Ortloff-CJA2005

8/3/2019 Ortloff-CJA2005

1/18

93

Water Supply and Distribution System of Petra

The Water Supply and Distribution System of theNabataean City of Petra (Jordan), 300 BCAD300

Edomite agriculturalists assimilated nomadic tribalgroups familiar with caravan-based trade activities.Although the origins of the Nabataeans remain contro-versial (Taylor 2001; Guzzo & Schneider 2002; Gleuck1959; 1965), their final consolidation in areas aroundPetra in the early third century BCis evident from thearchaeological record. Following conquest by Alexan-der and the later division of his empire, conflicts arose between the Nabataeans, Antigonus of Macedoniaand Ptolemaic forces for control of the lucrative traderoutes passing through Petra. With the decline ofSeleucid and Egyptian influences, a Nabataean stateemerged in 64 BC. Roman intervention began when

Charles R. Ortloff

The water supply and distribution system of the Nabataean city of Petra in southwesternJordan has been explored and mapped. Analysis of the system indicates exploitation of allpossible water resources using management techniques that balance reservoir storage capac-ity with continuous flow pipeline systems to maintain a constant water supply throughoutthe year. Nabataean Petra was founded c. 300 BC; urban development progressed with later

Roman administration of the city starting at AD106; Byzantine occupation continued tothe seventh century AD. Trade networks that extended throughout much of the ancientNear East and Mediterranean world intersected at Petra, and brought not only strategicand economic prominence, but also impetus to develop water resources fully to sustaindemands of increasing population and city elaboration. City development was influencedby artistic, cultural and technological borrowings from Seleucid, Syro-Phoenician, Greekand Roman civilizations; the Petra water-distribution system included hydraulic technolo-gies derived from these contacts as well as original technical innovations that helped tomaintain the high living standard of city dwellers throughout the centuries. Analysis ofthe Nabataean water network indicates design criteria that promote stable flows and usesequential particle-settling basins to purify potable water supplies. They also promote openchannel flows within piping at critical (maximum) flow rates that avoid leakage associatedwith pressurized systems and have the design function to match the spring supply rate tothe maximum carrying capacity of a pipeline. This demonstration of engineering capabilityindicates a high degree of cognitive skill in solving complex hydraulic problems to ensurea stable water supply and may be posited as a key reason behind the many centuries of

flourishing city life.

Cambridge Archaeological Journal15:1, 93109 2005 McDonald Institute for Archaeological ResearchDOI: 10.1017/S0959774305000053 Printed in the United Kingdom.

Positioned between Egyptian, Babylonian and Assyr-ian empires, many influences dominated the formativeNabataean cultural landscape over time. The sacredspring created by Moses, as described in Exodus ac-counts, has been equated with the Ain Mousa springoutside Petra although controversy exists as to its loca-tion (and historical accuracy) and sites in Sinai mustalso be considered. Biblical and Koranic references tothe Petra area document use of water channels andsprings by the inhabitants to maintain agriculture andsettlements. Assyrian texts ascribed to the Sargonic era(715 BC) mention tent cities in this area. The earliestproto-Nabataean period (sixth century BC) began when


2/18

94

Charles R. Ortloff

Scaurus, an envoy of Pompey, sided with Nabataeasenemies to defeat Aretas III in battle (64 BC). Romedeclared the province of Syria under its control, andNabataean-controlled areas were subject to Romaninvasions under Scaurus (62 BC) and Gabinius (55 BC).

Despite the tumultuous political climate, Nabataeanpolitical wisdom prevailed to maintain the establish-ment of an important trading empire with Petra as themain administrative, commercial and religious centre.A series of Nabataean kings (Aretas I, c. 168 BC; AretasII, 120/11096 BC; Obodas I, 9685 BC; Rabbel I, 85/84BC; Aretas III, 8461 BC; Obodas II, 6258 BC) presidedover the expansion of commerce and urbanizationat Petra, driving the citys increasing water needs.Nabataean acquiescence in the inevitability of Romandominance, and the commercial advantages of tradeacross territories consolidated under Roman rule,outweighed the advantages of autonomy. The city

experienced Roman control under Tiberias, Caligua,Claudius, Vespasian and Hadrian, with administrativeconsolidation and territorial status change character-izing Roman dominance. Allied to Rome, Nabataeans,under King Malichus, were participants in suppress-ing the Jewish revolt in AD 67 (Josephus 1960). RabbelII (AD70) then ushered in independence as a Romanally that permitted Petra to continue its trade-basedprosperity. Petra was formally annexed into the Ro-man Empire in AD 106 under Trajan. Throughout thisperiod, caravan trade from Arabia, Africa and the East,with Petra as a key intersection node, sustained the

citys wealth and supported the construction of com-mercial, ceremonial, administrative, manufacturingand water-supply structures commensurate with thecitys wealth and status as an emporium city. UnderRoman governance of Syria, the Nabataeans enjoyedrelative independence, perhaps on account of tax andtribute revenue to Rome. Wealth generated by tradeand taxes on caravans to Cairo, Gaza, Damascus,Palmyra, Jauf, Median, Madain-Salih and Easternlocales, came finally under Roman dominance. Thegradual shift to sea trade (Taylor 2001) led to the de-cline of Petras status as an overland trade centre, withPalmyra now replacing Petra for overland caravan

traffic from Silk Road destinations. Following Araboccupation after the collapse of the Byzantine Empire,the city faded from view until European rediscoveryin the nineteenth century. Further historical accounts(Taylor 2001; Guzzo & Schneider 2002; Gleuck 1959;1965; Hammond 1973; Levy 1999; Auge & Denzer2000; Bowersock 1983; Bourbon 1999; Browning1982) detail the many cultural and developmentalinfluences the city experienced over many centuriesof existence.

Historical background of Petras water-management strategies

It is clear that many exterior cultural, political andtechnological influences colour the history of Petra.

Consequently, the water-supply system may beexpected to reflect borrowings from the best civilengineering practices of neighbouring civilizationsand innovations derived from demands of the com-plex topography and limited water resource base ofthe area. Innovations derived from direct experienceof desert water-conservation measures are also to be expected given the nomadic background of theNabataeans. Egyptian, Mesopotamian, Minoan andGreek civilizations all utilized piping systems forwater supply and wastewater drainage. For example,the Temple at Knossos (Crete) at 2100 BCincorporatedsystems of conical, interlocking, terracotta piping

elements in the main palace water system; later, theHellenic Temple of Artemis (Turkey) dating to 800 BCincorporated strings of socketed, mortared, terracottapipes as well as lead-pipe segments joined by stoneconnectors to transport water from nearby springs.The Hanging Gardens of Babylon, during the reignof Nebuchadnezzar (605562 BC), incorporated a high-level reservoir from which water was delivered toterraces and fountains through hydrostatically pressu-rized terracotta pipelines. Egyptian copper and brasspiping systems associated with 5th Dynasty Templesat Abusir form part of temple drainage systems to

the Nile. Athens in the 67th centuryBC

and Olynthoshad systems of interlocking terracotta pipes sealedby mortar, while the Ionian city of Priene (Turkey) inthe third century BChad elaborate terracotta pipingnetworks complete with filtration systems to purifywater prior to distribution to city fountains (Ortloff& Crouch 1998). In concept, many of these systemsare quite similar to those observed at Petra, indicat-ing some use of previously-established technologiesfrom surrounding societies. New learning gainedthrough years of trade activity to many corners ofthe ancient world would have provided yet furthersources of hydraulic knowledge. An early example

of the Nabataean ability to learn from prior technolo-gies is the 27-km-long Humeima canal from springsin the Sharma Mountains to a Wadi Rum outpost,attributed to Obadas I (9686 BC) (Taylor 2001). Thissubterranean canal indicates that low-angle survey-ing technology was already understood perhaps aborrowing from Greek and Roman geometric tradi-tions (Cohen & Drabkin 1966; Lewis 2001). Combinedwith hydraulics knowledge from earlier sources thiscanal demonstrated it was possible to design a canal


