Displaying publications 41 - 60 of 118 in total

Abstract:
Sort:
  1. Oyedele DT, Sah SA, Kairuddinand L, Wan Ibrahim WM
    Trop Life Sci Res, 2015 Dec;26(2):27-44.
    PMID: 26868708 MyJurnal
    Studies of habitat suitability (HS) are essential when animals' habitats have been altered or when animals migrate to a habitat different from their natural habitat. This study assessed HS and used an integrated geographic information system in the assessment of Rattus norvegicus in a highly developed urban environment. Using data from the Campbell market and the police quarters of George Town, Malaysia, home range (through the use of 100% Minimum Convex Polygon [MCP], 95% MCP and 95% Harmonic Mean [HM]) was estimated. Home range for male rats at Campbell market reached an asymptote, with a slight increase, at 96 radio fixes (home range = 133.52 m(2); core area = 29.39 m(2)). Female rats reached an asymptote at 62 radio fixes (home range = 13.38 m(2); core area = 9.17 m(2)). At Campbell market, male rats emerged at 1900 hours every day, whereas females emerged at 2000 hours; at police quarters, the most common time of emergence for males was 2000 hours and for females was 2200. Raster charts of R. norvegicus showed that rat hot spots can be grouped into 4 zones (market, shop houses, settlement and general places). The standardised raster chart isolated the market as the major rallying points of the rats (hot spots) by producing the highest rats frequencies of 255. All of the habitat suitability thresholds, including the built-up points, skip bins, water source and nature of the site explored in this study, produced a structural pattern (monotonic increase or decrease) of habitat suitability.
    Matched MeSH terms: Geographic Information Systems
  2. Suhaida Aini, Alias Mohd Sood, Salman Saaban
    MyJurnal
    Geographic Information System (GIS) and remote sensing are geospatial technologies that have been used for many years in environmental studies, including gathering and analysing of information on the physical parameters of wildlife habitats and modelling of habitat assessments. The home range estimation provided in a GIS environment offers a viable method of quantifying habitat use and facilitating a better understanding of species and habitat relationships. This study used remote sensing, GIS and Analytic Hierarchy Process (AHP) application tools as methods to assess the habitat parameters preference of Asian elephant. Satellite images and topographical maps were used for the environmental and topographical habitat parameter generation encompassing land use-land cover (LULC), Normalized Digital Vegetation Index (NDVI), water sources, Digital Elevation Model (DEM), slope and aspect. The kernel home range was determined using elephant distribution data from satellite tracking, which were then analysed using habitat parameters to investigate any possible relationship. Subsequently, the frequency of the utilization distribution of elephants was further analysed using spatial and geostatistical analyses. This was followed by the use of AHP for identifying habitat preference, selection of significant habitat parameters and classification of criterion. The habitats occupied by the elephants showed that the conservation of these animals would require good management practices within and outside of protected areas so as to ensure the level of suitability of the habitat, particularly in translocation areas.
    Matched MeSH terms: Geographic Information Systems
  3. Suhartono Nurdin, Muzzneena Ahmad Mustapha, Tukimat Lihan, Mazlan Abd Ghaffar
    Sains Malaysiana, 2015;44:225-232.
    Analysis of relationship between sea surface temperature (SST) and Chlorophyll-a (chl-a) improves our understanding on the variability and productivity of the marine environment, which is important for exploring fishery resources. Monthly level 3 and daily level 1 images of Moderate Resolution Imaging Spectroradiometer Satellite (MODIS) derived SST and chl-a from July 2002 to June 2011 around the archipelagic waters of Spermonde Indonesia were used to investigate the relationship between SST and chl-a and to forecast the potential fishing ground of Rastrelliger kanagurta. The results indicated that there was positive correlation between SST and chl-a (R=0.3, p<0.05). Positive correlation was also found between SST and chl-a with the catch of R. kanagurta (R=0.7, p<0.05). The potential fishing grounds of R. kanagurta were found located along the coast (at accuracy of 76.9%). This study indicated that, with the integration of remote sensing technology, statistical modeling and geographic information systems (GIS) technique were able to determine the relationship between SST and chl-a and also able to forecast aggregation of R. kanagurta. This may contribute in decision making and reducing search hunting time and cost in fishing activities.
