Flash flooding as a threat to settlements even in remote areas

672158 EAU0010.1177/0956247816672158Environment & UrbanizationShort Title research-article2016 Flash flooding as a threat to settlements even in remote areas AMIR GOHAR AND G MATHIAS KONDOLF Amir Gohar is an urban and land use planner and sustainable development expert with nearly two decades of working experience with municipal governments, research institutes, international development agencies, private sector firms and local community organizations. He has worked extensively in areas adjacent to national parks and coastal areas that are designated settlements, dense urban forms, and historic urban centers across the Middle east and Africa. His research focuses on finding the appropriate balance between the trendies of rapid urbanization and maintaining ecological integrity in both dense cities as well as remote nomadic towns. As a doctoral candidate in environmental Planning at uc berkeley, his recent research focuses on understanding tourism development and its direct impact on the environment. Gohar obtained previous degrees in urban & regional planning from cairo university, a Master in urban design from oxford brookes university, and a diploma in Land Management from Institute of Housing & urban development studies from erasmus university. Address: 1070 Jackson street, Apt. 713, Albany, cA 94706, usA; e-mail: amir. gohar@berkeley.edu AbstrAct Desert environments are subject to flash floods in wadi floors, which may occur only once every decade or two in a given wadi (dry channels or valleys, except during rains). In areas of rapid growth, flood-prone areas can become urbanized in the time between floods. Being flat and constituted of sandy sediments, unlike the surrounding terrain, wadi floors are often used for construction, exposing the new settlements to flood risks. We present a case study of the town of El-Sheikh El-Shazli, in the Eastern Desert of Egypt, which has undergone increasingly rapid development over the past two decades. The town is named for an important 13th-century Sufi leader whose shrine receives thousands of visitors annually. We document the extent and effects of the last flash flood (1996) from interviews, field measurement of flood debris, and patterns in satellite imagery; these show the extent of new development in flood-prone wadi floors and the potential risks to residents and visitors in the absence of proper planning. We then recommend measures to reduce the future loss of life and damage from flooding. Keywords El-Sheikh El-Shazli / environment / flooding / Red Sea / sustainability I. IntroductIon The town of El-Sheikh El-Shazli is located in a remote site in the Eastern Desert of Egypt (Map 1). It has a population of about 1,500 inhabitants, primarily local nomads who work shepherding animals or selling local herbs, charcoal or coffee. However, because El-Sheikh El-Shazli is an important religious festival site, the town receives about a million visitors annually, of which up to 300,000 visit during the four-day Eid Al-Adha festival. In 1996, a flash flood hit the entire area and impacted coastal resorts, municipal services, and highways leading to many areas, including to the town of El-Sheikh El-Shazli. El-Sheikh El-Shazli, which sits directly in the heart of the flood path, suffered severe damage as a result of this flood and numerous lives were lost. Since 1996, the town has undergone considerable further development, much of which now constricts or blocks flash flood flow paths, placing more people at risk and exacerbating the severity of potential flood damage. Part of the problem is that the town has grown as a result of immigration from other regions; most of the current residents have little or no experience with flash floods, and do not understand the danger. El-Shazli is not unique in this respect – many other towns in the region are also experiencing rapid growth in areas vulnerable to Environment & Urbanization Copyright © 2016 International Institute for Environment and Development (IIED). Vol 29(2): 503–514. DOI: 10.1177/0956247816672158 www.sagepublications.com 503 ENVIRONMENT & URBANIZATION Vol 29 No 2 October 2017 flash flooding. Thus, insights into the nature of the flood risk in El-Sheikh El-Shazli, along with articulation of potential steps to minimize loss of life and property in future floods through land-use planning, structural countermeasures, and early warning of at-risk populations, could also be applicable elsewhere in the region. The paper draws from four years of extensive fieldwork undertaken in El-Sheikh El-Shazli in two successive projects(1) funded by the United States Agency for International Development (USAID) towards the development of the Red Sea region. This fieldwork involved environmental and social