Assessment of Hydrological Water Balance in Lower Nzoia Sub-catchment: Towards Improved Water Governance in Kenya .

Abstract

This research reinforces that water availability in a given area can be linked to Land Use Land Cover (LULC) changes and water balance. Having operational adaptive capacity of water governance systems on the other hand can enable community resilience in case of changing environment and climate. In this study, the rsearcher was guided by the following objectives: (i) Land Use Land Cover and population changes analysis; (ii) hydrological water balance assessment; and (iii) discussion on the institutions adaptive capacity constraints. Analysis of the changes in LULC in Lower Nzoia Sub- Catchment (LNSC) for the last thirty years was done using modern technologies such as Remote Sensing and Geographical Information System. Image differencing approach was adopted in carrying out change detection using the from-to analysis. In order to find out correctly classified LULC, accuracy assessment was done using reference points. On the other hand, the Soil and Water Assessment Tool was used in estimating hydrological water balance of 2018 LULC as a way of understanding the hydrological characteristics of the area. The SWAT model for this study embraced use of hybrid data from locally available data and satellite data extracted from Global Weather Data for SWAT. However, combining these two sets of data may have influenced the results attained. Water balance and water yield are useful in determining water availability which in return is important when discussing social and institutional adaptive capacity aspects of water governance. The findings of this study shows that there is increasing urban/ built-up area as well as population for the last thirty years while there is no or limited focus on adaptive capacity aspects. If these trends continue while adaptive capacity remain to be business as usual, the communities in LNSC might not be able to cope in case of increased water availability or lack of it hence hindering community resilience. Therefore, one of the possible solutions is prioritising integration of supply-side management, demand- side management and adaptive capacity in water sector from local level to national level. The findings of this study can be beneficial to individuals and groups involved in planning and management of water resources as well as civil societies that implement water related interventions. The geographical extent of Lower Nzoia Sub- Catchment is 534.24km².