Degree grid on the map and its elements

The degree grid is formed by meridians and parallels. Meridians are lines that are drawn on the globe through the North and South Poles. Through every point on earth's surface you can draw a meridian. All meridians on the globe have same length. The shadow formed by the noon gnomon is the direction of your area, that is, the local meridian. The length of part of the meridian is equal to an arc of 1 ° and is almost 11 km.

Parallels-cola on the surface of the globe; all points of one parallel are equidistant from the equator. The lengths of the parallels are different: they increase when approaching the equator and decrease towards the poles. All points on the same meridian have the same longitude, but different latitudes. All points of the same parallel, on the contrary, have the same latitude, but different longitude.

The largest parallel is the equator. This circle is on the surface of the globe, all points of which depend on both poles at unequal distances.

The image of a degree grid on a plane, that is, on a map, is called a cartographic grid.

Meridians and parallels are depicted differently on maps. For example, on a world map the meridians are straight, parallel friend friend, parallels are straight lines perpendicular to the meridians. On the map of the hemispheres, only the middle meridian of each hemisphere and the equator are depicted with straight lines, and other meridians and parallels are depicted with curved lines.

Geographic latitude and longitude

The location of any point on the globe is determined using geographic coordinates: latitude and longitude.

Geographic latitude - the distance along the meridian in degrees from the equator to any point globe. The equator is taken as the origin of latitude - zero parallel. Latitudes are calculated along the meridian from 0° to 90° on both sides of the equator and are called northern or southern accordingly. On maps, parallels are inscribed on the side frames, and on the globe - at 0° and 180° of the meridian.

Geographic longitude is the distance along the parallel in degrees from the prime meridian to any point on the globe. The Greenwich prime meridian, which passes near London, is taken as the starting point for longitude. Longitudes to the east of the prime meridian, from 0° to 180°, are called eastern, to the west - western; are considered in parallel.

Geographical coordinates recorded in whole degrees and minutes, indicating latitude and longitude.

Visual survey of the area

Visual surveying of the area is used when it is necessary to obtain a plan of the area that is approximate in accuracy. Such plans are necessary for geographical surveys of the area, drawing up a plan for organizing any work on the ground and supplementing the map necessary for this moment. There are two types of eye survey: 1) survey of areas (areas of terrain) and 2) survey of routes ( narrow strip locality). To carry out eye survey you need: 1) a tablet-folder with a compass and a sheet of paper attached to it; 2) a sight line, along the upper edge of which the objects called up are drawn; 3) measuring compass and 4) pencils.

Preparing for shooting is as follows:

1. Preparing the tablet for work, that is, attaching the compass to the corner of a folder or sheet of plywood so that the diameter of the compass dial 0-180 ° is placed parallel to the edge of the plywood sheet.

2. Constructing on the tablet (in the southern part): a) a linear scale that corresponds to the numerical scale of the survey; b) linear scale of steps of the corresponding numerical survey scale.

The step scale is an ordinary linear scale on which distances measured on the ground in steps are plotted. The scale of steps corresponds to the metric scale of the survey and the step size of the person conducting the survey.

According to the scale of steps, distances directly measured on the ground will be plotted on the plan, and distances measured to local visual objects will be plotted on the plan using the metric scale.

Visual surveying can be carried out in two ways: 1) according to the “skeleton” compiled from the map, that is, by copying from the map the main lines of roads, ditches, boundaries of rectilinear contours 2) surveying on a blank basis.

The survey is carried out by walking around the site along its boundaries or along the lines of roads, ditches, and contour boundaries selected during reconnaissance, which are called running lines, and the turning points of running lines are called stations. So, visual shooting carried out from running lines and stations.

From the stations, shooting is carried out using the polar method or the circular sighting method: with the tablet oriented along the compass, they sight the object with a sighting ruler, located on the edge of the station images, measure the distance to the object by eye in meters and lay it along the edge of the ruler. In this case, the tablet must be held in your left hand at chest height and ensure that it is oriented.

Moving along the running line from station to station and measuring the running line in pairs of steps, we take pictures of the line itself and the objects on it using direct measurements. Photographing objects located on both sides of the running line at a short distance from it is carried out using the perpendicular method, remaining at the base of the perpendiculars, which are lowered from the points of local objects. Local items(pillars, towers, etc.) They are removed from stations and running lines by constructing a linear straight notch on the tablet, indicating the direction with a sight line.

