基于图形绘制技术的河床冲淤演变定量分析方法

针对常规河床演变分析方法的不足,对基于图形绘制技术的河床冲淤演变时空定量分析方法进行了深入研究,利用柱体叠加的思想,以及栅格网技术,对冲淤部位和冲淤量值的确定方法提出了新的见解. 工程实践表明,建立在实测数据基础上的栅格网法,具有计算精度高、冲淤演变区域确定准确、计算速度快等特点;等值线法实则也采用了栅格网法的计算思想,计算精度和演变范围的确定精度完全取决于等值线的密集、准确程度;实践表明,0.5 m间隔的等值线可以满足冲淤演变计算和分析的精度要求,在缺乏实测数据的情况下,该法是一种较好的冲淤定量分析方法.

Research on determination of quantitative analysis for riverbed sedimentation amount

A new method based on graph plotting is put forward; because the advanced graph the ability of qualitative analysis and quantitative analysis of this method is enhanced because the advanced graph technology in adopted. According to graph technology, using the thought of triangular prisms piled up, and grid-net technology, the new methods for the quantity and part of sedimentation are introduced. Based on graph technologies, sedimentation amount of riverbed evolution quantity is determined through the methods of grid-net or contour map. Because grid-net method can fulfill a comparison between two terms riverbed data in the same position, using method of reservoir capacity determination, not only the change of reservoir capacity in whole research area is got, but also the change in interesting small area can be determined; at the same time, some detail information can be drawn out from grid-net data. So, using the technology, full-scale quantitative analysis and qualitative analysis can be fulfilled. Contour map is as an important tool for determination of sedimentation quantity when there are no original data. According to research and test, the method is thought to have characters of high accuracy and fast speed. The accuracy of determination of sedimentation quantity is affected by representation of contours. Namely, if contour map is big scale, and the interval of contours is dense and accurate, contours can meet with requirement for parameters determination. Otherwise, accuracy of parameters determination is ensured difficultly. In general, it is thought to be appropriated that contour interval is (0.5) meter.