erosion control tajikistan2013

8/12/2019 Erosion Control Tajikistan2013

1/43

Natural ResourceManagement

Hand book

Improving preparedness and response abilities to natural disasters

in Central Financed by The Humanitarian Aid and Civil Protection

Department of the European Commission (ECHO).

Soil Bio-engineering

techniques for Slope

protection and Stabilization


2/43

Natural Resource Management

Hand book

Soil Bio-engineering techniques for Slope protectionand Stabilization

Published 2013 by Cesvi, Kujand, Tajikistan

Production team

Giuseppe Bonati (Editor Supervisor)

Irene Marongiu (Editor)

Irene Marongiu (Layout and design)

Cover picture:

Tommaso Cencetti

Annexes to this publication

Soil Bio-engineering Techniques for slope protection and stabilization: 6 leaflets with

description, function and construction guidelines. Editor: Irene Marongiu

Leaflet number 1: Live Palisades; Leaflet number 2: Brush Layering; Leaflet number 3:

Contour Line Fascines; Leaflet number 4: Drainage Fascine; Leaflet number 5: Live

Wattling; Leaflet number 6: Vegetated Gabions Gravity Retaining Wall.

Note

This publication may be reproduced in whole or in part and in any form for educational

or non-profit purposes provided acknowledgement of the source is made. For furtherdissemination you can contact Cesvi [email protected].
mailto:[email protected]:[email protected]:[email protected]:[email protected]


3/43

Natural Resource Management 3

Table of contents

CHAPTER 1 EROSION CONTROL AND SLOPE PROTECTIONERROR! BOOKMARK NOT DEFIN

SOIL EROSION........................................................................................................... 6

SLOPE PROTECTION AND STABILIZATION........................................................................... 6

Nonliving approaches (Civil engineering techniques) ......................................................... 7

Living approach (Bioengineering and Bio technical techniques) ........................................ 7

Categories of techniques and evolution over the time ...................................................... 8

CHAPTER 2 PLANT FUNCTION.................................................................................... 11

MAIN FUNCTION OF PLANT..................................................................................... 12Habitat and biodiversity .................................................................................................... 12

Positive Influence on soil structure ................................................................................... 12

Plant regulation of water balance and reduction of surface erosion ............................... 13

ENGINEERING FUNCTION OF VEGETATION-TECHNICAL CAPACITY..................................... 16

Drain Function - application .............................................................................................. 16

Armour Function: - application ........................................................................................ 17

Catch Function - application ............................................................................................. 18

Support Function - application .......................................................................................... 18

Reinforce Function - application ....................................................................................... 18

Anchor Function - application ........................................................................................... 19

HOW TO CHOOSE THE RIGHT SPECIES ......................................................................... 20

Autochthonous Material ................................................................................................... 20

Biological Properties ......................................................................................................... 20

Stress Resistance: .............................................................................................................. 21

Nitrogen fixation ............................................................................................................... 22

Root development ............................................................................................................ 22

CHAPTER 3 DESIGN CONSIDERATION AND TECHNIQUES................................ 25

CONSIDERATION .................................................................................................. 26

Topography and exposure ................................................................................................ 26

Geology and soils .............................................................................................................. 26

Hydrology .......................................................................................................................... 27

Design considerations ....................................................................................................... 27


4/43

4 Soil Bio-engineering for Slope protection and Stabilization

HOW TO PREPARE CUTTING FOR SOIL-BIO-ENGINEERING ................................................ 28

Best planting seasons ........................................................................................................ 28

Cutting preparation ........................................................................................................... 28

Storage .............................................................................................................................. 29

Layering ............................................................................................................................. 29

SOIL BIO-ENGINEERING TECHNIQUES DESCRIPTION...................................................... 31

Check dams ....................................................................................................................... 31

PalisadeLeaflet number1 ............................................................................................... 33

Brush layering Leaflet number 2.............................................................. 33

Fascines ............................................................................................................................. 34

Contour line fascinesLeaflet number 3........................................................................... 34

Drainage with fascines - Leaflet number 4........................................................................ 35

WattlingLeaflet number 5.............................................................................................. 35

GabionsLeaflet number 6.............................................................................................. 36

Riprap ................................................................................................................................ 39

Pole or Live stake planting ................................................................................................ 39

Trees and cutting protection ............................................................................................. 41

The best time to plant a tr ee is twenty years ago

The second best time is NOW!


5/43

Chapter 1:Erosion control and Slope

Stabilization

SOIL EROSION

What is Soil Erosion? Its a displace of soil by water and wind. Its

water the first erosion agent. There are different level of soil

erosion: sheet erosion and rill erosion. Rill erosion can be easily

fixed. Without control rill erosion can develop to the more severe

gully erosion. SLOPE PROTECTION AND STABILIZATION

The protection and stabilization of slope area con be reach by

applying difference between Nonliving approaches (Civil

engineering techniques) and Living approach (Bioengineering and

Bio technical techniques).Categories of Soil-bioengineering

techniques and evolution of the intervention over the time.


6/43


Soil Erosion

Soil is the most basic resource, providing the medium for plant growth and water

retention.

Soil erosion is defined as the displacement of soil material by erosive agents such as

water and wind. The erosion process consists of detachment of individual soilparticles from land's surface of one place, their transport to another place by erosive

agents such as running water and wind, and finally their deposition when sufficient

energy is no longer available to transport them further1.Water is the first soil erosion

agent, erosion occurs whenever water meets land with enough power to move soil2.

Run-off (figure 5), which is also called surface flow or overland flow, is the rain

water that, instead of infiltrate in the soil remains on the soil surface. As runoff

water moves down a slope, it increases in velocity and increases the potential for

erosion. Sheet erosion3occurs when the run-off move in a thin surface flow along

the ground, it transports detached soil particles and removes more or less uniformthin layer of soil from the smooth and uniform sloping land surface. Sheet erosion

removes only the top layer. In fact, run-off seldom occurs as sheet flow because land

surface is almost always irregular. Irregularities of surface force the flowing water to

accumulate in depressions and result in concentrated water flow that remove soil

particles from small well-defined channels, forming so called rills. Rills are small

enough (


7/43

Chapter 1Erosion control and slope protection 7

Figure 1 Civil engineering: toe wall.

