scholarly journals Mapeamento e identificação de vetores responsáveis pela supressão do manguezal na Zona Costeira do Baixo Sul da Bahia, Brasil (Mapping and identification of vectors responsible for mangrove suppression in the Southern Bahia Lowlands, Brazil)

2020 ◽  
Vol 12 (7) ◽  
pp. 2503
Author(s):  
Ana Paula Sena de Souza ◽  
Ivonice Sena de Souza ◽  
George Olavo ◽  
Jocimara Souza Britto Lobão ◽  
Rafael Vinícius de São José

O ecossistema manguezal representa 8% de toda a linha de costa do planeta ocupando uma área total de 181.077 km2. O Brasil é o segundo país em extensão de áreas de manguezal, ficando atrás apenas da Indonésia. O objetivo do presente estudo foi mapear e identificar os principais vetores responsáveis pela supressão da cobertura das áreas de manguezal na região do Baixo Sul da Bahia, Brasil, a partir de imagens de satélite Landsat disponíveis para o período entre 1994 e 2017. Os mapeamentos foram realizados a partir de classificação supervisionada, utilizando o método Maxver. A acurácia da classificação obtida foi verificada através da verdade de campo, de índices de Exatidão Global, e dos coeficientes de concordância kappa e Tau. As classes que apresentaram maior área de cobertura no período analisado foram: vegetação ombrófila densa, agropecuária, solo exposto e manguezal. Foram identificados dois vetores principais responsáveis pela supressão dos bosques de mangue: a expansão desordenada das áreas urbanas (com destaque para o município de Valença) e o avanço da atividade de carcinicultura clandestina, devido a instalação de tanques de cultivo de camarão sem o devido processo de licenciamento ambiental (sobretudo no município de Nilo Peçanha). O uso das geotecnologias, em especial o Sensoriamento Remoto e os Sistemas de Informações Geográficas, foram ferramentas fundamentais na identificação destes vetores responsáveis pela supressão das áreas de manguezal na área de estudo região do Baixo Sul da Bahia.  Mapping and identification of vectors responsible for mangrove suppression in the Southern Bahia Lowlands, BrazilA B S T R A C TThe mangrove ecosystem represents 8% of the entire coastline of the planet and occupies a total area of 181,077 km2. Brazil is the second largest country in terms of mangrove areas, second only to Indonesia. The aim of the present study was to map and identify the main vectors responsible for the suppression of mangrove cover in the Southern Lowlands of Bahia, Brazil, from Landsat satellite images available for the period 1994-2017. based on supervised classification using the Maxver method. The accuracy of the classification obtained was verified through field truth, Global Accuracy indices, and kappa and Tau agreement coefficients. The classes that presented larger coverage area in the analyzed period were: dense ombrophilous vegetation, agriculture, exposed soil and mangrove. Two main vectors responsible for the suppression of mangrove forests were identified: the disorderly expansion of urban areas (especially the municipality of Valença) and the advance of clandestine shrimp farming due to the installation of shrimp farms without due environmental licensing process (mainly in the municipality of Nilo Peçanha). The use of geotechnologies, especially Remote Sensing and Geographic Information Systems, were fundamental tools in the identification of these vectors responsible for the suppression of mangrove areas in the study area of the Southern Bahia Lowlands.Key-words: environmental impacts, satellite image, shrimp farming.

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Komang Iwan Suniada

Study of the function of mangrove forests as a sediment trap has been largely undertaken using field measurement methods, but only a few researches that fully utilize remote sensing data to find out the influence of mangrove forest’s area changes against the Total Suspended Matter (TSM) making this study very interesting and important to do.  This research was conducted in Perancak estuary area which is one of mangrove ecosystem area in Bali besides West Bali National Park, Benoa Forest Park and Nusa Lembongan. The data used to generate TSM information and change of mangrove forest area in this research is medium resolution satellite image data, Landsat.  Tidal data and rainfall data were used as a supporting data. The information of TSM concentration obtained by using Budhiman (2004) algorithm, shows that along with the increasing of mangrove forest area has caused the decreasing of TSM concentration at mouth Perancak river. The decline was caused by sediments trapped and settled around trees or mangrove roots, especially the Rhizophora mangroves. In addition to the increasing of mangrove forest area, the tidal oceanography factor also greatly influences the TSM fluctuation around Perancak river mouth. 


