Indonesian Journal of Geography
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The Spatiotemporal Analysis of Dengue Fever in Purwosari District, Gunungkidul Regency, Indonesia
No full textFrom 2014 to 2016, the number of prevalence of Dengue Hemorrhagic Fever (DHF) and deaths associated with DHF in Indonesia increased. DHF fatal cases were also reported from three administrative units in the Special Region of Yogyakarta, namely Bantul Regency, Gunungkidul Regency, and Yogyakarta City. Two related deaths in Purwosari, a district in Gunungkidul, raised the status of DHF to an outbreak. This study was designed to characterize the spread pattern of DHF in its endemic areas in Purwosari District using the retrospective method, anamnesis, in-depth interviews, Geographic Information System (GIS), and environmental analysis. The kernel density estimation revealed that in 2011-2017, DHF was concentrated in four villages, namely Giriasih, Giricahyo, Giritirto, and Giripurwo. There was a correlation between DHF incidents and physical geographical features of these villages, including proximity to water sources, high vegetation density, elevation, humidity, and rainfall, which created habitats for mosquito growth. A high incidence of DHF has been observed in children (50.8%) and students (57.4%), with most cases (78.7%) showing typical symptoms of the disease. A few of the 61 cases in the district developed into dengue shock syndrome (DSS) and led to death (4.9%), mainly because the public was unable to recognize the warning signs of DHF early and had limited knowledge of required management therapy. Moreover, the preventive or precautionary measures known as the 3M-Plus were not fully implemented yet.
Assessment of Gap-Filling Interpolation Methods for Identifying Mangrove Trends at Segara Anakan in 2015 by using Landsat 8 OLI and Proba-V
No full textThe existence and services of mangrove ecosystems in Segara Anakan are threatened by changes in land use on land and global warming, which requires proper and intensive monitoring. The monitoring of mangrove and its trend over large areas can be done using multi-temporal remote sensing technology. However, remote sensing data is often contaminated by cloud cover, and its corresponding shadow resulted in missing data. This study aims to assess the performance of the existed gap-filling techniques, such as, linear, spline, stineman, data interpolation Empirical Orthogonal Function (dineof) and spatial downscaling strategy employing the Proba-V imagery in 100 m, when being used for estimating the missing data and depicting the trend in NDVI from Landsat 8 OLI by using Mann-Kendall test. Our result suggested that EOF-based interpolation gave better prediction results and more accurate in predicting longer missing data. Linear interpolation, on the other hand, was accurate to predict shorter missing data. Overall, all interpolation results can reconstruct 64 (spline) to 72 % (dineof) of missing data in NDVI with the RMSE of 0.10 (dineof) – 0.13 (spline). A consistent decreasing trend was also found from the four interpolation methods, which showed the consistency of the interpolated values when used for deriving trends with similar patterns of overall decreasing trend and magnitude of changes of -0.0095 to -0.0099 (NDVI unit) over the mangrove areas in 2015. The result demonstrated the potential ability of gap-filling methods for simulating the value of missing data and for deriving trends
Numerical Simulation of Spacecraft Charging Attributed to Ionospheric Plasma in Polar and Equatorial Environment
Get PDFThe presence of spacecraft in ionospheric plasma can change plasma properties, vice versa plasma can lead to charge buildup on spacecraft. The level of charging, through electric potential of spacecraft, initially depends on plasma density. However, simulations done on four LEO satellites, i.e. ERS 1, MIDORI, ASCA and FUSE 1, showed that charging level depends on plasma electron temperature rather than plasma density which satisfied the Boltzmann’s relation in the absence of high-energy electrons from aurora. The higher the plasma electron temperature the more spacecraft exposed to negative charging. It is assumed that plasma ions and electrons are collisionless or in Maxwellian distribution. It is found that there is no strong relation between density and charging level. Furthermore, there exists insignificant different of charging between polar and equatorial satellites. It means that the placement of satellite in polar or equatorial region, as long as the presence of auroral electrons is excluded, will suffer similar level of charging which is less than 5V (negative). Since spacecraft are exposed to negative charge, electric field generated by spacecraft potential, together with mesothermal motion effects, deflects ion trajectory into donwstream region leading to ion void region. The ion density is reduced compared to electron density, but there is no significant different of ion void feature between polar and equatorial satellites.and capacity building of beneficiaries.
Simulation of Daily Rainfall Data using Articulated Weather Generator Model for Seasonal Prediction of ENSO-Affected Zones in Indonesia
No full textSynthetic rainfall simulation using weather generator models is commonly used as a substitute at locations with incomplete or short rainfall data. It incorporates a method that can be developed into forecasts of future rainfall. This study was designed to modify a rainfall prediction system based on the principles of weather generator models and to test the validity of the modelling results. It processed the data collected from eight rain stations in zones affected by El-Nino Southern Oscillation (ENSO). A large-scale predictor, that is, SST prediction data in the Nino 3.4 region over the Pacific Ocean was used as the influencing variable in projecting rainfall for the following six months after the predefined dates. Rainfall data from weather stations and SST in 1960-2000 were analyzed to identify the effects of ENSO and build a statistical model based on the regression function. Meanwhile, the model was validated using the data from 2001 to 2007 by backtesting six months in a row. The analysis results showed that the model could simulate both low rainfall in the dry season and high one in the rainy season. Validation by the student's t-test confirmed that the six-month synthetic rain data at nearly all observed stations was homogenous. For this reason, the developed model can be potentially used as one of the season prediction systems.
