Minipiezometers Application Improvements on Hydraulic Conductivity Estimation for Quantifying Hyporheic Flow

• Main Authors: Yu-HsuanLin, 林于玄
• Other Authors: Jian-Ping Suen
• Format: Others
• Language: en_US
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/70871034087561299730

碩士 === 國立成功大學 === 水利及海洋工程學系 === 104 === In recent years, hyporheic zone is getting more and more attention either on the water quality investigation or the quantification for a variety of application. Some people considered hyporheic water as a new water source for our water usage which not only provides a stable and clean water resource but can be able to soothe the problem of water supply during dry season. The other people concentrated on the influence of hyporheic flux to the ecosystem. Both two approaches raise an issue of the quantification upon hyporheic flow, however, there are a few studies took efforts on quantifying the subsurface water. This study provides a hyporheic conductivity estimation approach different from Baxter et al. (2003) which we employed in the past to specifically connecting the geometry and approaching a more reasonable quantification. Moreover, we employed the method established by Bouwer and Rice (1976) to simulate the effective radius for specifically separated the spatial difference. The improvements of hydraulic conductivity measuring are necessary while applying our method in field survey. In addition to apply a more effective and efficient field survey process, we used video recording to improve the hydraulic conductivity measurement and analyzed the required components by divided the videos into 33 frames per seconds. Therefore, the first 0.35 seconds cannot be used in the beginning of the video because of the influence of gravity. Thus, we made a suggestion for the video should longer than one second to eliminate the gravity effect. For the measured errors, we also concluded that the most significant component is the head, , in the minipiezometer while measuring vertical hydraulic gradient (VHG). Moreover, we introduced some applications for further research which are going to apply the hyporheic flux quantification. Consequently, these approaches and recommendations may provide a convenient and cost-efficient way to quantify the hyporheic flux more specifically. Through the application examples, it can also be used for different design of piezometers or wells. The hydraulic conductivity of an aquifer can be calculated from the drop of water level in the minipiezometers after a slug of water is added. We expect the further researches can apply our approach to quantify the surface and subsurface interaction.