3/18


4/18

96

Charles R. Ortloff

minor Ain Umm Sarab spring. This supply still servesthe modern town and the associated tourist complex(2), (3) located outside the Siq entrance (10). The Siq

is a 2-km-long, narrow passage through the highmountain range bordering the eastern part of the citycore; the steep, canyon-like walls of the Siq provide

Figure 1. Petra site feature map and water-distribution systems.

Key

d = major dams; c = cisterns; T = water-distribution tanks; S = springs

1. Zurraba Reservoir (al Birka) 21. Royal Tombs 41. Byzantine Tower2. Petra Forum Rest House (Modern) 22. Sextius Florentinus Tomb 42. Nymphaeum3. Park Entrance (Modern) 23. Carmine Faade 43. Paradeisos, Market, Hadrians Gate4. Hospital (Modern) 24. House of Dorotheus 44. Wadi Mataha Dam5. Dijn Monuments 25. Colonnade Street (Cardo) 45. Bridge Abutment6. Obelisk Tomb and Bab el Siq Triclimium 26. Temple of the Winged Lions 46. Wadi Thughra Tombs7. Entrance Elevated Arch 27. Pharaohs Column 47. Royal Tombs8. Flood Bypass Tunnel and Dam 28. Great Temple 48. Jebel el Khubtha High Place9. Eagle Monument 29. Qasar al Bint 49. El Hubtar Necropolis10. Siq 30. New Museum (Modern) 50. Block Tombs11. Treasury (El Khasneh) 31. Quarry 51. Royal Tombs12. High Place 32. Lion Triclinium 52. Obelisk Tomb, Snake Monument13. Dual Obelisks 33. El Dier 53. Columbarium Tomb

14. Lion Monument 34. 468 Monument 54. Conway Tower15. Garden Tomb 35. North City Wall 55. Tomb Complex16. Roman Soldier Tomb 36. Turkamaniya Tomb 56. Convent Tombs, Crusader Fort17. Renaissance Tomb 37. Armor Tomb 57. Tomb Complex18. Broken Pediment Tomb 38. Little Siq 58. Pilgrims Spring19. Theatre 39. Aqueduct 59. Jebel MaAiserat High Place20. Uneishu Tomb 40. Al Wuaira Crusader Castle 60. Snake Monument


5/18

97


surges, transient wave structure, flow intermittency,internal oscillatory hydraulic jumps, turbulent dragamplification zones, vapour-pocket formation result-ing from transition between full and partial flowregions). Thus analysis of Petras piping systems pro-vides insight into the available technical knowledgethat was applied to problem solution and the designprinciples that were utilized. Additional considera-tions related to seasonal reservoir and cistern waterstorage and the routing of pipeline paths to achieve

a constant year-round water supply to the city core.This required a bureaucracy to manage the evolvinglevel of complexity. Contour paths had to be surveyedthrough rugged, mountainous terrain, and choicesmade of pipeline hydraulic technical parameters(slope, diameter, internal wall roughness, sinuosity,supply head) to match carrying capacityof the pipesto the spring flow rate. These parameters, as extractedfrom the archaeological record, as well as insights intothe management strategy of these assets, help to as-sess the level of technical achievement of Nabataeanengineers.

The reservoir at Zurraba is an example of the later

phase technological advances (1 in D;2) (Figs. 1 & 2). Itwas constructed to store and transmit water along theWadi Shab Qais (D;2) around the northern flank of theJebel el Khubtha mountain (C;2) in an elevated chan-nel (40 in D;3) containing piping (Fig. 3) that continuedover royal tombs (22, 23, 24 in C;2) to supply a largebasin at its terminus (Fig. 4). This on-demand systemsupplemented the water supplies of the urban core ofthe city (Bourbon 1999). Channels from this basin fedcisterns at the base of the mountain, adding water to

Figure 2. The Zurraba (al Birka) reservoir.

natures preface to the architecturalmasterpieces ahead in the city cen-tre. In early phases of Nabataeanurban development predating theconstruction of pipeline systems, the

main potable water supply derivedfrom an open channel (2 to 2.5 mwide and 1.0 m deep) transportingAin Mousa spring water throughthe Siq (C;1). This channel (dashedline, 29 in B;2) extended through theurban core of the city as far as Qasral Bint (29) with final drainage intothe Wadi Siyagh (A;2). Dam and flood bypass tunnel construction at theSiq entrance, together with infillingand paving of the Siq floor to reduceflooding, has left the channel under

the current pavement surface. Thispavement is attributed to Nabataeanconstruction under Aretas IV and later Roman pavingefforts. The accumulation of flood debris following thecitys abandonment for many centuries, in addition tomodern attempts to dam and infill the front of the Siqto limit floodwater incursion from Wadi Mousa, havehidden this channel. Recent excavations in front ofthe Treasury (11 in C;1) to 5 m depth have, however,revealed remnants of this early open channel as well asearly tombs cut into mountain walls antedating laterTreasury construction. Hexagonal paving slabs and a

water basin existed in front of the Treasury locationin this early phase (Taylor 2001). While this channelprovided water to early phases of the city, the laterconcentration of urban settlement in areas north andsouth of Wadi Mousa (B;2) replete with temple, admin-istrative, commercial and civil structures, indicates atransition towards full city status and a hierarchical,stratified and cosmopolitan society involved in tradeand commerce. This created demands to increasewater supply and distribution to spreading urbansettlement areas resulting from population increase.There was also perhaps a desire to match the citysprosperity from trade with appropriate symbols of

success. Extensive use of pipelines followed to bringlarger amounts of water to areas not reachable by theold, low elevation, open-channel system. Pipelinesystems, however, introduced new design complexi-ties that involved knowledge of ways to maintain astable flow whose maximum (theoretical) flow ratematched (or exceeded) the supply spring flow rate.Flows in poorly-designed pipeline systems are capableof a surprising number of transient, self-destructivehydraulic instabilities (e.g. water hammer, pressure


6/18

98

Charles R. Ortloff

Figure 3. Elevated water channel/piping system on west face of El KhubthaMountain.

