Progress Report of the Research 'Assessment of the October 24th
2008 Flood in Wadi Doan, Hadhramout towards Realization of
IWRM'
Prepared By:
Eng. Abdulmoghni A. Alga'fari,
Supervised by:
Dr. Abdullah A. Noman & Dr. Alkhateeb Al-kebsi,
Submitted to Water and Environment Center, Sana'a University,
Yemen
February, 2014
1
Table of Contents
1-ABSTRACT.............................. ................................................................................................................ 3
2-INTRODUCTION.............. ......................................................................................................................... 3
2.1 BACKGROUND ....................................................................................................................................... 3
2.2 STATEMENT OF THE PROBLEM ..................................................................................................................... 4
2.3 THE OBJECTIVES OF RESEARCH ..................................................................................................................... 4
3-LITERATURE REVIEW (OUTLINE).............................. ................................................................................... 5
3.1 GENERAL ............................................................................................................................................ 5
3.2 SITE ACCESS & TOPOGRAPHY ...................................................................................................................... 5
3.3 WADI HADHRAMOUT TRIBUTARIES FLOWS ....................................................................................................... 5
3.4 EARLY WARNING SYSTEMS ......................................................................................................................... 6
3.4.1 Introduction ................................................................................................................................ 6
3.4.2 Early Warning Systems used for the October 24th 2008 Flood ............................................................... 6
3.5 TRADITIONAL FLOOD MANAGEMENT OPTIONS ................................................................................................... 6
3.6 FLOOD REDUCE SYSTEMS........................................................................................................................... 6
3.7 DAMAGE AND LOSS ASSESSMENT IN WADI HADHRAMOUT...................................................................................... 7
3.7.1 Damages: ................................................................................................................................... 7
3.7.2 Spatial Distribution of the Damages to Housing: ................................................................................ 7
3.8 SOCIO-ECONOMIC IMPACT ......................................................................................................................... 7
4-RESEARCH METHODOLOGY.............................. ......................................................................................... 8
4.1 OVERALL RESEARCH APPROACH ................................................................................................................... 8
4.2 HYDROLOGICAL INVESTIGATION AND FIELD SURVEY .............................................................................................. 9
4.3.1 Description of the Program ............................................................................................................ 9
4.3.2 Soil Conservation Service (SCS) Based application of WMS ................................................................... 9
4.4.1 DESCRIPTION OF THE PROGRAM............................................................................................................... 10
4.4.2 Manning Equation Based Application of the FlowMaster ................................................................... 10
4.5 STAKEHOLDERS’ CONSULTATIONS/INTERVIEWS................................................................................................. 10
5-RESULTS AND DISCUSSIONS..................................................................................................................... 11
5.1 RAINFALL DEPTHS CAUSED 2008 FLOOD IN THE STUDY AREA ................................................................................ 11
5.2 ESTIMATION OF OBSERVED FLOOD .............................................................................................................. 11
5.2.1 Using of Manning Method Based on FlowMaster Program ................................................................. 11
5.2.2 Using of Soil Conservation Service (SCS) .......................................................................................... 12
5.3 PREDICTION OF DESIGN PEAK FLOOD............................................................................................................ 13
5.4 FLOODPLAIN DELINEATION ....................................................................................................................... 13
5.5 ESTIMATION OF RUNOFF VOLUME............................................................................................................... 15
5.6 NATURAL REASONS AND MANMADE ACTIVITIES CAUSED THE 2008 FLOOD ................................................................. 15
5.7 INTEGRATED FLOOD MANAGEMENT WITHIN THE CONTEXT OF IWRM ....................................................................... 15
5.8 SOCIO- ECONOMIC AND ENVIRONMENTAL SITUATION IN WADI DOAN ....................................................................... 16
5.9 INTERVIEWS AND CONSULTATIONS .............................................................................................................. 16
6-CONCLUSION AND RECOMMENDATIONS............................ ....................................................................... 18
6.1 CONCLUSIONS ..................................................................................................................................... 18
6.2 RECOMMENDATIONS ............................................................................................................................. 18
7-REFERENCES……………………….. .................................................................................................................. 19
2
1- ABSTRACT
Yemen is a disaster prone country that faces a number of natural hazards every year, the most
important ones being flash floods, the latest extremist flash flood; which occurred on October 24th
2008; hit the governorates of Hadhramout and Al-Mahra after 30 hours resulting in total rainfall of
almost 91 mm caused destruction and damage of public infrastructures and private properties.
Integrated Flood Management (IFM) within the context of Integrated Water Resources Management
(IWRM) approach has been followed to realize the objectives of this research, which aims to assess
the natural reasons and manmade activities caused the October 24th floods, how much water
discharged in Wadi Doan, which was selected as case study, What are the structural measures and
socioeconomic considerations to be undertaken to reduce and manage such floods and what are the
socioeconomic and environmental impacts raised by the flood. The results of this research were, the
observed maximum flood at the outlet of the Wadi Doan is 3850.2 m3/s which conforms to
frequency of 50 years, and runoff magnitude is 164.65 million m3. The socioeconomic impacts
resulted of the flood were damages to the existing water diversion structures and residential
buildings, lashing of agricultural lands and crops, uprooting of palm trees and Loss to beekeeping
properties.
The conclusion of this research, the October 24th 2008 flood occurred due to the 2008 deep
depression, large hilly catchment area, limited covered vegetation, tributaries steep slopes, growth of
prosopis trees in the main stream, lack of protected flood structures, and random buildings of
residential houses on the banks of the main streams.
To reduce flood impacts and manage flood water in an integrated approach, the research suggests,
construction of check dams, stopping farmers of cultivating the flood streams, activating farmers of
cultivating the arable lands with introduction of the agricultural services based on land use program
and involving community people in flood reduction and management actions through formation of
WUGs/WUAs and IC in the Wadi.
1- INTRODUCTION
2.1 Background
Yemen is a disaster prone country that faces a number of natural hazards every year, the most
important ones being flash floods, earthquake, and land- or rockslides. According to the Emergency
Events Database (EM-DAT) approximately 100,000 people are affected annually by disasters
triggered by natural hazards in Yemen. The 2008 Yemen flash floods were caused by the 2008
Yemen Cyclone, hit the governorates of Hadhramout and Al-Mahra after 30 hours resulting in total
rainfall of almost 91 mm caused destruction and damage of public infrastructures such as roads,
electricity network, water supplies and others. Wadi Hadhramout region was the worst off area as a
result of the disaster, having sustained 67.5% of the total damage and losses (WB, et al., 2009).
