This is an outdated, inactive version of this case. Go to the current version.
Technologies
Inactive

Trees in the riparian area as a protective and aesthetic advantage at Naro Moru River [Kenya]

technologies_1580 - Kenya

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:
land user:

Wanjiru Cecilia

Kenya

Name of the institution(s) which facilitated the documentation/ evaluation of the Technology (if relevant)
CDE Centre for Development and Environment (CDE Centre for Development and Environment) - Switzerland

1.3 Conditions regarding the use of data documented through WOCAT

When were the data compiled (in the field)?

14/11/2012

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

Yes

2. Description of the SLM Technology

2.1 Short description of the Technology

Definition of the Technology:

Trees are planted along the riparian zone to stabilize the riverbank and to prevent degradation. The wood can be used to establish a building or to generate income on the market.

2.2 Detailed description of the Technology

Description:

At the foot slopes of Mt. Kenya a farmer has developed a technology to protect the own land plot from riverbank erosion. The technology consists of three main measures: A wall along the riverbed, trees that are aligned on the wall as well as beside it and Napier grass wildly scattered between the trees. The wall was built on a highly exposed spot of the riverbank. Trees along and beside the wall ensure its stability. The combination of the two measures results in an effective protection of the riverbank in terms of erosion. Side effects of the technology are higher runoff during the dry season, better water quality due to less erosion and an improved riparian habitat for animals and plants.

Purpose of the Technology: For a small scale farmer, planting of trees can have advantages in an economic, an ecologic and an aesthetic point of view. The trees stabilize the soil, allow the riparian vegetation to establish, and prevent major damages through flooding. Furthermore, there are several advantages of an intact riparian zone, such as enhanced biodiversity, increased water quality as well as retention of agrochemicals. The trees also work as a kind of bank account, since the prices for wood are quite high. Trees can be cut and sold from time to time to generate an income that can be used for further investments like local entrepreneurship or building houses for family members. Last but not least, the farmer emphasized the beautiful appearance of the trees including the relatively cool micro- climate the trees are able to provide during the hot months of the dry period.

Establishment / maintenance activities and inputs: The trees were planted during the rainy season. Braches are pruned regularly and provide mulch material as well as fire wood. When trees are reaching maturity they will selectively be cut and replanted. The Napier grass is cut regularly for fodder to be feed to animals. At this particular time, there is a regular hay yield (weed). Seedlings for trees and the grasses are produced on site. Occasional pruning ensures fuel wood supply.

Natural / human environment: The plot is situated at the western side of Mt. Kenya in its foot zone, a moderate hilly region. Actually, the foot zone is a transition area between the humid mountain forest above elevations of 2500 m.a.s.l and the semi-arid savannah zone below 2000 m a.s.l. Although the region is located in the rain shadow of Mt. Kenya, there is just enough precipitation (740mm) to sustain rain fed agriculture and the farmers even benefit from a water project. During the last decades, the region has experienced a still continuing population growth which increases population pressure in the area. The good accessibility and the moderate tourism allow even off-farm income-generation.

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:

Kenya

Region/ State/ Province:

Kenya/Central Province

Further specification of location:

Naro Moru

2.6 Date of implementation

If precise year is not known, indicate approximate date:
  • less than 10 years ago (recently)

2.7 Introduction of the Technology

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

The land user has enough space to afforest along the riparian. The main goals are to stabilise the riparian soil and to produce wood for use in the future.

3. Classification of the SLM Technology

3.1 Main purpose(s) of the Technology

  • reduce, prevent, restore land degradation

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

Cropland

Cropland

  • Annual cropping
Forest/ woodlands

Forest/ woodlands

Products and services:
  • Timber
  • Fuelwood
  • Nature conservation/ protection
  • Recreation/ tourism
Comments:

Major land use problems (compiler’s opinion): Surface water pollution and riverbank degradation as well as a diminished habitat of riparian flora and fauna.

Major land use problems (land users’ perception): An unstable riparian zone being eroded by the river and unattractive aesthetics.

Problems / comments regarding forest use: The purpose of the forest is mainly in a protective way. Later on, as soon as the trees are large enough, selective felling for construction is planned.

Forest products and services: timber, fuelwood, nature conservation / protection, recreation / tourism

Future (final) land use (after implementation of SLM Technology): Forests / woodlands: Fp: Plantations, afforestations

If land use has changed due to the implementation of the Technology, indicate land use before implementation of the Technology:

Cropland: Ca: Annual cropping

3.3 Further information about land use

Number of growing seasons per year:
  • 2
Specify:

Longest growing period in days: 90 Longest growing period from month to month: april to may Second longest growing period in days: 90 Second longest growing period from month to month: october to november

3.4 SLM group to which the Technology belongs

  • natural and semi-natural forest management
  • improved ground/ vegetation cover

3.5 Spread of the Technology

Specify the spread of the Technology:
  • evenly spread over an area
If the Technology is evenly spread over an area, indicate approximate area covered:
  • < 0.1 km2 (10 ha)