Reducing erosion is a critical first step to the conservation of the productive capacity

of the land and of the safety of the communities. This publication deal with slope

protection and stabilization

The reduction of the downward movement of slope material can be reach by

applying different approaches: Nonliving approaches (Civil engineering techniques)

Living approach

Nonliving approaches (Civil engineering techniques)

This approach uses rigid

constructions, such as surface

armouring, gravity retaining walls,

rock buttresses. Combining

nonliving structures with vegetation

it is possible to create vegetated

structures (e.g.: low walls or

revetments at the foot of a slope

with plant on the interposed

benches figure 1). In this case

vegetation enhances the structures

and helps to reduce the surface

erosion but usually does not provide any major reinforcement benefits. Vegetated

structure, compared with traditional civil engineering techniques, increases the

ecological and aesthetically pleasing integration into the landscape. Vegetated

gabions (gabion with insert cutting of rooted plants - leaflets number 6) are soil-

bioengineering structure because the plants became, over time, the major structural

component.

Living approach (Bioengineering and Bio technical techniques)

The living approach is based on Soil bio-engineering techniques (Soil B.E.).

Soil Bioengineering uses

combinations of live vegetation and

structural practices: plant are seen

from functional point of view, as an

effective living construction

material and used to create a

protective structure. The live

material can be use alone or

combined with locally found

materials (such as rocks, soil, etc)

and/or technical building materials

(net, iron rod, concrete, etc). Figure 2 : Stri ct sensebio-engineering techniquesonly plants are used as structural component.


8/43


It is the use of plants that characterize the Soil bio-engineering!

The aims of Soil B.E. are mainly four:

Technical and functional,

Economic: they are competitive and alternative structures to traditional civil

engineering structures (e.g.: cement retain walls replaced by vegetated gabionswall).

Naturalistic: re-establishment or initiation of natural ecosystems using native

species;

Landscaping;

It merge mechanical, biological, and ecological concept to produce living,

functioning systems for stabilization, consolidation, erosion prevention, sediment

control and renaturization4of hill slopes, stream banks and lakeshores.

Categories of techniques and evolution over the time

In soil bioengineering systems, the living material may play the major structural

roles immediately or may become the major structural component over the time.

Soil bio-engineering can be divided, for didactic reason, into trees categories:

Vegetative plantings;

Bio-engineering in the str ict sense

5

; Bio Technical Techniques

Vegetative plantingsare conventional plantings of grasses, forbs, shrubs in order to

prevent surface erosion. The living material is not used with structural meaning. If

seed or cuttings are used, the erosion prevention function is carry out only once the

vegetation is established.

4Definition of Renaturization:The retransformation of a landscape modified by human intervention

into a state close to nature. Federal Office for Water Management.5Schiechtl, H.M. 1980. Bioengineering for land reclamation and conservation. University of Alberta

Press, Alberta.

ATTENTION!Remember that vegetation cannot perform its engineering function in its initial

stage.

Soil bioengineering has unique requirements and is not appropriate for all sites

and situations.

Soil bioengineering interventions are not the solution for all slope failure and

surface erosion problems. In certain cases, a conventional vegetative treatment

(e.g., grass seeding and hydro mulching) works satisfactorily. In other cases, the

more appropriate and most effective solution is a structural retaining system alone

or in combination with soil bioengineering.

Soil B.E. is sometimes useful to repair and stabilize shallow slope failures but it isalways recommended to consult an engineer or geotechnical engineer before

attempting to repair a deep slope failures.


9/43


Maintaining and restoring vegetative cover is an effective means of reducing

erosion.

Strict senseBio-Engineering, as vegetative planting, uses live materials only as

plants or part of plants (seeds, seedlings, cuttings, branches, pieces of natural stand,

natural turf or sod slabs, etc.). The plant materials itself provide both the vegetative

and structural components of the design.

Live staking, brush layers, wattling, live palisades, live contour line , fascines and

live gully repair use cutting or branch parts as initial and primary soil reinforcing

and stabilizing material, absolving from the beginning the functions of horizontal

drains, barriers to earth movement, and hydraulic pumps6. These live materials

placed in the ground during the growing season develop roots and sprouts foliage.

The resulting vegetation becomes a major structural component of the

bioengineering system and the structure grows stronger with time (seefigure 3).

Bio-Technical Techniques use living materials which are combined or integrated

with non living or structural materials. In this category of interventions vegetative

and structural components work together in mutually reinforcing and has

complimentary roles7.

Live cribwalls8, vegetated gabions (leaflets number 6), vegetated rock walls are

techniques that use porous structures with openings through which vegetative

material (cutting, seedling or seeds) are inserted and established. The inert structural

elements provide immediate resistance to sliding, erosion, and wash out :as

vegetation becomes established, roots invade and permeate the slope, binding it

together into a unified, coherent mass9.Over time, the structural elements undergo to

a progressive loss of strength (decomposition of wood, breaking of wire mesh10,

etc), at the same time diminishes the importance of the no-living elements because

the vegetation increases in strength and functionality.

Once vegetation is well established on a soil bioengineering project, usually within

one growing season, it generally becomes self-repairing by regeneration and growth

and requires little maintenance.

6Biotechnical Stabilization Of Steepened Slopes, Donald H. Gray and Robbin B. Sotir

7Biotechnical Slope Protection and Erosion Control, Gray D.H. and Leiser A.T., New York, 1982.

8A live cribwall consists of a hollow, box-like interlocking arrangement of timber members. The

structure is filled with suitable backfill material and layers of live branch cuttings which root inside

the crib structure and extend into the slope. 9Soil Bioengineering for Upland Slope Protection and Erosion Reduction, Engineering Field

Handbook, October 1992, United States Department of Agriculture Natural Resources Conservation

Service.10

The life expectancy of gabions, for example, depends on the lifespan of the wire. The structure

will fail when the wire fails. PVC-coated galvanized gabions have been estimated to survive for 60

years. Some gabion manufacturers guarantee a structural consistency of 50 years (Wikipedia,

February 2013).


10/43


However, a newly installed soil bioengineering project will require careful periodic

inspections until it is established. Established vegetation is vulnerable to trampling,

drought, grazing, nutrient deficiencies, toxins, and pests, and may require special

management measures at times.

It has been shown in slope reconstruction projects that soil bioengineering systemscan withstand heavy rainfalls immediately after installation. Even if established

vegetation dies, the plant roots and surface residue may continue to play an

important protective role during reestablishment.

Figure 3: Life span of small civil engineering and bioengineering structures


11/43


Chapter 2:Plant function

MAIN PLANTSFUNCTION

Soil bio-engineering intervention use plant for soil erosion control

and slope stabilization. The live component have important

biological functions: plants create habitat and sustain biodiversity,

have a positive influence on soil structure. Also plant regulate the

soil water balance and reduce the surface erosion.