However, many tributary Wadis in Wadi Hadhramout such as Wadi Idem, Wadi Doan, Wadi Alain,
Wadi Sar,Wadi Shaheer…etc. were damaged of their water diversion structures , lashing of
agricultural lands and crops, uprooting of palm trees and damaged of public infrastructures such as
roads, electricity network, water supplies and destroying of mud buildings. In this research, it was
selected Wadi Doan as case study to represent the other tributary Wadis in Wadi Hadhramout
because it is considered to be the most important and famous of all and the largest tributary Wadis of
Hadhramout, has the largest population, and exposed to significant damage of its infrastructure
through the last flood.
Wadi Doan is located in the western south of Wadi Hadhramout. It runs from the south to the north.
Wadi Doan is the place; where for generations of beekeepers have been perfecting their craft for at
least a millennium. Combined with the dry climate and short flowering season of local plants. Wadi
Doan is accessed through the asphalt road which linked Seiyun with Al-Mukalla city of distance 76
3
km of Seiyun city passing of the historical Shibam city towards the western south part until Hawrah
district, and then the road runs in the south towards Wadi Doan. The main sub Wadis in Wadi Doan
are Wadi Laiman, Wadi Laiser and Hajrain.
To realize the objectives of this research, Integrated Flood Management (IFM), has been applied to
integrate land and water resources development in the Wadi, within the context of Integrated Water
Resources Management (IWRM) with a view to maximizing the efficient use of flood plains and
minimizing loss to life.
In this study the catchment area of wadi Doan is considered as integrated system, which generates
floods hence the hydrological parameters for the Wadi; probable maximum Discharge (PMD), yearly
runoff, land use patterns have been studied. The natural reasons and manmade (socioeconomic)
activities that caused the October 2008 flood have been determined. The structural measures, and
nonstructural and socioeconomic considerations to be undertaken to reduce and manage such floods
in the Wadi have been identified. This research focused on the field investigation/observation,
review the previous literature pertaining of the study area and analysis of obtained data.
A qualitative approach, through the field investigation and discussion sessions with the flood
affected people and relevant sectors, has been used for understanding the natural reasons that caused
the problem, identifying the socioeconomic and environmental impacts raised by the flood and
identifying the structural measures and socioeconomic considerations to be undertaken within the
context of IWRM to reduce the magnitudes of the damages and losses of such floods and to
sustainably exploit the floods water for multipurpose.
2.2 Statement of the Problem
The October, 24th floods hit the governorates of Hadhramout and Al-Mahra after 30 hours
resulting in total rainfall of almost 91 mm (versus 5-6 mm in normal periods), unleashed
massive floods and swept through these areas causing huge destruction and causalities.
Heavy floods caused destruction and damage of public infrastructures such as roads,
electricity network, water supplies and others.
Many tributary wadis in Wadi Hadhramout such as Wadi Idem, Wadi Doan, Wadi Alain,
Wadi Sheer ,…etc. were damaged of their water diversion structures, lashing of agricultural
lands and crops, uprooting of Palm trees and damaged of public infrastructures such as roads,
electricity network, water supplies and others. On the other hand there is insufficient
information about the natural reasons and manmade activities that caused the floods and how
much water discharged from the tributary Wadis in addition to the poor flood management in
the Wadis.
2.3 The Objectives of Research




The research aim to assess the natural reasons and manmade (socio economic) activities
caused the October 24th flood in the study area.
Determine the flood magnitude at the outlet of study area and calculate the flood return
periods (frequencies).
To find the different kind of suitable structural measures to be undertaken to reduce and
manage such flood impacts in the study area.
Identify the nonstructural and socioeconomic considerations within the context of IWRM
approach to be undertaken to mitigate such flood impacts.
4
2- LITERATURE REVIEW (Outline)
3.1 General
Wadi Hadhramout exposed for many historical high floods in the year 1977, 19981, 1989, 1992,
1996 (Komex, 2002) and 2008, floods occur during monsoon season leading to loss of productive
agricultural lands along the Wadis, increasing sedimentation and significant widening of downstream
Wadi bed (MWE, 2006) the Severe highest flood was in 2008 in Wadi Hadhramout where many
tributary Wadis in Wadi Hadhramout such as Wadi Idem, Wadi Doan, Wadi Alain, Wadi Sar, Wadi
Shheer,…etc. were damaged of their water diversion structures, lashing of agricultural lands and
crops, uprooting of Palm trees and damaged of public infrastructures such as roads, electricity
network, water supplies and destroying of mud buildings.
There are several tributary Wadis in Hadhramout such as Wadi Doan, Alain and Amad etc. Doan is
considered to be the most important and famous of all as there are many attractive villages along
both banks of the Wadi, which are considered as excellent examples means city in old Yemenite
language. It is one of the most beautiful Yemeni villages and the most beautiful village in
Hadhramout. It is located in the western part of Wadi Hadhramout, it runs from the south to the north
and it is bounded by Wadi Alain from the east and Wadi Amad from the west.
3.2 Site Access & Topography
Wadi Doan is located on the western side of the main extended Wadi Hadhramout between 835.400
km to 898.220 km Easting and 1630.650 to 1723.670 km Northing. It runs from the south to the
north. Wadi Doan is the place, where for generations of beekeepers have been perfecting their craft
for at least a millennium. Combined with the dry climate and short flowering season of local plants.
Wadi Doan is accessed through the asphalt road which linked Seiyun with Al-Mukalla city of
distance 76 km of Seiyun city passing of the historical Shibam city towards the western south part
until Hawrah district, then the road runs in the south towards Wadi Doan.
Wadi Doan’s catchment area is located in a hilly region, and it has a fan shape in the high parts, the
catchment boundary areas consist of slightly sloped bared hills, small and mid-tributaries are running
through the hills to consist the main longest stream for 102.780 km and general slope of 6 % , with
distance to the site of selected location at Al-Mashhad Area, at coordinates 854.603 km Easting And
1723.544 km Northing, where this location is the narrowest location in the downstream of Wadi
outlet.
3.3 Wadi Hadhramout Tributaries Flows
In the upstream section of Wadi Hadhramout, which is located western of wadis Doan and Idem
outlets, contributes as average four floods each year, two of which at least quiet magnitude which
continue in flowing to reach the mid of the sub wadis and rarely reach the main wadi of Hadhramout.
