The Northwestern Section of the Wall
|The Great Wall across China's northwestern border areas.|
The Northwestern Section of the Wall
Practically all of the western section of theMing Great Wall stands on western China'sloess plateau. Crossing the sandy edge ofNingxia, it traverses a thousand h intoGansu's Gobi Desert, a vast stretch of sanddrifts and barren land criss--crossed by riftsand gullies. The silvery-grey alkaline terrain, like the barren mountainsides, is devoid of any vegetation, and only sparselydotted with tiny oases.
It was for historical reasons--political,economic as well as strategic--that such aroute was chosen for this section of theGreat Wall.
|A castle and beacon tower on the loess plateau.|
In the past, even as late as the Songdynasty (A.D. 960-1279), the region hadbeen rich pasture land covered with forests.It owed its prosperity to the First Emperor ofQin (Qin Shi Huang) who, after his conquest of the nation in the Znd century B.C.,ordered an enormous stretch of land plantedwith elms to form an impenetrable barrierover hundreds of kilometres that wouldimpede invading cavalry from the north.The green barricade, called Yu Sal (ElmFortification), remained till the sib century.
Likewise, in the 2nd century B.C. thecorridor west of the Yellow River had been athriving grassland with dense patches ofwoods. Even the name of Mount Helan inNingxia was associated with the forest. At the time of the Tang dynasty the mountainwas overgrown with forest that covered theslopes in a luxuriant green. Viewed from adistance it resembled a beautiful horse. Asthe word for "horse" was helan in thelanguage of the nomadic tribes, in time thisbecame the name of the mountain.
|Remains of the earthen Great Wall in Yulin county.|
Besides grassland and forest, northernShaanxi was also a plentiful source of bamboo. This accounts for the description inancient literature of Shaanxi children playing at mock horse races by holding bamboosticks between their legs.
Ningxia, however, had been reduced todesert by the late Ming dynasty. In factvegetation destruction in the corridor westof the Yellow River and in the river's GreatBend had begun before the Christian era.Both the First Emperor of Qin and EmperorWu of Han, who reigned in the Znd and lstcenturies B.C. respectively, sent huge armies here to fight the nomadic Huns andbuild walls. The troops felled trees to cultivate croplands, and used the wood for fueland building material. In subsequent generations the forests here supplied timber forthe palaces of the ancient capital of China, Chang'an (now Xi'an). All this helped todestroy large areas of vegetation, but it wasin the Ming dynasty that the worst devastation was wrought.
|Suppress-the North Platform (Zhen Bei Tai), a four-tier stone structure, stands 7 1/2 kilometres north of the county seat of Yulin in Shaanxi at a strategic point in the northwestern section of the Ming Great Wall.|
The Ming emperors stationed 300,000troops in northern Shaanxi, Ningxia and thecorridor west of the Yellow River. Morethan half of these men were put to workcultivating the land, their task aided by hugenumbers of civilians who migrated from thehinterland provinces. Statistically, by themiddle of the Ming dynasty a total of16,840,000 mu (approximately 1.12 millionhectares) of forest were converted to cropfields. This entailed a ruthless destruction offorests and grassland--a catastrophe for theenvironment.
By the late 1400s close to 860 kilometresof Wall had been built between what is nowFugu county to the county of Dingbian.Many sections of this wall are strengthenedby additional parallel walls called nang baocheng (bag walls). By 1478 a stretch of 3,000kilometres of wall with 14,000 battle towershad been erected from northern Shaanxi toGansu. On the water-short, sterile terrainthe garrison troops had to depend on the fewoases for food crops, but these would havebeen lost if they had withdrawn furthersouth and built the walls on the mountains.Rather, the defence line had to be builtbetween the loess plateau and the GobiDesert so as best to protect all the arableland and water sources.
Building walls on the loess plateau was noless difficult than, say, on the mountains inHebei province. The biggest problem wasthe shortage of water, which was required inenormous quantities for making the mud.The men suffered untold hardships toting orback-hauling water from springs or streamssometimes dozens of kilometres away.
|An earthen wall in Ningxia.|
In Ningxia and Gansu not only was waterscarce--it was difficult even to get earth.Near the foot of Mount Helan and in thecorridor zone west of the Yellow River thegravel cover is dozens of metres thick.Elsewhere the ground is covered with alayer of sand almost as formidable. Theyellow earth had to be dug from alluvialpatches around the mouths of valleys, thenthe stones removed before the preciousearth could be hauled to the constructionsite. This was done at a staggering cost oflabour.
Under these circumstances, attempts weremade to dig ditches as a defence measureinstead of building walls. In 1531 a ditchforty kilometres long was dug near Sanguankou, 45 kilometres northeast of Yinchuancity, at the cost of the hard toil of 10,000men and enormous expense. The ditch verysoon filled up with drifting sand. Frequentdredging failed to solve the problem, andthe ditch idea was finally abandoned.
|The Great Wall here has been buried by the shifting sands of the Maowusu Desert, but it can be identified by the continous ridge of sand dunes.|
For all the difficulties experienced in itsconstruction, this part of the Great Wall isremarkably strong and durable. In Ningxiaand Gansu much of the wall and the manybeacon towers along it, all built with mud,stand in good condition to this day. In someplaces the remains stand seven metres highand six-and-a-half metres wide, and thebeacon towers twelve metres high. At apoint called Guozigoukou at the foot ofMount Helan, a section of stone wall hassurvived earthquakes that caused it to driftmore than a metre both sideways and vertically. It has attracted the interest of Chineseand foreign seismologists, and a seismological observation post has been set up there.
The northwestern section of the GreatWall, however, for all the back-breaking toiland expense it took to build it, failed toprovide the intended security due to a lackof natural barriers on the vast expanse ofopen terrain on which it stood. The garrisonstrength of 300,000 spread along severalthousand li proved vulnerable to the Tartarinvaders, who would concentrate thousandso f horsemen on a single point, cross the wallthrough a gap they had torn, engage inunbridled pillaging, then withdraw withtheir spoils. Many a garrison commanderwas punished mercilessly for incompetencein battle, but this did little to alleviate thepassive position of the defenders. As a lastresort, continued efforts were directed towards consolidating the walls while additional walls and battle towers were builtbetween northern Shaanxi and Gansu.
|The Ming dynasty wall at Sanguankou by Mount Helan.|
With the climate dehumidified, rainfalllessened, the lakes dried ups and sand dunesmoving down 'from the north devoured largeareas of crop land and much of the GreatWall itself.
Over the past three decades experimentshave been made to control the sand. Protective forest belts have been planted and theseare already proving effective. Productiongrowth has been noted in agriculture andanimal husbandry in northern Shaanxi,sheep and Chinese wolf berry in Ningxia,and forestry and agriculture in Gansu.
The government of China has recentlylaunched a major programme for the opening up of barren land in northwesternChina. Aimed at restoring the badly perverted ecological balance in the region, it is agiant task that must be, and will be, accomplished by the efforts of generations.