THE PLACE OF ANCIENT AGRICULTURAL PRACTICES AND TECHNIQUES IN YEMEN TODAY:

PROBLEMS AND PERSPECTIVES

Sanaa, Yemen

The prospecting carried out throughout this campaign (November 17th to December 4th)* had the aim of affirming whether, in effect, the modulation in size and technical sequence detected in earlier hydraulic prospecting and analyses in the zone of Zafar (the 1998 campaign) were equally discernible in the valleys adjoining the area.

The systems that had been studied earlier (see figure 1) had turned out to be of a size that was noticeably smaller than previous archaeological studies had supposed. (1) It rapidly became obvious that we were, in fact, dealing with hydraulic systems that could be observed in detail with the same resolution that we had used with known al-Andalus systems. Their compactness, technical articulation and size, modulated around a 10 ha area, clearly indicated that the sayl water - the torrential stream that follows the monsoon rains - was concentrated and made to run in a circular fashion, as with any other continuous-flow water. Consequently, procedures for the study of sayl systems could be the same as those used for the study of continuous-flow water. At the same time, the prospecting of Zafar would allow for reasonable predictions to be made with reference to the ordering and functioning of the size of other systems in the area. It was also clear that a consistent widening of the sample of case studies would not only reveal the technical congruency of this stable, agricultural construction, but would also highlight the regularity of population sizes for the peasant construction groups, as expressed by surface area.

The list of asdad (singular: sadd) drawn up by al-Hamdani (in the mid IV H/ X AD), in conjunction with the current commentaries of Muhammad b. Ali al-Akwa , his editor and publisher, have established the orientation of the prospecting. (2) The asdad to which al-Hamdani refers are, in his opinion, already very old, certainly pre-Islamic. Both the architecture and the samples of ceramic ware collected from the surface of the prospect area (Halid al-Ansi, 1999) indicate a Himyaritic chronology.

As a result, there was the opportunity to study the production of extremely old agricultural areas and the technical reasons for their stability and permanence, none of which issues had, to our knowledge, been analysed with clarity to date; it was simply assumed that Islam signified the start of a change that archaeologically had been neither identified nor measured.

The valley of Bayt al-Aswal lies 2 Km from Zafar. The whole valley is organised as a hydraulic complex of converging sequences. Each sequence originated in a sadd. There are 5 of these asdad and they had been inventoried by al-Akwa in his commentaries on al-Hamdani.

The work consisted of prospecting the land in detail on the basis of aerial photography (1:10,000), and of undertaking sectional and elevational planimetric representations of the water containment walls (see figure 3), of some of the terraces, of the irrigation ditches (saqiya-s) of the maqlah-s and other elements of irrigation. Detailed planimetry was also undertaken of all the hydraulic systems, plot by plot, following the entire course of the water through the systems, ditch by ditch and watergate by watergate. This work is carried out on the basis of aerial photography and by tracing the water circuit, since this is not directly visible in the photographs. In addition, the names of all the girab were taken and numbered, and will subsequently be analysed philologically.

The results obtained are the following:

• Sadd Gubayr (N 14° 11. 850; E 44° 25,300) Water from this sadd irrigates 17 girab, with a total extension of 7.3 ha.

• Sadd al-Maliki (N 14° 11. 690; E 44° 25,405) 14 girab, 3.46 ha.

• Sadd al-Nuqaq (N 14° 11. 965; E 44° 24,889) 6 girab, 2.8 ha.

• Sadd al-Amra (N 14° 11. 646; E 44° 25,001) 9 girab, 1.71 ha.

• Sadd al-Umran (N 14° 11. 656; E 44° 25,341) 33 girab, 7.56 ha.

In the map obtained (figure 4) it can clearly be seen that the orientation of the valley's irrigation is based upon two principal systems, both being greater than 7 ha each: sadd Gubayr and sadd al-Umran. The other systems (al-Nuqaq, al-Maliki, al-Amra) are evidently complementary with respect to the irrigation system as a whole, yet they are fundamental in ensuring the compactness of the overall system and in reducing to a minimum the erosive effects of uncontrolled torrential rain.