In irregular seasons contributes as average one flood each year. The plenty of these floods due to the
following reasons:- widen of the sub catchments areas, narrow of the water streams which is higher
in slopes, small agricultural possessions and lack of the water structures (Balatif, 2002).
The reasons of floods occurrence in Wadi Hadhramout due to the Natural reasons, which involve
Topographical Factors ( larger hilly catchment areas, tributaries steep slopes) and Climatic Factors
(Rainfall storms Characteristics; high intensity in short duration, deep depression), Environmental
reasons (predominant soil and vegetation characteristics in the catchments areas of the wadis and
growth of trees of prosopis species (mesquite trees) in the main stream of the wadis which formed
hindering barriers of the runoff led to water to be accumulated and overflow agricultural and
5
residence areas) and Human made activities (random buildings of residential houses on the edges of
the main streams and sometimes in the streams) (Shamsheir, 2009).
3.4 Early Warning Systems
3.4.1 Introduction
Early warning systems are an important means to reduce disaster losses. Damage caused by a
disaster can be effectively contained if disaster warning can be given and communicated to disaster
management departments, decision making officials and to all those who might be affected by a
coming disaster to ensure that everyone is aware of and prepared for it (Wang et al., 2003 in Noman,
et al, 2007).
3.4.2 Early Warning Systems used for the October 24th 2008 Flood
The Government of Yemen used local and national radio and TV warnings to relay bulletins from the
Civil Aviation and Meteorological Authority. The bulletins warned about possible storm but the
intensity and extent of flash flood was not predicted. No other formal mechanism of early warning
and evacuation at the community level was used. Many affected areas did not receive a timely
warning. The field visits revealed that people warned each other informally via gunshots and mobile
phones. Flood-receiving areas warned the settlements situated downstream about the possibility of
flood in next few hours. In many communities in Wadi Hadhramout, a single mobile call received
one or two hours before the flash flood saved hundreds of lives (WB, et al., 2009).
3.5 Traditional Flood Management Options
Traditionally, flood management has essentially been problem driven: usually after a severe flood a
project would be quickly implemented; the problem and its solution seeming self-evident without
giving any thought to the impact such solutions would have on upstream and downstream areas.
Thus, flood management practices have largely focused on reducing flooding and reducing the
susceptibility to flood damage through a variety of interventions. There are a number of different
ways to categorize such flood management interventions. They can be structural and non-structural;
physical and institutional; implemented before, during and after the flood; etc., and these
categorizations overlap.
3.6 Flood Reduce Systems
Reduction of flash floods is achieved either by detention (upstream solutions) or diversion
(downstream solutions) approaches. Detention depends on the construction of storage reservoirs that
are capable of storing (most of) the water issuing from a major flood event, while the diversion
approach entails the direction of flood waters through a safe passage away from areas to be protected
(SSRDP, 2006).
In Wadi Hadhramout the rainfall is rarely and only for short time but of high intensity which causes
of floods. Therefore the running water in streams has not enough time for percolation and to recharge
the groundwater. Thus most of the rainfall water is lost without use. Therefore it is important to
minimise the risks of these floods and to benefit from its water. It is then very essential to find
reasonable solutions and low cost technology to gain and use the rainfall and flood water according
to the environmental and climatic conditions. Especially that the region will be having rainfall
potentials in the future as it is expected according to many studies regarding the effect of climate
change on the region of Hadhramout (Bahumaid, 2013). Convenient simple and cheap management
6
systems to reduce floods can be described as the following:- Designing incomplete low rocky dams,
Using oqum systems and Plants Growing.
3.7 Damage and Loss Assessment in Wadi Hadhramout
3.7.1 Damages:
The housing damage that occurred due to Tropical Storm 3B can be attributed to a combination of
excessive rain and flooding. A total of 2,826 houses were totally destroyed. These include 1,483
houses in Wadi Hadhramout, an estimated 154 houses in Hadhramout Sahel 19, and 45 houses and
1,164 huts in Al-Mahara Governorate. Some 3,679 houses were partially damaged in both
Hadhramout and Al-Mahara Governorates. A large proportion of the structure suffered partial
damages in the forms of cracks and leaks. As a result, a significant number of persons were
displaced, including 23,382 persons (4,129 households) in Wadi Hadhramout alone. The total value
of damage to shelter in both Governorates is estimated at YR 32,348.6 million (US$ 161.7 million).
3.7.2 Spatial Distribution of the Damages to Housing:
In Wadi Hadhramout, most of the structures that sustained damages were made of traditional mud
bricks with stone foundations. The damages that occurred to the structures were caused by a
combination of excessive rain and flooding. For example, in districts like Sah and Tarim, the villages
that were impacted included housing structures that collapsed to excessive rain and water damages
from floods that rose to close to 5 ft in height. The traditional houses built of mud could not sustain
prolonged exposure to water and collapsed after the water level exceeded the height of their stone
foundation, which therefore eroded the mud brick construction. The districts in Wadi Hadhramout
that sustained extensive damages were: Sah, Tarim, Al Qatn, Hawra/Wadi Al-Ayn, Shibam, AlSoum and Seiyun.
3.8 Socio-Economic Impact
The socio-economic impact of floods in the agricultural and fisheries subsectors can be classified
into four broad categories: food supply, employment, income and availability of agricultural inputs.
Food supply in Wadi Hadhramout will decline if the eroded soil, damaged irrigation infrastructure
and damaged irrigation network are not repaired quickly. This will particularly reduce the food for
flood affected farming households. However, this is likely to have a minimal impact on the national
food security since the country depends heavily on food imports even in normal times.
Before the floods, unemployment in the country was close to 16%. Following the floods, agricultural
production, agro-industrial production and activities related to commerce in the rural areas in
Hadhramout and Al-Mahara Governorates are likely to decline. This will increase unemployment
even further. This is likely to reduce household income as well as rural livelihood opportunities. Due
to extensive damage to houses due to floods, many of these households lost stocked seeds, fertilizer
and other agricultural inputs. This is likely to increase cost of production for crops in the
forthcoming season.
The main impact of the disaster (due to an increase in unemployment, decrease in household income
and reduction in livelihood opportunities) will be to increase rural poverty. The overall poverty rate
is 35% in Yemen, which encompasses a 40% poverty rate in rural areas and 21% in urban areas.
