Technologies

Water Spreading (typical example from Hashatribab) [Sudan]

Sidud (Local Arabic) - Tarrit (Beja dialect) for earth dams

technologies_1292 - Sudan

Completeness: 78%

1. General information

1.2 Contact details of resource persons and institutions involved in the assessment and documentation of the Technology

Key resource person(s)

SLM specialist:
SLM specialist:
Name of the institution(s) which facilitated the documentation/ evaluation of the Technology (if relevant)
Soil Conservation, Land Use and Water Adminstratio (Soil Conservation, Land Use and Water Adminstratio) - Sudan

1.3 Conditions regarding the use of data documented through WOCAT

The compiler and key resource person(s) accept the conditions regarding the use of data documented through WOCAT:

Yes

1.4 Declaration on sustainability of the described Technology

Is the Technology described here problematic with regard to land degradation, so that it cannot be declared a sustainable land management technology?

No

1.5 Reference to Questionnaire(s) on SLM Approaches (documented using WOCAT)

2. Description of the SLM Technology

2.1 Short description of the Technology

Definition of the Technology:

Water Spreading (or Spate Irrigation system) conducted through the construction of earth dam structures at the khor cross section.

2.2 Detailed description of the Technology

Description:

Water Spreading (or Spate Irrigation) can be done through the construction of an angled bank or weir – with a spillway in case of excess flow – to divert a “khor” (ephemeral stream) and spread it (using spaced contour bunds) for crop production.

Water Spreading from khors or wadis where channelized runoff/ floodwater is diverted onto plains which are then cultivated on residual moisture. An example of a scheme which was constructed in 1999 is located at Hashitribab, some 7 km from Sinkat on the road towards Kassala. This scheme, comprising a stone-pitched earth diversion barrier across a khor (an ephemeral water course), is documented by using among others the WOCAT Questionnaire and WOCAT’s QA. While the diversion is still intact and provides water to the fields about one kilometre downstream (there were young sorghum plants growing at the time of the visit in November 2011) maintenance will be needed.
There was only a very small input of voluntary labour in its original construction (comprising a contribution in terms of stone pitching).

Construction by the Government, using machinery, with little local contribution might explain why voluntary maintenance of the structures has been negligible. Water spreading schemes have gradually expanded in number over the last 20 years in Red Sea State (according to Sayed Dabloub’s personal comment). Currently it was confirmed that there are new sites under planning and construction.

The purposes of diversion dam construction was to divert the main water course to take its way in the crop growing area replacing the old one and being controlled by small diversion dams (terraces to spread water for even water distribution through the original land. These terraces remarkably reduce gully formation.
Most important purpose is to provide water to growing crops in an area which is too dry for rain fed production and where no source for irrigation is available. It secures moisture during the growing season, by allowing more water to penetrate soil and to preserve moisture for a longer period at plant root zone.
The decrease of flood water velocity leads to silt accumulation and other debris materials which increase soil capability in providing moisture, nutrients and maintain soil structure and conservation.

For the earthen/stone-pitched diversion structure with spillway and small haffir alongside machines have been used (mainly loaders provided by the government) which excavated and built the bund. In addition local communities were involved in some aspects of the establishment (mainly stone pitching) supported/subsidized with incentives. The structure/scheme at Hashitribab (close to Sinkat) was built in 1999 (and no maintenance has been done since that time). It helps in watering about 500 feddan (c. 200 hectares) of agricultural area where water is spread by the use of small contour bunds: these were also constructed using subsidies and machines.
Terraces are usually used to control water spreading along the cropped area. Those terraces usually receive the water at low speed velocity. For that reason they are very small in size and volume. Usually they are located in very gentle and uniformed areas. The terraces can be constructed by simple hand tool and tractors accessories. But the prolonged drought makes the maintenance difficult as the dry soil is more susceptible to wind erosion and sand accumulation on both sides of the dam and the bottom of the bund is one of several desertification phenomenon in the region. But the wind-blown sand is one of the most serious one especially in the dry lands of the Red Sea State. Contour survey for land leveling slope identification and location is an important step before implementation.