ENGINEERING FUNCTION OF VEGETATION-TECHNICAL CAPACITY

Plants are considered like live construction material with have

structural and engineering function. For this is important to know to

use plant capacity for drain, armour, catch, support, reinforce andanchor the soil to avoid erosions and landslides.

HOW TO CHOOSE THE RIGHT SPECIES

To have better result its important use autochthonous material.

Different species have different technical and biological

characteristics: its importantto consider plant capacity to choose

the right species for an intervention. Its important to know

biological properties, stress resistance, the root development and if

the plants do the nitrogen fixation.


12/43


Main function of plants

Soil bioengineering takes advantages of particular characteristics of vegetative

components, alone or integrated with living or non-living structures, to control

erosion and slope instability. Different species of plant, different methods of

propagation or different spatial arrangements of the live material perform differentfunction. For this, when we design an intervention, we have to put clear in mind

the dynamic and the causes of the erosive process, the problem that we want to

solve and the function that the live component and/or the structure have to

perform and the time evolution of the intervention.

Habitat and biodiversity

Plants offer shelter and sustenance to animals and other organisms, thus

enhancing ecosystem's diversity and, consequently, stability.

Positive Influence on soil structure

Soil is composed of sand, silt, clay and

organic matter. The minute particles of

sand and silt are bound by clay and

organic matter into aggregates. The

arrangement of aggregates gives soil its

structure. Good soil structure has

adequate spaces (pores) between

aggregates that allow water and air to

enter the soil and drain easily, and at the

same time hold enough moisture to allow a regular plant growth. Poor soil

structure has few aggregates and few pores between soil particles. Good structure

helps to make a fertile and resistant to erosion soil. Aggregation in the surface soil

is favoured by surface residue, organic matter, live roots secretions and soil

microorganisms activity. A continuous supply of organic materials and roots of

living plants are needed to maintain good soil aggregation.

Figure 4 A well aggregated soil have a range of pore sizes. This medium size soil crumb is

made up of many smaller ones. Very large pores occur between the medium size aggregates

(FAO).


13/43

Chapter 2Plant Function 13

Figure 5 A dense vegetation cover protects the soil and helps regulate waters movement and

surface erosion. The figure shows the variations in erosion and runoff with the variation of

soil coverage


14/43


Plant regulation of water balance and reduction of surface erosion

Rainfall Interception

Foliage and plant residues absorb rainfall energy; reduce the drop impact (see

belowArmour function andfigure 7), preventing soil compaction and surface soil

erosion.Infiltration

Root and plant residues help maintain soil porosity and permeability. Run-off

occurs on surfaces when rain falls faster than it can be absorbed into the soil. The

natural consequence of reduced infiltration is increased run-off.

Retardation

As runoff water moves down a slope, it increases in speed and increases the potential

for erosion. The volume of sediment also increases because the transported particles

scour and dislodge more soil particles. Above-ground residues, herbaceous, and to a

lesser extent woody vegetation, increase surface roughness and slows run-offvelocity and so have a fundamental role in mitigating erosion. Along a slope with

a dense vegetation cover, the speed of flow of the water is about of that which

would be, in equal rain condition, on soils without vegetation: consequently, the

erosive action, which varies exponentially, can drop down to 1/16 (figure 5).

Restrain

Root systems physically bind or restrain soil particles while above-ground

residues filter sediment out of run-off (see Catch functionbelow).

Water absorption, Plant Transpiration and Evaporation

The vegetation defends water and soil by keeping the amount' of water necessary

for the vital functions, thereby regulating the flow of surplus gradually, so not

occurs excessive run off and solid transport. Depletion of soil moisture by plants

reduces the quantity of run-off and delays onset of saturation. A saturated soil, or a

very moist one, have less intern cohesion and this can leads, on slope, to land

movements or landslides.

Figure 6: Influence of vegetation on water balance


15/43


Figure 8: On a slope the movement of the

detached particles is down slope due to the

gravity force.

Figure 7: The drop energy destroys aggregate

(soil crumbs) and the resulting fine particles

can be easily transported and, also, fill the

surface micro-pores, decreasing g the

permeability of the soil.In bare soil the detachment and transport of

soil particles is more than in a covered soil.


16/43


Engineering Function of Vegetation11- Technical capacity

Drain Function

Armour Function

Catch Function

Reinforce Function

Support Function

Anchor Function

Drain Function - application

The planting configuration of the vegetation can enhance drainage or water

infiltration. Diagonal and angled grass or vegetation lines (see figure 9) can

canalise the water, avoiding it to reach the erosive speed and avoiding saturation

and slumping of material. Contour line (as contour line fascines see leaflet

number 3) catches debris and reduces the run off by increasing the water

infiltration. The water infiltration increase because the contour line configuration

cut the slope, slows down the water flow that loose erosive energy and can

penetrate easily into the soil. On a steep slope, when the soil is saturated the

weight of soil is often sufficient to exceed the forces holding the soil in place.

Under these circumstances, large masses may slip downhill, further losing their

internal cohesion as they fall and becoming loose heaps at the bottom which canbe easily be detached and transported by the run-off with risk of mud flood. So, in

case of instable (e.g. incohesive material) on a steep slope with drainage problem

is necessary (instead of increase infiltration) avoid soil saturation, removing the

exceeding water. Down slope configuration can evacuate surface water quickly,

but can also help erosion in very erodible lands or very steep areas. One of the

soil-bioengineering interventions are the Drainage fascines (see leaflet number 4)

that are made assembling long bundles of live branches placed in existing

rill/small gully (or in a trench), secured with live or dead pegs and covered with

soil. They are similar to contour line fascines but instead of being oriented along

the contour they are placed down-slope, following the maximum slope line, or

angled (figure 10). They perform immediate sub-surface drainage, as the water is

channelled through the straight branches: provides rapid stabilization at mid

depth, where excess moisture has created instability, thus reducing shallow slips.

The cuttings used to form the fascines will eventually put out roots and sprout,

developing into a strong line of vegetation that reduces erosion, while the excess

moisture continues to drain from the lower end.

11Resource Manual on Flash Flood Risk Management: Module 3: Structural Measures, Arun

Bhakta Shrestha Ezee Shrestha Ezee GC, Rajendra Prasad Adhikary and Sundar Kumar Rai.