that collected from rainfall runoff for urban housingneeds and rituals at nearby tomb complexes. Whilerunoff capture probably supplied the Zurraba reser-voir, local spring sources, including Ain Mousa, werealso important in the early phase of city developmentand may have also contributed water to the reservoir.Although reservoir water could be used to supplementthe Siq channel, Ain Mousa water supplies were laterswitched to a piping system and the open channel

was abandoned. Rainfall runoff and spring flow stillenabled the Zurraba reservoir to supplement the Siqpipeline when required. Although the modern townhas obliterated ancient hydraulic connections to andfrom the reservoir, there is no topographical constraintto a channel path which would have directed reservoirwater into the open channel (or into a later pipelinesystem) to provide supplementary water supply. TheJebel el Khubtha pipeline, by contrast, appears to bethe main outflow path for reservoir water in the areabetween Jebel el Khubtha and Wadi Mataha (B;2, C;2).Surplus water, after filling the cistern, was directed tothe main city fountain (Nymphaeum 42, B;2) through

either a pipeline or subterranean channel. Although notraces of this connection have been excavated, pipelinefragments in the area suggest this connection. Froma systems point of view, the Zurraba reservoir servedprincipally to maintain cistern levels in the royal tombarea by intermittent water release. The Ain Mousaspring, on the other hand, provided the continuoussupply for the Nymphaeum through piping supportedin a carved channel through the Siq (Figs. 5a & b) thatreplaced the earlier open channel. The Zurraba reser-

voir thus served as a backup systemfor rapid delivery of large volumesof water at short notice to the Jebel elKhubtha cisterns and served to aug-ment the continuous, but declining,

water supply to the Nymphaeumfrom the Ain Mousa spring duringdry seasons. The ability to providean on-demand water supply fromthis backup source would havebeen most useful to large caravansentering the city that would placea sudden demand on water supplyand usage.

Pipeline carrying capacityconsiderations: the Zurraba-Jebelel Khubtha system

While a spring produces a givenvolumetric flow rate, the limitation

on how much can be transported by pipeline stemsfrom its technical characteristics (diameter, internalroughness, slope and supply head). Piping designrequires the spring output flow rate to match (orbe less than) the theoretical carrying capacity of thepipeline. Examination of Nabataean pipeline designsyields insights into their ability to understand internalpipeline flow phenomena, and to construct solutionsto overcome problems limiting maximum throughput.

For an upper estimate of the volumetric flow rate thatthe Jebel el Khubtha pipeline system could sustain,it is assumed that the angle of about 0.005 shown bythe elevated channel supporting the pipeline (Figs. 1& 3) corresponds to the critical flow angle (Morris &Wiggert 1972). The maximum flow height within thepiping is at critical depth equal to perhaps 50 per centor more of the pipe diameter. This condition meansthat water flows in open channel mode through thepiping, with an airspace above the water surface, andthat the flow rate is maximum for given diameter andslope. This type of hydrostatically unpressurized flowreduces leakage between socketed pipeline elements,

while providing the theoretical maximum flow rate forlow angle piping functioning in either open channel orfull flow mode. The maximum flow rate permissiblethen would be the critical velocity x piping wettedcross-sectional area. For a fall in channel height ofabout 40 m over the 8 km pipeline path around Jebelel Khubtha, the theoretical maximum volumetric flowrate is about 90 m3/hr for 20 cm diameter piping. Inpractice, owing to the many mortared joints betweenthe 0.3 m terracotta piping segments (perhaps of


7/18

99


the order of 30,000) along the 8 kmlength of pipeline, and assuming,for a (very) conservative estimate,a 50 per cent leakage rate, the de-liverable volumetric flow rate can

be readjusted to at least 45 m3/hr.Good hydraulic practice, however,is to run open channel flow withinpiping at lower, subcritical Froudenumbers (Fr < 1) to avoid flow insta-bilities caused by joint/channel wallroughness and sinuosity resistance.Froude number is defined as Fr =V/(gD)1/2, where Vis the flow veloc-ity, D the hydraulic diameter and gthe gravitational constant. Thus thedeliverable flow rate needs to be ad-justed further downward to produce

a steady, open-channel flow withinthe piping. For Froude numbers ofthe order of 0.60.8, and with leakage

ing design would be a measure of the understandingof hydraulic principles that were required to achievea steady flow rate to the terminal basin in C;2 andwould explain the high elevation of this pipeline (tomaintain a low slope) around Jebel el Khubtha. TheNabataean design, given slope and pipe diameter,closelymatches best practice as its maximum carry-ing capacity lies above the 2040 m3/hr capacity of theAin Mousa supply spring assumes to be a possible

(intermittant) supply source to the reservoir. It alsoprovides for the largest possible flow rate from theZurraba reservoir to meet on-demand large flowrequirements to the city centre. Additional benefitsfrom the Nabataean design derive from use of partialflow in the piping which greatly reduces leakage rateas compared to a pressurized system. Since particlessettle in the reservoir, no particle transport occurs toclog piping this is particularly important as accessto the high-elevation piping (25 m above ground) onthe near-vertical Jebel el Khubtha mountain face (Fig.3) would prevent easy cleaning. The combination ofall these features indicates that much thought and

experience went into the design of this system whichachieved multiple goals that ensured not only systemlongevity but also rapid, stable, on-demand waterdelivery with minimum leakage.

Additional piping led to the Nymphaeumfountain to complete the Jebel el Khubtha circuitfrom the Zurraba reservoir. As the Nymphaeum wasa major water supply to the urban core and marketareas, much effort was employed to guarantee itsyear-round functioning. The Siq piping system was

Figure 4. Elevated settling basin typical of the El Khubtha channel/pipingsystem.

effects included, a deliverable, stable flow rate of theorder of 30 m3/hr could have been directed towardthe Nymphaeum from the Jebel el Khubtha pipeline.If this long piping system were to function in full-flowmode, flow rate would be somewhat less than thatderived from an open channel mode owing to internalwall friction. This generic observation was made in theearly centuries AD (Vitruvius 1999: . . . for a supplyreservoir water height, long pipe lengths (containing

full flow) diminish water transport amounts due to(cumulative) internal flow resistance effects . . .; thisresult has been computationally verified (Ortloff &Crouch 2001; Fig. 2) to quantify Vitruviuss comment.A piping slope less than that observed would haverequired larger diameter piping to match the springflow rate and be subject to greater internal flow resist-ance. With a steeper slope, gravitational accelerationmakes flows supercritical (Fr > 1). Rapid supercriticalflows may be subject to intermittent zones of subcriti-cal (Fr < 1) full flow caused by internal wall roughnessand curvature resistance (causing velocity slowing)as well as transient hydraulic jumps that lead to

pulsations in delivery. Such transient effects can leadto destructive tensile forces that weaken mortaredpiping joints. If flow-rate pulsations are transmittedto both the supplying and receiving reservoir, slosh-ing effects amplify unstable delivery rates. Transientchanges in input head further amplify transient tensileforces and leakage from piping joints. The best pip-ing design is therefore a partially full (open channel)flow at near critical conditions that empties watergently into a terminal reservoir. Selection of this pip-


8/18

100

Charles R. Ortloff

supplemented, as required by occasional demand, bythe long Jebel el Khubtha pipeline from the Zurraba

reservoir.

