Peri-urban growth into natural hazard-prone areas: mapping exposure transformation of the built environment in Nairobi and Nyeri, Kenya, from 1948 to today

Abstract

Kenya experiences massive urban growth, also into natural hazard-prone areas, exposing settlements and the natural environment to riverine and pluvial floods and other natural hazards. While Nairobi as the capital and principal city has been extensively analysed regarding urban growth and flood hazard in some central parts, awareness of growing peri-urban areas has not been studied as much. The results are of interest to other locations in Kenya and worldwide, too, since the current research and disaster risk practice focus is still too much on megacities and city centres. Therefore, the study compares urban growth into hazard areas in urban rims of Nairobi and Nyeri, Kenya. A change assessment from 1948 to 2020 is conducted by aerial images, declassified satellite images, and recent data. Urban growth rates are 10- to 26-fold, while growth into flood exposed areas ranges from 2- to 100-fold. This study reveals unused opportunities for expanding existing land-use change analysis back to the 1940s in data-scarce environments.

Spatio-Temporal Analysis on Land Use/Land Cover Change in Banda Aceh: A Preliminary Study of Disaster Resilience

“…This spatiotemporal analysis research is closely related to previous research in Banda Aceh as it can expand and deepen the understanding of urban environmental changes in the region. Previous research has provided a general overview of post-tsunami urban environmental changes and vulnerability in Banda Aceh [6][7][8][9][10][12][13][14]. The results of this spatiotemporal analysis can aid understand in more detail how land use change patterns and building dynamics have evolved from 2004 to 2023.…”

“…As urbanization progresses and environmental systems undergo shifts, understanding the patterns and trends of land use/land cover (LULC) alterations becomes pivotal in shaping sustainable urban development and disaster resilience strategies [6]. Banda Aceh has experienced substantial built environment changes over the years, driven by factors such as population growth and urban expansion.…”