International Centre for Integrated Mountain Development, Nepal, 2012


17/43


18/43


Figure 12: live wattling

Catch Function - application

Eroding material moving down a slope, as a result

of gravity alone or with the aid of water, can be

intercepted by stems the vegetation (grass stems

and trunks) or by protruding element of the bio-engineering structure.

Bioengineering Requirement:

Strong, numerous and flexible stems

Soil B.E. Examples:

Planting large shrubs with many stems;

Live Palisades,

Vegetated Contour lines:

Brush layeringleaflet number 2,

Live wattlingleaflet number 5,Contour line fascines after sproutingleaflet number 3

Civil Engineering equivalent Catch wall.

Support Function - application

Support the soil mass by buttressing and arching.

Bioengineering Requirement

Extensive deep and wide spreading root

systems;

Many strong fibrous roots.

Soil B.E. Examples:

Large trees;

Vegetated gabions wallsee leaflet number 6.

Civil Engineering equivalent: Retaining walls.

Reinforce Function - application

Reinforce the soil by providing a network of roots that increases the geotechnical

properties of the soils: resistance to shear, tensile strength and the cohesion.


Plants with extensive roots with many splits; Many strong fibrous roots.

Soil B.E. Examples:

Densely rooting clumping grasses planted in

lines;

Shrubs and trees which develop lateral roots;

Jute netting with planted grass.

Civil Engineering equivalent: Reinforced earth.

Figure 13: Retain gabion wall


19/43


Anchor Function - application

Anchor the surface material by extending roots through potential failure planes

into firmer strata below. Big tap roots are good for deeper failure plane.


Plants with deep, strong, long vertically oriented rootsSoil B.E. Examples:

Deeply rooting shrubs and trees;

Combination of anchors and trees.

Civil Engineering equivalent: Soil anchors.

Figure 14: Different species have different growth characteristics

(height, shape, rooting capacity, etc).


20/43


How to choose the right species

Since we work with live material the choice of the species is influenced by

ecological aspects. Plant species must be suitable for the specific needed function

and adapted to the sites climate and soil conditions. To ensure appropriate species

to be used is necessary to study the natural vegetations on site, to carry out

searches on technical literature12and to get advice by a specialist about available

species and cultivars.

Autochthonous Material

The best result can be reach using autochthonous living materials (i.e. plant, seed,

parts of plants and plant communities) collected near the construction site itself

and from close around. They are always suited best because they have already

adapted to the site: well suited to the climate, soil conditions, and available

moisture. It is a good candidate for survival. They are always the best choice

because they are already adapted to the site (to the climate, to the soil conditions,

and to the available moisture). In the first survey of the future constructions site

must always include an inventory of the living building materials available in site:

examine whether parts of the natural vegetation have to be removed during the

construction and whether can be re-use later on13. Preferred candidates are pieces

of closed vegetation, which are lifted off as transplants together with topsoil and

roots, stored temporarily, if necessary, and then replaced further material or twigs,

as well as vegetative propagating herbs and grass species as rhizome cuttings or

divided stolons. Plants which are valuable, rare o worth protecting and preservingfor other reason can be dug out as individual plants together with their root ball

and reset as transplants.

Appropriate vegetation material, like cuttings, is often obtained from natural

poplar and willow stands. Using local materials is cost effective because plant

costs are limited to labour for harvesting, handling, and direct costs for

transporting the plants to the site.

Where living building material cannot be obtained from the construction site or

from natural vegetation is necessary to purchase the live material: in this case is

good to choose material that is originates from areas that are largely identical tothe site of application.

Biological Properties

The plants possess biological and technical properties which, together, constitute

the bio-technical properties. Technical proprieties are the capacity to fulfil the

engineering function explained in the previous paragraph (Engineering Function

of Vegetation).

12It is a good book for choose the right plant in the Europe context: Ischiechtl 1994, 2001.

13Ingenieurbiologie: Handbuch Bautypen


21/43


Possibility of easy propagation (capacity of vegetative or seeds

propagation, development of the roots, etc);

Growth capacity and rapid growth;

Capacity to colonize sterile land and to trigger the ecological succession;

Resistance: to salt, to flooding, to debris accumulation, to drought, coldresistance.

Some plant species have the capacity to develop new plant from branches or even

parts of them, this ability is called ability to vegetative or asexual reproduction.

We will speak about how to reproduce plant using one of these techniques in the

paragraph How to prepare cutting for Soil-Bioengineering.

The capacity to reproduce a new plant from branch section is connected with the

capacity of the plant to produce adventitious roots from the stem and trunk. This

capacity gives also to some species the possibility to create new root when a part

of the stem is coated by soil after a land slide or an accumulation of debris (seenext paragraph).

Figure15:Adventitios root

Stress Resistance:

Debris accumulation or landslide

Most of the plants are dying back if coatings by landslide or other debris

accumulation. By the way few plants can bear without damage coatings of soil up

and debris (silt or gravel) to 1-2 m in height: from stems buried, near the new

ground level, they are able to produceadventitious roots.

There are no study available on the

international literature on Central Asian

plant resistant capacity, the experience and

the observation of the local environment

can give to the technician a lot of

information regarding the local availability

of resistant plant (e.g.: plant growing on

site subject to frequent stone debris flow

are resistant to debris coatings). Figure 16: Resistance to debrisaccumulation


22/43


In Central Europe were tested as debris accumulation resistant the following

plants: alder (Alnus spp.), willow (Salix spp.), poplar (Poplar spp. excluded P.

tremula), ash (Fraxinusspp.), hazel (Corylus spp.), maple (Acer spp. excludedA.

platanoides), privet (Ligustrum spp.), pine (Pinus spp.), Sorbus aucupariaand a

few other trees and shrubs.

Episodic and periodic flooding14

The short duration of submergence, from several hours to several days, may occur

without damage to riparian vegetation, even several times a year. Only few tree

species, Alnus glutinosa (alder), Populus alba (white poplar), Populus nigra

(black poplar), Salix sp. pl. (willows),Fraxinus excelsior(Common Ash), bear a

water stagnation of a long-term to permanent. A gradual submersion is tolerated

more easily than a sudden massive stagnation. In the presence of permanent

artificial stagnation, trees should be shielded with gravel and pebbles just above

the water level, in order to make them able to generate adventitious roots. With

regard to the willows resistance to submersion, it is assumed that all willow

species of Central Europe withstand without damage a submersion of a few days,

while the most sensitive species to submergence is the goat willow(Salix caprea).

