Ragab Khalil | King AbdulAziz University (KAU) Jeddah, Saudi Arabia (original) (raw)
Papers by Ragab Khalil
JES. Journal of Engineering Sciences
Flash flood in urban area strikes mainly the road network. In fact, the streets during flood act ... more Flash flood in urban area strikes mainly the road network. In fact, the streets during flood act as streams or overland flow paths. This jams the traffic, stops the public services, and interrupts the economic activities. Previous studies have treated floods in urban areas as if they were occurring in rural areas. This study presents a new approach that treats the road network as the path of the flash flood water. The new approach uses a 3D city model as the basis for hydrology analysis. This approach regards the building and the streets as part of the terrain that results in water flowing through the streets as it does in reality. The depth of flood water in the streets is calculated and used as a risk factor. Remote Sensing (RS) and Geographical Information System (GIS) technologies are used to obtain and prepare the required input data for the hydraulic model. Various flood scenarios were investigated for different return periods and flood risk code maps for the road network were generated. The obtained results showed that 41.2% of the road network in the study area is under high flood risk from fairly frequent rainfall events, and this percentage reaches 80% to 90% for low frequent flood events (50 years and 100 years flood). The new approach was evaluated by comparing the derived results with actual flood data and had an accuracy of 77%. The results of this study may help decision makers to take the necessary actions to protect people and property.
This book is a collections of my researches, in which I presented a new laboratory calibration me... more This book is a collections of my researches, in which I presented a new laboratory calibration method for Electronic Distance Measurement instruments (EDM), study the accuracy of contour maps generation, solving circular curve problems with direct method and present three new cases in the circular curve solution , check the accuracy of digital compass and enlargement of sighting distance of the digital level.
saudigis.org
Suitability analysis is performed to identify sites suitable for a specific purpose so that plann... more Suitability analysis is performed to identify sites suitable for a specific purpose so that planning and management decisions can be made in a site-specific manner. Land suitability analysis is similar to choosing an appropriate location and mapping a suitability ...
The close-range photogrammetry has a wide use in measuring the three dimensions of the objects. T... more The close-range photogrammetry has a wide use in measuring the three dimensions of the objects. This needs to have at least two photos for the object and for certain cases multiimages of the object may be needed. Single image has been used for measuring some dimensions of the objects, but the measurements must be in a plan (two dimensions) by making a rectification for the single image by using some of the ground control points. To make some three dimensions measurements from a single image, an additional condition must be found. This paper presents a new approach for three dimensions measuring system by using a mirror that lies in a position to reflect the object and appear with it in the single image. The mathematical model of this approach has been developed and tested theoretically and practically and it gave promising results. This paper will concentrate on the special case that the camera axis is horizontal and the mirror plan is vertical.
Journal of Geographic Information System, 2013
Most surveying works for mapping or GIS applications are performed with total station. Due to the... more Most surveying works for mapping or GIS applications are performed with total station. Due to the remote nature of many of the sites surveyed, the surveys are often done in unprojected, local, assumed coordinate systems. However, without the survey data projected in real world coordinates, the range of possible analyses is limited and the value of existing imagery, elevation models, and hydrologic layers cannot be exploited. This requires a transformation from the local assumed to the real world coordinate systems. There are various built-in and add-in tools to perform transformations through GIS programs. This paper studies the effect of using Georeferencing tool, Spatial Adjustment tool (Affine and similarity) and CHaMP tool on the precision and relative accuracy of total station survey. This transformation requires real-world coordinates of at least two control points, which can be collected from different sources. This paper also studies the effect of using geodetic GPS, hand-held GPS, Google Earth (GE) and Bing Basemaps as sources for control points on the precision and relative accuracy of total station survey. These effects have been tested by using 111 points covered area of 60,000 m 2 and the results have shown that the CHaMP tool is the best for preserving the relative accuracy of the transformed points. The Georeferencing and spatial adjustment (similarity) tools give the same results and their accuracy are between 1/1000 and 1/300 depending on the source of control points. The results have also shown that the cornerstone to preserve the precision and relative accuracy of the transformed coordinates is the relative position of the control points despite their source.
