Indonesian Journal of Geography
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Remotely-Sensed Derived Built-up Area as an Alternative Indicator in the Study of Thailand’s Regional Development
Get PDFNowadays measuring national and regional development primarily relies on demographic and socio-economic indicators. An indicator in physical dimension e.g., areas of human settlements and their economic uses of lands is usually ignored due to unavailability of data in countries like Thailand. Remotely-sensed derived built-up area was used, for the first time, as a physical indicator for studying Thailand’s regional development. Remote sensing - using the decision tree classifier with the combination indices of band ratios, NDVI, MNDWI, and NDBI - and GIS techniques were utilized to estimate the regional proportion of built-up area. The relationships between the percentage of the derived built-up area and the three development indicators - urbanization rate, Gross Regional Product, and Human Achievement Index - were analyzed. Resultantly, the estimate of the 2019 derived built-up area in Thailand was 2.46% with the average accuracy of 84.5%. Regional variation in development levels existed and relationships between the percentage of built-up area and the three development indicators for the regions were strong. However, there was no relationship after excluding the region having the effect of Bangkok. Therefore, remotely-sensed derived built-up area gives new information and is suggested for use for the analysis of Thailand’s regional development
The Relationship between Population Dynamic and Garang River Upstream Environment in Central Java, Indonesia
Get PDFThe interaction of the human population with nature can cause environmental damage such as the degradation of the watershed carrying capacity. Therefore, this study aimed to analyze the relationship between population dynamic and the upstream environment alongside Garang River using four villages including Munding, Lerep, Kalirejo, and Pakintelan. Data were collected from several stakeholders including selected heads of households supported by key informants such as community leaders and the river care communities using field observation, a household survey through questionnaires, in-depth interviews, and documentation. The households used as samples were selected through proportional random sampling and the data retrieved were analyzed through a descriptive quantitative method which involved the cross-tabulation of household data on economic activities and environmental management practices. It was discovered that 1) the population of the Garang River’s upstream was very dynamic with growth rates varying from 1.05% to 3.93%, 2) the main livelihood of the population and dominant land use was the agricultural sector, 3) the community realized that the harmonic relationship with the environment was a critical condition to support farming activities and fulfil daily necessities, and 4) the society kept maintaining the river through different activities such as "bersih sungai" or river cleaning and "sedekah bumi" or thank-giving to the environment. Moreover, the harmonic relationship between the people and the river environment is in form of several activities. These included waste management, cleaning rivers, maintaining clean waterways, actions to create a clean and healthy environment, and joining the efforts to care for the environment. The harmony was observed to have been realized through the integration of diversity, interdependence, unity, and the value of providing care
Flood Disaster Risk Model in Karawang Regency's Industrial Area, West Java Province, Indonesia
Get PDFTelukjambe Barat and Telukjambe Timur Sub-Districts, Karawang Regency, have a high flood risk level due to changes in Land Use/Land Cover and the yearly occurrence of runoff water discharge. This research aims to analyze the rate and pattern of land-use change due to industrial development, examine the correlation of flood impacts with environmental-socio-economic factors, and develop a flood risk model in industrial areas. Data were collected through methods of system dynamics, remote sensing, geographic information system, questionnaire distribution, focus group discussions, and in-depth interviews with stakeholders. The results showed that floods in this regency are due to massive inland changes, such as the transition from vegetation and water bodies to industrial and residential areas and a strong relationship between environmental-social-economic factors. In other cases, areas with urban land conversion are likely to be flood-prone zones in places such as the Philippines, Belgium, and China. Based on the correlation test that has been conducted, the relationship with the highest level of closeness is the correlation between environmental factors and the impact of flooding, which has a value of 0.791. Therefore, the disaster risk model with an integrated spatial plan approach and an ecological perspective is an option for realizing sustainable development in industrial areas in Karawang Regency
