(1. 中南大學(xué) 地球科學(xué)與信息物理學(xué)院, 長沙 410083；
2. 中南大學(xué) 有色資源與地質(zhì)災(zāi)害探查湖南省重點實驗室, 長沙 410083)
摘 要: 利用模擬阻抗網(wǎng)絡(luò)構(gòu)建三維地電模型，方便快速正演計算。采用共軛梯度算法進行最小二乘反演迭代，迭代過程中不必完全計算靈敏度矩陣，大大節(jié)約了計算時間與存儲空間，實現(xiàn)視電阻率監(jiān)測數(shù)據(jù)的快速三維反演計算。在設(shè)計快速三維反演算法的基礎(chǔ)上，利用模擬污染監(jiān)測視電阻率數(shù)據(jù)對算法進行實驗測試。測試結(jié)果表明：基于模擬阻抗網(wǎng)絡(luò)模型的共軛梯度反演算法能有效實現(xiàn)對視電阻率數(shù)據(jù)的反演成像，算法收斂穩(wěn)定，并且計算耗時少。進一步實驗場地的實際監(jiān)測數(shù)據(jù)反演測試還表明：該反演成像方法能有效反映追蹤污染物質(zhì)在地下介質(zhì)中的擴散軌跡與具體影響范圍，具有較好的實用性和時效性。
關(guān)鍵字: 三維反演；視電阻率；共軛梯度；污染監(jiān)測
（1. School of Geosciences and Info-Physics, Central South University, Changsha 410083, China？
2. Hunan Key Laboratory of Non-ferrous Resources and Geological Hazard Detection, Central South University,
Changsha 410083, China）
Abstract:Based on impedances network analogy, 3D geo-electric model was built to perform numerical simulations more quickly. In the least square inversion, the conjugate gradient method was adopted to avoid calculating sensitivity matrix completely, which greatly decreases the time and memory space needed to do 3-D inversions. Then, it is practical to perform monitoring resistivity data inversion effectively to satisfy the requirements of engineering. Synthetic data was used to test the proposed inversion algorithm. The results show that the algorithm can perform resistivity data 3D inversion with fast convergence in short computation time. Further field data tests demonstrate that the fast 3D inversion can make good responses to the motion and range of underground contaminant plumes. And its exactness and effectiveness are very meaningful for interpreting field data in contaminant monitoring.
Key words: 3D inversion; apparent resistivity; conjugate gradient; contaminant monitoring
