There are a lot of problems that need addressing, but I think that'd be the marker of the Tocharian civilisation, how they adapt the mountains and the desert rim to facilitate their Empire. The only Empire I can think of for the PoD to mimic really is the Inca.
Excellent post! I would add the civilization of Iran, with its extensive system of underground
qanats:
A
qanāt (
Arabic: قناة) or
kārīz (
Persian: کاریز) is a gently sloping underground channel to transport water from an
aquifer or
water well to surface for
irrigation and drinking. This is an old system of
water supply from a deep well with a series of vertical access shafts. The qanats still create a reliable supply of water for human settlements and irrigation in hot,
arid, and
semi-arid climates, but the value of this system is directly related to the quality, volume, and regularity of the water flow. Traditionally qanats are built by a group of skilled laborers, muqannīs, with hand labor. The profession historically paid well and was typically handed down from father to son. According to most sources, the qanat technology was developed in
ancient Iran by the
Persian people sometime in the early 1st millennium BC, and spread from there slowly westward and eastward. However, some other sources suggest a Southeast Arabian origin.
[...]
Qanats are constructed as a series of
well-like vertical
shafts, connected by gently
sloping tunnels. Qanats efficiently deliver large amounts of subterranean water to the surface without need for pumping. The water drains by
gravity, typically from an upland
aquifer, with the destination lower than the source. Qanats allow water to be transported over long distances in hot dry climates without much water loss to
evaporation.
[...]
Qanats are sometimes split into an underground distribution network of smaller canals called
kariz. Like qanats, these smaller canals are below ground to avoid contamination and evaporation. In some cases water from a qanat is stored in a reservoir, typically with night flow stored for daytime use. An
ab anbar is an example of a traditional Persian qanat-fed reservoir for drinking water.
The qanat system has the advantage of being resistant to natural disasters such as earthquakes and floods, and to deliberate destruction in war. Furthermore, it is almost insensitive to the levels of precipitation, delivering a flow with only gradual variations from wet to dry years. From a sustainability perspective, qanats are powered only by gravity, and thus have low operation & maintenance costs once built. Qanats transfer freshwater from the mountain plateau to the lower-lying plains with saltier soil. This helps to control
soil salinity and prevent desertification.
[...]
The value of the qanat is directly related to the quality, volume, and regularity of the water flow. Much of the population of
Iran and other arid countries in Asia and North Africa historically depended upon the water from qanats; the areas of population corresponded closely to the areas where qanats are possible. Although a qanat was expensive to construct, its long-term value to the community, and thereby to the group that invested in building and maintaining it, was substantial.
[...]
A typical town or city in Iran, and elsewhere where the qanat is used, has more than one qanat. Fields and gardens are located both over the qanats a short distance before they emerge from the ground and below the surface outlet. Water from the qanats defines both the social regions in the city and the layout of the city.
The water is freshest, cleanest, and coolest in the upper reaches and more prosperous people live at the outlet or immediately upstream of the outlet. When the qanat is still below ground, the water is drawn to the surface via
water wells or animal driven
Persian wells. Private subterranean reservoirs could supply houses and buildings for domestic use and garden irrigation as well. Further, air flow from the qanat is used to cool an underground summer room (
shabestan) found in many older houses and buildings.
Downstream of the outlet, the water runs through surface canals called jubs (
jūbs) which run downhill, with lateral branches to carry water to the neighborhood, gardens and fields. The streets normally parallel the jubs and their lateral branches. As a result, the cities and towns are oriented consistent with the gradient of the land; this is a practical response to efficient water distribution over varying terrain.