Spatial Analysis of Health and Physical Parameters of the Mangrove Forest at Taman Hutan Raya Ngurah Rai, Bali Using Sentinel-2A
Get PDFMangrove forest is a very valuable forest, but despite its benefits mangrove forest continue to be degraded due to human activities. The purpose of this study was to map the distribution and to analyze mangrove forests’ health based on the NDVI vegetation index value and environmental quality. Distribution of mangrove forest health was obtained through the processing of sentinel 2-A satellite imagery in 2020 and field measurements. The environmental quality of the mangrove forest was obtained by processing the physical parameters which are water temperature, water salinity, water pH, and substrate texture using the Ordinary Kriging method. The health of the mangrove forest of Taman Hutan Raya Ngurah Rai is dominated by healthy category mangroves. The health of the mangrove forest worsens when closer to the shore and riverbanks. Mangrove vegetation with good conditions tends to have optimal environmental quality conditions and vice versa
Carbon Sequestration of Fruit Trees under Contrasting Management Regimes
Get PDFThis study aimed at establishing the potential of fruit trees in carbon sequestration. The specific objectives were to establish the carbon stocks in fruit trees compare the potential of carbon stocks in citrus and mango trees and examine the relationship between the management practices and carbon stocks in fruit trees. At the farm level, plots were identified and transects established and individual fruit trees from sampled individual farms along the transect were selected. At the tree level, measurements of tree height and diameter at breast height were made. They were converted to biomass using allometric equations. Analysis of Variance was used to compare the differences in carbon stocks between the fruit trees and between the different management practices. Findings revealed higher biomass and carbon stocks in mango trees as compared to citrus (74.57 ± 14.95 and 13.52 ± 1.25 t/ha respectively). Significant differences are also reported in carbon stocks under different management practices (p < 0.05). Irrespective of the species type, above-ground carbon under different management practices followed the order (from highest to lowest): Inorganic fertilizer < Intercrop < Monocrop < organic fertilizer and irrigation < intercrop and inorganic fertilizer. The results also point out that mango fruits have a high potential to sequestrate carbon emissions hence mitigating global warming
Biomass carbon stock assessment of mangrove ecosystem in Pannikiang Island South Sulawesi Indonesia
Get PDFOne of the essential services provided by mangroves is carbon sequestration, and therefore climate change mitigation. While previous assessments of mangrove carbon stocks and sequestrations have focused on the estuarine and deltaic mangrove setting, there are still limited studies carried out at small island mangroves. The study aims to assess mangrove biomass carbon stocks in Pannikiang, a small island in South Sulawesi, Indonesia, which occupies 91.64 ha of species-rich pristine mangrove forests. A field-based data collection survey was performed using a circular plot approach, while above-ground tree carbon (AGC) and below-ground root carbon (BGC) stocks were estimated using available species-specific allometric equations. The mean AGC and BGC were 5.34 ± 0.17 and 1.68 ± 0.04 Mg C ha-1, respectively. Bruguiera gymnorrhiza mangrove species stored the greatest of carbon stocks, followed by Scyphiphora hydrophyllacea. Carbon stocks obtained from small island mangroves in this study were lower than stocks assessed from other mangrove locations across Indonesia and Southeast Asia. However, historical rates of deforestation in Pannikiang Island may generate emissions to approximately 82.17 Mg CO2-eq. Findings from this study will be beneficial in providing baseline data for policy decision-making on climate change mitigation in the region, specifically for improved land use management via a low carbon development agenda
Influence of Spatial Abilities on Spatial Data Quality in Participatory Mapping
