人民长江2026，Vol.57Issue(2)：65-73,9.DOI:10.16232/j.cnki.1001-4179.2026.02.008
CUDA架构下流域汇流D8算法并行策略和尺度效应
Parallel strategy and scale effect of D8 algorithm for watershed flow accumulation under CUDA architecture
摘要
Abstract
The flow direction and accumulation algorithms serve as the foundation for hydrological and hydrodynamic simulations on slopes.Implementing the D8 flow accumulation parallel algorithm under the CUDA architecture can effectively accelerate simu-lation speed.The parallel strategy of the algorithm has become a targeted research factor for addressing access conflicts during computation.We optimized the parallelization strategy of the D8 algorithm using the atomicadd function under the CUDA architec-ture and applied it to extract river networks from sub-basins at different spatial scales in the Ganjiang River Basin(including the upper,upper-middle,and entire basin).The extraction accuracy,the acceleration effect and its scale effect were assessed.It demonstrated that the stream network extraction achieved a comparable accuracy to that of the classical algorithm,with relative er-rors in stream length,basin area,and drainage network density all below 0.3%.Under the CUDA architecture,the computation time of the parallel D8 strategy was significantly reduced compared to both the ArcGIS serial algorithm and the Matlab serial algo-rithm,with the order of efficiency as:CUDA D8 parallel<ArcGIS serial<Matlab serial.Additionally,the speedup ratio was proportional to the number of thread blocks and grids.In special,when the number of thread blocks≤128 and>128,the optimal speedup occurred at the number of grid below 1 024 and above 65 536 respectively.A decreasing effect in speedup was observed along with increasing spatial scales,for example the decline amplitude of the ArcGIS speedup ratio for the middle-upper and whole Ganjiang River basin exceeded 20%compared to the upper reach.The parallel strategy of the D8 algorithm can provide a theoretical reference for the parallel computing of hydrological-hydrodynamic models.关键词
流向流量算法/D8算法/CUDA/并行策略/尺度效应/流域水系提取/坡面水文水动力模拟Key words
flow direction and accumulation algorithms/D8 algorithm/CUDA/parallel strategy/scale effect/watershed stream network extraction/hillslope hydrological-hydrodynamic simulation分类
建筑与水利引用本文复制引用
白桦,付哲昊,刘址杰..CUDA架构下流域汇流D8算法并行策略和尺度效应[J].人民长江,2026,57(2):65-73,9.基金项目
江西省自然科学基金项目(20252BAC240135) （20252BAC240135）
江西省水利厅科技项目重大项目(202527ZDKT15) （202527ZDKT15）
国家自然科学基金项目(52269013) （52269013）
江西省水文监测中心对外科技合作项目(2024M1218369900000114) （2024M1218369900000114）
江西省港航建设投资集团有限公司科技项目(2023-YJY-RD02) （2023-YJY-RD02）
