Indonesian Journal of Geography
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Improving Numerical Weather Prediction of Rainfall Events Using Radar Data Assimilation
Get PDFData assimilation is one of method to improve initial atmospheric conditions data in numerical weather prediction. The assimilation of weather radar data that has quite extensive and tight data is considered to be able to improve the quality of weather prediction and analysis. This study aims to investigate the effect of assimilation of Doppler weather radar data in Weather Research Forecasting (WRF) numerical model for the prediction of heavy rain events in the Jabodetabek area with dates representing four seasons respectively on 20 February 2017, 3 April 2017, 13 June 2017, and 9 November 2017. For this purpose, the reflectivity (Z) and radial velocity (V) data from Plan Position Indicator (PPI) product and reflectivity (Z) data from Constant Altitude PPI (CAPPI) product were assimilated using WRFDA (WRF Data Assimilation) numerical model with 3DVar (The Three Dimensional Variational) system. The output of radar data assimilation and without assimilation of the numerical model of WRF is verified by spatial with GSMaP data and by point with precipitation observation data. In general, WRF radar assimilation provides a better simulation of spatial and point rain events compared to the WRF model without assimilation which is improvements of rain prediction from WRF radar data assimilation would be more visible in areas close to radar sources and not echo-blocked from fixed objects, and more visible during the rainy seaso
Integrated Framework for Identification of Polluted Zones in Coastal Areas of Thiruvallur District of Tamil Nadu (India)
No full textIn this research work, hydro-geochemical characteristics were determined from twenty groundwater samples and classified into water quality zones on the basis of the World Health Organization (WHO 2006) using inverse distance weighted interpolation technique. Groundwater samples were analyzed with respect to calcium (Ca2+), magnesium (Mg2+), sodium (Na+), HCO3, total nitrate (NO2+NO3ˉ), chloride (Cl−), sulphate (SO42−), total dissolved solids (TDS), hydrogen ion concentration (pH) and electrical conductivity (EC) were measured form groundwater samples. The water quality indices (WQI1 and NPI = WQI2) were used to categorize the water. Water Quality Index (WQI) value suggest that the 65% groundwater samples (excellent + good) are safe for drinking uses and 35% groundwater samples (very poor + poor) needs treatment before consumptive uses from WQI1. Further, NPI (WQI2), shows 40% and 60% of groundwater falls under good and poor condition respectively. The findings highlight that the groundwater of few areas requires some degree of treatment before consumptive uses
A Desktop Study to Determine Mineralization Using Lineament Density Analysis at Kulon Progo Mountains, Yogyakarta and Central Java Province, Indonesia
Get PDFA geological study was conducted in Kulon Progo and its surrounding areas (Kulon Progo and Purworejo Regency). It focused on regional geology, tectonic configuration, geodynamics and magmatism, lithology and volcanology, and mineralization. Although there has been considerable research of mineralization in the area—particularly in Kokap (Kulon Progo Regency), Bagelen (Purworejo Regency) and Gupit (Magelang Regency), the potential of precious metals has not been determined due to data limitations. The study combined qualitative and semi-quantitative methods using a desktop geologic analysis, which facilitates lithology interpretation, volcanic boundary system, and lineament density assessment. The geology of the region is composed of an ancient volcanic complex of the Old Andesite Formation formed during the Late Oligocene-Miocene, and the mineralization in Kokap, Bagelen, and Gupit is epithermal. Based on the analysis results, the mineralization occurs in the central to proximal facies of the paleo-volcano, and the system ranges from 2.2 to 3.8 km in diameter. The manual analysis of the lineament density showed that the main direction of the lineaments was SE-NW with a maximum density of 2025.9 m/km2 and an anomaly limit of >1800 m/km2. In the combined semi-automatic analysis, the maximum density was 8.3 km/km2. The target area of mineralization included four anomalous areas, namely Bagelen-Kokap, Salaman, Kaligesing, and Loano, associated with the central and proximal facies of each small paleo-volcano
Investigating Groundwater Quality in the Flood Prone Neighborhood Area in Malaysia
Get PDFThe purpose of this study is to compare the quality of groundwater during wet and dry seasons in Malaysia especially in Kuala Krai District which frequently involved in annual monsoon floods and the question whether the wells can be used during floods as well as an alternative source when there are no floods. Six sampling stations were selected using six main parameters which included DO, pH, BOD, COD, TSS and NH3N. The assessment was conducted based on the standards set by Malaysian INWQS and the classification of WQI. The results of the analysis showed that most of the water samples taken during the wet season had concentration values that did not meet the DOE standards such as the DO, BOD, and NH3N parameters. Based on the WQI classification, majority stations during the wet season were in moderately contaminated except for station T6 which was clean. On the contrary, during a dry season were found to be clean except for station T1 which was moderately contaminated
Preliminary Study of Total Suspended Solid Distribution in Coastal Ujung Pangkah Gresik Based Reflectance Value of Landsat Satellite Imagery
