Work

Evolution of gully erosion and susceptibility factors in the urban watershed of the Kimemi (Butembo/DR Congo)

Year: 2023

Type: article

Abstract: Gully erosion is one of the most intense landscape degradation mechanisms in areas with varying environmental characteristics. Both natural and anthropogenic factors affect the gullying process. Reliable documentation of these processes in tropical African cities is scarce. This study assesses the gully dynamic and the susceptibility factors leading to gullying in the Kimemi urban watershed in eastern Democratic Republic of Congo (DRC). Data were obtained through a combination of fieldwork and digitization of very high spatial resolution images from Google Earth (from 2011 to 2021). The length, width, and area of large gullies (width ≥ 5 m) were measured for each year of the study. A logistic regression model (LRM) was also used to investigate the influence of both physical and anthropogenic factors on gully susceptibility. The results revealed that the number of gullies has increased from 36 to 61 during the last decade. The gully mean length of 63.9 ± 61.1 m, 129.3 ± 104.9 m, and 174.7 ± 153.8 m were obtained for the years 2011, 2015, and 2021 respectively. The average density of gully network for the study period was 0.12 km/km², while the degraded land is ∼1.3 and ∼1.1 ha/year for 2011–2015 and 2015–2021 for the entire watershed. The significant changes in morphometric parameters (length, width, area) were found only in the bare land and building land uses. A strong and positive relationship between the length (m) and the area (ha) was found. Furthermore, the susceptibility of gullying is significantly influenced by the slope, stream power index (SPI), distance to roads and rivers, land use and land cover (LULC), and normalized difference vegetation index (NDVI). This means the areas located in the bare land and building or close to roads and/or streams are more likely to be gullied. This study shows a rather important influence of urbanization on the evolution and susceptibility of land to gully erosion in the Kimemi watershed. Decision-makers should pay attention to anthropogenic factors in the implementation of land management.

Source: Geography and sustainability

DOI: 10.1016/j.geosus.2023.07.001

Authors: Jonathan Ahadi Mahamba, Gloire Mulondi Kayitoghera, Moïse Kapiri Musubao, Géant Basimine Chuma, Walere Muhindo Sahani

Institutions: Université Catholique du Graben, Université Evangélique en Afrique

Language: English

Topic: Soil erosion and sediment transport

Subfield: Soil Science

Field: Agricultural and Biological Sciences

Domain: Life Sciences

SDGs: Sustainable cities and communities, Life on land, Clean water and sanitation, Climate action

Open Access status: gold

Estimated APC paid: $1,700