| 摘要: | 地下水資源為台灣地區重要之供水來源之一,其中地下水資源較豐沛之濁水溪沖積扇與屏東平原沖積扇近年來均已超限利用,甚而導致嚴重之地層下陷與地下水環境劣化等議題。雖然地表水與地下水之交互水體傳輸密不可分,但其水文特性卻存在極大差異,加上台灣地區降雨時空豐枯不均且新水源開發不易且受限,如何有效運用地表水與地下水資源的不同時空尺度之水文特性,為維持水資源永續經營之首要任務。 本計畫 105 年度以濁水溪沖積扇與屏東平原為研究區域,首先針對屏東平原進行水文循環分析,針對近 10 年之豐枯水年期分析屏東平原水文循環(降水、河川水位、地下水等)特性,探討地下水對降水之時空變化特性,以及分析地下水對水文極端事件之敏感度;接著進行人為抽取地下水之衝擊性評估,利用整合地表地下水數值模擬工具,模擬屏東平原在完全無人為抽取地下水干擾之長期地下水變動趨勢,以年際尺度(10 年以上)之無人為抽水模擬成果比較現有實際觀測地下水位,探討人為抽取地下水之長期影響特徵;接著再以季節性預報在地下水管理應用之角度,使用前兩年所建置之整合性地表、地下水 WASH123D 數值模式, 結合季節性預報(未來 1 至 3 個月)結果,分析濁水溪沖積扇與屏東平原枯水期地下水資源管理應用策略;最後則是針對屏東平原海水入侵進行評估,使用屏東平原地下水數值模式,探討屏東平原豐枯水期之海水入侵時空變化差異,協助屏東 平原地下水海水入侵相關議題防治規劃。 ;Groundwater is one of major water resources in Taiwan. Due to over pumping of groundwater for past decades, both Zhuoshui River Alluvial Fan and Pingtung Alluvial Plain have been facing critical issues of land subsidence and degradation of groundwater environments. Although subsurface water and surface water are naturally linked in view of hydrological cycles, great discrepancies in residence times and responses to different hydrological forcing are observed. Rainfall in Taiwan has great spatial and temporal variations and new water resources are difficult to develop due to environmental protections, and thus bring great challenges in water resources of Taiwan. Therefore it is important to develop integrated methodologies for taking advantages of various spatial and temporal characteristics of surface water and subsurface water to meet the requirement of sustainable development in water resources. Both Zhuoshui River Alluvial Fan and Pingtung Alluvial Plain are considered in this year (2016) of study. We will first analyze characteristics of hydrological processes of the Pingtung Alluvial Plain in the past 10 years for revealing groundwater and surface water responses to various hydrological forcing including fluctuations of groundwater levels in response to extreme rainfalls. We then apply WASH123D model to investigate effects of long-term anthropogenic pumping on groundwater by comparing simulated groundwater levels without any pumping with observed groundwater levels for the past 10 years. Another task is to integrate seasonal forecasts (lead time of 1~3 months) with WASH123D models of both study areas developed in past two years to facilitating groundwater management during drought events. The last task is to numerically assess seasonal variations of sea water intrusion patterns of the Pingtung Alluvial Plain for supporting the planning and mitigation of sea water intrusion. ;研究期間：10503 ~ 10512 |
