China's annual runoff depth and the river's recharge type online map

China's annual runoff depth and river water recharge types

1. Annual runoff depth

Rain or snow melt in gravity, along the surface or in the underground flow and into the river flow called runoff. A certain period of time out of a catchment area of water called runoff, the unit to cubic meters; the water level in the catchment water depth called runoff depth, namely the total annual runoff and catchment area ratio, unit In millimeters. Runoff is a direct cause of changes in the water environment of rivers and lakes, and is also the most important hydrological process of land water. The annual runoff depth is affected by the natural factors such as climate, topography and underlying surface. The distribution of annual runoff depth in China is very uneven, which is descending from the southeast half to the northwest. The coastal area is larger than the inland and the mountain area is larger than the plain, especially the windward slope is much larger than the adjacent plain and basin. Height increase and increase. Northwest inland basin, due to the scarcity of precipitation, mostly no flow area, the annual runoff depth is the smallest, less than 5 mm.

2. River water recharge type of river

Ⅰ Rainwater recharge

Ⅱ rainwater, melt water supply

Ⅲ melt water, rain water supply

Ⅳ Groundwater, anhydrous or temporary water recharge

The map comes from China's annual Geography Atlas of China's annual runoff depth and river water supply types