頁籤選單縮合
題名 | 濱海地區拘限含水層之參數檢定=Parameter Identification in Confined Costal Aquifers |
---|---|
作者姓名(中文) | 徐年盛; 李家彰; | 書刊名 | 農業工程學報 |
卷期 | 50:4 2004.12[民93.12] |
頁次 | 頁28-38 |
分類號 | 443.67 |
關鍵詞 | 拘限濱海含水層; 參數檢定; 優選模式; Confined coastal aquifer; Parameter identification; Optimization model; |
語文 | 中文(Chinese) |
中文摘要 | 本研究之目的在於建立一套兩階段之參數檢定法,以便藉由分析潮汐觀測水位與觀測井觀測水位來檢定濱海地區拘限含水層之流通係數T與蓄水係數S。本研究令含水層沿海岸之邊界為y軸且為無限延展,而x軸則由0延展至無窮遠,因此含水層之流域為一半平面。本研究另外假設此一靠近海邊的拘限含水層為均質、等向且等厚。本研究中,沿海岸之邊界為y軸且為無限延展,而x軸則由0延展至無窮遠,因此含水層之流域為一半平面。本研究另外假設此一靠近海邊的拘限含水層為均質、等周且等厚。本研究中,沿海岸邊界之潮汐波動為正弦波,且起始水位為Ferris(1951)之解昕解。 本研究於第一階段中首先在不抽水情況下,利用傅立葉頻譜分析之方法對潮汐觀測水位與觀測井觀測水位進行分析以求得潮汐效率和延遲時間,然後利用Ferris(1951)之解析解求得蓄水係數與流通系數比值S/T之猜測值,再代入第一階段之優選模式進行參數檢定工作,以找出參數比值之最佳值。 本研究於第二階段中則首先同時收集抽水試驗時之潮汐觀測水位與觀測井觀測水位,然後利用第一階段已求得之參數比值S/T之最佳值以及Ferris(1951)之解析解計算無抽水時潮汐對觀測井水位之影響部分並由觀測井之觀測水位中扣除以得到改正後之觀測井水位。本研究最後則將改正後之觀測井水位以及第一階段所求得參數比值之最佳值代入第二階段之優選模式以求得其個別參數T與S之最佳值。 本研究將所發展之方法應用於一些擬之含水層並獲得收斂之結果,然後將所發展之方法應用於受噪音干擾之觀測資料以驗證其穩定性。 |
英文摘要 | Using field observations of tidal level and piezometric head at an observation well, this research develop a two-stage parameter estimation approach for estimating the transmissivity T and storage coefficient S of a confined aquifer in a costal area. While the y-axis coincides with the coastline, the x-axis extends from zero to infinity and, therefore, the domain of the aquifer is assumed to be a half plane. Other assumptions include homogeneity, isotropy and constant thickness of the aquifer. The boundary condition is a sine curve and the initial head distribution is the analytical solution of Ferris (1951). In the first stage, fluctuations of the tidal level and piezometric head at the observation well are collected simultaneously with out the influence of pumping. Fourier spectra analysis is used to find the autocorrelation and cross-correlation of the two sets of observations as well as the phase vs. frequency function. The tidal efficiency and time delay can then be computed. The analytical solution of Ferris (1951) is then used to compute the ratio of T/S. An optimization model is used to obtain the optimal value of T/S. In the second stage, the system is stressed with pumping and observations of the tidal level and pizometric head at the observation well are collected simultaneously. The effect of tide of the observation well without pumping can be computed by the analytical solution of Ferris (1951) based upon the identified ration of T/S and is deducted from the piezometirc head observations to obtain the updated pizeometric head. Theis equation coupled with the method of image is then applied to the updated pizeometric head to obtain the T and S values. The developed approach is applied to a hypothetical aquifer. The results obtained show convergence of the approach. The robustness of the developed approach is also demonstrated by using noise-corrupted observations. |
本系統之摘要資訊系依該期刊論文摘要之資訊為主。