Development of Secondary Forest Succession Based on Estimation of Forest Carbon Stocks Ten Years Post-Merapi Volcano Eruption

The eruption of the most active volcano in Indonesia, Mount Merapi, has resulted in a very dynamic landscape as a form of ecosystem succession. This study aimed to analyze the carbon stock and vegetation composition in the secondary forest with variations in the level of disturbance after the 2010 eruption of Mount Merapi. Data collection was carried out in January 2020, in which biomass, necromass, and soil organic carbon data were taken in plot transect and Geographic Information Systems carbon stock products compared field data. The results showed that secondary forests at stations A and B with low and medium disturbance levels had carbon stocks in the high category. In contrast, station C at Cangkringan Resort, with high disturbance levels, still had carbon stock with a low category. Furthermore, the comparison of 2020 field data with GIS carbon stock products concluded a similar pattern between carbon stock from aboveground biomass WHRC 2010 and belowground biomass NASA 2010. This research concludes that the disturbance affected forest carbon stocks ten years after the 2010 Merapi eruption. Therefore, monitoring the vegetation community needs to be carried out annually through a combination of spatial and direct checks in the field

The Abundance and Characteristics of Microplastics in The Sediments of the Progo River of Yogyakarta, Indonesia

Microplastics may pollute water bodies and endanger living things. The Progo River, one of the longest rivers crossing Yogyakarta Province, has been used as a source for drinking water for residents. However, plastic waste as a source of microplastics is tremendously high in this river. The objective of this study is to analyze the abundance and characteristics of microplastics in the sediments of the Progo River. Sediment sampling was administered in December 2019 at six stations in the upstream, midstream, and downstream rivers. The results showed that all sediment samples from upstream to downstream of the Progo River were found to contain microplastics with an abundance range of 209.37 to 1173.25 particles kg-1. The highest microplastic abundance was found in the downstream area of 645.34 ± 405.94 particles kg-1, followed by the midstream of 480.23 ± 174.09 particles kg-1, and the upstream part of 276.85 ± 73.70 particles kg-1. Microplastics in the Progo River sediments both in the upstream, midstream, and downstream areas are dominant in size of 100 - 500 µm, fibers, and transparent in color. The type of polymer identified in each sample is polyester which is widely used for textile fibers due to the discharge of the residents’ laundry washing water into the river. The Progo River, which is one of the top 20 dirtiest rivers globally, has a high abundance of microplastics after Jakarta and Karimun Jawa’s rivers. Seeing the high number of microplastic abundance, the Indonesian government must immediately include microplastic parameters to regulate environmental quality standards

Microplastics pollution in sediment of Serang River Kulon Yogyakarta Province

Microplastics that can harm living things have been found in large rivers in Yogyakarta Province to the digestive tract of fish. However, rivers in the suburban areas of the province, such as the Serang River, have not yet been identified, although many local communities still use them. This study aimed to analyze the abundance, type of polymer, and characteristics of microplastics found in Serang River sediments. Sampling was carried out in December 2019 in the upstream, midstream, and downstream areas of the river. Six sediment samples were taken from each area and randomly divided into two stations. Each sediment sample was then dried, weighed dry, separated the microplastics, observed visually, calculated the abundance of microplastics, grouped shape, size, and color (characteristics), identified the type of polymer by Fourier-transform infrared spectroscopy (FTIR) test, and analyzed quantitatively descriptively and inferentially. The results showed that microplastics were present in all samples with an abundance range of 148.88 to 384.58 particles kg-1. The abundance of microplastics in Serang River sediments was highest in the downstream area, with an average of 321.99 ± 46.76 particles kg-1. The microplastic was identified as a polyethylene polymer as the main ingredient for making single-use plastics. The characteristics of microplastics in Serang River sediments are dominated by a size range of 10-50 m, in the form of fragments and films, and transparent colors

Monitoring Aerosol Optical Depth for Air Quality Through Himawari-8 in Urban Area West Java Province Indonesia

