Study on forecasting models of grasshopper occurrence area in Qinghai Province

Grasshopper occurrence area，atmospheric circulation characteristics and climate data in Qinghai Province from 1995 to 2006 were collected to analyze the relationship between climate conditions and grasshopper occurrence area, and the multiple regression prediction models of grasshopper occurrence area were built at province, prefecture and county levels. The result showed that subtropical anticyclone intensity index, vortex intensity area and index impacted remarkably on grasshopper occurrence area. The grasshopper occurrence area was increased along with the subtropical anticyclone intensity index. However, it was decreased along with the vortex intensity area and vortex intensity index. During hatching period of grasshopper, the precipitation performed an important role. The relationship between grasshopper occurrence area and temperature was positive remarkably. The temperature showed the positive impact on spawning, winterovering and incubation of grasshopper and lower temperature was the critical factor to inhibit the outbreak of grasshopper. Low air humidity during hatching period was helpful to the outbreak. The models were used to forecast the grasshopper occurrence in 2007 and the result was satisfied and this would serve as a scientific basis for prevention and control of grasshopper disaster in Qinghai Province.