Abstract
Under the situation of global warming, the prolonged drought and extreme floods caused by climate change have triggered the water and biogeochemical cycle dynamics in the forest watershed system. This study analyzes the long-term meteorological and hydrological monitoring data in Fushan and Lianhuachi areas to understand the frequency and pattern of extreme climate in forest . The dry and wet seasons and heavy rainfall events are also discussed. Changes in flow characteristic, flow component, nutrient concentrations and budget. hence, a scenario projection would be proposed after global temperature raised. Research results are helpful for future environmental change assessment, water resources deployment and mountain flood control, and serve as an important reference basis for forest management and disaster prevention management. Traditionally, the monitoring of collapsed ground must be equipped with monitoring instruments on the collapsed slope, which consumes a lot of manpower, material resources and funds. On the other hand, the occurrence of collapse often results in the interruption of the road or the steep slope of the collapse, resulting in the inability of personnel to reach and erect monitoring instruments, the current situation of the collapsed site, and the immediate response measures to be formulated. Due to the rapid development of unmanned aerial vehicles and aerial photogrammetry instruments, replacing unmanned aerial vehicles with traditional manpower for surveys can save labor costs, overcome the disadvantage of difficult terrain and difficult to reach, and with the characteristics of high mobility, can Continuous monitoring for multiple periods to understand the dynamics of changes in the collapsed area. The development of monitoring instruments and drones has become smaller and more refined, and the functions are becoming more and more diverse. Therefore, the implementation method of this work project is to use unmanned aircraft system with aerial photogrammetry technology, cooperate with on-site geological survey, use aerial photos and integrate UAV aerial survey information to obtain multi-period, high-resolution spatial data, and carry out large-scale spatial scale. The investigation of the collapsed area of the watershed can effectively reduce the cost of the investigation of the collapsed area, and can be used to analyze the collapse mechanism and the potential location of the collapsed area. The purpose of the work project of studying on the selection of artificial restoration tree species and effectiveness monitoring in the collapsed area is to speed the succession of landslide by artificial restoration, so as to prevent intensive rains from causing more serious disasters. Before artificial restoration, we should first understand the current vegetation condition of the landslide area, such as succession stage, dominant trees and seedling composition, whether the seed source is sufficient, and whether the microenvironment is suitable for seedling establishment, etc., in order to evaluate suitable restoration species. Therefore, the plan is to establish the guidelines of "the timing of artificial restoration in the landslide and the selection of tree species". At the same time, monitor the effectiveness of the two ways of artificial restoration methods of staking and sowing in rills, and seedling transplanting. This project will compare the survival and growth of trees in the two artificial ways, and will compare the feasibility for restoration of different trees. The above result could serve as the basis for the artificial restoration methods and tree species selection in the future landslide. There are two problems to be solved in this work project. The first is the choice of restoration tree species in landslide. This should be combined with the existing trees, seed sources (seed rain and soil seed bank) and seedlings in the landslide area to assess the regeneration nature of the inherent trees in the landslide. We have to power the restoration of the poor-regenerating tree species. The second is the monitoring of the effect of artificial restoration, comparing the survival and growth of the trees in the two restoration ways: staking and sowing in rills after three years of the landslide, and seedling transplanting after nine years of the landslide. We will also evaluate whether the selected restoration species is appropriate. Most of the past landslide vegetation studies in Taiwan have focused on the formation of landslide land in the early stage of succession within three years. There are few studies to explore the dynamic process of tree regeneration in the formation of landslide land over 10 years. Therefore, this project provides natural and artificial restoration situation of 10year landslide, these result can be used to predict the forest appearance of the landslide to succession in the medium to long term, which can be used as reference for forest management and forestland planning. The expected benefit of this project is to form the standard model for the artificial restoration of trees in landslide, including timing of restoration, assessment of methods and selection of tree species, which is expected to enhance the effectiveness of the introduction of woody plants in the landslide by Soil and Water Conservation Bureau and Forestry Bureau, and Reduce the risk of frequent natural disasters. Future climate scenarios forecast the humidity contrast between wet and dry seasons and the prolonged duration of the no-rains days. The increasing population of hiking in high mountains compounds the risk of wildfire of those areas. The empirical relationship of fuel moisture between Yushan cane, the dominant species in high mountains and 10-hour fuel sticks and weather elements can help predict the ignition probability. This project aim to design the instrument for fuel moisture observation of those two type of fuels and provide the prediction functions for risk preparedness.