|DIGGING CAVES TO CATCH WATER
Definition characters description and diffusion
During the Neolithic Age in the south of Italy, the climate ranged from freezing winters to scorching summers. Water shortage fostered practices for meteoric water collection and underground storage. Caves keep a constant temperature throughout the year and are the ideal shelters for human beings and animals, for the storage of grain and mainly of water. The latter is the most precious underground resource: water dripping from walls, seeping out from the rocks, forming puddles, and, though always drawn 'miraculously' keeping at a steady level, just as in the cave of Manduria described by Pliny (Natural History, II, 226).
General characters description and diffusion
Each underground cavity can be related to water harvesting techniques or to water related rites. Evidence of such practices, dating back to the 4th millennium (Tinè and Isetti, 1980), were found in the Grotta Scaloria, along the Gargano slopes, in Apulia, in the form of ceramic pots, which were placed under stalactites to harvest dripping water. With the passage of time, the slope below was used for dwellings and agro-pastoral activities thanks to the excavation of caves provided with bell-shaped cisterns which extended downwards to the network of water and of gaden threshing-floors. These techniques spread over the arid karstic areas and the limestone highlands as well as the semiarid clay and loess plains. In the latter the ease of excavation allows very large settlements with housing patterns that have been perpetuated up to our time such as in China in the Loess zone. The underground house provides heat benefits and saves land on the surface. That is why it persists in the Loire Valley in France, where the highly valuable vineyards for the production of vintage wines explains the digging out of caves, cellars, and underground houses. In Ethiopia, underground dwellings and churches are used by the Agau people at Ucrò, whose name derives from the root waqara, standing for 'to dig' as well as at Dongollo, which means 'stone'. These are very characteristic structures since they were built by digging wide-open pits with a big block of stone left in the middle. This was then hollowed out and worked on the outside to build a church, which is therefore a monolith, having the roof at the level of the plain, from which the deep ditch seperates it. The most massive structures of this type are in the site of Lailbela. They were made by using both techniques of open-air excavation of pit-courtyards, peculiar to North Africa and southern Italy, and of hollowing underground rooms out, as in Egypt, in Petra, in the Sassi of Matera and in Cappadocia. Churches are provided with impluviums and systems supplying water to baptismal fonts. A network of open-air ditches, tunnels, and channels surrounds these monumental structures. The practice has been mostly abandoned and replaced by meteoric water catchment methods. It is still used when considerable quantities of spring water are caught inside a cave. In that case, water catchment inside the cave often evolves in the drainage tunnel technique. The existing examples have more a monumental and historical value than potential water supply.
Advantages and sustainability
Caves provided shelter for humans as well as storage space for grains and a means of collecting and storing water, all processes vital to human survival.