    Matched MeSH terms: Geographic Information Systems
  4. Azimah Abd Rahman
    Sains Malaysiana, 2015;44:1229-1239.
    Kedatangan spesies burung hijrah ke Hutan Paya Laut Matang, Perak merupakan suatu fenomena unik dan amat berpotensi untuk dikomersialkan. Namun begitu sejak sepuluh tahun kebelakangan ini kedatangan spesies burung hijrah ke kawasan ini mencatatkan penurunan yang membimbangkan. Pembangunan di sekitar kawasan Hutan Paya Laut Matang dikenal pasti menjadi faktor utama penurunan ini. Selain itu, pengurusan dan pemantauan terhadap spesies burung hijrah yang tidak bersistematik juga menyumbang kepada permasalahan ini. Kaedah pengurusan dan pemantauan burung hijrah secara konvensional masih diamalkan oleh Jabatan Hidupan Liar dan Taman Negara (PERHILITAN) dalam merekod data dan maklumat yang diperoleh. Oleh itu kajian ini dilakukan dengan memperkenalkan pendekatan teknologi Sistem Maklumat Geografi (GIS) dan Penderiaan Jauh sebagai aplikasi utama yang dapat membantu dalam memperbaiki pengurusan dan pemantauan burung hijrah. Aplikasi GIS digunakan dalam memetakan data parameter kajian yang diperoleh menggunakan perisian yang bersesuaian iaitu ArcGIS 10.1 dan Penderiaan Jauh digunakan untuk memodelkan parameter kajian menggunakan aplikasi dalam perisian ERDAS Imagine 8.5. Sebanyak enam parameter kajian digunakan dalam kajian ini iaitu suhu, taburan hujan, makanan, ketinggian, gunatanah dan liputan tanah. Pemodelan setiap parameter kajian ini membolehkan kesan setiap parameter kajian terhadap taburan burung hijrah dalam suatu kawasan ditunjukkan dalam bentuk pemetaan. Hasil pemodelan ini juga membolehkan parameter yang terpenting dan paling mempengaruhi taburan burung hijrah bagi kawasan Hutan Paya Laut Matang dikenal pasti. Maklumat ini membolehkan DWNP lebih memahami keperluan burung hijrah dalam pemilihan habitat mereka. Selain itu, hasil pemodelan ini membantu DWNP dalam mengatur strategi pelaksanaan program pemeliharaan dan pemuliharaan di kawasan sekitar Hutan Paya Laut Matang bagi memastikan kedatangan spesies burung hijrah secara berterusan.
    Matched MeSH terms: Geographic Information Systems
  5. Yang SR, Yeh YL
    Sains Malaysiana, 2015;44:1677-1683.
    Countering the dangers associated the present extreme climate not only requires continuous improvement of local disaster
    prevention engineering infrastructure but also needs an enhanced understanding of the causes of the disasters. This study
    investigates the geologic hazard risk of 53 slopeland villages in Pingtung county of southern Taiwan. First, remote sensing
    (RS) techniques were utilized to interpret environmental geology and geologic hazard zonation, including dip slope, fault,
    landslide and debris flow. GIS map overlay analysis was used to further identify the extent of the geologic hazard zonation.
    As a final step, field investigation is used to comprehend geologic, topographic conditions and the geologic hazard risk
    specific to each locality. Based on data analysis and field investigation results, this study successfully integrates RS, GIS
    and GPS techniques to construct a geologic hazard risk assessment method of slopeland village. The results of this study
    can be used to promote support for future disaster prevention and disaster mitigation efforts.