Topography and structural changes of Anak Krakatau due to the December 2018 catastrophic events
No full textThe flank collapse of Anak Krakatau on 22 December 2018 caused massive topography losses that generated a devastating tsunami in Sunda Strait, which then followed by eruptions that progressively changed the topography and structure of Anak Krakatau. Here, we investigated topography and structural changes due to the December 2018 flank collapse and the following eruptions by using high resolution Digital Elevation Model (DEM) before and after the events and sentinel 1A satellite image post-flank collapsed. Results show that the volumetric losses due to the 22 December 2018 flank collapsed is ~127 x 106 m3, while the following eruptions caused ~0,8 x 106 m3 losses. Structural investigation suggests two structures that may act as failure planes. The first structure is located at the western part of volcanic edifice that associated with hydrothermal alteration and the second failure is an old crater rim which delineated an actively deform volcanic cone
Urban Forced Eviction: Experiences in the Metropolitan City of Lagos, Nigeria
Get PDFUrban poverty coupled with housing shortages have contributed to the proliferation of informal settlements and slums. This is one of the complex problems arising out of urbanization and which is piling pressure on urban authorities to use unorthodox methods (such as forced evictions) to ameliorate the situation. This paper revisits the use of forced migration in Badia East Community of Lagos city. Using the human security concept as a framework for analysis, the paper chronicles how urban forced migration is used as a tool to relocate the vulnerable urban poor by urban authorities in their bid to achieve sustainable development. Critical insight into the nature of these migrations was achieved by gathering data using the mixed approach. Finding from the study revealed rampant human abuse through the use of force during the eviction process. The paper concludes by recommending that the government should use best practices, (such as adequate government-assistance) during relocations and rehousing option explored.
Measuring Urban Form Units: Alternative for Characterizing Urban Growth Pattern in Yogyakarta Urbanized Areas
No full textYogyakarta is one of city in Indonesia which experience urban agglomeration called by Yogyakarta Urbanized Area (YUA). In this paper, identified the characters of each part of YUA by examining its urban form unit. This paper assesses the characteristics of urban forms distributed within YUA. Quantitative measurements were proposed for classifying the urban form typologies. Density, diversity, and accessibility were used to represent the urban form characteristic., the typologies are classified into three groups which are low compact, middle compact, and high compact. The result shows that the majority areas in YUA are grouped into middle compact typology where most of them are located in the city of Yogyakarta administrative area. Meanwhile, the areas, categorized as low compact typology, are in the hinterland area of Yogyakarta. High compact typology are concentrated in the centre of YUA where it has the highest activity concentration for the whole urban structure context. This study discovers that characterizing the urban growth patterns using quantitative method can distinguish urban form. At the end, this paper provides an important note about the distribution of urban form typology in the agglomeration area and, in the future, can be used to design urban policies, especially in the utilization of urban space.
Analysis of the population dynamics in the “Slavic World” with a special focus on Russia
No full textPopulation changes of the Russians and other Slavs are an important original indicator of demographic, economic, political, and cultural analysis of over 300 million Slavic inhabitants in Central, Eastern, and Southeastern Europe. The indicators are conditioned by the large number of people executed in World War I and World War II, significant economic migrations, the disintegration of the Soviet Union, Yugoslavia, and Czechoslovakia. Utilizing data from official reports, the authors proceed to analyze the demographic tendencies in order to find out the relationship between modern demographic trends and political and economic events over the past years. The results showed that economic and demographic stagnation, which favor religious and national (ethnic) ambivalence, influence the strengthening of groups ethnically isolated or religiously differentiated in the observed macroregions of Eurasia. The contemporary challenges of modern society in terms of global politics (e.g. terrorism and migrations) will be more pronounced and turbulent in these areas. For these reasons, the original data represent an important segment of the study of Slavic history, demography, and politics throughout the turbulent 20th century and the beginning of the new millennium.
High Resolution Remote Sensing Data Application to Assess Parking Space in Urban Area
No full textThe increase population in a large city such as Yogyakarta has caused an increase in the number of cars. The large number of cars created another problem of limited parking space in the city. Currently, there is a lack of a spatial approach to solve the problem of parking space. With the availability of high-resolution remote sensing data, the business area in the city can be mapped accurately. This study aims to map the business zone in Yogyakarta City and to estimate the needs of parking space for trade, service, and education centers in Yogyakarta City using remote sensing imagery. The business zone really needs a parking area because many people as producers for loading goods and consumers buy at these stores. The method used to estimate the vehicle parking space requirement is a combination of field surveys and the interpretation of remote sensing images. The field survey was used to obtain the characteristics of the visitors, and the volume of filled parking space. Meanwhile, remote sensing imagery was used to obtain spatial data of land use. The parking requirements of commercial buildings are 2.25-3.15 spaces per 100 m2, offices are 1.0-1.60 spaces per 100 m2, hotels are 0.25-0.35 spaces for each sleeping room, theaters are 0.06 spaces for every seat, hospitals are 0.60 spaces for each bed, and schools are 0.10 space for every student. This paper demonstrated the use of remote sensing to solve urban vehicle problems, and such information can be used for city planning
