by Xinhua writers Fu Shuangqi, Zhang Mimi and Fan Yongqiang

    URUMQI, Dec. 6 (Xinhua) -- Tanned and wiry, Officer Zhang Min looks like a man who's spent years in the open. He's also been witness to vast changes in northwestern Xinjiang.

    "Every inhabited place has gone through dramatic changes," saidZhang, an engineer of the army mapping service in Xinjiang since 1981.

    Comparing today's map with that of three decades ago, the differences are stark.

    The Karakoram Range still stands and the Taklimakan Desert never shifts, but so much else has changed. Populous towns and cities replaced scattered villages, straight highways replaced winding paths, reservoirs replaced wells and small pools enclosed by mud dams to collect rainwater.

    "Our maps are always catching up with the changing reality," Zhang said. "The helicopter corps turns to us so often because maps quickly become outdated."

    As a member of the field squad that mapped Hotan City in southern Xinjiang in 1997, he was shocked that he could no longer find the way to the city in 2004.

    "Most of the narrow muddy alleys were gone. They had become wide, neat roads."

    Zhang and his colleagues, who left their footprints in almost every corner of the region, swap stories -- especially odd ones --when they return from mapping expeditions.

    A story that sticks in his mind was told by an older colleague about how local shepherds ate naan, a round flatbread that's a specialty of the Uygur minority, decades ago.

    "They would find a stream, throw a piece of naan into it and let it float along the current. When it came to the lower reaches, the stone-hard bread would be soft enough to be eaten."

    That might be a tall tale, but naan, made of corn flour, was the most important and sometimes only food of local people in those years.

    Zhang himself softened naan with water taken from the small pools that local people built to collect rainwater, when he worked in the field in early years.

    "The water was so muddy that you would not see your fingers if you dipped your hand in it," he said.

    Many locals had Graves' disease, a thyroid disorder, due to poor water and food. These days, most villages have tap water and eat a diversified diet.

    He heard more positive stories, some of which he witnessed himself in recent years.

    At the foot of K2, the second-highest mountain on Earth that lies on the China-Pakistan border, the long barren highland has become a hub of mountaineers worldwide since this area opened to foreigners in the early 1980s. Local Tajiks got rich by running a camel business to carry supplies for mountaineers.

    Deep in the world's second-largest desert, the Taklimakan, farmers are growing a medicinal herb named saline cistanche, which likes hot and dry weather, on large farms.

    "Many shepherds have motorbikes or cars instead of riding horses. On the summer ranges, they use solar batteries to supply power to their tents. It is incredible to see these changes," Zhang said.

    His own life is different, too. "Field work is always tough but comparatively comfortable these days," he said.

    The 120 km of mountain road in the Karakoram Range that took mapping teams a day to drive 30 years ago can be covered in about two hours now.

    "The mountain path used to be very rocky. Rain would wash sand away from the surface, leaving only big rocks. Sitting in a moving vehicle was like sitting on strings," he said.

    The road is much better now, as are the vehicles. In the 1960s,mapping teams rode donkeys, horses and camels. In the 1970s and 80s, trucks played a big role. Now, troops make the trip in all-terrain vehicles with supplies for long stays in high-altitude areas.

    The work is getting safer, too. Since its founding in 1950, Xinjiang's army mapping service has lost 18 staff to field work, but only one in the past three decades.

    This summer, Zhang's department set out to produce 165 maps drawn to a scale of 1:50,000, mostly of the Taklimakan Desert, the Karakoram Range, the Altay Mountains in north Xinjiang and Pamir Mountains along the China-Tajikistan border.

    Nine of his colleagues spent five months in the field for these maps. "You could not imagine this 30 years ago when a whole department with 70 people could only draw about 30 maps a year."

    With satellites and global positioning system technology, the mapping department can position a site easily. In the old days, field workers had to manually locate five to six coordinates for one site.

    Since many remote areas are inaccessible for humans, old maps contained few details. Now, remote-sensing satellites fill in the blanks.

    Computers are widely used in mapping, such as plotting and printing. Young officers can barely imagine plotting a map with pens as in the 1960s.

    "The past three decades, especially the past decade, have been revolutionary for mapping work," Zhang said.