The cosmic-ray neutron probe (CRNP) is a mesoscale and noninvasive method for measuring soil moisture and has been widely studied and applied. However, studies of its applicability in rocky mountainous areas are still challenging in complex topography and high gravel content. In this study, a field experiment was carried out to assess the applicability of the CRNP for measuring soil moisture in rocky areas of Taihang Mountains of North China. The results showed that the Pearson correlation coefficient and the root mean square error between the soil moisture from CRNP and the drying method are 0.911 and 0.025 m³ m⁻³, respectively, indicating that the CRNP can estimate the average soil moisture well in the study area. Compared with the capacitive sensor, the CRNP overestimated soil moisture when small rainfall events occurred, which was caused by the interception of canopy and litter. The nonlinear weighting method performed better than the linear weighting method in representing average soil moisture within the CRNP footprint. The high gravel content that contained high lattice water content reduced the penetration depth of CRNP. Biomass reduces the accuracy of the CRNP by affecting the neutron intensity. In summary, CRNP can measure soil moisture accurately in rocky areas of the Taihang Mountains, especially in dry environments with low biomass.

中文翻译：

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宇宙线中子探针在太行山岩石区土壤湿度测量中的应用

宇宙线中子探针（CRNP）是一种中尺度、非侵入性测量土壤湿度的方法，已得到广泛的研究和应用。然而，其在地形复杂、砾石含量高的岩石山区的适用性研究仍然具有挑战性。本研究通过现场试验评估了CRNP测量华北太行山岩石地区土壤湿度的适用性。结果表明，CRNP土壤湿度与干燥方法之间的Pearson相关系数和均方根误差分别为0.911和0.025 m ³ m ⁻³，表明CRNP能够较好地估计本研究中的平均土壤湿度。区域。与电容式传感器相比，当小降雨事件发生时，CRNP 会高估土壤湿度，这是由冠层和凋落物的拦截造成的。在表示 CRNP 足迹内的平均土壤湿度方面，非线性加权方法比线性加权方法表现更好。高砾石含量含有高晶格水含量，降低了 CRNP 的渗透深度。生物质通过影响中子强度来降低 CRNP 的准确性。综上所述，CRNP可以准确测量太行山岩石地区的土壤湿度，特别是在生物量低的干燥环境中。