mapping, and included about 60 interviews over these years with government officials, guesthouse owners and local Ababda tribespeople, who have been based in the town throughout its history. Visits to the town took place during the pilgrimage festival high season as well as at other times of year. The research also drew on topographic maps and satellite images, and involved considerable surveying and inspection of the area to determine the extent of the land covered by the 1996 flood. MAP 1 Location of el-sheikh el-shazli SOURCE: Esri online maps with cities plotted using GPS survey data. 504 G Mathias (Matt) Kondolf is a fluvial geomorphologist and environmental planner, specializing in environmental river management and restoration. As Professor of environmental Planning at uc berkeley, he teaches courses in hydrology, river restoration, and environmental science. His research focuses on human–river interactions, with an emphasis on managing flood-prone lands, managing sediment in rivers and reservoirs, and river restoration. He has served on national Academy of science panels, the calfed ecosystem FLAsH FLoodInG As A tHreAt to settLeMents restoration science board, the environmental Advisory board to the chief of the us Army corps of engineers, and as clarke scholar at the Institute for water resources of the us Army corps. He has provided expert testimony before the us congress, the california legislature, the california water resources control board, the International court of Justice (the Hague), and in various legal proceedings in the us. Address: e-mail: kondolf. berkeley@gmail.com 1. First project: Red Sea Sustainable Tourism Initiative (RSSTI) from 2001–2005; second project: Livelihood and Income from the Environment (LIFE) from 2005–2008. II. FLoods And eL-sHeIKH eL-sHAzLI a. Physical setting and flash floods El-Sheikh El-Shazli is located in the Red Sea Mountain Range. It is located about 185 kilometres east of Aswan and about 140 kilometres southwest of the city of Marsa Alam, within whose administrative district it lies. The town is located at the confluence of four wadis (dry channels or valleys, except during rains), at the upper reaches of Wadi al-Kharit, which drains westward to flow into the Nile just downstream of Aswan. The landscape is characterized by relatively flat wadi floors bounded by un-vegetated, weathered bedrock mountain slopes that rise steeply from the wadi floors. The town falls within the administrative authority/boundary of Marsa Alam City, meaning that the El-Sheikh El-Shazli mayor reports to the Marsa Alam mayor, who in turn reports to the governor of the Red Sea Governorate, located in Hurghada. In theory, the central government, represented in different ministries, and these levels of local government are together responsible for the development of infrastructure. However, in practice, the remoteness of the town and its disconnect from the grid, the water network, the telephone network and all other means of communication, except the asphalt road, mean the central government (with its ministries of water, electricity, housing, tourism and communication) does not play its role in the same way that it might in more accessible towns. Leadership is left primarily to the local governments at town, city and governorate levels. In addition, Sufi groups together constitute a powerful stakeholder here, with a critical interest in allocating resources to continue developing the area. The town is named for the 13th-century Sufi Sheikh, or religious leader, Abul Hassan El-Shazli. On his last pilgrimage to Mecca, he fell ill in the desert in a place then called Humaithara, where he died in the year 656 (1258 in the Western Gregorian calendar). During the annual Mouled celebrating the Sheikh’s birthday, hundreds of thousands of visitors converge on the site. The town’s log-book shows that it can receive up to 300,000 visitors during this specific Mouled and more than 3,000 visitors on any of the other Mouleds or other spiritual events during the year. The wadi floors offer the only relatively flat surfaces for simple, nonengineered building construction, and for pitching tents of visitors. Wadis are dry watercourses that flow only rarely, in direct response to intense rains, and usually in sudden, potentially destructive, flash floods. Because rains sufficient to produce wadi flooding occur in this region only every decade or so, most of the time the wadis are dry. Their lack of obvious flow and their flat surfaces make them attractive sites for development to newcomers to the region, who do not understand the episodic flood regime. While flash floods are natural phenomena that cause little serious damage if unimpeded, structures located unwisely in wadis are vulnerable to damage, and residents and visitors may be killed or injured. This is most relevant in El-Sheikh El-Shazli, where massive development has taken place since the last major flash flood, and where many of the construction decisions have been made by people unfamiliar with the environmental dynamics of the region. The availability of funds and eagerness of the Sufis to expand their presence in the town has been the greatest driver of development, as Sufis have built more and bigger guesthouses as well as the larger mosque around the shrine, not respecting the path of the flash floods as the major environmental threat to these investments. 