Spatiotemporal Distribution of Soil Moisture and Salinity in the Taklimakan Desert Highway Shelterbelt

Yuan Huang,Jianguo Zhang,Xinwen Xu,Ying Zhao,Yongdong Wang,Congjuan Li

doi:10.3390/w7084343

Abstract

Salinization and secondary salinization often appear after irrigation with saline water. The Taklimakan Desert Highway Shelterbelt has been irrigated with saline ground water for more than ten years; however, soil salinity in the shelterbelt has not been evaluated. The objective of this study was to analyze the spatial and temporal distribution of soil moisture and salinity in the shelterbelt system. Using a non-uniform grid method, soil samples were collected every two days during one ten-day irrigation cycle in July 2014 and one day in spring, summer, and autumn. The results indicated that soil moisture declined linearly with time during the irrigation cycle. Soil moisture was greatest in the southern and eastern sections of the study area. In contrast to soil moisture, soil electrical conductivity increased from 2 to 6 days after irrigation, and then gradually decreased from 6 to 8 days after irrigation. Soil moisture was the greatest in spring and the least in summer. In contrast, soil salinity increased from spring to autumn. Long time drip-irrigation with saline groundwater increased soil salinity slightly. The soil salt content was closely associated with soil texture. The current soil salt content did not affect plant growth, however, the soil in the shelterbelt should be continuously monitored to prevent salinization in the future.

Highlights

In arid and semiarid regions, water scarcity is a serious and chronic environmental problem threatening the ecosystem [1]
The large coefficient of variation (CV) values were obtained for soil moisture (196.99%) and electrical conductivity (EC) (107.00%), indicating a strong spatial variation
Soil moisture gradually reduced, which was lower at the northwest than at the southeast

Summary

Introduction

In arid and semiarid regions, water scarcity is a serious and chronic environmental problem threatening the ecosystem [1]. To overcome this shortage, lower quality water is widely used [2,3]. A highway was built from north to south across the Taklimakan Desert in 1997. A shelterbelt was planted along both sides of the highway in 2003, to limit sand drift into the highway [5]. The moving dunes have been successfully stabilized on both sides of the highway for more than ten years. The highway shelterbelt is irrigated with underground water

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Conclusion