Clearly, rural poverty is twice as much as urban poverty. Floods are likely to increase rural poverty
even higher than 40%, particularly in Hadhramout and Al-Mahara Governorates. This is typical of
the poverty impact on any disaster in terms of production loss, reduced labor demand, and reduced
family income. In order to minimize the adverse impact on poverty, the Government of Yemen must
7
put in place safety-net, recovery and reconstruction programs in the flood affected areas as soon as
possible.
Finally, the flood will also have an adverse impact on the environment due to increased soil erosion,
soil contamination, dead animals and loss of vegetation, particularly damage to the perennial fruit
trees. The rural population will face the serious consequences of adverse environmental impact on
top of the macroeconomic and the socio-economic impact of floods (WB, et al., 2009).
3- RESEARCH METHODOLOGY
4.1 Overall Research Approach
Integrated Flood Management (IFM) integrates land and water resources development in a basin,
within the context of Integrated Water Resources Management (IWRM), with a view to maximizing
the efficient use of flood plains and minimizing loss to life. Thus, occasional flood losses can be
accepted in favor of a long-term increase in the efficient use of flood plains. Integrated Water
Resources Management, which, as defined by the Global Water Partnership (GWP), is “a process
which promotes the coordinated management and development of water, land and related resources,
in order to maximize the resultant economic and social welfare in an equitable manner without
compromising the sustainability of vital ecosystems”, is based on the recognition that a single
intervention has implications for the system as a whole. More positively, integrating management
means multiple benefits may be achieved from a single intervention.
For flood management to be carried out within the context of IWRM as shown in Figure 4.4, the
Wadi Catchment should be considered as integrated systems. Socio-economic activities, land-use
patterns, hydro-morphological processes, etc., need to be recognized as constituent parts of these
systems. The linkages between various relevant sectors become very important A participatory and
transparent approach which includes a representative range of stakeholders in the decision making
process is another key component of IFM. Therefore, an integrated flood management plan should
address the following five key elements that would seem to follow logically for managing floods in
the context of an IWRM approach:
Manage the water cycle as a whole;
Integrate land and water management;
Adopt a best mix of strategies;
Ensure a participatory approach;
Adopt integrated hazard management approaches
In view of the above a qualitative approach, through the field investigation and discussion sessions
with the affected people and relevant sectors , has been used as the emphasis of the research is put on
understanding of natural reasons and manmade activities which caused the October 24th 2008 Flood
and it was selected Wadi Doan as a case study because it is considered one of the most important
Tributary Wadis in Wadi Hadhramout, the objective of this investigation to study the hydrological
characteristics of the Catchment of the Wadi (land use, water divide line, soil group, drainage
patterns, the observed maximum flood, the probable maximum discharges of the floods for the
designed return periods of Q25, Q50 and Q100 and yearly runoff ).
Socioeconomic and environmental situation resulted after the flood has been assessed based on the
consultations with the flood affected people and the relevant sectors, and also based on quotation of
the previous studies targeted this aspect. To reduce and manage the floods in the Wadi, suitable
structures and socioeconomic activities have been suggested.
Desk work has been carried out to analyze the data collected from the field investigation and
literature review and processed by application of the software Watershed Modeling System (WMS)
8
to assist in calculation of the hydrological parameters, observed discharges based on the maximum
daily rainfall volume, and calculation of the designed return periods. The FlowMaster Program also
has been used to calculate the observed discharge through cross section was surveyed at the outlet of
the Wadi.
4.2 Hydrological Investigation and Field Survey
Through the field investigation in Wadi Doan, and consultation with area people it was selected the
narrowest location at the outlet of the Wadi to carry out cross section survey by using total station
device to know the cross section area, of which the flood from the whole tributaries of Wadi Doan
was discharged, the selected location was at Al-Mashhad area, at coordinates 855.277 km Easting
and 1723.751 km Northing, where the flood level at this location was observed over the Wadi banks
as soil erosion and flood carry up bed coarse and gravels to highest level where it was marked to be
the highest flood level had been witnessed by the farmers and the area people as shown in the photos
No. A and B whereas photos No. C and D show the erosion occurred of the main stream due to the
2008 flood.
In addition to the land use pattern of the catchment area of Wadi Doan was investigated and a map to
determine the land use patterns for agricultural and residential use has been drawn.
4.3 Watershed Modeling System Program Application (WMS)
4.3.1 Description of the Program
WMS is a comprehensive environment for hydrologic analysis. It was developed by the
Environmental Modeling Research Laboratory of Brigham Young University in cooperation with the
U.S. Army Corps of Engineers Waterways Experiment Station.
With version 7.1 there is a free-ware version which allows you to use the graphical user interface to
set up any of the supported hydrologic models (an image can be placed in the background for
presentation). A license must be purchased in order to use digital elevation, land use, and other data
to automate the development of hydrologic models.
Once boundaries have been created, geometric attributes such as area, slope and runoff distances can
be computed automatically. A topological tree representation of the watershed is created, and all data
necessary to define hydrologic model can be entered by selecting basins and outlet points. All of the
former models (HEC-1, TR-55, TR-20, Rational, and NFF) are still supported with version 7.1, with
the additions of a complete HMS (the replacement to HEC-1) interface. Many display options are
provided to aid in modeling and understanding the drainage characteristics of terrain surfaces.
WMS is organized into eight modules; four of which was used in this research which are Map
Module to create data layers, Drainage and Terrain Modules to delineate catchment area by using
digital elevation model and calculate of hydrological parameters, and Hydrologic Module to
calculate the peak flow through using the Hydrologic Engineering Center (HEC1) Model. It was
used to delineate the catchment area of the study area both topographical maps that scale 1:100000
and Digital Elevation Model (DEM) which was downloaded from the internet.
4.3.2 Soil Conservation Service (SCS) Based application of WMS
The SCS curve number method assumes that for any storm rainfall, there will be an initial loss Ia,
before any runoff occurs. There will also be an increasing proportional runoff from any subsequent
rainfall as the soil water storage capacity is filled, and infiltration capacity decreases, with
continuation of rainfall. Thus the volume of runoff Q depends on the volume of rainfall P, and the
volume of the storage within the soil available for retention of rainfall. The actual retention during
any storm, F, is the difference of volumes of rainfall and runoff.
This may be expressed as: F/S = Q/ (P-Ia) (1)
9
Where S is the potential maximum retention for any soil.
