Geo-referencing the satellite image from Google Earth by relative and absolute positioning

Introduction of geo-visualisation tools over the internet such as Google Earth (GE) has cut down the cost of data acquisition. This study is undertaken to validate the geo-information provided by GE that could be used for geospatial work. Satellite images and latitude-longitude coordinates (X-Y) for the campus of the University of Malaya has been downloaded from the internet. Geo-referencing of the satellite image was carried out using the relative positioning (RP) and absolute positioning (AP) within the geographic information system environment. Sources of X-Y for AP were obtained from GE and a topography map provided by the Malaysian Survey and Mapping Department. For absolute positioning, the data was obtained using GPS equipment. Comparison of these sources was undetaken with the total residual mean square error (RMSE) of X-Y in the map and at the source. All sources of X-Y had produced the total RMSE within 0.00014 degree. Considering the total RMSE as standard deviation (SD), the resulting range of error for geo-referencing of the satellite image was within 15 m. Thus, it can be concluded that geo-information from GE can be used as the source of base map

Scale factor and digital elevation analysis for hydrological studies

The digital elevation model (DEM) is usually used to express a topographic surface in three dimensions and to imitate essential natural geography. The DEM is a model of the elevation surface, which is subject to errors. The Gurun area in Kedah, Malaysia was chosen for study, and the focus was on terrain analysis and the impacts of DEM resolution on topographic attributes related to hydrological studies. Five DEM resolutions were derived and the impact of different resolutions on the topographical parameters related to hydrological studies was compared. The result demonstrated that a fine DEM resolution revealed more detailed topographic values compared to the coarse DEM

The application of digital elevation model for the Klang Valley geological structure.

Purpose – The purpose of this paper is to utilise the interactive view capability of the geographical information system (GIS) for the geological interpretation in Klang Valley, Malaysia.Design/methodology/approach – Topographical map scale of 1:10 000 was used to generate digital elevation model (DEM). The geological map was draped over the DEM to create a 3D perspective view. The geological interpretation was undertaken using the 3D capability of the GIS software.Findings – From the study, five lineaments which could possibly be the newly identified faults and one lithological boundary have been delineated.Research limitations/implications – Although these findings need to be rechecked in the field, they show the capability of the DEM application in structural geology interpretation.Practical implications – The results obtained from this study demonstrate the capability of utilising a geological map draped over DEM for structural geological interpretation. Thus the technique may increase the interpretation accuracy.Originality/value – The major outcome of this research is the possible use of DEM in the application of geological study

Selection criteria using the Delphi method for siting an integrated hazardous waste disposal facility in Malaysia.

Choosing the site for an integrated hazardous waste disposal facility requires an extensive evaluation process to identify the best available disposal location. This location must comply with the requirements of governmental regulations while minimising the economic, environmental, health and social costs. In addition, the local public must be convinced that the hazardous waste disposal facility is required and that all reasonable steps will be taken to make it compatible with the environment. In addition, the location of the facility should be able to reasonably resolve larger issues. This study identifies environmental, economic and social criteria to be considered for the site selection of an integrated hazardous waste disposal facility. The Delphi method was employed in this study to gather information on the site selection criteria for siting a fully integrated hazardous waste disposal facility in Malaysia. The use of an online Delphi survey is useful and effective when both time and costs are limitations in a study, due to geographically dispersed experts. A two-round Delphi survey was employed in this study. The overall findings indicate that environmental criteria should be given priority when locating the facility, followed by the social and economic criteria

Accuracy assessment of moderate resolution image spectroradiometer products for dust storms in semiarid environment.

