Abstract
摘要：集水區之土地利用及水文現象皆為空間分佈，而景觀生態主要是以時、空間尺度研究土地利用組成之空間要素、結構、變化與其間相互作用，本計畫以景觀生態學為基礎，整合景觀生態面向之土地利用變遷模式及空間分佈式水文模式於地理資訊系統，探討集水區土地利用變遷對生態水文產生之衝擊。本計畫第一年依研究區域五堵集水區之土地需求及空間政策，訂定土地利用策略，並以景觀生態指數為優化之目標函數，應用退火演算法求取最佳化之土地利用空間格局，並探討優化與經驗性土地利用模式CLUE-s動態模擬之土地利用各情境格局之差異性。本(97)年度研究重點在整合景觀生態面向土地利用變遷模式與分佈式水文土地植被模式(DHSVM)，進行集水區水文量變化之模擬。由於現今模擬土地利用變遷對於集水區水文量時空變化影響，多為非動態模擬，而實際土地變遷過程為動態的改變，而無法進一步準確地對於生態水文的衝擊進行模擬評估，因此本計畫承襲第一年研究結果，運用經驗性土地利用模式CLUE-s，依據農地釋出政策及開發空間限制對土地利用變遷影響，產生4種情境，於時間上劃分動態逐次開發與非動態一次完全開發，依據土地變遷模擬結果給定DHSVM土地利用(植被)參數，進行水文量變化情形之模擬。土地利用變遷模擬結果顯示，空間限制政策包含限制森林區與山坡地保育區”之情境2與情境4，整體景觀空間分佈呈現較僅限制”限制森林區”之情境1與情境3聚集，有較好的功能可維持集水區連續性與生物棲地完整性。水文變化模擬結果顯示，農地釋出政策造成集水區出流處平均流量增加之影響；而空間限制政策影響下，限制範圍較大的空間限制情境一，其開發較為集中，尤其集水區上游區域，其平均流量上升幅度較空間限制情境二高。此外，相同的模擬情境下，動態開發結果相較於非動態一次完全開發對於集水區水文衝擊較低，亦較符合實際情形。整體而言，情境3之結果衝擊最小為最佳。
綜合上述，景觀生態學上土地利用較佳之結果，其水文分析結果，以涵養水資源角度而言卻非最佳，未來可對最佳生態水文土地利用空間策略進行探討，以優化土地利用模式之模擬結果進行水文量變化模擬，在目標函數的設計上應考量同時兼顧景觀生態與生態水文，以得到最佳生態水文土地利用空間策略與情境，求取一景觀生態與生態水文雙贏局面。
Abstract: Land use, land cover and hydrological components are all spatial distributed in watersheds. The landscape ecology, dealing with the interactions between spatial pattern and ecological processes, perspective offers great benefits when analyzing land cover changes as part of an ecosystem on spatial and temporal scales. The purpose of this research is to develop an integrated spatial distributed model for watershed planning and management based on integrated spatial distributed concept and framework integrating optimal land use change model in landscape dimension, and a spatial distributed hydrological model into a geographical information system. During the first year of this project ,we have evaluated land use demands and spatial policies, and defined land use strategies for the Wutu watershed. Moreover, the optimal land use change model in landscape dimension has been developed by using landscape metrics, simulated annealing and empirical land use change model. During this year ,we have successfully integrated empirical land use change model (CLUE-s) and a distributed hydrological Model(Distributed Hydrological Soil Vegetation Model,DHSVM) and modeled the hydrological influences caused by the dynamic process-based land use change simulation under the four scenarios designed for agriculture conversion policy and spatial constriction policy in Wutu watershed.
The results revealed the dynamic process-based land use change simulation which caused smaller hydrological impact is more reasonable for real case simulation .The agriculture conversion policy caused the higher hydrological impact and scenario 2 and 4 designed for strictly spatial constriction have the better potential to improve the spatial coherence of land-use functions contrast to scenario 3 designed for flexible spatial constriction but which has the smaller hydrological impact .In the future, this study recommends to consider the hydrological impact and landscape indices in objective function of the optimization model simultaneously.
Keyword(s)
土地利用模擬
景觀生態
空間格局
空間分佈式水文模式
最佳化
空間分佈
整合性空間分佈模式
Land use change simulation
Landscape ecology
Spatial Pattern
Spatial distributed hydrological model
Optimization
Spatial distributed
Integrated Spatial Distributed Model