The actual retention when initial abstraction is considered is:
F = (P-Ia) – Q (2)
When the two equations above are combined:
((P-Ia) - Q) / S = Q / (P – Ia) (3)
Q = (P – Ia) ^ 2 / ((P – Ia) + S) (4)
The initial abstraction is a function of land use, the agriculture practice which affects interception,
and also the infiltration, depression and antecedent moisture state of the catchment. An empirical
relationship is proposed by the SCS where Ia is estimated from the maximum water storage potential
of the soil of the soil by:
Ia = 0.2 * S (5)
Substituting the above value of Ia in equation (4)
Q = (P – 0.2*s) ^2 / (P + 0.8 S) (6)
Estimation of the soil storage potential for any catchment i.e. the value for S is accomplished through
the series of empirical curve numbers, i.e. CN where the storage is:
S = ((1000 / CN) – 10)) * 25.4 (7)
CN is an empirical function of all the factors affecting initial losses and runoff volume, including
surface physical characteristics of the catchment area, land use, and antecedent rainfall conditions.
4.4 FlowMaster Program Application
4.4.1 Description of the Program
FlowMaster is an easy-to-use program that helps civil engineers with the hydraulics design and
analysis of pipes, ditches, open channels, and more. it computes flows and pressures based on wellknown formulas such as Darcy-Weisbach (Colebrook-White), Hazen-Williams, Kutter's, and
Manning's. The program's flexibility allows you to choose an unknown variable, then automatically
compute the solution after you enter known parameters. FlowMaster also calculates rating tables,
and plots curves and cross sections, copy it to the Windows clipboard, save it to a file, or print it on
any standard printer.
4.4.2 Manning Equation Based Application of the FlowMaster
In the case of the absence of any stream-flow observations, flood magnitudes can generally be
estimated after the event from peak flood marks using slope-area method, or, empirical methods can
be used in determining the observed flood using the measured rainfall observations. in this research it
was used the popular Manning’s Formula which derived from The Slope-Area Method that is based
on the cross-sectional area of the Wadi at the crossing, its water surface or bed slope, roughness
characteristics of the Wadi and the historic high flood levels (high flood marks) obtained from field
investigations. These data are applied for the very popular Manning’s Formula to estimate the
observed Floods upon using the FlowMaster software program.
4.5 Stakeholders’ Consultations/Interviews
To implicate the principles of IWRM to realize the objectives of this research a participatory
approach has been taken in consideration during the field work so several consultation sessions have
been conducted with the flood affected people, farmers and residents at AL Mashhad Village which
located downstream of Wadi Doan and also at Al-Hujrain village which located at the mid of the
catchment area of Wadi Doan the purpose of these consultation seasons was to know their points of
view, expectations and concerns regarding, the flood damages, impacts which occurred for their
properties /assets and to know how to mitigate and sustainably manage such floods in the future, The
10
important questions which have been asked to the affected people, farmers and local people as the
following:
• Have you witnessed a significant flood like 2008 flood in your life?
• What are the reasons led to occur such 2008 flood in the Area?
• What are the damages occurred to your property as a result of the 2008 flood?
• What are your suggestions about the suitable solutions to avoid/mitigate the damage/losses of
such floods in the future?
• How to exploit flood waters in such manner lead to realize a sustainable managing of water
resources in the area?
Also consultation sessions have been conducted with the relevant sectors as Seiyun Agricultural
Office, Groundwater and Soil Conservation Project and National Water Resources Authority to
know their points of views/concerns and suggestions concerning how to reduce and mange such
these floods in the future. And also to know the institutional qualified capacity of their sectors to
prepare studies researches and plans to mitigated and manage such flash floods occurred in Wadi
Hadhramout.
4- Results and Discussions
5.1 Rainfall Depths Caused 2008 Flood in The Study Area
The study area was subjected to heavy storms during 22nd, 23th and 24th of October-2008 caused by
the deep depression ARB 02/2008. The data of rainfall storm were collected from the nearby rainfall
stations, as shown previously in section 2.6, Table 2.4, which appears the maximum rainfall intensity
in the most stations was in the day 24th that’s mean the maximum rainfall intensity is the main
reason for flash floods which ranges between 11 mm at Tarim city (Doan station) to 75.5 mm at
Doan area (Doan station) and accordingly the maximum rainfall Intensity which represent Wadi
Doan is 75 mm. whereas 47.6 mm, was the maximum rainfall intensity that occurred on 24th of
October which was recorded by Seiyun-Airport station where Seiyun station is the nearest rainfall
station to Wadi Doan which has long rainfall records.
Unfortunately there is insufficient information about surface flows in the Wadi Hadhramout because
of lack of flow measures stations. In 1989, 10 stations installed by Sir M. MacDonald & Partners in
1985 were lost in one flood season, and only one has been rehabilitated at Tarim in 2002.
5.2 Estimation of Observed Flood
5.2.1 Using of Manning Method Based on FlowMaster Program
The estimation of observed flood is conducted based on two methods, the first method, is using of
Manning Equation method through application of the FlowMaster program based on cross section
data of the Wadi outlet, through entering of the survey data of the cross section in the FlowMaster
program.
This program used the Manning’s Formula, which is Qmax= A×V (m3/s),
Where V= (1/n) R^2/3 X S^1\2 (m/s), V= Velocity (m/s), R= A/P (m), R=Hydraulic Radius (m), A=
Flow Area (m2), P= the Wetted Perimeter (m), S= Wadi slope, n= Roughness Coefficient. The result
of this estimation is shown in the Table 1.1
11
Table 1.1 Estimation Results of Observed Floods
Wadi Name
Water
Elevation
(m)
Roughness
Coefficient
Wadi
Slope
%
Flow Area
(m2)
Observed
Floods (m3/s)
Wadi Doan
5.35
0.0385
0.5
865.01
3850.2
5.2.2 Using of Soil Conservation Service (SCS)
The second method is using SCS Equation through application of the Watershed Modeling System
based on the maximum daily rainfall volume; which caused the flood.
By using of the Digital Elevation Model, the catchment area of Wadi Doan has been divided to seven
sub catchment areas and the October 2008 observed flood hydrographs at the outlets of the sub
catchment areas have been drawn as shown in Figures (1.1), with taken in consideration the
hydrological conditions of each sub catchment area. The flood magnitude of each sub catchment area
is calculated as shown in Table (1.2).
The catchment area has been divided to several sub catchment areas to easily control the flood at
each area through suggestion of construction of storage or / and diversion works.
