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1 Chapter 1 : Topography - Wikipedia â Topographical maps are large-scale maps, they show a great deal of details about the relief. â In Topographical survey, actual survey is carried out and different methods are used to represent relief on the map as follows. Performed at large scales, these surveys are called topographical in the old sense of topography, showing a variety of elevations and landforms. As such, elevation information was of vital importance. In the United States, the national map-making function which had been shared by both the Army Corps of Engineers and the Department of the Interior migrated to the newly created United States Geological Survey in, where it has remained since. Although the project eventually foundered, it left an indexing system that remains in use. By the s, centralized printing of standardized topographic maps began to be superseded by databases of coordinates that could be used on computers by moderately skilled end users to view or print maps with arbitrary contents, coverage and scale. TIGER was developed in the s and used in the and subsequent decennial censuses. Digital elevation models DEM were also compiled, initially from topographic maps and stereographic interpretation of aerial photographs and then from satellite photography and radar data. Since all these were government projects funded with taxes and not classified for national security reasons, the datasets were in the public domain and freely usable without fees or licensing. TIGER and DEM datasets greatly facilitated Geographic information systems and made the Global Positioning System much more useful by providing context around locations given by the technology as coordinates. Initial applications were mostly professionalized forms such as innovative surveying instruments and agency-level GIS systems tended by experts. By the mids, increasingly user-friendly resources such as online mapping in two and three dimensions, integration of GPS with mobile phones and automotive navigation systems appeared. As of, the future of standardized, centrally printed topographical maps is left somewhat in doubt. For example, colors can be used to indicate a classification of roads. These signs are usually explained in the margin of the map, or on a separately published characteristic sheet. In the United States, where the primary national series is organized by a strict 7. Topographic maps conventionally show topography, or land contours, by means of contour lines. Contour lines are curves that connect contiguous points of the same altitude isohypse. These maps usually show not only the contours, but also any significant streams or other bodies of water, forest cover, built-up areas or individual buildings depending on scale, and other features and points of interest. Today, topographic maps are prepared using photogrammetric interpretation of aerial photography, lidar and other Remote sensing techniques. Older topographic maps were prepared using traditional surveying instruments. The cartographic style content and appearance of topographic maps is highly variable between national mapping organizations and aesthetic traditions and conventions persist, particularly amongst European countries at medium map scales. National Mapping Agency and Map series Although virtually the entire terrestrial surface of Earth has been mapped at scale 1: Several commercial vendors supply international topographic map series. It provides topographic maps and data to meet the needs of the sustainable development of the nation. The maps are published at scales 1: Maps can also be viewed online. It is reported that these maps are accurate and attractively printed in seven colors, and that successive editions show progressive improvement in accuracy. Maps at scales 1: Page 1

