Desire for Greener Land

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Jessour Tunisia - Jesser, Katra (Arabic) Jessour is an ancient runoff water harvesting technique widely practised in the arid highlands Jessour technology is generally practised in mountain dry regions (less than 200 mm annually) with medium to high slopes. This technology was behind the installation of very old olive orchards based on rainfed agriculture in rugged landscapes which allowed the local population not only to ensure self-sufficiency but also to provide neighbouring areas many agricultural produces (olive oil, dried figs, palm dates, etc.). Jessour is the plural of jessr, which is a hydraulic unit made of three components: the impluvium, the terrace and the dyke. The impluvium or the catchment is the area which collects and conveys runoff water. It is bordered by a natural water divide line (a line that demarcates the boundary of a natural area or catchment, so that all the rain that falls on this area is concentrated and drained towards the same outlet). Each unit has its own impluvium, but can also receive excess water from upstream units. The terrace or cropping zone is the area in which farming is practised. It is formed progressively by the deposition of sediment. An artificial soil will then be created, which can be up to 5 m deep close to the dyke. Generally, fruit trees (e.g. olive, fig, almond, and date palm), legumes (e.g. pea, chickpeas, lentil, and faba bean) and barley and wheat are cultivated on these terraces. Although the jessour technique was developed for the production of various agricultural crops, it now also plays three additional roles: (1) aquifer recharge, via runoff water infiltration into the terraces, (2) flood control and therefore the protection of infrastructure and towns built downstream, and (3) wind erosion control, by preventing sediment from reaching the downstream plains, where windspeeds can be particularly high. In the Jessour, a dyke (tabia, sed, katra) acts as a barrier used to hold back sediment and runoff water. Such dykes are made of earth, and are equipped with a central and/or lateral spillway (masref and/or manfes) and one or two abutments (ktef), assuring the evacuation of excess water. They are trapezoidal and measure 15-50 m in length, 1-4 m in width and 2-5 m in height. In old units, the dyke is stabilised with a covering of dry stones to overcome the erosive effects of water wave action on the front and back of the dyke. The spillway is made of stones arranged in the form of stairs, in order to dissipate the kinetic energy of the overflow. This technology is currently encountered in the mountain ranges of Matmata of South Eastern Tunisia where the local agricultural activities are based mainly on rainfed agriculture and livestock breeding. However, high rates of migration to cities may threaten the long-term maintenance of those structures. SLM Technology: Jessour, Tunisia DESIRE – WOCAT 2012 Above left: Jessour is the plural of a Jessr which is the hydraulic unit comprising a dyke, spillway, terrace (cropping area: fruit trees and annuals), and impluvium (runoff catchment area). (Photo: van Delden H.) Above right: Jessour is an ancient runoff water harvesting technique widely practised in the arid highlands of southern Tunisia. After each rainfall event, significant volumes of runoff water accumulate on the terrace and infiltrate into the soil to sustain trees and crops. The spillway ensures sharing the runoff water with downstream users and the safe discharge of excess water. (Photo: Ouessar M.) Location: Medenine Region: Beni Khedache Technology area: 100 km 2 - 1,000 km 2 Conservation measure: structural Stage of intervention: mitigation / reduction of land degradation Origin: land users - traditional (>50 years ago) Land use: grazing land Climate: arid, subtropics WOCAT database reference: QT TUN09 on cdewocat.unibe.ch/wocatQT DESIRE site information: www.desirehis.eu/en/zeuss-koutine-tunisia Related approach: Dryland watershed management approach (QA TUN09) Compiled by: Mohamed Ouessar, Mongi Ben Zaied, Mongi Chniter, Institut des Régions Arides (IRA) Date: 22nd Sep 2008 updated 10th Jun 2011 109
Classification Land use problems: Loss of surface water (runoff), problems of flooding, water erosion, soil degradation, drought Land use Climate Degradation Conservation measure annual tree and shrub cropping cropping (rainfed) (rainfed) extensive grazing land (before) tree and shrub cropping (after) Stage of intervention Prevention Mitigation / Reduction Rehabilitation Soil depth (cm) 0-20 20-50 50-80 80-120 >120 arid, subtropics soil erosion by water degra- water: loss of dation: topsoil / surface aridification erosion Origin Land user's initiative: >50 years Experiments / research Externally introduced Main causes of land degradation: Direct causes - Human induced: crop management (annual, perennial, tree/shrub) Direct causes - Natural: change of seasonal rainfall, heavy / extreme rainfall Indirect causes: poverty / wealth Main technical functions: - harvesting of runoff water / water trapping - increase of infiltration - sediment retention / trapping, sediment harvesting Environment Natural Environment Average annual rainfall (mm) > 4000 3000-4000 2000-3000 1500-2000 1000-1500 750-1000 500-750 250-500 < 250 Growing season(s): 180 days (Oct - Mar) Soil texture: medium (loam) Soil fertility: very low Topsoil organic matter: low ( 4000 3000-4000 2500-3000 2000-2500 1500-2000 1000-1500 500-1000 100-500
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Desire for Greener Land Options for
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DESIRE - WOCAT Desire for Greener L
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Co-published by University of Bern,
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Cross-slope barriers Progressive be
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The present DESIRE publication desc
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Contributing authors and DESIRE con
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Desire for Greener Land - Options f
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XIV DESIRE - WOCAT Desire for Green
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Figure 1: Desertification vulnerabi
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In DESIRE, WOCAT methods and tools
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Part 1
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8 DESIRE - WOCAT Desire for Greener
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Figure 1: Methodological framework
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to Russia and China (see Table 1).
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DRI = 5.4 Very high desertification
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Table 2 provides a more detailed de
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decision. This leads to solutions b
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Aims and objectives This penultimat
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Figure 7: The DESIRE Project has fo
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References: n EEA-European Environm
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Area (x1000 Ha) Major land use type
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Major land degradation types per st
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Rate of degradation per study site
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Production services were affected o
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% of area under conservation measur
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Figure 16: Effectiveness of conserv
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Conservation impact on ecosystem se
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Analysis of SLM technologies Introd
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Table 2: WOCAT categories of SLM me
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Origin of technology SLM technologi
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Table 3: Sensitivity of and toleran
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No. of case studies Land Ownership
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No. of case studies Increased farm
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No. of case studies Increased plant
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Problem, objectives and constraints
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Impacts of the Approach Improved su
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Input: - Equipment (machinery, tool
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Problems, objectives, and constrain
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Desire for Greener Land Opopejo Qui
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2.2 Mapping case studies This secti
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Land recommendation Land conservati
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Portugal - Maçao The Maçao area h
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Italy - Rendina The Rendina area ex
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Greece - Nestos This area has chemi
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Turkey - Eskişehir The Eskeheşir
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Tunisia - Koutine The Koutine area
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Russia - Novy Land use in the Novy
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Botswana - Boteti The main land use
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Chile - Cauquenes The Cauquenes are
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Status of land degradation, sustain
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Examples of potential SLM technolog
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IV Up-scaling SLM strategies Actual
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Case study of the DESIRE methodolog
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II Identifying, evaluating and sele
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The results showed that the best op
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IV Up-scaling SLM strategies Some r
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Cropland (or grazing land, mixed la
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Explanation pages of case studies:
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Here appears an organogram - if ava
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Pictograms SLM technology Land use
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Logos of partners 282 DESIRE - WOCA
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Desire for Greener Land

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