for the well, suggesting awareness by the people of the Hemudu culture that their water source required protection (Zhou et al. 2011).
According to archaeological research, the Chinese are credited with developing the percussion method of well construction, a technique that has been in continuous use now for 4000 years. The ‘rope and drop’ method involved a steel rod or piston that was raised and dropped vertically via a rope supported by a bamboo framework. Using this percussion system with a heavy chiselling or crushing tool, wells were drilled to depths of 130 m around 3000 years ago, although construction took years to complete (Zhou et al. 2011). The cable tool drilling rig used today (see Section 7.2.2) is directly descended from the bamboo framework percussion drilling techniques developed in China.
Evidence for the appearance of dams, wells and terraced walls, three methods of water management, is widespread by the Early Bronze Age from 3600 BC, as part of what has been termed a ‘Water Revolution’ (Mithen 2012). The recognisable development of groundwater as part of a water management system also dates from ancient times, as manifest by the wells and horizontal tunnels known as qanats (ghanats) or aflaj (singular, falaj), both Arabic terms describing a small, artificial channel excavated as part of a water distribution system, which appear to have originated in Persia about 3000 years ago. Examples of such systems are found in a band across the arid regions extending from Afghanistan to Morocco. In Oman, the rural villages and aflaj‐supplied oases lie at the heart of Omani culture and tradition. The system of participatory management of communal aflaj is an ancient tradition in Oman by which common‐property flows are channelled and distributed to irrigation plots on a time‐based system, under the management of a local community (Young 2002).
Figure 1.3 shows a cross‐section along a qanat with its typical horizontal or gently sloping gallery laboriously dug through alluvial material, occasionally up to 30 km in length, and with vertical shafts dug at closely spaced intervals to provide access to the tunnel. Groundwater recharging the alluvium in the mountain foothills is fed by gravity flow from beneath the water table at the upper end of the qanat to a ground surface outlet and irrigation canal on the arid plain at its lower end (Fig. 1.4). The depth of the mother well (Fig. 1.3) is normally less than 50 m. Discharges, which vary seasonally with water table fluctuations, seldom exceeding 3 m3 s−1.
Such early exploitation of groundwater as part of a sophisticated engineered system is also evident in the supply of water that fed the fountains of Rome (see Box 1.1). Less sophisticated but none the less significant, hand‐operated pumps installed in wells and boreholes have been used for centuries to obtain water supplies from groundwater found in surface geological deposits. The fundamental design of hand pumps of a plunger (or piston) in a barrel (or cylinder) is recorded in evidence from Greece in about 250 BC (Williams 2009). It is assumed that wooden pumps were in continuous use after the end of the Roman period, although examples are difficult to find given that wooden components perish in time. In Britain, the majority of existing hand‐operated pumps are cast iron, dating from the latter part of the nineteenth century (see Plate 1.1). Although entirely redundant now due to issues of unreliability in dry weather and the risk of surface‐derived pollution, private and domestic pumps were once widely used for supplying houses, farms, inns, almshouses, hospitals, schools and other institutions in cities, towns and villages. Ultimately, as mains water was introduced across Britain from the nineteenth century onwards following the Public Health (Water) Act of 1878, the village pump was superseded by the communal outdoor tap or water pillar, itself made redundant when piped water was provided to individual houses.
Fig. 1.3 Longitudinal section of a qanat (Beaumont 1968 and Biswas 1972).
(Sources: Based on Beaumont, P. (1968) Qanats on the Varamin plain, Iran. Transactions of the Institute of British Geographers 45, 169–179; Biswas, A.K. (1972) History of Hydrology. North‐Holland, Amsterdam.)
Fig. 1.4 Irrigation canal supplied with water by a qanat or falaj in Oman.
(Photograph provided courtesy of M.R. Leeder.)
Box 1.1 The aqueducts of Rome
The aqueducts of ancient Rome are often associated with Roman expertise in civil engineering, and the fact that most of the aqueducts are supplied by springs is a tribute to the importance of groundwater in sustaining human civilization (Deming 2020). The remarkable organization and engineering skills of the Roman civilization are demonstrated in the book written by Sextus Julius Frontinus and translated into English by Bennett (1969). In the year 97 AD, Frontinus was appointed to the post of water commissioner, during the tenure of which he wrote the De Aquis. The work is of a technical nature, written partly for his own instruction, and partly for the benefit of others. In it, Frontinus painstakingly details every aspect of the construction and maintenance of the aqueducts existing in his day.
For more than 400 years, the city of Rome was supplied with water drawn from the River Tiber, and from wells and springs. Springs were held in high esteem, and treated with veneration. Many were believed to have healing properties, such as the springs of Juturna, part of a fountain known from the south side of the Roman Forum. As shown in Fig. 1.5 and illustrated in Plate 1.2, by the time of Frontinus, these supplies were augmented by several aqueducts, presumably giving a reliable supply of good quality water, in many cases dependent on groundwater. For example, the Vergine aqueduct brought water from the estate of Lucullus where soldiers, out hunting for water, were shown springs which, when dug out, yielded a copious supply. Frontinus records that the intake of Vergine is located in a marshy spot, surrounded by a concrete enclosure for the purpose of confining the gushing waters. The length of the water course was 14 105 paces (20.9 km). For 19.1 km of this distance the water was carried in an underground channel, and for 1.8 km above ground, of which 0.8 km was on substructures at various points, and 1.0 km on arches. The source of the Vergine spring, located approximately 13 km east of Rome in the small town of Salone, is shown on a modern hydrogeological map (Boni et al. 1986) as issuing from permeable volcanic rocks with a mean discharge of 1.0 m3 s−1 (Fig. 1.5). Frontinus also describes the Marcia aqueduct with its intake issuing from a tranquil pool of deep green hue. The length of the water‐carrying conduit is 61 710½ paces (91.5 km), with 10.3 km on arches. Today, the source of the Marcia spring is known to issue from extensively fractured limestone rocks with a copious mean discharge of 5.4 m3 s−1.
Fig. 1.5 Map of the general geology in the vicinity of Rome showing the location of the spring sources and routes of Roman aqueducts (Bennett 1969 and Boni et al. 1986).
(Sources: Based on Bennett, C.E. (1969) Frontinus: The Stratagems and the Aqueducts of Rome.
