A New Approach to Soil and Water Conservation in Ethiopia
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ESAPP Sustainable Land Management – A New Approach to Soil and Water | downloaded: 8.5.2016 Conservation in Ethiopia Mitiku Haile Karl Herweg Brigitta Stillhardt Land Resources Management and Environmental Protection Department Mekelle University, Ethiopia, and Centre for Development and Environment (CDE), Swiss National Centre of Competence in Research (NCCR) North-South University of Bern, Switzerland 2006 https://doi.org/10.7892/boris.19217 source: ESAPP Sustainable Land Management – A New Approach to Soil and Water Conservation in Ethiopia Sustainable Land Management – A New Approach to Soil and Water Conservation in Ethiopia Mitiku Haile Karl Herweg Brigitta Stillhardt Land Resources Management and Environmental Protection Department Mekelle University, Ethiopia, and Swiss Centre for Development and Environment, National Centre of Competence in Research (NCCR) North-South University of Bern, Switzerland 2006 Citation: Mitiku, H., Herweg, K., Stillhardt, B., 2006 Sustainable Land Management – A New Approach to Soil and Water Conservation in Ethiopia. Mekelle, Ethiopia: Land Resources Management and Environmental Protection Department, Mekelle University; Bern, Switzerland: Centre for Development and Environment (CDE), University of Bern, and Swiss National Centre of Competence in Research (NCCR) North-South. 269 pp. This publication was prepared with support from: Eastern and Southern Africa Partnership Programme (ESAPP) and Swiss National Centre of Competence in Research (NCCR) North-South, funded by the Swiss Agency for Development and Cooperation (SDC) and the Swiss National Science Foundation (SNSF) Land Resources Management and Environmental Protection Department, Mekelle University, Ethiopia Copyright: Mekelle University P.O.Box 231 Mekelle, Ethiopia Tel: +251 (0)4 409 228 Fax: +251 (0)4 409 304 Mail: [email protected] Layout: Simone Kummer Centre for Development and Environment (CDE) University of Bern Cover Photos: Frontcover: Karl Herweg Backcover: Martin Moll Graphics, Tables and Photos: Karl Herweg and Brigitta Stillhardt Centre for Development and Environment (CDE) University of Bern Copies of this report can be obtained from: Mekelle University P.O.Box 231 Mekelle, Ethiopia Tel: +251 (0)4 409 228 Fax: +251 (0)4 409 304 Mail: [email protected] ISBN 3-906151-92-1 Contents Foreword 13 1 Approaches and Concepts 15 1.1 Introduction 15 1.2 Elements of the new approach 16 1.3 Land degradation problems and causes 19 1.4 Approaches in soil and water conservation extension 24 1.4.1 Approaches in the development of soil and water conservation technologies 26 1.4.2 Approaches to evaluation methodologies in soil and water conservation 26 1.4.3 Approaches in soil and water conservation training and research 26 2 Soil Degradation with a Focus on Soil Erosion 31 2.1 Soil functions 31 2.2 Global aspects of soil degradation 32 2.3 Types of soil degradation – a brief brush-up 36 2.4 Soil erosion by water – a specific form of soil degradation 39 2.4.1 Soil erosion processes and features 40 2.4.2 Direct factors of influence on soil erosion 45 2.5 Questions and issues for debate 50 3 Soil Erosion Monitoring Methodology 51 3.1 Concept and methodology of the Soil Conservation Research Program of Ethiopia 51 3.1.1 Altitudinal zonation and agroecological belts 52 3.1.2 Traditional classification of altitudinal belts 53 3.1.3 Agroecology and agroclimatology 54 3.2 SCRP research methodology 55 3.3 Levels of soil erosion measurement – an example 58 3.4 Management concept and interpretation of SCRP data 60 3.5 Questions and issues for debate 64 5 4 Average Soil Erosion Patterns under Different Agro-Climatic Conditions 65 4.1 Temporal resolution I: mean annual data 67 4.1.1 General interpretation 67 4.1.2 Site-specific interpretation 70 4.2 Temporal resolution II: mean monthly data 74 4.3 Spatial differentiation I: the influence of plot length and steepness on erosion 76 4.4 Questions and issues for debate 78 5 Extreme Soil Erosion Patterns 79 5.1 Temporal resolution III: the irregularity of rainstorm periods 79 5.2 Spatial differentiation II: hot spots of erosion 81 5.2.1 Assessment of current erosion damage (ACED) 83 5.2.2 ACED case studies in selected research sites 88 5.2.3 Linking ACED with test plot measurements 93 5.3 Questions and issues for debate 96 6 Classification of SWC 97 6.1 SWC – scattered knowledge 97 6.1.1 Efficient management of existing knowledge 97 6.1.2 WOCAT – making local experience available at the global level 97 6.2 The WOCAT classification of SWC technologies 98 6.3 SWC – principles of functioning 102 6.4 Questions and issues for debate 