The meaning of the card in life and economic activity person

Geographic maps include a huge scientific material. They are a source of knowledge. Thoughtful Study physical card gives general idea about the entire nature of the territory. Therefore for practical purpose needed detailed maps relief, soil, vegetation, climate, etc.

Based on the study of maps, mineral exploration, design and construction work is carried out railways, highways, pipelines, water structures.

Economic maps reflect the economy of the territory, provide a variety of characteristics or partial characteristics of one specific area (for example, industry). With the help of maps, a detailed study of the territory is carried out for correct geographical location industry and agriculture, construction of complex enterprises. Design of economic construction, which is carried out by dozens of research institutes associated with the development of diverse and complex maps.

Economic maps are used in feasibility design and planning. IN agriculture assessed using cards natural resource potential, reclamation is being carried out, issues are being considered economic efficiency development and placement.

Maps are used in the navigation of sea and river vessels, aircraft, spaceships. Indispensable cards in military affairs. They are reliable guides on hiking and hiking trails. Maps are an indispensable tool for school teaching.

Subject: Degree network on the globe and maps.

Lesson objectives:

• form an idea of ​​the degree grid on the globe andgeographical map, about the difference in the depiction of meridians and parallels on them;
• form an idea of ​​parallels and meridians, their characteristics: shape and length;
• learn to show lines of parallels and meridians on the globe;
• summarize the materials learned during previous lessons.

Equipment: student globes, map of hemispheres, PC, multimedia projector, presentation.

During the classes:

I. Organizational moment.

II. Checking homework.

Oral survey.

What is a geographic map?

What is the importance of a plan and a map in practical activities person?

On what scale map is the territory reduced by large quantity times: 1:5000 or 1:10,000?

Explain your point of view based on the definition of “scale”.

Card task: crossword puzzle “Globe and geographical map.”

Vertically:

1. Model of the globe with the outlines of land and water spaces.

2. A circle conventionally drawn along the surface of the Earth parallel to the equator.

4. A parallel drawn on the globe at equal distances from both poles.

Horizontally:

1. Points on the earth's surface through which the imaginary axis of the earth passes.
2. One three hundred and sixtieth part of a circle.

5. Conditional accepted line on the surface of the globe, drawn from pole to pole and crossing the equator at right angles.

III. Learning new material. Slide 1.

When we go to visit someone for the first time, we already know where to go, because we know the address: street, house and apartment number. Guys, let's take a closer look at the globe. Slide 2 . What do we see there?

That's right, the oceans and continents are clearly visible on the globe. What else is depicted on it in the form of a thin cobweb? ( lines)

These lines are drawn for a reason, but so that you can determine exact location object. Today we will take a closer look at these amazing lines.

You already know that there is a line on the globe equally distant from the poles. What is it called? ( equator).

Slide 3 What two parts does the equator divide the globe into? (northern and southern hemispheres).

Look, lines are drawn from the equator to the poles at equal distances. How do they go? (parallel to the equator).

Parallels called lines conventionally drawn along: the surface of the Earth parallel

equator.

Slide 4 Where on the map of the hemispheres are the parallels labeled? ( around the circumference) . In what units are the designations indicated? ( in degrees ). The equator is designated 0 0 .

What shape do all the parallels have? (circle shape). The equator is the most long parallel.

What is the length of the equator? ( 40,000 km ). How many degrees does a circle contain? ( 360 0). So the length is 1 0 The equator is 111.3 km.

Slide 5 Are all parallels the same length?

Length in kilometers 1 0 Each parallel is indicated from the edge of the map in an oval.

Look at the globe. Lines are also drawn from the North to the South Pole. Slide 6

Meridian called the shortest line conventionally drawn on the surface from one

poles to the other.

Analyzing the map of the hemispheres, students answer the following questions:

What shape do meridians have? ( semicircle ). Where on the map of the hemispheres are the meridians labeled? ( at the equator)

What direction does the meridian show on the earth's surface?

Translated into Russian, the word “meridian” means “noon line.” How can

explain this name" (When answering these questions, students use Fig. 25 p. 28).

Are all meridians the same length? How many kilometers will it be? ( 20,000 km). Length 1 0 each meridian is 111.3 km.