Only a few species of willows withstand a prolonged and perennial submersion,

which can occur as a result of the construction of hydroelectric reservoirs. From

experimental observations is shown that the Salix alba (white willow), Salix

fragilis(brittle willow) and Salix pentandra (willow fragrant) withstand prolonged

and even perennials submersion. The height of the flooding should not exceed 2

meters and clearly depends on the height of the tree at the start of submersion.Present in Central Asia:Populus alba, Populus nigra, Salix spp: Salix triandra,

Salix alba, Salix pentandra, Salix cinerea. DO NOT use Salix caprera!

Nitrogen fixation

More ecologically efficient plants are those living in symbiosis with nodule-

forming bacteria and fungi (micorrhizae) live on the root of plants and produce

nitrogen, thus creating the effect of automatic permanent nitrogen fertilization.

For Soil Bio-engineering purpose the most important species in Europe with these

characteristics are alder and legumes; in Central Asia is interesting Elaeagnusangustifolia15(Russian: ; Tajik: - Sunjit).

Root development

In assessing the engineering function of plants, rooting depth is very important.

Root development depends to species (figure 17), soil conformation, water table

14Manuale di Ingegneria Naturalistica, Regione Lazio; volume 3 Sistemazione dei versanti,

capitolo 12 Biotecnica delle specie vegetali, F. Palmeri, P. Cornelini. 15

Nitrogen fixation by Elaeagnus angustifolia in the reclamation of degraded croplands of Central

Asia,Khamzina A,Lamers JP,Vlek PL., Center for Development Research, Bonn, Germany.
http://www.ncbi.nlm.nih.gov/pubmed?term=Khamzina%20A%5BAuthor%5D&cauthor=true&cauthor_uid=19324691http://www.ncbi.nlm.nih.gov/pubmed?term=Lamers%20JP%5BAuthor%5D&cauthor=true&cauthor_uid=19324691http://www.ncbi.nlm.nih.gov/pubmed?term=Vlek%20PL%5BAuthor%5D&cauthor=true&cauthor_uid=19324691http://www.ncbi.nlm.nih.gov/pubmed?term=Vlek%20PL%5BAuthor%5D&cauthor=true&cauthor_uid=19324691http://www.ncbi.nlm.nih.gov/pubmed?term=Lamers%20JP%5BAuthor%5D&cauthor=true&cauthor_uid=19324691http://www.ncbi.nlm.nih.gov/pubmed?term=Khamzina%20A%5BAuthor%5D&cauthor=true&cauthor_uid=19324691


23/43


Figure 17:Different specie have different root development.

(figure 19), and availability of nutrient and humidity. Roots growin the directionof

thewaterand nutrient; in heavilyfertilized or humidsoils plants develops shallow

root system.

Figure 18: Influence of soil

conformation in root development


24/43


Figure 19: Different species have difference development in reletion with the water table


25/43

Chapter 3Design Consideration and Techniques 25

Chapter 3:Design Consideration and

Techniques

CONSIDERATION-FOR A GOOD DESIGN

Before precede to the design of the intervention it is necessary

study Topography and exposure, Geology and soils, Hydrology, and

follow some general Design considerations.

HOW TO PREPARE CUTTING FOR SOIL-BIO-ENGINEERING

Cutting are required for a lot of different soil bio-engineering

techniques. It is important to plant in the right season, and to take

care during preparation, storage and layering. SOIL BIO-ENGINEERING TECHNIQUES DESCRIPTION:

Some useful intervention for slope protection and stabilization

are: check dams, Palisade, Brush layering, Contour line fascines,

Drainage with fascines, Wattling, Gabions, Riprap, Pole or Live

stake planting. It is always important protect cutting and the trees

from the animal damages.


26/43


Consideration

For planning a soil bio-engineering intervention has to be considered the site

topography, hydrology, geology, soils and vegetation.

Topography and exposure16

Note the degree of slope (figure 20) in stable and unstable areas. Also note the

presence or lack of moisture17. The likely success of soil bioengineering

treatments can best be determined by observing existing stable slopes in the

vicinity of the project site. Note the type and density of existing vegetation in

areas with and without moisture and on slopes facing different directions. Certain

plants grow well on east-facing slopes, but will not survive on south-facing

slopes. Look for areas of vegetation that may be growing more vigorously than

other site vegetation. This is generally a good indicator of excess moisture, such

as seeps and a perched water table, or it may reflect a change in soils.

Figure 20: Calculate the degree

of the slope:

Materials: Protractor String

Weight (heavy washer or

something similar) Yard or

meter stick. Tie the weight to

one end of the string. Use the

other end of the string to secure

the protractor to the yardstick

as the diagram indicates.18

Geology and soils

Ask to the local people about the story and the evolution of the area, study the

type of deposits(colluvium, glacial, alluvium, other). Use the soil survey report,

if available. Determine soil type and depth. Soil B.E. can be limited by the

available medium for plant growth. - Rocky or gravely slopes may lack

sufficient fines or moisture to support plant growth, or hard pans or compacted

soils may prevent the required root growth.

Consult geologists and soil scientists if planning to do important intervention in

instable area.

16Soil Bioengineering for Upland Slope Protection and Erosion Reduction, Engineering Field

Handbook, October 1992, United States Department of Agriculture Natural Resources

Conservation Service17

As above.18

Slope Stabilization and Erosion Control Using Vegetation: A Manual of Practice for Coastal

Property Owners. Myers Rian D.; Shoreland and Coastal Zone Management Program, Washington

Department of Ecology. Olympia. Publication 93-30. 1993.


27/43


Note evidence of past sliding. If site evidence exists, determine whether the slide

occurred along a deep or shallow failure surface. Leaning or deformed trees may

indicate previous slope movement or downhill creep. In addition to site evidence,

check aerial photos (such as free satellite image from Google earth19), which

reveal features that may not be apparent from a site can visit.Avoid extensive grading and earthwork in critical areas and perform soil tests to

determine if vigorous plant growth can be supported.

Hydrology

All the hydrology analysis has to be carried out at watershed level.

Observe Drainage Patterns: water causes soil erosion or slope instability. A

visual observation of the drainage characteristics on the property should be

conducted to determine the extent of surface water runoff. The best time to do this

is during periods of heavy rainfall. Any observations on the direction and speed of

runoff should be noted. Any catch basins, ditches, gullies, or general areas of

concentrated water flow should also be noted. Determine the drainage area

associated with the problem area. Note whether water can be diverted away from

the problem area. Determine the annual precipitation. Are there concentrated

discharges? Calculate peak flows or mean discharge through the project area. If a

seep area was noted, locate the source of the water. Determine whether the water

can be intercepted and diverted away from the slope face.