505 ENVIRONMENT & URBANIZATION Vol 29 No 2 October 2017 This rapid development has happened in the absence of any formal planning or regulatory framework. Construction takes place with, at most, the informal agreement of the town mayor. The mayor – along with officials in Marsa Alam, the administrative centre, and Hurghada, the capital of the Red Sea Governorate – are fully aware of the cultural sensitivity of the site and are generally neutral towards the Sufi groups and their rapid development process. Therefore, in the present arrangement, it is very unusual for there to be any official attempt to limit this capital flow. Nor is there any precedent for local discussion of the practicality of construction plans. The local tribespeople feel helpless to intervene with advice to these Sufi groups, which are often in competition with each other to build bigger and fancier buildings. In addition, the Sufi NGOs responsible for the investments are not permanently based there; they build and depart, leaving representatives to run the facilities and receive guests. Meanwhile, the magnitude and frequency of floods in the wadis are evidently not well understood. Most of the recent development has been sited directly in the main path of high-velocity floodwaters, while alternative building sites on higher ground or outside the main path of high-velocity floodwaters have not been utilized for development. With flow paths for future flash floods now constricted or blocked by new buildings, and with large numbers of visitors crowded on the wadi floors during Mouleds, there is a large population vulnerable to flooding, most of whom do not understand their risk. Of the four wadis that converge in the town of El-Sheikh El-Shazli, the largest is Wadi Um Samrah, which drains about 25 square kilometres MAP 2 Aerial view of el-sheikh el-shazli at the confluence of four wadis NOTE: The elevation shown is in metres. SOURCE: Satellite image (QuickBird), overlaid on topographic maps (Egyptian Survey Authority) for elevation. 506 FLAsH FLoodInG As A tHreAt to settLeMents FIGure 1 conceptual illustration of the flood path before and after construction in the town SOURCE: Amir Gohar. 2. Kondolf, G M and H Piégay (editors), Tools in Fluvial Geomorphology, John Wiley & Sons, NewA York. to the north. The next largest is Wadi Um Hiraynah, which drains about 7 square kilometres away, and comes from the northeast. Continuing clockwise, Wadi Umm Dihayse drains about 4 square kilometres from the southeast. These three wadis converge and their combined flow passes through a bedrock narrows, downstream of which the valley floor widens and a fourth, smaller wadi enters from the south (Map 2). The narrow rocky edges of the wadi naturally constrict flow to a width of only 80 metres, and act as a hydraulic control for flow upstream. The constriction at the narrows has become narrower because of the buildings constructed there, and this constriction in any future flood will change the pattern of flood flow, as conceptually illustrated in Figure 1. The constriction would cause floodwaters to back up (termed a “backwater” effect),(2) which would change the pattern and extent of areas affected by floods. The simple shack-like housing of the indigenous Ababda people (pastoral agriculturalists) was originally built away from the natural flood path, but was damaged even so by the 1996 flood, evidently because of backwater flooding from the construction that existed in the narrows even then. Photo 1 shows the typical constellation of shacks that are vulnerable to flooding due to this constriction. The narrows are the site of the shrine to Sheikh El-Shazli, and the site of a new mosque built in 2007, which together constrict flood flow to a width of only about 23 metres. This can be expected to exacerbate the backwater effect and damage to structures upstream. b. the town’s urban structure The urban structure of the town can be classified into four major groups: shrine buildings; housing; service buildings; and guesthouses. shrines In this region there are many shrines of Islamic leaders who were either local or passing by on their way to Mecca. The importance of each Sheikh is apparent in the size of