    Matched MeSH terms: Geographic Information Systems
  6. Kzar AA, Mat Jafri MZ, Mutter KN, Syahreza S
    PMID: 26729148 DOI: 10.3390/ijerph13010092
    Decreasing water pollution is a big problem in coastal waters. Coastal health of ecosystems can be affected by high concentrations of suspended sediment. In this work, a Modified Hopfield Neural Network Algorithm (MHNNA) was used with remote sensing imagery to classify the total suspended solids (TSS) concentrations in the waters of coastal Langkawi Island, Malaysia. The adopted remote sensing image is the Advanced Land Observation Satellite (ALOS) image acquired on 18 January 2010. Our modification allows the Hopfield neural network to convert and classify color satellite images. The samples were collected from the study area simultaneously with the acquiring of satellite imagery. The sample locations were determined using a handheld global positioning system (GPS). The TSS concentration measurements were conducted in a lab and used for validation (real data), classification, and accuracy assessments. Mapping was achieved by using the MHNNA to classify the concentrations according to their reflectance values in band 1, band 2, and band 3. The TSS map was color-coded for visual interpretation. The efficiency of the proposed algorithm was investigated by dividing the validation data into two groups. The first group was used as source samples for supervisor classification via the MHNNA. The second group was used to test the MHNNA efficiency. After mapping, the locations of the second group in the produced classes were detected. Next, the correlation coefficient (R) and root mean square error (RMSE) were calculated between the two groups, according to their corresponding locations in the classes. The MHNNA exhibited a higher R (0.977) and lower RMSE (2.887). In addition, we test the MHNNA with noise, where it proves its accuracy with noisy images over a range of noise levels. All results have been compared with a minimum distance classifier (Min-Dis). Therefore, TSS mapping of polluted water in the coastal Langkawi Island, Malaysia can be performed using the adopted MHNNA with remote sensing techniques (as based on ALOS images).
    Matched MeSH terms: Geographic Information Systems
  7. Garba NN, Ramli AT, Saleh MA, Sanusi SM, Gabdo HT
    Isotopes Environ Health Stud, 2016 Jun;52(3):214-8.
    PMID: 26540360 DOI: 10.1080/10256016.2016.1095189
    Measurements of the environmental terrestrial gamma radiation dose rate (TGRD) in each district of Kelantan state, Malaysia, were carried out using a portable hand-held radiation survey meter and global positioning system. The measurements were done based on geology and soil types of the area. The mean TGRD was found to be 209 nGy h(-1). Few areas of relatively enhanced activity were observed in Pasir Mas, Tanah Merah and Jeli districts, which have a mean TGRD between 300 and 500 nGy h(-1). An isodose map of the area was produced using ArcGIS software version 9.3.
    Matched MeSH terms: Geographic Information Systems
  8. Gabdo HT, Ramli AT, Saleh MA, Garba NN, Sanusi M
    Isotopes Environ Health Stud, 2016 Jun;52(3):298-308.
    PMID: 26999725 DOI: 10.1080/10256016.2016.1128428
    This study was aimed at providing the baseline data of terrestrial gamma dose rates and natural radioactivity to assess the corresponding health risk in the ambient environment of the Pahang State. Terrestrial gamma radiation (TGR) from 640 locations was measured with the mean value found to be 176 ± 5 nGy h(-1). Ninety-eight soil samples were analysed using a high-purity germanium detector (HPGe), and the mean concentrations of the radionuclides (226)Ra, (232)Th and (40)K are 110 ± 3, 151 ± 5 and 542 ± 51 Bq kg(-1), respectively.(226)Ra and (232)Th concentrations were found to be three times the world average, while that of (40)K is quite higher than the world average value. The acid-intrusive geological formation has the highest mean concentrations for (226)Ra (215 ± 6 Bq kg(-1)), (232)Th (384 ± 12 Bq kg(-1)) and (40)K (1564 ± 153 Bq kg(-1)). The radium equivalent activities (Req) and the external hazard index (Hex) for the various soil types were also calculated. Some of the soil types were found to have values exceeding the internationally recommended levels of 370 Bq kg(-1) and the unity value, respectively.
    Matched MeSH terms: Geographic Information Systems
  9. Abousaeidi M, Fauzi R, Muhamad R
    Saudi J Biol Sci, 2016 Sep;23(5):555-64.
    PMID: 27579003 DOI: 10.1016/j.sjbs.2015.06.004
    This study involves the adoption of the Geographic Information System (GIS) modeling approach to determine the quickest routes for fresh vegetable delivery. During transport, fresh vegetables mainly deteriorate on account of temperature and delivery time. Nonetheless, little attention has been directed to transportation issues in most areas within Kuala Lumpur. In addition, perishable food normally has a short shelf life, thus timely delivery significantly affects delivery costs. Therefore, selecting efficient routes would consequently reduce the total transportation costs. The regression model is applied in this study to determine the parameters that affect route selection with respect to the fastest delivery of fresh vegetables. For the purpose of this research, ArcGIS software with network analyst extension is adopted to solve the problem of complex networks. The final output of this research is a map of quickest routes with the best delivery times based on all variables. The variables tested from regression analysis are the most effective parameters to make the flow of road networks slower. The objective is to improve the delivery services by achieving the least drive time. The main findings of this research are that Land use such as residential area and population as variables are the effective parameters on drive time.
