A bright salt pan to a wet and lush landscape – the United States National Aeronautics and Space Administration (NASA) recently captured images depicting the wet and dry cycles of Etosha Pan in Africa’s Namibia through the year. Though unusually dry weather left Etosha Pan without water in December 2019, just two months later a surge of rain had refilled much of it. By late August 2020, the salt pan had mostly dried again, aside from some water near the mouth of the Ekuma River.

The Etosha pan is hollow in the ground, wherein water may collect or in which a deposit of salt remains after the water has evaporated. The 120-kilometre-long dry lakebed and its surroundings are protected as Etosha National Park, Namibia’s second-largest wildlife park. Etosha National Park supports large populations of elephants, lions, rhinos, and several other animals. The dry season is one of the best times for visitors to see animals because they often congregate around shrinking bodies of water.

According to NASA Earth Observatory, the salt pan receives the most rainfall. Almost all of the 46 centimetres (18 inches) of rain that falls in Etosha National Park each year arrive between October and March. The influx of moisture, a boon for the wildlife, completely transforms the landscape. It greens parched grasslands, replenishes ephemeral streams and watering holes, and sometimes pools enough to cover a flat basin with a layer of water that extends for thousands of square kilometres. When the rains slow and cease during the dry season (April through September), any water in the basin slowly evaporates, depositing salt and other minerals on the land surface in the process. Over time, this cycle of flooding and evaporation has built up a mineral-encrusted surface called a salt pan. In fact, the striking white surface of the salt pan is what originally earned Etosha Pan its name. In the language of the local Ovambo people, Etosha means “great white place.”

However, in January 2020, its landscape was transformed by a heavy spell of rain. The green regions depict living vegetation — sparse or thick. The darker shades of blue signify deeper water. By August 31, 2020 (as shown in the image below), the salt pan had mostly dried again, aside from some water near the mouth of the Ekuma River. The red spots are burn scars from recent fires. The satellite imagery showed the scar closest to the Ekuma River burned for a few days beginning on July 13, 2020.

Fires would usually come after a wet spell produced a surge of vegetation growth, which would later be rendered dry and catch fire. However, with evidence piling up that needed occasional fire to keep the ecosystem healthy, park managers started using it as a tool in 1981. With time, as the system evolved, lightning-ignited blazes have been allowed to burn more frequently with prescribed burns that create a patchwork of natural fire breaks. These managed burns also prevent the build-up of excess fuel, lowering the severity of future wildfires.