Lake Mead, providing Las Vegas with 90 percent of its water needs, has reached its lowest water levels since its original filling and the city has implemented mandatory water cuts of 4.6 percent per person (from 130 gallons in 2012 to 124 gallons in 2013). Similar to identifying crop vulnerability related to North Korea’s drought conditions, vegetation analysis can be used by city managers to evaluate effects of drought and to design, evaluate, and enforce water conservation policies in water limited environments. The map below shows the percent change in vegetation, per pixel, before and after the water cuts. Areas in red have experienced a decrease in vegetation, areas in yellow have remained the same, and areas in green have experienced an increase in vegetation. Toggling layers Edit descriptiondevelopmentseed.org

Toggle OpenStreetMap labels for city locations. View full screen map.

To create this data we used Landsat imagery and NDVI to isolate and then analyze vegetation cover. We showed this last week on a much larger scale with our North Korea drought post. Both municipal managers and humanitarian relief workers can use vegetation analysis to evaluate effects of drought and to design and enforce water conservation or disaster preparedness policies that may help mitigate or avoid disasters.