Faculty of Agriculture and Environmental Studies

Permanent URI for this communityhttps://repository.chuka.ac.ke/handle/chuka/419

Browse

Browsing Faculty of Agriculture and Environmental Studies by Author "Abdalrahman Ahmed"

Filter results by typing the first few letters
Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Influence of environmental variables and anthropogenic activities on soda-saline lakes chemistry in northern Tanzania: A remote sensing and GIS approach
    (Heliyon, 2025-01-03) Azaria Stephano Lameck; Brian Rotich; Abdalrahman Ahmed; Harison K. Kipkulei; Peto Akos; Emil Boros
    This study employed Remote Sensing and Geographical Information Systems to explore the in- fluence of environmental factors and human-induced land use/land cover changes on the chemistry of soda-saline lakes in Northern Tanzania. Satellite-based rainfall data were sourced from the Climate Hazards Group Infrared Precipitation with Station (CHIRPS) datasets, and temperature data were obtained from MERRA-2. Monthly precipitation, temperature, and drought conditions in lake watersheds were analyzed from 1981 to 2022, while land use and land cover changes were assessed for 2000, 2014, and 2023. Soil types were acquired from the FAO Digital Soil Map of the World, while geological characteristics were sourced from the US Geological Survey database. The findings revealed that the region’s climate is ideal for enhancing evapotranspiration, leading to mineral precipitation, and altering the chemistry of soda-saline lakes. The Standardized Precipitation Evapotranspiration Index revealed increased drought events in the lake basins since 1987, with prolonged drought occurrence between 2000 and 2017. The results also showed that the region is characterized by a variety of soil types, including ferric acrisols, chromic cambisols, calcic cambisols, entisols, inceptisols, eutric fluvisols, distric nitisols, humic nitisols, mollic andosols, ochric andosols, and pellic vertisols. Furthermore, the region is distinguished by diverse geological processes, from Precambrian-Cambrian to tertiary intrusive, triggered by volcanic and tectonic activity. Land use/land cover changes results indicated dy- namics in the various classes with an overall decrease in areas under water bodies (—39.80 %), forests (—22.57 %) and bareland (—36.18) while agricultural land (111.01 %) built-up areas (434.72 %), shrubs and grasses (72.77 %) increased in area coverage over the 23 years study
  • Thumbnail Image
    Item
    Land use/land cover changes due to gold mining in the Singida region, central Tanzania: environmental and socio‑economic implications
    (Environ Monit Assess, 2025-03-17) Azaria Stephano Lameck; Brian Rotich; Abdalrahman Ahmed; Harison Kipkulei; Silvester Raymond Mnyawi; Kornel Czimber
    This study explored the land use and land cover (LULC) changes (1995–2023) in the gold min- ing hotspots of Mang’onyi, Sambaru, and Londoni in the Singida region of Tanzania. The study integrated remote sensing (RS) to evaluate the LULC transi- tions with social survey assessments (83 respond- ents) to determine the resident’s perceptions of the environmental, social, and economic implications of mining bridging technical data with socio-economic realities. Supervised classification of Landsat images was conducted using the random forest (RF) classifier to generate LULC maps with five classes (bareland, agricultural land, forest, built-up, and shrubs and grasses), followed by an analysis to identify LULC change trends. The results showed an overall increase in agricultural land 168.51 km2 (587.55%), bareland 7.70 km2 (121.45%), and built-up areas 0.55 km2 (134.15%), while forest and shrubs and grasses areas declined by 97.67 km2 (− 72.59%) and 79.09 km2 (− 43.49%), respectively. A social survey assessment revealed residents perceived environmental (defor- estation, biodiversity loss, land degradation, water, air, soil pollution), social (occupational hazards, land use conflicts, negative effects on livelihoods and culture, discrimination, child labor, community displacement), and economic (improved housing, infrastructural development, job creation, economy boost, improved access to services) impacts result- ing from mining activities. Our findings underscore