Climate Change Action Toolkit for Groundwater Use in Agricultural Production: Case Study of Lwanda, Bungoma County

Abstract

Groundwater is an alternative fresh water source for domestic, industrial and agricultural production. Groundwater use can sustain agricultural production through irrigation during prolonged dry season to increase crop production and vegetation cover that form carbon sink. The overall objective of the study was to develop a Climate Change Action Toolkit (CCAT) for groundwater use in agricultural production to minimize climate change impacts of prolonged dry season experienced in Bungoma County. The research study was conducted in Lwanda village with field experimentation on thirty shallow wells. Depth Aquifer Recharge and Transmissivity (DART) index quantitative method and United Nations Development Programme Policy Framework (APF) methodologies were applied concurrently as a Trans-Disciplinary Approach to develop a Climate Change Action Toolkit involving various stakeholders. This is because smallholder farmers have their unique capabilities and Climate Change effects on livelihoods are not uniform. The results revealed that rainfall was directly related with DART index, Groundwater volume, Water Rest Level, Storativity, Transmissivity and Rainfall recharge. Rainfall was indirectly related with change in water depth and groundwater use. There was no relationship between the age of shallow wells and rainfall. A monthly positive DART index was observed in the month of April, May, June, September and October indicating the possibility of enhanced groundwater harvesting for agricultural production. The negative DART index was experienced in the months of January, February, March, July, August, November and December. DART indices ranged between -8.40 and 2.50 with higher values representing more resilience to the Climate Change impacts and vice versa. There were two DART Index Thresholds of -8.40 and -4.80 respectively that coincided with the onset of long and short rainfall seasons. The Mann-Kendall trend analysis values indicated an upward trend for rainfall, groundwater recharge, storativity, volume, transmissivity, groundwater use and number of shallow wells drying up but a decreasing trend for groundwater DART index and a monotonic trend in Water Rest Level. The increasing trend of shallow wells drying up indicates the vulnerability of groundwater to support agricultural production. There was a significant difference in DART index, depth of shallow wells, potential groundwater uses and Storativity but there was no significant difference in rainfall and other groundwater variables. Shallow wells were dug manually with depth of between 6.95 and 13.05 metres. The shallow wells that dried up during prolonged dry season between of four months accounted for 53 percent. A single shallow well served between 1 and 12 households with one hundred and sixty-seven households benefiting from 30 shallow wells. The low farmers’ adaptive capacity was due to lack of structured farmer training and water user’s association, poverty, weak institution linkages and inadequate legislations. The advanced age of farmers, remain a hindrance that cause them not to trust various information sources for transfer of superior technologies. Non-Governmental Organizations and radio were the most popular sources of agricultural and weather information respectively. There was no formal platform for Indigenous Knowledge integration to climate change adaptation. Implementing an appropriate action plan that incorporates broad perspectives of the vulnerability features identified by stakeholders improves ownership by groundwater users and adaptation to Climate change. The adoption of a CCAT-DART is capable of reducing GHG emissions by 18 % of soil carbon and 8810 tons of CO2 per acre per farmer annually. Piloting of groundwater use technologies and strategies suggested is necessary to improve information dissemination to enhance adoption and adaptive capacity. The DART Index Thresholds are risk management indicators against negative climate change impacts for issuance of agricultural finance insurance cover. There is need for further research study on soil erosion and rainfall recharge to improve knowledge on ground water recharge and sedimentation.