Are we having fun yet?
For the first couple hundred kilometres of our trip, the walking was easy. We had more than our share of hot days, and we were forced to carry a lot of weight in water; but apart from a few bumps around Xiakou, the terrain was remarkably gentle. (Okay, it was rough enough for Brendan to injure his foot, but then Brendan once managed to break a rib playing pool.)
Anyway, for the entire month of June, walking over a distance of nearly 400 kilometres, our total elevation gain was 1837 metres. For a mountain climber, that’s not even a big day.
But easy street ended rather abruptly. Just east of Wuwei, where we set off in search of the mythical blonde-haired Chinese, the Qilian Shan mountain range tails off to the south and the runoff that feeds Hexi Corridor agriculture dribbles away with it. As we walked out of the town of Tumen, the wall ascended some small sandy rises. Within the space of a few kilometres, endless horizons were replaced with waves of hills and valleys, and where we once crossed shallow desert washes and lazy irrigation overflows, we were now negotiating canyons with sheer walls hundred of metres deep.
The wall rising to the foothills
The wall disappearing into a canyon east of Tumen
This canyon was too steep to cross; we had to walk to the head of it and around
The reason for all these ups and downs is loess, a fine-grained, fertile – and importantly for us – highly erodible soil. Loess covers over 400,000 square kilometres of north-central China, a region known as the Loess Plateau; and the soil goes a long way down: 50-80 metres deep on average, 150 metres deep in places. This soil is so soft you can dig a decent hole with your bare hands, so you can just imagine what a bit of water, a steep gradient and thousands of years can do.
Brendan approaching yet another canyon
Loess tan! It’s safe, effective and washes away with water!
Loess has played an important role in Chinese history; it’s really no exaggeration to say it’s the dirt that gave birth to China. Loess is not only fertile, it is also easily worked with simple tools. As a result, some of China’s oldest agricultural settlements were founded on the most easily irrigated portions of the Loess Plateau. Many of China’s oldest buildings were made of rammed loess; so is much of the wall.
Loess continues to be an important building material to this day. Most of the buildings in the small villages we’ve passed through are constructed from adobe brick. In the area east of Tumen, the loess is deep enough to construct large, comfortable caves suitable for permanent habitation. In these foothills there are entire villages of cave dwellings.
A cave village
All of that fertile soil isn’t much good unless there’s water, though, and there is precious little of it in the foothills where we walked. In the flatter bottomlands, we saw small fields of dryland wheat; in the uplands, however, the fields have mostly been abandoned – whether that is due to drier conditions or other environmental constraints, or simply because marginal agriculture no longer makes sense when there are opportunities in towns such as Tumen a mere 20 kilometres away, we don’t know. Regardless of the reason, the foothills have been left to shepherds, and these days the villages of caves are largely, though not completely, uninhabited.
One of the few caves still in use