2021 ◽  
Vol 36 (3) ◽  
pp. 255-271
Author(s):  
Tito Aditya Perdana ◽  
Febrianur Ibnu Fitroh Sukono Putra ◽  
Risanda Alirastra Budiantoro

Introduction/Main Objectives: This study estimates how much economic value will be lost from contact activities within the coastal areas in the research location. Background Problems: The area of Semarang City has flood and tidal problems, the damage to the mangrove forests in Semarang City began with the boom in shrimp farming between 1980 and 1990. Hopefully, this valuation can provide an overview of the current health of the ecosystem and become the basis for a mangrove management strategy in the future. Novelty: The novelty of this study is that it uses a sharper satellite (Image Pleades Resolution 0.5 m) to calculate the mangrove area in the research location. Research Methods: This research uses a total economic valuation, an estimation of the mangrove’s carbon stock and heavy metals, the replacement cost to prevent tidal flooding, and the willingness to pay. Findings/Results: We find that the existing economic value in the study area is very large and should be preserved for conservation. Conclusion: The environment cannot produce something instantly, but it needs to be preserved as a balance to nature.


2012 ◽  
Vol 13 (1) ◽  
pp. 19 ◽  
Author(s):  
Halda Aditya Belgaman ◽  
Sri Lestari ◽  
Hilda Lestiana

Pulau panas adalah suatu fenomena dimana suhu udara di suatu daerah lebih tinggi daripada suhu udara terbuka di sekitarnya. Daerah urban (perkotaan) sering mempunyai suhu lebih tinggi 1-6 derajat Celsius dibandingkan daerah sekitarnya (daerah pinggiran/ rural). Fenomena inilah yang dikenal sebagai ”Pulau Panas perkotaan” atau ”Urban Heat Island” (UHI). Penelitian ini bertujuan untuk mengetahui pengaruh fenomena pulau panas perkotaan terhadap parameter iklim terutama suhu dan curah hujan di daerahJakarta dan sekitarnya. Data yang digunakan pada tugas akhir ini adalah data curah hujan dan temperatur udara harian pada 5 stasiun pengamatan iklim, periode Januari 1991 – Desember 2001 sebagai data permukaan. Citra satelit Landsat 7 ETM+ path / row 122/064 akuisisi tanggal 15/07/2001 band 5,4,2 digunakan untuk menganalisis tutupan lahan dan band 6 digunakan untuk distribusi temperatur permukaan. Hasil menunjukkan nilai temperatur permukaan Kota Jakarta dan sekitarnya berada antara 15.07˚C hingga 33.28˚C. Lokasi pulau panas perkotaan terdapat di daerah Jakarta pusat dan Jakarta utara, dengan perbedaan temperatur sebesar 3˚C dibandingkan dengan daerah sekitarnya.Tutupan lahan yang terdapat di lokasi tersebut merupakan lahan terbangun yang terdiri dari bangunan perumahan, perkantoran, dan jalan raya. Perhitungan nilai korelasi Spearman antara data temperatur udara dari lima stasiun pengamatan dengan nilai piksel temperatur permukaan memperlihatkan adanya korelasi positif antara dua variabel tersebut yang ditunjukkan oleh indeks korelasi sebesar 0.6.Dengan persamaan regresi diperoleh citra temperatur permukaan di seluruh daerah pengamatan yang hasilnya menggambarkan bahwa lokasi pulau panas perkotaan sangat berpengaruh terhadap distribusi temperatur udara di atasnya.Heat island was a phenomenon where the temperature of air in one region higher than the temperature of the open air around it. Urban areas often had the temperature higher 1-6 Celsius when compared the area of surrounding area (the area of outskirts/rural). This phenomenon that was known as ”Pulau Panas Perkotaan” or ”Urban Heat Island” (UHI). This Research aimed to knowing influence of the heat islands of urban areas to climate parameter especially the temperature and the rainfall in the Jakarta and surrounding area. Data used in this research was rainfall data and daily air temperaturefrom 5 climate observation stations, within time period from January 1991 to December 2001 as the surface data. The Landsat satellite image 7 ETM+ path/row 122/064 acquisition date 15/07/2001, band 5, 4, 2 was used to analyze the cover of land and the band 6 was used for the distribution of surface temperature was based on the pixels value.Results showed the value of surface temperature in Jakarta and surrounding area was between 15.07˚C through to 33.28˚C. Location of heat island were in the centre Jakarta and north Jakarta, with the difference of the temperature as big as 3˚C with thesurrounding area. The land cover in this location were the housing building, the office complex, and the highway. Calculation of Spearman correlation value between the air temperature and surface temperature showed the existence of the positive correlation between two variables that it was demonstrated by the correlation index 0.6. From the regression equation we get the interpolated air temperature in Jakarta area.