2 Chapter 2 : Icse Resource Provider: Chapter 3- Interpretation of Topographical Maps Topographical Maps These are general-use maps at medium scales that present elevation (contour lines), hydrography, geographic place names, and a variety of cultural features. Current-generation topographic maps are created from digital GIS databases, and are branded "US Topo.". These maps are helpful for nearly any outdoor activity, such as hiking, fishing, and of course â hunting. Before I begin to write about using maps and satellite imagery for my elk hunt, I thought it would be helpful to clarify how we read a topographic map, and what terrain features can be interpreted from these maps. The most common type of topographic maps are USGS 1: In addition to showing natural terrain, most topographic maps also feature symbols and markings for prominent man-made features and boundaries. Understanding Contour and Elevation Topographic maps identify terrain and elevation with the use of contour lines. A contour is a line that connects points of equal elevation. So, if you walked along any contour line on a topographic map, you would remain at the same elevation the entire time. However, if you begin to cross over contour lines, you are either gaining or losing elevation. Every fifth contour line on a topographic map is an index contour â which is a visibly thicker line with a marked elevation. It is important to look at the elevation scale of the map, which can be determined by observing the change in elevation between index contours. Finally, the spacing between contour lines determines how steep or gradual the change in elevation is in that area. For example, look at the zoomed-in map above and notice the large contour interval at the bottom of the map, compared to the very small contour interval at the top-center of the map. This is telling is that the area at the top of the map has a much steeper incline the contour lines are very close together, and the area at the bottom of the map has a relatively flatter surface the contour lines are spaced further apart. Identifying Terrain Features Use the map above to identify the corresponding terrain features belowâ A ridgeline is a primary line of high ground, often connecting peaks or hilltops, from which other terrain features originate. A saddle is most easily identified as a low spot between two hilltops or peaks, but a saddle can also just be a dip in a ridgeline. If you are in a saddle you have high ground in two opposing directions and low ground in the other two directions. A saddle can often be identified by contour lines that form an hourglass shape. A bench is a flat or at least comparatively flat area that exists on the rise of a ridge. A ridge will climb and climb, flatten out to a bench temporarily, and then will continue to climb to the ridge peak. Benches are often found mid-way up a ridge side. However, whereas a valley is typically long and parallel to a ridgeline, a draw is commonly smaller, steeper, usually perpendicular to the ridge, and is commonly created by water flow or rockfall. Hilltops and peaks can be easily identified on topographic maps by looking for contour lines that form complete, concentric circles. I have also published an article that will show you how to add topographic maps to Google Earth. If you want one map resource to show you topographic maps, public- and private-land boundaries, private land owner information, public land types federal, state, forest, BLM, etc. Their products can be used on your computer, and in the field via chips that work in hand-held GPS units. I hope that helps you have a better understanding of how you can use topographic maps for your next outdoor adventure! Please check back soon for more discussion on how we can use topographic maps and our knowledge of terrain features to help us locate and hunt the game that we are after. Page 2

3 Chapter 3 : Overview - Maps Interpretation of Topographical Maps STAGE 1 - TYPES OF MAPS There are different types of maps. We will focus now on Topographical Maps. 1. Topographical maps. Remote sensing is a general term for geodata collection at a distance from the subject area. Passive sensor methodologies[ edit ] Main articles: Aerial photography and Satellite imagery Besides their role in photogrammetry, aerial and satellite imagery can be used to identify and delineate terrain features and more general land-cover features. Certainly they have become more and more a part of geovisualization, whether maps or GIS systems. False-color and non-visible spectra imaging can also help determine the lie of the land by delineating vegetation and other land-use information more clearly. Images can be in visible colours and in other spectrum. Photogrammetry Photogrammetry is a measurement technique for which the co-ordinates of the points in 3D of an object are determined by the measurements made in two photographic images or more taken starting from different positions, usually from different passes of an aerial photography flight. In this technique, the common points are identified on each image. A line of sight or ray can be built from the camera location to the point on the object. It is the intersection of its rays triangulation which determines the relative three-dimensional position of the point. Known control points can be used to give these relative positions absolute values. More sophisticated algorithms can exploit other information on the scene known a priori for example, symmetries in certain cases allowing the rebuilding of three-dimensional co-ordinates starting from one only position of the camera. Similar techniques are applied in bathymetric surveys using sonar to determine the terrain of the ocean floor. In recent years, LIDAR LIght Detection And Ranging, a remote sensing technique that uses a laser instead of radio waves, has increasingly been employed for complex mapping needs such as charting canopies and monitoring glaciers. Forms of topographic data[ edit ] Terrain is commonly modelled either using vector triangulated irregular network or TIN or gridded Raster image mathematical models. In the most applications in environmental sciences, land surface is represented and modelled using gridded models. In civil engineering and entertainment businesses, the most representations of land surface employ some variant of TIN models. In geostatistics, land surface is commonly modelled as a combination of the two signals â the smooth spatially correlated and the rough noise signal. The DLSM can then be used to visualize terrain, drape remote sensing images, quantify ecological properties of a surface or extract land surface objects. Note that the contour data or any other sampled elevation datasets are not a DLSM. A DLSM implies that elevation is available continuously at each location in the study area, i. Digital Land Surface Models should not be confused with Digital Surface Models, which can be surfaces of the canopy, buildings and similar objects. For example, in the case of surface models produces using the lidar technology, one can have several surfaces â starting from the top of the canopy to the actual solid earth. The difference between the two surface models can then be used to derive volumetric measures height of trees etc. Raw survey data[ edit ] Topographic survey information is historically based upon the notes of surveyors. They may derive naming and cultural information from other local sources for example, boundary delineation may be derived from local cadastral mapping. While of historical interest, these field notes inherently include errors and contradictions that later stages in map production resolve. Remote sensing data[ edit ] As with field notes, remote sensing data aerial and satellite photography, for example, is raw and uninterpreted. It may contain holes due to cloud cover for example or inconsistencies due to the timing of specific image captures. Most modern topographic mapping includes a large component of remotely sensed data in its compilation process. Topographic map A map of Europe using elevation modeling In its contemporary definition, topographic mapping shows relief. The USGS calls maps based on topographic surveys, but without contours, "planimetric maps. While not officially "topographic" maps, the national surveys of other nations share many of the same features, and so they are often called "topographic maps. Digital Elevation Models, for example, have often been created not from new remote sensing data but from existing paper topographic maps. Many Page 3