But the meridians are all the same, so where can you count? Slide 7 Scientists agreed to consider the prime meridian to be the one that passes through the Greenwich Observatory near London, so it was called Greenwich, or prime, or zero (designated 0 0 ). There is also a final meridian, it is designated 180 0 .

To make it easier to find the equator, prime and final meridians on the globe and maps, they are highlighted with a thicker line.

Slide 8 On globes and maps, meridians and parallels are drawn through same number degrees, for example after 10 0 or 15 0 . Lines of meridians and parallels on the globe and geographical maps, divided by degrees, are calleddegree grid. Slide 9.10

The degree network formed by meridians and parallels allows you to find any point on the Earth’s surface on a map and globe.

IV Consolidation.

Look at the map of the hemispheres.

What lines will replace the vertical rows ( meridians ) show on the map,

and horizontal ( parallels ), show on the map

Are all meridians the same length?

The prime meridian divides the earth into two hemispheres. Which ones show them on the globe and map.

The equator divides the Earth into two hemispheres. Which ones show them on the globe and map.

What does the degree network formed by meridians and parallels allow you to find on the map and globe?

V. Homework. Slide 11

§11, tasks No. 3, 4, 5, 6

Find the location of a variety of geographical objects on the map, as well as to navigate on it, the degree grid helps us.

What is a degree grid

The degree grid is a system of meridians and parallels. Meridians are invisible lines that cross our planet vertically relative to the equator. Meridians begin and end at the Earth's poles, connecting them. Parallels are invisible lines that are drawn conditionally parallel to the equator. Theoretically, there can be many meridians and parallels, but in geography it is customary to place them at intervals of 10 - 20 °. Thanks to the degree grid, we can calculate the longitude and latitude of an object on the map, and therefore recognize it geographical location. All points located on the same meridian have identical longitude, points located on the same parallel have the same indicators latitude.

Degree grid on maps

When studying geography, it is difficult not to notice that meridians and parallels are depicted differently on different maps. Looking at the map of the hemispheres, we can notice that all meridians have the shape of a semicircle and only one meridian, which divides the hemisphere in half, is depicted as a straight line. All parallels on the map of the hemispheres are drawn in the form of arcs, with the exception of the equator, which is represented by a straight line. On maps of individual states, as a rule, meridians are depicted exclusively as straight lines, and parallels can only be slightly curved. Such differences in the image of the degree grid on the map are explained by the fact that violations of the earth's degree grid when transferred to a straight surface are unacceptable.

The history of the invention of the Earth's degree grid

Parallels and meridians were drawn on the first geographical maps. Thus, the maps of Dicaearchus Messianus (3rd century BC), on which parallels were drawn, have been preserved to this day. First geographic grids had no degree differences: parallels and meridians were depicted as straight lines. In the second century BC, the scientist Hipparchus was able to create angular degrees on a degree grid. He entered into geographical science concept of latitudes and longitudes. Hipparchus was also the first to be able to create a geographic projection: transfer an image from a globe to a flat map.

The spherical shape of the Earth and daily rotation determine the existence of two fixed points on the earth’s surface - poles. The imaginary axis of the earth passes through the poles, around which the Earth rotates.

On maps and globes, the largest circle is drawn - the equator, the plane of which is perpendicular to earth's axis. The equator divides the Earth into the northern and southern hemispheres. The length of the 1° arc of the equator is 40075.7 km: 360° = 111.3 km.

Many planes can be conventionally positioned parallel to the equatorial plane. When they intersect with the surface of the globe, small circles are formed - parallels. They are drawn on a globe or map at a certain distance from the equator and oriented from west to east. The length of the parallel circles decreases uniformly from the equator to the poles. Let us recall that it is greatest at the equator and equal to zero at the poles.

The globe can also be crossed by imaginary planes passing through the Earth's axis perpendicular to the equatorial plane. When these planes intersect with the surface of the Earth, large circles – meridians. Meridians can be drawn through any point on the globe. They all intersect at the poles and are oriented from north to south. Average length arc 1º meridian 40008.5 km: 360° = 111 km. The direction of the local meridian at any point can be determined at noon by the direction of the shadow of a gnomon or other object. In the northern hemisphere, the end of the shadow of an object shows the direction to the north, in the southern hemisphere - to the south.

