與海岸帶關鍵區之時空特徵跨域鏈結研究」。第一階段為期三年的研究，以大漢溪流域及桃園台地與下游海岸帶為研究區域，從觀測、試驗及模式分析各面向，企圖釐清幾個科學議題：(1)過去50年及未來的水資源調度如何改變流域水文循環特徵；(2)台地區域短流河道沖蝕與沉積物的產出與輸送如何影響下游及近海岸帶長期沉積特徵；(3)台地的微氣候如何因水資源調度或地表利用而發生改變；(4)氣候變遷與極端天氣如何改變這個區域的陸表與大氣間的能量與水氣交換過程；(5)過去與未來的土地利用改變，如農地減少、都會區與遊憩休閒等大型開發計畫，如何衝擊區域的水資源循環特徵以及陸表動力過程；以及(6)台地上土地利用改變如何衝擊台地及下游海岸帶水量交換並影響近岸水質污染。本計畫亦將透過國際資訊連結嘗試引進關鍵概念與技術，釐清桃園台地都會與海岸帶關鍵區中，因土地利用與水源調配造成之地表特徵變遷與近地表水、熱及質量交換特性。研究成果除了可以重建過去地表演化、土地利用與氣候變遷相關影響機制；也可以量化未來氣候與人為活動影響下，台地與海岸帶地形地貌以及水文條件所受之影響。 ;Locating in the deformation fronts, the intensive land processes have created landscape diversity over the island of Taiwan. The land processes and geomorphology associate with the climate variations, land-use dynamics, and water resources allocation can further enhance the complexity of land surface water, heat and mass interactions. Reservoir Shihmen has been operated over 50 years and is located at the upstream of Daham River. A total of 55% reservoir outflow is allocated out of the Daham River Basin to support irrigation and industrial/domestic water usages at the Taoyuan tableland. The trans-basin water allocation and thousands of irrigation ponds over the Taoyuan tableland create unique landscape characteristics in Taoyuan tableland and the downstream coastal zones. Such intensively managed landscapes, regions of significant land use change, serve as sources of economic prosperity. However, the intensity of land use change is responsible for unintended deterioration of our land and water environments in Taoyuan tableland. Understanding the dynamics of water, heat, and mass interactions and dynamics in the area is fundamental to clarify the influences of landscape evolution on heat, water, and mass transport in critical zones in Taoyuan tableland and coastal areas. The interdisciplinary research project links the research efforts in the fields of landscape evolution, social-economic development, hydrology, atmospheric, geology, and geophysical sciences. The proposed three-year integrated project: Trans-disciplinary research on characterizing spatio-temporal variations of critical zones in Taoyuan tableland and coastal areas, aims to integrate innovated observatory, experiment, and modeling techniques for the Taoyuan tableland and coastal areas. The objectives of the project are to clarify the following key issues: (1) the impact of the past and future water allocation on the watershed characteristics, (2) the influence of short rivers on the regional sediment erosion and deposition; (3)the effects of land use and water allocation on the meteorological variations in tableland area, (4)the influences of climate variations and extreme weather on heat and water interaction processes between land and air interfaces, (5) the impact of past and future land use on the hydrological characteristic and near surface dynamics of heat and water interactions, and (6) the influences of land use in tableland on the interactions of heat, water, and mass transport in the critical zone of coastal areas. The research tasks relevant to the issues are expected to clarify and quantify the dynamics of heat, water, and mass exchanges in the critical zones (between the atmosphere and shallow aquifer) with modified landscape induced by water allocation and human activities in Taoyuan tableland. |
