@article{ZhangWielandReicheetal.2011, author = {Zhang, Zhuodong and Wieland, Ralf and Reiche, Matthias and Funk, Roger and Hoffmann, Carsten and Li, Yong and Sommer, Michael}, title = {Wind modelling for wind erosion research by open source computational fluid dynamics}, series = {Ecological informatics : an international journal on ecoinformatics and computational ecolog}, volume = {6}, journal = {Ecological informatics : an international journal on ecoinformatics and computational ecolog}, number = {5}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1574-9541}, doi = {10.1016/j.ecoinf.2011.02.001}, pages = {316 -- 324}, year = {2011}, abstract = {The open source computational fluid dynamics (CFD) wind model (CFD-WEM) for wind erosion research in the Xilingele grassland in Inner Mongolia (autonomous region, China) is compared with two open source CFD models Gerris and OpenFOAM. The evaluation of these models was made according to software technology, implemented methods, handling, accuracy and calculation speed. All models were applied to the same wind tunnel data set. Results show that the simplest CFD-WEM has the highest calculation speed with acceptable accuracy, and the most powerful OpenFOAM produces the simulation with highest accuracy and the lowest calculation speed. Gerris is between CFD-WEM and OpenFOAM. It calculates faster than OpenFOAM, and it is capable to solve different CFD problems. CFD-WEM is the optimal model to be further developed for wind erosion research in Inner Mongolia grassland considering its efficiency and the uncertainties of other input data. However, for other applications using CFD technology, Gerris and OpenFOAM can be good choices. This paper shows the powerful capability of open source CFD software in wind erosion study, and advocates more involvement of open source technology in wind erosion and related ecological researches.}, language = {en} } @article{ZhangWielandReicheetal.2012, author = {Zhang, Zhuodong and Wieland, Ralf and Reiche, Matthias and Funk, Roger and Hoffmann, Carsten and Li, Yong and Sommer, Michael}, title = {Identifying sensitive areas to wind erosion in the xilingele grassland by computational fluid dynamics modelling}, series = {Ecological informatics : an international journal on ecoinformatics and computational ecolog}, volume = {8}, journal = {Ecological informatics : an international journal on ecoinformatics and computational ecolog}, number = {5}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1574-9541}, doi = {10.1016/j.ecoinf.2011.12.002}, pages = {37 -- 47}, year = {2012}, abstract = {In order to identify the areas in the Xilingele grassland which are sensitive to wind erosion, a computational fluid dynamics model (CFD-WEM) was used to simulate the wind fields over a region of 37 km(2) which contains different topography and land use types. Previous studies revealed the important influences of topography and land use on wind erosion in the Xilingele grassland. Topography influences wind fields at large scale, and land use influences wind fields near the ground. Two steps were designed to implement the CFD wind simulation, and they were respectively to simulate the influence of topography and surface roughness on the wind. Digital elevation model (DEM) and surface roughness length were the key inputs for the CFD simulation. The wind simulation by CFD-WEM was validated by a wind data set which was measured simultaneously at six positions in the field. Three scenarios with different wind velocities were designed based on observed dust storm events, and wind fields were simulated according to these scenarios to predict the sensitive areas to wind erosion. General assumptions that cropland is the most sensitive area to wind erosion and heavily and moderately grazed grasslands are both sensitive etc. can be refined by the modelling of CFD-WEM. Aided by the results of this study, the land use planning and protection measures against wind erosion can be more efficient. Based on the case study in the Xilingele grassland, a method of regional wind erosion assessment aided by CFD wind simulation is summarized. The essence of this method is a combination of CFD wind simulation and determination of threshold wind velocity for wind erosion. Because of the physically-based simulation and the flexibility of the method, it can be generalised to other regions.}, language = {en} }