scholarly journals ANALISIS HABITAT DAN PERUBAHAN LUASAN TERUMBU KARANG DI PULAU MENJANGAN BESAR, KEPULAUAN KARIMUNJAWA MENGGUNAKAN CITRA SATELIT

2016 ◽  
Vol 5 (4) ◽  
pp. 302-310
Author(s):  
Rio Januardi ◽  
Agus Hartoko ◽  
Pujiono Wahyu Purnomo
Keyword(s):  
Remote Sensing ◽  
Coral Reef ◽  
Coral Reefs ◽  
Good Condition ◽  
Landsat 8 ◽  
Geometric Center ◽  
Sensing Technology ◽  
Coral Reef Area ◽  
Short Time ◽  
Line Intercept

ABSTRAK Perairan Indonesia menyimpan keanekaragaman hayati laut karang tertinggi, diperkirakan luas ekosistem terumbu karang Indonesia mencapai 50.000 km2 yaitu 25 persen dari luas terumbu karang dunia. Penggunaan teknologi penginderaan jauh merupakan salah satu alternatif yang tepat untuk mendeteksi terumbu karang bagi negara yang mempunyai wilayah yang sangat luas dan memerlukan waktu yang relatif singkat serta biaya murah. Penelitian ini bertujuan untuk mengetahui jenis, kondisi, perubahan luasan dan tingkat akurasi monitoring terumbu karang di Pulau Menjangan Besar menggunakan citra satelit Landsat 8. Penelitian dilaksanakan pada November 2015-Januari 2016 di Pulau Menjangan Besar dan di Laboratorium Marine Geometric Center, Jurusan Perikanan UNDIP. Metode penelitian yang digunakan yaitu metode eksploratif untuk mengetahui jenis dan kondisi terumbu karang menggunakan metode Line Intersept Transect dan metode koreksi kolom air atau Lyzenga. Hasil penelitian  menemukan kondisi terumbu karang di Pulau Menjangan Besar masih dalam kondisi baik dengan persentase penutupan karang sebesar 51,6 persen. Jenis terumbu karang yang terdapat di Pulau Menjangan Besar yaitu Acropora sp, Stylopora sp, Porites sp, Favia sp, Heliopora sp, Euphylia sp, Pocilopora sp, Goniopora sp dan Favites sp dengan nilai keaneragaman sebesar 1.28 tergolong sedang/moderat dan nilai dominasi sebesar 0.58. Terumbu karang mengalami penurunan luasan sebesar 7,92 Ha dari tahun 2013-2015. Tingkat akurasi penggunaan citra satelit Landsat 8 yaitu 81,25 persen. Kata kunci :Persentase penutupan karang; Luasan habitat; Menjangan Besar; Penginderaan jauh ABSTRACTThe ocean of Indonesia has the highest biodiversity of Coral Reef, the extent of Indonesian’s coral reefs widely predicted 50.000 km2 which is about 25% of the world’s. The use of remote sensing technology is one the alternatives that is appropriate for the detection of coral reefs for a country that has a very wide area and requires a relatively short time and reasonable cost. This study aimed to determine the type; condition; changes in the area; and the level of monitoring coral reefs accuracy in Menjangan Besar Island used Landsat 8 satellite. The study was conducted on November 2015 until January 2016 in Menjangan Besar Island and the Marine Geometric Center, Fisheries Department at Diponegoro University. This research uses an explorative method to determine the type and condition of coral reefs using line intercept transect method and correction on water column method or Lyzenga. The result of this research is the condition of coral reefs in Menjangan Besar in the good condition with the cover percentage of coral at 51.6%. The species of Coral reefs in Menjangan Besar are identified as Acropora sp, Stylopora sp, Porites sp, Favia sp, Heliopora sp, Euphylia sp, Pocilopora sp, Goniopora sp and Favites sp with the value of diversity about 1.28 classified as moderate and the value of dominance of 0.58. The coral reef area decreased by 7.92 ha of the year 2013 to 2015. The accuracy level used Landsat 8 imagery satellite is 81.25%. This level of accuracy using Landsat 8 satellite imagery is 81.25%. Keywords :Percentages of coral reef cover; Extents habitat; Menjangan Besar; Remote sensing.