his or her shrine, the number of followers and the 507 ENVIRONMENT & URBANIZATION Vol 29 No 2 October 2017 elaborate structures built around the shrine. The town of El-Sheikh El-Shazli houses both El-Sheikh El-Shazli, the main shrine, and el-Sheikha Zakeyya, at which a less important Mouled is celebrated that reportedly attracts some 3,000 visitors. The El-Sheikh El-Shazli shrine is the most significant one, not only in the town but across the entire region. It is hosted inside the mosque where visitors can visit it before and after their prayers. Housing The housing stock in the town is a mixture of government-built one-storey Tawteen buildings (social housing) and local shacks. The Tawteen units, numbering 80 in all, were built between 1990 and 1998 and together house 84 families. There are two types of Tawteen buildings. The first, detached concrete housing, of which there are 60 units, was built in the first two phases without consultation with the local tribes (the main users). Building materials and the lack of adequate ventilation make the units unsuitable to the high temperatures; nor does the layout conform to local needs in terms of privacy for women or space for basic livestock needs. The second type is newer and has been used in other settlements in the Red Sea region as well (i.e. Abu Ghosun Village), but residents still consider it inappropriate by residents to their local culture and climate. The remaining 320 families live in shacks, the conventional and most widespread type of housing, built by individuals to accommodate their families. These shacks are always a single story, and built from metal sheets, wooden posts and any other available material, as shown in Photo 1. service buildings The service buildings in the town, usually one-storey concrete buildings, range from fair to bad condition. They house the municipal and administrative departments, the school, the youth centre, the women’s centre and other public services. Sahat (guesthouses) Sahat means “open spaces” in Arabic. However, it is used in this context to describe the guesthouses that are built to accommodate visitors who come to town for the religious festivals. These are usually concrete buildings that vary in size and height, and in their style and level of luxury. They are built with donations from Sufi sects in order to welcome PHoto 1 example of typical local shacks for local inhabitants in el-sheikh el-shazli SOURCE: Amir Gohar (2006). 508 FLAsH FLoodInG As A tHreAt to settLeMents PHoto 2 example of some guesthouses (sahat) along the main road in the village SOURCE: Amir Gohar (2005). and accommodate visitors for free. Photo 2 provides a view of the town and the sahat zone, near the Sheikh Shazli mosque. c. the impact of the 1996 flood According to eyewitness accounts, the November 1996 floodwaters came primarily from Wadi Um Samrah, and the main flood flow struck the diesel generator building located on the left (south) edge of the wadi, then turned westward through the narrows. Abdul Kader, vice chief of the Ababda group, reported that the gauge (the level of the water in a narrow wadi) of the 1996 flood had increased over natural levels because building in the narrows had already decreased its capacity at that point. He estimated that the maximum water depth was about 1.5 metres across the wadi upstream of the narrows, which we infer reflected backwater conditions at the peak stage. In the course of interviews with Ababda 509 ENVIRONMENT & URBANIZATION Vol 29 No 2 October 2017 FIGure 2 sizes of typical buildings in el-sheikh el-shazli and boulders carried by the 1996 flood SOURCE: Amir Gohar. residents as well as repeat visitors from different Sufi sects, we learned of no direct observations of debris flows passing through El-Shazli during the 1996 flood or before. It was impossible, then, based on interviews alone, to determine whether flows of debris had reached El-Shazli or whether the flow had been entirely fluvial by that point. Fieldwork and on-the-ground measurements show that the magnitude of the flood reflects the intensity of rainfall and low infiltration rates in these rocky, un-vegetated mountains. We measured two boulders known to have been transported and deposited by the 1996 flood: one measured 1.9 × 1.75 × 1.2 metres, the other 1.9 × 1.75 × 1.1 metres. Assuming a bed slope of 1–2 per cent (based on available topographic maps), the estimated flow depth of 1.5 metres would yield sufficient shear stress to move boulders up to 2 metres in diameter. More detailed topographic information and field evidence would be needed to reconstruct the hydraulic conditions under which the boulders were deposited, but they may have settled at the point where backwater from the narrows caused flow velocities to slow. In light of the channel’s steep slope, it is likely that another flow comparable to the 1996 flood would be capable of deeply scouring alluvial fill (removing soil deposits), transporting large boulders, and destroying badly sited buildings. However, the backwater effect would likely induce depositing of boulders some distance upstream of the narrows.