The study site is located in the arid region of Red Sea State where steep hills from north-south inland mountains are interrupted by arid plains. The population density is low and the population depends on both cropping and livestock with high incidence of poverty. For this reason there should be a clear plan for construction and community extension approach to care about the maintenance of the technology. About 120 families live in Hashitribab area. All the year round they secure their provision by storing food crops in particular sorghum.

2.3 Photos of the Technology

2.5 Country/ region/ locations where the Technology has been applied and which are covered by this assessment

Country:

Sudan

Region/ State/ Province:

Red Sea

Further specification of location:

Sinkat Locality

Specify the spread of the Technology:
  • evenly spread over an area
If precise area is not known, indicate approximate area covered:
  • 1-10 km2

2.6 Date of implementation

If precise year is not known, indicate approximate date:
  • 10-50 years ago

2.7 Introduction of the Technology

Specify how the Technology was introduced:
  • through land users' innovation
Comments (type of project, etc.):

This scheme was built – in 1999 - on the site of a smaller traditional diversion

3. Classification of the SLM Technology

3.1 Main purpose(s) of the Technology

  • improve production
  • reduce, prevent, restore land degradation

3.2 Current land use type(s) where the Technology is applied

Cropland

Cropland

  • Annual cropping
Annual cropping - Specify crops:
  • cereals - sorghum
Number of growing seasons per year:
  • 1
Specify:

Longest growing period in days: 90

Comments:

Major land use problems (compiler’s opinion): Soil vulnerability to erosion due to rainfall irregularity and characterized by drought cycles; in some years rainfall recorded complete absence. Bare and and dried soils are easily affected by erosion agents (wind and water erosion) as these soils are weakly tolerant. Soils in plains are very poor, not renewable and are affected more than soils in seasonable rivers which are renewable with high soil water moisture.
Major land use problems (land users’ perception): Rain fed soils are weak in moisture holding capacity contrast to soils in flush irrigation soils and preferably used for seasonal cultivation by users and producing stable food crops with good productivity besides all underground water for human consumption and livestock through wells at reasonable depths are to be found.
Future (final) land use (after implementation of SLM Technology): Cropland: Ca: Annual cropping

3.3 Has land use changed due to the implementation of the Technology?

Cropland

Cropland

  • Annual cropping

3.4 Water supply

other (e.g. post-flooding):
  • post-flooding

3.5 SLM group to which the Technology belongs

  • cross-slope measure
  • water diversion and drainage

3.6 SLM measures comprising the Technology

structural measures

structural measures

  • S2: Bunds, banks

3.7 Main types of land degradation addressed by the Technology

soil erosion by water

soil erosion by water

  • Wt: loss of topsoil/ surface erosion
  • Wg: gully erosion/ gullying
  • Wo: offsite degradation effects
Comments:

Main causes of degradation: crop management (annual, perennial, tree/shrub) (Clearance of land from resdues to mitigate erosion), overgrazing (Stocking at trees and shrubs continue during the flowering stage preventing seeds production.), industrial activities and mining (To manage mining activities.), change in temperature (Reduced rainfall rate and more affection by wind erosion.), change of seasonal rainfall (More unpredictable and uncertain), Heavy / extreme rainfall (intensity/amounts) (affect in water erosin), droughts (affect passively on the vegetation cover and disintegration of rural families.), poverty / wealth (Not able to conserve resources)
Secondary causes of degradation: soil management (Breaking and blanking soil clods, and leveling and furrowing to increase soil roughness specially at wet seasons to reduce water erodability.), deforestation / removal of natural vegetation (incl. forest fires) (excessive use of tree products), over-exploitation of vegetation for domestic use (Rising population and thus more resource requirements. This is typically is round growing population at urban at centres unlike to people in rural areas except at rainy season where they are gathered), urbanisation and infrastructure development (Sequence to absence of infrastructures and related problems of drought increased rural migration to urban areas.), wind storms / dust storms (Erosion of top soil by wind blown.), floods (unless controlled), inputs and infrastructure: (roads, markets, distribution of water points, other, …) (Blocking water flow in some areas), education, access to knowledge and support services (Low environmental awareness and preparedness.)

