College Entrance Examination Geography: Classification and summary of important knowledge points, a must for sprinting before the exam!
Slope problem: at first glance, the density of the contour lines, the slope is steep in dense places, and the slope in sparse places is gentle;
College entrance examination
Contour topographic map subtopic
1. Slope problem: at first glance, the density of the contour lines, the slope is steep in dense places, and the slope in sparse places is gentle;
Calculation: Tangent of Slope = Vertical Relative Height / Horizontal Field Distance
2. The problem of visibility: It can be solved by making a topographic profile. If the topographic profile made by two known points is not blocked by mountains or ridges, the two places can see each other; ) is not visible, and the concave slope (dense and sparse on the contour line) is visible; pay attention to the requirements in the question, the landscape map in the analysis diagram is visible from upward or downward.
3. Water diversion line: pay attention to let it divert water from a high place to a low place to achieve self-flow, and the line should be as short as possible, so that the economic investment will be less.
4. Transportation route selection: Taking advantage of favorable terrain and topography, it is necessary to consider not only the length of the distance, but also the stability of the route (spacing, slope, etc.) ) distribution to reduce the slope, and only pass through one or two contour lines when necessary; pass through rivers as little as possible, build fewer bridges, etc. to reduce construction difficulty and investment; avoid passing through cliffs, swamps, deserts, etc. Lot.
5. Reservoir construction: consider the reservoir site, dam site and whether resettlement is required after the reservoir is built.
①Choose at the exit of narrow rivers or basins and depressions (that is, "pocket-shaped" areas, "small mouth" is conducive to dam building, "big pocket" has a wide hinterland and large storage capacity. Because of the small amount of engineering, the engineering cost is low) ;
②Choose in a place with better geological conditions, try to avoid faults, karst landforms, etc., to prevent induced reservoir earthquakes;
③Considering the land occupation and relocation, try to flood fertile fields and villages and towns as little as possible. ④Also note that when building the reservoir, the water source should be more sufficient.
6. River flow: it flows from high altitude to low, developed in river valleys (high value of contour line), and the flow direction of river is opposite to the convex direction of contour line.
7. Water system characteristics: The mountain forms a radial water system, the basin forms a centripetal water system, and the ridge becomes the water system watershed.
8. Hydrological characteristics: river valleys with dense contour lines, high river velocity and abundant water energy; river flow is not only related to climate, especially precipitation, but also to the size of the basin.
9. Agricultural planning: According to the terrain type, undulations, and gradients reflected by the contour topographic map, combined with climate and water source conditions, a plan for the rational layout of agriculture, forestry, animal husbandry and fishery should be put forward according to local conditions; Develop forestry and animal husbandry in hilly areas.
10. Urban layout form and terrain: the plains are suitable for concentrated and compact; the mountainous areas are suitable for scattered and loose.
11. Description of terrain features: terrain types (plains, plateaus, mountains, hills, basins); terrain and relief conditions; distribution of major terrain areas; important terrain profile features.
12. Terrain correlation analysis:
①Analysis of formation causes: using geological action (internal force - crustal movement, magmatic activity, metamorphism, earthquake; external force - flowing water, wind, ocean waves, erosion, transportation, deposition of glaciers, etc.) and plate movement (internal plate movement) The crust is relatively stable, at the junction of plates, the crust is relatively active, and the collision or cracking of plates) is used to interpret and analyze the geographical knowledge related to topography.
② To analyze the climatic characteristics of a certain place, a comprehensive analysis should be carried out in combination with the geographical latitude of the place, the ups and downs of the terrain, the direction of the mountains, the shady and sunny slopes, and the distance from the ocean.
③The upper reaches of the river are high in altitude and the downstream is low. Combined with the river flow direction to determine the general terrain trend, combined with the windward slope, leeward slope, precipitation conditions, contour height differences and differences in landform types to analyze the river hydrology and water system characteristics.