Get PDFParticipatory mapping (PM) method has become an alternative in spatial data collection activities for various mapping activities, including updating data on Rural & Urban Land and Building Tax (PBB-P2). From several experiences in PM application, various quality results have been found. Differences in the levels of spatial abilities of PM actors are assumed to affect the quality levels of PM results. Therefore, this study aimed to determine the effects of spatial abilities on the quality of spatial data generated in PM activities. It consisted of several stages of preparing instruments for measuring spatial abilities, collecting spatial data through PM, and correlation analysis. The instrument used to measure the levels of spatial abilities of 28 subvillage chiefs was the Purdue Spatial Visualization Test. The quality of PBB-P2 spatial data in 28 subvillages was randomly selected and assessed in terms of position, area, and geometric accuracies with reference to the land registration map from National Land Agency. Results indicated a positive correlation between the visual spatial ability and the spatial data quality of the PM results with a value of r = 0.823. Our findings are expected to be used as references for parties who carry out PM activities to be able to plan such activities
Prediction and Simulation of Land Use and Land Cover Changes Using Open Source QGIS. A Case Study of Purwokerto, Central Java, Indonesia
Get PDFPopulation size multiplies along with the increasing need for residential space. As often occurs in developing cities like Purwokerto, population growth is associated with land use/land cover (LULC) change to accommodate housing demand both in the present and future. Therefore, this study was intended to map LULC changes in three different years: 2008, 2013, and 2018, and predict the change in 2023. For LULC data extraction, a pixel-based digital classification with a maximum likelihood algorithm was applied to Landsat images. In addition, the LULC change prediction was modeled with Modules for Land Use Change Simulations (MOLUSCE) from the QGIS plugins. It used two algorithms: artificial neural network (ANN) with a multilayer perceptron (MLP) and cellular automata (CA). The LULC classifications for 2008, 2013, and 2018 were 88%, 86%, and 88% accurate, while the prediction was 75.26% accurate, with a kappa of 0.634. Predictions and simulations indicate fluctuations in LULC change in the City of Purwokerto periodically, especially for built-up land, showing growth that continues to increase significantly
Utilization of Gravimetric Satellite Data for Delineating of Subsurface Model of The Purwokerto-Purbalingga Groundwater Basin
Get PDFThe utilization of gravimetric satellite data has been carried out to delineate the subsurface model of the Purwokerto-Purbalingga Groundwater Basin. Access and processing of satellite gravity anomalies data were carried out to obtain the residual gravity anomalies data. Modeling of the residual gravity anomalies data was conducted along the AA′, BB′, and CC′ trajectories. The modeling results show a basin model filled by alluvial deposits (1.75 g/cm3 and 2.28 g/cm3) with a maximum depth of about 402 m for the AA′ trajectory, 543 m for the BB′ trajectory, and 463 m for the CC′ trajectory. The modeling results show that this alluvial basin is delimited by impermeable and semi-impermeable layers, which include laharic deposits of Slamet Volcano (2.61 g/cm3), andesite lava deposits (2.90 g/cm3), Tapak formation rocks (2.50 g/cm3), breccia rocks of Tapak formation (2.70 g/cm3), and breccia rocks of Halang formation (2.80 g/cm3). The fairly large thickness of alluvial deposits supported by dug-well water tables data and resistivity data indicates that the potential of groundwater in the Purwokerto-Purbalingga Groundwater Basin area is very large. The results of the study are expected to be a solution to overcome droughts that often occur in the Banyumas and Purbalingga regencies, as well as for the development of groundwater-based irrigation
Green Open Space Priority Modelling Using GIS Analysis in West Jakarta
Get PDFGreen open space is one of the most important land uses, especially in densely populated urban areas. Public Green Open Land in each area regulated in Law No. 1 of 2007 is at least 20%. Based on data from the Department of Creative Works, Land and Spatial Planning as well as the Environment Agency of DKI Jakarta, West Jakarta's Green open space asset area is 277.45 Ha of the total area of West Jakarta, which is 12543 Ha. There is a need for a study to determine the potential land for green open space in West Jakarta to catch up on the fulfillment of public green open space based on spatial and regional analysis. One of the GIS-based methods that can be used to determine potential green open space is the decision tree method. This method uses AHP analysis in its formulation based on experts in the relevant agencies. In total there are 8 parameters that influence in determining potential green open space in West Jakarta, namely flood risk, air quality, population, distance to roads, distance to water sources, building density and distance to green open space assets. The modeling results are divided into five classes ranging from very priority to not priority. The total area of land that is much prioritized to be used as green open space is 95.57 hectares spread out. The modeling results show that there are still potential lands to be used as green open spaces in West Jakarta