Geography: a general answer term for all kinds of common questions in geography examination.

1. Small topic of contour topographic map:

(1) The dam site of the reservoir is located in a river canyon because:

① Located in the canyon area, the geological conditions are good, which is beneficial to dam construction, and the engineering quantity is small; (2) The reach above the dam is rich in water resources, with a large basin topography and water storage capacity; (Sometimes it is necessary to take into account that there are few flooded farmland and the scale of immigration is small. )

(2) Reasons for choosing the route scheme of transportation lines (railways and highways):

The plan has sparse contour lines along the line, gentle terrain gradient, easy construction, short construction period and low investment. (Hint: Generally, it bypasses between two contour lines and distributes along the contour lines (extension direction), crossing rivers and mountains as little as possible, and building fewer bridges and tunnels; Avoid passing cliffs, swamps, deserts, etc. )

(3) Determine a terrain as a basin, and judge the reason:

Rivers converge to the middle to form a centripetal water system, indicating that the terrain is low in the middle and high around. (The elevation on the contour line is low in the middle and high around. )

(4) The reason why the water diversion project chooses a certain place is that the terrain is relatively high, and the river can naturally flow down along the terrain.

5] Choose a place as a terrace for the following reasons:

The terrain is gentle and the slope is small. Reclaiming terraced fields here can not only expand the cultivated land area, but also be beneficial to soil and water conservation, realize the unity of ecological, economic and social benefits and realize sustainable development.

[6] Choose a mountaineering route. The reason is that the contour line of the route is sparse, the terrain slope is small and it is easy to climb.

(7) Calculate the slope between the two places: slope (tangent) = vertical relative height/horizontal field distance.

2. Small topic of marine resources:

(1) Fishery resources are concentrated in temperate coastal continental shelf waters for the following reasons:

Here (1) is the continental shelf water with shallow seawater, abundant sunshine and strong photosynthesis; (2) The confluence of cold current and warm current (or the flooding of cold seawater in winter) brings nutrients from the seabed to the surface; (3) rivers into the sea bring rich nutrients. The above conditions make plankton flourish in this sea area, and fish bait is sufficient, which is easy to form a large fishing ground.

(2) Distribution law of seabed mineral resources:

① Coastal placer in the nearshore zone: there are building materials and metal minerals such as sand and shells.

② Shallow sea bottom of continental shelf: There are mineral resources such as oil, natural gas, coal, sulfur and phosphorus.

③ Basin: deep-sea manganese nodules (mainly concentrated in the North Pacific)

3. Salinity and ocean currents:

(1) the highest salinity is the red sea, because:

① Located in subtropical sea area, precipitation is scarce and evaporation is strong. ② Surrounded by a tropical desert climate zone, there is little fresh water flowing in from the land.

(2) The lowest salinity is in the Baltic Sea for the following reasons:

① Located at higher latitude, with low temperature and weak evaporation. ② Surrounded by temperate maritime climate zone, there is more precipitation and more fresh water injection.

(3) The reason why Balkhash Lake is salty in the east and weak in the west:

① East: located inland, with scarce precipitation and strong evaporation; Lack of fresh water injection from rivers.

② West: There is river fresh water injection, which has strong dilution effect.

③ The middle part of Balkhash Lake is narrow, which is not conducive to the water exchange between the east and west sides, resulting in a great difference in salinity between the two sides.

(4) Horizontal distribution law of salinity in surface seawater of the world:

From the subtropical waters in the northern hemisphere and the southern hemisphere to the low-latitude waters and high-latitude waters on the north and south sides, respectively.

5] to judge the nature of an ocean current as a cold (warm) current, the judgment reason is:

Temperature: the temperature of the sea area where ocean currents flow is lower (higher) than that of other sea areas at the same latitude.

Flow direction: from high (low) latitude sea area to low (high) latitude sea area, [or from low (high) water temperature sea area to high (low) water temperature sea area].

4. Small topic about rivers and traffic:

(1) Changes of the names of the China South Flowing River at home and abroad;

Yarlung Zangbo River-Brahmaputra River Dulong River-Irrawaddy River Nujiang River-salween Lancang River-Mekong River Yuanjiang-Red River

Other international rivers in China:

Irtysh River-ob river Heilongjiang is called amur river in Russia.

(2) The reasons why rivers in Western Europe have great shipping value:

Rivers are rich in water, stable in water level, small in sediment concentration and free from ice age; The terrain in the basin is flat, the river gap is small, the industry is developed, the freight volume is large, and the shipping value is great.

(3) ob river (Yenisei River and Lena River) is of little shipping value:

High latitude and long freezing period; Rivers generally run from south to north, and there is a phenomenon of ice flooding, which is not conducive to shipping.

Because the Amazon River is located in the tropical rain forest area, dense rain forest vegetation hinders navigation; The river basin is sparsely populated and has little shipping value.

⑷ Significance of polar route development: shortening voyage, saving time and effort.

