黑土型退化草地时空格局遥感监测

Spatio-temporal monitoring of black soil land degraded grassland by remote sensing

准确及时地了解黑土型退化草地的时空分布特点,对祁连山地区草地退化修复治理具有重要意义。本文选取祁连县野牛沟乡西北部区域作为研究区,基于Landsat 8 OLI影像,结合地理国情监测成果,尝试利用分场景的决策树分类方法提取黑土型退化草地范围,并对比分析2014—2019年黑土型退化草地的时空变化特征。结果表明,多场景的决策树分类方法对黑土型退化草地监测具有很好的适用性;2014—2019年,研究区北部部分区域缓坡地和中部滩地黑土型退化问题有所好转,西部和西北部缓坡地黑土型退化问题有进一步恶化的趋势;好转草地主要以人工干预为主,恶化草地可能是受水热空洞效应、鼠害等多种因素的影响。

Accurate and timely monitoring the spatio-distribution characteristics of black soil land degraded grassland is of great significance to the restoration and management of grassland degradation in Qilian Mountains.Based on Landsat 8 OLI images and threshold method,we try to extract the scope of black soil land degraded grassland,and analyse spatio-temporal variation from 2014 to 2019 in northwestern part of Yeniugou township,Qilian county.The results show that the scheme has a certain reliability.During 2014 and 2019,the black soil land degraded grassland has improving trend in northern gentle slope part and central flat parts,and worse trend in western part and northwestern gentle slope part.The improving grassland depends on human intervention,and the deterioration grassland may be affected by many factors,such as water heat hole effects,rodent damage and so on.