The horizontal circular curve can be described by seven elements: (1) Radius of the curve; (2)def... more The horizontal circular curve can be described by seven elements: (1) Radius of the curve; (2)deflection angle between tangents; (3) tangent distance; (4) external distance; (5) middle ordinate; (6) long chord; and (7) length of the curve. When the radius and deflection angle are given, the other five curve elements can be directly computed. In some practical problems, the radius and the deflection angle are unknown; two other elements must be known to solve the problem. Seven cases must be solved depending on the known curve elements, as mentioned by other authors. This paper present three other cases and a direct method is proposed for two cases of the earlier seven.
ABSTRACT Tunnel alignment or selecting a suitable tunnel route is an important task in civil engi... more ABSTRACT Tunnel alignment or selecting a suitable tunnel route is an important task in civil engineering and urban planning. Lots of information and considerations such as the Decision support system for Tunnel alignment based on GIS Ragab Khalil Civil Engineering Research Magazine, vol (35), No (2), 2013, pp 656-667 locations of tunnel portals, maximum grade, soil type and the interactions with the surrounding landscape and urban features must be taken into account when dealing with such this problem. Traditionally, selecting tunnel route done on maps or CAD environment, in which it is difficult to represent all the effected parameters and deal with them at the same time. Geographic Information System (GIS) can represent the different geographical features of the real world by related data layers and play a key role in integrating different kinds of information. The aim of this paper is to explain how GIS technology can be used to understand geographical constraints and manage information efficiently to select the tunnel route, and the benefits this approach brought to such this project. In this approach, surface, landscape and urban features, geology and other parameters are represented in several layers. Spatial and 3D analyst modules are used for the processing of the data to determine the suitable location of the tunnel route. The proposed approach elevates the alignment process from traditional methods to multi-criteria decision analysis (MCDA) method
6! % 7 ! 4' % () #) % !) ' @ , ! ; , ,'( ,A &, % ( )! B() CNewton- Raphson method ... more 6! % 7 ! 4' % () #) % !) ' @ , ! ; , ,'( ,A &, % ( )! B() CNewton- Raphson method and iteration methods % )
Currently, Global Positioning System (GPS) techniques are becoming a much larger part of the surv... more Currently, Global Positioning System (GPS) techniques are becoming a much larger part of the surveying industry. Many companies are now using GPS in their everyday work activities. The Real Time Kinematic (RTK) positioning is an integral part of topographic surveys, road surveying, con-structions and most civil engineering applications. Normally, RTK can be used to collect the posi-tioning data successfully and quickly. The civil and construction projects are designed in ground distances while RTK measurements are done in grid coordinate system, in which the distances between points are different from ground. The RTK measurements should be converted to ground for compatibility with the designed. In this paper, the accuracy of three alternatives for converting RTK measurements to ground was studied. These alternatives are, using scale factor, using two ground reference points and using Low Distortion Projection (LDP) surface. For the accuracy in-vestigation purpose, a traverse of 14 ...
Reflectorless total station (RLTS) has made it possible for only one person to carry out field me... more Reflectorless total station (RLTS) has made it possible for only one person to carry out field measurements and inaccessible points can be measured with relative ease. There is no sufficient information about the accuracy of these instruments for the long range measurements. This paper attempts to evaluate the accuracy of reflectorless distance measurements ranging up to 1000 m and to determine the surface area needed for such measurements at different incidence angles. An experiment was carried out to examine what effect surface material, target size and incidence angle had on distance measurement. In this experiment 10 different distances were measured using targets of 6 different materials and 4 different sizes at 5 different incidence angles. To properly evaluate the results, a special supporting base was designed and manufactured for holding the reflecting targets to ensure accuracy in the evaluation. Based on the accuracy analysis of a lot of testing results, the conclusions t...
