Vanished Glory!

 The Art & Science of Water.

Written by Richard Covington.

https://archive.aramcoworld.com/issue/200603/the.art.and.science.of.water.htm

The ingenious grid of gutters, pipes, and miniature aqueducts once used to capture precious rainfall and channel it to giant cisterns (aljibes in Spanish; jubb in Arabic) beneath the patio below. From the Middle Ages until the 1950’s, the patio was a cemetery, the derelict cisterns were filled with bones, and the runoff fed the fountains, he says. Now the patio’s well-ordered grove of cinnamon, orange, olive, palm and cypress trees has been restored to the glory it originally enjoyed under the Umayyad rulers, and the cisterns once again collect water for use in the Mezquita. Up on the roof, on this blast furnace of a day, it is perfect weather for appreciating the historic Arab skill of trapping, storing and managing that evanescent, life-giving commodity, water.

The Albolafia Noria, or Waterwheel, is the last vestige of an array of mills and dams built on the Guadalquivir River in Córdoba between the eighth and 10th centuries. It appears on this carved-stone seal of the city, top, and in its present condition, above.

The ruined Albolafia noria, among the last vestiges of the masterful panoply of mills, dams, flood protection and canals that the Umayyads built between the eighth and 10th centuries. (The name of the river comes from the Arabic al-wadi al-Kabir, “great river.”) Barely visible in the shallows are also the remnants of an imposing dam, a nearly three-meter-thick (10') barrier built of stone imported from North Africa and marble columns that once rose three meters above the waterline. In the Islamic era, when the mills were in operation, trip-hammers attached to the axles of water-wheels pounded out paper pulp, husked rice and crushed sugarcane in a process imported from China.

An aqueduct, now long gone, erected on Roman foundations by ninth-century Caliph Abd al-Rahman ii to bring spring water from the Sierra Morena range, 80 kilometers (50 mi) west. By the 10th century, at a time when no city in western Christendom was larger than 10,000 souls, Córdoba boasted a cosmopolitan population of half a million, sustained by one of the most advanced water systems in the world.

Seven kilometers (4.4 mi) west of the city, among the sprawling ruins of Madinat al-Zahara, the garden capital built by Abd al-Rahman III, archeologists have uncovered evidence of a staggering 300 baths—many lavishly painted—as well as artificial fishponds, sculpted marble pools and basins fed by a network of aqueducts and subterranean canals.

From the ninth through the 16th centuries, Islamic societies from Spain to Oman experienced a “golden age” of science and technology. One of the most important of these technologies is also today one of the least thoroughly studied: hydrology, or the control of the movement of water. The rise of cities like Córdoba, Damascus, Baghdad, Fez and Marrakech all required increasingly sophisticated methods of water management to supply rapidly growing populations. Integrating, adapting and refining irrigation techniques and water distribution methods from India, Asia and Rome, Muslim water engineers, starting as early as the seventh century in Arab countries and around the 10th century in Spain, built an agricultural revolution. Unified by a common language, these Arabic-speaking scientific pioneers sowed their expertise from East to West, and their inventive solutions to the challenges of widely varied terrain underpinned the unprecedented prosperity of the era, says Mohammad El Faïz, an economics historian at Cadi Ayyad University in Marrakech.

Gravity-fed fountains embellish a courtyard at the heart of the Alhambra’s sprawling, elaborate Generalife Gardens in Granada.

One of the earliest Arabic texts explaining how to locate aquifers, dig survey wells, and build underground canals, Anabat al-Miya al-Khofia (The Extraction of Hidden Waters to the Surface) was written in Baghdad in the 10th century by the Persian mathematician Muhammad al-Karaji. Meanwhile, physician-philosopher Ibn Sina (Avicenna), who lived primarily in Isfahan and Hamadan between 980 and 1037, established hydraulics as an independent discipline on a par with geometry and astronomy.

The methodology, machines and discoveries surrounding water had far-reaching impacts not only on agriculture, but also on science, law, and social organization—both across the Arab empire and beyond, across the Atlantic. According to Ahmad Hassan of Aleppo University and the late British scholar Donald Hill in their classic 1986 analysis, Islamic Technology, “Muslim irrigation systems with their associated hydraulic works and water-raising machines remained the basis for Spanish agriculture and were transferred to the New World.” After the 15th century, Arab-inspired techniques were adopted in the Canary Islands and as far away as Texas and Louisiana, partly to irrigate thirsty sugarcane fields, explains Antonio Malpica, a professor of medieval history at the University of Granada and an expert on Islamic technology in Spain. In France, he adds, Provençal engineers in the 11th to 13th centuries copied Islamic irrigation networks, and some of them are still in use today.

This quantum leap of experimentation shook the Islamic world. In Diyarbakir in upper Mesopotamia (now in present-day Turkey), the 13th-century engineer al-Jazari designed astonishing hydraulic pumps and ingenious water clocks based on principles so advanced they would not be seen in the West for another 300 years, when Leonardo da Vinci and other Italian inventors copied them. Hassan and Hill note that some are regarded as precursors of the first steam and internal-combustion engines.

