A novel optimization approach to topology checking of pipeline vector data in browser side

The topological relationship of spatial data is essential to GIS data processing and spatial analysis such as in analysis of pipe explosion in gas pipeline network. The existing browser-side JavaScript topology check library is inefficient and even crashes when checking the pipe network topology relationships for large amounts of data. In this paper, we present a topology checking and optimization method for pipeline vector data in browser-side using quadtree. Firstly, an algorithm mechanism that conforms to GIS data is designed based on JavaScript shared memory mechanism, topological check algorithm characteristics, and spatial data high-precision characteristics. Then using a fast rejection experiment and straddle test to realize the browser-side topology checking algorithm, through tolerance setting, improve the inspection efficiency and accuracy, which solves the problem that Turf and Jsts libraries cannot set tolerance. Based on the concept of quadtree spatial index, an optimization method of browser-side quadtree topology checking algorithm(BQTCA) is proposed. Without setting tolerance, the topology check of 114 point data and 1881 line data takes 487 milliseconds, and the efficiency of BQTCA is about 12 times and 39 times higher than that of the well-known public libraries Turf and Jsts, respectively. When the data volume increases to 912 point data and 15048 line data, BQTCA takes 6970 ms, which is about 65 times and 190 times more efficient than Turf and Jsts, respectively. The larger the data volume is, the more pronounced the efficiency improvement of BQTCA. Even when the data volume is so large that Turf and Jsts can- not calculate even crash, BQTCA can still complete the checking calculation. Through experiments, BQTCA can significantly improve the efficiency of browser-side vector pipeline topology relationship inspection under a large amount of data, and meet the commercial application requirements.