Geographical conditions of river basin development

Section II Comprehensive Development of Rivers —— Taking Tennessee Valley in the United States as an Example

Knowledge network

Natural background of river basin development

1. Terrain

Give priority to

2. Climate

In subtropical areas, water and heat are abundant. Seasonal distribution of precipitation: more in late winter and early spring, relatively less.

3. Water system

There are many tributaries, rich but uneven water, and strong ability; Big gap, rich.

4. Minerals

Magnesium, iron, copper, phosphorus, zinc and mica are abundant.

Early basin development and its consequences

1. Land degradation

In the old cotton area, cotton consumes a lot of soil fertility, resulting in

2. Vegetation destruction

In order to expand the cultivated land area, obtain charcoal for copper smelting, and cut down forests on a large scale; Mining also destroyed the surface vegetation. lead to

3. Environmental pollution

Acid rain is formed by copper smelting enterprises, which leads to soil and water pollution and makes many organisms extinct.

Comprehensive development of river basin

1. Flood control

2. Ships

generate electricity

Cheap and reliable power supply. It has promoted the development of energy-intensive industries such as aluminum smelting and chemistry in this basin.

4. Improve water quality

Take measures such as,, and environmental improvement to improve the water quality of the reservoir and ensure the use of water.

travel

6. Land use

Basic proving ground

Test site 1 watershed and water system

Watershed, also known as water supply area, refers to the surface catchment for supplying river surface water and the underground catchment for supplying groundwater, generally referring to the surface catchment. The mountains or river highlands between adjacent river basins are called river basins. The line connecting the highest point of a watershed is called a watershed or watershed. Water system refers to a huge system formed by the interconnection of the main stream, tributaries and lakes, swamps or underground rivers in the basin, also known as water system. It collects the surface water and groundwater of the whole basin, and finally pours into the ocean, lake or disappears into the desert. The river system consists of a main river and a series of tributaries. Generally, the tributaries that flow into the main stream are called primary tributaries, and those that flow into primary tributaries are called secondary tributaries, and so on.

For example, the Mississippi River is the main stream, the Ohio River is the primary tributary, the Tennessee River is the secondary tributary of the Ohio River, and the Cumberland River meets the Tennessee River near Kentucky and is the tertiary tributary of the Mississippi River. Second, the importance attached by different regions of the river basin to the environmental protection of the test site.

minute

meaning

Key points of protection

hilly area

It is the birthplace of rivers, and its ecological environment directly affects the quantity and quality of rivers.

We should protect its vegetation ecology.

river

It is the main body of the basin development and utilization.

In the process of utilization, attention should be paid to the rational distribution of water resources and water quality protection.

Valley plain

It is an area where human activities are concentrated.

It is the focus of ecological environment protection.

Natural background of the development of Sanjiang basin in the experimental center

1. The physical and geographical features of the basin largely determine the utilization mode of rivers and the development direction of the basin.

2. Physical and geographical features of Tennessee Valley

(1) Topography: There are many mountains in the basin, with large topographic relief and abundant hydraulic resources.

(2) Climate: subtropical climate, warm and humid, rainy in winter and spring, relatively less in summer.

(3) Water system: The water system is developed, with numerous tributaries, abundant water and large seasonal variation of flow, and most of them are navigable.

(4) Mineral resources: rich in magnesium, iron, copper, phosphorus, zinc, mica, etc.

Early development of four major river basins in the experimental center and its consequences

/kloc-in the second half of the 0/8th century, human beings had little influence on the geographical environment; /kloc-In the late 20th century, large-scale predatory development brought a series of ecological and social problems. In the 1930s, it became one of the poorest areas in the United States.

Ecological and environmental problems

Cause of occurrence

consequence

land deterioration

In the old cotton area, cotton consumes a lot of soil fertility.

Decline of old cotton areas

Vegetation degradation

In order to expand the cultivated land area, obtain charcoal for copper smelting, and cut down forests on a large scale; Mining also destroyed the surface vegetation.

Soil erosion and deterioration of ecological environment

environmental pollution

Sulfur dioxide emitted by copper smelting enterprises forms acid rain.

Polluted soil and water, making many creatures extinct.

Comprehensive development of five major river basins in Kaodian

Cascade development in Tennessee Valley is the core of watershed development. Cascade development should first build dams, which can regulate river runoff and realize comprehensive benefits such as flood control, aquaculture, irrigation, shipping, power generation, tourism, etc., and combine the utilization of resources in the basin with the restoration and management of ecological environment to achieve the unity of economic, social and ecological benefits. Among them, the most obvious effect is economic benefit. It mainly includes: (1) flood control: 35 flood control reservoirs have been built, with an average annual flood control and disaster reduction benefit of about 200 million US dollars. (2) Shipping: The shipping benefit of Tennessee River water transportation is about $400 million less than that of land transportation every year. (3) Power generation: cheap and reliable power supply. It has promoted the development of high energy-consuming industries such as aluminum smelting and chemistry in the basin, and formed an "industrial corridor" on both sides of the Tennessee River. (4) Improve water quality: Take measures such as pollution prevention, water conservation forest protection, and ecological environment improvement in the reservoir area to improve the water quality of the reservoir and ensure the domestic water and agricultural irrigation water for residents. (5) Tourism: Tourism revenue has become an important source of financial revenue in the basin, which has promoted the development of cruise ship manufacturing and management. (6) Land use: Establish nature reserves, adjust the structure of agriculture, forestry and animal husbandry, and effectively control soil erosion. In addition, the land ecology in the mining area has been restored and treated. war game

[Example 1] The following is a map of a city in southwest China. Because a large chalcopyrite (CuFeS2) has been discovered nearby, it is planned to build a smelter and a hydropower station. Answer the following questions accordingly. (1) It is reasonable to build the hydropower station in one of the two places, A and B, for the following reasons. (2) After the completion of the hydropower station, it will have a beneficial impact on agriculture in this area. (3) From the perspective of social stability, the construction of hydropower stations still needs to solve problems. (4) The advantages of building a smelter near a copper mine are. The adverse effects on the environment are as follows. Analysis (1) The site selection of hydropower station should be considered from three aspects: first, the amount of dam construction is small, and it is generally chosen to be built in the canyon; The second is water storage capacity, which must have water to store; Third, the benefit is high, and the comprehensive benefit is pursued by dam repair and water interception, which can not only intercept water for flood control, but also (2) the downstream of B is a large irrigated agricultural area. After the dam is completed, it can store flood and prevent waterlogging in flood season, and release water for irrigation in dry season to ensure stable and high agricultural production. (3) As can be seen from the figure, there are three residential areas in B, where building dams will flood farmland houses. Therefore, it is necessary to do a good job in resettlement from the perspective of social stability. (4) Copper smelting is an industrial sector with high energy consumption, and its layout should point to thermal power stations or hydropower stations. Building a hydropower station at B is quite beneficial to copper smelting. However, during the smelting process, a large amount of waste gas containing sulfur dioxide, waste water and waste residue are inevitably discharged, which pollutes the local atmosphere, water body and land.

Answer (1)B The amount of dam construction is small, the water collection is easy, and the drop is large. (2) The flood disaster is reduced and irrigation is convenient. (3) The resettlement site is close to the origin of raw materials, and the cheap waste gas (mainly sulfur dioxide), waste water and waste residue generated in the process of copper smelting by hydropower can be obtained nearby, polluting the local atmosphere, river water and farmland.