Supplemental water-supply systems and water-supply redundancy

Cisterns and dams on Jebel el Khubtha (Akasheh 2003)(C;2) captured and stored rainfall runoff. Some of theupper-level cisterns appear to have channels leadingto ground-level cisterns that fed urban housing or fieldareas to the west of Jebel el Khubtha, supplementing

the water supply from the Zurrabasystem. Intermittent springs locatedon Umm el Biyara (A; 1,2) may alsohave been important in ancienttimes; the Arabic name for this

mountain translates as Mother ofSprings. As previously mentioned,the Siq open channel was aban-doned in late Nabataean phases andreplaced by a pipeline system (Figs.5a & b) that extended to the area op-posite the theatre district (B;1) andended at the Nymphaeum. Thus atleasttwo separate supply lines led tothe Nymphaeum to ensure supplyredundancy. The construction ofthe Siq pipeline system is gener-ally attributed to Malichus II or his

predecessors, Aretas IV or ObodasIII, in the first century BCor earlyfirst century AD (Guzzo & Schnei-der 2002). Water demands south ofWadi Mousa were high on accountof the nearby marketplace, theatre,temple and housing districts andsignificant water resources wereavailable from the north side pip-ing systems. A pipeline connec-tion from the Nymphaeum to thisarea was therefore a logical use

of surplus water for developmentof this area. A bridge most likelycarried water from the north sideof the Jebel el Khubtha system inthe El Hubtar Necropolis area (20in B;2) across the Wadi Mousa inthe vicinity of the theatre (19 inB;1) but all traces are lost owing toextensive erosional flood damage.In addition to water delivered bythese means, the theatre supply was

Figure 5a. Piping elements on the north side of the Siq.

Figure 5b. Channel trough on the north side of the Siq for placement ofpiping.

supplemented from large, upper-level reservoirs in theWadi Farasa area and pipelines originating from Ain

Braq and Ain Ammon sources (Fig. 1). These againindicate built-in supply redundancy from multiplesources. Some of the larger reservoirs, therefore, ap-pear to function in connection with a spring supplysystem and are situated to collect seasonal rainwaterrunoff. Reservoirs, therefore, were mainly to providewater for occasional peak requirements through pip-ing or channel systems. Surface cisterns, on the otherhand, appear to be opportunistically placed to collectrainwater runoff; other than seasonal rain recharge,


9/18

101


the numerous, widely-scatteredcatchments appear to serve localcommunity needs for supplemen-tal supplies of lower-quality waterwhen piped water was not readily

accessible.Traces of a south-side piping

system (Fig. 6) are found in front ofthe theatre. Two parallel pipelinescontinue past the theatre along theridge (B;2) above the commercialdistrict along the Roman Cardo (25),past Hadrians Gate (43) [whoseconstruction is attributed to AretasIV], and the upper and lower mar-ketplaces and the Paradeisos watergarden (Bedal 2004) to locationsabove the Great Temple (28, Figs. 1

& 7) (Joukowski 2001; 2003). Thereit forms part of the water supply tostructures located in B;2. The sys-tem consists of two separate pipe-lines that may indicate branch linesto separate destinations or a laterelevation change that continuesto Qasr al Bint through the GreatTemple to supply the SacrificialAltar area. No excavations exist toconnect the multiplicity of subter-ranean canals below the altar to a

specific water source. HadriansGate (43) separates the secular com-mercial district from the westernsacred temple district containingthe Great Temple, the Temple ofthe Winged Lions (26) and Qasral Bint. The gate reportedly hada gilded door to control traffic between sacred and secular partsof the city. The Paradeisos watergarden west of the gate consistedof an open house situated on a plat-

workshops (Browning 1982) close to the containing

walls of Wadi Mousa before final discharging intothe Wadi Siyagh. This is indicative of measures to usewater in consecutive downhill structures. Distributedalong this piping system, a number of elevated basins(T in B;2) lined with hydraulic plaster (Fig. 8) servedas receiving basins; earth-fill mound structures extendfrom the tanks to the lower Cardo area and servedto support the pipeline. As the basins are elevatedat a height of 20 m on a bluff above the Cardo, therewas sufficient head to provide pressurized water for

Figure 6. Dual pipelines continuing past the theatre to supply tanks (T)above the Cardo.

form island within a large water-filled basin. Bridge

structures connected the island to outer precincts andgreenery added to the citys elegance as indicated byreconstructions reported by Bedal (2004). Strabo (2000)mentions that the city . . . contains many gardens . .. consistent with recent excavation results. The basinwalls contain overflow channels as well as supplypiping that may emanate from both the Nymphaeumvia a bridge connection and from a south side springsupply system. Overflow water from the garden maythen have been directed to lower baths, chambers or

Figure 7. Great Temple on the south side of Wadi Mousa.


10/18

102

Charles R. Ortloff

fountains and basins in the market area below as wellas for the Great Temple (and possibly Qasr al Bint).

Since the south side of the urban core containsthe marketplace area, water requirements were high;consequently, additional supplies were channelled tothis area by means of an underground channel (B;1;B;2).This drew combined flows from Ain Braq andAin Ammon about 5 km southeast of the urban corealong the sides of the Wadi Farasa to the southern partof the city. Some, as yet, unexcavated branch of this

system running through high-elevation channels maybe part of the system that provided water to pipingin front of the theatre. Water from these springs mayhave been supplemented by elevated cisterns in theJebel Attuf area (B;1) in one of the many high places(12, 13 in B;1) of the city. Water for the Lion Fountain(14 in B;1) and al Hamman sacred pool area in thevicinity of elite tombs (16, 17, 18 in B;1) came fromthis supply line, which then continues on to the GreatTemple area. It is clear that a continuous spring sup-

ply was part of the system from large elevated cisternon a plateau above the Tomb of the Roman Soldier(16 in B;1) (Browning 1982) also contributes rainfallrunoff water to this system. Details of the Wadi Farasawater system in this area (B;1) have been investigated

(Schmid 2002) and include large reservoirs and pipingsystems that not only serve local areas, but also havesufficient capacity to transfer water further west tothe Great Temple area. Numerous channels, pipelinesand multiple cisterns within, and leading from theGreat Temple, indicate that water supplies within thetemple were abundant (Joukowski 1999; 2001; 2003).Pipelines from the Great Temple to the marketplacearea and the Qasr al Bint region served as part ofthe water system. Ain Braq, Ain Ammon, the springin Wadi Turkamaniya, multiple cisterns as well as apipeline that may have crossed Wadi Mousa from thenorth side all contributed water to the Great Temple

and Qasr al Bint districts. A bridge abutment (45 inB;2) on the north side just west of the Temple of theWinged Lions contains some piping elements. Thesemay represent just such a connection but the totalconfiguration cannot be confirmed without furtherexcavations.

