Flow difference between inland river and outflowing river: Generally speaking, the inflow of inland river is smaller than that of outflowing river, with large seasonal variation and small interannual variation.

Analyze the hydrological characteristics of rivers in China.

1. Hydrological characteristics of rivers in Northeast China (Heilongjiang, Songhua River, Nenjiang River and Wusuli River)

Abundant water (flowing through humid and semi-humid areas); Short flood season (spring flood-seasonal snowmelt water, summer flood-temperate monsoon climate, atmospheric precipitation); Low sediment concentration (dense forest and small terrain); The ice age is long (high latitude, located in cold temperate zone and middle temperate zone), and there are ice floods in Songhua River, Wusuli River and Heilongjiang Province. The water level changes little: there are two flood seasons; Shipping value: seasonal shipping (summer) is short of water resources (small topographic difference).

2. Qinling Mountains-North of Huaihe River-Liaohe River, Haihe River and Yellow River

Small amount of water: it flows through semi-humid and semi-arid areas; The water level changes greatly: the recharge is mainly precipitation in July and August; The flood season becomes shorter and the season becomes bigger: the precipitation season becomes shorter; High sediment concentration: there is little vegetation in the middle and upper reaches of the river, which flows through the loose soil area and causes serious soil erosion; Short ice age: short winter; Low shipping value: the middle and upper reaches fluctuate and the lower reaches are flat, but the sediment deposition is serious and the water volume is small; Hydropower resources: hydropower resources are relatively abundant in places with large gap between the middle and upper reaches, forming cascade development.

3. Hydrological characteristics of rivers south of Qinhuai River.

Abundant water: it flows through humid areas with abundant rainfall (long rainy season and wide drainage area); The water level changes little: the precipitation season is long; The flood season becomes longer and the season becomes smaller: there is more precipitation and less sediment concentration in the season; Vegetation protection is good; None during the ice age: the temperature in winter is above 0℃; High shipping value: downstream area (flat terrain and large water volume); Abundant hydropower resources: the middle and upper reaches are rich in hydropower resources (large amount of water, large gap).

4. Hydrological characteristics of rivers in southwest China.

Abundant water: the water level changes little when it flows through the humid area with abundant rainfall: the precipitation season is long; The flood season is longer and the season is smaller: there is more precipitation and the season is longer; Small sediment concentration: better vegetation protection; None during the ice age: the temperature in winter is above 0℃; Low shipping value: high mountains, deep valleys and many canyons; Abundant hydropower resources: large drop, many canyons and abundant water.

5. Hydrological characteristics of rivers (many inland rivers) in northwest China.

Small flow: flowing through arid and semi-arid areas (glacier melt water supply and mountain precipitation supply); Seasonal variation of water level: Glacier meltwater is the main supply, which is greatly affected by temperature, and most of them are seasonal rivers (cut off in winter) or seasonal rivers; Flood season: short (summer flood season); The shipping value and water energy value are very low; Process: not long time (evaporation, infiltration, more irrigation water).