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Hydraulic conductivity (K) is crucial for groundwater studies and is conventionally obtained through pumping tests, which are costly due to well installation, resulting in a limited amount of data. Recent studies have addressed this limitation by estimating K through the integration of a pumping-test K and electrical resistivity measurements. While this approach is suitable for local areas, it cannot readily be applied to determine K fields for the composite fan delta. This study proposes and demonstrates an advanced method to estimate the K’s spatial distribution of a composite fan delta. The proposed method included data classification, linear regression, and kriging interpolation. Data classification was conducted using a physical-based zonation method. The K and formation factor (F) data pairs were classified into several groups. Linear regression was used to develop K-F mapping for each group. The regression results showed a good correlation between K and F in each group. These K-F mappings were verified by additional pumping tests. These results indicate that estimation errors were between 7 m/day and 58 m/day, and the correlation coefficient of each data group was greater than 0.8. Based on these regression equations and ordinary kriging method, the detailed K spatial distribution of the study area was derived. According to these results, the proposed method is efficient and economical to delineate K’s spatial features for regional groundwater systems and can benefit groundwater-related studies.
You-Cheng Chen; Jui-Pin Tsai; Liang-Cheng Chang; Ping-Yu Chang; Helen Lin. Estimating Hydraulic Conductivity Fields in Composite Fan Delta Using Vertical Electrical Sounding. Water 2018, 10, 1620 .
AMA StyleYou-Cheng Chen, Jui-Pin Tsai, Liang-Cheng Chang, Ping-Yu Chang, Helen Lin. Estimating Hydraulic Conductivity Fields in Composite Fan Delta Using Vertical Electrical Sounding. Water. 2018; 10 (11):1620.
Chicago/Turabian StyleYou-Cheng Chen; Jui-Pin Tsai; Liang-Cheng Chang; Ping-Yu Chang; Helen Lin. 2018. "Estimating Hydraulic Conductivity Fields in Composite Fan Delta Using Vertical Electrical Sounding." Water 10, no. 11: 1620.
Ping-Yu Chang; Lian-Cheng Chang; Shao-Yiu Hsu; Jui-Pin Tsai; Wen-Fu Chen. Estimating the hydrogeological parameters of an unconfined aquifer with the time-lapse resistivity-imaging method during pumping tests: Case studies at the Pengtsuo and Dajou sites, Taiwan. Journal of Applied Geophysics 2017, 144, 134 -143.
AMA StylePing-Yu Chang, Lian-Cheng Chang, Shao-Yiu Hsu, Jui-Pin Tsai, Wen-Fu Chen. Estimating the hydrogeological parameters of an unconfined aquifer with the time-lapse resistivity-imaging method during pumping tests: Case studies at the Pengtsuo and Dajou sites, Taiwan. Journal of Applied Geophysics. 2017; 144 ():134-143.
Chicago/Turabian StylePing-Yu Chang; Lian-Cheng Chang; Shao-Yiu Hsu; Jui-Pin Tsai; Wen-Fu Chen. 2017. "Estimating the hydrogeological parameters of an unconfined aquifer with the time-lapse resistivity-imaging method during pumping tests: Case studies at the Pengtsuo and Dajou sites, Taiwan." Journal of Applied Geophysics 144, no. : 134-143.
Chin-Tsai Hsiao; Liang-Cheng Chang; Jui-Pin Tsai; You-Cheng Chen. Features of spatiotemporal groundwater head variation using independent component analysis. Journal of Hydrology 2017, 547, 623 -637.
AMA StyleChin-Tsai Hsiao, Liang-Cheng Chang, Jui-Pin Tsai, You-Cheng Chen. Features of spatiotemporal groundwater head variation using independent component analysis. Journal of Hydrology. 2017; 547 ():623-637.
Chicago/Turabian StyleChin-Tsai Hsiao; Liang-Cheng Chang; Jui-Pin Tsai; You-Cheng Chen. 2017. "Features of spatiotemporal groundwater head variation using independent component analysis." Journal of Hydrology 547, no. : 623-637.
High recharge areas significantly influence the groundwater quality and quantity in regional groundwater systems. Many studies have applied recharge potential analysis (RPA) to estimate groundwater recharge potential (GRP) and have delineated high recharge areas based on the estimated GRP. However, most of these studies define the RPA parameters with supposition, and this represents a major source of uncertainty for applying RPA. To objectively define the RPA parameter values without supposition, this study proposes a systematic method based on the theory of parameter identification. A surrogate variable, namely the average storage variation (ASV) index, is developed to calibrate the RPA parameters, because of the lack of direct GRP observations. The study results show that the correlations between the ASV indexes and computed GRP values improved from 0.67 before calibration to 0.85 after calibration, thus indicating that the calibrated RPA parameters represent the recharge characteristics of the study area well; these data also highlight how defining the RPA parameters with ASV indexes can help to improve the accuracy. The calibrated RPA parameters were used to estimate the GRP distribution of the study area, and the GRP values were graded into five levels. High and excellent level areas are defined as high recharge areas, which composed 7.92% of the study area. Overall, this study demonstrates that the developed approach can objectively define the RPA parameters and high recharge areas of the Choushui River alluvial fan, and the results should serve as valuable references for the Taiwanese government in their efforts to conserve the groundwater quality and quantity of the study area.
