基于多光谱和地理加权回归模型的石嘴山城市 土壤有机碳空间分布研究

城市土壤有机碳（SOC）分布受城市建设、工业发展等人为因素的影响表现出明显的空间差 异。为揭示石嘴山市 SOC 受城市化、工业化等人类活动的影响，分别利用普通克里格法（OK）、多元 线性回归克里格法（RK）、遥感反演方法（RS）和遥感-地理加权回归克里格法（RGWRK）预测石嘴 山市 SOC 空间分布。结果表明：石嘴山市 SOC 含量在 1.31 ~ 66.92 g·kg^{- 1} 之间变化，其平均值为 17.61 g·kg^-1。石嘴山市不同功能区 SOC 含量存在显著差异（p < 0.05），具体表现为工业区>医疗区> 商业区>道路>住宅区>公园>农田>科教区；SOC 含量变异系数为 66.27%，呈中等程度变异；其最佳 拟合模型为高斯模型，C₀（/ C₀+C）为 0.02，属于强空间自相关。SOC 与遥感影像波段 DN 值的差值 （B1-B7、B3-B7、B4-B7）和地形因子（高程、坡度、起伏度）之间存在着极显著的相关性（p < 0.01）； 通过对 4 种方法的结果进行对比可知以各波段 DN 值差值与地形因子为输入量，利用 RGWRK 预测 的 SOC 精度最高，相比 OK 精度提高了 10.05%，相比 RK 精度提高了 8.79%，相比 RS 精度提高了 8.92%；研究区 SOC 含量呈北高南低的趋势，工业区 SOC 含量是郊区农田 SOC 含量的 1.92 倍，表明 城区 SOC 含量有富集的趋势。

Spatial distribution of soil organic carbon in Shizuishan based on multispectral and geographically weighted regression model

The distribution of soil organic carbon (SOC) in urban areas is influenced by human factors such as ur? ban construction and industrialization, and thus shows obvious spatial differences. To reveal the impact of human ac? tivities such as urbanization and industrialization on SOC in Shizuishan City, the spatial distribution of SOC in Shi? zuishan was predicted using ordinary Kriging (OK), multiple linear regression Kriging (RK), remote sensing inver? sion (RS), and remote sensing- geographically weighted regression Kriging (RGWRK). The SOC content changed from 1.31 g/kg to 66.92 g·kg^{- 1}, with an average of 17.61 g·kg^{- 1}. There were significant differences in SOC content among different functional areas in Shizuishan (p < 0.05). Specifically, the performance in decreasing order was, in? dustrial areas, medical areas, commercial areas, roads, residential areas, parks, farmlands, scientific and education? al areas. The coefficient of variation of SOC content was 66.27% and there was moderate variation. The best fitting model was the Gauss model, and C₀/(C₀ +C) was 0.02, indicatingstrong spatial autocorrelation. There was a signifi? cant correlation (p < 0.01) between SOC and differences of DN values in different bands of RS images (B1-B7, B3- B7, and B4-B7) and topographic factors (elevation, slope, and relief amplitude). Comparing the results of the four methods demonstrated that SOC predicted by RGWRK was the most accurate, being 10.05% higher than that of OK, 8.79% higher than that of RK, and 8.92% higher than that of RS. SOC content in the northern part of Shizuis? han was higher than the southern part. The SOC content in industrial areas was 1.92 times higher than farmlands, in? dicating that the SOC content in the urban area was enriched.