파나마 Parita Bay에서 32 년간의 맹그로브 숲 토지 피복 변화

학위논문(석사)--서울대학교 대학원 :농업생명과학대학 산림과학부(산림환경학전공),2019. 8. Kim, Hyun Seok.Mangroves forests around the world have been experiencing a drastic loss. This decrease is attributed in part to changes in bio-climatic factors (e.g. rainfall, temperature, tidal range, extreme events, etc.) and to anthropogenic activities such as coastal development, agriculture, timber extraction, upstream discharge of contaminants, as well as aquaculture and saltpan construction. Whereas remote sensing tools have contributed to detect mangrove vulnerable areas in order to respond with appropriate conservation policies. The principal aims of our study are to quantify the changes in mangrove cover and to identify possible drivers of its change. We present the first mangrove land cover-change analysis in Panama using satellite imagery after the year 2000, and the first in Parita Bay. Mangrove cover changes were determined using Landsat satellite images in four (4) points of time: 1987, 1998, 2009 and 2019, which consequently, were subdivided into three (3) period of study. A supervised classification was employed to quantify changes in areas of different land use-cover types; and the NDVI (Normalized Difference Vegetation Index) was determined for each image, in order to observe changes of greenness in mangrove canopy cover. Our study revealed mangrove area in Parita Bay has increased by 4.7% during the last 32 years and seems to have a good health status reflected in the presence of high NDVI values. However, there was a 1.26% decline of mangrove cover at the first period (1987 to 1998), principally related to the conversion into other types of vegetation and bare soil. During the same period, results also revealed a high expansion of aquaculture and saltpan by 95.88%, and a decline of ~40% in high and very high-density NDVI (>0.46). After the initial decrease of mangrove area, it increased 6% of its extent for the last two decades, and the annual increment rate was even greater for the last decade (0.43%). The increase of mangroves in Parita Bay was mostly due to the conversion from water, other vegetation and bare soil classes. This leads to assume that natural regeneration characteristics coupled with restoration projects developed in the region may had a positive influence over the mangrove cover. In addition, mangroves in protected areas declined at an annual rate of 0.11%, while the unprotected mangroves increased at 0.50% per year during the last period (2009-2019). Our study suggests continuous management of mangrove forests is essential for the areas where the ecosystem vulnerability is high.세계의 맹그로브 숲은 대폭적인 손실을 경험했다. 이러한 감소는 생물-기후 인자 (예 : 강우, 기온, 조수 범위, 극한 현상 등)의 변화와 연안 개발, 농업, 목재 채취, 오염 물질의 상류 배출과 같은 인위적 활동뿐만 아니라 양식 및 소금염전 건설이 원인이다. 원격 탐사 도구가 적절한 보존 정책에 응답하기 위해 맹그로브 취약 지역을 탐지하는데 기여한다. 본 연구의 주요 목적은 맹그로브 피복의 변화를 정량화하고 변화의 가능한 구동인자를 규명하는 것이다. 우리는 2000 년 이후의 위성 이미지와 Parita Bay의 첫 번째 연구에서의 위성 이미지를 사용하여 파나마에서 맹그로브 토지 피복 변화의 첫 번째 분석을 제시한다. 맹그로브 커버 변경은 1987 년, 1998 년, 2019 년의 네 가지 시점에서 Landsat 인공위성 이미지를 사용하여 결정되었으며, 결과적으로 세 번의 연구 기간으로 세분되었다. 감독 된 분류는 다른 토지 이용 표지 유형의 영역에서의 변화를 정량화하기 위해 사용되었다. 맹그로브 캐노피 덮개의 녹색 변화를 관찰하기 위해 각 이미지에 대해 NDVI (Normalized Difference Vegetation Index)를 결정했다. 우리의 연구에 따르면 Parita Bay의 맹그로브 지역은 지난 32 년 동안 4.7 % 증가했으며 높은 NDVI 수치가 존재할 때 건강 상태가 양호한 것으로 나타났다. 그러나 첫 번째 기간 (1987 ~ 1998)에는 맹그로브 피복이 1.26 % 감소했으며, 주로 '다른 종류의 식물'과 '맨땅 토양'으로의 전환과 관련이있다. 같은 기간 동안 결과는 또한 95.88 %의 높은 양식 및 소금물 팽창과 높은 고밀도 NDVI (> 0.46)에서 약 40 %의 감소를 나타났다. 맹그로브 지역의 초기 감소 이후 지난 20 년간 6 %의 증가율을 보였으며 지난 10 년간 0.43 %의 증가율을 보였다. Parita Bay의 맹그로브 (mangroves) 증가는 주로 '물', '다른 식물'및 '맨손 토양'등으로 인한 것이 었다. 이것은 지역에서 개발 된 복원 프로젝트와 결합 된 자연 재생 특성이 맹그로브 피복에 긍정적 영향을 줄 수 있다고 가정한다. 또한, 보호 지역의 맹그로브는 연간 비율로 0.11 %로 감소했으며, 보호받지 못한 맹그로브는 지난 기간 (2009-2019) 동안 매년 0.50 %로 증가했다. 우리 연구는 생태계 취약성이 높은 지역에서 맹그로브 숲의 지속적인 관리가 필수적임을 시사한다.I. Introduction 1 II. Material and Methods 5 1. Study Area 5 2. Data Selection and Image preprocessing 6 3. Image Classification 7 4. Field Ground Truth and Accuracy Assessment 10 5. NDVI Analysis 11 6. Land Cover-Use Change (LUCC) detection 12 7. Analysis in Protected Areas 13 8. Analysis of Environmental variables in the study area 13 III. Results 16 1. Classification Accuracy 16 2. Land Use-Cover Change (LUCC) Detection and mangrove estimation in Parita Bay 18 3. NDVI Classes Changes on time 23 5. Mangroves changes in Protected vs. Unprotected Area 28 6. Local Climatic Variables Analysis 33 6.1 Rainfall 33 6.2 Temperature 34 IV. Conclusion 42 References 44 Web References 50 Appendix A 52 Appendix B 54 Appendix C 55 Appendix D 56 Abstract (in Korean) 57 Acknowledgments 59Maste

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