Research On Parallel Computing For Groundwater Flow Spatial Data Simulation

Rational use and quality monitoring of the groundwater is a major event of people’slivelihood. Research on the groundwater flow system is an important tool to achieve quantitativeevaluation and the forecast of groundwater resources. It also provides decisive supports for thesustainable use of groundwater resources. The groundwater flow pattern reflects the hydraulicheads change with the time and space. Therefore, research on the groundwater flow system canbe attributed to study the groundwater flow spatial data. The continuous development of thegroundwater flow system requires grid granularity finer and study area larger. The traditionalsimulation of groundwater flow spatial data makes simulation time too long and can not meet theactual demands. Emergence of parallel computing technology provides a very effective means tosolve data-intensive computing tasks. Therefore, the purpose of this thesis is using parallelcomputing technology to achieve a fast and efficient simulation of groundwater flow spatial data.This thesis focuses on the parallel finite difference numerical simulation of groundwaterflow spatial data. Based on the relevant theories and existing parallel research on groundwater,this thesis proposes appropriate parallel numerical simulation strategies of groundwater flowspatial data for different parallel computers. The main innovations of the thesis are as follows.I. This thesis proposes a MPI/OpenMP hybrid programming model based on overlappingdomain decomposition algorithm to parallelize the simulation of groundwater flow spatial data.That means dividing a large-scale groundwater flow spatial data problem into several smallsub-problems. This parallel strategy achieves a two-level parallelism granularity includingprocess and thread. For a numerical model with grid size60×100×100, the experimental resultsyield a speedup of3.31for four sub-regions on a SMP cluster with two nodes.II. This thesis proposes a GPU-based parallel simulation strategy of groundwater flowspatial data. That means solving the numerical model of the groundwater flow spatial data onGPU. On parallel platforms support GPU general-purpose computing, this paper compares theparallel performance of three parallel strategies which are groundwater flow spatial data basedon OpenMP, MPI/OpenMP and GPU. The experimental results yield that the GPU-based parallelstrategy has the best parallel performance. III. This thesis proposes a parallel MODFLOW based on a linear solver CUSP. That meansusing linear solver CUSP instead of the iterative methods in MODFLOW. This thesis makes aperformance comparison between parallel MODFLOW based on OpenMP and parallelMODFLOW based on CUSP. For the TWRI_LARGE numerical model, the experimental resultsyield the maximum speedup of5.31for the OpenMP-based MODFLOW when the simulation isparallelized by eight threads. On a computer with one GPU, the experimental results yield thespeedup of10.6for the CUSP-based MODFLOW.