3.8 Prevention, reduction, or restoration of land degradation

Specify the goal of the Technology with regard to land degradation:
  • prevent land degradation
  • restore/ rehabilitate severely degraded land

4. Technical specifications, implementation activities, inputs, and costs

4.1 Technical drawing of the Technology

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Author:

Dr. Adil Khidir, Fuculty of Engineering, Kartoum University

4.3 Establishment activities

Activity Timing (season)
1. Excavation of foundation trenches. 1 week
2. Backfilling with heavy soil 1 day
3. Establishment diversion structure 8 weeks
4. Stonepitching by hand 3 weeks
5. Construction of spillway 2 weeks

4.4 Costs and inputs needed for establishment

Specify input Unit Quantity Costs per Unit Total costs per input % of costs borne by land users
Labour labour ha 1.0 57.0 57.0
Equipment machine use ha 1.0 355.0 355.0
Total costs for establishment of the Technology 412.0
Total costs for establishment of the Technology in USD 412.0

4.5 Maintenance/ recurrent activities

Activity Timing/ frequency
1. Tillage before fluding period

4.6 Costs and inputs needed for maintenance/ recurrent activities (per year)

Comments:

For the diversion structure and spillway at time of construction (1999)

4.7 Most important factors affecting the costs

Describe the most determinate factors affecting the costs:

The slope and depth of the wadi/ khor to be diverted

5. Natural and human environment

5.1 Climate

Annual rainfall
  • < 250 mm
  • 251-500 mm
  • 501-750 mm
  • 751-1,000 mm
  • 1,001-1,500 mm
  • 1,501-2,000 mm
  • 2,001-3,000 mm
  • 3,001-4,000 mm
  • > 4,000 mm
Agro-climatic zone
  • arid

Thermal climate class: tropics

5.2 Topography

Slopes on average:
  • flat (0-2%)
  • gentle (3-5%)
  • moderate (6-10%)
  • rolling (11-15%)
  • hilly (16-30%)
  • steep (31-60%)
  • very steep (>60%)
Landforms:
  • plateau/plains
  • ridges
  • mountain slopes
  • hill slopes
  • footslopes
  • valley floors
Altitudinal zone:
  • 0-100 m a.s.l.
  • 101-500 m a.s.l.
  • 501-1,000 m a.s.l.
  • 1,001-1,500 m a.s.l.
  • 1,501-2,000 m a.s.l.
  • 2,001-2,500 m a.s.l.
  • 2,501-3,000 m a.s.l.
  • 3,001-4,000 m a.s.l.
  • > 4,000 m a.s.l.

5.3 Soils

Soil depth on average:
  • very shallow (0-20 cm)
  • shallow (21-50 cm)
  • moderately deep (51-80 cm)
  • deep (81-120 cm)
  • very deep (> 120 cm)
Topsoil organic matter:
  • low (<1%)

5.4 Water availability and quality

Ground water table:

< 5 m

Water quality (untreated):

poor drinking water (treatment required)

5.6 Characteristics of land users applying the Technology

Market orientation of production system:
  • subsistence (self-supply)
Off-farm income:
  • 10-50% of all income
Individuals or groups:
  • individual/ household
Level of mechanization:
  • manual work
Gender:
  • women
  • men
Indicate other relevant characteristics of the land users:

Land users applying the Technology are mainly disadvantaged land users
Population density: < 10 persons/km2
Annual population growth: 2% - 3%
100% of the land users are poor.
Off-farm income specification: Other activities include casual labour and livestock raising

5.7 Average area of land used by land users applying the Technology

  • < 0.5 ha
  • 0.5-1 ha
  • 1-2 ha
  • 2-5 ha
  • 5-15 ha
  • 15-50 ha
  • 50-100 ha
  • 100-500 ha
  • 500-1,000 ha
  • 1,000-10,000 ha
  • > 10,000 ha
Is this considered small-, medium- or large-scale (referring to local context)?
  • small-scale

5.8 Land ownership, land use rights, and water use rights

Land ownership:
  • communal/ village
  • individual, titled
Land use rights:
  • communal (organized)
  • individual