Figure 1.1Flood Hydrographs of the Sub-Catchment Areas
Table 1.2 Flood Magnitude at each sub Catchment Area
NO
1B
2B
3B
4B
5B
6B
7B
Total B
Coordinates
(m)
X=854603 , Y=1723544
X=856799 , Y=1688055
X=855223 , Y=1669520
X=855692 , Y=1669352
X=857435 , Y=1688049
X=868987 , Y=1676782
X=868274 , Y=1676686
X=854603 , Y=1723544
Sub Catchment Area
(Km2)
795.9
319.26
663.09
385.45
181.02
338.29
487.40
3170.41
12
Flood Magnitude
(m3/s)
713.29
387.82
747.3
430.45
220.34
391.75
528.73
3262.49
5.3 Prediction of Design Peak Flood
The initial abstraction in the Wadi was found to be 11.2 mm. and accordingly this value should be
fulfilled and subtracted from first values of the rainfall storms. The Intensity, Duration and
Frequency (IDF) curves of nearest station (Seiyun station) was used for calculating the effective
rainfall caused the peak floods of 25, 50 and 100 years standard return periods.
The best conformed line has the form of power equation with a very high regression coefficient of R
= 0.811 while the equation is as follows: Q = 1299 * T 0.275
Where Q= the computed flood [m3/s], T=Return period [years]
Frequency analysis were applied to the resulted floods of Wadi Doan that drawn on a logarithmic
distribution, in order to extrapolate them to other frequencies, The results give 3148.06, 3809.13 and
4609.03 m3/s for the frequencies of 25, 50 and 100 years respectively. Whereas the observed
Discharge of the Wadi upon the field survey and using of Flow Master Program is 3850.2 m3/s. The
resulted flood values and the best conform of the line are included in Table (1.3), the observed
discharge conforms to frequency of 50 Years.
Based on the values of the standard frequencies 25, 50 and 100 years which have been calculated at
the outlets of the main and sub catchment areas of Wadi Doan, These magnitudes are useful for
planning, designing and construction of suitable storage and diversions structures in the Wadi.
Because there is insufficient information about the calculation of the design frequencies values and
the discharged magnitude of such floods in the area, previous studies recommended undertaking such
this research.
Table 1.3 Frequency Analysis of Floods at Wadi Doan
T [Years]
Computed
Best Conformed and
Q ([m3/s)
Extension of Q (m3/s)
2
1571.78
5
2022.21
10
2446.86
25
3322.3
3148.06
50
3428.5
3809.13
100
4865.3
4609.03
200
5576.89
500
7175.07
1000
8681.79
2000
10504.91
10000
16353.44
Observed Q
(m3/s)
3850.2
5.4 Floodplain Delineation
Based on the 50 Years storm event the boundary of the floodplain has been drawn as shown in figure
1.2 it is noticed that the 50 year frequency flood can cause erosion for the agricultural areas which
located on the right side of the main stream at downstream where Al Mashhad village might not be
13
exposed for overflow of 50 years storm event. The arable lands which located on the banks of the
main stream can be reclaimed and cultivated and then irrigated from the floods water. In figure 1.3
also shows the boundary of 50 years storm event where the residential places and agricultural areas
located near of the stream might be exposed for 50 and 100 year flood events risks.
Figure 1.2 Floodplain for 50 year flood event at the downstream of Wadi Doan
Figure 1.3 Floodplain for 50 year flood event at the midstream of Wadi Doan
14
The results of this study confirm what was indicated in the previous study prepared by World Bank
that the frequency of the 2008 flood in Wadi Doan is 50 year. However, this study indicate that the
observed maximum discharge magnitude at outlet of Wadi Doan for the 2008 flood event is 3850
m3/s whereas the previous study indicated that the simulated maximum discharge magnitude is 568.8
m3/s so it is noticed that there is significant difference between these two values. And because the
value 3850 m3/s was calculated based on the higher observed flood remarks in the wadi so it is
considered more realistic than the value of 568.8 m3/s which was calculated based on simulated
modeled approach.
5.5 Estimation of Runoff Volume
The estimation of runoff volume ( daily, monthly, and annual) generated at the outlet of catchment
area of Wadi Doan was performed using the SCS method based on Seiyun airport rainfall station, the
results of this analysis is shown as the following:.
 Maximum annual runoff = 164,645,630 m3
 Average annual runoff = 21,958,899 m3
 Minimum annual runoff = 944,049 m3
It is shown that the maximum annual runoff occurred in Wadi Doan in the year 2008 due to of the
heavy rainfall storms, where the average annual runoff has been calculated as an average of 23 years
runoff starting from 1981 to 2002, unfortunately after the year 2002 daily rainfall data is not
available except of the year 2008, the minimum annual runoff in the Wadi was in the year 1987.
5.6 Natural Reasons and Manmade Activities caused the 2008 Flood
Through this research it is resulted that the October 24th 2008 floods occurred due to the natural
reasons; the 2008 deep depression which caused high intensity of rainfall reached 75mm in the Wadi,
large catchment area of 3170 km2 most of it as hilly bared mountains with limited covered
vegetation, tributaries steep slopes, growth of the prosopis (mesquite) trees in the main streams of the
Wadi and lack of protected flood structures as check dams, dikes, bunds and diversion works and
Human made activities; random buildings of residential houses on the banks of the main streams and
sometimes in the streams also.
5.7 Integrated Flood Management within the context of IWRM
From the previous studies and the results of this research, it is noticed that Wadi Hadhramout in
general and tributary Wadi Doan in particular have been yearly experiencing to flash floods that
differ in their frequencies, the floods with low frequencies can be managed through the traditional
diversion structures (as low height barriers, Oqum bunds, drop structures and control structures)
which are existed on the tributaries of Wadi of Hadhramout. However, the floods with the high
frequencies (as 2008 flood) lead to damage of the most of the traditional diversion structures in the
Wadi.