SUMMARY The digital leveling technique which is a combination of automatic levels and automatic r... more SUMMARY The digital leveling technique which is a combination of automatic levels and automatic reading and booking is commonly applied in precise leveling nowadays. The sighting distance used in line leveling is usually 50 m, and maximum 90 m. The longer sightings are needed in some applications such as crossing valleys and water areas and some times in road and rail surveying. In this paper SOKKIA Digital Level SDL30 was used to investigate the enlargement of the sighting distance up to 600 m. The key factor in this investigation is magnification the bar code scale of the rod. The bar code was magnified by 2, 4 and 6 times the original scale. The leveling performed by using the new bar codes is compared to that performed using the bar code of normal size. Trigonometric leveling using the total station is also performed and the results were compared. The results show that the Sokkia digital level SDL30 can process the bar code readings at a maximum sighting distance of 400 m with b...
SUMMARY The trapezoidal rule and Simpson’s rule are numerical approximation methods to be used to... more SUMMARY The trapezoidal rule and Simpson’s rule are numerical approximation methods to be used to approximate the area under a curve. The area is divided into (n) equal pieces, called a subinterval or trapezoid. Each subinterval is approximated as a trapezoid considering the outer edge as straight line in the trapezoidal rule. In Simpson’s rule, each two subintervals approximated as a trapezoid and a parabola. This paper provides two techniques as trails to improve the area calculated using Simpson’s rule and trapezoidal rule. The first proposed technique deals with the curved part as a circular segment instead of parabola in Simpson’s rule. The second technique add or subtract a small parabola to the calculated area when using trapezoidal rule. The proposed techniques were applied on several numerical examples of known area and the results were compared.
Volume estimation of borrow pits is common application in civil Engineering. Several methods for ... more Volume estimation of borrow pits is common application in civil Engineering. Several methods for volume estimation have been presented in literature. In general, they rely on a specific polynomial to fit the surface heights. Practically, each site’s topography is unique and may not follow that polynomial. In this paper, regression analysis to find the most suitable equation that fit each site is presented. Using numerical examples, results from the proposed approach are presented and accuracy compared with existing methods.
International journal of Geomatics and Geosciences, 2014
Urban green spaces are quite significant in reducing negative effects of urbanization. They are v... more Urban green spaces are quite significant in reducing negative effects of urbanization. They are viewed as the green lung of the city, and typically perform important functions, including absorbing rainwater and pollutants, and mitigating urban heat. Urban green spaces can also provide considerable socioeconomic benefits, such reducing work-related stress, and increasing property values. Green space is becoming an important measure in judging the ecological sustainability of urban areas. Planners and designers need efficient tools to quantitatively evaluate and compare the impact of alternative plans and designs so that more informed development choices could be made. This study presents an evaluation of spatial equity in distribution of green spaces in Jeddah city using Geographic Information System (GIS). GIS analysis is used to study the spatial distribution of needs and accessibility. The results of this study show that the average green space per capita is 0.9 m 2 and more that ...
Journal of Geographic Information System, 2017
Flash floods in arid environments are a major hazard feature to human and to the infrastructure. ... more Flash floods in arid environments are a major hazard feature to human and to the infrastructure. Shortage of accurate environmental data is main reason for inaccurate prediction of flash flooding characteristics. The curve number (CN) is a hydrologic number used to describe the storm water runoff potential for drainage area. This study introduces an approach to determine runoff coefficient in Jeddah, Saudi Arabia using remote sensing and GIS. Remote sensing and geographic information system techniques were used to obtain and prepare input data for hydrologic model. The land cover map was derived using maximum likelihood classification of a SPOT image. The soil properties (texture and permeability) were derived using the soil maps published my ministry of water and agriculture in Saudi Arabia. These soil parameters were used to classify the soil map into hydrological soil groups (HSG). Using the derived information within the hydrological modelling system, the runoff depth was predicted for an assumed severe storm scenario. The advantages of the proposed approach are simplicity, less input data, one software used for all steps, and its ability to be applied for any site. The results show that the runoff depth is directly proportional to runoff coefficient and the total volume of runoff is more than 136 million cubic meters for a rainfall of 103.6 mm.
Abstract Suitability analysis is performed to identify sites suitable for a specific purpose so t... more Abstract Suitability analysis is performed to identify sites suitable for a specific purpose so that planning and management decisions can be made in a site-specific manner. Land suitability analysis is similar to choosing an appropriate location and mapping a suitability ...
