2.2.1 Soil moisture monitoring
SM monitor has been established in typical land-cover sites since June
2018. At each site, an array of SM probes (EC-5 probes with a precision
of ±0.1 vol. %; The METER Group, Inc., Pullman, Washington) was
installed horizontally at five depths below the soil surface. According
to previous studies, the SM response depth is limited to the 1-m profile
of each land-cover type after the rainy season (Tang et al., 2018; Wang
et al., 2013; Yu et al., 2015). Thus, we installed an SM monitoring
probe in the 0-1-m profile (10, 30, 50, 70, and 100 cm) to investigate
SM infiltration and the response process affected by rainfall.
Meanwhile, this paper set the 10-cm soil layer as the shallowest
monitoring depth to reveal the difference in surface SM response time
and soil permeability after precipitation as a result of revegetation
(Jin et al., 2018; Lee et al., 2017; Liu et al., 2020).
After installation, the pit was carefully refilled with original soil
material and compacted to the original bulk density layer by layer to
avoid perturbation as much as possible. SM was measured every h and
stored in EM50 dataloggers (The METER Group, Inc., USA). The 1-h SM data
from May 1 to October 31 in the growing season were used to explore the
SM dynamics after rainfall.