| Summary: | 碩士 === 國立中興大學 === 水土保持學系所 === 106 === We combined the techniques of gravimetry and electrical resistivity tomography (ERT) to estimate the specific yield value at Xinmin area in Minzhu Basin. From September 2016 to September 2017, five of the gravity survey missions and three of the ERT survey missions were carried out in the study area. For the gravity survey missions, the FG-5 absolute gravimeter was used to collect gravity data at the office of the Xinmin village, the Sheliao junior high school, and the Xinmin pumping station. For the ERT survey missions, the data were collected along the 13 survey lines set up on the north shore of the Jhuoshuei River to measure the groundwater level variations in the area. In addition to gravity and ERT survey missions, we also used the gravity integral method to simulate the change of soil moisture in the unsaturated layer and the gravity effect caused by the change of groundwater level. The result of the specific yield estimation was well compared to that from the pumping test conducted by the Xinmin pumping well in June 2017. This study shows that the estimated specific yield value is 22.7% in a stable weather condition, and 47.3% in a rainy weather condition. However, the estimated specific yield value in a rainy weather condition is reduced to 27% to 30% if the soil moisture change is corrected by 15%~20%.
|
|---|
