Messrs: JK Kutuahupira, HD Mouton Agro-ecological Zoning Programme Ministry of Agriculture, Water and Forestry Namibia ABSTRACT .................................................................................................................................... 6 CHAPTER 1: GENERAL INFORMATION ...................................................................................... 7 1.1 Introduction .......................................................................................................................... 7 1.2 The pilot area ....................................................................................................................... 8 1.3 Literature review .................................................................................................................. 9 1.3.1 Preparatory work ............................................................................................................ 9 1.3.2 Desk study ..................................................................................................................... 9 1.3.3 Data recording or capturing ............................................................................................ 9 1.3.4 Fieldwork ..................................................................................................................... 10 1.3.5 Types of observation methods used to describe the soil profiles .................................. 10 1.3.6 Soil classification system used and soil profile descriptions ......................................... 10 1.3.7 Laboratory methods ..................................................................................................... 10 CHAPTER 2: CLIMATIC INFORMATION ..................................................................................... 14 2.1 Introduction ........................................................................................................................ 14 2.2.1 Climate ........................................................................................................................ 14 2.2.2 Precipitation ................................................................................................................. 14 2.2.3 Evaporation .................................................................................................................. 15 2.2.4 Wind ............................................................................................................................ 16 2.2.5 Temperature ................................................................................................................ 16 2.2.6 Agro-ecological zones .................................................................................................. 16 2.2.7 Rock outcrop (R) .......................................................................................................... 18 CHAPTER 3: PHYSIOGRAPHY ................................................................................................... 19 3.1 Topography ........................................................................................................................ 19 3.1.1 Escarpment: Mountainous and hilly area ...................................................................... 19 3.1.2 Namibian central plateau ............................................................................................. 19 3.1.3 Kalahari sand plateau .................................................................................................. 20 3.2 Hydrology ........................................................................................................................... 23 3.3 Geomorphology ................................................................................................................. 23 3.4 Geology or Lithology .......................................................................................................... 24 3.4.1 Damara orogenic phase ............................................................................................... 26 3.4.2 Khomas Highlands ....................................................................................................... 26 3.4.3 Windhoek valley ........................................................................................................... 27 3.4.4 Area south of Windhoek towards Rehoboth ................................................................. 27 3.4.5 Matchless amphibolite belt ........................................................................................... 28 3.4.6 The area between Windhoek and Hosea Kutako International Airport .......................... 28 3.4.7 Auas Mountains ........................................................................................................... 28 3.4.8 Bismarck mountains ..................................................................................................... 28 3.4.9 Hohewarte metamorphic complex ................................................................................ 28 3.4.10 Area from airport to Witvlei ......................................................................................... 29 3.4.11 Kalahari ...................................................................................................................... 29 CHAPTER 4: METHODOLOGIES USED TO CLASSIFY TERRAIN TYPES OR LANDFORMS ... 30 4.1 Methods used to define the landforms................................................................................. 30 4.2 Terrain types ...................................................................................................................... 30 4.3 Percentage level land ......................................................................................................... 32 4.4 Profile type ......................................................................................................................... 33 1 4.5 Local relief unit (elevation) ................................................................................................. 33 4.6 What is a highland or lowlands ........................................................................................... 33 4.7 Method used to calculate the slope gradient ...................................................................... 34 4.8 Drainage patterns............................................................................................................... 34 CHAPTER 5: MAIN LAND MAPPING UNITS AND THEIR MESORELIEF .................................... 36 5.1 Introduction ........................................................................................................................ 36 5.2 Land unit E: Hills and Mountains-Mountainous region (D1; D2; D3; D4 and D5) ................ 38 Land unit E-10: High Hills or Mountains (D5c) areas from Damara Sequence of the Duruchaus-, Kamtsas and Auas formation preferably sedimentary rocks. .............................. 38 Land unit E-20: High hills and mountains (D4c) from Damara Sequence preferably the mica schist as the parent material or bedrock exposed on steep slopes. ........................................ 38 Land unit E-30: Moderate hills (D3c) areas with mica-schist rock outcrops belonging to the Khomas and the Huab formations. ......................................................................................... 39 Land unit E-40: Low hills (D2c) consisting of igneous rocks belonging to the Damara sequence as parent material. ................................................................................................................. 39 Land unit E-50: Very low isolated hills (D1c) areas of Damara sequence consisting of mica- schist and quartz. ................................................................................................................... 40 5.3 Land unit D: Highlands of the central plateau with open high hills and ridges (C1) ............. 41 Land unit D-60: Open high hills of the central plateau (C1c) areas of Damara sequence. ...... 41 Land unit C: Plains with isolated hills and inselberge of the central plateau (B3c and A5c) .... 41 Land unit C-70: Plains with isolated koppies and inselberge (B3c and A5c) areas of metamorphic and sedimentary rocks. .................................................................................... 41 Land unit C-80: Highlands with considerable hills, ridges and inselberge (A4d) comprising of ortho-ampholite, granite and quartz rocks. ............................................................................. 42 Land unit C-90: Highlands with low sand ridges and isolated inselberge (A3b, A3c and A3d). .............................................................................................................. 42 5.4 Land unit A: Flat to nearly level plains covered with deep to very deep Kalahari sands (A1a/ A1d); A2a/ A2d; B1c/ B1d and B2d) ....................................................................................... 43 Land unit A-100: Flat to nearly level plains (A1c/d) on sedimentary rocks .............................. 43 Land unit A-110: Smooth plain with some relief (A2a, A2c and A2d) areas with stunning geological formation from Damara Sequence (conglomerate, quartzite and marble), sedimentary and Gariep formation. ........................................................................................ 44 Land unit A-120: Irregular plains characterised sand ridges and very few drainage line (B1c and B1d) areas Damara sequence of the Khomas formation. ...............................................