Based on the observed temperature, precipitation, wind speed, soil moisture and other basic meteorological data in the north part of Northern China Plain from China Meteorological Administration, three major variables of water cycle: precipitation, soil moisture and water requirement on cropland are calculated. Besides, the water cycle model of cropland in the study area is built together with designed water shortage index to analyze the temporal and spatial variability in water shortage of cropland in the study area by ten-day intervals. Results suggest that the water shortage of cropland in the study area is serious through all growth period. The study area witnesses droughts in most months with sufficient moisture only in the mid July. Spring is the most serious period of droughts on cropland, and the droughts are more severe in central and southern of Hebei Province than that in other areas. Furthermore, the stress of water shortage on cropland in autumn is much relieved compared with that in spring. However, droughts in the northwest part of study area are extremely serious in autumn. Meanwhile, droughts in Hengshui area and western Beijing are the most serious through the whole crop growth stage. Relevant conclusions can provide references to regional water management and irrigation of cropland.

The southwest of China has suffered a great drought since 2009. The authors chose five provinces (Yunnan, Guangxi, Sichuan, Chongqing, Guizhou) as the study area, by using the daily precipitation data from 1970 to 2011 of the 126 meteorological stations in the five provinces, the ten-day precipitation variation rates from 2009 to 2011 for the five provinces were calculated. The results indicated that the precipitation variation rates were negative in most time of the three years. The precipitation reduced at those years, and the decrease of precipitation was most serious in the period from October to March, which are the dry season of this area, therefore, such situation exacerbated the drought degree. The drought had some rules in the spatial distribution that the drought often happened from the Guangxi province first, and then spreaded to the Yunnan and Sichuan provinces, and the drought also ended from the Guangxi province. In addition, through the regress analysis, it was found that the precipitation of the five provinces was influenced by the West Pacific subtropical high and the Tibet plateau barometric pressure, and the effects of the different circulation parameters on the precipitation were not the same.