Abstract: Wind erosion is one of the major ecological and environmental problems in the arid and semi-arid steppe areas of northern China， which not only affects the stability of steppe ecosystems， but also exacerbates the problems of land degradation and desertification， and is a key factor affecting agricultural production and ecological security in the region. In this study， different grazing gradients were selected to investigate the relationship between grazing intensity and wind-sand flux and wind-erosion influencing factors， and to optimize the predictive ability of wind-erosion model. This experiment was carried out in a desert steppe grazing trial site through 4 treatments of control （CK）， light grazing （LG）， moderate grazing （MG） and heavy grazing （HG）， by the randomized block design with three replications. Based on the observations of wind and sand fluxes and wind erosion influence factor indicators of different grazing gradients in 2021-2022， some empirical parameters in the RWEQ model were calibrated and the calculation method of critical sand initiation wind speed was optimized. The results showed that the optimized RWEQ had a good fit between the predicted and measured wind-sand fluxes under different grazing intensities in 2022 with d=0.67， and R² of 0.9365， P<0.01， and the correlation between the predicted and measured wind-sand fluxes was good. The predicted results of the optimized RWEQ in the experimental area of different grazing intensities in desert steppe have a greater reference value for formulating reasonable grazing intensities， planning grazing time， guiding vegetation restoration， and assessing the impacts of grazing on ecosystem health.

Key words: Desert steppe, soil wind erosion, grazing intensity, RWEQ model

摘要： 风蚀是中国北方干旱半干旱草原区主要的生态环境问题之一，风蚀不仅影响草原生态系统的稳定性，还会加剧土地退化和沙漠化问题，是影响该区域农业生产和生态安全的关键因素。本研究选择了不同的放牧梯度，旨在探究放牧强度与风沙通量及风蚀影响因子之间的关系，并优化风蚀模型的预测能力。本试验在荒漠草原放牧试验地开展，采用随机区组设计，有不放牧（CK）、轻度放牧（LG）、中度放牧（MG）和重度放牧（HG）4个处理，每个处理3次重复。基于2021-2022年不同放牧梯度风沙通量及风蚀影响因子指标的观测，对RWEQ模型中部分经验参数进行校准和对临界起沙风速的计算方法进行优化。研究结果表明：优化后的RWEQ在对2022年不同放牧强度下的风沙通量的预测值和实测值的拟合较好d=0.67，R²的拟合度为0.9365，P<0.01，预测与实测风沙通量相关性较好。优化后的RWEQ在荒漠草原不同放牧强度试验区的预测结果对制定合理的放牧强度、规划放牧时间、指导植被恢复、评估放牧对生态系统健康的影响具有较大的参考价值。

关键词: 荒漠草原, 土壤风蚀, 放牧强度, RWEQ模型