Mapping SDS sources

Mapping SDS sources

Mapping sources of sand and dust storms helps determine where SDS events may occur, and who might be affected. Module 3, on risk and vulnerability assessment, provides guidance on understanding SDS impacts at the individual and community levels.

Identifying potential SDS sources is the first step in deciding where SDS source control and management efforts are needed. Module 4 provides specific details on the selection of source control and management options once a decision has been made to begin control efforts.

Natural, anthropogenic or a combination of both can change the location and scale of SDS events. As a result, continual observation and monitoring of possible SDS sites is key effective source management. Module 2, on observation, monitoring, forecasting & early warning provides more details on observation and monitoring.

The following sections summarize two different approaches to mapping SDS sources which can be used to support management of SDS sources and events. In most cases, the approaches can be combined to best identify current and possible SDS sources.

SDS source mapping from data on previous SDS occurrences

This approach uses past occurrences of SDS events and similar data sources, drawing on weather data and ground and satellite observations of the presence of SDS. This method is particularly useful for a synoptic understanding of medium to large source areas. Details on this approach can be found in SDS Compendium chapters 8.5.1 and 8.5.2, which include a comparison of advantages and disadvantages of this approach.

The Global assessment of sand and dust storms  provides extensive regional and global information and maps on SDS source areas based on observations. The report is an initial source in identifying whether sources of SDS exist in a location and what locations could be affected during a medium-to-large SDS event.  

Mapping using surface conditions

SDS sources can be mapped by considering the nature of the earth’s surface, including the composition and texture of the topsoil, moisture, temperature and land cover, and how changes in soil surface conditions can lead to SDS events. This method is particularly useful for identifying smaller sources (e.g., small seasonally dry lakes, fields, construction sites), and sites which could emerge due to changes in climate.

SDS Compendium chapters 8.5.3 and 8.5.4 provide background to this approach. Detailed instructions on SDS source mapping based on surface conditions are provided in chapter 8.6.

The SDS Visualization Tool, at right, provides a way to look at possible SDS sources on an annual basis and for the months of January (Winter), April (Spring), July (Summer) and October (Fall).

The division by season recognizes that some SDS sources may only be active during specific times of the year. For instance, some locations experience SDS events during the Spring planting season. Understanding how the potential for SDS events changes over a year’s time is critical for planning for SDS events, including early warning, and implementing source management options.

Further details on the process of identifying possible SDS source locations by surface conditions can be found in the Global Sand and Dust Storm Source Base Map Technical Brief.