War­rriors of the sand dunes in North China

Creep­ing deserts pose a se­vere threat world­wide, and in North China every­one is pitch­ing in to stop them in their tracks

China Daily (Hong Kong) - - FRONT PAGE - By YANG YANG yangyangs@chi­nadaily.com.cn

It was the long­est day of the year, and the sun would fi­nally dis­ap­pear be­low the hori­zon only af­ter 9.30 pm. As tour buses slowly rolled into Cres­cent Spring scenic area in Dun­huang, Gansu prov­ince, ex­cited pas­sen­gers held their cam­eras and mo­bile phones aloft, ea­ger to get shots, on both sides of the road, of the sand dunes at the foot of Singing Sands Moun­tain.

To eyes look­ing on from afar in fad­ing light these gi­gan­tic dunes could eas­ily have been di­nosaurs — al­beit ones with silky smooth skin — rest­ing qui­etly on their bel­lies and about to set­tle in for the night.

Although it was still hot out in the open, the sand dunes, stretch­ing this way and that as far as the eye could see, seemed to work a cool­ing, sooth­ing magic, par­tic­u­larly the nearer we got to the small lake in the cres­cent shaped area that gives the place its name, a trav­eler’s oa­sis where, at the end of a long jour­ney, green plants can be seen once again.

Shogo Ma­suda, an of­fi­cial with the Ja­panese em­bassy in Bei­jing and one of 15 diplo­mats in the del­e­ga­tion on the trip, aimed at show­cas­ing the Chi­nese govern­ment’s ef­forts to de­ploy all the forces of foresta­tion to halt the march of the spread­ing desert, called me over, keen to show me some­thing he had just dis­cov­ered af­ter dig­ging a hole in the sand be­side the lake.

“It gets moister the deeper you dig,” he said.

It was true, and the sand felt cooler when my bare foot touched the bot­tom. I looked around and no­ticed that the south bank of the spring looked darker.

“The spring used to be much larger,” I said, re­call­ing what I had read ear­lier about how it has shrunk.

Dun­huang has av­er­age rain­fall of less than 50 mil­lime­ters a year, but in that time about 60 times that evap­o­rates, too. How­ever, for thou- sands of years the nat­u­ral won­der that is Cres­cent Spring has been happy to cock a snook at the arid­ity that sur­rounds it.

Fifty years ago the spring, draw­ing wa­ter from be­low, was about 10 me­ters deep and cov­ered about 15,000 square me­ters. How­ever, since the 1970s the wa­ter level has dropped by as much as 10 me­ters, in line with that of Dun­huang gen­er­ally, mean­ing that the well has at times been vir­tu­ally dry.

In 2004 lo­cals mo­bi­lized to res­cue the well by adding wa­ter to it. The wa­ter level is now sta­ble af­ter hav­ing risen from be­tween 0.1m and 0.5m to about 0.7m to 1m in the past 13 years.

“How­ever, it will be ex­tremely hard to get it back to its orig­i­nal nat­u­ral state,” says Zhang Mingquan, a pro­fes­sor of en­vi­ron­men­tal sciences at Lanzhou Uni­ver­sity.

An­other threat to the spring is the sur­round­ing sand. With­out proper de­ser­ti­fi­ca­tion con­trol, the spring would prob­a­bly be buried, says Qu Jian­jun, re­searcher at the Cold and Arid Re­gions En­vi­ron­men­tal and En­gi­neer­ing Re­search In­sti­tute, part of the Chi­nese Academy of Sciences. The main mea­sure is to fell tall poplar trees and de­mol­ish build­ings to cre­ate a wind tun­nel for north­east­erly winds, he says.

Dun­huang was the last stop on a five-day jour­ney that started in the pro­vin­cial cap­i­tal, Lanzhou, 1,100 kilo­me­ters to the south­east, where the achieve­ments of the Three­North For­est Shel­ter Belt De­vel­op­ment Pro­gram and the great com­bat against de­ser­ti­fi­ca­tion in China for nearly 40 years are on dis­play.