Routine check of EDM instruments is increasingly important. Finding of a suitable testing area, l... more Routine check of EDM instruments is increasingly important. Finding of a suitable testing area, legal access to such areas, time of carrying out the instruments and the costs of permanent installation are problems facing the field calibration. The limited space is main problem facing the laboratory testing of EDM instruments. Some researchers stated that distances between 5 and 100 meters should be measured to test the EDM, so some reflectors have to be mounted outside the laboratory which causes a big change in the atmospheric conditions along the measured distance. This paper presents a new compact, laboratory method for verification of the accuracy of distance measuring using EDM and total station. This new method complies with the stringent space of the laboratories and no need to mount reflectors outside the laboratory. The mathematical model of this method has been developed and tested theoretically and practically and it gave promising results. The precision of the new method...
The Digital Elevation Model (DEM) is an important part of mapping technology. It is used for seve... more The Digital Elevation Model (DEM) is an important part of mapping technology. It is used for several purposes including contours derivation, geometric correction of photogrammetric and remote sensing images and Geographic Information System (GIS) applications. There are different procedures and techniques for collecting the data to generate DEMs. These techniques include digitizing contour maps, direct field observations using ground surveying methods, photogrammetric and remote sensing procedures and recently by Global Positioning System (GPS) and laser profiling and laser scanning. Interpolation is often required to create DEM from sparse number of points. In this paper the interpolation accuracy of four methods namely: 1) Inverse distance to a power, 2) Kriging, 3) Radial basis function and 4) Triangulation with linear interpolation are investigated. The investigation was practically performed using GPS and Total Station observations of the same test area for comparative purposes...
The horizontal circular curve can be described by seven elements:(1) Radius of the curve;(2) defl... more The horizontal circular curve can be described by seven elements:(1) Radius of the curve;(2) deflection angle between tangents;(3) tangent distance;(4) external distance;(5) middle ordinate;(6) long chord; and (7) length of the curve. When the radius and deflection angle ...
JES. Journal of Engineering Sciences
Flash flood in urban area strikes mainly the road network. In fact, the streets during flood act ... more Flash flood in urban area strikes mainly the road network. In fact, the streets during flood act as streams or overland flow paths. This jams the traffic, stops the public services, and interrupts the economic activities. Previous studies have treated floods in urban areas as if they were occurring in rural areas. This study presents a new approach that treats the road network as the path of the flash flood water. The new approach uses a 3D city model as the basis for hydrology analysis. This approach regards the building and the streets as part of the terrain that results in water flowing through the streets as it does in reality. The depth of flood water in the streets is calculated and used as a risk factor. Remote Sensing (RS) and Geographical Information System (GIS) technologies are used to obtain and prepare the required input data for the hydraulic model. Various flood scenarios were investigated for different return periods and flood risk code maps for the road network were generated. The obtained results showed that 41.2% of the road network in the study area is under high flood risk from fairly frequent rainfall events, and this percentage reaches 80% to 90% for low frequent flood events (50 years and 100 years flood). The new approach was evaluated by comparing the derived results with actual flood data and had an accuracy of 77%. The results of this study may help decision makers to take the necessary actions to protect people and property.
This book is a collections of my researches, in which I presented a new laboratory calibration me... more This book is a collections of my researches, in which I presented a new laboratory calibration method for Electronic Distance Measurement instruments (EDM), study the accuracy of contour maps generation, solving circular curve problems with direct method and present three new cases in the circular curve solution , check the accuracy of digital compass and enlargement of sighting distance of the digital level.
saudigis.org
Suitability analysis is performed to identify sites suitable for a specific purpose so that plann... more Suitability analysis is performed to identify sites suitable for a specific purpose so that planning and management decisions can be made in a site-specific manner. Land suitability analysis is similar to choosing an appropriate location and mapping a suitability ...
