Glaciers, Nature, Water, and Local Community in Mount Kenya

In 1929, 17 glaciers were identified on Mount Kenya. Later, the glacier inventory of 2004 reported the presence of only 10 glaciers, which were reduced to only 9 in 2016 as documented in the revised glacier inventory published in 2018. In this study, we confirm the existence of eight glaciers by comparing changes in the surface elevation of digital surface models (DSMs). The models are created based on Pleiades satellite images from February 17, 2016 and on digital images acquired from a Cessna aircraft on August 19, 2018. Although the revised glacier inventory of 2016 included Northey Glacier, we are not able to confirm any change in the surface elevation of this glacier. Therefore, it is likely that Northey Glacier could represent a seasonal snow patch without an ice body. The comparison between the DSMs of 2016 and 2018 shows that the surface area of all eight glaciers had declined, indicating a negative mass balance. The average annual mass balance of the six glaciers is found to be −1.4 m w.e./a. The significantly smaller Darwin (0.0039 km²), Heim (0.0025 km²), and Diamond (0.00034 km²) glaciers might represent disappearing glaciers with stagnant ice, which have transitioned from active glaciers.

The regions surrounding Mount Kenya have both long and short rainy seasons, and the corresponding peak rainfalls occur during April and November, respectively. Rainfall in these two seasons reach their maximum potential in areas centered on the southeastern part of the foothills of Mount Kenya and in the Aberdare Range. The relationships between the onset of these rainy seasons and the inland penetrations of the easterly winds at 700 hPa demonstrated that during the long rainy season, wind penetration from the Indian Ocean occurs along the ridge, extending northwards from the southern hemisphere along the eastern coast. During the short rainy season, wind penetration occurs with the strengthening of easterly winds associated with deepening low pressure in the Congo Basin. The relationship between the location of the convergence and divergence of wind field at 700 hPa and the seasonal march of rainfall around Mount Kenya suggest that the seasonal changes in rainfall are not only a result of north–south movement of the convergence zone with the meridional component of wind, but also a result of east–west movement of the divergence zone with the zonal component of wind.

This study focuses on the shrinkage of glaciers on Mount Kenya (5199 m), which is located in central East Africa. Based on field observations, isotope ratio analyses, groundwater age measurements, and interview surveys, here we have discussed the impact of Mount Kenya’s glacial shrinkage on the water environment and the availability of water resources in the surrounding areas. In the study area, which is located at approximately 2000 m elevation, the level of precipitation is generally low, and therefore, the usage of water for agricultural and household activities depends on river water and spring water from Mount Kenya. The average elevation of the recharge zones of river water used by the residents of this mountainous basin is 4650 m, and that of spring water is 4718 m. It is evinced that water from the glacial zone contributes significantly to river water at the base of the mountain. Furthermore, it takes 40–60 years for glacial meltwater to be discharged at the base of the mountain. The glaciers of Mount Kenya are expected to disappear by 2030, which might have a considerable impact on water resources at the foot of the mountain.

This study evaluated whether the local communities residing in the leeward side of Mount Kenya in East Africa are aware of the on-going glacier changes, and its implications on domestic water supply and livelihoods. The spatial analysis of the glacial changes in Mount Kenya was conducted using medium resolution (30 m × 30 m) Landsat imageries and ArcGIS and ENVI software. The local perception survey on glacial changes, river flow, and livelihood impacts was undertaken through face-to-face interviews with 90 riparian residents along the Naromoru and Likii rivers, which included farmers, pastoralists, and urban residents. The findings demonstrated that Mount Kenya has continuously experienced progressive glacial retreat in the last four decades (1976–2016). The level of public perception on the glacial retreat was similar to the actual trend documented through scientific research. Based on this study, we recommend that both the national and county governments should integrate glacial retreat and its hydrological implications in policy and relevant development and natural resources management plans.

Glacier forelands allow us to trace back the processes of soil development by comparing the cross sections of soils that differ in time that has elapsed since the initiation of their respective development. This study discusses the relationship between soil development process and environmental factors in the glacier forelands of Tyndall glacier on Mount Kenya. The following six moraines were classified in the foreland of Tyndall glacier: moraines of the Lewis stage (Lewis I and II), Tyndall stage (Tyndall I–IV), and Liki III. Subsequently, the age of each moraine was estimated. The soil formation process was examined based on the observations of the soil profile. It was found that the soil layers were composed of aeolian particles, which were supplied from the surrounding bare ground. The speed of soil development fell within the range of 0.03–5 mm/year. Particularly, we identified the trend that soil development speed was higher during the earlier stages of soil development. The development speed at an early soil development stage in Mount Kenya was higher than that in other regions, and it was confirmed that the long-term development speed fell within the range observed in other regions.

