Cross section method of contouring Aug 22, 2015 · It covers key map elements like the title, scale, legend, and contours. Method of Cross-Section In this method cross-sectional points are taken at regular interval. They are marked on drawing sheets and then contours are interpolated. Mar 25, 2020 · Cross-Section Method: In the cross-section method of indirect contouring, suitably spaced sections are duly set out from the traverse lines such as the centre line of roads, railways etc and then the observations are made on the different points of each section generally with the help of a theodolite. Procedure This video lecture is suitable for Students of Civil Engineering as well as for the aspirants who wish to brush up on their basics. Oct 6, 2013 · Contours never cross except at cliffs. CROSS – SECTION METHOD In this method also a selected lien cross – sectional readings are taken at regular interval. By Cross- Sections: This method is most suitable for the surveys of long narrow strips such as a road, railway or canal etc. In this method, cross-sectional points are selected at regular intervals. By levelling the reduced level of all those points are established. The grid size may vary from 5 m x 5 m to 25 m x 25 m depending upon the nature of the terrain, the contour interval required and the scale of the map desired. (ii) By Cross-Sections : This method is most suitable for survey of long narrow strips such as a road, railway canal etc. It is of two types; Direct Method; Indirect Method; Indirect contouring of the spacing of cross-section depends upon as follows Apr 9, 2023 · Two lines with different heights don’t meet or cross each other. Cross Section method Jul 11, 2023 · Methods of Contouring. e for route surveys. Apr 15, 2024 · (i) From cross-sections (ii) From spot levels and (iii) From contours. The cross-section lines need not necessarily be at right angles to the contour lines are drawn by interpolation [Ref. Commonly used size of square varies from 5 m 5 m to 20 m 20 m. Direct Method of Contouring 1. 2. But the contours seem to cross each other in the case of a cliff that hangs over or a cave that goes into a hill. The steps involved are as follows: Sep 23, 2024 · In the cross-section method, cross sections are established perpendicular to the central line of the area being surveyed. You can either hand draw it to match your requirements or draw in CAD. Cross -section ore run transverse lo the centre line of the work and representative points are marked along the lines of cross-section. Characteristics 4. By usual leveling procedure reduced levels of all selected points on cross sections are found. Indirect points marked and contour lines interpolated. (2) Method of Cross-section: In this method cross-sectional points are taken at regular interval. This method involves drawing a cross section of the site and estimating the Dec 22, 2024 · II. (a) Method of squares, (b) Method of cross-section, or (c) Radial line method. 3. Contouring . It is generally used in plain terrain. Computation of Volume from Cross-sections Sep 11, 2022 · Contouring is used for site selection, canal alignment, determining ground conditions, and reservoir/earthwork capacity. B. Tacheometric Method: Tacheometric Jan 15, 2020 · This method is very suitable for a small open area where contours are required at a lose vertical interval. Contour lines are subsequently interpolated between these marked points. Cross section method is most suitable for preparing contour maps for road works, rail works, canals etc. Contouring is the connection of points of equal value to form lines. Figure 2 shows a typical planning of this work. Sep 6, 2017 · The spreadsheet included with this article includes formulae which have automated the process of calculating section areas using the trapezoidal rule. The indirect method of contour surveying using the cross sections method is a technique used to estimate the elevation of intermediate points along a cross section of the site. Squares or Grid method. consider X, Y, Z as the centre line of the road or railway or canal as shown in fig. Contours show elevations and can reveal landforms. Second method is useful for finding earth work in foundations of large building and the last method is useful for finding capacity of reservoirs. Direct Method of the Contouring. This method is more accurate than the indirect methods as the points are directly located on the contour and this method is suitable for area of small extent. By cross-section-This method is suitable for road, railway and canal survey. Jul 26, 2023 · Method of Cross-Section. Methods 5. Interpolation 6. First method is useful for computing earth work involved in road/rail/canal/sewage works. This is also suitable for large-scale mapping. The following are the indirect methods are commonly used for locating contours. This means every point on a contour line has the same The contours are then drawn by a process called interpolation of contours from the levels of the guide points. This can save a great deal of time if you are using the cross section method. 