Western Block (North China Craton) - Geography

Geography

The Eastern Block of the North China Craton consists mainly of the densely settled and very fertile North China Plain, one of the most densely populated rural regions in the world. It is drained chiefly by the lower reaches of the Huang He and Hai He, both of which are among the siltiest rivers in the world and provide enormous amounts of essential plant nutrients when they flood during the summer. The climate of the North China Plain is humid but continental, with most precipitation occurring between June and September, though significant falls in winter do occur in the southern part of the region. Annual rainfall in the southern part of the North China Plain averages around 1,150 millimetres (45 inches), but declines to around 600 millimetres (24 inches) in the north. Temperatures vary widely, but summer is always hot with the average July maximum usually around 31 °C (88 °F) with high humidity. January temperatures range from about 3 °C (37 °F) in the extreme south to −10 °C (14 °F) north of Beijing.

In complete contrast, the Western Block is a dry, elevated plateau averaging over 1,000 metres (3,300 ft) in elevation and having a dry and extremely continental climate. Annual rainfall is typically only around 300–400 millimetres (12–16 inches) and winter temperatures are often as low as −20 °C (−4 °F), whilst summers can be blistering. Because of the huge accumulations of loess from Himalayan glaciation, the soils are very fertile when irrigated, but water shortages remain a serious problem for farmers. Sheep are grazed in large numbers away from the rivers.

The Central Orogenic Belt is mainly rocky mountains up to 2,360 metres (7,740 ft) in elevation. Because of the extreme cold and erosion risk, most of this mountainous land is not cultivated and in places extensive forests still remain.