To calculate distances on a map or globe, you can use the following values: the arc length of 1º meridian and 1º equator, equal to approximately 111 km.

To determine the distance in kilometers on a map or globe between two points located on the same meridian, the number of degrees between points is multiplied by 111 km. To determine the distance in kilometers between points lying on the same parallel, the number of degrees is multiplied by the length of the arc of 1° parallel, indicated on the map or determined from tables.

Length of arcs of parallels and meridians on Krasovsky's ellipsoid

Latitude in degrees		Latitude in degrees	Length of the arc of a parallel of 1° in longitude, m	Latitude in degrees	Length of the arc of a parallel of 1° in longitude, m

For example, the distance between Kiev and St. Petersburg, located approximately on the 30° meridian, is 111 km * 9.5° = 1054 km; distance between Kiev and Kharkov (approximately parallel 50°) – 71 km * 6° = 426 km.

Parallels and meridians form degree network. The most accurate idea of ​​the degree network can be obtained from a globe. On geographic maps, the location of parallels and meridians depends on the map projection. To verify this, you can compare different maps, for example, maps of hemispheres, continents, Russia, Russian regions, etc.

The position of any point on the globe is determined using geographic coordinates: latitude and longitude.

Geographic latitude– the distance along the meridian in degrees from the equator to any point on the globe. The equator, the zero parallel, is taken as the origin of latitude. Latitude varies from 0° at the equator to 90° at the pole. North of the equator is counted northern latitude(n. latitude), south of the equator - southern (s. latitude.). On maps, parallels are inscribed on the side frames, and on a globe - on the 0° and 180° meridians. For example, Kharkov is located at 50° parallel north of the equator - its geographical latitude is 50° N. sh.; Kermadec Islands - in Pacific Ocean at 30° parallel south of the equator, their latitude is approximately 30° S. w.

If on a map or globe a point is located between two designated parallels, then its geographic latitude determined additionally by the distance between these parallels. For example, to calculate the latitude of Irkutsk, located on the map of Russia between 50° and 60° N. sh., a straight line is drawn through the point connecting both parallels. Then it is conditionally divided by 10 equal parts– degrees, since the distance between parallels is 10°. Irkutsk is closer to the 50° parallel.

In practice, geographic latitude is determined by altitude North Star using a sextant device; in school, a vertical goniometer or eclimeter is used for this purpose.

Geographic longitude– the distance along the parallel in degrees from the prime meridian to any point on the globe. The Greenwich meridian, the zero meridian, which passes near London (where the Greenwich Observatory is located), is taken as the origin of longitude. To the east of the prime meridian up to 180° the eastern longitude (E) is measured, to the west - the western longitude (W). On maps, meridians are inscribed on the equator or the upper and lower frames of the map, and on a globe - on the equator. Meridians, like parallels, are drawn through the same number of degrees. For example, St. Petersburg is located on the 30th meridian east of the prime meridian, its geographic longitude 30° E. d.; Mexico City - on the 100th meridian west of the prime meridian, its longitude is 100° W. d.

If a point is located between two meridians, then its longitude is determined by the distance between them. For example, Irkutsk is located between 100° and 110° east. etc., but closer to 100°. A line is drawn through the point connecting both meridians, it is conventionally divided by 10° and the number of degrees is counted from the 100° meridian to Irkutsk. Consequently, the geographic longitude of Irkutsk is approximately 104°.

Geographic longitude in practice is determined by the time difference between a given point and the prime meridian or other known meridian. Geographic coordinates are recorded in whole degrees and minutes, indicating latitude and longitude. In this case, 1º = 60 min (60"), a0.1° = 6", 0.2° = 12", etc.

Literature.

1. Geography / Ed. P.P. Vashchenko, E.I. Shipovich. - 2nd ed., revised and supplemented. - K.: Vishcha school. Head Publishing House, 1986. - 503 p.

“The degree grid and its elements on the globe and map”

Prepared by:

Anpadistova

Tat `yana Aleksandrovna,

a history teacher,

social studies and geography

MKOU "Central Center No. 12"

Uzlovsky district

Tula region".

Nodal

2018

The degree grid and its elements on the globe and map.