Air quality is a crucial parameter in human life. One air quality indicator can be observed through Aerosol Optical Depth (AOD). If these substances are pollutants such as particulate matter, aerosols, and ozone, it is confident that air quality will deteriorate, threatening human health and causing climate change. AOD monitoring can be used as a basis for policymakers and related parties to maintain the stability of air quality in the atmosphere. Many ground observation stations monitor air quality by obtaining data on PM2.5 and PM10 aerosol particles. However, the number of ground stations is limited, resulting in incomplete data. Fortunately, remote sensing satellites have the advantage of covering large areas and providing continuous observations, with the ability to gather information on large-scale aerosol and obtain spatiotemporal distribution. Therefore, this research aims to obtain AOD through Himawari-8 and analyze the spatiotemporal air quality in urban areas of West Java based on AOD. The research methodology used in this study is descriptive analysis with an empirical research approach. Assisted by remote sensing technology and Geographic Information Systems, this research generates AOD data extraction that can be obtained from the new generation satellite of Himawari-8. The distribution of AOD levels and spatiotemporal monitoring in urban areas of West Java is very dynamic depending on anthropogenic activity in a particular area and time.   Keywords: Aerosol Optical Depth (AOD), Air Quality, Himawari-

Spatial Prioritization for Wildfire Mitigation by Integrating Heterogeneous Spatial Data: A New Multi-Dimensional Approach for Tropical Rainforests

Wildfires drive deforestation that causes various losses. Although many studies have used spatial approaches, a multi-dimensional analysis is required to determine priority areas for mitigation. This study identified priority areas for wildfire mitigation in Indonesia using a multi-dimensional approach including disaster, environmental, historical, and administrative parameters by integrating 20 types of multi-source spatial data. Spatial data were combined to produce susceptibility, carbon stock, and carbon emission models that form the basis for prioritization modelling. The developed priority model was compared with historical deforestation data. Legal aspects were evaluated for oil-palm plantations and mining with respect to their impact on wildfire mitigation. Results showed that 379,516 km2 of forests in Indonesia belong to the high-priority category and most of these are located in Sumatra, Kalimantan, and North Maluku. Historical data suggest that 19.50% of priority areas for wildfire mitigation have experienced deforestation caused by wildfires over the last ten years. Based on legal aspects of land use, 5.2% and 3.9% of high-priority areas for wildfire mitigation are in oil palm and mining areas, respectively. These results can be used to support the determination of high-priority areas for the REDD+ program and the evaluation of land use policies

Potential Loss of Ecosystem Service Value Due to Vessel Activity Expansion in Indonesian Marine Protected Areas

Sustainable Development Goal (SDG) number 14 pertains to the preservation of sustainable marine ecosystems by establishing marine protected areas (MPAs). However, studies have reported massive damage to Indonesian marine ecosystems due to shipping pollution, anchors, and fishing nets. Thus, this study estimated the potential loss of ecosystem service value due to vessel activity expansion in the MPAs of Indonesia. This study was divided into three stages. The first stage is vessel activity expansion zone modeling based on kernel density. The second stage is marine ecosystem service value modeling through semantic harmonization, reclassification, and spatial harmonization. The last stage is the overlay of the vessel expansion zone model, marine ecosystem service value model, and the MPA of Indonesia. The results of this study indicate that the marine neritic zone of Indonesia has an ecosystem service value of USD 814.23 billion, of which USD 159.87 billion (19.63%) are in the MPA. However, the increase in vessel activity that occurred in 2013–2018 could potentially lead to the loss of the ecosystem service value of USD 27.63 billion in 14 protected areas. These results can assist policymakers in determining priority conservation areas based on the threat of vessel activity and value of ecosystem services.</p

Spatial integration framework of solar, wind, and hydropower energy potential in Southeast Asia

