Geography Reference
In-Depth Information
Remains of city walls are still discernible and sites of blacksmiths' workshops in the
city may be identified by fragments of scrap iron, bronze arrowheads and heaps of
debris scattered all over the place. Some local shepherds we met told us that there
was a huge pit filled with skeletons outside the city, marking the site of an ancient
battlefield. Ruins of two other Han cities have been discovered. The first lies some
20 km to the south and the other some 30 km to the south-east of Yuhun. The former
was called Sanfeng and the latter Linrong. The space between these two and Yuhun
is dotted with groups of Han graves as well as ruins of hamlets and fields, discern-
ible even to this day. As a result of peaceful co-existence between the Han Dynasty
and the Huns, the last 50 years B.C. enjoyed an unprecedented spell of quiet and
stability. During this period reclamation extended from the neighbourhoods of the
three cities to the southern edge of the Yin Mountains. Historical records indicate
that population increased, cows and horses flocked in the fields and that cities which
had been securely guarded in the past now shut their gates at a very late hour. It
really became a scene of prosperity and abundance.
What does it look like now? The Mongolian term “Ulanbuhe” aptly describes the
present state of this area, a region devastated by moving sand. The process started long
before modern times. In 981 A.D. a traveller named Wang Yan-de crossed the Yellow
River at the Ordos Plateau, passed through here and journeyed westward to the Ju-yan
area. He took detailed notes of living conditions in this district, recording: “No food
crops ever grew here, except a kind of grass called Denshiang, the seeds of which are
gathered for food”. According to our investigation, Denshiang is what we now call
shami
(sand seeds or
Agriophyllum arenarium
), a kind of pioneering plant growing on sand
dunes, the first that ever grew on them. The fact that sand seeds could be gathered for
food shows that they grew in abundance and yielded large quantities of seeds. It may be
inferred that a 1,000 years ago, this area was still in the early stages of blown sand
encroachment and has been entirely desertified in the course of the present millennium.
Near the city of Yuhun, we saw wind-eroded pits of varying sizes, huge pits
formed by intense wind erosion. In a natural section at the edge of a wind-eroded
pit, we could identify clearly that a horizontally-deposited layer of clay, 70 mm
thick, had under it nothing but fine sand. It is easy to see that when the surface layer
was broken, the fine sand underneath was liable to be blown away by fierce north-
west winds. This is the chief source of blown sand in this area. The thickness of the
surface layer of clay we saw here varied from place to place, thicker in some places,
thinner in others. It was not very difficult to reclaim land where the clay was thick,
but where it was thin, if the primeval vegetation was removed and the surface
exposed to wind erosion, the place was likely to turn into a sandy tract of its own
accord. This is exactly what history has taught us.
8.3
The Settlement and Abandonment of Tongwan
Finally, please allow me to touch upon another ancient city in the desert. It is the
biggest among the relict sites of ancient cities in the desert of western Inner
Mongolia and the most remarkable in architectural engineering I have seen so far.