scholarly journals Coral reef monitoring in Panjang Island, Central Bangka

2021 ◽  
Vol 926 (1) ◽  
pp. 012099
Author(s):  
W Adi ◽  
I Akhrianti ◽  
M Hudatwi
Keyword(s):  
Remote Sensing ◽  
Coral Reef ◽  
Coral Reefs ◽  
Satellite Imagery ◽  
Good Condition ◽  
Aerial Photographs ◽  
Visual Interpretation ◽  
Composite Band ◽  
Sentinel 2A ◽  
Color Composite

Abstract Bangka Island is the largest tin producer in Indonesia and since the granting of tin mining freedom in 2000, unconventional tin mining (TI) is increasingly prevalent. The existence of mining activities will directly or indirectly damage the environment both on land and at sea. Especially the high biodiversity of coral reef ecosystem. The purpose of this research was to analyze a map of the distribution of coral reef based on Sentinel 2A satellite imagery data. Analyze the extent of the coral reefs in shallow waters of Putri Island, and analyze of the condition coral reefs (percentage cover, mortality index and genus diversity) with using collaboration betwen the coral diving data and remote sensing data. Studies of changes in coral reef ecosystems have been ongoing since several decades ago. The combination of satellite imagery and aerial photographs is capable of making long-term and continuous observations on mapping and change detection. Remote sensing technology has several advantages overconventional sampling to monitor a large area in time almost simultaneously and continuously including the difficult to explore areas. This research was conducted with visual interpretation by using standard true color composite band (483) and false color composite band (843) of Sentinel 2A and also using lyzenga transformation. Estimation of coral reefs area based on result is 475,96 ha (2016) and decreased to 475 ha (2021). The condition of coral reefs at the research location is a good condition.

scholarly journals Kondisi Terumbu Karang Di Pantai Empu Rancak Kabupaten Jepara

2018 ◽  
Vol 21 (1) ◽  
pp. 49 ◽  
Author(s):  
Suryono Suryono ◽  
Edi Wibowo ◽  
Raden Ario ◽  
Nur Taufiq SPJ ◽  
Ria Azizah
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Coastal Waters ◽  
Coral Cover ◽  
Good Condition ◽  
Ecological Impacts ◽  
Marine Tourism ◽  
Run Off ◽  
Index Value ◽  
Line Intercept