Amid its massive increase in energy demand, Southeast Asia has pledged to increase its use of renewable energy by up to 23% by 2025. Geospatial technology approaches that integrate statistical data, spatial models, earth observation satellite data, and climate modeling can be used to conduct strategic analyses for understanding the potential and efficiency of renewable energy development. This study aims to create the first spatial model of its kind in Southeast Asia to develop multi-renewable energy from solar, wind, and hydropower, further broken down into residential and agricultural areas. The novelty of this study is the development of a new priority model for renewable energy development resulting from the integration of area suitability analysis and the estimation of the amount of potential energy. Areas with high potential power estimations for the combination of the three types of energy are mostly located in northern Southeast Asia. Areas close to the equator, have a lower potential than the northern countries, except for southern regions. Solar photovoltaic (PV) plant construction is the most area-intensive type of energy generation among the considered energy sources, requiring 143,901,600 ha (61.71%), followed by wind (39,618,300 ha; 16.98%); a combination of solar PV and wind (37,302,500 ha; 16%); hydro (7,665,200 ha; 3.28%); a combination of hydro and solar PV (3,792,500 ha; 1.62%); and a combination of hydro and wind (582,700 ha; 0.25%). This study is timely and important because it will inform policies and regional strategies for transitioning to renewable energy, with consideration of the different characteristics present in Southeast Asia

Spatial integration framework of solar, wind, and hydropower energy potential in Southeast Asia

Amid its massive increase in energy demand, Southeast Asia has pledged to increase its use of renewable energy by up to 23% by 2025. Geospatial technology approaches that integrate statistical data, spatial models, earth observation satellite data, and climate modeling can be used to conduct strategic analyses for understanding the potential and efficiency of renewable energy development. This study aims to create the first spatial model of its kind in Southeast Asia to develop multi-renewable energy from solar, wind, and hydropower, further broken down into residential and agricultural areas. The novelty of this study is the development of a new priority model for renewable energy development resulting from the integration of area suitability analysis and the estimation of the amount of potential energy. Areas with high potential power estimations for the combination of the three types of energy are mostly located in northern Southeast Asia. Areas close to the equator, have a lower potential than the northern countries, except for southern regions. Solar photovoltaic (PV) plant construction is the most area-intensive type of energy generation among the considered energy sources, requiring 143,901,600 ha (61.71%), followed by wind (39,618,300 ha; 16.98%); a combination of solar PV and wind (37,302,500 ha; 16%); hydro (7,665,200 ha; 3.28%); a combination of hydro and solar PV (3,792,500 ha; 1.62%); and a combination of hydro and wind (582,700 ha; 0.25%). This study is timely and important because it will inform policies and regional strategies for transitioning to renewable energy, with consideration of the different characteristics present in Southeast Asia

Characteristics of False-Positive Active Fires for Biomass Burning Monitoring in Indonesia from VIIRS Data and Local Geo-Features

In this study, we explored the characteristics of thermal anomalies other than biomass burning to establish a zone map of false-positive active fires to support efficient ground validation for firefighters. We used the ASCII file of VIIRS active fire data (VNP14IMGML), which provides attributes of thermal anomalies every month from 2012 to 2020 in Indonesia. The characteristics of thermal anomalies other than biomass burning were explored using fire radiative power (FRP) values, confidence levels of active fire, fire pixel areas, and their allocations to permanent geographical features (i.e., volcano, river, lake, coastal line, road, and industrial/settlement areas). The Tukey test showed that there was a significant difference between the mean FRP values of the other thermal anomalies, type-1 (active volcano), type-2 (other static land sources), and type-3 (detection over water/offshore), at a confidence level of 95%. Most thermal anomalies other than biomass burning were in the nominal confidence level with a fire pixel area of 0.21 km2. High spatial images validated these thermal anomaly types as false positives of biomass burning. A zone map of potential false-positive active fire for biomass burning was established in this study by referring to the allocation of thermal anomalies from permanent geographical features. Implementing the zone map removed approximately 13% of the VIIRS active fires as the false positive of biomass burning. Insights gleaned through this study will support efficient ground validation of actual forest/land fires