In Novem­ber 1978, China started plan­ning huge shel­ter belts in the coun­try’s north to mit­i­gate drought, sand­storms and soil ero­sion. The pro­gram cov­ers 42 per­cent of China’s land area.

It is not as though China is alone in its fight. World­wide, creep­ing deserts pose a threat, and ac­cord­ing to the United Na­tions, 6.6 per­cent of the land on Earth is cov­ered with deserts, and 34.6 per­cent is dry­lands. 2.1 bil­lion peo­ple world­wide live in deserts and dry­lands. 110 coun­tries are fac­ing the prob­lem of land de­grad­ing.

Ev­ery year, 12 mil­lion hectares of land are lost, an area the size of Benin.

In China, although the com­bat against de­ser­ti­fi­ca­tion is help­ing grad­u­ally re­duce the area cov­ered by sand, there was still 2.6 mil­lion square kilo­me­ters of such land at the end of 2014, about 27 per­cent of the whole ter­ri­tory.

There was also 1.7 mil­lion sq km of san­di­fied land, about 18 per­cent of the na­tional ter­ri­tory, the State Forestry Ad­min­is­tra­tion says.

More than 43 per­cent of Gansu’s sur­face area, 195,000 sq km, is desert, and more than 27 per­cent, that is, 120,000 sq km, is san­di­fied. This frag­ile en­vi­ron­ment greatly hob­bles the prov­ince’s eco­nomic growth.

Nev­er­the­less, ef­forts to rein in de­ser­ti­fi­ca­tion have borne fruit over the past eight years, the prov­ince’s desert land shrink­ing by 1,914 sq km and its san­di­fied land by 742 sq km. More than 1,000 com­pa­nies

“Ten years ago all this fine sand would blow in the wind. Now, in cre­at­ing this man-made semi-desert, we have brought in peb­bles from 15 kilo­me­ters away, and with the one-kilo­me­ter long plant bar­rier, mov­ing sand won’t ac­cu­mu­late here.” Zhang Guobin of the Dun­huang Academy

en­gaged in this fight have been set up in the prov­ince over that time, and they are reck­oned to have an­nual turnover of 15.3 bil­lion yuan ($2.26 bil­lion).

Of course, Cres­cent Spring is just one to­ken of the bat­tle against creep­ing deserts.

Start­ing from Lanzhou, the del­e­ga­tion trav­elled along the 1,000-km Hexi Cor­ri­dor, the artery that con­nects China with Tarim Basin and Cen­tral Asia and served as a con­duit for Bud­dhism, trade and mil­i­tary ven­tures in an­cient times. In the cor­ri­dor, west of the Yel­low River, as the name Hexi in­di­cates, four oases are strung along from east to west among deserts and semi-desert: Wuwei, Zhangye, Ji­uquan and Dun­huang.

The land­scape on both sides of the high­way be­tween Qil­ian Moun­tain in the west and Heli Moun­tain in the east changes con­tin­u­ously from semidesert on which tough, short shrubs grow, then land with more shrubs and green land on which taller trees grow. The change is par­tic­u­larly no­tice­able if you take the high-speed train that tra­verses the vast bar­ren semi-desert of Ji­uquan, passes by Ji­ayuguan, where the western end of the Great Wall built dur­ing the Ming Dy­nasty (1368-1644) is lo­cated, and takes you to Li­uyuan South Sta­tion, north­east of Dun­huang.

In the 90-minute drive from the train sta­tion to down­town Dun­huang it is easy to see the changes of land­scape from semi-desert, the wet­ter land where clus­ters of rose wil­low grow, and where trees and crops grow, and the green ex­panses on the out­skirts of the city, where the kinds of land­scape seen ear­lier are scarcely imag­in­able.

Her­itage site

Mo­gao Grot­toes, the World Cul­tural Her­itage site a 50-minute drive from Cres­cent Spring, is on the south­east­ern edge of the Kum­tagh Desert, one of the largest deserts in China, and at the foot of Singing Sands Moun­tain. The weather is dry, and fly­ing sand, car­ried along by fierce winds, is a fre­quent, if not con­stant, com­pan­ion. In pre­serv­ing the 1,600-year-old grot­toes, dry­ness has been an ally, but the wind and sand dam­age the caves and mu­rals. In fact there in the 1940s the en­trance of the caves was buried in sand.

