Flood level is important information for flood control decision and flood loss evaluation.Based on the principles of trend surface analysis and field survey of flooded areas of Mabu Town in Wenzhou City during typhoon Matsa,a simple and quadratic trend surface model of flood level was developed and validated.The results showed that the prediction of the model matched the field data of the flood levels quite well,indicating the strong coefficients of determination of 0.95 and 0.96 for the first and second order surface simulation(p0.01),respectively.The average absolute error of the first-order model was 0.1 m in validation,while that of the second-order model was 0.3 m lower.