現場研究及理論評估裂隙岩層之水力性質與傳輸現象摘要裂隙岩層水文地質研究與一些重要議題有關;諸如二氧化碳地質封存、核廢料掩埋、溫泉使用、地熱開發。如何調查和描述裂隙網路的水力特性和相關的非費克式溶質傳輸是具實用價值的尖端研究課題。本三年計畫將(1)發展跨孔複井雙封塞微水試驗技術以決定裂隙網路的聯通性及水力傳導係數分布,(2)發展新的微水試驗模式納入裂隙傾角影響,用來分析跨孔複井雙封塞微水試驗資料。微水試驗反應呈震盪變化反映裂隙具高滲透性可連通測試井與鄰近觀測井。本新模式決定測試井與觀測井的震盪水位變化,且進ㄧ步假設裂隙網路具碎形幾何特徵,有非整數水流維度(flow dimension)。(3)執行裂隙岩層示蹤劑試驗以獲得非費克式溶質傳輸穿透曲?資料。(4)發展時間分數階傳輸模式用於分析示蹤劑試驗所得穿透曲?資料和評量相關之非費克式溶質傳輸議題。時間分數階傳輸模式據非局部(nonlocal)特性,故適合分析據非局部特性的非費克式溶質傳輸。所有的跨孔複井雙封塞微水試驗及裂隙岩層示蹤劑試驗均在位於新竹縣尖石鄉的「中央大學裂隙岩層水文地質研究井場」進行。此場址有7 口50 米井;每口井在地表下20 米的風化層設置井管,20~50 米的固結砂岩層則為裸孔。此井場已進行一些初步試驗,暸解其裂隙水文地質及裂隙水利特性,對本計畫所擬工作有直接幫助。 Field Study and Theoretic Evaluation of Hydraulic Properties and Transport Phenomena in Fractured Formations Abstract Hydrogeology in fractured formations is associated with important issues, such as CO2 sequestration, nuclear waste repository, utilization of hot spring, and exploration of geothermal energy. How to characterize the hydraulic properties of a fracture network and how to characterize its associated non-Fickian transport are the state-of-the-art research subjects of practical usefulness. In this three-year project, we will (1) develop a cross-borehole multiple-well double packer slug test (cross-borehole MW-DPST) technique which is able to determine the connectivity and hydraulic conductivity distribution of a fracture network that may consist of discrete fractures of irregular spatial distribution; (2) develop a new slug test model taking into account the dip angle effect for data analysis of the cross-borehole MW-DPST. Oscillatory response is indicative of good permeability of the fracture that connects the wells, and this new model aims at solving oscillatory pressure response in the test well and nearby observation wells. Moreover, this model assumes the fracture network to be of fractal geometry with non-integer flow dimensions; (3) conduct tracer tests in a fractured formation to collect breakthrough curves for the study of non-Fickian transport; and (4) develop a fractional-in-time transport model to analyze the tracer test data and to evaluate issues regarding non-Fickian transport. A fractional-in-time model has the ”nonlocal”property and thus is appropriate for the investigation of non-Fickian transport, which is nonlocal in nature. All the cross-borehole MW-DPSTs and tracer tests proposed will be conducted at the 「Research Well Field for Hydrogeology in Fractured Formations」in 新竹縣尖石鄉. This site has 7 wells; each one is 50-meter deep. Each well is cased from the land surface to 20 meters in the weathered zone, and is left as an open borehole from 20~30 meters in the Cenozoic folded sandstone formation. Some preliminary study has been done to understand the hydrogeology and fracture conditions at the site, which is conducive to the proposed research in this project. 研究期間:9908 ~ 10007