"Rivers and Lakes" PPT courseware

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"Rivers and Lakes" PPT courseware

Part I: Geographical overview of rivers and lakes

1. Basic characteristics

(1) There are many rivers in our country

There are more than 1,500 rivers with drainage areas exceeding 1,000 square kilometers. However, the regional distribution is uneven, and the density of the river network decreases from southeast to northwest.

(2) Abundant water

The annual ranking of rivers is: Brazil>Russia>Canada>United States>Western India>China. The total annual runoff is more than 2.7 trillion cubic meters, but it varies greatly within and between years, with abundant water in summer, low water in winter, and the transition from spring to autumn.

(3) The water energy reserves are huge

The world's exploitable water energy ranking: China>Russia>Brazil>United States>Canada. The hydropower resource reserves reach 680 million kilowatts, ranking first in the world, but the distribution is uneven. The Yangtze River's hydropower resources account for 40% of the country's hydropower resource reserves.

2. Main rivers

①Pearl River: Xijiang, Beijiang, Dongjiang

②Yangtze River (Tuotuo River, Tongtian River, Jinsha River):

Yalong River, Dadu River, Minjiang River, Jialing River, Wujiang River,

Yuanjiang, Xiangjiang, Hanjiang, Ganjiang

③Huaihe River

④Yellow River: Huangshui, Taohe, Fenhe, Weihe

⑤Haihe

⑥Liaohe River

⑦Heilongjiang: Songhua River (Nen River, Second Songhua River), Wusuli River

Others: Minjiang River, Qiantang River, Luanhe River, Yalu River

3. Hydrological characteristics of major rivers

From what aspects should we understand the characteristics of a river?

It is most important for us to study the hydrological characteristics of rivers, which mainly include the water level, flow, sediment content, whether it is frozen, and water energy reserves.

Water level (flood season, dry season, no flow, dry up): high, low, long, short, spring flood, summer flood, winter flood;

Water volume (flow): abundant, large, small;

Sand content: large, small;

Whether there is ice period: yes, no, long, short;

Water energy reserves: large and small.

Rivers and Lakes PPT, Part 2: Hydrological Characteristics and Causes of Outflow Rivers

Hydrological characteristics and causes of outflow rivers in different regions of my country

⑴Northeast (Heilongjiang and its tributaries, Songhua River):

Characteristics: Large flow rate. Short flood season (spring flood, summer flood). Small sediment content. Long freezing period.

Reasons: It flows through humid and semi-humid areas. Seasonal snow melts in spring. The rainy season is short in summer. The forest is dense.

The latitude is higher and the winter is long.

⑵The water system north of Qin-Huai River (Liaohe River, Haihe River, Yellow River):

Characteristics: small flow, short flood season (summer flood, ice flood in the Yellow River), large sand content, and short freezing period.

Reason: Most of the areas it flows through are semi-humid areas. The vegetation in the basin is poor. The rainy season is short. It is located in the mid-temperate zone.

(3) Qin-Huainan (Yangtze River and Pearl River) water system:

Features: large flow, long flood season (the further south, the longer the flood season, and the smaller the seasonal changes in river runoff, summer floods. The Pearl River has Taiwan floods). The sediment content is small. There is no ice period.

Reasons: It flows through humid areas. The vegetation is better. The rainy season is longer. Most areas are above the 0°C isotherm.

Rivers and Lakes PPT, Part 3: Hydrological Characteristics and Causes of Inland Rivers

Hydrological characteristics and causes of inland rivers in China

⑴ Mainly distributed in the northwest inland: Tarim River. Weak water.

⑵Hydrological characteristics:

The flow is small, the flood season is short, the sand content is large, it freezes in winter, there are many seasonal rivers, and the flow is short.

⑶Causes of formation:

The amount of supply is small. The vegetation conditions are poor. The temperature in winter is below 0℃.

⑷Main supplies:

Tarim Basin: Rivers such as the Tarim River. Its water supply source is mainly permanent mountain ice and snow melt water. Its flood season is related to temperature.

Junggar Basin: Water supply is mountain precipitation and permanent mountain ice and snow melt water.

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"Rivers and Lakes" PPT:

"Rivers and Lakes" PPT Part One Content: Many Rivers and Lakes In the vast land of the motherland, there are many rivers flowing, including more than 20 rivers with a length of more than 1,000 kilometers, and rivers with a drainage area of ​​more than 1,000 square kilometers. There are more than 1,500. I..

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Update Time: 2024-10-07

This template belongs to Geography courseware Business Planet Edition Geography for Grade 8 Volume 1 industry PPT template

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