ABSTRACT
This chapter explores the general process of identifying and documenting the drought. Drought frequency appears to be increasing, particularly in the northern China, partly as the result of increasing human pressure on the resources: 'drought trend and human activity in northern China have induced more severe environmental problems. By comparison with most other natural disasters, in terms of the area affected and the duration of the effects drought has been identified as a 'pervasive' rather than an 'intensive' phenomenon. Environmental change and human activity through the hydrological cycle has resulted in the runoff variation in Northwest China, no-flow in the lower reach of the Yellow River and the salinization of soil in Northwest China'. The US National Oceanic and Atmospheric Administration (NOAA) extended its research to use such data together with the media reports to provide the global coverage of annual drought-affected areas from the 1950s.
