【摘要】 作为典型的半干旱沙区,科尔沁左翼后旗(简称"科左后旗")土地退化严重,土壤风蚀程度较强,有针对性地调整土地利用结构,有助于农牧交错区社会经济和生态环境的可持续发展.采用修正风蚀方程(RWEQ)模拟科左后旗的风蚀状况,并结合CA-Markov模型和当地风蚀状况及区域相关规划,设定了延续现有发展态势的历史发展情景、在全区域内开展风蚀治理的全域治理情景和依照区域风蚀特征实施治理的分区治理情景3种未来可能的发展情景,基于Dyna-CLUE模型模拟各情景下科左后旗2020年的土地利用格局.结果表明:①2010年科左后旗的平均风蚀量为33. 86 t/(hm2·a),风蚀程度较为严重,并且具有明显的西高东低的空间差异.②采用Dyna-CLUE模型模拟2010年土地利用空间分布结果的Kappa指数达0. 921,模拟效果良好.③与2010年相比,历史发展情景下,2020年科左后旗荒漠化趋势更加严重,未利用地面积将增加33. 76%,草地退化明显;全域治理情景下,风沙治理取得了一定成效,70. 30%的未利用地得到治理,其中分别有32. 32%和32. 52%转化为林地和草地,水域也得到一定恢复,面积将增加5. 01%;相比于全域治理情景,分区治理情景下高风蚀地区有更多的未利用地得到治理,低风蚀地区耕地面积将增加4. 68%,进行风沙治理的同时也在一定程度上保护了耕地.研究显示,Dyna-CLUE模型在我国农牧交错区具有较好的土地利用格局的模拟能力,采取积极的风沙防治措施可以大幅提高当地的林地和草地面积,而采取有针对性的分区域治理政策在进行风沙治理的同时也可有效地保护耕地.更多还原

【Abstract】 Horqin Left Back Banner is located in a typical semi-arid sand area with heavy soil degradation and strong wind erosion.From the perspective of wind erosion prevention and land protection,optimization of land use structure will help regional sustainable development in terms of social,economic and ecological aspects in the interlaced agricultural and pastoral areas.This study applied the Revised Wind Erosion Equation(RWEQ)model for simulating wind erosion in the case area of Horqin Left Back Banner.Three future scenarios,considering historical development,whole area administration and regional administration,were development based on the CA-Markov model,local wind erosion conditions and related regional planning.The Dyna-CLUE model was further used to simulate land use patterns of Horqin Left Back Banner in 2020 for each developed scenario.The model results suggested that:(1)The wind erosion of Horqin Left Back Banner was intense with a clear spatial heterogeneity in the year of 2010,with an average value up to 33.86 t/(hm~2·a).(2)The Kappa index of the simulated results for the year of 2010 was about 0.921,indicating that the Dyna-CLUE model has a good simulation performance.(3)The results for the historical development scenario suggested a serious trend of desertification and grassland degradation in Horqin Left Back Banner,and in particular the area of desert land was found to increase by 33.76%.The whole area administration scenario indicated an effective achievement in wind erosion control.70.30%of the unused land was reclaimed,where32.32%and 32.52%were converted to woodland and grassland,respectively.The water and wetlands areas were also restored,with an increase in total area by 5.01%.Compared to the whole area administration scenario,the regional administration scenario suggested that the reclaimed area of unutilized land in high wind erosion areas was even larger,meanwhile the area of arable land in low wind erosion areas was found to increase by 4.68%.Overall,this work suggested that the Dyna-CLUE model is robust in simulating land-use patterns for agricultural and pastoral ecotones in China;active sand prevention and control measures can significantly increase local forest land and grassland areas,and targeted sub-regional governance policies can effectively protect cultivated land while harnessing wind erosion.更多还原