Basin Flood Simulation Based On Spatiotemporal Variable Source Mixed Production Flow Model

Since the 21st century,China has been affected by global warming,extreme rainstorm events are frequent,causing serious injuries to people’s lives and property losses,but also restricting China’s social and economic development,flood disaster early warning and prevention has been highly valued by the domestic and foreign society,flash flood disaster monitoring and prevention and related research are its important content.The flood disaster in the Ussuri River Basin has the characteristics of rapid disaster and strong suddenness,and is currently one of the relatively weak places in China’s flood disaster prevention and control.Exploring the mechanism of production and flow in the Ussuri River Basin and establishing an accurate model for flood simulation are very important steps in flood prevention and disaster reduction,which can effectively improve China’s flood disaster prevention capabilities.The production and flow process of small watershed is affected by many factors such as rainfall size distribution,topography and landform,land use,soil texture,vegetation and underlying surface,and the key problems to be solved are to study the main production mechanism,model modeling method and accuracy of distributed model in the Ussuri River Basin.At the same time,due to the complex topography and rainfall distribution of the river basin,the multi-source mixing characteristics and temporal and spatial discretization of the production flow mechanism,how to quickly identify the production flow mechanism of the river basin is an important challenge in the modeling of distributed hydrological models,which has an important impact on the speed and accuracy of its modeling.This study aims to study the flood disaster mechanism in the Ussuri River Basin of Heilongjiang Province,and uses the spatiotemporal variable source mixed production flow model for modeling and parameter determination,and the main research contents are as follows: 1.Based on the high-precision hydrological data of the Ussuri River Basin,the division method of the hydrological response unit and its relationship with the characteristics of the underlying surface were studied.2.Research on the modular modeling method and production flow mechanism based on spatiotemporal variable source mixed production flow model;3.Based on MATLAB,ARCGIS and other software to summarize and sort out hydrological data,calculate unit division and basin data split,complete the modular modeling of the small watershed of the Ussuri River through the spatiotemporal variable source mixed production flow model,and determine the parameter rate.The results achieved are as follows: 1.Based on the dataset of "National Flash Flood Disaster Investigation and Evaluation" and high-precision DEM data,this study proposes the division standard and division method of hydrological response unit by referring to relevant research and data results at home and abroad since the 50 s of last century,and extracts the characteristics of the underlying surface,which provides a theoretical basis for the modeling of distributed hydrological model through the characteristics of the response unit and the underlying surface;2.The relationship between soil water content and infiltration is calculated in real time,the infiltration rate of the calculation unit is compared with the infiltration capacity of its underlying surface,the conversion of superpermeable production flow and storage production flow is realized,the main production flow mechanism of the watershed geomorphological response unit is determined by the relationship between the characteristics of the underlying surface and the production flow mechanism,and the data is integrated in the modular hydrological model software FFMS to realize the rapid construction of modular and visualized distributed hydrological models;3.After data preprocessing and accurate division of computing units,the distributed model modeling work of the Ussuri River Basin was carried out through the spatiotemporal variable source mixed production flow model,and then three typical floods were selected for model rate determination,and by adjusting the model parameters,the production flow coefficient and model accuracy reached the expected standard,which proved that this model can provide an effective theoretical basis for flood disaster early warning in China.In this study,the Ussuri River Basin in Heilongjiang Province was studied based on high-precision topography and geomorphology and hydrological data,and the mechanism,method,production and flow mechanism of the watershed and model modeling were studied.The research results provide effective technical support for flood forecasting and early warning in China,and provide a certain reference for heavy rain and flood warning in other parts of China.