Jui-Pin Tsai; Yu-Wen Chen; Liang-Cheng Chang; Yi-Ming Kuo; Yu-Hsuan Tu; Chen-Che Pan. High Recharge Areas in the Choushui River Alluvial Fan (Taiwan) Assessed from Recharge Potential Analysis and Average Storage Variation Indexes. Entropy 2015, 17, 1558 -1580.
AMA StyleJui-Pin Tsai, Yu-Wen Chen, Liang-Cheng Chang, Yi-Ming Kuo, Yu-Hsuan Tu, Chen-Che Pan. High Recharge Areas in the Choushui River Alluvial Fan (Taiwan) Assessed from Recharge Potential Analysis and Average Storage Variation Indexes. Entropy. 2015; 17 (4):1558-1580.
Chicago/Turabian StyleJui-Pin Tsai; Yu-Wen Chen; Liang-Cheng Chang; Yi-Ming Kuo; Yu-Hsuan Tu; Chen-Che Pan. 2015. "High Recharge Areas in the Choushui River Alluvial Fan (Taiwan) Assessed from Recharge Potential Analysis and Average Storage Variation Indexes." Entropy 17, no. 4: 1558-1580.
Typhoon events occur frequently in Taiwan resulting in flood-related disasters. A well-operated reservoir can reduce the severity of a disaster. This study incorporates a genetic algorithm, a river hydraulic model, an artificial neural network and a simulation model of Tseng-Wen Reservoir to propose a real-time flooding operation model. The model includes two parts: an optimal flooding operation model (OFOM) and a reservoir inflow forecasting. Given an inflow condition, the OFOM is run based on the safety of the dam structure, reservoir flooding operation rule, and minimization of the downstream loss due to flood. A simple and robust model for reservoir inflow forecasting, which automatically chooses the most similar event from a typhoon event database as the future inflow, is developed. This study compares the model results with the real operations during Typhoons Sepat, Krosa, Kalmaegi, Fung-wong, Sinlaku, and Jangmi. This study compares the performances of the proposed model with the practical operation operated by the management center of Tseng-Wen Reservoir. The proposed model indicates shorter flooding duration in the downstream area. For example, the flood durations of the model output are 4 and 3 hours shorter during Typhoon Krosa and Sinlaku, respectively, than the practical operations.
Yu-Wen Chen; Jui-Pin Tsai; Liang-Cheng Chang; Chih-Chao Ho; You-Cheng Chen. The development of a real-time flooding operation model in the Tseng-Wen Reservoir. Water Policy 2013, 45, 490 -503.
AMA StyleYu-Wen Chen, Jui-Pin Tsai, Liang-Cheng Chang, Chih-Chao Ho, You-Cheng Chen. The development of a real-time flooding operation model in the Tseng-Wen Reservoir. Water Policy. 2013; 45 (3):490-503.
Chicago/Turabian StyleYu-Wen Chen; Jui-Pin Tsai; Liang-Cheng Chang; Chih-Chao Ho; You-Cheng Chen. 2013. "The development of a real-time flooding operation model in the Tseng-Wen Reservoir." Water Policy 45, no. 3: 490-503.
The hysteresis of capillary pressure versus saturation (P–S) relation is an important constitutive relation in multiphase flow, since the P–S relation is widely used to predict P–S relations in the simulation of the non-aqueous phase liquids (NAPLs). This work examined the performance of the scaling rule on predicting the P–S relationship and then studied the joint impact of the scaling and hysteresis on the multiphase NAPL flow simulation. Various experimental P–S values of distinct fluid pairs were compared with the scaled P–S curves using the scaling rule. The comparison indicated that the prediction of P–S is more accurate when the water–air P–S curve is used to scale other P–S curves. The joint impact of the scaling and hysteresis on the NAPLs flow simulation was then investigated by numerical simulation studies. The NAPL simulator was used to simulate the outcome of several scenarios based on a system with water–NAPL–air in a hypothetical sand tank. For both gasoline and trichloroethylene, the difference of the injected NAPL volume between no hysteretic and hysteretic simulations over a given time period was the smallest when the water–air P–S curve was used to scale other P–S curves. Simulation results of this study are valuable references for predicting the distribution of NAPLs.
Hung-Hui Chen; Liang-Cheng Chang; Hsin-Yu Shan; Jui-Pin Tsai. Joint Impact of Scaling and Hysteresis on NAPL Flow Simulation. Environmental Modeling & Assessment 2008, 14, 715 -728.
AMA StyleHung-Hui Chen, Liang-Cheng Chang, Hsin-Yu Shan, Jui-Pin Tsai. Joint Impact of Scaling and Hysteresis on NAPL Flow Simulation. Environmental Modeling & Assessment. 2008; 14 (6):715-728.
Chicago/Turabian StyleHung-Hui Chen; Liang-Cheng Chang; Hsin-Yu Shan; Jui-Pin Tsai. 2008. "Joint Impact of Scaling and Hysteresis on NAPL Flow Simulation." Environmental Modeling & Assessment 14, no. 6: 715-728.