④ Interpretation of terrain type: The first step is to look at the shape of the contour lines. If the contour lines are straight, it may be plain terrain or plateau terrain. If the contour lines are closed, it may be hills, mountains or basins;
The second step is to look at the annotation of the contour line. The terrain below 200 meters may be a plain, and the terrain above 500 meters may be a plateau; The terrain with the outer height is a basin or depression; the closed contour line marks the outer low and the inner high, and the terrain marked between 200 and 500 meters is hills, and the terrain above 500 meters is mountains. When interpreting the terrain type in the profile diagram, it is necessary to look at the profile shape and the corresponding altitude. The method can refer to the above method.
1. Analysis trend (extending direction): parallel to the latitude line, that is, east-west trend - latitude factors or solar radiation; parallel to the coastline - sea and land properties or distribution of sea and land; parallel to the contour line or mountain trend - terrain factors.
2. Analyze the bending condition: make the horizontal line method - compare the temperature at the bend and the intersection point; convex value method - the convex height (convex to the high value area) is low (low value), and the convex low (convex to the low value area) is high (value is high).
3. Analysis of density and density: sparse—small temperature difference—my country’s July temperature, tropical regions, oceans, mountain steep slopes, and fronts; dense—large temperature difference—my country’s January temperature, temperate regions, land, and mountain gentle slopes.
4. Analysis of numerical characteristics: large and small, large and middle; closed curves are large or small; high-value areas - summer continents, winter oceans, warm currents, low terrain (valleys, basins or depressions), cities; low-value areas - - Winter continent, summer ocean, cold currents, high terrain (mountains, ridges).
5. College Entrance Examination Ability Requirements:
(1) Judging the position of the southern and northern hemispheres: the degree of isotherm gradually decreases from north to south or the degree of isotherm gradually increases from south to north is the southern hemisphere. It is the northern hemisphere that gradually increases in degrees from north to south isotherms or decreases in degrees from south to north isotherms.
(2) Judging the location of land and ocean: the isotherms on land in winter are curved to low latitudes (indicating that the land in winter is cooler than the ocean at the same latitude), and the isotherms on the ocean are curved to high latitudes (indicating that the oceans in winter are cooler than the same latitudes) high land temperature). Isotherms over land in summer are curved toward high latitudes (indicating that the land is warmer in summer than the ocean at the same latitude), and isotherms over the ocean are curved toward lower latitudes (indicating that the oceans are cooler in summer than land at the same latitude).
(3) Judging the month (January or July): When judging the month, pay attention to the differences between the winter and summer seasons in the southern and northern hemispheres.
January: Isotherms over land in the northern hemisphere bend south and isotherms over oceans bend north; isotherms over land in the southern hemisphere bend south, and isotherms over ocean bend north.
July: Isotherms over land in the northern hemisphere bend north and isotherms over oceans bend south; isotherms over land in the southern hemisphere bend north and isotherms over ocean bend south.
(4) Judgment of cold and warm currents: The direction of the ocean current is consistent with the bulging direction of the isotherm. The water temperature in the center of the cold current is lower than that in other areas at the same latitude, so the isotherm curves to low latitudes. The water temperature in the center of the warm current is higher than that in other areas of the same latitude, so the isotherm curves to high latitudes.
(5) Judging the high and low undulations of the terrain: where the isotherm on the land bulges to low latitudes, it means that the terrain is elevated; On the closed isotherm map, the closer to the center, the smaller the value of the mountain isotherm; the larger the value of the basin isotherm.
(6) Judging the size of the temperature difference: under normal circumstances, regardless of time and space, the isotherms are dense, and the temperature difference is large; otherwise, the temperature difference is small.
© From the characteristics of temperature distribution in the world and my country, we can see that:
①The isotherms are dense in winter and sparse in summer. Because the temperature difference in winter is larger than that in summer.
②The isotherms in the temperate zone are dense, and the isotherms in the tropics are sparse. Because the temperature difference in temperate regions is greater than that in tropical regions with year-round high temperature.
③The land isotherm is dense, and the ocean isotherm is sparse. Because of the complex morphology of the land surface and the large heat capacity of the ocean, the temperature difference of the land is greater than that of the sea surface.