To manage such high frequency flash floods in the Wadi within the context of IWRM and to realize
sustainable water resources for irrigating the agricultural areas and for enhancing groundwater
recharge, several structural measures can be undertaken as rehabilitation of the 2008 flood damaged
traditional diversion structures, construction of new suitable structures at the outlets of sub catchment
areas of the Wadi Doan as incomplete low rocky dams or using oqum systems, and slow down
velocity structures along the sub tributaries of the Wadi to decrease flood velocity, lead to increase
infiltration rates that will enhance groundwater recharge and reduce the flash flooding hazards ( as
leaching of the agricultural lands and fertile soils). Also construction storage dams for recharging
groundwater but not for irrigation is possible cause the geological surface aquifer in the area is
limestone, which characterized by existing fractures that lead to increase recharge processes in the
area, however, selection of the locations of suitable storage dams is required of multi-disciplinary
15
team within the consultation of the area people. Furthermore in the narrow sections of the main
stream of the Wadi where causing blockages can be widened to prevent flood overflow on the
residential or/and agricultural areas.
Nonstructural considerations can be also carried out because plants growing in the Wadi play an
important role in hydrological cycle through transpiration and redistribution of moisture in Wadi-fill
deposits, trees like rophyts and natural pasture can be growing in the upstream areas of the Wadi to
improve affect the vertical (transpiration) and horizontal (pressure) water movement, trees could
reduce soil erosion, thereby contributing to water conservation in Wadi-fill deposits.
Also application of land use and agricultural services programs in the Wadi to determine the areas to
be used as residential areas and to reclamation the bare lands around the main stream of the Wadi
will increase the cultivated areas that absorb the runoff, and reduce the floods. In addition to
practicing agricultural extensions services in the wadi will conserve fertile soils/sedimentations and
enhance the vertical and horizontal agricultural extensions also contribute to reduce the floods
hazards and enhance groundwater recharge from the flood water using in irrigation. Therefore the
agricultural productivity in the area will be increased and accordingly that will lead to improve the
farmer's livelihoods. Furthermore removing of the planting trees and all the obstacles from runoff
streams and canals in the Wadi will contribute in reducing flood overflow on the agricultural lands
or/and residential areas.
Participatory approach shall be used to involve the floods affected people and farmers in the
planning, implementation and managing stages when implementing of the above mentioned
suggested solutions to reduce the floods negative effects and to realize sustainable and integrated
managing of the floods in the Wadi.
Managing such floods in integral approach within the context of IWRM will be more feasible and
lead to reduce the magnitudes of damages and loss in the Wadi because the structural measures will
be implemented based on the values of the maximum flood volumes and frequencies resulted from
this research. Also the nonstructural measures will be carried out with taken in consideration a
participatory approach to involve the community people in the planning, implementation and
managing phases.
5.8 Socio- Economic and Environmental Situation in Wadi Doan
Wadi Doan socio-economic and environmental situation is relatively similar to other Wadis aspects
in Hadhramout as in climatic conditions, agricultural practices, irrigation sources, soil type, crop
pattern, vegetation, community structures, …etc. Wadi Doan are characterized by arid climate; low
rainfall with high evapo-transpiration, water available for irrigation comes from rainfall, seasonal
spate flows running off from mountainous areas which is diverted by traditional simple structures to
transport and distribute water through main and sub canals to cover wide spaces of agricultural
fields, which are located along the two sides of the main stream of Wadi Doan and cultivated by
cereal crops and palm trees.
The resident people in Wadi Doan depend mainly on the agricultural sector as source of their
income. Despite they depend on agriculture, a large number of them are considered poor, the poverty
percentage in Wadi Doan is 0.25 and the number of poor 10,937.
Wadi Doan was damaged of its water diversion structures, lashing of agricultural lands and crops,
uprooting of palm trees and damage of residential buildings where the affected people indicated that
around 100 hundred houses were completely destroyed, and 25 houses partially damaged, 25 Loss to
agricultural possessions, and 150 Loss to Beekeeping properties.
5.9 Interviews and Consultations
During the field study; a group discussions/consultations with the flood affected people, farmers
and residents at AL Mashhad and Al Hujrain Villages have been conducted to know their points
16
o
o
o
o
o
o
o
o
o
o
o
o
o
o
o
of view, expectations and concerns about the flood damages which occurred for their properties
and what are the suitable solutions to avoid such this flood in the future.
The results of discussions/consultations with around 45 interviewees can be outlined as the
following:73% of the interviewees answered that the floods damaged their water diversion structures in the
Wadi, lashing parts of agricultural lands and crops which are located nearby the main stream of
the Wadi, uprooting of palm trees, loss of animals and bees and damaged of the roads whereas
27% of them said that they were not affected of the floods .
53 % of the affected people answered that the flood uprooted their palms, 22 % of them said that
flood lashed a part of their agricultural land with crops, 13% of them said that the flood leached
their bees, 12% of them said that the flood damaged their houses either partially or totally.
To manage the flood water in the Wadi in sustainably manner 71% of the interviewees said the
government shall rehabilitate their traditional diversion structures which are damaged, construct
storage structures along the upstream tributaries to enhance groundwater recharge and diversion
works to divert flood water to their agricultural areas and 29 % of them suggested that
government shall support farmers with agricultural extension services and support them to
reclamation other arable land that will enable them to exploit flood water for irrigation. In
addition to build protection walls from the stone along the two sides of the main stream of the
Wadi especially at AL Mashhad village where the agricultural lands are eroded.
76% of the interviewees said that they haven’t witnessed like the 2008 flood in their lives where
24 % of them answered that they had witnessed like this flood in their lives.
All of them said that the reasons of occurrence of this flood due to of the heavy rainfall which
continued for about three days, large catchment area of the Wadi within bared hilly rocks.
Many of them were economically affected due to loss of their crops, which they rely on as source
of their income.
The interviewees said in Wadi Doan in general around 100 hundred houses were completely
destroyed, and 25 houses partially damaged 25 Loss to agricultural possessions, and 150 Loss to
beekeeping properties.
Environmentally their agricultural soils exposed to erosion, lashing of vegetation especially palm
trees as shown in the photos included in the appendix 3.
Selection the types of the flood protected structures and the locations shall be identified along
within the participation of the area residents.
The local people ensure that they would contribute to maintain the branch canals which deliver
and distribute irrigation water into the agricultural lands with ensuring that irrigation water rights
would be distributed according to the traditions and customs dominated in the area.
Several consultations have been conducted with the relevant sectors in Seiyun as Agriculture
Office, Groundwater and Soil Conservation Project (GSCP) and National Water Resources
Authority (NWRA) branches to know their points of views/concerns and suggestions concerning
how to reduce and mange such these floods in the future. The results of these consultations
outlined as the following:Their branches lack for specialized staff to study such these floods.
They indicated that the branches budgets are limited to construct flood reduce structures.