Cognitive decisions: water-supply system networkmanagement operations

The incorporation of piping networks transformedthe water system to meet the demands of a large ur-

ban population (estimated to reach 30,000: Guzzo &Schneider 2002). The Nabataean water system incor-porated both intermittent, on-demand supplies pipedfrom large reservoirs or drawn from cisterns and con-tinuous supply systems from remote springs to pro-vide the daily requirements of city inhabitants. Thesesupplies were consciously regulated to meet demandfluctuations arising from special events in differentareas of the city, superimposed upon daily require-ments delivered to urban fountains. Water supplieswere brought close to population concentration areasso that all were only a few minutes walk away fromfountains or supply basins. Regulation of the system

required bureaucratic oversight, as decisions regard-ing storage or release needed not only day vs nightbut also seasonal adjustments. Efficiency dictated thatno water could be wasted. As a consequence, transferpiping from north-side systems (Jebel el Khubtha andSiq pipelines to the Nymphaeum) provided water thatcould be transferred to south-side downhill locationsfor further usage or storage before final dischargeinto the Wadi Siyagh. In addition to spring systemsmentioned thus far, water from springs in the Wadi

Figure 8. Fragment of one of the elevated water-

collection basins (T) above the Cardo area.


11/18

103


Kharareeb and Wadi Maaiserat north of the city mayalso have been channelled as far as the Great Templeand Qasr al Bint areas although excavations have notyet verified the total configuration of pipelines andchannels. Additional water supplies were available

from the spring at Wadi Siyagh (A;2) and elevatedpiping or channel systems above tomb facades eastof the Wadi Siyagh spring may also have fed waterto a large terminal cistern (A:2) in addition to pipingoriginating in nearby wadis containing springs. Anelevated channel probably supplied large cisterns inthe area from either rainfall runoff collected behinddam structures or through connection to the springsin this vicinity. The Wadi Siyagh spring, even today,is adequate for the local needs of scattered rural set-tlements in this area. The picture thus far developedis one of: a) exploitation of major springs for continu-ous supply of water to multiple city locations by long

pipeline systems; b) reservoirs and cisterns rechargedby spring input and runoff; and c) reservoir-pipelinesystems designed so that supplemental reservoirwater can provide on-demand release for specialevents or high seasonal demand. Such a well-plannedsystem required equally well-planned managementthat involved measurement of stored water as wellas flow rates. The simple rectangular geometry ofmajor reservoirs made water volume easy to calculate.Measurement of flow rates may have used techniquesdeveloped by Hero of Alexandria (Ortloff & Crouch1998) in previous centuries.

To add to this complexity, dam-based waterstorage presents yet a further aspect of Petras watersystem. On the north side of Wadi Mousa, numeroushigh-status structures in the B;2 quadrant [Temple ofthe Winged Lions, Royal Palace (41), North DefenseWall and Fortress (35), Conway Tower (54)] are logicallyassociated with a dam (d) at Wadi Turkamaniya (B;2)that may have trapped and stored sufficient runoff toprovide water to the lower reaches of the Temple of theWinged Lions, although no excavation data is available.Prior excavations, however, reveal that lower portionsof both the Temple of the Winged Lions and the GreatTemple spanned the Wadi Mousa stream by a bridge.

A destroyed bridge abutment nearby contains pipe-work that may have transferred water from the southto the north side of the city (or vice versa). Supply re-dundancy, achieved by laying pipelines from differentwater sources that crossed from one to another part ofthe city, is an aspect of the Nabataean design approach.This design philosophy ensures that water supply toany area may be composed from different sources depend-ing upon variations in individual spring flow rates andreservoir or cistern supplies. Management oversight

must have been in place to monitor and to control thesystem network efficiently.

While cisterns are well dispersed through theurban settlement area, local sources describe a mainunderground channel starting from Ain Bebdbeh

north of (D;3) and proceeding toward the convergenceof Wadi Mataha and Wadi al Nassara (B;2), then run-ning into the lower north side below the temple areas.The complete channel, mentioned by Taylor (2001),has not been fully explored but certainly added ad-ditional water supply to the north side.

The Nabataean mindset sought to utilize all waterresources. On-site dams constituted yet further com-plexity to water management. Local histories mentionthe existence of large dams one on the Wadi Mataha(Taylor 2001), the other on the Wadi al Nassara (Fig.1). Remains indicate that these dams provided waterstorage from rainfall runoff within urban Petra. Most

likely, dams were in place in other wadis to store waterand to limit erosion or depositional problems withinthe urban environment. The water stored behind damsadditionally served to raise the water table, supply-ing wells as a backup for the cisterns. A well existsin the Byzantine church east of (45 in B;2), and theremay have been others; as yet, none are reported fromthe limited excavation data. Judging from Nabataeanplacement of the Wadi Mataha dam (d in B;2), it musthave been an additional third backup water source tothe Nymphaeum. Since the Ain Mousa spring couldalso serve to fill the reservoir behind the Wadi Mataha

dam through the Wadi Shab Quais pipeline branchfrom Zurraba, the water level behind the dam couldhave maintained a sufficient level to provide backupwater to the Nymphaeum throughout the year. TheNymphaeum could therefore be fed by water fromthe Wadi Mataha dam, by canal or pipeline from AinBebdbeh, by the pipeline along the western face ofJebel el Khubtha, and by the north side Siq pipeline.This degree of redundancy indicates that planning for wa-ter-supply variations was a foremost consideration. It wasaddressed by a complex design that could tap into variouswater resources depending upon relative availability. Theredundancy guaranteed that if one of the supplies

failed, others would be in place to guarantee waterdelivery to the urban core throughout the year. Theredundant supply for the Nymphaeum illustratescognitive planning to maintain the citys market andtemple areas throughout the year, despite summerheat and lack of rainfall. The ingenuity of the Naba-taeans must have been apparent to visiting traderswho spread fame of the citys wealth, architecturalaccomplishments and water-management expertiseto far corners of the known world.


12/18

104

Charles R. Ortloff

Flood control, groundwater recharge and the GreatTemple water subsystem

Floodwater drainage during the rainy season wasa major concern. Since heavy rainfall and flooding

characterize the Petra area, measures to divert WadiMousa floodwater from the Siq by means of a bypasstunnel (8 in C;1), a low dam at the Siq entrance andraising of the Siq floor near the entrance providedflood control. While this strategy had proved effec-tive in deflecting small floods, deliberate infillingand accumulating flood deposits in the Siq continuedto help protect against floodwater incursion. Largeflooding events caused damage, but there were alsoingenious ways to utilize the sudden water bounty.Storage dams across the numerous wadis intersect-ing the urban core served to reduce floodwater entryinto the city while seepage from the impoundments

recharged the water table allowing for wells duringprotracted drought. Thus some of the seepage fromdam storage, canals and pipelines could be recapturedand used as (groundwater) defence against droughton a citywide basis.

The same idea could also be used on a morelocalized basis for elite structures. Within the GreatTemple, an elaborate drainage channel system col-lected rainfall seepage and directed it to a nearbyunderground cistern with 50 m3 capacity (Joukowski2001) located within the upper part of the templestructure. A channel from the upper part of this cistern

conducted overflow water to lower level structuresbefore exiting to Qasr al Bint and Wadi Siyagh. Largechannels in an upper room south of the Theatron(Joukowski 2003) of the temple most likely indicatethe terminus of a subterranean channel from the AinBraq/Ain Ammon system (B;1, B;2). Additional watersources may have been available from springs in WadiKharareb and Wadi MaAisert (Fig. 1) although intactpiping has yet to be fully explored. Channel water,supplemented by cistern water to meet peak demands,was distributed to subsidiary open cisterns located onthe eastern and western sides of the temple, then viasubterranean channels under the lower temenos plat-

form to rooms near the temple entrance stairway. Thusthe cistern functioned as a reservoir adding storedrunoff and southmost outer wall seepage water to thechannel-delivered supply when required much inthe same way as previously-described reservoir-pipe-line systems worked in tandem to meet occasionalpeak demands. Here the system is contained withinthe temple itself , and its importance as a major canalterminus and water distribution node, is made clearby the complexity of hidden channels, cisterns and

piping. The temple water system, capable always ofproviding ample water supplies for rituals, may havehad special significance to demonstrate the premierrole of religion in the lives of the Nabataeans. Onlylater, under Roman rule, are these supplies used for

more utilitarian purposes, perhaps indicating a Romanpredilection for practical concerns.