Abstract Coral Reef Condition In Coastal Waters of Empu Rancak, Mlonggo, Regency of Jepara Empu Rancak coastal  waters in Karanggondang village, Mlonggo District is one of the coral reef ecosystem location in coastal area of  Jepara Regency. Following the growth of culinary and Marine  tourism bring the need for monitoring the condition of coral reefs so that such activity does not provide ecological impacts against the condition of coral reefs. The method used to assess the condition of coral reefs  is Line Intercept Transect which done by percentage calculation of living coral coverage. The research results shows that the condition of the coral reefs in a depth of 3 metres found coral cover percentage of 4.5%, while at a depth of 6 meters found coral cover percentage of 9.7%. From this result indicates the coral reefs in critical condition，however the high biodiversity and dominance index value is presumed that these coral reefs was in good condition. It`s showed by the high percentage of coral die either at a depth of 3 metres (95.54%) or at a depth of 6 meters(90.30%). The diversity of species of coral were found at a depth of 3 meters consist of 6 genus, they are: Goniastrea sp., Favia sp., Galaxea sp., Porites, Acropora sp. and Montipora sp., whereas at a depth of 6 meters were found more species of coral diversity for at least 11 genus, they are: Acropora sp., Favites sp., Echinopora sp., Goniastrea sp. Symphyllia agaricia sp, Favia sp., Goniopora sp., Porites sp., Montipora sp., Platygyra sp., and Montastrea sp. The condition of coral reefs cover which relatively critical are caused by decreasing the quality of waters ecology that caused by sedimentation rate and runoff processes of land activity, high waves in northwest monsoon and the growth of culinary tourism as well as marine  tourism in Empu Rancak coastal  waters gradually worsen the condition of coral reefs. Keywords : Coral reef, tourism, Line Intercept Transect, AbstrakPerairan pantai Empu Rancak desa Karanggondang, Kecamatan Mlonggo merupakan salah satu lokasi ekosistem  terumbu karang yang berada pesisir di kabupaten Jepara. Dengan berkembangnya aktivitas wisata kuliner serta wisata  bahari, maka perlu dilakukan pemantauan kondisi terumbu karang agar kegiatan tersebut tidak tidak memberikan dampak ekologi terhadap kondisi terumbu karang. Metode yang dipergunakan untuk menilai kondisi terumbu karang adalah  dengan metode perhitungan persentase penutupan karang hidup menggunakan Line Intercept Transect. Hasil penelitian menunjukan bahwa Kondisi terumbu karang di kedalaman 3 meter ditemukan prosentasi tutupan karang sebesar 4,5 %, sedangkan pada kedalaman 6 meter ditemukan prosentase tutupan karang sebesar 9,7 %, maka kondisi terumbu karang di perairan pantai empu rancak Mlonggo, dalam kondisi buruk sekali, namun tingginya keanekaragaman dan nilai indeks dominasi, maka diduga bahwa terumbu karang dilokasi penelitian pernah dalam kondisi baik sebelumnya. Hal ini ditunjukan dengan tingginya prosentase karang mati baik pada kedalaman 3 meter (95,54 %) maupun pada kedalaman 6 meter (90,30 %). Keanekaragaman jenis karang yang ditemukan pada kedalaman 3 meter terdiri atas 6 genus yaitu : GoniastreaSp., Favia Sp., Galaxea Sp., Porites Sp., Acropora Sp.,dan Montipora Sp.,sedangkan pada kedalaman 6 meter ditemukan keanekaraamanan jenis karang yang lebih banyak (11 genus), yaitu : Acropora sp., Favites sp., Echinopora sp., Goniastrea sp., Symphyllia agaricia, Favia sp., Goniopora sp., Porites sp., Montipora sp., Platygyra sp. ,dan Montastrea sp. Kondisi tutupan terumbu karang yang relatif buruk sekali  diduga  diakibatkan oleh menurunnya kualitas ekologi perairan yang diakibatkan oleh oleh tekanan  laju  sedimentasi serta proses  run off dari aktivitas didaratan, tingginya paparan  gelombang pada saat musim barat serta  berkembangnya  wisata kuliner serta wisata bahari  di perairan Pantai Empu rancak yang  memperburuk kondisi terumbu karang.  Kata Kunci : Terumbu Karang, pariwisata, Line Intercept Transect

scholarly journals FOREST DISTURBANCE ANALYSIS WITH LANDSAT-8 OLI DATA RELATED TO A PARAMETRIC WIND FIELD: A CASE STUDY FOR TYPHOON RAMMASUN (201409)

2018 ◽  
Vol XLII-3 ◽  
pp. 1629-1633
Author(s):  
C. Tan ◽  
W. Fang
Keyword(s):  
Remote Sensing ◽  
Wind Field ◽  
Forest Disturbance ◽  
Landsat 8 ◽  
Landsat 8 Oli ◽  
Dependence Relation ◽  
Wind Field Model ◽  
Wind Speeds ◽  
Sensing Technology ◽  
And Function

Forest disturbance induced by tropical cyclone often has significant and profound effects on the structure and function of forest ecosystem. Detection and analysis of post-disaster forest disturbance based on remote sensing technology has been widely applied. At present, it is necessary to conduct further quantitative analysis of the magnitude of forest disturbance with the intensity of typhoon. In this study, taking the case of super typhoon Rammasun (201409), we analysed the sensitivity of four common used remote sensing indices and explored the relationship between remote sensing index and corresponding wind speeds based on pre-and post- Landsat-8 OLI (Operational Land Imager) images and a parameterized wind field model. The results proved that NBR is the most sensitive index for the detection of forest disturbance induced by Typhoon Rammasun and the variation of NBR has a significant linear dependence relation with the simulated 3-second gust wind speed.