The close-range photogrammetry has a wide use in measuring the three dimensions of the objects. T... more The close-range photogrammetry has a wide use in measuring the three dimensions of the objects. This needs to have at least two photos for the object and for certain cases multiimages of the object may be needed. Single image has been used for measuring some dimensions of the objects, but the measurements must be in a plan (two dimensions) by making a rectification for the single image by using some of the ground control points. To make some three dimensions measurements from a single image, an additional condition must be found. This paper presents a new approach for three dimensions measuring system by using a mirror that lies in a position to reflect the object and appear with it in the single image. The mathematical model of this approach has been developed and tested theoretically and practically and it gave promising results. This paper will concentrate on the special case that the camera axis is horizontal and the mirror plan is vertical.
Journal of Geographic Information System, 2013
Most surveying works for mapping or GIS applications are performed with total station. Due to the... more Most surveying works for mapping or GIS applications are performed with total station. Due to the remote nature of many of the sites surveyed, the surveys are often done in unprojected, local, assumed coordinate systems. However, without the survey data projected in real world coordinates, the range of possible analyses is limited and the value of existing imagery, elevation models, and hydrologic layers cannot be exploited. This requires a transformation from the local assumed to the real world coordinate systems. There are various built-in and add-in tools to perform transformations through GIS programs. This paper studies the effect of using Georeferencing tool, Spatial Adjustment tool (Affine and similarity) and CHaMP tool on the precision and relative accuracy of total station survey. This transformation requires real-world coordinates of at least two control points, which can be collected from different sources. This paper also studies the effect of using geodetic GPS, hand-held GPS, Google Earth (GE) and Bing Basemaps as sources for control points on the precision and relative accuracy of total station survey. These effects have been tested by using 111 points covered area of 60,000 m 2 and the results have shown that the CHaMP tool is the best for preserving the relative accuracy of the transformed points. The Georeferencing and spatial adjustment (similarity) tools give the same results and their accuracy are between 1/1000 and 1/300 depending on the source of control points. The results have also shown that the cornerstone to preserve the precision and relative accuracy of the transformed coordinates is the relative position of the control points despite their source.
The horizontal circular curve can be described by seven elements: (1) Radius of the curve; (2)def... more The horizontal circular curve can be described by seven elements: (1) Radius of the curve; (2)deflection angle between tangents; (3) tangent distance; (4) external distance; (5) middle ordinate; (6) long chord; and (7) length of the curve. When the radius and deflection angle are given, the other five curve elements can be directly computed. In some practical problems, the radius and the deflection angle are unknown; two other elements must be known to solve the problem. Seven cases must be solved depending on the known curve elements, as mentioned by other authors. This paper present three other cases and a direct method is proposed for two cases of the earlier seven.
ABSTRACT Tunnel alignment or selecting a suitable tunnel route is an important task in civil engi... more ABSTRACT Tunnel alignment or selecting a suitable tunnel route is an important task in civil engineering and urban planning. Lots of information and considerations such as the Decision support system for Tunnel alignment based on GIS Ragab Khalil Civil Engineering Research Magazine, vol (35), No (2), 2013, pp 656-667 locations of tunnel portals, maximum grade, soil type and the interactions with the surrounding landscape and urban features must be taken into account when dealing with such this problem. Traditionally, selecting tunnel route done on maps or CAD environment, in which it is difficult to represent all the effected parameters and deal with them at the same time. Geographic Information System (GIS) can represent the different geographical features of the real world by related data layers and play a key role in integrating different kinds of information. The aim of this paper is to explain how GIS technology can be used to understand geographical constraints and manage information efficiently to select the tunnel route, and the benefits this approach brought to such this project. In this approach, surface, landscape and urban features, geology and other parameters are represented in several layers. Spatial and 3D analyst modules are used for the processing of the data to determine the suitable location of the tunnel route. The proposed approach elevates the alignment process from traditional methods to multi-criteria decision analysis (MCDA) method
6! % 7 ! 4' % () #) % !) ' @ , ! ; , ,'( ,A &, % ( )! B() CNewton- Raphson method ... more 6! % 7 ! 4' % () #) % !) ' @ , ! ; , ,'( ,A &, % ( )! B() CNewton- Raphson method and iteration methods % )
Currently, Global Positioning System (GPS) techniques are becoming a much larger part of the surv... more Currently, Global Positioning System (GPS) techniques are becoming a much larger part of the surveying industry. Many companies are now using GPS in their everyday work activities. The Real Time Kinematic (RTK) positioning is an integral part of topographic surveys, road surveying, con-structions and most civil engineering applications. Normally, RTK can be used to collect the posi-tioning data successfully and quickly. The civil and construction projects are designed in ground distances while RTK measurements are done in grid coordinate system, in which the distances between points are different from ground. The RTK measurements should be converted to ground for compatibility with the designed. In this paper, the accuracy of three alternatives for converting RTK measurements to ground was studied. These alternatives are, using scale factor, using two ground reference points and using Low Distortion Projection (LDP) surface. For the accuracy in-vestigation purpose, a traverse of 14 ...
