Baseline Report Yala and Nzoia River Basins
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| Baseline Report
Western Kenya Integrated Ecosystem Management Project Findings from the Baseline Surveys Compiled by: Anja Boye Louis Verchot Robert Zomer With technical support form: Luka AnehoAnjeho Joash Mango Donald Agwa Odhiambo Meshack Nyabenge Florence
International Centre for Research in Agorforestry Nairobi, Kenya 5 March 2008 
Table of Contents 1.Introduction 4 Aim and objectives 4 Introduction to the Yala river basin 4 2.Baseline data collection 5 2.1 Sampling design 5 2.2Sampling methods 5 2.2.1Socio economic sampling methods 5 2.2.2Biophysical sampling methods 6 3.Lower Yala 9 3.1Biophysical baseline data summary 9 3.1.1Topography 9 3.1.2Soil texture and soil depth restrictions 11 3.1.3Vegetation and land use 12 3.1.4Soil erosion and conservation measures 14 3.2Socio economic baseline data summary 16 3.2.1Household parameters 16 3.2.2Land use and livestock 17 3.2.3Major constraints at farm level 18 3.2.4Soil and water conservation 19 3.2.5Trees & Agroforestry 19 3.2.6Household energy supply 20 3.2.7Trainings and group membership 20 3.3Management Recommendations 21 4.Middle Yala 25 4.1Bio physical baseline data summary 26 4.1.1Topography 26 4.1.2Soil texture and soil depth restriction 27 4.1.4Soil erosion and conservation measures 29 4.2Socio economic baseline data summary 31 4.2.1Household parameters 31 4.2.2Land use and livestock 32 4.2.4Soil and water conservation 34 4.2.5Trees and Agroforestry 34 4.2.6 Household energy supply 35 4.2.7 Training and group membership 35 4.3Management recommendations 36 5Upper Yala 41 5.2Biophysical baseline data summary 42 5.2.1Topography 42 5.2.2Soil texture and soil depth restrictions 43 5.2.3Vegetation and land use 43 5.2.4Soil erosion and conservation measures 46 5.3Socio economic baseline data summary 47 5.2.1.Household parameters 47 5.2.2.Land use and livestock 48 5.2.3Major constraints at farm level 48 5.2.4Soil and water conservation 49 5.2.5Trees & Agroforestry 49 5.2.6Household energy supply 50 5.2.7Trainings and group membership 51 5.3Management Recommendations 51 6.Lower Nzoia 55 6.1Biphysical baseline data summary 56 6.1.1Topography 56 6.1.2Soil texture and soil depth restrictions 57 6.1.3Vegetation and land use 58 6.1.4Soil erosion and conservation measures 60 6.2Socio economic baseline data summary 62 6.2.1Household parameters 62 6.2.2Land use and livestock 63 6.2.3Major constraints at farm level 64 6.2.4Soil and water conservation 65 6.2.5Trees & Agroforestry 65 6.2.6Household energy supply 66 6.2.7Trainings and group membership 67 6.3Management Recommendations 67 7Conclusion 71
The first aim of the WKIEMP baseline reports are to synthesize a quantitative description of the baseline project situation along the ecological and socioeconomic dimensions that are relevant for project implementation. In this context, flexible strategies for selecting priority intervention areas and households at the landscape/population scale are proposed. The second aim is to lay a foundation for change detection that considers spatial variability explicitly.
The Yala River Basin covers an area of 3,351 km2 and the Yala River is one of the main Kenyan rivers draining into Lake Victoria. Average discharge is 27.4 m3/s, with a total N content of 1000 tonnes per year and total P content of 102 tonnes per year . T  Map of the Yala River Basin showing the 3 blocks he Western Kenyan Integrated Management Project (WKIEMP) has identified three main areas in the Yala River Basin in which activities will take place. These focus areas (or “blocks”) have been identified from ground surveys and satellite images and have been placed to represent the basin in terms of elevation, slope, rainfall regimes and land use: the Lower Yala block is located in an area with high population density and moderate slopes; the Middle Yala block further upslope characterized by higher elevation, moderate to steep slopes and less erratic rainfall and finally, the Upper Yala block characterized by larger farms and higher elevation. Baseline data was collected for socioeconomic and biophysical parameters. Before commencing the baseline data collection, the local administration was informed of the project and a series of meeting arranged in each of the sub-locations where sampling iswas to take place. KARI and ICRAF jointly hold these meetings, where the overall objectives of the project were outlined and discussed.
The baseline data collection is built around the use of blocks of 10 10 km in size. The basic sampling unit is called a cluster. In each block, 16 centre points are generated from which 10 sampling plots that constitute the cluser are generated. Hence, in each block the sampling size is 160 plots (see map in section 3.1). The centre point of each cluster is randomly placed within each block. The sampling plots are then randomized around each cluster center point, resulting in a spatially stratified sampling design. This sampling design ensures proportional sampling within each block and minimizes local biases. The randomization procedures are done using either customized programs or scripts or a special Microsoft Excel spreadsheet that has been prepared for this purpose. Using these tools enables easy up-load of plot coordinates to GPS units, which are then used to navigate from sampling plot to sampling plot in the baseline data collection exercise. For more detailed information about the randomization procedure see Annex 1, p.4 or the Biophysical and Socioeconomic Monitoring and Evaluation Plan. |