scholarly journals Analysis Comparison of Algorithms for Determination Concentration of Chlorophyll-a in Traditional and Intensive Milkfish Ponds Using LANDSAT 8 Images

2019 ◽  
Vol 1 (2) ◽  
Author(s):  
Nurhadi Bashit ◽  
Abdi Sukmono ◽  
Baskoro Agum Gumelar
Keyword(s):  
Remote Sensing ◽  
Chlorophyll A ◽  
Coastal Area ◽  
Average Concentration ◽  
The Body ◽  
Landsat 8 ◽  
Northern Coast ◽  
Fish Production ◽  
Remote Sensing Technology ◽  
Sensing Technology

Indonesia is an Archipelago Country because the Country of Indonesia consists of many islands stretching from Sabang in the west to the island of Merauke on the east. The Archipelago Country also comes from the old name of the Indonesian Country called Nusantara, because Nusantara is a country that consists of many islands. Indonesia is an Archipelago Country which means it has potential resources in the coastal areas, one of which is found on the northern coast of Java. The coastal area is an important area to be reviewed, one of which is the use of coastal resources by paying attention to the condition of the ecosystem that remains stable. Opportunities for coastal area utilization in the field of fisheries are in the form of fishing activities or fish farming, especially pond cultivation activities. Based on data from the Department of Marine and Fisheries of the Province of Central Java in 2010, pond cultivation is one of the potential resources on the coast. This potential is supported by the government to increase fish production in order to increase the consumption of fish in the community. Therefore, it is necessary to choose the most effective method of pond cultivation between traditional methods and intensive methods to optimize fish production. One indicator of effectiveness between the two methods can be seen from the phytoplankton distribution. Phytoplankton contains chlorophyll-a in the body and is a natural food from fish. Phytoplankton provides important ecological functions for the aquatic life cycle by serving as the basis of food webs in water. Phytoplankton also functions as the main food item in freshwater fish culture and seawater fish cultivation. Therefore, it is necessary to know the chlorophyll-a concentration in the ponds of traditional and intensive methods to determine the concentration chlorophyll-a of the two pond methods. One method used to determine the concentration of chlorophyll-a using remote sensing technology. Remote sensing technology can be used to determine the concentration of chlorophyll-a using the Wouthuyzen, Wibowo, Pentury, Much Jisin Arief and Lestari Laksmi algorithms. The results showed that the Pentury algorithm was relatively better to determine the concentration of chlorophyll-a in shallow waters (ponds). The lowest concentration of chlorophyll-a in traditional ponds is 0.47068 mg/m3, the highest concentration is 1.95017 mg/m3 and the average concentration is 1.12893 mg/m3, while in intensive ponds the lowest concentration is 0.36713 mg/m3, the concentration the highest is 3.17063 mg/m3 and the average concentration is 1.53556 mg/m3.

scholarly journals Reconstructing High-Precision Coral Reef Geomorphology from Active Remote Sensing Datasets: A Robust Spatial Variability Modified Ordinary Kriging Method

2022 ◽  
Vol 14 (2) ◽  
pp. 253
Author(s):  
Qi Wang ◽  
Han Xiao ◽  
Wenzhou Wu ◽  
Fenzhen Su ◽  
Xiuling Zuo ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Coral Reef ◽  
Coral Reefs ◽  
Spatial Variability ◽  
High Precision ◽  
Ordinary Kriging ◽  
Surface Model ◽  
Smoothing Effect ◽  
Geomorphological Parameters ◽  
Reef Geomorphology

