Shuang Dong

and 3 more

Dried soil layer (DSL) is a common phenomenon forms by soil moisture deficiency in the Chinese Loess Plateau (CLP). In order to reveal the temporal stability and elimination degree of DSLs, we obtained the 19 occasions data of soil water content (SWC) at 15 observation sites in a typical slope-gully unit. The available soil moisture (ASM) and DSL were estimated by representative sites which determined through the temporal stability method, and then assessed the reliability of simulation equations between representative locations condition and mean conditions of the study area. Results show that: (1) The temporal dynamics of DSL were characterized with somewhat complexity. The ASM within the DSL (DSL-ASM), ASM within the sandwiched dried soil layer (SDSL-ASM) and quantitative index (QI) varied within the range of 2.75%–3.11%, 2.98%–4.22% and 0.254–0.356, respectively. (2) The possibility of development and recovery for DSL and SDSL in deep layers were less than that in surface layers. The maximum depth of DSL (DSLMD) was significantly and negatively related to the SDRD of DSL-ASM, the maximum depth of SDSL (SDSLMD) was negatively related to the SDRD of SDSL-ASM. (3) The prediction results of ASM above 300 cm depth were more accurate than other layers ( R 2=0.89). The DSL-ASM has a more prediction accurate than SDSL-ASM and QI. On the analysis of the time stability characteristics of ASM and dried soil layers, A2 and C3 can better represent the mean conditions of ASM at the depth of three and four soil layers, respectively. C2, A1 and A1 can better represent the average levels of DSL-ASM, SDSL-ASM and QI, respectively ( R 2=0.43, 0.14 and 0.18). (4) The restoration degrees of DSLs mainly showed no elimination and slight elimination, the DSLs cannot be completely eliminated within a short time. Scientific regulation of soil moisture can alleviate the formation and development of DSLs a certain extent, and provide the possibility for DSLs restoration.