(3) Figure 2 provides a visual comparison of the size of these boulders with the town buildings, both the local wooden shacks and a concrete guesthouse; and Photo 1 shows an example of the typical shacks used by the local inhabitants. d. Flood risks as a threat to the local residents and town investments Flash floods in this region occur as a result of steep topographic gradients and proximity to the sea, from which moist air masses can stall over the Red Sea Mountain Range, producing intense rains, usually between 510 3. Andersen, G L (2007), “Long-term Dynamics of Wadi Trees in a Hyper-arid Cultural Landscape”, PhD dissertation, University of Bergen. FLAsH FLoodInG As A tHreAt to settLeMents 4. See reference 3. 5. Farouk, A (2007), Flood-risk Analysis of El-Sheikh El-Shazli Area, Red Sea, Egypt, Report to the USAID LIFE Project. mid-October and late November. The lack of vegetative cover and the extensive bedrock exposure combine with intensity of rainfall to produce flash runoff. Although the Red Sea Mountain Range receives less than 30 millimetres of precipitation as an annual average, it has a high coefficient of variance – 200 per cent(4) – such that the rain that does occur over the course of a decade tends to be concentrated in a few storms, of which one may be sufficiently large to produce flash flooding. The rains that produce flash flooding tend to affect more than a single drainage basin at a time. The 1996 storm produced floods in wadis over about 200 kilometres of the Red Sea coastline. However, the intensity of rainfall at any time will be locally variable, which means that it is unlikely that multiple tributaries to a large drainage network would be producing their peak runoff at the same time. Even if they did, they would each have different travel times to a downstream point due to different path lengths and gradients. So in estimating the peak discharge likely at a given point in the drainage network, we would be overestimating the likely peak runoff by simply summing the potential peak runoff from multiple tributaries.(5) Assuming a debris flow were generated near the headwaters of Wadi Um Samrah and began moving downstream at a velocity of 2 metres/second, to traverse the 7-kilometre distance to the town would require only an hour. Debris flows triggered at closer, downstream sites would reach the town sooner. e. Flood risks as threat during high peak visitation (the Mouled) According to the Islamic Hijri Calendar, the Mouled Abul Hassan ElShazli occurs each year, in the month of Dhu al-Hijjah, the 12th and last month of the Islamic calendar year. Its date cannot be altered or avoided. Because the Islamic calendar is a lunar calendar, 11 days shorter than the Gregorian calendar used in the Western world, the Gregorian date of the Hajj (pilgrimage to Mecca) changes from year to year, and thus the Mouled migrates later in the calendar each year. The greatest flood risk is when the Mouled occurs in November, December or January. In 2015, the Mouled occurred in the last week of September, but we anticipate a higher level of risk in the next several years. Thus, corrective actions taken today could potentially reduce risk during the higher-risk Mouleds in coming years. The seriousness of the flood risk cannot be overemphasized. If 300,000 people were present on the wadi floors during a flash flood, it would be difficult or impossible to evacuate them all to higher, or at least safer, ground. The paths leading up to the hills bordering the wadi floors are steep and narrow, and at the top of the hill, there is very little flat ground on which to stand or sit. Even if everyone present understood the danger and cooperated with a vertical evacuation, filing up the hill in an orderly fashion, it could take hours to transfer the population to the hills, assuming (which is not the case) that there were space to accommodate them there. If we look only at the wadi area upstream of the narrows and assume that this area would hold only 10 per cent of the peak Mouled population, or 30,000 people, and assume that this population were moved up six paths into the neighbouring hills, it is hard to imagine that the area would be successfully evacuated of all 30,000 in less than an hour. The immediate aftermath of the flash flood would also be problematic, because the paved road connecting the town to the Marsa Alam–Idfu highway would in all likelihood have washed out, so it would be difficult to bring in 511 ENVIRONMENT & URBANIZATION