Active remote sensing technology represented by multi-beam and lidar provides an important approach for the effective acquisition of underwater coral reef geomorphological information. A spatially continuous surface model of coral reef geomorphology reconstructed from active remote sensing datasets can provide important geomorphological parameters for the research of coral reef geomorphological and ecological changes. However, the surface modeling methods commonly used in previous studies, such as ordinary kriging (OK) and natural neighborhood (NN), often represent a “smoothing effect”, which causes the strong spatial variability of coral reefs to be imprecisely reflected by the reconstructed surfaces, thus affecting the accurate calculation of subsequent geomorphological parameters. In this study, a spatial variability modified OK (OK-SVM) method is proposed to reduce the impact of the “smoothing effect” on the high-precision reconstruction of the complex geomorphology of coral reefs. The OK-SVM adopts a collaborative strategy of global parameter transformation, local residual correction, and extremum correction to modify the spatial variability of the reconstructed model, while maintaining high local accuracy. The experimental results show that the OK-SVM has strong robustness to spatial variability modification. This method was applied to the geomorphological reconstruction of the northern area of a coral atoll in the Nansha Islands, South China Sea, and the performance was compared with that of OK and NN. The results show that OK-SVM has higher numerical accuracy and attribute accuracy in detailed morphological fidelity, and is more adaptable in the geomorphological reconstruction of coral reefs with strong spatial variability. This method is relatively reliable for achieving high-precision reconstruction of complex geomorphology of coral reefs from active remote sensing datasets, and has potential to be extended to other geomorphological reconstruction applications.

scholarly journals STATUS TERUMBU KARANG DI PERAIRAN PESISIR NEGERI HUKURILA

2021 ◽  
Vol 17 (1) ◽  
pp. 35-45
Author(s):  
Dicky Sahetapy ◽  
Laura Siahainenia ◽  
Debby A J Selanno ◽  
Johannes M S Tetelepta ◽  
Novianty C Tuhumury
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Coastal Waters ◽  
Coral Species ◽  
Similarity Index ◽  
Ecological Index ◽  
Stony Coral ◽  
The Status ◽  
Coral Communities ◽  
Line Intercept

Coral reef is one of the important coastal ecosystems that have high biodiversity. This study aims to analyze the composition of the taxa and the distribution of coral species, the ecological index of coral communities and the status of coral reefs. The research was conducted from April-May 2019 in the coastal waters of Hukurila Village, South Leitimur District, Ambon City. Collecting coral data by using the Line Intercept Transect (LIT) method. Determination of coral reef condition based on percent data (value) of coral reef cover. During the study, 116 species of stony coral from 49 genera and 16 families were found, which 50 species of them are protected and 23 species of ornamental coral. The similarity index of stony coral species between coral reef locations ranges from 0.52-0.76 or there is the similarity of stony coral species between locations coral reef in the amount of 52-76%. The coral reefs of Hukurila Village have high diversity of coral species, with a low dominance of coral species in the community, and the compatibility of coral species in the community is classified as stable. Acropora corals contributed a low covering percent value (9.98%), while Non-Acropora corals contributed a relatively high percent of covering value (43.56%). The status of coral reefs between locations in the coastal waters of Hukurila Village is in the criteria of good (healthy).   ABSTRAK Terumbu karang merupakan salah satu ekosistem pesisir penting yang emiliki kenanekaragaman hayati tinggi. Penelitian ini bertujuan untuk menganalisis komposisi taksa dan sebaran spesies karang, indeks ekologi kominitas karang dan status terumbu karang. Penelitian dilakukan dari April-Mei 2019 di perairan pesisir Negeri Hukurila Kecamatan Leitimur Selatan Kota Ambon. Pengumpulan data karang menggunakan metode Line Intercept Transect (LIT). Penentuan kondisi terumbu karang berdasarkan data (nilai) persen penutupan karang batu. Selama penelitian ditemukan 116 spesies karang batu dari 49 genera dan 16 famili, dimana 50 spesies diantaranya dilindungi dan 23 spesies karang hias. Indeks similaritas spesies karang batu antar stasiun terumbu karang berkisar antara 0,52-0,76 atau terdapat kesamaan spesies karang batu antar lokasi terumbu karang sebesar 52-76%. Terumbu karang Negeri Hukurila memiliki diversitas spesies karang tinggi, dengan dominansi spesies karang rendah dalam komunitas, dan keserasian spesies karang dalam komunitas tergolong stabil. Karang Acropora memberi kontribusi nilai persen penutupan rendah (9,98%), sementara karang Non-Acropora memberi kontribusi nilai persen penutupan karang batu relatif tinggi (43,56%). Status terumbu karang antar stasiun terumbu perairan pesisir Negeri Hukurila berada dalam kriteria baik (sehat).   Kata kunci: terumbu, karang batu, keragaman spesies, kesamaan, persen penutupan

