| Cite this article: | 杨昌,王健,李建德,等.土壤表层结皮失水裂缝形态发育规律研究[J].灌溉排水学报,0,():-. |
| YANG Chang,WANG Jian,LI Jiande,et al.土壤表层结皮失水裂缝形态发育规律研究[J].灌溉排水学报,0,():-. |
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| Study on the Regularity of Morphological Development of Cracks in Soil Crust after a Loss of Water |
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YANG Chang1, WANG Jian2, LI Jiande1, XU Feifei1
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1.Institute of Soil and Water Conservation,Northwest A F University,Yangling;2.College of Resources and Environment,Northwest A F University,Yangling
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| Abstract: |
| 【Objective】 To define the cracking rules of cracks on the crust of slope farmland, based on the outdoor test, this study analyses the physical properties of different types of crusts.【Method】At the same time, combined with the image processing function of MATLAB, the development rules of the crack network of different types of crusts were quantitatively analyzed and the change of the morphological characteristics of the crack with the moisture loss of soil was discussed.【Result】The results show that the physical properties of different types of soil crusts have significant differences. Among them, the depositional crust (DC) has the biggest volume weight and the highest content of clay grains, and the content of sand particles of the structural crust (SC) is higher than that of the crust in the transitional zone (TZ) and the depositional crust (DC). The morphological characteristics of desiccation cracks on soil crusts in different parts of the gully area also have significant differences. Among them, the rate of crack area (RC), the length density of crack (LC), and the average width of crack (W_i) meet the following rule: depositional crust (DC)＜transitional zone (TZ)＜structural crust (SC). The difference in the connectivity index (K) of different areas is not significant. The form of the crack difference is mainly affected by the physical properties of crusts, the decrease rate of the moisture content and the initial moisture content. At the same time, the morphological characteristics of cracks on the structural crust are also related to their unique arch-like structure. The relevant analysis shows that RC, LC, and W_i of structural crust and depositional crust increase with the decrease of the moisture content. After the development of the crack is completed, the minimum moisture content of soil of the structural crust is 11.88% and the maximum moisture content of soil of the depositional crust is 20.57%. At the same time, the maximum duration of the development of the crack on the depositional crust is 357 hours.【Conclusion】indicating that the type the crust has an important impact on the development of cracks. The crack of structural crust is the most obvious, and the crack shape of depositional crust is complex and takes the longest time to develop. |
| Key words: crust; cracks; soil moisture content; microtopography |
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