DIRECTORATE OF ENVIRONMENTAL AFFAIRS MINISTRY OF ENVIRONMENT AND TOURISM NNNAAATTTUUURRRAAALLL RRREEESSSOOOUUURRRCCCEEE MMMAAAPPPPPPIIINNNGGG OOOFFF TTTHHHEEE KKKAAAVVVAAANNNGGGOOO RRREEEGGGIIIOOONNN FINAL REPORT P. O. BOX 20690 WINDHOEK TEL: +264 (0) 61 220 400 FAX: +264 (0) 61 230 934 CONSULTANTS IN THE EARTH SCIENCES e-mail: [email protected] In association with: GISL (UK) LIMITED Dr A. Burke E. B. Simmonds December 2000 TABLE OF CONTENTS 1 INTRODUCTION .......................................................................................1 1.1 Project Background................................................................................................................1 1.2 Mapping objectives.................................................................................................................1 1.2.1 Terms of Reference for the Natural Resource Mapping of Kavango Region...................1 1.2.2 Mapping Specifications and Expected Outputs ................................................................1 1.2.3 Interpretation of ToR Requirements .................................................................................1 1.3 Conceptual Design ..................................................................................................................2 1.3.1 The Land Systems Approach............................................................................................3 1.3.2 Summary of Proposed Mapping Protocol.........................................................................3 2 METHODOLOGY ......................................................................................4 2.1 Image Processing and Remote Sensing Procedures.............................................................4 2.1.1 Expected Outputs..............................................................................................................4 2.1.2 Actual Outputs..................................................................................................................5 2.1.2.1 Steps 1 - 5 .....................................................................................................................5 2.1.2.2 Reconnaissance Field Survey .......................................................................................5 2.2 Revised Methodology .............................................................................................................6 2.2.1 Preparatory Work..............................................................................................................6 2.2.1.1 Land Region Mapping ..................................................................................................6 2.2.1.2 Secondary Data Review................................................................................................6 2.2.2 Field Survey......................................................................................................................6 2.2.2.1 Vegetation Survey .........................................................................................................6 2.2.2.2 Soil Survey ....................................................................................................................7 2.2.3 Data Analysis and Interpretation ......................................................................................7 2.2.3.1 Land Elements ..............................................................................................................7 2.2.3.2 Vegetation Analysis and Initial Interpretation..............................................................7 2.2.3.3 Soil Analysis .................................................................................................................7 2.2.4 Verification of Land System Boundaries..........................................................................8 2.2.5 Soil Classification and Boundary Mapping ......................................................................8 2.2.6 Land Systems Map Production.........................................................................................8 2.2.7 Final Data Analysis and Mapping of Vegetation Types ...................................................9 2.2.7.1 Data Structure ..............................................................................................................9 2.3 Satellite Data Discrepancies and Mapped Outputs ...........................................................10 2.3.1 The Vegetation Map .......................................................................................................10 2.3.1.1 Lack of Useful Satellite Image Map Base...................................................................10 2.3.2 The Soils Map.................................................................................................................10 2.3.2.1 Manual Mapping ........................................................................................................10 2.4 Vegetation and Soil Unit Descriptions ................................................................................11 2.4.1 Specialist Reports ...........................................................................................................11 3 CLIMATIC AND EVOLUTIONARY SETTING .........................................12 3.1 Climatic Zones ......................................................................................................................12 3.2 Agro-ecological Zones ..........................................................................................................12 i 3.3 Geological and Geomorphological Overview .....................................................................13 3.3.1 Topography and Regional Drainage Characteristics ......................................................13 3.3.2 Landforms and Geological Context................................................................................13 4 SOILS ......................................................................................................15 4.1 Soil Phases .............................................................................................................................15 4.1.1 Phreatic Phase.................................................................................................................15 4.1.2 Yermic Phase..................................................................................................................15 4.1.3 Fragipan Phase................................................................................................................16 4.1.4 Duripan Phase.................................................................................................................16 4.1.5 Rudic Phase ....................................................................................................................16 4.1.6 Petrocalcic Phase ............................................................................................................16 4.2 Soil Classification Summary................................................................................................17 4.2.1 Qualification of Soil Horizons by Charcoal Accumulation ............................................17 4.2.2 Aridic Moisture Regime .................................................................................................17 4.2.3 CEC Values and the Determination of Soil Fertility ......................................................18 4.3 Explanatory Legend to the Reconnaissance Soil Map of Kavango Region .....................19 4.3.1 Soils Conditioned by Parent Material.............................................................................19 4.3.1.1 Arenosols: Soils Developed in Sands..........................................................................19 4.3.2 Soils Conditioned by Limited Leaching .........................................................................20 4.3.2.1 Solonetz: Sodic Soils...................................................................................................20 4.3.2.2 Calcisols: Soils with a Calcium Carbonate Accumulation.........................................21 4.3.3 Soils Conditioned by Relief............................................................................................22 4.3.3.1 Fluvisols: Soils of Alluvial Lowlands .........................................................................22 4.3.4 Soils Conditioned by Human Influence..........................................................................22 4.3.4.1 Anthrosols...................................................................................................................22 4.4 Soil Unit Subdivisions...........................................................................................................23 5 LAND SYSTEMS AND ASSOCIATED VEGETATION TYPES...............25 5.1 Land Region 1 Western Stabilised Dunes...........................................................................25 5.1.1 Vegetation Types Associated with Land Systems of the Western Stabilised Dunes......26 5.1.1.1 Baikiaea plurijuga – Schinziophyton rantanenii Woodland on Stabilised Dunes ......26 5.1.1.2 Burkea africana – Bauhinia petersiana Woodland and Shrubland on Dune Fringes 27 5.2 Land Region 2 Karst Pediplain ...........................................................................................28 5.2.1 Vegetation Types Associated with Land Systems of the Karst Pediplain ......................28 5.2.1.1 Acacia erioloba – Terminalia sericea Shrubland on Pediplain..................................28