scholarly journals Analysis Condition of Coral Reef Covering in Pramuka Island Waters, Seribu Islands using Line Intercept Transect (LIT) Method

2020 ◽  
Vol 2 (2) ◽  
pp. 77
Author(s):  
Rega Permana ◽  
Nora Akbarsyah ◽  
Pringgo KDNY Putra ◽  
Aulia Andhikawati
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Coral Cover ◽  
Life Forms ◽  
Anthropogenic Factors ◽  
Coral Reef Ecosystem ◽  
Marine Tourism ◽  
Tourist Destinations ◽  
Line Intercept ◽  
Reef Ecosystem

The coral reef ecosystem is one of the typical tropical ecosystems with high biodiversity which has an important role both biologically, ecologically, physically as well as socially and economically. Several coral reef areas in Indonesia were reported to have suffered damage, not only due to climate change which has an impact on rising sea surface temperatures and ocean acidification but also due to anthropogenic factors and irresponsible management of marine tourism. This study aimed to analyze the condition of coral reefs based on covering in Pramuka Island, which is one of the famous tourist destinations in the Seribu Islands. The study was conducted using Line Intercept Transect (LIT) method at predetermined coordinate points. The results showed that the dominant coral reef life form was Acropora Submassive (ACS), namely 18.9%, and Acropora Branching (ACB) as much as 12.48%. Besides, the types of life forms found were coral foliase (9.42%), Miliepora Coral (9.2%), Coral Massive (4.8%), Acropora Encrustring (4.24%), and so on. Based on the results of this study, it can be concluded that the condition of coral reefs in Pramuka Island is still relatively good with a total coral cover percentage of 72.38%. Efforts to protect the coral reef ecosystem in this area need to be considered so that its condition can be maintained. 

scholarly journals Assessment of Land Use and Vegetative Cover in Kano Metropolis (from 1975-2015) Employing GIS and Remote Sensing Technology

2020 ◽  
Vol 27 (2) ◽  
pp. 1-7
Author(s):  
M. Haruna ◽  
M.K. Ibrahim ◽  
U.M. Shaibu
Keyword(s):  
Remote Sensing ◽  
Land Use ◽  
Agricultural Land ◽  
Landsat 8 ◽  
Vegetative Cover ◽  
Gis And Remote Sensing ◽  
Remote Sensing Technology ◽  
Sensing Technology ◽  
Agricultural Planning ◽  
Bare Land

This study applied GIS and remote sensing technology to assess agricultural land use and vegetative cover in Kano Metropolis. It specifically examined the intensity of land use for agricultural and non agricultural purpose from 1975 – 2015. Images (1975, 1995 and 2015), landsat MSS/TM, landsat 8, scene of path 188 and 052 were downloaded for the study. Bonds for these imported scenes were processed using ENVI 5.0 version. The result indicated five classified features-settlement, farmland, water body, vegetation and bare land. The finding revealed an increase in settlement, vegetation and bare land between 1995 and 2015, however, farmland decreased in 2015. Indicatively, higher percentage of land use for non agricultural purposes was observed in recent time. Conclusively, there is need to accord surveying the rightful place and priority in agricultural planning and development if Nigeria is to be self food sufficient. Keywords: Geographic Information System, Agriculture, Remote sensing, Land use, Land cover

scholarly journals Confidence Levels, Sensitivity, and the Role of Bathymetry in Coral Reef Remote Sensing

