Relationship between the area suffered agricultural flood disaster and rainstorm in Tangshan

Using data of the annual planting area and the area suffered agricultural flood of each county from 1985 to 2014 provided by Tangshan Statistical Bureau, as well as daily precipitation data from 11 meteorological stations in Tangshan, the trend analysis and polynomial statistical regression were used to analyze the spatial and temporal characteristics of agricultural flood disasters in Tangshan and their relationships with rainstorm.The results show that the area suffered flood disaster in Tangshan has a slight downward trend, though it cannot pass the significant test, which is consistent with the changing trend of the number of annual rainstorm days.The degrees of flood disasters in each county are mainly mild to moderate, accounting for 80% to 100% of the total number of flood disasters.The occurrence of flood disaster in Tangshan is related to the annual rainstorm (R = 0.78), though it cannot pass the significant test.The area of disaster is significantly correlated with the number of annual rainstorm days (R = 0.83, P < 0.01).Rainstorms in years with above medium level flood disaster have the following characteristics:average rainstorm days are 4-6 days, the number of heavy rainstorm days of 80% county stations is 0.7-1.5 days, and accumulated amount of 60% of rainstorm is more than 300 mm.In addition, factors such as regional planting structure, topography and water system distribution are also important aspects causing the occurrence of flood disasters.