A Study On The Validation Of RWEQ Model In Hebei Bashang

The region of Hebei Bashang is located in the middle of the agro-pastoral ecotone in northern China,where the soil erosion is serious and the ecological is sensitive,and also belongs to a typical wind erosion control area.Crops are still cultivated in traditional farming methods,and farmland distributes at a large plot form.Since 2000 year,there were some projects to be implemented including the projects of controlling sandstorm area for Beijing-Tianjin-Hebei and retrurning farmland into grassland or forestry in Hebei Bashang,and had a huge improvement for local ecology.However,there is a individual distribution among farmland,forestry and grassland,and has a limited protection for farmland wind erisoin by forestry and grassland;At the same time,dry weather and windy day interact with frequent agricultural activities in spring,all of natural and human factors leads to severe wind erosion in farmland,and bring some harm to production and living for local residents furthermore it also has serious impact on the air quality for Beijing,Tianjin and Hebei.Therefore,it is important to strengthen the monitoring and forecasting of wind erosion in Hebei Bashang.In this paper,RWEQ wind erosion model is used to estimate and to verify the potential wind erosion loss in Hebei Bashang.and hope that the RWEQ model is suitable for Bashang region after revised,so that provide some theoretical basis for wind erosion control in China.The results are as follows:(1)For the wind erosion loss during sandstorm event of process,there are some comparison between the measured values and the predicted values during the observation time(10:10~15:10,19th April,2017),the wind erosion prediction by RWEQ at the distances of 130m of downwind(non-erodable boundary)is better than other distances.Except that there is a slight deviation between the predicted and observation values,have a good relationship between them,and show high fit(R~2>0.8,d>0.6),even individual period reached more than 0.85.the results show that the predicted and observation value has a good relationship,and this study can simulate adequately the wind erosion process of storms.(2)For the wind erosion loss during single sandstorm event,by the comparison between the measured and predicted values,the prediction by RWEQ is better for oats residues than tillage farmland.Q(100)is better than Q(50)regardless oftillage or oats residues farmland.The predicting result of Q(50)on tillage farmland was better than that of Q(50)on oats residues,and Q(100)of oats residues farmland was better than Q(100)of tillage.Wind erosion prediction by the RWEQ has a low relationship during the small wind erosion events,and a good relationship during the high wind erosion events.(3)For the loss at different time during wind erosion event,the research shows that RWEQ has better prediction effect on tillage farmland than oats residues by the comparison between the measured and the predicted values.For prediction effect,there are some results:Q(50)is better than Q(100)on tillage farmland,and Q(100)is better than Q(50)on oats residues,Q(50)on tillage farmlandis is better than that of oats residues,Q(100)on tillage farmland better than that of oats residue.For prediction by the RWEQ,there is a better relationship at the slight wind erosion events than that of the strong wind erosion events.In all,RWEQ model has good predicting results in Hebei Bahshang,and great potentiality for application in China,however it need to get much more revisionfor parameter in order to get more accurate wind erosion prediction results.