Vol 29 No 2 October 2017 emergency supplies and to transport injured people to Marsa Alam. Moreover, the current health unit building is likely to be damaged or destroyed in a flash flood by virtue of its exposed location. Thus, it is likely that many people injured in the flood would not receive adequate treatment for some time. One persistent issue with public perception of flood risk, early warning, and evacuation is that if a flood is forecast (based on best available information) and the area is evacuated, but no flood occurs, the next warning may not be heeded because people have a false sense of security, having survived one such warning. This would no doubt be an issue in El-Sheikh El-Shazli. III. recoMMendAtIons a. reduce flood risk through land-use planning First and foremost, authorities responsible for managing land use – including both central government represented by the Ministry of Housing, and local government represented by both the city and the governorate – should freeze further development on potentially flood-prone lands. Even on sites where land is allocated for construction, if the sites are in the direct path of high-velocity flood flows, construction should be postponed pending determination of the flood risk, and if the site is determined to be at risk, alternative sites should be designated and provided to the landowner in compensation for removing permission to build on the original parcel. A scientifically rigorous map of flood risk zones should be developed based on field mapping, detailed topography, and hydraulic modelling. The hydraulic model should be run for different scenarios, including 1996 conditions (to be calibrated based on eyewitness accounts of the extent of flooding) and existing conditions, assuming the removal of structures blocking flood paths, and assuming construction of flood control features such as flood walls. However, there are limits to the reliability of hydraulic models, especially in situations like the episodic wadi floods of El-Sheikh ElShazli. So geomorphic evidence from field and air photos, combined with evidence from past floods, should be used with hydraulic analyses to create a map of areas most vulnerable to flooding. Simply stated, the most reliable, safest, and most cost-effective way to reduce flood damage is to avoid building structures in the path of the floods. If local government on the town and city levels does not have the technical capacity to develop such mapping for flood risks zones, then it could be taken on by the governorate office in Hurghada in coordination with central government in Cairo, including the Ministry of Housing and other organizations with GIS capabilities, such as the cabinet Information and Decision Support Center (IDSC). In keeping with the flood hazard analysis, some structural interventions should be considered. For example, the fourth wadi, which enters the town from the south downstream of the narrows, could probably be “trained” with flood walls to divert floods from sites along the margins of the wadi, which could then afford relatively safe sites for camping. (After a flash flood occurs in this wadi, such “safe” areas should be re-evaluated, because the sediment deposited during the flood could build up the bed of the wadi such that it becomes higher than adjacent parts of the wadi protected by the wall. If the bed is higher than this adjacent wadi surface, there will be a higher likelihood that the wall will be overtopped or fail, as the next flood in this wadi seeks the lower-elevation surface.) To the extent possible, structures that block the path of the flash flood should be removed to allow the flood to pass. Where the flood is blocked, 512 FLAsH FLoodInG As A tHreAt to settLeMents PHoto 3 the old mosque built in 1982 (A) and the newly constructed mosque finished in 2007 (b) SOURCES: (A) Amir Gohar (2005); (B) Al-Youm Al-Sabe’a newspaper (2015). it will create more problems and further damage. Unfortunately, the new mosque has been built directly in the flood path in the narrows, and Photo 3 shows a comparison between the location/size of the old mosque and the new one. This is a tragic missed opportunity, but as the mosque is probably there to stay, other opportunities should be sought. The diesel generator building on the south side of the wadi could be moved to a more distant site, out of the floodway, with the added benefit that the noise and diesel fumes would no longer pollute the atmosphere near the shrine. The existing guesthouses immediately upstream of the narrows could be moved to safer locations. Water tanks and other essential emergency supplies should be stored on hillsides, above the areas vulnerable to flooding. Although filling the tanks will require pumping, the water distribution system will be simplified by