3.6 SLM measures comprising the Technology

vegetative measures

vegetative measures

  • V1: Tree and shrub cover
structural measures

structural measures

  • S6: Walls, barriers, palisades, fences
Comments:

Main measures: vegetative measures

Secondary measures: structural measures

Type of vegetative measures: aligned: -linear, scattered / dispersed

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
  • Wr: riverbank erosion
biological degradation

biological degradation

  • Bc: reduction of vegetation cover
  • Bs: quality and species composition/ diversity decline
water degradation

water degradation

  • Hp: decline of surface water quality
  • Hw: reduction of the buffering capacity of wetland areas
Comments:

Main type of degradation addressed: Wr: riverbank erosion, Bs: quality and species composition /diversity decline, Hp: decline of surface water quality

Secondary types of degradation addressed: Wt: loss of topsoil / surface erosion, Bc: reduction of vegetation cover, Hw: reduction of the buffering capacity of wetland areas

Main causes of degradation: deforestation / removal of natural vegetation (incl. forest fires), over-exploitation of vegetation for domestic use, population pressure, education, access to knowledge and support services

Secondary causes of degradation: floods

3.8 Prevention, reduction, or restoration of land degradation

Specify the goal of the Technology with regard to land degradation:
  • prevent land degradation
  • reduce land degradation
Comments:

Secondary goals: mitigation / reduction of land degradation

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

4.1 Technical drawing of the Technology

Author:

Manuel Fischer

4.2 Technical specifications/ explanations of technical drawing

Indigenous trees, a wall and Napier grass are installed between the agricultural land and the river. The wall prevents erosion at a very endangered spot. The trees and the grass provide fodder and wood.

Location: Naro Moru. Nyeri / Central Province

Technical knowledge required for field staff / advisors: moderate

Technical knowledge required for land users: low

Main technical functions: increase of infiltration, improvement of water quality, buffering / filtering water, sediment retention / trapping, sediment harvesting, stabilization of riverbank by trees and grasses

Secondary technical functions: stabilisation of soil (eg by tree roots against land slides)

Aligned: -linear
Vegetative material: T : trees / shrubs
Number of plants per (ha): 200
Vertical interval between rows / strips / blocks (m): 0
Spacing between rows / strips / blocks (m): 1
Vertical interval within rows / strips / blocks (m): 1.5
Width within rows / strips / blocks (m): 2

Scattered / dispersed
Vegetative material: G : grass
Number of plants per (ha): 800

Trees/ shrubs species: Cypress, Grevillea, indigenous trees

Fruit trees / shrubs species: Napier grass

Wall/ barrier
Height of bunds/banks/others (m): 0.5m
Width of bunds/banks/others (m): 2m
Length of bunds/banks/others (m): 10m

4.3 General information regarding the calculation of inputs and costs

Specify how costs and inputs were calculated:
  • per Technology unit
Specify currency used for cost calculations:
  • US Dollars
Indicate average wage cost of hired labour per day:

2.70

4.4 Establishment activities

Activity Type of measure Timing
1. Setting up a tree nursery Vegetative
2. Planting seedlings Vegetative during rainy season
3. Establishment of wall Structural

4.5 Costs and inputs needed for establishment

Specify input Unit Quantity Costs per Unit Total costs per input % of costs borne by land users
Labour Setting up a tree nursery Persons/day 5.0 3.3333 16.67 100.0
Labour Planting seedlings Persons/day 25.0 3.3333 83.33 100.0
Labour Establishment of wall Persons/day 5.0 3.3333 16.67 100.0
Total costs for establishment of the Technology 116.67

4.6 Maintenance/ recurrent activities

Activity Type of measure Timing/ frequency
1. Replanting trees that dried up Vegetative
2. Cutting the Napier grass and pruning trees Vegetative during the rainy seasons = 4 months a year. 3 times a month

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

Specify input Unit Quantity Costs per Unit Total costs per input % of costs borne by land users
Labour Replanting trees Persons/day 3.0 3.3333 10.0 100.0
Labour Cutting the Napier grass and pruning trees Persons/day 12.0 3.33333 40.0 100.0
Total costs for maintenance of the Technology 50.0
Comments:

Establishment has been carried out over a time period of 5 years. Considering this time frame, the establishment costs are smaller than the maintenance costs.
The costs per hectare were calculated for a riparian area with the length of 100 m and a width of 10 m, since hectares are difficult to apply in a riparian context. The determining factor for the costs is labour. In this case, the labour costs are quite high because the seedlings were produced in the own nursery. This explains the high labour costs. Some of the seedlings had to be replanted, because they dried up. The required equipment like a spade is available on nearly every farm or can be borrowed from neighbours and is thus not added to the costs.

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
Indicate the name of the reference meteorological station considered:

NS-Daten Eliza

Agro-climatic zone
  • sub-humid

Thermal climate class: subtropics. source: http://en.climate-data.org/location/103473/

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.
Comments and further specifications on topography:

Altitudinal zone: 2020

Slopes on average: Land plot has a slope between 5% and 9%

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:
  • medium (1-3%)
If available, attach full soil description or specify the available information, e.g. soil type, soil PH/ acidity, Cation Exchange Capacity, nitrogen, salinity etc.