Dust storms are strongly and negatively associated with the annual cycle of rainfall and coincide with the west and southwesterly winds in west and south west of Iran. Accuracy assessment of particulate matter products of moderate resolution image spectroradiometer was studied in this research. Moderate resolution image spectroradiometer products consist of aerosol optical thickness, its corresponding image red, green and blue and moderate resolution image spectroradiometer/ terra calibrated radiances 5 minutes L1B swath 1 km, which shows the environmental information at terrestrial, atmospheric and ocean phenomenology. Daily aerosol optical thickness data retrieved from moderate resolution image spectroradiometer from May 2009 to May 2010 were compared with the amount of particulate matter measured at ground in Sanandaj, Iran, using non-linear correlation coefficient. Results showed that the moderate resolution image spectroradiometer image / terra calibrated radiances 5 minutes L1B swath 1 km is able to detect dust storms distribution and their blowing direction over study area clearly. The air quality conditions obtained in with dust storm period were unhealthy and correlation coefficients between moderate resolution image spectroradiometer aerosol optical thickness and particulate matter concentration in this period were higher than without dust storm period. The moderate resolution image spectroradiometer aerosol optical thickness values lower than 0.1 were acquired uncertainty level. Comparison of moderate resolution image spectroradiometer images/ terra calibrated radiances 5 minutes L1B swath 1 km and image red, green and blue showed that moderate resolution image spectroradiometer has limitation in retrieval of aerosol optical thickness from the dust storm with high concentration of particulate matter. This study reveals that the algorithm which is applied to refine the aerosol optical thickness is not able to recognize the amount of particulate matter in low and very high concentrations sensitively. No study has previously been conducted to investigate the accuracy of the moderate resolution image spectroradiometer particulate matter products

Land surface temperature assessment in semi-arid residential area of Tehran, Iran using Landsat imagery

Land cover change especially from green areas to urban areas may increase land surface temperature (LST). In this study, Landsat Enhanced Thematic Mapper Plus (ETM+) on 15 May 2000 (spring), 9 July 2000 (summer), 26 November 2000 (autumn) and 10 January 2001(winter) were utilized to study LST in Tehran, Iran. The accuracy of the LST analysis was evaluated using six year ground temperature data. The Non Linear Correlation Coefficient (NLCC) between normalized differences vegetation index (NDVI) and LST was found to be higher in the spring compared to the other seasons. The LST value in the west of the city was similar to the surrounding areas, but in north, east and south of the city were lower compared to the north, north east and east of the surrounding areas in all seasons. The gravel and sandy soil in the western part of the surrounding areas were warmer than the impervious surface area (ISA) in the city in summer. It was found that high urban density in semi arid climate with low vegetation in the surrounding areas does not increase the LST value in the city compared to its surrounding areas

PM10 monitoring using MODIS AOT and GIS, Kuala Lumpur, Malaysia.

Remote sensing has been increasingly used in retrieval Aerosol optical thickness (AOT) to particulate matter pollution monitoring. In this study, Moderate resolution image Spectroradiometer (MODIS) data were utilized in particulate matter pollution monitoring. Daily aerosol optical thickness (AOT) data retrieved from MODIS using Non-Linear Correlation Coefficient (NLCC) with polynomial equation Were compared with the amount of particulate matter PMIO measured at Three ground Air Quality Monitoring Stations (AQMS)-Victoria Kl, Cheras Kl and Gombak- in Kuala lumpur and surrounding area. The PMIO data were imported in geographical information system (GIS) environment to derive the PMIO maps in Kuala Lumpur stations. Results showed that the amounts of PMIO in dry season are higher than those in rainy season in stations. The NLCC between MODIS AOT and PMIO concentration was obtained higher in Victoria Kl compared to Gombak and Cheras Kl. GIS maps were found to show better distribution of PMIO compared to the ground station data. This study reveals AOT data from MODIS and GIS map can be utilized to study the air quality, especially distribution of PMIO in the places where there are ground measurements

Hydrological response of semi-arid river catchment to rainfall and temperature fluctuations

Determining the response of basin water resources to rainfall and temperature fluctuations is a crucial source of information for basins water resources planning and management. The study used a descriptive, Mann-Kendall trend test (M-K) and Multiple Linear Regression (MLR). The mean, standard deviations and variations were spatially interpolated using the geostatistical technique. The trend results showed an increase in both rainfall and temperature series. However, the only statistically significant trends were in June and September for rainfall series and in February, May, and April for the temperature series. Rainfall exhibited high temporal variability whereas temperature showed high spatial variability. The intra-annual variability was higher than the inter-annual variability, suggesting that the local climate is largely controlled by natural force. The result of the multiple linear regression (R2=0.431), indicates that the hydrology and water resources of the basin are impacted largely by factors not considered in this study such as land use changes, infiltration, and rate of evaporation among others. However, among the factor considered, rainfall (Beta = 0.505; P = 001) has the highest impacts on the river discharge behavior and should be given preference while addressing water resources predicaments in the catchment