祁连山西段表土磁化率、色度测量及环境意义
- 收稿日期:
2024-01-02
- 网络出版日期:
2024-05-16
摘要: 研究不同环境沉积物的磁化率和色度的变化机制，对利用该指标进行古气候恢复具有重要意义。通过对我国西北内陆腹地祁连山西段表土磁化率和色度的采样测量，分析了其随降水、气温、海拔的变化特征，并尝试建立了磁化率和色度与气候因子及海拔的函数关系。结果表明：（1）磁化率与年均温、年均降水量呈非线性变化关系，存在一个温度和降水量阈值（~0℃，~300mm），低于该阈值磁化率与其呈反比，反之成正比；磁化率与海拔呈线性负相关关系，在低海拔区域（1600-3300m）尤其敏感。最后通过回归分析建立了祁连山西段磁化率与年均降水量、年均温和海拔的函数关系。（2）色度（亮度、红度、黄度）与气温、降水无明显关系，亮度与海拔呈较显著负相关，且在低海拔地区（1600-3300m）更敏感。（3）比较而言，磁化率比色度更能反映祁连山西段气候及海拔变化信息；对于海拔变化，在低海拔区（1600-3300m）亮度与海拔关系更显著，黄度、磁化率次之；在高海拔区（3700-4300m）红度、亮度与海拔关系更显著。
Magnetic susceptibility and colorimetric measurements of surface soil in the western Qilian Mountains and their environmental significance
- Received Date:
2024-01-02
- Available Online:
2024-05-16
Abstract: It is of great significance to study the variation mechanism of magnetic susceptibility and chroma of sediments in different environments for paleoclimate reconstruction. Based on the sampling and measurement of magnetic susceptibility and colorimetry of the surface soils in the western Qilian Mountains in northwest China, this contribution discussed the variations of magnetic susceptibility and colorimetry in terms of the precipitation, temperature and altitude, and established the functional relationship between magnetic susceptibility and colorimetry and climate factors and altitude. The results show that: (1) there is a nonlinear relationship between magnetic susceptibility and average annual temperature and precipitation, and there is a threshold value (~0℃, ~300mm), below which the magnetic susceptibility is inversely proportional, and vice versa; The magnetic susceptibility is negatively correlated with altitude in particularly at low altitude areas. (2) Chroma (brightness, redness, yellowness) has no obvious relationship with temperature and precipitation, and brightness has a significant negative correlation with altitude, and it is more sensitive in low altitude areas. (3) Compared with colorimetry, magnetic susceptibility can better reflect the climatic and elevation changes in the western Qilian Mountains. For altitude variation, the relationship between brightness and altitude is more significant at low altitude, followed by yellowness and magnetic susceptibility. The relationship between redness and brightness and altitude is more significant in high altitude area.
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