Overview of the Measures and Techniques Used to Protect Traffic Lines against Shifting Sands in China

Abstract

Shifting sands are one of the main contributors to desertification in China. This paper briefly reviews the measures and techniques which are used to protect traffic lines by stabilizing and fixing sands in the desert and desertification-affected arid and semi-arid areas in north China. We introduce the types and features of these measures and techniques, including mechanical, chemical, and biological measures, and outline how they have been applied in different areas and in different traffic lines over the past six decades, from 1950s to 2010s, taking the Baotou-Lanzhou railway, the Qinghai-Tibet railway, and the Tarim Desert highway as examples Mechanical measures such as erecting sand-retaining wind walls and placing straw checkerboards have proved to be very efficient for stabilizing shifting sands and protecting traffic lines that pass through the desert areas. Chemical measures are not widely used in the current sand fixing systems because of their high cost and potential pollution risks. Biological measures are preferred because they exhibit much better sand fixation performance and longer duration than the former two types of measures despite their relatively high cost. A combination of different measures is usually adopted in some areas to attain better sand-fixing effects. Stabilizing sand dune surfaces with mechanical measures or irrigation from underground water or river if available helps early recruitment of some drought-tolerant plants (xerophytes). We also point out the restrictions for existing sand-fixing measures and techniques and future research orientation. This review has implications for addressing eco-environmental issues associated with infrastructure construction that is part of the Belt and Road Initiative in desert and desertification-affected arid and semi-arid areas in the Mongolian Plateau.