Beyond the Surface: Understanding Salt Crusts’ Impact on Water Loss in Arid Regions

Younian Wang, Zhiwei Li, Shuaiyu Wang and Chengzhi Li ()
Additional contact information
Younian Wang: College of Ecology and Environment, Xinjiang University, Urumqi 830046, China
Zhiwei Li: College of Ecology and Environment, Xinjiang University, Urumqi 830046, China
Shuaiyu Wang: College of Ecology and Environment, Xinjiang University, Urumqi 830046, China
Chengzhi Li: College of Ecology and Environment, Xinjiang University, Urumqi 830046, China

Land, 2025, vol. 14, issue 10, 1-17

Abstract: Soils in arid regions are characterized by elevated salinity levels. During the process of soil moisture evaporation, salts are transported with water to the surface, resulting in the formation of salt crusts. Although these crusts significantly impact soil moisture evaporation, there is a paucity of systematic quantitative research concerning their formation mechanisms, dynamic evolution patterns, and effects on evaporation. To elucidate the mechanisms by which salt crusts influence soil moisture evaporation, this study conducted evaporation experiments utilizing brine soil columns. Various thicknesses of sand mulching (1 cm, 2 cm, 3 cm, 4 cm, 5 cm, and 6 cm) were applied to the top of the soil columns to generate different forms of NaCl salt crusts. Observations of soil column water evaporation rates, salt crust coverage (SCC), and salt crust morphology were conducted to analyze the effects of salt crust formation on soil water evaporation. The results indicate that the morphology and coverage of NaCl salt crusts significantly influence soil moisture evaporation. A crusty salt crust with high coverage impedes soil moisture evaporation; a patchy salt crust with moderate coverage may promote evaporation; the absence of a crust on the surface has a relatively weak effect on soil moisture evaporation. Nevertheless, the development of ‘salt trees’ within the soil profile can increase soil evaporation. These findings challenge the conventional understanding that “salt inhibits evaporation,” providing essential mechanistic parameters for accurately quantifying evaporation fluxes in saline soils and enhancing regional water cycle models, particularly the module related to atmosphere–soil water vapor exchange.

Keywords: soil evaporation; salt crust; evaporation mechanism; NaCl (search for similar items in EconPapers)
JEL-codes: Q15 Q2 Q24 Q28 Q5 R14 R52 (search for similar items in EconPapers)
Date: 2025
References: View complete reference list from CitEc
Citations:

Downloads: (external link)
https://www.mdpi.com/2073-445X/14/10/2028/pdf (application/pdf)
https://www.mdpi.com/2073-445X/14/10/2028/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jlands:v:14:y:2025:i:10:p:2028-:d:1768506

Access Statistics for this article

Land is currently edited by Ms. Carol Ma

More articles in Land from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().