Many of the dams (d) shown in Figure 1 arelocated on top of mountains and are meant to storerain water to slow and limit water entry into the siteduring the rainy season. They are not cisterns per sebut rather operate more as opportunistic water storagebarriers to limit water entry onto the site below. Theyprovide yet another source of emergency water supplyas water trapped behind them adds to the conservedwater supply of the city.

Technical innovations characterizing Nabataean

piping systems

The piping systems east of the Great Temple reflect lateRoman modifications to supply additional water formarket and commercial structures along the Roman-ized Cardo. Sections of lead pipe running at the base ofthe platform of the Great Temple continued eastwardtowards this area. Lead piping usually indicates Ro-man manufacture so that identification with Romanmodifications is probable. Low-fired clay pipes withrelatively thick walls and socketed ends are also char-acteristic Roman work. Wall thickness can range from

1 to 6 cm while piping segments range from 30 to 100cm in length. Internal diameter usually ranges from 20to 25 cm for most typical urban pipes and, while theinternal surfaces are generally smooth, the socketedends involve significant constriction of the bore. Ro-man pipe diameters (Vitruvius 1999) are usually stand-ardized throughout areas under Roman occupation;observed Roman piping in Petra generally conformsto standard categories. In contrast, some (but not all)Nabataean piping is made from high-fired clays withthin walls usually on the order of 5 mm or less withpiping lengths of 30 cm or so. Short Nabataean pip-ing segments are often the preferred design as they

conform more easily to sinuous paths and allow fornear flush connections that limit leakage. For applica-tions where piping is laid in long excavated channels(e.g. Jebel el Khubtha mountainside, Siq walls), flushmortar infilling was used to reduce leakage. Whilethe Great Temple is of Nabataean origin, elements ofNabataean piping remain along with Roman piping.Excavations have revealed thick-walled Roman pipingbutted onto earlier Nabataean piping, most likely toshunt additional water to market areas of the Cardo


13/18

105


from Great Temple sources. A furthercharacteristic of Nabataean pipingis that it is usually placed withinchannels cut into stone [includingchannels cut into mountain slopes

(Figs. 3 & 6), Siq walls (Figs. 5a & b)and civic masonry] then mortaredover to yield a water seal and im-proved aesthetics for civil structuresand greater security (protecting thesupply). Subterranean channels arefound elsewhere in the Nabataeandomain (Levy 1999), and the conceptof hiding water channels and sourcesserved as a defensive measure toprotect vulnerable water supplies particularly spring sources distantfrom the city centre.

Nabataean short piping ele-ments are characterized by a relative-ly slight constriction at the junctionand, within the piping interior, bysinusoidal ripple patterns (Fig. 10)with wavelengths of about 1.0 cmand amplitude of 3 mm. Piping in theGreat Temple area and theatre showsrippled interior patterns of this type.Experiments (Walsh 1980; Cary et al.1980) indicate drag reduction for rip-ple geometry similar to that observed

in Nabataean piping elements. Theuse of such drag-reduction methodsin Nabataean piping designs permitsa higher flow rate (on the order of5 to 10 per cent) for the same headthan for smooth interior piping. Thismay constitute the earliest empiricalobservation that minor internal rough-ness in piping can increase flow rate,particularly where connection jointsare smooth. Questions arise as towhether the ripple patterns are de-liberate or simply a byproduct from manufacturing

processes, but their appearance in conjunction withsmoother joint connections may represent a designrefinement to improve flow rate perhaps revealedjust by empirical observation.

The piping system on the north side of the Siq(Fig. 5b) contained four open drinking basins capableof trapping particles, with easy access for removal.Dam systems also served to settle particles to improvewater quality before it was delivered to fountains. Longpipelines (such as the Wadi Shab Qais system) are es-

sentially immune to particle clogging effects since the

upstream reservoir at Zurraba serves as a settling tank.This reservoir appears to have multiple sections thatmay represent some form of internal particle settlingcapability; however, no detailed excavations of silttypes are available. Thus water-quality improvementswent together with reduction of sediments trappedin pipelines and provided substantial benefits to thecontinuous operation of the Petra water system.

If the piping lengths are very long, wall frictionlimits flow rate and increases in pressure head do not

Figure 9. FLOW-3D calculations of a rectilinear model of the Siq piping forentry full flow input flow rates of 1.0 (a), 2.0 (b), 5.0 (c), 10.0 (e) ft/s (0.305,0.610, 1.52, 3.05 m/s) velocity indicating internal flow development for theobserved wall roughness distribution. Figure 9d shows results for smoothinterior piping at 1.52 m/s initial, full flow inlet velocity (inlet at right).


14/18

106

Charles R. Ortloff

translate proportionately into flow rate increases (Or-tloff & Crouch 2001). For this reason, long pipelines,where feasible, are usually interrupted by open basinsplaced along their length, effectively to create shortpiping segments between (cleanable) head basins. Sucha system permits higher flow rates than a continuouspipeline with no intermediate basins. Although thispractice is observed in Roman piping networks (Or-tloff & Crouch 2001), it is probably an innovation ofpre-Roman times. The piping on the north side of the

Siq provided the main potable water supply. The south-side channel, on the other hand, was probably meant foranimal watering purposes and may have been suppliedby a channel from Ain Braq and supplemented from acistern atop the bluffs with a drop hole to this channel(C0, Fig. 1). This may have fed the south-side systemsin the theatre district but it is not possible to verify thisconnection at present.

The Siq piping system flow stabilityconsiderations

Nabataean pipeline design solutions can best be illus-

trated by a computer analysis that reproduces internalflow details. To examine flow stability in the Siq north-side piping, sample computer models were made ofa 1220-m-long section with 14.0-cm-diameter pipinginclined at a 2.5 degree angle with and without internalroughness. The Ain Mousa spring had a high flow ratewhich the Siq piping system must have accommodated.A number of sample FLOW-3D computer runs (FlowScience Inc. 2003) were made for velocities of 0.305 (Fig.9a), 0.610 (Fig. 9b), 1.524 (Fig. 9c), 3.05 (Fig. 9e), 6.10 and

9.15 m/s using the measured slope and wall roughness.One criterion for determining an acceptable flow raterelies on flow stability (i.e. is flow smoothly deliveredto a destination point without pulsations?). A secondcriterion asks if the flow delivered to an open basin can

be successively transported to the next pipeline seg-ment without spillage and if a stable free surface flowexists in the piping that can transfer water smoothly tosequential pipelines interrupted by intermediate basinswithout sloshing. For this to occur, pipeline segmentsbetween basins must have the same resistance charac-teristics, similar internal flow patterns and the sameentry conditions. A third criterion requires that the flowrate is sufficiently high to accommodate urban-core wa-ter needs for a population of 30,000. A further criterionis minimization of leakage. Here partial (internal openchannel) flow is preferable as hydrostatic pressure ef-fects causing leakage are reduced.

