# Sand and Dust Storms: Impact Mitigation
## 4 SDS Hazards and Their Mitigation
### SDS Impact Mitigation  
Actions designed to mitigate the numerous impacts of SDS associated with the transport and deposition of sand and dust are facilitated by a range of monitoring, prediction and early warning initiatives. The entrainment and transport of small particles is monitored using a combination of data from satellites, networks of lidars and radiometers, air-quality monitoring and meteorological stations [98]. All of these sources contribute data to modeling efforts, which enhance our understanding of the processes involved and are used to produce predictions and early warnings. A diverse range of numerical models has been developed, but the prediction of dust events both on the ground and in the atmosphere continues to face a number of significant challenges owing to the complexity of the systems involved [99]. Foremost among these challenges are the relative scarcity of suitable wind erosion observations and the huge range of relevant scales needed to fully account for all of the physical processes related to dust. One national initiative designed to address some of these issues is the National Wind Erosion Research Network established in the USA in 2014 [100]. Nonetheless, numerous methods have been developed to map areas at risk from wind erosion (e.g., [101; 102; 103; 104]) and operational dust forecasts have been developed at a number of centers around the world in recent years, many of these initiatives evolving as part of the WMO's Sand and Dust Storm Warning Advisory and Assessment System (SDS-WAS). Established in 2007, SDS-WAS works as an international network of research, operational centers and user groups such as health, aeronautical, and agricultural communities. More than 15 organizations provide daily dust forecasts using 14 numerical models in different geographical regions [105]. Communicating warnings of imminent dust hazards, advising on health risks and mitigation options, can be achieved through a variety of means, including media coverage and SMS text alerts. Such early warning systems can reduce the impacts of a dust event. In the transport sector, for example, airlines can activate programs to reschedule or cancel flights before passengers arrive at the airport, thus reducing cancellation costs. In South Korea, warnings of yellow dust events (_HuangSa_ in Korean) transported across the Korean peninsula from China and Mongolia are issued by the Korea Meteorological Administration using local media and SMS text alerts issued to users who register on their air quality alert website. There are two levels of notice [106]:  
* Advisory, issued when the hourly mean PM\({}_{10}\) concentration is expected to exceed 400 ug/m\({}^{3}\) for over 2 h.
* Warning, issued when the hourly mean PM\({}_{10}\) concentration is expected to exceed 800 ug/m\({}^{3}\) for over 2 h.  
Reducing impacts also involves assessing vulnerability (identification and mapping of vulnerable populations and infrastructure/facilities), which, alongside future trend scenarios, provides critical inputs to plans to strengthen socio-economic resilience. Vulnerability can be formulated in a number of ways, but all involve three essential parameters: the stress to which a system is exposed, its sensitivity to the impacts of that exposure, and its capacity to adapt to ongoing and future exposure [107]. Our understanding of the vulnerability of landscapes to wind erosion is relatively well-developed and is addressed in detail in Section 4.1, but appreciation of the vulnerability of socio-economic systems to SDS is much less advanced [108]. That said, certain principles identified in other fields also apply to SDS hazards, particularly the understanding that poor people living in the poorest countries are especially vulnerable because they depend on natural resource-based livelihoods that are disproportionately affected by environmental change and have the weakest ability to adapt to impacts, in large part because of their poverty. Poor people in drylands, where SDS are prevalent, are particularly vulnerable.