5] southwest China is rich in hydropower, mainly because:

① Located in humid area, with abundant precipitation and large runoff; ② Located at the junction of the first and second steps, the river has a large drop.

Variant: The Three Gorges area is rich in hydropower, mainly because:

① Located in humid area, with abundant precipitation and large runoff; ② Located at the junction of the second and third steps, the river has a large drop.

Significance of the construction of Nanning-Kunming Railway: Economic significance: ① It is conducive to the development of resources and the export of materials, and turns the resource advantage into economic advantage. (2) It is conducive to developing tourism resources and promoting the development of the tertiary industry. (3) It is conducive to giving play to the economic radiation function of the railway, driving the economic development along the railway and promoting the development of export-oriented economy.

Political significance: ① It is conducive to consolidating and strengthening national unity. (2) It is conducive to accelerating the speed of poverty alleviation in Southwest China. ③ Conducive to social stability.

Strategic significance: ① It is conducive to speeding up opening to the outside world and developing export-oriented economy. (2) It is conducive to consolidating national defense and defending the frontier.

The significance of trans-siberian railway once built by Russia;

(1) Strengthen the economic ties between the east and the west and promote material exchanges; (2) Accelerate the development of resources and turn resource advantages into economic advantages;

5. Small topics in geology and topography:

(1) The discovery of abundant coal in the Antarctic (there is abundant oil buried in the Arctic) shows that:

The Antarctic (Arctic) region was once located in a warm and humid area with dense forests, and then drifted here through the mainland, which is a strong evidence of plate tectonic theory.

(2) Reasons for the formation of Congo Basin:

Congo basin used to be an inland lake, which was formed by crustal uplift, river erosion and lake outflow.

(3) Causes of the Dead Sea (Lake Baikal, Lake Tanganyika, Fenhe River Basin and Weihe River Basin): internal force-crustal fracture and collapse.

(4) The causes of the five major freshwater lakes in North America (European fjords and lakes): external force-glaciation.

5. Formation of Lushan Mountain (Huashan Mountain and Taishan Mountain): a massive mountain formed by faults.

[6] Topographic features of seven continents:

Asia: ① The terrain is complex and changeable, with ups and downs, and the plateau and mountainous areas are wide; The terrain is high in the middle and low around, and the plains are mostly distributed in the middle and lower reaches of rivers;

Non-continental: ① the terrain is mainly plateau, and the horizon is not large; (2) A huge East African Rift Zone runs through the east; ③ Topographic features: high in the southeast and low in the northwest.

Europe: ① Europe is dominated by mountains and plains, with a vast plain area, accounting for 2/3 of the total area;

② The terrain is low and flat, which is the lowest continent in the world (300m), with high terrain in the north and south and low terrain in the middle; ③ Glacial landforms are widely distributed.

North America: ① The terrain is high in the east and low in the west; ② Glacial landforms are widely distributed in the northern half of the mainland.

(3) There are three terrain areas in the north and south, with mountains in the west, low mountains and plateaus in the east and plains in the middle;

South America: ① the Andes from north to south in the west; (2) The eastern plains and plateaus are arranged alternately.

Oceania: ① The terrain is low and flat. The surface is gentle and undulating; (2) The terrain is three longitudinal zones in the north-south direction, with mountains in the east, plains in the middle and highlands in the west.

Antarctica: ① The continent with the highest average altitude in the world (2350 m); (2) Continental glaciers are widely distributed, with an average thickness of 2,000 meters and diverse subglacial topography.

Causes of serious geological disasters in southwest China;

Natural reasons: ① Located in the earthquake zone, the crustal activity is strong and faults are developed in the mountain; ② The mountainous area is vast, with broken rocks and severe weathering; ③ The wet and dry seasons are distinct, and the rainstorm is concentrated.

Man-made reasons: the vegetation is seriously damaged.

6. Flood and waterlogging theme:

(1) Causes of severe floods in Bangladesh:

Natural reasons: ① strong southwest monsoon, abundant precipitation and heavy rainfall; (2) Ganges River and Yarlung Zangbo River meet here and enter the flood season at the same time; ③ Low terrain and poor drainage; (4) The southwest monsoon makes seawater flow northward into the Bay of Bengal, which prevents the river from entering the sea.

Man-made reasons: high population density, more vegetation destruction in the upper reaches, serious soil erosion, serious sediment deposition in the delta and shallow riverbed.

(2) Causes of frequent droughts and floods in India:

Strong southwest monsoon, or coming early and leaving late, is easy to cause waterlogging; Otherwise it will cause drought.

(3) The reason for the large flow of Amazon River:

① Located near the equator, affected by equatorial depression, there are more updrafts and abundant precipitation;

(2) The plain terrain and the north, west and south terrain are relatively high and open to the east, which is conducive to the entry of Atlantic water vapor;

(3) After entering inland, water vapor is lifted by plateaus and mountains, mostly topographic precipitation; ④ The basin area is vast, and the surface water is collected on three sides of the Amazon River.