Pdf a design of contour generation for topographic maps. Representing heights on maps professor keith clarke contours on maps. But they are no longer drawn by cartographers, they are mostly automatically derived from. When a contour line is drawn on a map it represents a given elevation. Every point on the map touching the line should be the same elevation. Contour lines of different elevations cannot cross each other. A line drawn on a map or plan connecting points of equal elevation. Contour lines of different heights can never cross each other. Topographic mapshave a variety of uses, from planning the best route for a hike to determining a location for a school or an airport. Flat ground is indicated where the contours are widely separated and. All contour lines eventually connect with themselves. Contour lines never run into one another except in the case of a vertical cliff.
The horizontal distance between any two contour lines indicates the amount of slope and varies inversely on the amount of slope. Rule 5 contour lines are closer together in steep terrain and farther apart in flat. Draw a line between the two points bounding the desired profile area. Langbein and others abstract river floods are the result of many causes, and one of the primary objectives of scientific hydrology is the segregation and evaluation of the causative factors. Contour lines of different elevations can unite to form one line in case of a vertical cliff.
Topographic characteristics of drainage basins by walter b. Find contour lines lesson plans and teaching resources. Mark four points two on the endpoints, and two between and draw the contours. It depends upon the scale of the map, nature of the ground and. A plane surface when they are straight, parallel and equally spaced. Contours show distinct characteristic features of the terrain as follows. Farming across the slope helps to shorten slope lengths. Contour lines cannot merge or cross one another on map except in the case of an overhanging cliff. Contour lines are often given specific names beginning iso ancient greek. A contour line is a single, clean, incisive line, which defines edges. The properties used to modify a contour line object are located to the right of the screen when your contour line is selected.
They never cross, split or intersect at a cliff they might merge. Contours may pass through small, tightly grouped hydrographic features, such as sewage lagoons. On some maps, numbers on the lines will let you know what the elevation is for that line. The distance between contour lines indicates the steepness of the slope. Divide 300 feet by 3 to get one contour every 100 feet. It is, however, unlike outline, which only states the outside edge of an object defining difference between positive and negative space. Sep 29, 2017 contour lines, isolines, or isograms are used widely in different fields such as meteorology, geology, oceanography, and other sciences to represent lines with equal values of a certain attribute. Predictions are based on measurements from nearby locations or time periods.
The methods section includes information about the individual methods. Flat ground is indicated where the contours are widely separated and steepslope where they run close together. Readingunderstanding topographic maps school of forest. Imaginary line joining points of equal elevation above or below a datum contour lines have a specific contour interval interval is the vertical distance between contours ci is a. Each drawing below violates a rule of contour lines. There is even an animation that gives students practice. Contour lines close together indicates a steep slope. Contour farming, the practice of tilling sloped land along lines of consistent elevation in order to conserve rainwater and to reduce soil losses from surface erosion. The method of characteristics provides a technique for properly designing the contour of a supersonic nozzle for shock free, isentropic flow, taking into account the multidimensional flow inside the duct the purpose of. A point on a map or chart that has the elevation noted. On contour lines the level of lines is also written. On a map the contour lines will be spaced closer together with a decline in height above sealevel. Concave slope a slope which becomes progressively steeper uphill. From each mark, indicate the vertical height with a dot on a scale.
All points along the same contour line are at the same elevation. Find animations helping students interpret hachured lines, contour spacing, and valleyridge placement. A contour line represents an imaginary line on the ground, above or below sea level. The diagram illustrates how contour lines show relief by joining points of equal elevation. Start with contour farming as a farmer, your first step for slowing down rainwater is to determine your fields contour lines. Evenly spaced contour lines indicate a uniform slope. A contour or a contour line may be defined as the line of intersection of a level surface with the surface of ground. Below is a description of each available property in the order that.
Contour lines do not cross each other, divide or split. Pdf contour lines generation in karstic plateaus for. All points in a contour line have the same elevation. Characteristics of contours x contour lines 50 never run into one 40 another except in 30 the case of a 20 vertical cliff. Hachures are short lines perpendicular to the contour line.
A contour line of a function of two variables is a curve along which the function has a constant. Contour lines characteristics of contour lines are. Features of contour lines are helpful in plotting and interpretation of several features in the map. The geospatial work flow section provides support in selecting methods for di. Characteristics of contours i all points in a contour line have the same elevation.