106 7 Development of SWC Technologies 107 7.1 Indigenous Ethiopian SWC measures 107 7.2 Proper planning of SWC 108 7.3 Structural (mechanical) soil and water conservation 110 7.4 Agronomic and vegetative SWC measures 125 7.5 Land use changes 130 7.6 SWC on non-agricultural land 130 7.7 Wind erosion control measures 131 7.8 Salinity control measures 131 7.9 Questions and issues for debate 132 6 8 Assessment of Soil and Water Conservation 133 8.1 About assessment, criteria and personal perceptions 133 8.2 Example I: SWC measures under semi-arid conditions 134 8.3 Example II: on- and off-site effects of tied ridges 136 8.4 Example III: comprehensive assessment of selected soil and water conservation measures 137 8.4.1 Methodology 138 8.4.2 Results 140 8.4.3 The ecological dimension: soil loss and runoff 145 8.4.4 The socio-economic dimension: crop production, viability 147 and acceptability 8.4.5 The technical dimension: ill-design and malfunctioning 152 8.4.6 Conclusions 153 8.5 A tool to assess effects and impacts of SWC 157 8.6 Questions and issues for debate 161 9 Sustainable Land Management as a New Approach 163 9.1 Attempts to describe sustainability 163 9.1.1 Definitions of sustainability 163 9.1.2 Definitions of sustainable agricultural systems 163 9.2 Approaching sustainability through unsustainability 166 9.3 Sustainability dimensions 171 9.4 The need for a multi-level-multi-stakeholder approach 173 9.5 The role of science in SLM 174 9.6 Developing an actor-oriented perspective 175 9.6.1 Peasant-oriented perspective 176 9.6.2 Sustainable livelihoods approach 178 9.7 Questions and issues for debate 179 10 Indigenous Knowledge as an Entry Point to Participatory Technology Development 181 10.1 What is indigenous knowledge? – A definition by the World Bank 181 10.2. Indigenous soil and water conservation 184 10.3 Case studies 191 10.3.1 Konso 191 10.3.2 Irob: dams to trap silt and water 192 10.4 Ethnoecology and ethnopedology 193 10.4.1 The physical dimension of ethnopedology 195 10.4.2 The perceptual dimension of ethnopedology 195 10.5 Questions and issues for debate 197 7 11 Participatory Technology Development 199 11.1 Historical development 199 11.2 Principles of PTD 203 11.3 Major clusters or phases of PTD activities 204 11.3.1 Favorable conditions for PTD 205 11.3.2 Challenges and limitations 206 11.4 From participatory to transdisciplinary research 207 11.5 Questions and issues for debate 207 12 Impact Monitoring and Assessment 209 12.1 Clarification of terminology 209 12.2 Six steps of impact monitoring and assessment 211 12.2.1 Involvement of stakeholders and information management 211 12.2.2 Problem analysis and identification of core issues 212 12.2.3 Formulation of impact hypotheses 213 12.2.4 Selection of impact indicators 218 12.2.5 Development and application of impact monitoring methods 226 12.2.6 Impact assessment 233 12.3 Questions and issues for debate 238 13 Decision Support System for Soil Erosion / Soil and Water Conservation 239 13.1 Overview 240 13.2 Detailed consideration of soil erosion and SWC 243 13.2.1 Climatic considerations in SWC 243 13.2.2 Critical locations 244 13.2.3 Timing of SWC 246 13.2.4 The role of vegetative-agronomic SWC 246 13.2.5 Impacts of selected structural SWC measures 247 13.2.6 Spacing of SWC measures 247 13.2.7 Planning of SWC interventions 247 13.2.8 Impact assessment of SWC 248 13.3 Questions and issues for debate 248 References 249 Annex 1: Brief Description of the Research Sites in Ethiopia 271 Annex 2: Impact Monitoring and Assessment 295 8 Photos Photo 2.1: Soil color as an indicator of erosion 43 Photo 2.2: Soil surface levels 44 Photo 2.3: Gully erosion 44 Photo 2.4: Badlands 45 Photo 5.1: Runon, rill erosion and accumulation 85 Photo 5.2: Footpath and soil erosion 86 Photo 5.3: Roadside gully 86 Photo 7.1: Integrated soil and water conservation structures 113 Photo 7.2: Two examples of stone terraces in a semi-arid environment 115 Photo 7.3: Silted up tied ridges after water is infiltrated. 119 Photo 7.4: Water harvesting in a micro catchment in Niger 120 Photo 8.1: An example of failure of SWC structures in Kembata, Ethiopia 152 Photo 8.2: Ill-designed SWC scheme – lack of skills and experience 153 Photo 10.1: Selective removal of SWC structures 186 Photo 10.2: Photo-monitoring: slope treated with SWC measures 187 Photo 10.3: Photo-monitoring: modified SWC measures 187 9 Figures Figure 2.1: Soil functions 31 Figure 2.2: Global degradation of crop and pasture lands 33 Figure 2.3: Major processes and causes of human induced soil degradation 34 Figure 2.4: On-site and off-site effects of soil erosion 35 Figure 2.5: Natural erosion and accelerated soil erosion 40 Figure 2.6: Erosivity and erodibility.