Land Use and Land Cover Change in the Coastal Area of Watamu Mida Creek, Kenya

Watamu Mida creek coastal areas, mainly the shoreline, the mangroves and the general environment have been changing due to the impact of land use change, shoreline erosion, human population pressure and the expansion of tourism sector. This research assesses the impact of land use change on mangrove dynamics and shoreline erosion as well as the main driving factors that cause these changes in Watamu Midacreek. This study uses old aerial photographs (1969 and 1989), current high resolution satellite images World view (2010) and ground truthing in combination with information from the local community to analyze the impact of change in land use from 1969-2010. Land use and cover types were visually interpreted, digitized and delineated using aerial photographs of 1969, 1989 and 2010 satellite images in ArcGIS.9.3.1 and ERDAS IMAGINE 2014 software. The results of the land use change between 1969 and 1989 showed a decline of scrub land, miscellaneous coastal vegetation, coastal bush, thicket with trees and mangroves, whereas new types of land use which emerged during this period were town and barren land. The greatest land use change rate observed between 1969 and 1989 was in miscellaneous coastal vegetation at 2.5%, while coastal bush experienced a significant negative change rate of 6.5%. The main land use changes observed between 1989 and 2010 were increasing coastal bush, an expansion of town and urban areas, hotels and private holiday houses. Encroachments into the mangrove forest have been observed both by local people and foreign private holiday house owners. The change in land use had an impact on shoreline changes as well. Areas mainly covered by old trees, and coastal bushes which protected the shoreline from erosion currently have been converted into very big hotels and several private holiday house complexes. The main drivers of land use change were human population growth and policy (through weakness of law enforcement). Policies and regulations which are not currently implemented need to be updated based on the current pressure-state situation, and there should be strong law enforcement and strict regulation to control any unplanned developments along the coast and in the neighboring hinterland.

Assessment of Mangrove Covers Change and Biomass in Mida creek, Kenya

This study uses old aerial photographs, current high resolution satellite images and ground truthing to analyze the patterns and dynamics of Mida Creek mangrove forest changes over 41 years from 1969-2010. A non-distractive method was used to collect data on 25 sample plots and 934 trees were measured to estimate the above ground biomass and carbon stock of the forest. General published allometric equations with variables of Diameter at Breast Height (DBH) and wood density (ρ) which were species specific were used to estimate above ground biomass. A decline in mangrove cover (16%) took place between 1969 and 1989 and between 1989 and 2010 an increment was observed in mangrove cover (1452.5 ha in 1989 to 1655.7 ha in 2010). Signs of degradation within the mangrove forest were observed in 2010 in which the degraded land covered 8.8 ha. The total above ground biomass and carbon estimated on the 25 plots was 296.14 ton·ha-1 and 148.07 ton·ha-1 respectively. Mida Creek mangrove forest is largely dominated by the presence of Rhizophora mucronata and Ceriop tagal and the regeneration of these two species is very high. If the present dominance of the two species continues it will affect the species composition of the current mangrove forest. This study recommends a better management plan for the mangrove forest through increasing involvement of the surrounding communities. Furthermore, there should be a way to control selective and illegal cutting of mangroves and promote other species of trees for domestic and commercial use to reduce the high dependency on the use of mangroves for construction purposes.