Observed and projected changes in urbanization and nature conservation in a typical fast growing city of Ethiopia, Jimma

Abstract

Urbanization threatens biodiversity mostly in developing nations where rural-urban migration is high and urban planning is poor to consider nature conservation. Lacks of adequate information on how to integrate urban expansion and nature conservaion is aggravating environmental problems and making mitigatory actions di cult. Here we quanti ed how Jimma city, a typical fast growing city in Ethiopia, expanded over the past 35 years, predicted change for the next 50 years and mapped priority areas for conservation. Landsat satellite images of 1985 and 2020 were used to map major land cover types and to quantify temporal changes during this period. We used Markov chain model to predict changes over the next 50 years and GIS-based multi-criteriato identify conservation priority areas. Our nding showed adverse effect of urban expansion on the natural habitats. Over the past three decades, built-up areas were expanded by sevenfold (721%; 2227 ha) while croplands were expanded by 34% (4155 ha). In contrast, a substantial shrinking noticed to the natural habitats: forest cover declined by 39% (5209 ha), grass land by 20% (655 ha) and wetland by 28% (638 ha). Our projection of the current trend to the next 50 years indicated the built-up areas may further increase by fourfold (436%; 13565 ha). However, open water, wetland, natural forest and cropland are predicted to decline by 81% (120 ha), 40% (660 ha), 42% (3455 ha) and 55% (8848 ha), respectively. Under current rate of population growth and rural-urban migrations, urban expansion is inevitable. Our study indicated the importance of delineating at least 9040 ha (28%) of the land within city administration which we categorized as high and very high priority areas for conservation of biodiversity. To build inclusive, safe, resilient, and sustainable cities, the urban administrations in developing nations are in need of sound policy, strategies, and planning that support the integration of urban development and nature conservation especially maintaining the existing key biodiversity areas.