In fact, the observation of this compactness is fundamental in understanding the sequence of the design and the construction of the sequence. We observe in figure 5 how the al-Gubayr sadd system and its irrigation space constitute the central part both because of their total extension and also because of the singular extension of their terraces. We can also perceive the decisive function of the architecture in underpinning all the valley's linked systems. On the other hand, it is less obvious to perceive that this centrality cannot exist without the sadd al-Nuqaq- (Nuqaq means 'toad'), which diverts, collects and administers one of the strongest sayl water channels in the valley. Al-Nuqaq protects the al-Gubayr terracing. Strictly speaking, it is al-Nuqaq that provides a stable existence for al-Gubayr. To limit ourselves to the observation of al-Nuqaq's size (6 girab, 2.8 ha) or to its apparently peripheral area would be a grave distortion of reality.

In such a way, the observation of the compactness and conditioned stability of al-Gubayr allows us to appreciate that the juxtaposition of these areas cannot have been produced in long chronological intervals. The stable al-Gubayr area requires the contention of the current channels that is carried out by al-Nuqaq. This suggests that the hydraulic organisation within the valley as a whole was conceived as an ensemble, and that its realisation was successive but integrated. We should therefore abandon the commodity of postulating evolutional causality. For example, it is not empirically consistent to propose that the extension of hydraulic areas in the valley was the result of gradual demographic pressure. A better explanation is that of considering the ensemble as a whole, congruent with the size of the initial population. This is not to suggest that all areas created within the valley based on asadd have the same degree of necessity with respect to one another. And in fact the 14 girab (3.46 ha) of al-Maliki o the 9 girab (1.71 ha) of al-Amra are not necessary to the existence of Gubayr or al-Nuqaq. Nor, on the other hand, is it at all certain that the 33 girab (7.56 ha) of al-Umran, as we shall see later in this discussion, are essential to the design, construction and maintenance of al-Gubayr and al-Nuqaq.

This kind of particularly interwoven articulation was foreseeable from the studies of the hydraulic areas of al-Andalus. The novelty lies in the fact that the organisation of the complementarity and compactness of the spaces was undertaken not to control &endash; concentrate and distribute &endash; continuous water currents, but instead was for temporary channels for the monsoon. It is specifically the fact of the monsoon that introduces variations of range in hydraulic circuits, variations that had not been detected in the modest continuous-flow waters of al-Andalus.

In the eastern sector of figure 4, bordering the sadd Gubayr and the first terraces of the Gubayr and Maliki, there are 20 girab the irrigation of which depends on a sadd, Harara, located at a point 2,760 m in the mountains that overlook the valley, which is the true hydrographic nucleus of the basin. The Harara girab are clearly additional to the valley's hydraulic organisational ensemble. Part of the descent water that supplies the girab is collected by the sadd Gubayr itself. The superposed nature of the water collection undertaken by the enormous sadd Harara was evident from the first moment. The sadd had an anomalous appearance, given the unnecessary connection with the valley's hydraulic sequences, the logic of which was clearly discernible. And the monumental nature of this sadd is reinforced by the architectural remains of a small, paved walled site, clearly visible and associated with the sadd, at about 100m distant. It would seem that the sadd Harara was known to the writers of a Himyaritic inscription of the IV H/ X AD, whose context was undetermined, and the geographical origin of which was also unknown. Its final identification, which we were able to carry out, has allowed us to understand the meaning of the 'palatial' inscription, related to the construction of the sadd, in Harara.

Consequently, the sadd Harara, so clearly superposed above the valley's hydraulic ensemble - in agreement with epigraphical evidence - dates at least from the IV H/ X AD. Therefore, the peasants' regulation of the valley is at least as old as this.