Design considerations

Retain existing vegetation whenever possible, vegetation provides excellentprotection against surface erosion and shallow slope failures. Limit the removal of

vegetation to the smallest practical size. Remove and store existing woody

vegetation that may be used later in the project. Schedule land clearing during

periods of low precipitation whenever possible. In the first centimetres of soil

there is the fertility of the soil, topsoil removed during clearing and grading

operations can be reused during planting operations. During construction protect

the area from temporary erosion. Install a suitable drainage system to handle

increased and/or concentrated runoff caused by changed soil and surface

conditions during and after construction. Planning and coordination are needed toachieve optimal timing and scheduling. The seasonal availability of plants or the

best time of year to install them may not coincide with the construction season or

with tight construction schedules. In some cases, rooted stock may be used as an

alternative to unrooted dormant season cuttings but they are more expensive.

19GoogleGoogle

http://www.google.com/intl/ru/earth/index.html
http://www.google.com/intl/ru/earth/http://www.google.com/intl/ru/earth/http://www.google.com/intl/ru/earth/http://www.google.com/intl/ru/earth/http://www.google.com/intl/ru/earth/http://www.google.com/intl/ru/earth/http://www.google.com/intl/ru/earth/http://www.google.com/intl/ru/earth/http://www.google.com/intl/ru/earth/


28/43


29/43


All cuttings must have leaf buds on the stem so the cutting can grow leaves while

it is rooting, thus producing energy. Select cuttings with leaf buds near the top of

each cut line. Do not use branches with flower buds: they typically occur at the

tips of branches produced during the last growing season, for eliminate flower

buds trim branch tips of less of 6 mm diameter.

Storage

To maintain the vitality of the cutting is necessary to prevent drying, heating and

mechanic damage. To reduce drying remove small branches and whips as soon as

possible after cutting. Best result can be reach if the cuttings are planted within 24

hours from the recollection from the parent plant. The cuttings have to be stored in

the shade, cover with moist soil or store in water. Store in longer pieces (90 120

cm) reduce drying. The branches can be cut shorter late, just before laying,

according with the construction requirement.

Figure 23: Cutting storage before layering: in the shade and in fresh water

Layering

Drive cutting in the soil respecting the direction of growth (if the wrong end is put

in the ground the stake will die) and assure that at least of the cutting is in thesoil; leave 515 cm (about ) above ground surface so they can sprout leaves.

Figure 22: Cutting preparation

from a stored branch.


30/43


Figure 24: Use an iron

bar to prepare the

planting hole

If placed horizontally or inclined the cutting will produce

more roots (unlike those placed vertically). Use an iron bar

to start the hole in hard soils. Drive into the ground with a

rubber mallet to avoid damaging them. If you damage the

upper part (e.g.: using a hard hammer) after planting cut thedamaged stump! If planted while dormant cutting should be

show shoots (leaves and small branches) in spring. If

planted during the growing season: it may take a full year

or two to see results. To increase survival: watered once a

week during their first growing season.

Figure 25 Shoots: evidence of successful rooting.


31/43


Soil Bio-Engineering Techniques Description

We briefly describe some techniques, without discriminate in the different bio

engineering categories. For the techniques that have a technical leaflets refer to

them for the construction guideline.20

Check dams

Check dams are often used on sites with slopes that are steeper than desired. A

stone check dam is a barrier constructed of stone or wood (see Brush wood Check

dam and palisades) that reduces the flow velocity of runoff, while minimizing

channel erosion and promoting sediment deposition. During rainfall the water that

enter in the gully (or swale or ditch) is pounded temporarily behind the check

dam, allows sediment to settle out, while allowing some water to infiltrate and

evaporate. The water that remains is slowly passed through the permeable check

dam continuing on towards the outfall. In high flow situations, runoff is conveyedover the top of the dam.

Basic Construction guidelines: Depending upon the slope of the channel

multiple check dams may be needed to control runoff velocity. The distance

between two check dam depend on slope and on the height of the dam (see figure

26). The maximum spacing between the dams should be such that the toe of the

upstream dam (A) is at the same elevation as the top of the downstream dam (B).

The center of the check dam should be, at a minimum, 15 cm lower than the edges

to allow water to flow over the top of the structure.

Functions: Slow down water flow, help sedimentation and formation of gradons,

caches debris.

Advantages: Fast and simple protection; big securing effect, resistant to damage,

applicable in slope with big volume of debris flow (especially the reinforced

check dam). It can be used up to about 60.

Disadvantages: Labour intensive. Stone check dam required big quantity of

stone, so the construction is limited by the availability of material. Reinforced

check dam required expensive materials (iron rod and wired).

20Cesvi published 6 leaflets, annexed to this publication: Leaflet number 1: Live Palisades; Leaflet

number 2: Brush Layering; Leaflet number 3: Contour Line Fascines; Leaflet number 4: Drainage

Fascine; Leaflet number 5: Live Wattling; Leaflet number 6: Vegetated Gabions Gravity Retaining

Wall.

Figure 26: distance between check dams


32/43


Stone Check dam

Reinforced Check dam

Figure 28: reinforced check dam.

It is formed by iron rod (armature) and wire, connected similar to wattling, and

stones. The distance between the armatures is set up accordance the size of stones.

The wire is interweaved horizontally between each armature, so the final result

looks like square net (figure 28). The stones are put in both sides of check dam.

Brush wood Check dam

Advantages: applicable when isnot possible to find stone for the

stone check dam. It is stronger

than a palisade.

Figure 27 Stone check dam: the central part of the dam have to be lower than the edge to

invite the water to pass in the center of the stone line.

Figure 29: Brush wood check dam


33/43


PalisadeLeaflet number1

It is a wall consisting of living uniform

stakes of live material driven into the

ground (one third of their length), close

to each other to form a palisade. The topends are cut plane and tied to a

horizontal (living or dead) pole that ties

in the ground at both sides of the gully.

Palisades are used to promote deposition

in rills, V-shaped gullies and

rehabilitation in fine soils (clay, sand,

loess, loam).

Functions: Reduce slope in gullies and

tributaries, encourage deposition ofsediments especially in fine soils.

After sprouting the resulting vegetation

becomes the major structural component;

contribute to soil moisture depletion

through transpiration.

Trap material moving down the slope,

form a strong barrier and reinforce the

slope especially once cuttings developed

the root.

Advantages: Quickly and easily built, immediately effective, usually grows well,

cheap if material at site is available. Filter effect.

