Browsing by Author "Brian Rotich"

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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
Modeling the impact of climate change on maize (Zea mays L.) production at the county scale in Kenya
(Regional Environmental Change, 2025) Harison K. Kipkulei; Sonoko D. Bellingrath‑Kimura; Marcos Lana; Gohar Ghazaryan; Roland Baatz; Katharina Löhr; Custodio Matavel; Mark K. Boitt; Charles B. Chisanga; Brian Rotich; Stefan Sieber2
Global climate change is projected to disproportionately impact cereal crop yields in developing regions, such as Kenya, due to increased vulnerability and limited adaptation capacity of the population. This study examines the current and projected influence of climate change on maize yields in two major maize-producing counties of Kenya. Utilizing the calibrated and evaluated DSSAT-CERES-Maize model (where DSSAT is Decision Support Systems for Agrotechnology Transfer and CERES stands for Crop and Environment REsource Synthesis) for the H614 maize cultivar, we investigated the projected impact of climate change on maize production with reference to a baseline period (1984–2013). Simulations were conducted for the mid-century period (2041–2070) and end-of-century period (2071–2100) using projected climate data from regional climate models (RCMs) under two Representative Concentration Pathways (RCPs; 4.5 and 8.5) scenarios. Our findings indicate a substantial decline in maize yields, ranging from 7 to 20% for the mid-century period and between 22 and 41% for the end-of-century period, with increased temperature during critical growth phases identified as the primary driver. Spa- tial clustering and hotspot analysis reveal differential climate impacts across the region. In the end-of-century period, both scenarios revealed that the counties will be marked by hotspots and adaptation spots, areas where climate change adaptation should be intensified. The study underscores the urgency for tailored, location-specific adaptation measures such as maize- legume intercropping, drought-resistant crops, soil water conservation and optimum sowing to mitigate future yield losses and adapt maize production to climate change.