Arid regions cober arid and semiarid areas. 旱区包括干旱区和半干旱区。
Desertification is a process caused by the conflict between the low productivity of the arid land and the ever increasing material and social demand of human beings. 沙漠化是由于干旱半干旱区土地很低的生产力与人民群众日益增长的物质文化需要不相适应造成的。
