This study explored the use of participatory mapping and several machine learning algorithms (Naïve Bayes, GMO Maxent, SVM, CART, and Random Forest) to map climate induced landslide susceptibility in Lembeh Island, North Sulawesi, based on Earth Observation data available in Google Earth Engine. Participatory mapping on landslide incidents were conducted in three villages, i.e., Kareko, Pintu Kota, and Pasir Panjang. Data used include digital elevation model from SRTM, multispectral imageries from Sentinel 2, and precipitation from CHIRPS. Terrain modelling was done to DEM to come up with elevation, slope, curvature, and aspect. A cloud free mosaic of Sentinel Images was created using the median reducer and then NDVI was calculated. Precipitation data from CHIRPS was sampled and interpolated using kriging and reduced to maximum and mean. Each algorithm was trained using 70% participatory mapping data and then the prediction was tested for accuracy using the last 30%. Results showed that Random Forest, SVM, CART, and GMO Maxent gave 0.98 testing accuracy and Naïve Bayes only 0.90. The map showed that due to the terrain condition, Lembeh Island is prone to Landslide and even though previously BNPB already provide a landslide hazard risk map, there were many areas not included on that map. Therefore, the map could become an input for BNPB and the Bitung City for developing a mitigation and adaptation strategy. Machine learning and cloud computing along with participatory mapping could also complement mechanistic or multi-criteria analysis using GIS model for landslide susceptibility mapping.

Indonesia as an archipelagic country has a high biodiversity of coral reefs but is very vulnerable to various threats, one of the causes of damage to coral reefs is by ship aground. The damage causes minor injuries to the degradation of the reef structure. The location of the grounding sometimes on the small islands with calm currents, but sometimes in straits with strong currents. However, the assessment must be carried out, so it is necessary to develop an approach to assessing that. The purpose of this study is to assess the damage of coral reefs, to quantify the extent of damage, and identify species of corals affected. The observation used ground truth (underwater photo transect), aerial photography, machine learning, and species distribution modeling. The results obtained from aerial photography show that the MV Pazifik has damage to coral reefs reaching 613.63 m2. Based on the coral genera distribution model, it was found 35–55 genera (control location), while at the ship aground, were found 3–5 genera. Therefore, the control location is a coral reef ecosystem that is dominated by corals, while at the ship aground it can be the habitat for several hard coral genera.

Resilience is the ability of a system to reach equilibrium after a temporary disturbance. When an ecosystem is disturbed, then the recovery of the system is very dependent on the diversity of species that are still left. The remaining communities determine the direction of new successional communities formed after the disturbance has passed, including coral, fish, and other biota communities. This study aimed to determine the level of resilience of coral reef ecosystems on Lembeh Island. The observation was carried out from January 16-19, 2019, at a 7-meter depth. Determination of the coral reef index will refer to coral reef resilience index table. It is found that the resilience of coral reefs on Lembeh Island currently has a high potential for recovery (resilience) from natural stressors based on the 16 parameters. Seven parameters have very high resilience values: the proportion of bleaching resistant species, community resistance to bleaching, taxonomic diversity, size/age distribution, the abundance of reef fish on live coral, and the abundance of coral benthos on live coral and coral disease levels. Lembeh Island is dominated by hard corals measuring between 5.1 to 25 cm (size M) by ~46%, then sizes more than 25 cm (size L) by ~37% and juvenile size (size S) by 17%. The coral health index on Lembeh Island has the capacity to recover if the condition of coral cover is minimally maintained or improved and lower fleshy seaweed cover by increasing the abundance and biomass of herbivorous fish.

Belitung has potential coral reefs as many as 244 species and 89 species of reef fish. However, the current condition of coral reefs in Belitung is under high pressure, caused by illegal tin mining activities. For this reason, need studies related to their impact on the health of marine life, especially on coral reefs so that the policy can be reviewed, to see the important role of coral reefs for other marine biotas. The aim of this study is focused on knowing the condition of substrate coverage, diversity, and biomass of target fish as well as assessing the health of coral reefs at the observation site. Data were collected with SCUBA diving equipment at 6 stations, at depth of 5–1 m. Retrieval of basic substrate data is done by the Underwater Photo Transect method and for reef fish using belt transect. The results showed substrate coverage was dominated by hard corals, dead corals, sand, and dead corals with algae. Fleshy seaweed cover ranges from 0.07–4.77%, coral fragment cover ranges from 0–2.6%, target fish biomass value obtained varies between 0.0006–0.0299 kg/ha, and coral reef health index at each observation station ranges from 3 to 6.

Optical device is a telecommunications device that uses glass or plastic media made from silica and SiO 2 to transmit data using light or LED (Light Emitter Diode) as the data is transmitted. Silica is one of the materials / media that serves as the transmission of data on the component microring resonator. This paper, investigate about the characteristic of microring resonator and specifically about the temperature effect on the cascaded parallel microring resonator. In this paper, also explains the resistance of the microring resonator for the various temperatures are given. How big is the change in the wavelength shift is happening and how the resulting output of wavelength. A cascaded parallel microring resonator is simulated using MatLab to analyze the temperature effect on the ring resonator components. This simulation also uses the couple mode theory to get the value of coupling coefficient. The wavelength used in this simulation was C-Band between 1530-1565 μm. The simulations result shows the resistance of the components cascade-parallel microring resonator for a certain temperature. The simulated temperature are varied between 28 o Celcius to 500 o Celsius. Based on the simulation result it can be concluded that the change in temperature will change the resonance wavelength. As the temperature is increased, the resonance wavelength shifts (The increased temperature will affect to the shifting of resonance wavelength). The results of this study, a temperature parameters are given to the resilience of the microring resonator.