    Matched MeSH terms: Geographic Information Systems
  10. Abousaeidi M, Fauzi R, Muhamad R
    J Environ Biol, 2016 09;37(5 Spec No):1167-1176.
    PMID: 29989749
    Perishable products must be transported quickly from its production area to the markets due to the climatic conditions of Malaysia. Deterioration of fresh produce is affected by temperature and delivery time. The cost to achieve such timely delivery of perishable food can affect the revenue of suppliers and retailers. Choosing an efficient delivery route at right time can reduce the total transportation cost. However, insufficient attention has been given to transportation issues with regards to fresh food delivery of greater Kuala Lumpur. The present study involves adoption of the Geographic Information System (GIS) modelling approach to determine the fastest delivery routes for fresh products to several hypermarkets. For this purpose, ArcGIS software was adopted for solving the problem of a complex road networks. With a goal of realizing the shortest time for delivery route planning, impedance function would be integrated by taking into account the time emphasized in the study. The main findings of this study include determination of efficient routes for delivery of fresh vegetables based on minimal drive time. It has been proposed that the fastest route model for delivery of fresh products is based on comparing two time frames within a day. The final output of this research was a map of quickest routes with best delivery time based on two time frames.
    Matched MeSH terms: Geographic Information Systems*
  11. Suif Z, Fleifle A, Yoshimura C, Saavedra O
    Sci Total Environ, 2016 Oct 15;568:933-945.
    PMID: 27338846 DOI: 10.1016/j.scitotenv.2015.12.134
    Understanding of the distribution patterns of sediment erosion, concentration and transport in river basins is critically important as sediment plays a major role in river basin hydrophysical and ecological processes. In this study, we proposed an integrated framework for the assessment of sediment dynamics, including soil erosion (SE), suspended sediment load (SSL) and suspended sediment concentration (SSC), and applied this framework to the Mekong River Basin. The Revised Universal Soil Loss Equation (RUSLE) model was adopted with a geographic information system to assess SE and was coupled with a sediment accumulation and a routing scheme to simulate SSL. This framework also analyzed Landsat imagery captured between 1987 and 2000 together with ground observations to interpolate spatio-temporal patterns of SSC. The simulated SSL results from 1987 to 2000 showed the relative root mean square error of 41% and coefficient of determination (R(2)) of 0.89. The polynomial relationship of the near infrared exoatmospheric reflectance and the band 4 wavelength (760-900nm) to the observed SSC at 9 sites demonstrated the good agreement (overall relative RMSE=5.2%, R(2)=0.87). The result found that the severe SE occurs in the upper (China and Lao PDR) and lower (western part of Vietnam) regions. The SSC in the rainy season (June-November) showed increasing and decreasing trends longitudinally in the upper (China and Lao PDR) and lower regions (Cambodia), respectively, while the longitudinal profile of SSL showed a fluctuating trend along the river in the early rainy season. Overall, the results described the unique spatio-temporal patterns of SE, SSL and SSC in the Mekong River Basin. Thus, the proposed integrated framework is useful for elucidating complex process of sediment generation and transport in the land and river systems of large river basins.
    Matched MeSH terms: Geographic Information Systems
  12. Khormi HM, Kumar L
    Geospat Health, 2016 11 21;11(3):416.
    PMID: 27903054 DOI: 10.4081/gh.2016.416
    We used the Model for Interdisciplinary Research on Climate-H climate model with the A2 Special Report on Emissions Scenarios for the years 2050 and 2100 and CLIMEX software for projections to illustrate the potential impact of climate change on the spatial distributions of malaria in China, India, Indochina, Indonesia, and The Philippines based on climate variables such as temperature, moisture, heat, cold and dryness. The model was calibrated using data from several knowledge domains, including geographical distribution records. The areas in which malaria has currently been detected are consistent with those showing high values of the ecoclimatic index in the CLIMEX model. The match between prediction and reality was found to be high. More than 90% of the observed malaria distribution points were associated with the currently known suitable climate conditions. Climate suitability for malaria is projected to decrease in India, southern Myanmar, southern Thailand, eastern Borneo, and the region bordering Cambodia, Malaysia and the Indonesian islands, while it is expected to increase in southern and south-eastern China and Taiwan. The climatic models for Anopheles mosquitoes presented here should be useful for malaria control, monitoring, and management, particularly considering these future climate scenarios.