2020 ◽  
Vol 12 (3) ◽  
pp. 496 ◽  
Author(s):  
James A. Goodman ◽  
Mui Lay ◽  
Luis Ramirez ◽  
Susan L. Ustin ◽  
Paul J. Haverkamp
Keyword(s):  
Remote Sensing ◽  
Coral Reef ◽  
Coral Reefs ◽  
Water Depth ◽  
Data Availability ◽  
Sensor Technology ◽  
Internal Quality ◽  
Benthic Habitat ◽  
Model Output ◽  
Confidence Levels

Remote sensing is playing an increasingly important role in the monitoring and management of coastal regions, coral reefs, inland lakes, waterways, and other shallow aquatic environments. Ongoing advances in algorithm development, sensor technology, computing capabilities, and data availability are continuing to improve our ability to accurately derive information on water properties, water depth, benthic habitat composition, and ecosystem health. However, given the physical complexity and inherent variability of the aquatic environment, most of the remote sensing models used to address these challenges require localized input parameters to be effective and are thereby limited in geographic scope. Additionally, since the parameters in these models are interconnected, particularly with respect to bathymetry, errors in deriving one parameter can significantly impact the accuracy of other derived parameters and products. This study utilizes hyperspectral data acquired in Hawaii in 2000–2001 and 2017–2018 using NASA’s Classic Airborne Visible/Infrared Imaging Spectrometer to evaluate performance and sensitivity of a well-established semi-analytical inversion model used in the assessment of coral reefs. Analysis is performed at several modeled spatial resolutions to emulate characteristics of different feasible moderate resolution hyperspectral satellites, and data processing is approached with the objective of developing a generalized, scalable, automated workflow. Accuracy of derived water depth is evaluated using bathymetric lidar data, which serves to both validate model performance and underscore the importance of image quality on achieving optimal model output. Data are then used to perform a sensitivity analysis and develop confidence levels for model validity and accuracy. Analysis indicates that derived benthic reflectance is most sensitive to errors in bathymetry at shallower depths, yet remains significant at all depths. The confidence levels provide a first-order method for internal quality assessment to determine the physical extent of where and to what degree model output is considered valid. Consistent results were found across different study sites and different spatial resolutions, confirming the suitability of the model for deriving water depth in complex coral reef environments, and expanding our ability to achieve automated widespread mapping and monitoring of global coral reefs.

The scientific issues surrounding remote detection of submerged coral ecosystems

1998 ◽  
Vol 22 (2) ◽  
pp. 190-221 ◽  
Author(s):  
Heather Holden ◽  
Ellsworth LeDrew
Keyword(s):  
Remote Sensing ◽  
Coral Reef ◽  
Coral Reefs ◽  
Large Scale ◽  
Aerial Photographs ◽  
Coastal Zones ◽  
Global Status ◽  
Coral Reef Ecosystems ◽  
Remote Estimation

According to the 1993 colloquium on the ‘Global status of coral reefs', our understanding of the global role of coral reefs is inadequate. To increase our understanding, an accurate large-scale mapping and monitoring programme is necessary. Historically, coastal zones have been mapped using traditional surveying tools such as topographic maps, nautical charts, existing aerial photographs and direct observations. Although less expensive than digital imagery, exclusive use of these traditional tools may not be practical for monitoring large or remote coral reef ecosystems accurately. Researchers are attempting to develop an adequate coral reef mapping system based on digital remote sensing, but are impeded by issues such as effects of the intervening water column and spectral distinction of bottom types. The two variables discussed, which will contribute to our understanding of the global role of coral reefs, are: 1) remote sensing of submerged coral reefs in general; and 2) remote sensing of coral bleaching in particular. A summary of radiative transfer theory is presented and case studies of attempts at mapping remotely the geographic extent and health of submerged ecosystems, as well as a discussion of the remote estimation of water depth and quality. Problems in the translation and delivery of information to the end user are presented, and possible solutions suggested.

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