YU Jing-jie, REN Hong-zun

(Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China)

Abstract: North China is one of the most important grain production bases of the country and plays an important role in the national food security. The present population, cultivated land and crop production all have exceeded 1/4 of the national total. The crop yield accounts for 22% of the national total crop yield in 1949 and 29.6% of that in 1998. Irrigation serves as an essential guarantee to obtain high stable crop yield in the region because the distribution of water resources is inconsistent with the regional arable land, light and heat.

The water resources in North China are characterized by water shortage per capita and per unit arable land as well, uneven distribution in space and in time, and stable ground water resources. The status of water use in North China is quite serious, per capita water use amount is 315 m³ in 1997. Agriculture is the main water consumer, and the water consumption in agriculture is 5 times as much as that in industry. The conflict between water supply and demand in agriculture is becoming more and more severe. While the future water supply for agriculture will be quite unpleasant both in quantity and quality. First, there is no much water supply potential left since the water resources exploitation rate is 98.5%. Second, the agriculture water supply quota is going to decrease in the process of industrialization and urbanization in North China.Third, the water supply guarantee will be lowered resulted from frequent drought and flood, severe water pollution and extensive groundwater level decline.

The water supply for agriculture can not meet the water demand to maintain and raise the crop yield in North China if there is no successive high flow years or no new water sources. Therefore, it is urgent to make a set of feasible measures in order to solve the conflict between crop production and water shortage.

Keywords: North China; crop yield; water supply; analysis