Assessment of Biomass Potential for Sustainable Charcoal Production in Kajiado County;towards Informed Policy Decisions

Abstract

Charcoal is the primary source of cooking energy in most African countries, where demand from a growing human population has frequently outstripped the availability of wood from forests and woodlands. Fuelwood and charcoal continue to be important energy sources for the majority of Kenyans, who have relied on them for decades to meet their energy needs. Kajiado County is one of Kenya's low-biomass-productivity rangelands, but it is known as a hotspot and a major supplier of charcoal in the neighbouring counties of Nairobi, Machakos, and Kiambu. An in-depth examination of the charcoal value chain in Kenya reveals that Nairobi accounts for 58% of the greater market share of charcoal, with figures indicating that both fuelwood and charcoal account for 48% of total residential energy demand sourced from Kajiado County. It is therefore critical to determine the sustainability of biomass potential for charcoal production, given the imbalanced harvesting rates and extremely low levels of regeneration caused by high demand and supply. Its specific goals were to evaluate the optimum biomass level for charcoal production, map the patterns/extent of land use cover changes as a result of logging/wood harvesting, and produce charcoal in time sequence. The study addresses the study objectives by utilizing remote sensing (RS) and Geographical Information Systems (GIS) to provide a means to assess land cover and thus the change in the state of the environment and biomass regeneration. When combined with socio-economic data, the demand and sources were evaluated, providing links and data to biomass and forest resource management planning. To accomplish these goals, a satellite imagery analysis provided spatial-temporal data in time series that were ground-sampled using a global positioning system to validate the findings. Landsat TM and Sentinel 2 images were analyzed spatially over 30 years at 10-year intervals between 1990 and 2019 to determine land cover changes, as well as NDVI and rainfall patterns using the NOAA/AVHRR over the same period. In-situ observation, household questionnaires and semi-structured expert interviews, literature review revealed the significance of charcoal production to local livelihoods and environment. Field interviews showed low awareness programs as well as absorption of appropriate technologies that could improve harvesting and charcoal production to minimize biomass wastage. The study findings indicated the major sources of wood for charcoal production are steadily decreasing. Forest cover that included woody biomass decreased by 60,455.25 Ha (23%) to 49,188.4 Ha (18.8%) in 2019. This was converted into cropland that saw an increase from 18,552.06 Ha (14.8%) in 1990 to 53,886.3 Ha(43.2%) in 2019 in the same period. This is change is attributed to the increased demand for fuelwood and charcoal combined with unsustainable harvesting of wood biomass due to the rapid increase and growth of the human population. The study revealed that the continued harvesting of charcoal is unsustainable due to predominant wood harvesting and inefficient charcoal production technologies. The resulting land cover change impacts have negatively affected forests and woodlands thus the future wood-energy supply sources due to slow regeneration rates emanating from high harvest rates. The charcoal producers must expand the use of charcoal with high conversion rates of biomass and low gas emissions to increase sustainability. The study contributes to the studies of land cover change and sustainable development in Kenya. It scrutinizes the land use and land cover change (LULCC) and deforestation; impacts of charcoal production on forest ecosystem services and biomass.