Reflectorless total station (RLTS) has made it possible for only one person to carry out field me... more Reflectorless total station (RLTS) has made it possible for only one person to carry out field measurements and inaccessible points can be measured with relative ease. There is no sufficient information about the accuracy of these instruments for the long range measurements. This paper attempts to evaluate the accuracy of reflectorless distance measurements ranging up to 1000 m and to determine the surface area needed for such measurements at different incidence angles. An experiment was carried out to examine what effect surface material, target size and incidence angle had on distance measurement. In this experiment 10 different distances were measured using targets of 6 different materials and 4 different sizes at 5 different incidence angles. To properly evaluate the results, a special supporting base was designed and manufactured for holding the reflecting targets to ensure accuracy in the evaluation. Based on the accuracy analysis of a lot of testing results, the conclusions t...
SUMMARY The digital leveling technique which is a combination of automatic levels and automatic r... more SUMMARY The digital leveling technique which is a combination of automatic levels and automatic reading and booking is commonly applied in precise leveling nowadays. The sighting distance used in line leveling is usually 50 m, and maximum 90 m. The longer sightings are needed in some applications such as crossing valleys and water areas and some times in road and rail surveying. In this paper SOKKIA Digital Level SDL30 was used to investigate the enlargement of the sighting distance up to 600 m. The key factor in this investigation is magnification the bar code scale of the rod. The bar code was magnified by 2, 4 and 6 times the original scale. The leveling performed by using the new bar codes is compared to that performed using the bar code of normal size. Trigonometric leveling using the total station is also performed and the results were compared. The results show that the Sokkia digital level SDL30 can process the bar code readings at a maximum sighting distance of 400 m with b...
SUMMARY The trapezoidal rule and Simpson’s rule are numerical approximation methods to be used to... more SUMMARY The trapezoidal rule and Simpson’s rule are numerical approximation methods to be used to approximate the area under a curve. The area is divided into (n) equal pieces, called a subinterval or trapezoid. Each subinterval is approximated as a trapezoid considering the outer edge as straight line in the trapezoidal rule. In Simpson’s rule, each two subintervals approximated as a trapezoid and a parabola. This paper provides two techniques as trails to improve the area calculated using Simpson’s rule and trapezoidal rule. The first proposed technique deals with the curved part as a circular segment instead of parabola in Simpson’s rule. The second technique add or subtract a small parabola to the calculated area when using trapezoidal rule. The proposed techniques were applied on several numerical examples of known area and the results were compared.
Volume estimation of borrow pits is common application in civil Engineering. Several methods for ... more Volume estimation of borrow pits is common application in civil Engineering. Several methods for volume estimation have been presented in literature. In general, they rely on a specific polynomial to fit the surface heights. Practically, each site’s topography is unique and may not follow that polynomial. In this paper, regression analysis to find the most suitable equation that fit each site is presented. Using numerical examples, results from the proposed approach are presented and accuracy compared with existing methods.