    Matched MeSH terms: Geographic Information Systems
  13. Noor Shaila Sarmin, Mohd Hasmadi Ismail
    MyJurnal
    The aim of this paper is to review the potentialities and major methodological challenges
    of integrating remote sensing (RS) and geographic information system (GIS) with socioeconomic data
    from published articles or book chapters. RS and GIS combined with social science (SS)(termed as
    geoinformation technology) serve many applications for sustainable management and monitoring of
    the environment. This combined approach gives more accurate results than the single one. It makes
    information available about the trend and pattern of land use and land cover change (LUCC) with
    socioeconomic variables like population, demographic or income. This combined study which links
    RS and GIS with socioeconomic data can also be used successfully for monitoring transmission rate
    of disease and mapping or preparing vulnerability index. For impact assessment and modelling, this
    combined technology provides better results than the single one. There are some methodological
    problems for the researchers to link completely two different disciplines as the object of study and
    observational unit is completely different. However, this interdisciplinary study is gaining popularity
    day by day to researchers from different disciplines as well as decision makers.
    Matched MeSH terms: Geographic Information Systems
  14. Nur Hakimah Asnawi, Lam KC
    Sains Malaysiana, 2016;45:1869-1877.
    Penyelidikan ini dijalankan untuk mengesan perubahan guna tanah dan litupan bumi (LULC) di daerah Gombak, Selangor melalui pendekatan penderiaan jauh. Perbandingan data siri masa antara tahun 1989-1999, 1999-2014 dan 1989-2014 telah dilakukan bagi melihat perubahan LULC. Data yang digunakan ialah imej satelit Landsat (TM dan OLI-TIRS) dan Peta Guna Tanah Selangor 1990 terbitan Jabatan Pertanian Malaysia. Guna tanah dibahagikan kepada lima kategori utama, iaitu badan air, hutan, getah, kelapa sawit dan tepu bina. Penilaian ketepatan antara LULC hasil daripada pengelasan imej penderiaan jauh dengan peta guna tanah 1990 dikira berdasarkan Koeffisien Kappa menerusi teknik ralat matrik dan nilai ketepatan adalah 74.5%. Analisis GIS ke atas imej pasca klasifikasi menunjukkan perubahan sebenar LULC bagi tahun perbandingan 1989-1999 ialah 13.69%, seterusnya meningkat kepada 18.65% bagi tahun 1999-2014 dan terus meningkat bagi tahun bandingan 1989-2014, iaitu 24.25%. Guna tanah getah mengalami perubahan sebenar paling tinggi berbanding guna tanah lain dengan -47.73% bagi tahun bandingan 1989-1999, manakala tahun bandingan 1999-2014 menunjukkan guna tanah tepu bina mengalami perubahan paling tinggi dengan +44.53% dan pada tahun 1989-2014 pula guna tanah getah mengalami perubahan sebenar paling tinggi sebanyak -34.6%. Kemerosotan guna tanah getah sangat ketara di daerah Gombak dan mempunyai kaitan dengan peningkatan kawasan guna tanah tepu bina. Secara umumnya, pola perubahan guna tanah dan litupan bumi di daerah Gombak selari dengan perkembangan dan pelaksanaan pembangunan semasa oleh pihak berkuasa.
    Matched MeSH terms: Geographic Information Systems
  15. Bathrellos GD, Skilodimou HD, Chousianitis K, Youssef AM, Pradhan B
    Sci Total Environ, 2017 Jan 01;575:119-134.