In Iran, North Africa and Spain, subterranean canals equipped with a series of ventilating shafts leading to the surface were built to extend 20 kilometers (12 mi) or more. Like more basic devices, they had existed for centuries before Islamic civilization adopted and refined them: According to historian Charles Singer, they were carried from Armenia to Persia around the sixth-century bc, and from there spread west to Egypt and across North Africa to Morocco. Malpica observed that the Arabs preferred to irrigate by canals from underground springs because—unlike rivers, which often dried up in the summer—the water was available year-round.

Islamic engineers used astrolabes, spherical and plane trigonometry, and complex surveying techniques to lay out the canals and to site dams, many of which were built so solidly they have endured into modern times. In Saudi Arabia, for example, about one-third of the dams constructed in the seventh and eighth centuries are still intact, according to Dutch historian Nicholas Schnitter. In the Spanish province of Valencia, eight 10th-century Muslim dams spanning the Turia River still supply much of the region’s irrigation needs. Elsewhere in the former al-Andalus (the Arab name for the southern Iberian peninsula), Syrian immigrants dammed rivers from the Ebro in the north, near Zaragoza, to Córdoba’s Guadalquivir in their attempts to replicate the perfumed gardens of the Ghuta oasis of Damascus.

Water projects frequently attained proportions not seen since such great Roman works as the 100-kilometer (62-mi) aqueduct from the Eifel Mountains to Cologne. In the 10th century, the chief hydraulic engineer of Merv (now in Turkmenistan) commanded 10,000 workers who built and maintained irrigation canals and dams, and the resulting series of 10 norias and attached mills stands out today as one of the hydrological wonders of the country.

Earlier, in the ninth century, Zubayda, wife of the Abbasid caliph Harun al-Rashid, created a series of wells, reservoirs, and artificial pools that provided water for pilgrims all along the route from Baghdad to Makkah. The route has been called Darb Zubayda (“Zubayda’s Way”) ever since. A century later, enormous floating mills, built of teak and iron, were moored midstream in the Tigris and Euphrates rivers to take advantage of the constant current to grind up to 10 tons of corn a day.

Such scale was not, however, without pre-Islamic antecedents: At Marib in Yemen, one colossal project in the seventh century BC raised a dam 600 meters long and 14 meters tall (1950' by 45'), flanked by sluices, spillways, a settling tank, and a distribution tank. This technological marvel of the ancient world functioned for a thousand years, then collapsed and was rebuilt twice, and finally collapsed a third time, after which its Himyarite engineers lacked the ability to reconstruct it.

All this water management led to the creation of law: Many fundamental tenets of civil and property law across the Islamic world originated in the contentious give-and-take process of establishing water rights. An early example is the Kitab al-Qina, a code regulating water distribution drawn up by Ibn Tahir, the ninth-century governor of Khurasan province in Iran.

“Water tribunals are a much-neglected aspect of Arab civilization,” El Faïz points out, “even though they frequently served as models for social organization.” In a tradition harking back to Islamic rule, one of these tribunals continues today, in Valencia, where elected representatives of the Andalusian province’s eight irrigation grids gather outside the city’s cathedral every Thursday to share out water and settle disputes.

In Cairo, the most elaborate of the “nilometers”—instruments which measured the height of the river’s all-important annual flood—was built in 870; it served until the 20th century.

Although peasants and farmers generally managed smaller installations, major waterworks came under government control. Under the Ayyubids and Mamluks, sultans and large landholders took responsibility for digging and cleaning canals and maintaining dams, according to Salah Zaimeche, an Algerian-born historian of science at Manchester University’s School of Environment and Development in the uk.

Charles Singer, a pioneering Oxford professor of the history of science and the author of a landmark five-volume survey of technology, was one of the first western scholars to acknowledge Arab scientific primacy in the Middle Ages. Writing nearly 50 years ago, Singer contended that during most of the period from 500 to 1500, “technologically, the West had little to bring to the East. The technological movement was in the other direction.” Hill pointed out that a crucial portion of this scientific edge lay in water management, where curved dams, desilting sluices, and hydropower were all Muslim inventions.

One of dozens of rest and water stations on the pilgrim road from Iraq to Makkah, this pool at Aqiq, Saudi Arabia, still holds water more than a thousand years after it was constructed under the patronage of Zubaydah, the wife of caliph Harun al-Rashid.

The Muslims constructed less intrusive, even eco-friendly Water Works as compared to the Romans. “The Moorish peasants found smaller solutions that were largely hidden, subtly transforming the landscape without moving great amounts of terrain,” the Granada professor continues. “If you create a qanat, there’s still a lot of vegetation around what is in effect a small stream.” It was not at all the same scale of engineering required for a stone aqueduct to cross, for example, the 800-meter-long (2625') chasm in Segovia, he explains.

This leaves Islamic hydraulic technology largely a terra incognita in the West. Despite the existence of books and sources on the subject in Arabic and Spanish, only a handful have appeared in English and French. Miraculously, a number of key tracts by Arab scholars from the sixth to the 12th centuries that were translated into Latin survived the destruction of Islamic texts and libraries during the Spanish Inquisition. A number of these documents now belong to the Biblioteca Nacional in Madrid.

https://archive.aramcoworld.com/issue/200603/the.art.and.science.of.water.htm