Get PDFTotal suspended solid (TSS) is one of the parameters that uses for detecting health in aquatic environments. The distribution of the TSS value in the water body will affect the aquatic ecosystem. In this research will be analyzed the distribution value of TSS during 5 year period by utilizing Landsat 8 satellite image data, where the developed method is extraction of reflectance value from Landsat 8 satellite image for 5 years using SEADASS and then compiled the TSS algorithm with reflectance value that already obtained on the existing conditions, the algorithm obtained is estimated over 5 years back to get a picture of change and distribution of TSS value. As a case study , the coast of Ujung Pangkah Gresik was taken which has the mouth of the river Bengawan Solo. The results obtained from this study illustrate the decrease of TSS value during that time period, so that with this decrease can be concluded that at the point of field coordinate, TSS value was decreasing and causing the erosion in the environment
The Effect of Baseline Component Correlation on the Design of GNSS Network Configuration for Sermo Reservoir Deformation Monitoring
Get PDFThe condition of the geological structure in the surrounding Sermo reservoir shows that there is a fault crossing the reservoir. Deformation monitoring of that fault has been carried out by conducting GNSS campaigns at 15 monitoring stations simultaneously. However, those campaigns were not well designed. With such a design, it took many instruments and spent much money. For the next GNSS campaign, it should be designed so that the optimal network configuration is obtained and the cost can be reduced. In the design of deformation monitoring network, sensitivity criteria become very important for detecting the deformations. In GNSS relative positioning, the baseline components are correlated, but this correlation is often ignored. This research examined the effect of baseline component correlations on the design results of the GNSS configuration of the Sermo Fault network based on sensitivity criterion. In this case, the western side of the fault was taken as a reference, while the other side as an object moving relatively against the western side. This study found that the baseline component correlation affects the results of GNSS network configuration. Considering the correlation could result a sensitive network configuration with a fewer baseline; therefore, the cost and time of field surveys can be reduced. It can be said that the baseline component correlation needs to be taken into account in the configuration design of deformation monitoring network
Towards a Global View on Suburban Gentrification: From Redevelopment to Development
Get PDFThe gentrification literature, which is originated in the urban context, has now extended to suburb. Using content analysis on previous related case studies, this article shows that suburban gentrification is not necessarily a natural phenomenon resulting from disinvestment as the neighborhood lifecycle approach commonly suggests. As long as there is a development trigger, the suburb can gentrify anytime as it generally has a lower land value and a lower risk than urban area. The private sector and government play a key role in initiating and facilitating it to happen. In suburban context, the impacts of gentrification is complex, entailing varying negative and positive implications for the physical environment, the economies, and the society
Groundwater Vulnerability from Sea Water Intrusion in Coastal Area Cilacap, Indonesia
Get PDFThe important issue relating to water resources is sea water intrusion (SWI) phenomena. Nowadays, the phenomena has become serious problem in the urban coastal area. Groundwater as main sources for domestic usage cannot be used again because of its salinity.Cilacap as one of urban coastal area also face the problem. In 1977 SWIwas detectedand experienced significant developmentsin 1996,This research was conducted to: (1) analyze agroundwater vulnerability to the SWI; (2) determine adistance and adepth theinterface; and (3) analyze relationship of the groundwater vulnerability to the interface depth.It was performed an analysis of the groundwater vulnerability to the SWI using the method of GALDIT, whereas the distance and depth of the interface was determined using the method of DupuitGhyben-Herzberg. The linkage analysis of the groundwater vulnerability to the depth of the actual interface was conducted by quantitative descriptively.The results showed that the distance from the shoreline was the most determined factor of the groundwater vulnerability to the SWI, the closer to the shoreline the more swallow the depth of the interface. It existed the relevance between the vulnerability level of groundwater to the SWI with the depth of actual interface. The regions with low level of vulnerability had deep interface depth, whereas the regions with moderate level of vulnerability had swallow interface depth. Nevertheless, the SWI has not yet affected the groundwater in people wells because of its depth that was not yet exceeded of 25 m.so that this depth can be used as a reference in digging wells in the research area+
Building Information Modeling (BIM) Utilization for 3D Fiscal Cadastre
Get PDFParcels data in Indonesia are still stored in 2-dimensional (2D) geometry which are integrated with other attribute data, such as the case with the Directorate of Land and Building Tax Indonesia. Whereas, building taxes assessment refers to a number of details that require the information to be stored in 3-dimensional (3D) forms. This study aims at the use of Building Information Modeling (BIM) technology, which widely used in building asset management in 3D. This research illustrates the usability of the role of BIM in assessing and managing building taxes in Indonesia. The point clouds were obtained using Terrestrial Laser Scanner (TLS) technology. The point clouds processed so that it can form 3-dimensional geometrical apartment. The attributes of the 3-dimensional model integrated with the geometric model using the BIM concept. The results analyzed to assess whether BIM concept was able to fulfill the needs of the 3D fiscal cadastre in Indonesia