4 government and private publishers use the artwork especially the contour lines from existing topographic map sheets as the basis for their own specialized or updated topographic maps. The latter is concerned with underlying structures and processes to the surface, rather than with identifiable surface features. Digital elevation modeling[ edit ]. Page 4

5 Chapter 4 : Topographic map - Wikipedia Topographic map definition, a map showing topographic features, usually by means of contour lines. See more. A method of representing relief on a map by depicting the shadows that would be cast by high ground if light were shining from a certain direction. It can be defined as the addition of shadows to give the optical illusion of a third dimension, making hills stand out in relief. The shadows can be regarded as those which would be cast on an imaginary relief model of the ground when illuminated by parallel rays of light from a selected direction or directions. In this map, it is assumed to be from north west at an angle of 45 degree with the horizon. This method too gives a general idea of relief of the country by it does not give the actual height and that it is difficult to know whether a piece of land is sloping uphill or downhill. Dendritic drainage patterns are most common. They develop on a land surface where the underlying rock is of u niform resistance to erosion. They develop where the river channel follows the slope of the terrain. TRELLIS Rectangular drainage patterns develop where linear zones of weakness, such as joints or faults cause the streams to cut down along the weak areas in the rock. The main river the consequent flows straight down hill. Each colour used on a map has significance. BLACK â All names, river banks, broken ground, dry streams, surveyed trees, heights and their numbering, railway lines, telephone and telegraph lines, lines of latitude and longitude. Surveyed trees have numbers on their trunks. They serve as landmarks and are not allowed to be cut. On a topo map, all settlements are shown by symbols in RED colour. The size of the symbol and size and style of letters used give an idea of the size of the settlement. In the case of large cities, major roads are marked and named. Deserted village cities, temporarily occupied huts are also shown. Places of worship, forts, water towers, burial grounds, police stations, post office, dak bungalow, circuit houses, etc. NOTE â Site is the land on which the settlement village or town is built. Fertile plains and wide river valleys. Swamps, marsh land, sandy deserts, thick impenetrable forests, flood-prone areas, steep mountain slopes. It may be the height of a dam, bridge, sand dune or it can be the depth of a well, tank, hill or river canal, for example, 3r, 5r, 8r, etc. Chapter 5 : Topographical Maps theinnatdunvilla.com provides ICSE Solutions for Class 10 Geography Chapter 1 Map Study: Interpretation and Topographical Maps for ICSE Board Examinations. Chapter 6 : How to Read and Interpret Topographic Maps â Sole Adventure knowledge of map features, map symbology, and principles of interpretation is needed. â Aerial photographs are used to construct topographic maps and to keep the map information up-to-date. The best. Chapter 7 : What is a Topographic Map? Geoscience Australia Topographic maps are based on topographical surveys. Performed at large scales, these surveys are called topographical in the old sense of topography, showing a variety of elevations and landforms. Chapter 8 : Topographic map Define Topographic map at theinnatdunvilla.com The most common type of topographic maps are USGS, topographic maps, also known as minute quadrangles. The USGS has produced over 55, maps that cover the entire United States in detail. Chapter 9 : What is an Elevation Map? Page 5

6 The US Geological Survey has published many different kinds of maps, including several series of topographic maps. Only a few series are in common use. The 7 1/2-minute quadrangles, which have a scale of,, are the most popular. Page 6