Later this month, Mongolia’s capital, Ulan Batar, will implement a strategy to combat the urban heat island effect that occurs during the summer months while also supplying the community with fresh water. A Mongolian engineering firm, ECOS & EMI, will artificially make naleds, ultra-thick ice sheets that form over frozen streams and rivers, to develop ice shields that will take months to melt. Typically, the ice that forms over rivers and lakes will become no thicker than a meter and upon reaching this thickness, the ice effectively insulates the water and prevents further freezing. A naled forms naturally when cracks develop in the ice and allow water to seep out during the day and then freeze adding additional layers of ice at night. This process results in the formation of naleds up to seven meters thick which in turn take much longer to melt during the spring and summer months.
The idea is to artificially create these naleds on the Tuul river around Ulan Batar by regularly drilling holes in the ice sheets throughout the winter to allow the river water to flow out over the ice, thus thickening the ice sheet. The naleds would then melt slowly into the summer months keeping the city relatively cool while also contributing to the fresh water supply. If the strategy is successful, the company is hopeful to provide a cheap and effective model to keep cities cooler throughout the summer that could be easily replicated worldwide.