Abstract:

In order to study and master the evolution of precipitation trend and its periodic change in western Liaoning for making full use of precipitation against drought. The characteristics of annual participation in western Liaoning Province and participation in flood season were analyzed with mathematical statistics method, Mann-Kendall non-parametric test, linear trend fittings, anomaly accumulation and sequential clustering analytical method as well as yearly participation monitoring data from typical weather stations. The results showed that annual participation in western Liaoning Province and participation in flood season had great inter-annual changes, and there was an obvious decline tendency during recent 5 years with climate tendency rate of annual participation of -10.073 mm/10 a, tendency decline of 50.2 mm; climate tendency rate of -17.388 mm/10 a, tendency decline of 86.9 mm. Annual participation is concentrated in period 7 a and 20 a; participation in flood season was concentrated in 8 a, 15-17 a and 20-22 a. Catastrophe point of annual participation was 1980, with 9.4% decline of annual participation; catastrophe point of participation in flood season was 1981, with 13.1% decline of participation. The participation of western Liaoning Province declined year by year, which exacerbated the agricultural drought and seriously influenced the regional development of agricultural economy.