The Variation and Effectiveness of Protection Forests in Hualien Coastal Areas

• Main Authors: Lu Li Wei, 盧力瑋
• Other Authors: 黃隆明
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/87660164512379024165

碩士 === 國立中興大學 === 水土保持學系所 === 98 === Abstract This study using Hualien #2618, #2602 and #2635 protection forests as examples to investigate the effects of disaster prevention and environmental features of coastal forests and to plan on the recommendations. Identifying the changes of landscapes in satellite images allows the understanding of the overall changes of protection forests and whether the coastlines are moving backward. The results indicate that grasslands, beaches and dunes, and construction sites are increasing in area, while farming lands and forest zones are decreasing in area, with cemeteries and military sites remaining unchanged. Also, #2602 and #2635 protection forests, the latter being particularly obvious, are removed from the current list as they cannot be restored from partially drown in seawater, adding to the tendency of decreased area of forests. The efficacies of protection forest are analyzed by micro-climate study. The results indicate that the average illumination inside the forest zone is 1/150 of that outside; the solar radiation inside the forest zone is on average 1/5 of that outside. The average temperature outside forest zone is 2.3℃ higher than that inside in summer and 0.4℃ higher in winter. The average atmospheric pressure inside forest zone is about 2mb higher than that outside and the relative humidity inside the forest is shown to be comfortable. The wind speed inside the forest is as low as most zero. All these suggest that the protection forest zones really suit an ideal location for wind-proof, escape from summer and winter as well as natural recreation. Many studies conducted in Taiwan and overseas are summarized and indicate that a forest zone brings about best protection when it has a 10-row width with a C-shaped cross-section. And a forest zone in two sections, one at the front, the other behind, each with 20 rows and an interval of 15H (H: average tree height) not only can increase the energy insulating effect but also saves more land. To mitigate the damages caused by typhoon, it is recommended to plan on setting up tide-water control forest the front of #2618 Protection forest zone. Its width should be 30-40 m wide at minimum, consisting of shrub zone at the front, coppice zone that grows from seeds easily at the middle, and tall tree zone at the rear. It is advisable to extend the earth embankment of Nan-bin Park to be constructed south of the #2602 Protection forest, which will not only retard the striking of intense waves during a typhoon but also keep the strong wind away from protected area more effectively.