# Sand and Dust Storms: Impact Mitigation
## 4 SDS Hazards and Their Mitigation
### SDS Source Mitigation
#### 4.1.3 Controlling Blowing Sand and Mobile Desert Dunes  
The hazards associated with active sand dunes and blowing sand are addressed using engineering techniques involving fences or surface treatments. The measures typically employed, shown in Table 2, are designed to reduce impacts by encouraging the upwind deposition of sand, immobilizing susceptible surfaces, enhancing sand transport through the hazardous area, or deflecting sand movement away from the area to be protected [83]. Specific control measures are chosen depending on the local physical environment, material availability, required life expectancy of the shelter system and its economic feasibility. Reliable climatic information, particularly data on wind and precipitation, is also essential to assessing the local blowing sand hazard [84].  
Fences are deployed extensively in deserts to reduce sand deposition (e.g., along roads and railways) or to reduce wind erosion in an area behind the fence. These artificial structures are constructed using materials such as concrete, metal, plastic, wood, stone, or vegetation and their efficacy in trapping sand depends critically on fence height and porosity [86].  
Attempts to stabilize sand dunes have been undertaken for many decades. Initial, temporary reduction in sand movement can be achieved by covering the sand surface with a much of some kind. Mulching with sprays of petroleum products has been a common practice in parts of the Middle East, but concerns over the release of heavy metals has spurred interest in alternatives. Primary surface stabilization can also be accomplished by stone mulching, the use of chemical stabilizers, biological crusting, or covering the sand with plastic sheets, nets and various forms of geotextiles. A review of historical and contemporary dune stabilization techniques used in the UAE is provided by [PERSON] and [PERSON] [87]. Longer term stabilization can be achieved by planting dunes with adapted grasses, shrubs or trees, and establishing a vegetation cover is often achieved in combination with a much in the early stages. [PERSON] and [PERSON] [88] report that oil much is particularly effective in encouraging seed germination in sand stabilization projects in Iran. In Egypt, and many other countries, treated wastewater is used to irrigate new vegetation until established [89]. Large-scale projects may require specialized aerial seeding from low-flying aircraft, as described by [PERSON] and [PERSON] [90] in Iceland.  
Reed checkboards are widely used in Chinese deserts to reduce surface wind speeds over dunes while the sand is planted with xerophytic shrubs. The process is expensive in economic and labor terms so, in the Taklamakan Desert, [PERSON] et al. [84] explain checkboards are only used along highways that are strategic for the oil industry. The key to establishing vegetation is to select appropriate plant species that will survive the early years of irrigation using often highly saline groundwater. After several decades, soil within the checkerboards typically accumulates elevated levels of silt, clay, carbon  
\begin{table}
\begin{tabular}{c c} \hline
**Control Approach** & **Examples** \\ \hline \multicolumn{2}{c}{Windblown sand} \\ \hline Promote deposition & Ditches; fences; tree belts \\ Enhance transport & Streamlining techniques; creating a smooth texture over the land surface; erecting panels to deflect air flow \\ Reduce sand supply & Surface stabilizing techniques; fences; vegetation \\ Defect moving sand & Fences; tree belts \\ \hline \multicolumn{2}{c}{Mobile dunes} \\ \hline Mechanical removal & Bulldozing \\ Dissipation & Reshaping; trenching; surface stabilization techniques \\ Immobilization by altering aerodynamic form & Surface stabilization techniques; fences \\ \hline \end{tabular}
\end{table}
Table 2: Measures for controlling windblown sand and mobile sand dunes [85].  
and nitrogen that can support a diverse vegetation canopy [91], meaning the technique can also be used for the reclamation of degraded agricultural land [92].