Jurnal Segara ◽  
2019 ◽  
Vol 15 (2) ◽  
Author(s):  
Yulius Yulius ◽  
Syahrial Nur Amri ◽  
August Daulat ◽  
Sari Indriani Putri

Mangrove forests are tropical coastal vegetation communities, which has the ability to grow in coastal area with tidal and muddy environment. Several functions of mangrove forest such as ecological functions can be used for coastal protection, trapping sediment and strengthen the coastal ecosystems. Coastal waters in Dompu Regency, West Nusa Tenggara have natural mangrove ecosystem with a huge potency and advantages to the region. This study aimed to understand the condition of mangrove ecosystem based on satellite image analysis of Landsat 8 Operational Land Imager (OLI) in 2014 and assess the potency, information related to the utilization by community. Data collection in this study were combined from satellite imagery interpretation with interview and questionnaires. The results showed that the mangrove forest extent in Dompu Regency Coastal Waters were about 90,631 ha with uniformity index 0.68 (medium uniformity). Two mangrove species were found in the region namely Rhizopora stylosa and Rhizopora apiculata and used by the community for several purposes such as firewood, natural coastal protection from tidal, waves and abrasion, also for crabs and fish spawning ground.


2018 ◽  
Vol 2017 (2) ◽  
Author(s):  
Dian N Handiani ◽  
Soni Darmawan ◽  
Rika Hernawati ◽  
Muhammad F Suryahadi ◽  
Yohanes D Aditya

ABSTRAKPenelitian ini adalah kajian awal dari valuasi ekonomi atas manfaat dan jasa ekosistem di pesisir Subang. Faktor-faktor utama dalam valuasi adalah keberadaan ekosistem dan perubahan di pesisir, serta manfaat dan jasa ekosistemnya. Estimasi perubahan garis pantai dihitung berdasarkan tumpang susun data satelit Landsat tahun 1988, 1996, 2003, dan 2016. Estimasi menunjukkan terjadi perubahan garis pantai sebesar 8,17 km sejak tahun 1988-2013. Perubahan tersebut didominasi oleh sedimentasi dan abrasi sepanjang pantai. Sedimentasi tertinggi terjadi di Kecamatan Pusakanagara (869,9 ha) dan Blanakan (725,4 ha), serta abrasi tertinggi terjadi di Kecamatan Legonkulon (885,8 ha). Ekosistem alami yang berubah dan dimanfaatkan secara intensif di pesisir Subang adalah kawasan estuari dan mangrove. Sehingga mengakibatkan penurunan fungsi ekologi pada ekosistem tersebut. Adapun lahan tambak sebagai ekosistem buatan yang menggantikan kawasan mangrove, hanya berfungsi sebagai penyedia kebutuhan pangan. Penelitian ini menunjukkan perlunya valuasi ekonomi atas lahan mangrove versus budidaya tambak di Kecamatan Legonkulon, serta kawasan estuari yang berfungsi sebagai sarana transportasi di Kecamatan Pusakanagara.Kata kunci: garis pantai, ekosistem pesisir, erosi, sedimentasi, SubangABSTRACTThis research is a preliminary study for economic valuation of coastal services and goods in Subang Regency. Main factors in the valuation are ecological existing, changing, services and goods of coastal ecosystem. Coastline changes estimation was based on the overlay of Landsat satellite image at year of 1988, 1996, 2003, and 2016. Estimation shows since year of 1988 to 2013 there is changing of coastline around 8,17 km. The changes are dominantly caused by coastline sedimentation and abrasion. Higher sedimentation occured in Pusakanagara (869,9 ha) and Blanakan (725,4) Subdistrict, while highest abrasion occured in Legonkulon (885,8 ha) Subdistrict. Estuary and mangrove forests are natural ecosystem that had been used intensively and changing very excessively in this region. These changing causes degradation in functions of these ecosystems. Meanwhile, changing of mangrove forest into aquaculture only provides food. This research shows the necessity in economic valution of mangrove forest versus aquaculture in Legonkulon Subdistrict, and also estuary as transportation function in Pusakanagara Subdistrict.Keywords: coastline, coastal ecosystem, erosion, sedimentation, Subang


