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