Disadvantages: Limited width (about 6 m) and length (2-4 m). Availability of

material restricted (long, straight poles). Only for restricted water and debris flow.

Brush layering Leaflet number 2

It is made of living cuttings planted in line, on terraces across the slope, following

the contour, cover with soil with just the tips sticking out. It use for stabilization

ofshallow earth slumps and loose soil slopes and gullies.

On contour line prevents thedevelopment of rills, if angled, the brush-

layering helps to drain.

Functions:Woody cuttings reinforce and

armour the slope immediately.

The portion of the brush that protrude

assist in retarding run off and reducing

surface erosion.

Figure 30: palisade with double horizontal

pole.

Figure 31: Brush layering, slope section.


34/43


After root and sprout develop into a strong line of vegetation that deplete soil-

water through transpiration and interception, break up the slope length into series

of shorter slopes, trap debris creating

terraces, reinforce the slope with the

roots adding significant resistance tosliding or shear displacement.

Advantages: It is simple and provides a

very strong and low-cost barrier,

especially on loose debris of slopes.

Disadvantages: The construction of the

layers gives rise to a considerable level

of disturbance to the slope. Brush

layering should only be used on slopes

consisting of loose material.

Fascines

Structures consisting of bundles made with live plant material anchored to the

ground using pegs, which in some cases can also be made from live plant material

(cuttings).

Used in two type of intervention:

Stabilizing the base of a stream bank

Slope stabilization

Reinforce slope - Contour line fascinesDrainageDrainage fascinesorLive Pole drain

Below are described contour line fascines and drainage fascines: for more

information seeLeaflets number 3 and 4.

Contour line fascinesLeaflet number 3

They are fabricated from woody species, such as shrub willow or shrub dogwood,

into sausage-like bundles, which are placed with the stems oriented generally

parallel to the slope contour or slightly angled.

Functions: After rooting and spouting develop into a strong line of vegetationthat depleting soil-water through transpiration and interception; dissipate the

energy of downward moving water, trap debris and provide a series of benches on

which grasses and eventually brush and trees establish more easily. Increase

infiltration.

Advantages: Simple and

low cost erosion control

measures, which is

effective even after silting.

Very adaptable to the

existing morphology,

Figure 32: Brush layering construction.

Cesvi, Khovaling, Tajikistan.

Figure 33: Fascine for contour line


35/43


requires little soil work, suitable for steep rocky slopes where digging is difficult.

The maximum slope is about 45.

Disadvantages: A large amount of straight and long plant material is needed.

Form a physical barrier only after sprouting.

Drainage with fascines - Leaflet number 4

Use for wet slope stabilization and drainage. They are positioned down-slope in

existing rill/small gully (or in a trench), secured with live or dead pegs and

covered with soil.

Functions:Immediate sub-surface drainage with rapid stabilization at mid depth.

After spouting develop into a strong line of vegetation that reduces erosion, while

the excess moisture continues to drain from the lower end.

Advantages: Simple and low cost erosion control measure, which is effective

even after silting. Very adaptable to the existing morphology, requires little soil

work.Disadvantages:A large amount of straight and long plant material is needed. Do

not form a physical barrier immediately. They can only drain a limited amount of

water, up to 5 litres per second. The maximum slope is about 35.

Wattling Leaflet number 5

Wattling, or rooted fences, is used over steep slopes in loose materials, affected by

superficial landslide sand erosion, where vegetation cannot naturally establish.

Long live cuttings (e.g.: willow) are interweaving horizontally around vertical

plant stakes, and/or rebar, driven into the groud.

Soil is filled in behind the fence. Generally done along the contour line.

Functions: Reinforce the slope.

Modify the slope establishing

terraces (breaks up the slope length

into series of shorter slopes), catch

debris and increase infiltration. After

rooting and spouting plays a very

efficient action of consolidation, by

the root system, and drainage, by the

leaf transpiration.

Figure 34: Drainage fascines

Figure 35: Wattling: slope section.


36/43


Advantage: Fast and simple protection; Rooted fences establishes a micro-site for

other plants.

Disadvantages: Large quantities of flexible branches are required. Labour and

material intensive, securing effect is small, easily damaged, thus not sufficient for

persistent rock falls. Applicable only to slope with limited volume of debris flow.It can be used up to about 40. Not suitable on excessively drained soils (the

cuttings dry out and die).

Gabions Leaflet number 6

A gabion isparallelepiped made by metal mesh, interconnected with other similarcontainers to form a monolithic structure. When live cutting or rooted plant or

seeds are added during the gabion constructions we call it vegetated gabions.

Some people confuse gabions with mattress: the function of them is completely

different from the gabions function. Mattresses (figure 37) are flat layer of stone

cover with metallic net. It is used for river bank protection and covering without

structural or retain function.

Figure 36: Wattling reinforced by a stone line (Cesvi, Kujand, Tajikistan)

Figure 37: Mattress: it is different fromgabion! (Photo from internet)

Figure 38: Gabions for river bank protectionand retain (Cesvi, Khovaling, Tajikistan).


37/43


Gabions are used for generally structural purpose: gravity retaining wall, road and

slope-stabilizing structures, reinforcement of shorelines, stream bank (figure 38)

and embankments, channel linings, revetments, weirs, check dams (figure 41), etc,

for erosion and flood control. It is important to notice that traditional net (see

figure 39A) is not adapted for gabions: the main problem is that if in one pointthe wire is broken all the net will be laddered. The best net is hexagonal double

twist galvanized wire mesh net (figure 39 B). More resistant because the twist

construction avoid an easy disintegration Galvanized because can resist longer to

stress and corrosion hazards. Iron rods (figure 39C) can be used to reinforce the

connection with the ground.

The gabions have a easy building shape (figure 40): For a rectangular

parallelepiped shape gabion of 0.6 x 0.6 x 1.2 m are needed 3 m of wire mesh (1.2

m high).For bigger gabions, with cubic shape (1,2 x 1,2 x 1,2), are needed 7.2 m

of wire mesh 1.2 m high.

Advantages: can be built without any mechanical equipment. Rapid effect of

consolidation, fast implementation, Very flexible, able to resist to erosion or

landslides, or seismic tremors. Easy to find suitable living plant material. Great

degree of permeability throughout the structure.

Disadvantages: It is necessary to find the filling material on site. Labour

intensive. It is important that a qualified geotechnical engineer approve the

structural wall design.

Figure 39: A. Traditional wire mesh, B. double twisted net, C. Iron rods

Figure 40: Gabions shape:

Cubic and Parallelepiped.