2021 ◽  
Vol 10 (1) ◽  
pp. 55-63
Author(s):  
Alin Maulani ◽  
Nur Taufiq-SPJ ◽  
Ibnu Pratikto

Kecamatan Muara Gembong adalah wilayah dengan ekosistem mangrove yang cukup luas dan tersebar. Mangrove adalah kelompok jenis tumbuhan yang tumbuh di sepanjang garis pantai tropis sampai subtropis di suatu lingkungan yang mengandung garam dan bentuk lahan berupa pantai dengan reaksi tanah anaerob. Kondisi ekosistem mangrove sangat peka terhadap gangguan dari luar terutama dari kegiatan pencemaran, konversi hutan mangrove menjadi kawasan non-hutan, ekploitasi hasil mangrove yang berlebihan sehingga terjadi dinamika pada luasan lahannya. Perubahan yang terjadi pada ekosistem mangrove ini dapat berupa penambahan, pengurangan, dan lahan yang tetap. Metode yang dilakukan pada penelitian ini berupa pengolahan data satelit citra Sentinel 2A, Landsat 8, dan Landsat 5 untuk menganalisa sebaran mangrove pada tahun 2009, 2014, dan 2019, serta perubahan yang terjadi. Validasi data dilakukan dengan pengamatan kawasan langsung di lokasi penelitian berdasarkan pengolahan data yang telah dilakukan. Hasil pengolahan data menunjukan di Kecamatan Muara Gembong pada tahun 2009-2019 diketahui terjadi penambahan luasan lahan mangrove sebesar 1017,746 ha dan pengurangan luasan mangrove sebesar 275,37 ha. Selain itu, terdapat pula lahan mangrove yang tetap bertahan pada kurun waktu 2009-2019 seluas 255,057 ha. Sehingga perubahan lahan mangrove yang terjadi di Kecamatan Muara Gembong cenderung mengalami pertambahan luasan lahan mangrove, yaitu sebesar 66% lahan mangrove yang bertambah. Muara Gembong Subdistrict is an area with a wide and scattered mangrove ecosystem. Mangroves are a group of plant species that grow along tropical to subtropical coastlines in an environment that contains salt and landforms in the form of beaches with anaerobic soil reactions. The condition of mangrove ecosystems is very sensitive to outside disturbances, especially from pollution activities, conversion of mangrove forests to non-forest areas, excessive exploitation of mangrove products resulting in dynamics in the area of land. Changes that occur in this mangrove ecosystem can be in the form of addition, subtraction, and permanent land. The method used in this research is the processing of Sentinel 2A, Landsat 8, and Landsat 5 satellite image data to analyze the distribution of mangroves in 2009, 2014 and 2019, and the changes that occur. Data validation is done by direct observation of the area at the research location based on data processing that has been done. The results of data processing showed that in Muara Gembong Subdistrict in 2009-2019 it was known that there was an increase in the area of mangrove land by 1017, 746 ha and reduction in mangrove area by 275.37 ha. In addition, there are also mangrove lands that have survived in the period 2009-2019 covering 255,057 ha. So that changes in mangrove land that occur in Muara Gembong District tend to experience an increase in the area of mangrove land, which is equal to 66% of the mangrove land that is increasing.