Sometimes it is very important for people in their business activities or in research to determine exact location any geographical objects on the surface of the Earth. This can be done using the degree grid, which is on every map or globe. It consists of lines of parallels and meridians. The location of any point on the globe is determined usinggeographical coordinates : latitude and longitude.

degree net formed by meridians and parallels.Meridian - the shortest line conventionally drawn on the surface of the Earth from one pole to the other.Meridians - these are the lines that are drawn on the globe through the North and South Poles. A meridian can be drawn through every point on the earth's surface. All meridians on the globe have the same length, it is equal to an arc of 1 ° and is almost 11 km.

Parallels - all points of one parallel are equidistant from the equator. The lengths of the parallels are different: they increase when approaching the equator and decrease towards the poles. All points on the same meridian have the same longitude but different latitude. All points of the same parallel, on the contrary, have the same latitude, but different longitude.

Parallel - lines conditionally drawn along the surface of the Earth parallel to the equator. The parallels on the map and globe are directed to the west and east. They are not equal in length. The longest parallel is the equator.

The equator is an imaginary line on the earth's surface, obtained by mentally dissecting the ellipsoid into two equal parts (Northern and Southern Hemisphere). With such a dissection, all points of the equator turn out to be equidistant from the poles. The plane of the equator is perpendicular to the Earth's axis of rotation and passes through its center. There are 180 meridians on Earth, 90 of them north of the equator, 90 to the south.On the map and you can spend as much time as you like, but usually for educational maps they are carried out at intervals of 10-20°. The parallels are always oriented from west to east.

Greatest parallel -equator . This circle is on the surface of the globe, all points of which depend on both poles at unequal distances.Equator - an imaginary line on the earth’s surface, obtained by mentally dissecting the globe with a plane passing through the center of the earth perpendicular to its axis of rotation.

All points on the equator are equidistant from the poles; it divides the Earth into two hemispheres - the Northern and Southern.The image of a degree grid on a plane, that is, on a map, is calledcartographic mesh .

Meridians and parallels are depicted differently on maps. For example, on a world map, meridians are straight, parallel to each other, while parallels are straight, perpendicular to the meridians. On the map of the hemispheres, only the middle meridian of each hemisphere and the equator are depicted with straight lines, and other meridians and parallels are depicted with curved lines.

Geographical latitude - the distance along the meridian in degrees from the equator to any point on the globe. The equator, the zero parallel, is taken as the starting point for latitude. Latitudes are calculated along the meridian from 0° to 90° on both sides of the equator and are called northern or southern accordingly.

Geographical longitude - the distance along the parallel in degrees from the prime meridian to any point on the globe. The Greenwich meridian, the prime meridian, which passes near London, is taken as the starting point for longitude. Longitudes to the east of the prime meridian, from 0° to 180°, are called eastern, to the west - western; are considered in parallel.

Geographic coordinates are recorded in whole degrees and minutes, indicating latitude and longitude.The points of intersection of the earth's axis with the surface of the globe are calledpoles (North and South). The Earth makes one revolution around this axis in 24 hours.

Geographic poles - mathematically calculated points of intersection of the imaginary axis of rotation of the Earth with the earth's surface. Meridians can be drawn through any points on the earth's surface, and they will all pass through both poles of the earth.

The meridians are oriented from north to south, and all have the same length (from pole to pole) - about 20,000 km. Average length of 1° meridian: 20004 km: 180° = 111 km. The direction of the local meridian at any point can be determined at noon by the shadow of any object.

In the Northern Hemisphere, the end of the shadow always points north, in Southern Hemisphere- South.The parallels of 23.5° north and south latitude are called tropical circles or simplytropics . On each of them, once a year the midday Sun is at its zenith, i.e. Sun rays fall vertically.

The parallels of 66.5° north and south latitude are calledpolar in circles . Through the Northern and South poles circles are drawn, meridians are the shortest lines, conventionally drawn from one pole to another.

Initial or Prime Meridian carried out by Greenwich Observatory(London, Great Britain). All meridians have the same length and semicircular shape. There are 360 ​​meridians on Earth, 180 to the west of the zero, 180 to the east.

The meridians on the map and globe are directed from north to south.The latitude and longitude of any point on Earth constitute its graphic coordinates. Thus, the geographic coordinates of Moscow are 56° N. and 38° east. d.