Tyndall Glacier on Mount Kenya has retreated notably in recent years due to warming atmosphere, i.e., climate change. It was evinced that the fronts of four pioneering plant species have migrated uphill following the retreating glacier. Specifically, the front of Senecio keniophytum, the first to appear in areas exposed by glacier disappearance, migrated a speed similar to that of the glacial retreat. A permanent plot that was adjacent to the glacier terminus in 1996 exhibited a drastic increase in Senecio keniophytum population and cover in 2011. Near the terminus of the recently disappeared glacier, the population and cover of vegetation increased notably; however, this increasing trend was slower after the passage of 10 years since the disappearance of the glacier. Helichrysum citrispinum, a plant species which was not previously reported near the glacier terminus, was first confirmed in 2009, and its increasing distribution might be a direct result of increasing temperature. With the passage of years after the disappearance of the glacier, gravels become weathered and soil particles become finer. As the humus of the pioneering species accumulates, nutrient rich soil develops. The development of soil is also affected by the number of years elapsed after the disappearance of glacier and by the degree of plant establishment that stabilizes the soil layer.

The vegetation of tropical alpine environments is characterized by giant rosette plants, of which, two species, Senecio keniodendron and Lobelia telekii, were found to have grown on deglaciated terrain below Tyndall Glacier on Mount Kenya. The species are one of the most attractive elements of the landscape, which captures the attention of visiting eco-tourists. Therefore, the plants are of conservation interest, particularly during a period of climate change. In this study, I analyzed the growth dynamics and distribution of the two species. Field surveys were conducted in 2016 and 2018. The rates of mortality and recruitment were found to be closely similar, and therefore, the population numbers were stable. The heights of the surviving plants were found to have increased over the two years. When the heights of Lobelia telekii rosette leaves were >20 cm in 2016, the elongation rates of anthotactic spiral inflorescences tended to increase. The amount of solar radiation affected the distribution of the giant rosette plants, i.e., plants were distributed in areas where total solar radiation levels were high.

Over the past 50 years, local farmers residing at the foot of Mount Kenya have noticed various changes in the water environment. The volume of water in rivers has decreased, which is particularly evinced during the dry season; and rainfall has become irregular. In addition to these changes in the water environment, changes in land use and population growth have also affected the agricultural industries, and eventually caused water shortages. To provide a sustainable water source and avoid conflicts, furrows have been banned, and projects using pipelines to draw and distribute water have been promoted in the upper and intermediate zones of the foothills of the mountain. Furthermore, local farmers have developed various strategies to cope with the problems of water shortages. These include dividing their farmland into different plots and planting different crops, choosing crop varieties that are adapted to dry environments, practicing crop rotation and mixed planting, and building small ponds to store water. Meanwhile, water shortages in the lower foot zone have remained potential sources of conflict.

Local people in the Matengo Highlands of Tanzania took an initiative to harness water resources and constructed a hydro-milling machine, a micro-hydropower generation system, and water supply facilities, which have shown to have great potential. Although such initiatives are important, undertaking the sustainable use of those facilities is not an easy task. This chapter examines the process of constructing them and discusses the various factors that affect their sustainable use and management. The results show that local participation and community-based organizations play significant roles in the construction of hydro-milling machine as well as in its sustainable use and management, which have resulted in scaling up the micro-hydroelectric generation system. In terms of water supply facilities, factors such as leadership and water users’ association functioned as key elements throughout the process. Despite the promise of advancements and considerable potential, however, the case study indicates that continued use of water resources portends conflicts as well as cooperation both within the village and among different villages along the river basin.

In this book, the actual situation of glacier shrinkage of Mount Kenya due to global warming, rainfall and snowfall as inputs to the water resources of Mount Kenya and the surrounding areas are studied and discussed. The study also elucidated the impact of changes in the water environment due to glacier shrinkage on the awareness of the people living at the foot of the mountain, which is an arid region, and the wisdom and measures of the local people to cope with such changes. The relationship between soil formation processes and environmental factors on the shrinking glacier front was analyzed. The advance of plant distribution with the retreat of Tyndall glacier was reviewed, and the growth process and distribution of large rosette plants were discussed. In addition, we discussed examples of water resource management in response to climate change in other parts of East Africa, and the factors that influence their sustainable use and management. In summary, the impact of glacier shrinkage on the natural environment and local communities, particularly on the surrounding ecosystem and water environment, is discussed and the challenges for future research on Mount Kenya are presented.