2019 ◽  
Vol 8 (1) ◽  
pp. 27-35
Author(s):  
Amin Yunita Nur Annisa ◽  
Rudhi Pribadi ◽  
Ibnu Pratikto

Mangrove merupakan ekosistem daerah peralihan yang memiliki beberapa fungsi diantaranya ekologis, fisik maupun ekonomi. Kerusakan mangrove sering terjadi di beberapa daerah sehingga kelestarian mangrove sangat perlu dijaga. Salah satu upaya untuk mengurangi kerusakan tersebut dengan kegiatan rehabilitasi. Kegiatan rehabilitasi ini bertujuan untuk memulihkan kondisi mangrove seperti keadaan semula. Keberhasilan dari kegiatan rehabilitasi ini dapat dipantau dengan sistem penginderaan jauh menggunakan citra Satelit Landsat. Penelitian ini dilakukan pada bulan Juni- Juli 2018. Metode penelitian ini menggunakan metode deskriptif bersifat eksploratif. Materi dalam penelitian ini adalah data citra satelit Landsat 5 untuk tahun 2008 dan Landsat 8 untuk tahun 2018. Berdasarkan hasil penelitian didapatkan nilai perubahan luasan hutan mangrove di Desa Kaliwlingi, Kecamatan Brebes dan Desa Sawojajar, Kecamatan Wanasari tahun 2008, 2013 dan 2018. Luas mangrove di Desa Kaliwlingi Kecamatan Brebes pada tahun 2008-2013 bertambah sebesar 101,25 ha yaitu 48,42 ha pada tahun 2008 dan 149,67 ha pada tahun 2013. Pada tahun 2013-2018 juga bertambah 184,23 ha yakni 333,9 ha pada tahun 2018. Pada Desa Sawojajar Kecamatan Wanasari, luas mangrove juga bertambah sebesar 0,09 ha yakni 24,39 ha pada tahun 2008 bertambah menjadi 24,48 ha pada tahun 2013. Tahun 2013-2018 juga bertambah sebesar 12,24 ha sehingga menjadi 36,72 ha di tahun 2018. Luas mangrove di Desa Kaliwlingi dan Sawojajar bertambah dalam kurun waktu sepuluh tahun.] Mangroves are transitional ecosystems that have several functions including ecological, physical and economic. Mangrove damage often occurs in several areas so that the preservation of mangroves is very important. One effort to reduce this damage is through rehabilitation activities. This rehabilitation activity aims to restore the condition of mangroves as they were before. The success of these rehabilitation activities can be monitored by remote sensing systems using Landsat Satellite imagery. This research was conducted in June-July 2018. This research method uses descriptive methods that are alternative. The material in this study is Landsat 5 satellite image data for 2008 and Landsat 8 for 2018. Based on the results of the study, the value of changes in a mangrove forests in Kaliwlingi Village, Brebes and Sawojajar Villages, Wanasari District in 2008, 2013 and 2018. The area of mangroves in Kaliwlingi Village, Brebes Subdistrict in 2008-2013 it increased by 101.25 ha, which was 48.42 ha in 2008 and 149.67 ha in 2013. In 2013-2018 it also increased by 184.23 ha, namely 333.9 ha in 2018. In Sawojajar Village, Wanasari Subdistrict, the area of mangroves also increased by 0.09 ha, which was 24.39 ha in 2008 which increased to 24.48 ha in 2013. 2013-2018 also increased by 12.24 ha to 36.72 ha in 2018. The area of mangrove in Kaliwlingi and Sawojajar villages has increased in ten years.