The results indicate that flow velocities up to 1.52m/s (Figs. 9 a, b, c), with prescribed wall roughness asshown in Figures 5a and 10, produce an open channelflow within the piping but with an apparent unsteadydelivery rate. This is manifested by random waterpeaks that translate down the piping leading to anunsteady delivery resulting in possible sloshing andspillage in open basins along the length of the piping.For piping with a smooth interior at this flow rate asmooth delivery flow rate can be achieved (Fig. 9d),but at the expense of a longer pipeline segment ex-posed to hydrostatic pressure and increased leakage.

At a higher 3.05 m/s flow velocity (Fig. 9e), effects ofthe roughness-induced, randomly-distributed waterheight changes disappear over much of the pipinglength leading to smooth free surface flow. This highspeed flow turns back to a full flow after nearly 1200 mowing to cumulative wall friction effects (Fig. 9e). Thisnegative feature can, however, easily be removed bythe head reset feature so that shorter length pipe seg-ments connect open basins with open channel flowsup to 400 m in length. This would require at least fournorth side basins within the Siq. Without open basins,an uninterrupted pipeline would contain an unsteadyflow and require a large downstream settling basin

to trap particles before further distribution. The Siqexcavator (Bellwald 2004, pers. comm.) has recentlyconfirmed that there are four open basins within theSiq. These would hence not only have provided drink-ing water for entrants to the city but also provided anelegant yet practical solution to the problem of flowstability. Water velocity ofc. 3.0 m/s is adequate toprevent major instabilities and since the supercriticalflow fills about 25 per cent of the piping cross-section(at normal depth) and allow a (very conservative) 50

Figure 10. Typical rippled wall pattern within theinterior of Nabataean piping.


15/18

107


per cent for leakage, spillage and evaporation, thenthe deliverable Siq flow rate approaches 36.0 m3/hr,well withinthe maximum Ain Mousa spring flow rate.Since the (on-demand) Wadi Shab Qais water-supplycapability can be around 30 m3/hr, maximum north-

side water supply that could be carried through thesetwo piping systems is estimated at about 60 m3/hr.Some control over entry flow rates into each pipingsystem must have been in place, and the storage orrelease of the Zurraba reservoir must have been ad-justed in line with seasonal spring or runoff supply.The predicted 35 m3/hr flow rate is consistent withcurrent-day Ain Mousa flow rates (Markoe 2003) of2040 m3/hr although past rates cannot be knownwith certainty.

The Siq and Jebel el Khubtha pipelines are ofdifferent designs and demonstrate the ability of Na-bataean engineers to produce designs to suit different

purposes. While the Jebel el Khubtha and Siq pipingsystems have a 7X slope difference (the former byselective design, the latter dictated by topography),the presence of head reset basins for the Siq systempermits use of short piping lengths to maintain lowflow resistance, and so sustains a high flow rate.Although Siq piping internal open channel flows aresupercritical (Fr > 1) owing to the steep slope, there isno possibility of achieving near-critical maximum flowrates given the slope and diameter of the pipes. Thenet result is a design that meets criteria for a high flowrate and delivery stability. The long, uninterrupted

Jebel el Khubtha pipeline maintained a high subcriti-cal (Fr < 1), open channel flow that gave a large flowrate without instabilities. The Zurraba reservoir actedas a settling tank to remove particles, and the lowvelocity of 1.25 m/s provided stable delivery, a flowrate close to the maximum theoretical value, reducedleakage, elimination of clogging effects and sufficientheight at the terminal basin to supply further piping.The hydraulic design differences of these two pipe-line systems indicates an understanding of differentdesign options for different flow problems. The factthat few, if any, Roman additions were made to thewater-supply situation may be an indication that the

Nabataeans had already exploited all available watersources and that Roman technological improvementscould not significantly improve upon existing Naba-taean technologies.

Petra per capita water availability compared toRoman standards

For estimates of total water flow into the city, we mayconservatively assume a north-side supply approxi-

mately one third that of the south-side rate owing tothe less robust south-side springs. Assuming a com-bined flow rate between the Siq and Wadi Shab Qaisreservoir release lines to be about 40 m3/hr, then thecity could receive at minimum an estimated 50 m3/hr

from these sources. Additional sources [Ain Braq (0.8m3/hr), Ain Dabdabah (2.5 m3/hr), Ain Ammon andAin Siyagh (


16/18

108

Charles R. Ortloff

may have found use in later hydraulic planning by theNabataeans particularly to match spring flow rateswith piping flow rate capacity.

Nabataean overall water-system design strategy

Early use of spring-fed pipelines in Hellenistic citiesof Ionia, mainland Greece and the Greek colonies(Crouch 1993) and in contemporary Roman cities in-dicates that pipeline technology was well developedin many parts of the ancient world and was avail-able for assimilation into Nabataean water system.The Nabataean systems, however, are unique in thatwater conservation is practiced on a much larger scaleand intermittent supplies from seasonal rainfall wereexploited to sustain the city through dry seasons. In es-sence, the Nabataeans utilized all possible above-and-belowground water supply and storage methodologies simultane-

ously. While water storage in contemporary Hellenisticcities also emphasized cisterns for household use, thePetra systems advanced this technology to citywidesystems with elaborate dams and cisterns that servedboth water storage and flood control purposes. Waterstorage in aquifers was promoted through dams; thisallowed for use of wells as a backup system should allother supplies fail. Provided a cistern could be madedeep enough, it would be resupplied from groundwa-ter, a technique well known in Bronze and Iron Agecities of the Near East.

Summary and conclusions

A comprehensive water-supply system of dams,cisterns, channels and pipelines exploited springs aswell as rainfall runoff. While some of the technologymust have been borrowed from contemporary cit-ies, the limited water resources at Petra, combinedwith the complex topography led to innovations inthe use of water-storage methodologies on a citywidescale where stored runoff water provided a size-able fraction of yearly requirements and served asa backup to the many springs. Examination of twodifferent pipeline systems with very different slopes

and delivery requirements (one on-demand and theother continuous flow) indicates that technology (andexperience to employ it) was in place to provide dif-ferent designs that minimized leakage, maximized theflow rate, minimized particle ingestion and cloggingand eliminated transient flow instabilities. The Siqpipeline incorporated water purification by means offour well-placed settling basins which also solved acomplex flow stability problem. The range of solutionsadopted confirms that a hydraulic design methodol-

ogy was in place and was applied with great cognitiveskill to solve complex hydraulic problems.

It is traditional to look for Roman technical ad-vances that improved the Nabataean system, but feware found. This indicates that Roman engineers may

have viewed the Nabataean system as near-optimum.In that case, it is likely that the several water-man-agement techniques observed by the Romans mayhave been borrowed by them and applied to theirdesert cities and outposts. It is clear that the successand longevity of Petra depended upon its innovativewater-system design which in itself constitutes a vitalchapter in the history of water management in theancient Near East.