Soil texture: mixture, because it is not red

Soil fertility is high

Soil drainage / infiltration is good

Soil water storage capacity very low - low

5.4 Water availability and quality

Ground water table:

< 5 m

Availability of surface water:

good

Water quality (untreated):

good drinking water

Comments and further specifications on water quality and quantity:

Ground water table: <5 mjust along the river, deeper ground water level 50-100m

Water quality (untreated): From a water project

5.5 Biodiversity

Species diversity:
  • high
Comments and further specifications on biodiversity:

Species diversity: Also medium

5.6 Characteristics of land users applying the Technology

Market orientation of production system:
  • subsistence (self-supply)
  • mixed (subsistence/ commercial
Off-farm income:
  • less than 10% of all income
Relative level of wealth:
  • average
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 common / average land users

Difference in the involvement of women and men: A clan uses the land commonly. Besides the base family (mother, father, son), the grandmother and an uncle use parts of the land. All of them apply the protective technologies in the riparian.

Population density: 200-500 persons/km2

5.7 Average area of land owned or leased 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
Comments:

Average area of land owned or leased by land users applying the Technology: < 0.5 ha for Riparian forest.

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

Land ownership:
  • individual, not titled
Land use rights:
  • individual
Water use rights:
  • communal (organized)
Comments:

Mostly small scale farmers are using the land.

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
roads and transport:
  • poor
  • moderate
  • good
drinking water and sanitation:
  • poor
  • moderate
  • good
financial services:
  • 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

fodder production

decreased
increased
Comments/ specify:

Napier grass yield has increased

wood production

decreased
increased
Comments/ specify:

Before, there was only little wood production

Socio-cultural impacts

SLM/ land degradation knowledge

reduced
improved

Aesthetics

decreased
improved

Ecological impacts

Water cycle/ runoff

surface runoff

increased
decreased

excess water drainage

reduced
improved
Soil

soil cover

reduced
improved

soil loss

increased
decreased
Biodiversity: vegetation, animals

beneficial species

decreased
increased
Climate and disaster risk reduction

flood impacts

increased
decreased
Other ecological impacts

Riverbank erosion

increased
decreased

6.2 Off-site impacts the Technology has shown

reliable and stable stream flows in dry season

reduced
increased

downstream siltation

increased
decreased

groundwater/ river pollution

increased
reduced

damage on public/ private infrastructure

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 Type of climatic change/ extreme How does the Technology cope with it?
annual temperature increase well

Climate-related extremes (disasters)

Meteorological disasters
How does the Technology cope with it?
local rainstorm well
local windstorm well
Climatological disasters
How does the Technology cope with it?
drought well
Hydrological disasters
How does the Technology cope with it?
general (river) flood well

Other climate-related consequences

Other climate-related consequences
How does the Technology cope with it?
reduced growing period well

6.4 Cost-benefit analysis

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

very negative

Long-term returns:

very positive

How do the benefits compare with the maintenance/ recurrent costs (from land users' perspective)?
Short-term returns:

negative

Long-term returns:

very positive

6.5 Adoption of the Technology

  • single cases/ experimental
If available, quantify (no. of households and/ or area covered):

1 household

Of all those who have adopted the Technology, how many have did so spontaneously, i.e. without receiving any material incentives/ payments?
  • 90-100%
Comments:

Comments on acceptance with external material support: The WRUA has been distributing seedlings among the riparian farmers. Quantification is not possible.

100% of land user families have adopted the Technology without any external material support

6.7 Strengths/ advantages/ opportunities of the Technology

Strengths/ advantages/ opportunities in the land user’s view
There is a recreational aspect of the riparian zone. Especially during hot days the farmer is enjoying the slightly colder temperatures because of the canopy and the cooling stream. The aesthetic aspects of the riparian are also enhanced.

How can they be sustained / enhanced? If the canopy of the riparian is maintained, it can serve still as recreation area and convince with beautiful looks.
Long term benefits in terms of wood and timber provided by the trees.

How can they be sustained / enhanced? If trees are not chopped too early, they will have a good price on the market.
The maintenance of the riparian is not tiring and still gives a good harvest.

How can they be sustained / enhanced? Benefits can be sustained by continuing the management practices.
Diversification: Formerly, there was maize at the river, but it died due to cold temperatures. Forests do not die due to frost.

How can they be sustained / enhanced? Every plant has its special needs that should be kept in mind.
Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view
Wood production through selective felling is sustainable.

How can they be sustained / enhanced? No widespread felling of trees, only selective intervention.
Fodder production enables the keeping of cattle.

How can they be sustained / enhanced? Before dry periods, some fodder should be stored to ensure fodder supplies.

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?
There is less crop yield, because an area of the plot was formerly used for maize production and now it is part of the riparian. The productive and protective benefits of the riparian overcome decreased size of the agricultural plot.

Links and modules

Expand all Collapse all

Modules