It is important to construct floods diversion and check structures along the Wadi to reduce the
magnitude of the floods and also to enhance groundwater recharge especially these traditional
structures have been developed and practiced for many centuries in the area.
Due to Wadi Hadhramout lacks of floods related studies, they suggested that the government
shall establish Flood Research Center to be responsible for the studying, prediction and managing
the floods in Wadi Hadhramout and this Center shall be in linkage with various relevant sectors.
They confirmed the importance of promotion of cooperation and coordination among the relevant
sectors concerning flood management in the Wadi.
17
o The flood affected people and the farmers benefited from the floods for irrigation shall be
involved in planning, implementation, maintenance and decision making of any action will be
taken to manage floods and water resources in the Wadi.
5- CONCLUSION AND RECOMMENDATIONS
6.1 Conclusions
 The October 24th 2008 floods occurred due to the natural reasons; the 2008 deep depression,
large hilly catchment area with limited covered vegetation, tributaries steep slopes, growth of the
prosopis (mesquite) trees in the main streams of the Wadi and lack of protected flood structures as
check dams, dikes, bunds and diversion works and Human made activities; random buildings of
residential houses on the banks of the main streams and sometimes in the streams also.
 The 2008 observed flood magnitude at the outlet of Wadi Doan amounted 3850.2 (m3 /s), of
volume 164.65 Million m3.
 The banks at the outlet of the Wadi Doan eroded and widened of 4.0 m of each bank.
 Several agricultural lands and water diversion works were eroded and leached out by the flood.
 The suitable structures which can be constructed to reduce and manage the floods at the outlets of
sub catchment areas of the Wadi Doan are check dams as incomplete low rocky dams or using
oqum systems as well as diversion works.
 Plants growing in the Wadi play an important role in hydrological cycle through transpiration and
redistribution of moisture in Wadi-fill deposits, trees like rophyts can be growing in the upstream
areas of the Wadi to improve affect the vertical (transpiration) and horizontal (pressure) water
movement, in addition, trees could reduce soil erosion, thereby contributing to water conservation
in Wadi-fill deposits.
 Wide arable lands located on the two banks of the main stream of Wadi Doan can be reclaimed
and cultivated and that will contribute to reduce floods peak flow through exploitation of the
floods water for irrigation.
 Estimations of flood peaks based on flood hydrographs are essential to safe design of the water
structures.
 Wadi Doan has occasional high flood potential which may at any times cause loss of human life
and damage to their property and loss of livestock lives. At the same time there is no any early
warning system either in Wadi Doan or Wadi Hadhramout.
 The weak role of community people in managing the floods through their traditional structures
lead to increase the probability of floods risks on their properties.
 There is insufficient information about surface flows in the Wadi Hadhramout in in general and in
the Wadi Doan in Particular because of lack of flow measures and rainfall stations.
6.2 Recommendations
 To reduce and manage the floods at Wadi Doan it is recommended to construct check
dams/diversion works at the outlets of sub catchment areas of the Wadi Doan, and protection
walls and terraces along the agricultural land banks at Al Mashhad Area and stopping farmers of
cultivating the flood streams, activating farmers of cultivating the arable lands which located on
the banks of the main stream of the Wadi with introduction of the agricultural extension services
based on application of land use program.
 Considering the importance of flood prediction in order to reduce flood risks and also for the
purpose of water resources assessment and management, it is recommended that a center of flood
monitoring, prediction and early warning system shall be established.
18
 It is recommended to install a flow gauging station at the outlet of Wadi Doan near AL Mashhad
area at coordinates X=855.277 km , Y=1723.751km, and install rainfall station in the mid
catchment of the Wadi at Al-Hujrain village at coordinates X=861.870 km, Y=1671.000 km.
 Activation of the community role to be involved in flood reduction and management actions
through participation in planning, constructing, operating and maintenance of the different flood
reduced and protected structures.as well as promotion of their traditional customs and rules
through formation of WUGs/WUAs and IC in the Wadi to divert and distribute flood irrigation
water based on equitable manner.
 Carry out more studies about flood prediction, control and management in Wadi Hadhramout in
general and Wadi Doan in particular as to determine the floodplain for 100 year flood event by
using HEC-RAS model.
6- REFERENCES:
• Douben, N., Ratnayake, RMW., 2005, Characteristic data on river floods and flooding; facts
and figures. In Floods, from Defence to Management. Proceedings of the 3rd International
Symposium on Flood Defense, 25–27 May 2005, Nijmegen, the Netherlands, Alphen J. van,
van Beek E, Taal M (eds). Taylor & Francis/Balkema Publishers: Leiden, the Netherlands.
• Noman, A., Arya, D.S., Bhattacharya, B., Yudianto, D., Annor, F.O., Mimi, Z. and Soliman,
M., December, 2007, Early Flood Warning System for Ungauged Basins, Joint Research
Proposal, submitted to Partnership for Water Education and Research.
• World Bank, the United Nations International Strategy for Disaster Reduction, the
International Federation for the Red Crescent and Cross, supported by the Global Facility for
Disaster Risk Reduction, January, 2009, Damage, Losses and needs Assessment October
2008
Tropical
Storm
and
floods,
Hadhramout
and
AlMahra,RepublicofYemen.website:www.gfdrr.org/docs/Yemen_DLNA_Report.pdf.
• Komex International LTD, March 2002, Water Resources Management Studies In the
Hadhramout Region, volume 1, Draft Final Report ,Prepared for: United Nations
Procurement Division (RFPS-63),National Water Resources Authority, Sana’a ,Yemen.
• Ministry of Water and Environment (MWE) , in Joint with UNEP/OCHA Environment Unit,
January 2006, Environmental Emergencies Training and Contingency Planning Workshop
Report, Sana’a, Yemen, Published in Switzerland, March 2006 by the Joint UNEP/OCHA
Environment Unit .www.ochaonline.un.org/OchaLinkClick.aspx?link=ocha&DocId.
• Shamsheir, F., January, 2009, Study of the floods reasons and their damage magnitude in
Hadhramout. Scientific Symposium about study and diagnose floods disaster in Hadhramout,
Seiyun-Tarim, (Arabic version).
• South Sinai Regional Development Programme (SSRDP), Governorate of South Sinai, 2006,
Environmental Impact Assessment for the Flood Protection of the City of Dahab, Egypt ,EIA
Report , Europe Aid/122288/D/SV/EG.
19