Potential Wind Erosion Simulation Using Different Models In The Agro-pastoral Ecotone Of Northern China

Wind erosion is one of the main processes of soil degradation in arid and semi-arid areas.Quantitative evaluation of wind erosion is an important method to analyze soil degradation.The agro-pastoral ecotone of northern China is a typical area suffering from wind erosion.In this thesis,Revised Wind Erosion Equation(RWEQ),Wind Erosion Predicted System(WEPS),Integrated Wind Erosion Modeling(IWEMS)and National Wind Erosion Survey Model of China(NWESMC),were used to simulate the potential of wind erosion in the agro-pastoral ecotone of northern China from 2000 to 2012.And we further compared the differences between wind erosion model prediction results.The main results include:(1)The simulation results of the models could reflect the potential wind erosion of agro-pastoral ecotone of northern China to some extent.By comparing the model simulation results with the observed wind erosion,it found that there are differences between the simulated results of each model and the measured wind erosion,but the discrepancy between the simulated results and that of each model is different.The WEPS model and the IWEMS model have better prediction results.It found that the simulation results of different models have a similar trend based on the correlation analysis of each model.(2)The potential wind erosion modulus calculated by the four wind erosion models is similar in spatial distribution,which is characterized by the severe wind erosion in Hunshan Dake sands,Horqin sands and Mu Su sands,and the small wind erosion modulus in other places,mainly slight hazard.Although the spatial distribution is consistent,the values of the three sands calculated by the four models are different.For IWEMS and WEPS,the Hunshan Dake sands and Horqin sands suffered the catastrophic wind erosion,the Mu Su sands suffered very severe wind erosion.For RWEQ,Hunshan Dake sands suffered the severe wind erosion,Korqin sands,very severe wind erosion,and Mu Su sands,moderate wind erosion.For NWESMC,moderate wind erosion occurred in Mu Su sands and Korqin sands,severe wind erosion occurred in Hunshan Dake sands.(3)It revealed that the seasonal potential wind erosion were different.The wind erosion modulus of spring is the biggest,then winter,autumn,summer as follow.And the wind erosion modulus of each season calculated by the four wind erosion models were different,mainly the three sands is different.In spring,for IWEMS and WEPS,the Hunshan Dake sands and Horqin sands suffered the catastrophic wind erosion,the Mu Su sands suffered severe and very severe wind erosion.For RWEQ,Hunshan Dake sands suffered the severe wind erosion,Korqin sands,very severe wind erosion,and Mu Su sands,slight wind erosion.For NWESMC,moderate wind erosion germinated in sand.In summer,the result of calculated by four model is similar,mainly slight wind erosion.In autumn,for IWEMS and WEPS,moderate wind erosion occurred in the Hunshan Dake sands,slight wind erosion in the Horqin sands and Mu Su sands.For RWEQ and NWESMC,slight wind erosion occurred in the three sands.In winter,for IWEMS,Hunshan Dake sands sustained catastrophic wind erosion,Korqin sands and Mu Su sands,moderate wind erosion.For WEPS,very severe wind erosion appeared in Hunshan Dake sands,moderate wind erosion appeared in Mu Su sands and Korqin sands.For RWEQ and NWESMC,Hunshan Dake sands are subject to moderate wind erosion,the other sands are subject to slight wind erosion.(4)Although the wind erosion modulus calculated by the four wind erosion models is different,the annual distribution trend of the wind erosion calculated by the four models is similar,all of them show the overall decreasing trend.The trend is that wind erosion modulus calculated by the four wind erosion models in 2001 is the maximum,and then the wind erosion modulus decreases and reaches the minimum in 2011.(5)For the land use,the wind erosion modulus of sands is biggest,then farmland,grassland as follow.The wind erosion modulus of the sands,grassland and farmland calculated by IWEMS is most the biggest,WEPS,RWEQ,NWESMC as follow.It presented that most of grassland suffered slight wind erosion in model RWEQ,WEPS and IWEMS,weak wind erosion in NWESMC.Most of farmland were subject to slight wind erosion in four models.For RWEQ,the very severe wind erosion mainly occurred in sands.For WEPS and IWEMS,catastrophic wind erosion occurred in sands.For NWESMC,moderate wind erosion occurred in the sands.