5.9 Access to services and infrastructure

health:
  • poor
  • moderate
  • good
education:
  • poor
  • moderate
  • good
technical assistance:
  • poor
  • moderate
  • good
employment (e.g. off-farm):
  • poor
  • moderate
  • good
markets:
  • poor
  • moderate
  • good
energy:
  • poor
  • moderate
  • good
roads and transport:
  • poor
  • moderate
  • good
drinking water and sanitation:
  • poor
  • moderate
  • good

6. Impacts and concluding statements

6.1 On-site impacts the Technology has shown

Socio-economic impacts

Production

crop production

decreased
increased
Comments/ specify:

Relative to nothing otherwise

fodder production

decreased
increased

risk of production failure

increased
decreased

production area

decreased
increased
Water availability and quality

drinking water availability

decreased
increased
Income and costs

farm income

decreased
increased

diversity of income sources

decreased
increased

Socio-cultural impacts

food security/ self-sufficiency

reduced
improved

cultural opportunities

reduced
improved

recreational opportunities

reduced
improved

community institutions

weakened
strengthened

competition with natural ecosystem

increased
decreased
Comments/ specify:

Floodwaters diverted will not reach original destination and those former beneficiaries

contribution to human well-being

decreased
increased
Comments/ specify:

Due to more reliable production despite low and variable rainfall

Ecological impacts

Water cycle/ runoff

water quantity

decreased
increased

water quality

decreased
increased

harvesting/ collection of water

reduced
improved

surface runoff

increased
decreased

evaporation

increased
decreased
Soil

soil moisture

decreased
increased

soil cover

reduced
improved

soil organic matter/ below ground C

decreased
increased
Other ecological impacts

competition with natural ecosystem

increased
decreased
Comments/ specify:

Floodwaters diverted will not reach original destination

6.2 Off-site impacts the Technology has shown

water availability

decreased
increased

downstream flooding

increased
reduced

6.3 Exposure and sensitivity of the Technology to gradual climate change and climate-related extremes/ disasters (as perceived by land users)

Gradual climate change

Gradual climate change
Season increase or decrease How does the Technology cope with it?
annual temperature increase well

Climate-related extremes (disasters)

Hydrological disasters
How does the Technology cope with it?
general (river) flood well
Comments:

Construction of water spreading devices serves to preserve water, reduce the waste, increase soil moisture capacity and raise soil fertility (silt accumulation)

6.4 Cost-benefit analysis

How do the benefits compare with the establishment costs (from land users’ perspective)?
Short-term returns:

slightly positive

Long-term returns:

positive

Comments:

no maintenance carried out so not applicable here

6.5 Adoption of the Technology

  • > 50%
Comments:

75% of land user families have adopted the Technology with external material support
102 land user families have adopted the Technology with external material support, scheme construction subsidised by Government
15% of land user families have adopted the Technology without any external material support
18 land user families have adopted the Technology without any external material support
There is no trend towards spontaneous adoption of the Technology. People cannot construct khor/ wadi diversion barriers themselves by hand

6.7 Strengths/ advantages/ opportunities of the Technology

Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view
Useful and important in the area where floodwater harvesting/ spate irrigation is the only option for crop production. No rain fed irrigation system on the Red Sea State unlike to other Sudan.

6.8 Weaknesses/ disadvantages/ risks of the Technology and ways of overcoming them

Weaknesses/ disadvantages/ risks in the land user’s view How can they be overcome?
SLM not falls under the community responsibility. They believe SLM is completely Gos role. Land users awareness and involvement
They don’t think that community plays a role in the ongoing soil and vegetation degradation Rotational grazing and seed broadcasting
They also say no regular concern by the government is given in relation to land reclamation A location of budget and equipment to reclaim land and natural vegetation conservation.
They confirm that the physical conditions played a great role in land degradation e.g. drought aridity and high temperatures . To ensure water harvesting and without waste.
Weaknesses/ disadvantages/ risks in the compiler’s or other key resource person’s view How can they be overcome?
High cost (needs machinery to move earth) More support from Government and outside
Not enough trained personnel More up-grading skills are required
Very little data available (apart from construction details) Better system of monitoring and evaluation
Low technical capacity of the community Capacity building and training

7. References and links

7.1 Methods/ sources of information

  • field visits, field surveys
  • interviews with land users

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