    PMID: 27736696 DOI: 10.1016/j.scitotenv.2016.10.025
    Preparation of natural hazards maps are vital and essential for urban development. The main scope of this study is to synthesize natural hazard maps in a single multi-hazard map and thus to identify suitable areas for the urban development. The study area is the drainage basin of Xerias stream (Northeastern Peloponnesus, Greece) that has frequently suffered damages from landslides, floods and earthquakes. Landslide, flood and seismic hazard assessment maps were separately generated and further combined by applying the Analytical Hierarchy Process (AHP) and utilizing a Geographical Information System (GIS) to produce a multi-hazard map. This map represents the potential suitability map for urban development in the study area and was evaluated by means of uncertainty analysis. The outcome revealed that the most suitable areas are distributed in the southern part of the study area, where the landslide, flood and seismic hazards are at low and very low level. The uncertainty analysis shows small differences on the spatial distribution of the suitability zones. The produced suitability map for urban development proves a satisfactory agreement between the suitability zones and the landslide and flood phenomena that have affected the study area. Finally, 40% of the existing urban pattern boundaries and 60% of the current road network are located within the limits of low and very low suitability zones.
    Matched MeSH terms: Geographic Information Systems
  16. Khodami S, Surif M, W O WM, Daryanabard R
    Mar Pollut Bull, 2017 Jan 15;114(1):615-622.
    PMID: 27887731 DOI: 10.1016/j.marpolbul.2016.09.038
    This study aimed to evaluate the spatial and temporal distribution of heavy metals (Cd, Cr, Cu, Co, Fe, Pb, Ni, V, and Zn) in the sediments of Bayan Lepas Free Industrial Zone of Penang, Malaysia. Ten sampling stations were selected and sediment samples were collected during low tide (2012-2013). Metals were analyzed and the spatial distribution of metals were evaluated based on GIS mapping. According to interim sediment quality guidelines (ISQG), metal contents ranged from below low level to above high level at different stations. Based on the geoaccumulation index (Igeo) of sediment, sampling stations were categorized from unpolluted to strongly polluted. The enrichment factor (EF) of metals in the sediment varied between no enrichment to extremely high enrichment. The potential ecological risk index (RI) indicated Bayan Lepas FIZ was at low risk.
    Matched MeSH terms: Geographic Information Systems
  17. Sakai N, Shirasaka J, Matsui Y, Ramli MR, Yoshida K, Ali Mohd M, et al.
    Chemosphere, 2017 Apr;172:234-241.
    PMID: 28081507 DOI: 10.1016/j.chemosphere.2016.12.139
    Five homologs (C10-C14) of linear alkylbenzene sulfonate (LAS) were quantitated in surface water collected in the Langat and Selangor River basins using liquid chromatography-tandem mass spectrometry (LC-MS/MS). A geographic information system (GIS) was used to spatially analyze the occurrence of LAS in both river basins, and the LAS contamination associated with the population was elucidated by spatial analysis at a sub-basin level. The LAS concentrations in the dissolved phase (<0.45 μm) and 4 fractions separated by particle size (<0.1 μm, 0.1-1 μm, 1-11 μm and >11 μm) were analyzed to elucidate the environmental fate of LAS in the study area. The environmental risks of the observed LAS concentration were assessed based on predicted no effect concentration (PNEC) normalized by a quantitative structure-activity relationship model. The LAS contamination mainly occurred from a few populated sub-basins, and it was correlated with the population density and ammonia nitrogen. The dissolved phase was less than 20% in high contamination sites (>1000 μg/L), whereas it was more than 60% in less contaminated sites (<100 μg/L). The environmental fate of LAS in the study area was primarily subject to the adsorption to suspended solids rather than biodegradation because the LAS homologs, particularly in longer alkyl chain lengths, were considerably absorbed to the large size fraction (>11 μm) that settled in a few hours. The observed LAS concentrations exceeded the normalized PNEC at 3 sites, and environmental risk areas and susceptible areas to the LAS contamination were spatially identified based on their catchment areas.
    Matched MeSH terms: Geographic Information Systems
  18. Mogaji KA, Lim HS
    Environ Monit Assess, 2017 Jul;189(7):321.