7 shows a typical planning of this work. Direct methods contour small, controlled areas by radial lines or large oblong areas by pegs. Characteristics of contours are described, like indicating slopes, hills, depressions, ridges and valleys. The spacing between these cross sections depends on factors such as the contour interval, the scale of the plan, and the nature of the terrain. Cross-sections help visualize terrain in 2D. Indirect method of contouring in cross section’s method. In this method cross-sectional points are taken at regular interval. Levels of all grid points are established by levelling. Square method or grid method. This method is suitable for road, railway and canal survey i. The reduced level of different selected points is located and joined to form a contour. Draw your cross section lines. Cross sections are run transverse to the centre line of the work and representative points are marked along the lines of cross-section. Cross-Section Method: In the cross-section method of indirect contouring, suitably spaced sections are duly set out from the traverse lines such as the centre line of roads, railways etc and then the observations are made on the different points of each section generally with the help of a theodolite. The accuracy of the cross section method depends to a large degree on the distance you choose to set between the The method fallow in the indirect method of contouring is. 1]. The points are marked on the drawing sheets, their reduced levels (RL) are marked and contour lines interpolated. Levelling is performed to determine the reduced levels of these points. Method of Cross-Sections : In this method a transit traverse is run. Contour surveying can be broadly classified into two primary methods: the Direct Method and the Indirect Method. C. 1. Definition of Contour 2. A. Nov 21, 2015 · It focuses on explaining the indirect grid or square method, cross section method, tachometric method, and radial lines method in detail. Aug 4, 2024 · b. The document teaches how to identify features like valleys, ridges, and hills based on contour patterns and recommends drawing cross-sections to confirm interpretations. In this method, cross-sections perpendicular to the counter line of the area is set out. Methods of Contour Surveying. Cross section method. Tacheometric Method: Jun 28, 2015 · Explanation. the cross section is set at every 10m on the centre line whereas the other dimension to complete a rectangle may be 5m. Direct method; Indirect method; Direct Method: In this method the contour to be plotted is actually on the ground by locating the points of that elevation. This method is accurate but very tedious and slow. Aug 23, 2015 · Contouring is used for site selection, canal alignment, determining ground conditions, and reservoir/earthwork capacity. Contour Interval and Horizontal Equivalent 3. Apr 15, 2024 · Method of Cross-section: In this method cross-sectional points are taken at regular interval. B) By cross-section method: This method is suitable for preparing a contour map of a road, railway or canal alignment. Fig. Direct and indirect contouring methods involve taking level readings and plotting points to interpolate contour lines. Figure 17. 2 Jan 29, 2018 · Direct Method. Methods of The Contouring. Typically, this type of land has a very long strip but narrow width. Indirect methods use cross-sections along base lines or divide areas into squares to plot Oct 28, 2021 · Uses of indirect method of contouring: Cross section method: This method is suitable for route survey, when cross sections are taken transverse to the longitudinal section. Direct and indirect contouring methods are outlined, including spot levels, cross sections, and tacheometry. For each method, it provides an example to illustrate the procedure, including taking spot levels, determining reduced levels, and interpolating contour lines either by estimation or arithmetical calculation. There are mainly Two methods of the locating contours. The points are then marked on the drawing sheets, and their reduced levels (RL) are indicated. Each method has its own set of procedures, instruments, and suitability depending on the project’s requirements and the terrain’s complexity. Apr 17, 2023 · Cross Sections Method. In this method, we draw a grid point on the ground and measure the reduce level of all these points. Definition of Contour: A contour or a contour line may be defined as the line of intersection of a level surface with the surface of ground. Indirect Method of the Contouring. The photo opposite shows 4cm is the equivalent to 20m on the plan. 1). Drawing the Contour Lines. Method of Squares: In this method area is divided into a number of squares and all grid points are marked (Ref. Then grid square is Squares or Grid method; Cross section method; Square or grid method: In this method, the area to be surveyed is divided into a grid or series of squares. Square or grid method: The method is used for large scale mapping and at average precision. Cross section method Procedure: After reading this article you will learn about:- 1. . The cross-section lines need not necessarily be at right angles to the centre line of Mar 25, 2021 · You need to know the scale to calculate the length of you cross section, the distance between them and the distances along the cross section where the elevation changes. Square or grid method: In this method, the area to be surveyed is divided into a grid or series of squares. c. fhg xwcsq sybfyy hrhjf tjfo ybix unfmv rwcern rhbii ggbal diuek dwchj oglsn wmmkhax yyn