碩士 / 國立中興大學 / 水土保持學系所 / 103 / The objective of this study focuses on the characteristics of sand fixation in the coastal area. Choosing Yunlin Mailiao for the test area and dividing into two parts the vertical direction of north-east monsoon (the coastal area near to the northwest of embankment) and the parallel direction of north-east monsoon (the casuarina windbreaks) compared the water ratio , particle density , particle size , pH value and angle of repose. Creating the data for the characteristics of sand fixation in that area. Then, selecting the embankment, one of the sand-fixed structures, as the object of study. It’s simulated by wind tunnel about three types of wind speed 8 m/s, 10 m/s and 12 m/s to observe the change of the sand fixation and the PM10 of density after setting the embankment. Using Surfer to draw topographic map and calculate volume change of the sand fixation after aggregating the elevation data of the sand fixation. And then, measuring the density of PM10 for the difference of elevation by TSI DustTrak.
The water ratio of sand in the coastal area vertical and parallel direction of monsoon are 6.80% and 5.80%, particle density is 26.77g-cm-3 and 26.25g-cm-3, both of they are sand, the pH value is 7.74 and 7.28, the angle of repose is 33.1 and 34.6. The property changed unapparent when the sampling location moved by horizontal way, however, when the depth increase, both of the water ratio of sand and the particle density increase, but the pH value decrease in the coastal area vertical direction of monsoon. The particle density decrease and the pH value increase in the parallel direction of monsoon.
By way of wind tunnel experiment, setting embankment. have good effect of Sand Fixation, and the effect of protection decrease as wind speed increase. The PM10 decrease as altitude increase, There is maxima PM10 value on the altitude from 2.5H to 3.5H by setting embankment(H is height of model). And it will create area of dust control behind embankment, area of control‘s altitude height reduce when distance increase. When wind speed increase from 8 m/s to 12m/s, the PM10 value all increase no matter setting embankment or not, however ,percentage of variation of PM10 between setting or not setting embankment. in low wind speed is higher then high wind speed.
| Identifer | oai:union.ndltd.org:TW/103NCHU5080084 |
| Date | January 2015 |
| Creators | Yu-Jeng Chin, 秦宇正 |
| Contributors | 黃隆明 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 91 |
Page generated in 0.0095 seconds