At the en­trance of cave No 17 of Mo­gao Grot­toes, guides in­vite vis­i­tors to in­spect the scars that sand has left on walls, sand that buried the en­trance of the cave com­pletely, too, be­fore the Taoist priest Wang Yuanlu dis­cov­ered thou­sands of rolls of Bud­dhist su­tra in the cave in 1900.

“Car­ried along by the wind are minute sand par­ti­cles in­vis­i­ble to the naked eye, and these things have sharp cor­ners and edges that cut into the sur­face of mu­rals, de­grad­ing the color,” says Zhang Guobin of the Dun­huang Academy, who is in charge of sand con­trol.

On the top of the Mo­gao Grot­toes, wind blows mainly from three direc­tions, north­east, north­west and most fre­quently south. These winds carry with them sand from Singing Sands Moun­tain and the nearby Gobi.

Af­ter study­ing the wind con­di­tions and the flow of the mov­ing sand, re­searchers have taken steps to com­bat the ero­sion of wind and sand.

They have built A-shaped sand bar­ri­ers so sand that north­west­lerly winds car­ries along is blown back by winds from the north­east. This re­duces sand moved by north­west­erly winds by 95 per­cent, and sand ac­cu­mu­lated at night by 60 per cent.

They have also cre­ated a man­made semi-desert, press­ing stones of cer­tain sizes into the sand to pre­vent sand from fly­ing.

“Ten years ago all this fine sand would blow in the wind,” Zhang says. “Now, in cre­at­ing this man­made semi-desert, we have brought in peb­bles from 15 kilo­me­ters away, and with the one-kilo­me­ter long plant bar­rier, mov­ing sand won’t ac­cu­mu­late here.”

In ad­di­tion, wo­ven straw or ny­lon nets have been buried in the sand to form check­box bar­ri­ers against the wind.

Once sand is en­sconced in these bar­ri­ers, wind-break­ing seedlings such as Cal­ligonum, cara­gana and sac­saoul, which are re­sis­tant to drought and cold, are planted in the cen­ter of the boxes.

In the past 10 years, Li Rui, 40, one of the four work­ers re­spon­si­ble for sand con­trol with Dun­huang Academy, says he has seen more than 1.15 mil­lion-square-me­ters of check­box bar­ri­ers be­ing built. He and oth­ers con­stantly mon­i­tor the top of the sand moun­tain, en­sur­ing that the check­boxes and plants are do­ing their job. At the foot of these boxes and plants, run black rub­ber pipes that trans­port wa­ter to the top of the sand moun­tain, drip­ping it into the sand to pro­mote growth.

Some­times the work­ers help re­search in­sti­tutes with ex­per­i­ments such as build­ing a wind tun­nel to de­ter­mine the ideal den­sity of grit, and the size of its par­ti­cles, that is spread on the sur­face of sand to stop it blow­ing in the wind.

“That is how we built the semidesert there,” Li says, point­ing to a darker flat area along the road, where peb­bles are scat­tered over more than 1.67 mil­lion sq m of sand.

PHO­TOS BY YANG YANG / CHINA DAILY

Top: Cara­gana is planted on the loess plateau in Yuzhong county, Lanzhou, Gansu prov­ince to pre­serve rain­wa­ter and soil. Above: Cai Chengcheng, deputy head of Min­qin county, ex­plains the char­ac­ter­is­tics of sac­saoul, a plant that can keep sand in place.

PHO­TOS BY YANG YANG / CHINA DAILY AND PRO­VIDED TO CHINA DAILY

Gongjing Tree Farm in Yuzhong county;diplo­mats visit a de­ser­ti­fi­ca­tion con­trol pi­lot spot; an old tree at Cres­cent Spring scenic area; an ex­hi­bi­tion of de­ser­ti­fi­ca­tion con­trol on Gongjing Tree Farm; a sand dune de­ployed with sac­saoul fix near the Mo­gao Grot­toes.

Clock­wise from top:

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