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地处极端干旱区的敦煌市绿洲在气候条件干旱和人类活动加剧的双重压迫下,土壤资源可持续发展面临着严峻的挑战。本研究基于实地调查数据、MODIS-NDVI和DEM数据,在综合分析土壤理化性质的基础上,选取了14项理化指标,利用最小数据集(MDS)方法,从坡向、植被覆盖度和高程3个方面对研究区的土壤质量进行了评价。研究结果表明:不同坡度条件下,土壤质量为阳坡高于阴坡,而阳坡与半阳坡间,阴坡与半阴坡间差异不大;植被覆盖度对土壤质量影响显著,即土壤质量随着植被覆盖度增高而变好;高程对土壤质量的影响具有两面性,随着海拔升高,土壤盐分降低的同时养分含量也在减少;而干旱气候导致土壤盐分偏高,含水量、有效氮和有机质含量显著偏低。此外,研究中基于MDS的方法,引入Norm值以避免仅用因子载荷作为唯一选择标准而导致的部分因子信息被忽略的缺点,在对MDS的可靠性进行验证显示,相关系数检验说明该方法具有很好的可行性。
Dunhuang Oasis is located in an arid region. Under the dual pressures of arid climate and intensified human activities, the sustainable development of soil resources is facing severe challenges. Based on the field survey data, MODIS-NDVI and DEM data, 14 physical and chemical indicators were selected based on the comprehensive analysis of soil physical and chemical properties. From the aspects of slope direction, vegetation coverage and elevation 3 Soil quality in the study area was evaluated on the one hand. The results show that under different slope conditions, the soil quality is higher than the shady slope on the sunny side, while there is no significant difference between the sunny slope and the semi-sunny slope, and between the shady and semi-shady slopes. The vegetation coverage has a significant effect on the soil quality, The quality becomes better with the increase of vegetation coverage; the impact of elevation on soil quality has two aspects. With the elevation increasing, the soil salinity decreases while the content of nutrients also decreases; while the arid climate leads to higher soil salinity, water content and effective Nitrogen and organic matter content is significantly lower. In addition, the MDS-based method and the introduction of Norm value to avoid the shortcomings of partial factor information caused by only using factor load as the only selection criterion. After verifying the reliability of MDS, the correlation coefficient test shows that the method has Very good viability.