So two different contour lines cannot intersect or otherwise contact each other except at a point where a vertical or overhanging surface, such as a vertical or overhanging face of a cliff, exists. Contour lines cannot merge or cross one another on map except in the case of an overhanging cliff 9. The change in elevation between one contour line and the next. These properties can either be adjusted right before adding the contour line to your landscape or after it has been added. This section describes the characteristics of interpolation methods in general. Aug 23, 20 contour contour is an imaginary line on ground joining points of equal or constant elevations. Contour lines are the most common method of showing relief and elevation on a standard topographic map. There are many fields of interest in which contour analysis and visualization can be applied.
All points on a contour line have the same elevation. The closer together the lines are, the steeper the slope. In a depression, the contour lines also form circles. In economics, contour lines can be used to describe features which vary.
The objectives of contour analysis and visualization can be described in the following stages 1. Contour lines, sometimes called level lines, join points of equal elevation. Use contour lines to determine elevations of mountains and. In this case, several contours coincide and the horizontal equivalent becomes zero. So two different contour lines cannot intersect or otherwise contact each other except at a point where a vertical or overhanging surface, such as a vertical or overhanging face of a cliff, exists on the ground figure 818 shows an overhanging cliff. Contour lines are a key features of topographic maps as they make the comprehension of terrain more easy. Contour elevation numbers indicate the direction of elevation by always reading pointing uphill. However, contour lines of different elevation intersect only in case of an overhanging cliff. The physical characteristics of line the physical characteristics of line are many. They can be smooth or flowing, short or choppy, dark or light, broad or narrow. This allows you to do all the land preparation, planting, and harvesting across the slope. This allows you to do all the land preparation, planting, and harvesting across the.
Vertical distance between any two consecutive contours is known as the contour interval. Contour lines connect a series of points of equal elevation and are used to illustrate topography, or relief, on a map. All points on the contour line are at the same elevation. The greater the distance between two contours the less the slope. It is, essentially, the outline or silhouette of a given object or figure. Basin characteristics from hydrological processes at the point scale to hydrological processes throughout the space continuum. Compared with straightline planting, the practice reduces fertilizer loss and increases crop yields on uneven terrain. Contour lines, isolines, or isograms are used widely in different fields such as meteorology, geology, oceanography, and other sciences to represent lines with equal values of a certain attribute.
The principal characteristics of contour lines which help in plotting or reading a contour map are as follows. Contour lines must close, not necessarily in the limits of the plan. On a map the contour lines will be spaced closer with an increase in height above sealevel. Every contour closes on itself either within or beyond the limits of the map. The closer together the contour lines appear on a topographic map, the steeper the slope assuming constant contour intervals. Visualize the contour lines in 3 dimensional view application. In the world of art, a contour line is a line which defines a form or an edge. So two different contour lines cannot intersect or otherwise contact each other except at a point where a vertical or overhanging surface, such as a vertical or overhanging face of a cliff, exists on the. Topographic survey topographic survey the most common method of representing the topography of an area is to use contour lines contours a contour lineis an imaginary level line that connects points of equal elevation topographic survey there are several rules to note when viewing topographic maps. Contour lines can indicate the outer borders of the foot and suggest a threedimensional form. Changing contours indicates a change of ground form. Lines may be short or long, thin or thick, straight or curved, direct or meandering, zigzag or serpentine, distinct or blurred. Regression methodology for bivariate heteroscedastic data pdf.
Characteristics of contour lines, contouring, assignment help. Pdf contour lines are a key features of topographic maps as they make the comprehension of terrain more easy. If it closes beyond the limits of the map it will run to the map edge. Contour lines contour line interpolation free 30day. Contour lines isolinesand imaginary line in the map. Specific names are most common in meteorology, where multiple maps with different variables may be viewed simultaneously. Characteristics of contour lines a contour line is a line of equal elevation. A uniform slope is indicated when the contour lines are uniformly spaced and 4. Contouringtopographic map preparation,uses and characteristics. Then plant your crops across the slope or on the contour. Following are the characteristics of contour lines in surveying for reading contour maps.
Contour line contour is a slow, intense inspection of parts. The following are general characteristics of contour lines. Contour lines types, characteristics and uses in surveying. The contour lines in an area are drawn keeping difference in elevation of between two consecutive lines constant. Contouring contouring contour definitions, objectives, contour interval, horizontal equivalent, uses and characteristics of contour lines, methods of plotting contours, direct and indirect methods of contouring, contour gradient.
Contour contour is an imaginary line on ground joining points of equal or constant elevations. In cartography, contour lines are an imaginary line of a terrain that joins the point of equal elevation above a given level, such as mean sea level or benchmark. All elevation values and the resulting contour lines were cast. Design of a supersonic nozzle using method of characteristics. Natural physical features topographical features of the site thru contour map site drainage existing natural features of trees size, type, diameter, height, spread of roots. Closed contours with arrow in the centre represent depressions.
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