Shaanxi contains both halves of China, and the border is a mountain range
The Qinling range separates the Yellow River basin from the Yangtze's, the temperate north from the subtropical south, and wheat from rice. Shaanxi contains the whole of it, and with it both halves of the country.
Most countries have no clear internal border. You move from one region to another by gradation, and the limit is an administrative convention. China has a notable exception, and it is a specific mountain range with a name of its own.
It is called Qinling, it runs from east to west and it separates the country's north from its south. What is interesting for a traveller is that one province contains the whole of it, and therefore contains both Chinas: Shaanxi, 205,800 square kilometres and some 39.5 million inhabitants, with the range running through the middle.
01 A range that works as a border
The Qinling works as a border in several senses at once, and that is why it works. The first is hydrographic: it is the watershed between China's two great rivers, the Yellow to the north and the Yangtze to the south. What falls on one flank ends up in one river and what falls on the other, in the other.
The second is climatic. The range is the divide between the warm temperate zone and the northern subtropical one. In winter it blocks the waves of cold air coming down from the north and stops them entering the south; in summer it does the opposite, and blocks the sea moisture rising from the south-east.
Its highest point is Mount Taibai, at 3,771 metres, and that height explains the barrier's effectiveness. One qualification is in order, because scholars themselves make it: the transition between climate zones is gradual and there is no exact line. What there is, is a narrow band where everything changes.
02 To the north, a hundred metres of dust
The province's north, called Shaanbei and made up of Yulin and Yan'an, belongs to the Loess Plateau. Loess is silt carried by the wind, and here it is not a layer: it is the entire terrain. The deposits reach between 200 and 300 metres thick near the Liupan mountains and some 100 metres beside the Yellow River.
The material came from the Gobi and the neighbouring deserts, and deposition began 2.4 million years ago. The full plateau covers 635,000 square kilometres, 6.6 % of China's surface, and supports some 108 million people.
Loess has a property that decides the landscape: it erodes with extraordinary ease. More than 90 % of the sediment carried by the Yellow River comes from this plateau, and that is where the river gets its name. The result is a relief of hills cut by deep gullies.
03 To the south, the Yangtze basin
Cross the range and you are in another country. The province's south, the Shaannan, is made up of Hanzhong, Ankang and Shangluo, is mountainous and drains into the Yangtze. The climate is humid, the vegetation is dense and the basic crop changes.
This contrast is what makes Shaanxi special as a destination. You do not need to cross the country to see the two Chinas: the dry, yellow plateau of the north-west and the green, humid mountains of the south fit in the same province, and between them lie a few hours by road.
The wildlife changes too. The Qinling flank is the habitat of a giant panda population distinct from Sichuan's, and the range's forest is recognised as one of the country's areas of greatest biological value.
04 And in the middle, the valley where the people live
Between the plateau and the range lies the third piece, and it is the one that explains the history: the Guanzhong, the basin of the Wei river. It is a fertile plain formed of sediment, wedged between the loess to the north and the Qinling to the south, and most of the province's population lives there.
In that valley stands Xi'an, the capital, and its position is no accident. A cultivable flat, protected by mountains to the south and plateau to the north, with a river running through it, is exactly what an ancient capital needs. Thirteen dynasties chose it over more than 1,100 years, under the names Fenghao and Chang'an.
Everything you visit in the province comes out of that logic. The Terracotta Army sits on the valley's edge, at the foot of Mount Li; the imperial tumuli line up across the plain; the wall encloses the city centre. A capital of eleven hundred years leaves a lot buried.
05 The border can also be eaten
The range's most everyday consequence is on the table. The Qinling line, extended eastwards by the Huai river, is also the agricultural border between the wheat of northern China and the rice of the south.
North of that line, in the Guanzhong, the grain is wheat, and it has been cultivated there since the time of the Zhou dynasty. From that comes all of Xi'an's recognisable cooking: noodles, flatbreads, doughs. South of the Qinling, in Hanzhong and Ankang, rice and chilli appear.
It is probably the best indicator that the border really exists. A climatic limit you can verify by looking at what is served at a food stall is not an atlas convention.
06 How to read the province
The first practical consequence is that it pays to organise the trip in three stretches rather than one. Xi'an and the Wei valley for the archaeology; the north, Yan'an and Yulin, for the loess landscape; the south, Hanzhong and the Qinling, for the humid mountains. Three different destinations under one licence plate.
The second is that altitude and latitude do not go together here. Crossing the Qinling from north to south means climbing to a pass and dropping into another climate, not going south in the usual sense. A single day's travel can start in a semi-arid landscape and end in a forest.
And the third is the one that reorders the whole trip. If you accept that you are travelling along the country's seam rather than through just another province, everything fits: loess to the north, rice to the south, wheat in the middle and a capital of thirteen dynasties placed exactly on the only available plain.