2019 ◽  
Vol 5 ◽  
pp. 104
Author(s):  
Suhendra Purnawan ◽  
Subari Yanto ◽  
Ernawati S.Kaseng

This study aims to describe the profile of vegetation diversity in the mangrove ecosystem in Tamuku Village, Bone-Bone-Bone District, North Luwu Regency. This research is a qualitative research using survey methods. The data collection technique uses the Quadrant Line Transect Survey technique. The data analysis technique uses the thinking flow which is divided into three stages, namely describing phenomena, classifying them, and seeing how the concepts that emerge are related to each other. The results of this study are the profile of mangrove vegetation in Tamuku Village, which is still found 16 varieties of true mangrove vegetation and 7 varieties of mangrove vegetation joined in the coastal area of Tamuku Village, Bone-Bone District, North Luwu Regency, South Sulawesi. The condition of mangrove vegetation in Tamuku Village is currently very worrying due to human activities that cause damage such as the project of normalization of flow, opening of new farms, disposal of garbage, water pollution due to chemicals, and exploitation of mangrove forests for living needs. The impact is ecosystem damage and reduced vegetation area as a place to grow and develop mangroves.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Francesco Maria Sabatini ◽  
Hendrik Bluhm ◽  
Zoltan Kun ◽  
Dmitry Aksenov ◽  
José A. Atauri ◽  
...  

AbstractPrimary forests, defined here as forests where the signs of human impacts, if any, are strongly blurred due to decades without forest management, are scarce in Europe and continue to disappear. Despite these losses, we know little about where these forests occur. Here, we present a comprehensive geodatabase and map of Europe’s known primary forests. Our geodatabase harmonizes 48 different, mostly field-based datasets of primary forests, and contains 18,411 individual patches (41.1 Mha) spread across 33 countries. When available, we provide information on each patch (name, location, naturalness, extent and dominant tree species) and the surrounding landscape (biogeographical regions, protection status, potential natural vegetation, current forest extent). Using Landsat satellite-image time series (1985–2018) we checked each patch for possible disturbance events since primary forests were identified, resulting in 94% of patches free of significant disturbances in the last 30 years. Although knowledge gaps remain, ours is the most comprehensive dataset on primary forests in Europe, and will be useful for ecological studies, and conservation planning to safeguard these unique forests.


Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 637
Author(s):  
Huong Thi Thuy Nguyen ◽  
Giles E. S. Hardy ◽  
Tuat Van Le ◽  
Huy Quoc Nguyen ◽  
Hoang Huy Nguyen ◽  
...  

Mangrove forests can ameliorate the impacts of typhoons and storms, but their extent is threatened by coastal development. The northern coast of Vietnam is especially vulnerable as typhoons frequently hit it during the monsoon season. However, temporal change information in mangrove cover distribution in this region is incomplete. Therefore, this study was undertaken to detect change in the spatial distribution of mangroves in Thanh Hoa and Nghe An provinces and identify reasons for the cover change. Landsat satellite images from 1973 to 2020 were analyzed using the NDVI method combined with visual interpretation to detect mangrove area change. Six LULC classes were categorized: mangrove forest, other forests, aquaculture, other land use, mudflat, and water. The mangrove cover in Nghe An province was estimated to be 66.5 ha in 1973 and increased to 323.0 ha in 2020. Mangrove cover in Thanh Hoa province was 366.1 ha in 1973, decreased to 61.7 ha in 1995, and rose to 791.1 ha in 2020. Aquaculture was the main reason for the loss of mangroves in both provinces. Overall, the percentage of mangrove loss from aquaculture was 42.5% for Nghe An province and 60.1% for Thanh Hoa province. Mangrove restoration efforts have contributed significantly to mangrove cover, with more than 1300 ha being planted by 2020. This study reveals that improving mangrove restoration success remains a challenge for these provinces, and further refinement of engineering techniques is needed to improve restoration outcomes.


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