the gravity-fed supply, and tanks will still contain water and be usable after a large flood, provided that emergency shutoff valves prevent the contents from being lost through failed distribution pipes. Emergency health supplies should be located in sites safe from flash flooding. Building large shelters on the hillsides an easy climb from the wadi floor, perhaps via steps, not only could provide a comfortable, safe place to wait out the rain and possible flash floods, but could also serve as a visible reminder of the flash flood danger. These shelters would require some simple engineering, such as pilings set in the bedrock or a raised platform floor, and could be fitted with parallel rows of benches the length of the shelters. The shelters should be designed in such a way to discourage “colonization” and camping by attendees, so that people’s belongings do not displace people when the need arises. One possibility would be to have the shelters run as coffee houses, so that there is frequent traffic by a wide range of people. A coffee house would provide a comfortable resting place, affording a nice view over the Mouled, and exposing the visitors to signage educating them about flash flood dangers and evacuation procedures. If medical supplies were stored in locked units nearby above flood-prone lands, the shelters could serve as makeshift medical clinics during the post-flood period. 513 ENVIRONMENT & URBANIZATION Vol 29 No 2 October 2017 b. evacuate when floods are likely An early warning system should be implemented for flash flooding. The upper reaches of the Wadi Um Samrah catchments are only about 8 kilometres from the town, so the rain intensities experienced in the town should be similar to those experienced in the catchments. The history of significant rainstorms and flash floods, their spatial and temporal distribution, and transmission/infiltration losses can be used to set thresholds for issuing warnings, as developed in the Sinai Peninsula.(6) Equipment required for such an early warning system would include rain gauges (tipping buckets) both in the town itself and in upper Wadi Um Samrah, about 8 kilometres from the town, telemetered to a receiving station in the town. If rainfall intensity reaches a certain threshold, a siren should be sounded to prompt evacuation. This intervention would be implemented by the local government in the town and the city with direct supervision and technical input from the central government, represented by the Ministry of Irrigation and Water Resources Management. Evacuation routes to be used in the event of a flash flood warning should be identified, designated, and clearly marked. Safe areas should include not only the limited areas on the nearby hilltops, but also marginal parts of the wadi surface outside of the main flood flow that can be protected by flood walls. It is important to educate members of the public who attend the Mouled. Signage could be developed that conveys the risk of flash flooding and where to evacuate, not only in text but also through cartoons understandable to all. The public needs to understand that in a rainstorm they should not only seek shelter from the rain, but also that the main flow path should be evacuated in favour of designated safer zones, be they marginal areas of the alluvial floor or on the bedrock hills above. Finally, safety officers should be empowered for the winter months, when flash floods are most likely. Several members of the community, preferably drawn from the leadership, could be appointed (and provided a stipend) to implement a public education campaign, monitor weather conditions and rainfall intensities, and sound evacuation alarms in the event a flash flood is probable. Once the alarm begins to sound, the safety officers and police should immediately circulate and encourage all people to clear out of the designated floodway immediately. 6. Cools, J, P Vanderkimpen, G El Afandi, A Abdelkhalek, S Fockedey, M El Sammany, G Abdallah, M El Bihery, W Bauwens and M Huygens (2012), An Early Warning System for Flash Floods in Hyper-Arid Egypt. AcKnowLedGeMent Some of the surveys for this paper occurred while working for a USAID project named “Livelihood and Income from the Environment (LIFE)”. reFerences Andersen, G L (2007), “Long-term Dynamics of Wadi Trees in a Hyper-arid Cultural Landscape”, PhD dissertation, University of Bergen. Cools, J, P Vanderkimpen, G El Afandi, A Abdelkhalek, S Fockedey, M El Sammany, G Abdallah, M El Bihery, W Bauwens and M Huygens (2012), An 514 Early Warning System for Flash Floods in Hyper-Arid Egypt. Farouk, A (2007), Flood-risk Analysis of El-Sheikh El-Shazli Area, Red Sea, Egypt, Report to the USAID LIFE Project. Kondolf, G M and H Piégay (editors), Tools in Fluvial Geomorphology, John Wiley & Sons, New York.