Ed Jones / AFP - Getty Images

A view of the Yueyaquan Crescent Lake, near the city of Dunhuang in China's northwestern Gansu province, on May 12, 2013.

Ed Jones / AFP - Getty Images

Camels at rest in the desert near Dunhuang.

Ed Jones / AFP - Getty Images

A man smokes a cigarette near the Yueyaquan Crescent Lake.

Ed Jones / AFP - Getty Images

A Muslim food vendor cooks at his stall in Dunhuang.

Ed Jones / AFP - Getty Images

A guide leads camels near the Yueyaquan Crescent Lake.

Formerly a Silk Road hub and center for trade between China and the West, the city of Dunhuang relies heavily on tourism and features a number of historic sites dating back to the Han Dynasty. The city in China's northwestern Gansu province has an arid climate and is surrounded by sand dunes, a result of increasing desertification.

-- Agence France-Presse

Roberto Schmidt / AFP - Getty Images

A man and child ride a donkey along a road leading into the small town of Baharak in Northeastern Afghanistan in the late afternoon on October 6, 2012.

The town is located in a fertile valley which is fed by the Kokcha river and is ringed by rugged arid mountains to the north and south. The province of Badakhshan, which shares borders with Tajikistan, China and Pakistan, is mostly inhabited by ethnic Tajik, Uzbek and Kyrgyz people.

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Slideshow: Afghanistan: Nation at a crossroads

Aref Karimi / AFP - Getty Images

More than ten years after the beginning of the war, Afghanistan faces external pressure to reform as well as ongoing internal conflicts.

Launch slideshow

Photographer David Gray has been traveling across a small part of Mongolia, which is the least densely populated country on the planet according to figures cited by Reuters. The population of just 2.7 million is spread across an area three times the size of France, with two-fifths of Mongolians living in rural areas. 

David Gray / Reuters

Horses graze on grasslands south-west of the Mongolian capital city Ulan Bator on April 4, 2012.

David Gray / Reuters

A painting of the former Mongolian Emperor Genghis Khan hangs from the wall of a mining hut located around 62 miles north of Ulan Bator on April 5, 2012.

David Gray / Reuters

A frozen river is seen next to a group of houses located on the outskirts of the Mongolian capital city of Ulan Bator on April 3, 2012.

Reuters examines the political situation in Mongolia ahead of parliamentary elections in June: 

Mongolia sits on vast quantities of untapped mineral wealth, the exploitation of which is likely to turn it into one of the world's fastest growing economies over the next decade. 

But political uncertainty worries investors. One of the parties in Mongolia's shaky coalition government said it would pull out before the vote, and politicians are under constant pressure to be seen to getting a good deal for the country from resources investors.

The priority for Mongolia is the development of its tiny economy, and foreign investors want to know if the government can create a stable legal environment while handling the pressures exerted by impatient citizens as well as its two giant neighbours, Russia and China. Read more.

David Gray / Reuters

A herder stands on a hill overlooking grasslands south-west of Ulan Bator on April 4, 2012.

David Gray / Reuters

A dog sits at the door to a house in a small township located on grasslands south-west of Ulan Bator on April 4, 2012.

David Gray / Reuters

A woman performs a water displacement test to determine the purity of some gold that was brought in by small-scale miners at a processing plant north of Ulan Bator on April 5, 2012. The International Monetary Fund estimates Mongolia's GDP could grow as much as 10 percent this year, helped by rising gold prices but there is concern over environmental standards in the mining industry.

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Chinafotopress via Getty Images

Green terraced fields after heavy rain on June 6 in Guiyang, Guizhou Province, China. According to the China Meteorological Administration on Monday, heavy rain will affect parts of eastern and southern China over the next three days. Heavy rainfall has alleviated the drought in the middle and lower reaches of the Yangtze river. But many parts of Guizhou, Jiangxi and Hunan provinces have suffered flooding since Saturday.

Reuters reports from Beijing:

A drought that has gripped parts of central and southern China has retreated after downpours over the weekend that brought deadly flooding to one area, official media reports said on Tuesday.

Parts of China along the Yangtze River basin and nearby have been enduring their worst drought in 50 years or more, with rainfall 40 to 60 percent less than normal over recent months, damaging crops and cutting power from hydroelectric dams.

Some dry areas enjoyed rains of up to 80 millimetres (3.1 inches) between Friday and Monday, the People's Daily said.

In the southwest province of Guizhou, the easing of drought swung to flooding that killed 9 people and left 13 missing in Wangmo County. Torrential rains there overwhelmed the local river and flooded the county seat and other towns, forcing 6,000 people to move, Xinhua news agency reported.

Related content:

• Chinese drought turns lake into a dry ocean of green grass
• Drought continues in central and southern China
• Couple struggles to navigate what is left of irrigation canal

Mitch Epstein has been awarded the 2011 Prix Pictet, an award for photography that tackles social and environmental issues. Epstein was nominated for his series American Power, which studies the different ways in which the country produces and uses energy and how that impacts on the landscape and environment.

Mitch Epstein via Prix Pictet

Amos Coal Power Plant, Raymond City, West Virginia. 2004.

Mitch Epstein via Prix Pictet

BP Carson Refinery, California. 2007.

Epstein says the project "asks everyone to look harder at their daily relationship to energy" and seeks to instigate a discussion about "the direction of American power. It is an opportune, if not crucial, moment in the history of the United States to discuss what it has done and could do with its natural resources, wealth, and might, but also its brain power, power of imagination, and power of community."

Mitch Epstein via Prix Pictet

Biloxi, Mississippi. 2005.

Mitch Epstein via Prix Pictet

Hoover Dam and Lake Mead,
Nevada/Arizona. 2007.

Read more about the work at Epstein's American Power website and at Prix Pictet.