A Study Of Key Techniques In Measuring Water Level And Its Application:An Analysis Based On The Video Data

China has suffered from flood all the year around.With the rapid development of the current science and technology,there have been a lot of breakthroughs in flood prevention.However,it is still difficult to establish stations to obtain the data of water level in some steep terrain.This thesis employs image analysis to obtain the data in every district,which is comprehensive and effectual on some level.This thesis presents a series of research on remote access to water level by image analyzing,and establishes a warning system for this special situation.The main research work is as follows:First of all,this thesis mainly aims at improving the method in acquiring the data of water gauge image,in which both of the thinning algorithm in water gauge image pretreatment of the draft and the extraction algorithm with Hough Transform in image scale gauge are optimized,and the specific experiments prove that the improved part can be implemented.It also indicates that the optimized algorithm has the advantage of time complexity and space complexity.Secondly,this thesis proposes a new method to calculate the water level data from the relationship between the water area and the water level.The first step is to extract the river bank line through edge detection;and the second step is to obtain the data of the specific line by characteristic value matching,which contributes to calculating area below the bank line;finally we can calculate the dynamic water level by fitting the relationship between the area and the water level.Finally,the system design and functional verification of the flood prevention and the warning system are carried out in this thesis.The system is in good operating condition,and the results have assistant decision value to some degree,which can serve as a basis of the plan for flood prevention staff.