    PMID: 28593561 DOI: 10.1007/s10661-017-5990-7
    This study integrates the application of Dempster-Shafer-driven evidential belief function (DS-EBF) methodology with remote sensing and geographic information system techniques to analyze surface and subsurface data sets for the spatial prediction of groundwater potential in Perak Province, Malaysia. The study used additional data obtained from the records of the groundwater yield rate of approximately 28 bore well locations. The processed surface and subsurface data produced sets of groundwater potential conditioning factors (GPCFs) from which multiple surface hydrologic and subsurface hydrogeologic parameter thematic maps were generated. The bore well location inventories were partitioned randomly into a ratio of 70% (19 wells) for model training to 30% (9 wells) for model testing. Application results of the DS-EBF relationship model algorithms of the surface- and subsurface-based GPCF thematic maps and the bore well locations produced two groundwater potential prediction (GPP) maps based on surface hydrologic and subsurface hydrogeologic characteristics which established that more than 60% of the study area falling within the moderate-high groundwater potential zones and less than 35% falling within the low potential zones. The estimated uncertainty values within the range of 0 to 17% for the predicted potential zones were quantified using the uncertainty algorithm of the model. The validation results of the GPP maps using relative operating characteristic curve method yielded 80 and 68% success rates and 89 and 53% prediction rates for the subsurface hydrogeologic factor (SUHF)- and surface hydrologic factor (SHF)-based GPP maps, respectively. The study results revealed that the SUHF-based GPP map accurately delineated groundwater potential zones better than the SHF-based GPP map. However, significant information on the low degree of uncertainty of the predicted potential zones established the suitability of the two GPP maps for future development of groundwater resources in the area. The overall results proved the efficacy of the data mining model and the geospatial technology in groundwater potential mapping.
    Matched MeSH terms: Geographic Information Systems*
  19. Alshami IH, Ahmad NA, Sahibuddin S, Firdaus F
    Sensors (Basel), 2017 Aug 05;17(8).
    PMID: 28783047 DOI: 10.3390/s17081789
    The Global Positioning System demonstrates the significance of Location Based Services but it cannot be used indoors due to the lack of line of sight between satellites and receivers. Indoor Positioning Systems are needed to provide indoor Location Based Services. Wireless LAN fingerprints are one of the best choices for Indoor Positioning Systems because of their low cost, and high accuracy, however they have many drawbacks: creating radio maps is time consuming, the radio maps will become outdated with any environmental change, different mobile devices read the received signal strength (RSS) differently, and peoples' presence in LOS between access points and mobile device affects the RSS. This research proposes a new Adaptive Indoor Positioning System model (called DIPS) based on: a dynamic radio map generator, RSS certainty technique and peoples' presence effect integration for dynamic and multi-floor environments. Dynamic in our context refers to the effects of people and device heterogeneity. DIPS can achieve 98% and 92% positioning accuracy for floor and room positioning, and it achieves 1.2 m for point positioning error. RSS certainty enhanced the positioning accuracy for floor and room for different mobile devices by 11% and 9%. Then by considering the peoples' presence effect, the error is reduced by 0.2 m. In comparison with other works, DIPS achieves better positioning without extra devices.
    Matched MeSH terms: Geographic Information Systems
  20. Wong HL, Garthwaite DG, Ramwell CT, Brown CD
    Environ Sci Pollut Res Int, 2017 Dec;24(34):26444-26461.
    PMID: 28948535 DOI: 10.1007/s11356-017-0064-5
    This study investigated changes over 25 years (1987-2012) in pesticide usage in orchards in England and Wales and associated changes to exposure and risk for resident pregnant women living 100 and 1000 m downwind of treated areas. A model was developed to estimate aggregated daily exposure to pesticides via inhaled vapour and indirect dermal contact with contaminated ground, whilst risk was expressed as a hazard quotient (HQ) based on estimated exposure and the no observed (adverse) effect level for reproductive and developmental effects. Results show the largest changes occurred between 1987 and 1996 with total pesticide usage reduced by ca. 25%, exposure per unit of pesticide applied slightly increased, and a reduction in risk per unit exposure by factors of 1.3 to 3. Thereafter, there were no consistent changes in use between 1996 and 2012, with an increase in number of applications to each crop balanced by a decrease in average application rate. Exposure per unit of pesticide applied decreased consistently over this period such that values in 2012 for this metric were 48-65% of those in 1987, and there were further smaller decreases in risk per unit exposure. All aggregated hazard quotients were two to three orders of magnitude smaller than one, despite the inherent simplifications of assuming co-occurrence of exposure to all pesticides and additivity of effects. Hazard quotients at 1000 m were 5 to 16 times smaller than those at 100 m. There were clear signals of the impact of regulatory intervention in improving the fate and hazard profiles of pesticides used in orchards in England and Wales over the period investigated.
    Matched MeSH terms: Geographic Information Systems
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links