Soldiers of Lixin Police Station of Xigaze Frontier Troop examine likelihood of geological disaster in Zham Town, Xigaze Prefecture, southwest China's Tibet Autonomous Region, April 25, 2017. Zham, once the largest border trade port of Tibet region, is now an empty town. Bordering Nepal, the town was devastated during the 8.1-magnitude earthquake on April 25, 2015. More than 4,250 people were evacuated from Zham four days after the massive earthquake as its geological structure was remarkably changed with possible secondary disasters. Before the earthquake, Zham port cleared about 90 percent of land-borne trade between China and Nepal. [Photo/Xinhua]

Chen Dianzi (1st L) plays a saxophone for his comrades in arms at Gedalin frontier checkpoint in Zham Town, Xigaze Prefecture, southwest China's Tibet Autonomous Region, April 25, 2017. Zham, once the largest border trade port of Tibet region, is now an empty town. Bordering Nepal, the town was devastated during the 8.1-magnitude earthquake on April 25, 2015. More than 4,250 people were evacuated from Zham four days after the massive earthquake as its geological structure was remarkably changed with possible secondary disasters. Before the earthquake, Zham port cleared about 90 percent of land-borne trade between China and Nepal. [Photo/Xinhua]

Frontier soldiers clean a street in Zham Town, Xigaze Prefecture, southwest China's Tibet Autonomous Region, April 25, 2017. Zham, once the largest border trade port of Tibet region, is now an empty town. Bordering Nepal, the town was devastated during the 8.1-magnitude earthquake on April 25, 2015. More than 4,250 people were evacuated from Zham four days after the massive earthquake as its geological structure was remarkably changed with possible secondary disasters. Before the earthquake, Zham port cleared about 90 percent of land-borne trade between China and Nepal. [Photo/Xinhua]

Photo taken on April 25, 2017 shows the empty Zham Town, Xigaze Prefecture, southwest China's Tibet Autonomous Region, April 25, 2017. Zham, once the largest border trade port of Tibet region, is now an empty town. Bordering Nepal, the town was devastated during the 8.1-magnitude earthquake on April 25, 2015. More than 4,250 people were evacuated from Zham four days after the massive earthquake as its geological structure was remarkably changed with possible secondary disasters. Before the earthquake, Zham port cleared about 90 percent of land-borne trade between China and Nepal. [Photo/Xinhua] 

A soldier walks on a road in Zham Town, Xigaze Prefecture, southwest China's Tibet Autonomous Region, April 24, 2017. Zham, once the largest border trade port of Tibet region, is now an empty town. Bordering Nepal, the town was devastated during the 8.1-magnitude earthquake on April 25, 2015. More than 4,250 people were evacuated from Zham four days after the massive earthquake as its geological structure was remarkably changed with possible secondary disasters. Before the earthquake, Zham port cleared about 90 percent of land-borne trade between China and Nepal. [Photo/Xinhua]

Soinam Cering, deputy chief of Gedalin frontier checkpoint, introduces a vegetable greenhouse in Zham Town, Xigaze Prefecture, southwest China's Tibet Autonomous Region, April 25, 2017. Zham, once the largest border trade port of Tibet region, is now an empty town. Bordering Nepal, the town was devastated during the 8.1-magnitude earthquake on April 25, 2015. More than 4,250 people were evacuated from Zham four days after the massive earthquake as its geological structure was remarkably changed with possible secondary disasters. Before the earthquake, Zham port cleared about 90 percent of land-borne trade between China and Nepal. [Photo/Xinhua]