C.R. OrtloffCTC/United Defense

Santa Clara, CA 95050

USAEmail: [email protected]

References

Akasheh, T., 2003. Nabataean and modern watershed man-agement around the Siq and Wadi Mousa in Petra,in Hashemite University Report, The Hashemite Uni-versity, Zarqa, Jordan. Zarqa: Hashemite UniversityPress, 115.

Auge, C. & J. Denzer, 2000. Petra, Lost City of the AncientWorld. New York (NY): H. Abrams, Inc. Publishers.

Bedal, A., 2004. The Petra Pool-Complex: a Hellenistic Paradei-

sos in the Nabataean Capital. Piscataway (NJ): GorgiasPress.Bourbon, F., 1999. Petra, Art, History and Itineraries in the

Nabataean Capital. Rome: Grafedit Publishers.Bowersock, G., 1983. Roman Arabia. Cambridge (MA): Har-

vard University Press.Browning, I., 1982. Petra. London: Chatto & Windus Pub-

lishers.Butterfield, R., 1964. Ancient Rome. New York (NY): Odys-

sey Press.Cary, A., L. Weinstein & D. Bushnell, 1980. Viscous flow

drag reduction, in Drag Reduction Characteristics ofSmall Amplitude Rigid Surface Waves. (AIAA Progressin Astronautics and Astronautics 72.) New York (NY):American Institute of Aeronautics and Astronautics,14467.

Cohen, M. & I. Drabkin, 1966. A Sourcebook in Greek Science.Cambridge (MA): Harvard University Press, 33642.

Crouch, D., 1993. Water Management in Ancient Greek Cities.Oxford: Oxford University Press.

Flow Science Inc., 2003. Flow Science Users Manual. Santa Fe(NM): Flow Science, Inc.

Glueck, N., 1959. Rivers in the Desert. New York (NY): Strausand Cudahy Publishers.

Glueck, N., 1965. Deities and Dolphins. New York (NY):


17/18

109


Strauss and Cudahy Publishers.Guzzo, M. & E.E. Schneider, 2002. Petra. Chicago (IL): Uni-

versity of Chicago Press.Hammond, P., 1973. The Nabataeans Their History, Culture

and Archaeology. (Studies in Mediterranean Archaeol-ogy 37.) Gothenburg: Gothenburg Publishers.

Josephus, 1960. Complete Works (The Antiquities of the Jews,The Wars of the Jews). Grand Rapids (MI): KregalPublications.

Joukowski, M.S., 1999. The Great Temple, in Brown UniversityExcavations 19931999, vol. 1. Providence (RI): BrownUniversity Publications, 245.

Joukowski, M.S., 2001. The Great Temple of Petra, in Ar-chaeology in Jordan, 2001 Season, eds. S. Savage, K.Zamora & D.R. Keller. American Journal of Archaeology106, 43558.

Joukowski, M.S., 2003. Petra: the Great Temple Excavation,2002 Field Campaign. Providence (RI):Brown Univer-sity Report.

Levy, U., 1999. The Lost Civilization of Petra. Cambridge (MA):

Floris Books.Lewis, M.J.T., 2001. Surveying Instruments of Greece and Rome.

Cambridge: Cambridge University Press.Markoe, G., 2003. Petra Rediscovered. New York (NY): Harry

N. Abrams, Inc. Publishers.Morris, H. & J. Wiggert, 1972. Applied Hydraulics in Engineer-

ing. New York (NY): The Ronald Press.Nehme, L., 2000. The world of the Nabataeans, in The Levant,

ed. O. Binst. Cologne: Konemann VerlagsgesellshaftmbH, 3763.

Ortloff, C.R. & D. Crouch, 1998. Hydraulic analysis of aself-cleaning drainage outlet at the Hellenistic City of

Priene.Journal of Archaeological Science 25, 121120.Ortloff, C.R. & D. Crouch, 2001. The urban water supply

and distribution system of the Ionian city of Ephesosin the Roman Imperial period.Journal of ArchaeologicalScience 28, 84360.

Schmid, S., 2002. The International Wadi Al-Farasa Project.Basel, Switzerland: Association for the Understandingof Ancient Cultures Report 2002.

Strabo, 2000. Geography , vol. VII: Books 1516. (The LoebClassical Library.) Cambridge (MA): Harvard Uni-versity Press.

Taylor, J., 2001. Petra and the Lost Kingdom of the Nabataeans.Cambridge (MA): Harvard University Press.

Vitruvius, 1999. Ten books on architecture, Book VIII, inThe Loeb Classical Library, ed. F. Grainger. Cambridge(MA): Harvard University Press, 1835.

Walsh, M., 1980. Drag characteristics of V-groove and trans-verse curvature riblets, in Viscous Flow Drag Reduction,ed. G. Hough. (AIAA Progress in Astronautics andAstronautics 72.) New York (NY): American Institute

of Aeronautics and Astronautics, 16884.

Author biography

C.R. Ortloffis Principal Engineer in the Numerical Simu-lation Groups at CTC/United Defence in Santa Clara,California with research interests that focus on use ofmodern computational fluid dynamics (CFD) analysis andtest methodologies to advance knowledge of the hydraulicengineering accomplishments of ancient South American,Meso-American, Southeast Asian and classic Mediterraneancivilizations.


18/18

www.cambridge.org

Ancient MayaThe Rise and Fall of a

Rainforest Civilization

Arthur Demarest

Ancient Maya comes to life

in this new holistic and

theoretical study.

Case Studies in Early Societies, 3

45.00 | HB | 0 521 59224 0 | 390pp

18.99 | PB | 0 521 53390 2

Ancient Jomon ofJapanJunko Habu

An overview of the Jomon

period in Japan (circa14,500

300 BC) within the context of

recent complex hunter-

gatherer studies.


50.00 | HB | 0 521 77213 3 | 348pp

18.99 | PB | 0 521 77670 8

Ancient Cahokia and

the MississippiansTimothy R. PauketatUsing a wealth of

archaeological evidence,

this book outlines the

development of

Mississippian civilization.


40.00 | HB | 0 521 81740 4 | 234pp

16.99 | PB | 0 521 52066 5

Ancient PuebloanSouthwestJohn Kantner

An introduction to the historyof the Puebloan Southwest

from the AD 1000s to the

sixteenth century.


50.00 | HB | 0 521 78310 0 | 336pp

19.99 | PB | 0 521 78880 3

Myths of theArchaic StateEvolution of the

Earliest Cities, States,and Civilizations

Norman Yoffee

This collection presents a new

multi-layered model for the

evolution of ancient societies.

45.00 | HB | 0 521 81837 0 | 292pp

19.99 | PB | 0 521 52156 4

graduatetextbook

forth

comingtextbook

African ArchaeologyThird edition

David W. Phillipson

This book provides the only

comprehensive and up-to-date

examination of African archaeology.

Publication April 2005

c.65.00 | HB | 0 521 83236 5 | 398pp

c.24.99 | PB | 0 521 54002 X

talking your language

Documents

Ortloff-CJA2005