38/43


Figure 41: AB Gabions Check dam and Gabions Stream dikes: for energys flow reduction

Cesvi, Khovaling, Tajikistan

Vegetated Gabions Gravity retaining wall - Leaflets number 6

A retaining wall is a structure designed and

constructed to resist the pressure of soil

thanks to the mass of the structureFunction: Stabilization of slopes and

landslides, water drainage and plant cover

restoration, great degree of permeability.

The living plant material, once taken root

and developed, contributes to the overall

consolidation, through the root system, and

drainage effect, by means of the leaf

transpiration.

Advantages:Rapid effect of consolidation, fast implementation. Its very flexiblestructure: able to resist, without serious deformation, to settling and/or subsidence

of the soil due to erosion or landslides, or seismic tremors. Usually is easy to find

in the area suitable living plant material with the possibility of re-creation of

natural habitats and good landscaping. It can be built without any mechanical

equipment (all stages of excavation and laying of foundations can be carried out

by hand). It may constitute a basis for further interventions of bioengineering.

Disadvantages: The filling and closure of the wire cages is labour intensive. Its

necessary to find the filling material on site. The structural wall designer requires

the approval of a qualified geo-technical engineer.

Figure 42: Retain gabion wall, Cesvi,

Khovaling, Tajikistan

Figure 43: Calculation for the design of a retain wall


39/43


Riprap

Riprap is the pitching of stones for slope

protection. In vegetated riprap vegetation (brush

and or grass) is inter planted between the stones.

Riprap can be used in slopes (stream bank,shoreline, toe wall, revetment, roadside slopes, and

gully head) and water course (spillway, waterways,

and gully floor).

We can divide them in two groups, one integrated

with vegetation and the other one without:

A. Stone riprap without vegetation21. Generally used in revetment, stream bank,

water course.

B. Riprap with vegetation22.Generally used in toe wall / roadside, gully beds and

head.Function: Reinforce and armour the slope against erosion. It allows seepage to

flow out between the stones.

Advantages: Stones are not dislodged once the vegetation is established. Good

drainage through wall by the plants.

Disadvantages: Regeneration of vegetation is obstructed by stones. It is relatively

expensive to carry out in large scale. It cannot be used in toe protection more than

2 meters in height and slope greater than 60, in long slopes length, in very steep

gullies (more then 45) or gullies where plentiful debris flow occurs. Use on gully

floors with a maximum slope of 45 and with only very small amounts of debris

flow.

21BIWMP, 2003, Ohio Department of Natural Resources.

22Howell, 1999.

Figure 44: Vegetated riprap

Figure 45: Revetment overflow water way. Cesvi, Khovaling, Tajikistan.


40/43


Pole or Live stake planting

Live staking involves the insertion and

tamping of live, rootable vegetative

cuttings into the ground. If correctly

prepared and placed, the live stake willroot and grow.

Function: A system of stakes creates a

living root mat that stabilizes the soil by

reinforcing and binding soil particles

together and by extracting excess soil

moisture. Most willow species root

rapidly and begin to dry out a slope soon

after installation. It is appropriate for

repair of small earth slips and slumpsthat frequently are wet.

Advantages: May be used for pegging down surface erosion control materials

(e.g.: seedling mat). It enhances conditions for natural invasion and the

establishment of other plants from the surrounding plant community. It can be

used to stabilize the area of intervention between other soil bioengineering

techniques, such as live fascines.

Disadvantages: A technique for relatively uncomplicated site conditions when

construction time is limited and an inexpensive method is necessary. The

stabilization effect starts after 6 months -1-2 years.

Basic Construction guidelines: The cuttings are usually Branches of easy rooting

plants (like willow, poplar, mulberry and sea-buckthorn) 60-90 cm long of 1.5 to

5 cm in diameter from one year to 6 years old branches. For final size

determination, refer to the available cutting source. The materials must have side

branches cleanly removed and the bark intact. The basal ends should be cut at an

angle for easy insertion into the soil. The top should be cut square and flat.

Materials should be installed the same day that they are prepared.

Drive cutting in the soil respecting the direction of growth (if the wrong end is put

in the ground the stake will die) and the right angles. Be sure that at least 1/4 of

the cutting is in the soil and firmly packed soil around it after installation. Theinstallation may be started at any point on the slope face. The live stakes should

be installed using triangular spacing (from 2-5 cutting/m2 to 5-10 cutting/m2).

Do not split the stakes during installation. Stakes that split should be removed and

replaced. An iron bar can be used to make a pilot hole in firm soil. Drive the stake

into the ground with a dead blow hammer (hammer head filled with shot or sand).

Figure 46: Live stakes


41/43


Trees and cutting protection

Trees protection with recycled plastic

bottle. The bottle are cut longitudinally

for enlace the trunk to grow.

Functions: Protect tree and soil-bioengineering interventions from

animal. Create a microclimate (enhance

moisture and temperatures). It is a low

cost alternative to rigid plastic shelter

(photo-degradablefigure 47).

Figure 47: trees protection from animal damage: rigid pho-degradable plastic shelter and plastic

bottles


42/43

CesvI, established in 1985, is a secular, independent association,

working for global solidarity. In the values which guide Cesvi, the moral

principle o human solidarity and the ideal of social justice are

transformed into humanitarian aid and development, reinforcing an

affirmation of universal human right. Cesvi believes strongly that helpingthe underprivileged in developing countries, or those I difficulty due to

war, natural calamities nd environmental disaster, does not help only

those who soffer, but contributes also to the well-being of all of us on the

planet, our common home to be look ed after for future generations.

CesvIhas been in Tajikistan since 2001: the main area of intervention

are agriculture, water supplies and development of local economy, with

specific focus on vulnerable people, to improve socio-economic

conditions and living standards. CesvIhas 3 offices in Tajikistan:

Dushanbe, Khujand, Khovaling


43/43

This publication has been produced with the assistance of theEuropean Union. The contents of this publication are the sole

responsibility of Cesvi and the implementing partner and can in noway be taken to reflect the views of the European Union.

CesvITajikistan

Dushanbe Office: 37, Buzurgzoda Street

tel. +992 37 224 67 28E-mail: [email protected]

Khovaling Office: 8 of March StreetTel +992 934098724

[email protected]

www.cesvi.org
mailto:[email protected]:[email protected]:[email protected]://www.cesvi.org/http://www.cesvi.org/mailto:[email protected]

erosion control tajikistan2013

Documents