Parallel method for large-area drainage basin extraction

Abstract

The invention discloses a parallel method for large-area drainage basin extraction of massive DEM data. The parallel method comprises the following steps of: step 1, optimally partitioning granularity evaluation; step 2, carrying out swale filling and calculating in accordance with data partitioning and fusion strategies; step 3, carrying out water flow direction parallel calculation in accordance with the data partitioning and fusion strategies on the basis of swale filling results; step 4, carrying out confluence accumulation parallel calculation in accordance with the data partitioning and fusion strategies on the basis of water flow direction data; step 5, setting confluence thresholds and carrying out river network water system parallel calculation in accordance with the data partitioning and fusion strategies on the basis of water flow direction data and confluence accumulation data; and step 6, carrying out sub-drainage basin partitioning parallel calculation in accordance with the data partitioning and fusion strategies on the basis of the river network water system and water flow direction data so as to accomplish the drainage basin extraction. With the adoption of the method, the granularity in data partitioning and an I / O (Input / Output) mechanism are sufficiently considered, and the self data characteristics on the serial algorithm parallel analysis can be considered as well.

Description

technical field [0001] The present invention relates to a watershed extraction parallel technology of a digital elevation model (DEM), specifically a watershed extraction parallel method based on data division, fusion strategy and serial algorithm parallel analysis mechanism for massive DEM data in a large area. Background technique [0002] Digital elevation model products (Digital Elevation Models, abbreviated as DEM) are the most important spatial information data in the geographic information system (Geographical Information System, abbreviated as GIS) geographic database and the core data system for terrain analysis. , transportation, military, water conservancy, agriculture, environment, resource management, planning and tourism and many other fields. For example, in the surveying and mapping department, it is mainly used for 3D terrain modeling, visual domain analysis, engineering earthwork estimation, geometric correction of remote sensing images, etc.; In the field ...

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Problems solved by technology

Jianya Gong (Jianya Gong, Jibo Xie, Extraction of drainage networks from large terrain datasets using high throughout computing[J].Computers & Geosciences,35(2009):337-346.) Using high throughput calculation, using watershed boundaries as data The division strategy extracts watershed networks in parallel from large terrain datasets, but resampling data from a multi-scale perspective to obtain watershed boundary divisions undoubtedly increases computational overhead and cannot be used for load balancing control

[0007] The TAUDEM program of Utah State University in the United States uses the MPICH2 parallel library to realize the parallel extraction and analysis of hydrological information, but it only supports the TIFF data format, and lacks the consideration of system load balancing and computing security and stability generated by the granularity of data division in a parallel environment. and other problems, so this method is often difficult to be directly applied to the actual DEM digital terrain analysis

[0008] The shortcomings of the existing watershed extraction methods mentioned above have brought great difficulties in terrain analysis and engineering applications for large areas, and may even cause decision-making errors in relevant departments in engineering applications such as soil and water conservation and prevention in the Loess Plateau. causing huge economic losses to the country and the people

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