International journal of Geomatics and Geosciences, 2014
Urban green spaces are quite significant in reducing negative effects of urbanization. They are v... more Urban green spaces are quite significant in reducing negative effects of urbanization. They are viewed as the green lung of the city, and typically perform important functions, including absorbing rainwater and pollutants, and mitigating urban heat. Urban green spaces can also provide considerable socioeconomic benefits, such reducing work-related stress, and increasing property values. Green space is becoming an important measure in judging the ecological sustainability of urban areas. Planners and designers need efficient tools to quantitatively evaluate and compare the impact of alternative plans and designs so that more informed development choices could be made. This study presents an evaluation of spatial equity in distribution of green spaces in Jeddah city using Geographic Information System (GIS). GIS analysis is used to study the spatial distribution of needs and accessibility. The results of this study show that the average green space per capita is 0.9 m 2 and more that ...
Journal of Geographic Information System, 2017
Flash floods in arid environments are a major hazard feature to human and to the infrastructure. ... more Flash floods in arid environments are a major hazard feature to human and to the infrastructure. Shortage of accurate environmental data is main reason for inaccurate prediction of flash flooding characteristics. The curve number (CN) is a hydrologic number used to describe the storm water runoff potential for drainage area. This study introduces an approach to determine runoff coefficient in Jeddah, Saudi Arabia using remote sensing and GIS. Remote sensing and geographic information system techniques were used to obtain and prepare input data for hydrologic model. The land cover map was derived using maximum likelihood classification of a SPOT image. The soil properties (texture and permeability) were derived using the soil maps published my ministry of water and agriculture in Saudi Arabia. These soil parameters were used to classify the soil map into hydrological soil groups (HSG). Using the derived information within the hydrological modelling system, the runoff depth was predicted for an assumed severe storm scenario. The advantages of the proposed approach are simplicity, less input data, one software used for all steps, and its ability to be applied for any site. The results show that the runoff depth is directly proportional to runoff coefficient and the total volume of runoff is more than 136 million cubic meters for a rainfall of 103.6 mm.
Abstract Suitability analysis is performed to identify sites suitable for a specific purpose so t... more Abstract Suitability analysis is performed to identify sites suitable for a specific purpose so that planning and management decisions can be made in a site-specific manner. Land suitability analysis is similar to choosing an appropriate location and mapping a suitability ...
Routine check of EDM instruments is increasingly important. Finding of a suitable testing area, l... more Routine check of EDM instruments is increasingly important. Finding of a suitable testing area, legal access to such areas, time of carrying out the instruments and the costs of permanent installation are problems facing the field calibration. The limited space is main problem facing the laboratory testing of EDM instruments. Some researchers stated that distances between 5 and 100 meters should be measured to test the EDM, so some reflectors have to be mounted outside the laboratory which causes a big change in the atmospheric conditions along the measured distance. This paper presents a new compact, laboratory method for verification of the accuracy of distance measuring using EDM and total station. This new method complies with the stringent space of the laboratories and no need to mount reflectors outside the laboratory. The mathematical model of this method has been developed and tested theoretically and practically and it gave promising results. The precision of the new method...
The Digital Elevation Model (DEM) is an important part of mapping technology. It is used for seve... more The Digital Elevation Model (DEM) is an important part of mapping technology. It is used for several purposes including contours derivation, geometric correction of photogrammetric and remote sensing images and Geographic Information System (GIS) applications. There are different procedures and techniques for collecting the data to generate DEMs. These techniques include digitizing contour maps, direct field observations using ground surveying methods, photogrammetric and remote sensing procedures and recently by Global Positioning System (GPS) and laser profiling and laser scanning. Interpolation is often required to create DEM from sparse number of points. In this paper the interpolation accuracy of four methods namely: 1) Inverse distance to a power, 2) Kriging, 3) Radial basis function and 4) Triangulation with linear interpolation are investigated. The investigation was practically performed using GPS and Total Station observations of the same test area for comparative purposes...
The horizontal circular curve can be described by seven elements:(1) Radius of the curve;(2) defl... more The horizontal circular curve can be described by seven elements:(1) Radius of the curve;(2) deflection angle between tangents;(3) tangent distance;(4) external distance;(5) middle ordinate;(6) long chord; and (7) length of the curve. When the radius and deflection angle ...