Current peasant memory attributes malignity to the waters that fall from the sadd Harara, situated at such a height. According to the peasants now living in the area, this water would be too cold and would damage the sorghum harvest. They also claim that the reflection of the waters in the sadd, so high above, was of such strength that it dazzled the peasants in the valley below, stopping them from working. Whether this is true or not, the opinion - manifestly very old - reveals the perception of this sadd as something external, and that is certainly true. Perhaps we ought to think along the lines of sadd Harara, although clearly external, representing an interference in the hydraulic administration of the valley, since it allowed for the control of the water supply to two of the sadd from afar. One of these, sadd Gubayr, was the most important in the entire valley sequence. It has also been observed that sadd Harara was able to intervene in determining the hydraulic circuits in neighbouring valleys. Far more detailed fieldwork will have to be undertaken in future in order to assess the ways in which the existence of this enormous sadd regulated change in all these valley circuits.

In principle, then, We believe that future fieldwork should be directed at determining how the sadd Harara mediated in all the nearby hydraulic circuits, situated in the valley below. Construction by the Himyarite state of Zafar, or by their client groups, seems initially evident. If this is the case, the order established by the peasants at the bottom of the valley would be prior to the intromission of Zafar in the peasants' hydraulic circuits. Were these circuits not to have existed first, it would have been very difficult to subsequently establish intervention through control of the sporadic sayl channels from places outwith the peasants' ordering. This seems to us, all in all, to be an issue of greater complexity than the usual description of hydraulic areas.

The sequence of hydraulic organisation in the Bayt al-Aswal valley is possible from the systematic use of specific hydraulic knowledge. The empirical recognition of the geography of the channels determined by the monsoon is accompanied by the knowledge of how to construct cultivation terraces. To simplify, we could say that the builders resolve two integrated questions. How to construct an area of cultivation, how to concentrate and distribute the necessary water, and how to avoid the constant erosion of the soil that is involved. The technical expression of this issue is the maqlah, a depression, in the form of a deep channel, transversal to the natural slope, in which the rainwater and channel filtration collected. Its function was to moderate the current flow that is inevitably beyond the control of the channels, and to concentrate the filtration of the irrigation water. The maqlah therefore contributed to the draining of the terraces and constituted a much-needed element of protection for these areas. But they must also have had a primordial function in the process of terrace construction. The maqlah channel is dug into the ground, but on its upper section closest to the direction of the slope, there was usually an upper-terrace contention wall of considerable magnitude, in some cases reaching several metres' width. Their function in the process of construction could be, therefore, that of halting or slowing and accumulating sediment brought along with the channels in order to create a 'terraceable' surface just above the height at which they were situated. The direction of construction in the cultivating area is, then, from bottom to top, causing the deposit of sediments brought along by the channels. For this reason, the siting of the maqlah-s is spaced, at the key points of concentration for the earlier natural current, and may be used in establishing phases of construction. Clearly, they are a device, and may be confused with that of a deep irrigation channel. They seem to establish interstices in the irrigated area, yet do not constitute any type of break with the final circulation of the water (figure 4). In order to better appreciate their importance in the construction and maintenance of the sequence as a whole, we represent only the circuit of connections (figure 6), their role in the construction and maintenance of the terraces and of their drainage being manifestly clear. The maqlah, therefore, is a constructive device combining a great deal of peasant knowledge that was essential both at the moment of its construction and when it began to carry out its function.

There is the opportunity at Bayt al-Aswal to verify the specific use of this device, by excavation. In girab 13 and 14 in sadd al-Umran, three metres underground, there are the ruins of channels dug into the rock that must have constituted an essential construction phase in the process of organising the terrace silting against the direction of the water current. One of the aims of the next campaign would be to verify, by systematic excavation, what are, up to the moment, casual peasant findings.

Similarly, one of the future objectives would be that of verifying up to which point an excavation of a "palace" spatially associated with sad Harara, whose epigraphic name deserves to be kept, might obtain results that would justify the cost of such an excavation.

* Maite Márquez, a graduated student of the Universitat Autònoma of Barcelona, assisted helpfully in the field work.

(1) In reference to this zone, see GIBSON, M.; WILKINSON, T.J., "The Dhamar Plain, Yemen: A preliminary study of the archaeological landscape". Proceedings of the Seminar for Arabian Studies, 25. 1995

(2) Hamdani, Abu Muhammad al-Hasan b. Ahmad al-/Muhammad b. 'Ali al-Akwa (ed. 1986) Al-Iklil. Vol. VIII, Beirut.