以遙感探測暨地理資訊系統應用於屏東地區紅樹林碳吸存之可行性研究

Feasibility of Applying Remote Sensing and GIS for Carbon Sequestration of Mangroves in Pingtung County

曾文政(Wen-Jeng Tseng)

指導教授 ： 黃益助 ； 余伍洲

國立屏東科技大學/工學院/環境工程與科學系所/碩士(2009年)

https://doi.org/10.6346/NPUST.2009.00036

摘要

工業革命後大量人為溫室氣體的排放，產生溫室效應使得20世紀以來全球表面溫度上升，對環境影響極大也同時造成生態系極大衝擊，溫室氣體中的二氧化碳CO2，是目前技術最易控制且各國社經環境最易接受的控制因素之一。若要在21世紀末將二氧化碳濃度保持為工業革命前之二倍，則目前全球二氧化碳之排放量即需削減一半以上。我國由於工業開發，能源需求快速增加，造成二氧化碳氣體排放也逐年迅速上升。紅樹林生態系是氣候變遷影響的最早指標(Indicators)，全球紅樹林之分布及區域性生態系造成之影響，乃為目前世界各國政府及環保團體所重視的課題。紅樹林生態系是一種多目標利用系統，可提供高產量及永續生產自然產物。由於土地開發或公共建設破壞，目前世界各國紅樹林面積均迅速減少，台灣四面環海，若能有效利用島沿四周之海岸濕地以復育紅樹綠化方式，可以產生二氧化碳CO2及甲烷CH4等溫室氣體減量效果，對於森林土地面積日益縮減的國內工業界來說，成為應京都議定書的生效，投資二氧化碳CO2減量的另一可行出路。
現實環境中，屏東地區海茄苳紅樹林沿堤岸成條帶型群落，不同於其他區域紅樹林在河海口成團型群落的生長方式。本研究分別以SPOT衛星、福爾摩沙二號衛星及航空遙測等三種影像，以及應用ERDAS及ArcGIS電腦軟體，嘗試以監督型分類(Supervised Classification)及最大概似法(Maximum Likelihood Method)進行研究區之土地覆蓋分類，來評估適合之可行遙測方式，並嘗試應用其中航空遙測紅樹林的常態化差異性植生指標(Normalized Difference Vegetation Index, NDVI)，推估屏東地區海茄苳紅樹林之碳吸存量。
研究結果顯示，感測解析度大於紅樹林生長條帶寬度之SPOT衛星影像，及未附帶近紅(NIR)光譜的福爾摩沙二號衛星影像，不適合應用於屏東地區海茄苳紅樹林之遙感監測；僅高解析且具附近紅光譜影像之航空遙測影像適用該海茄苳紅樹林。根據航空遙測萃取屏東地區紅樹林之NDVI值介於0.226～0.283之間，推估之總碳吸存量為1,491.74ton。惟本研究僅就以遙測評估碳吸之可行性進行討論，未在研究期間內以傳統地面調查生物量方式進行海茄苳樹種碳吸存量之評估作為檢核對照。再經檢視前人紅樹林遙測文獻，其他紅樹林樹種NDVI值介於0.20～0.465之間，顯示本研究所得結果應為可行。

關鍵字

紅樹林 ； 海茄苳 ； 遙感探測 ； 碳吸存

並列摘要

After the industrial revolution, the emission of large amount of green house gases resulted in the green house effect, which has increased the global surface temperature in the 20th Century. It has great impact on the environment as well as the ecological system. Among the green house gases, carbon dioxide (CO2) could be easily controlled by present technology and is one of the controlling factors that can be accepted socio-economically by several countries. In order to maintain the amount of CO2 at a level which is twice the amount before the industrial revolution by the end of the 21st Century, then the CO2 level at present has to reduce to more than half of the present value. In Taiwan, because of the industrial development, the energy requirement increased rapidly resulting in the rapid yearly increase in CO2 emission. The changes in mangrove ecology are early indicators of climatic changes. The influence of these changes on the global distribution of mangrove and regional ecological system is one of the topics that draw the attention of government of several countries and environmental protection organizarion. The ecological system of mangrove is a multi-purpose system, which could be used to generate high yielding, and sustainable natural products. Recently, the destruction caused by land development or public works resulted in rapid decrease in the area of mangrove in different countries around the world. Taiwan is surrounded by the ocean, the effective utilization of the wetlands along the coastal region by means of mangrove restoration and forestation can reduce the emission of green house gases such as CO2 and methane (CH4). In order to make the Kyoto Treaty effective, investment in the reduction of CO2 emission is an alternative to those industrial enterprises in the countries where the area of forestation is reducing.
In reality, the Avicennia marina mangrove area along the coast of Pingtung is in the form of stripe-shaped community which is different from regions where the mangrove appeared as group communities in the estuaries. The present research utilized images from three sources: SPOT satellite, Formosat-2 satellite and airborne remote sensing. Application of ERDAS and ArcGIS software in combination with the Supervised Classification and Maximum Likelihood Method was utilized to study the land cover classification to evaluate a suitable way for remote sensing. Furthermore it was attempted to predict the carbon sequestration of Avicennia marina mangrove in Pingtung area using airborne remote sensing method to investigate the Normalized Difference Vegetative Index (NDVI) of the mangrove.
Results of the present study indicated that SPOT satellite images and the un-supplemented near red (NIR) spectrum of Formosat-2 satellite images were not suitable to monitor remote sensing of the mangrove area in Pingtung because the sensing resolution was greater than the width of the mangrove growing stripe. Only the airborne remote sensing with high resolution and with near red spectrum images was suitable for this purpose. According to the airborne remote sensing, the NDVI values of the mangroves in Pingtung area were between 0.226 to 0.283 and the estimated total amount of carbon sequestration was 1,491.74 tons. The present research only discussed the feasibility of using remote sensing to estimate the total amount of carbon sequestration. During this study, the traditional ground investigation of biomass for carbon sequestration of mangroves was not included as the check for comparison. Through the literatures’ survey of mangrove remote sensing, the NDVI values of other mangrove species are within the range of 0.20 to 0.465, indicating the result of the present study is feasible.

並列關鍵字

Mangrove ； Avicennia marina ； Remote Sensing ； Carbon Sequestration

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