5 research outputs found
Influence of environmental variables and anthropogenic activities on soda-saline lakes chemistry in northern Tanzania: a remote sensing and GIS approach
No full textThis study employed Remote Sensing and Geographical Information Systems to explore the influence 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 dynamics 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 period (2000–2023). This study underscores the complex interplay between environmental variables and human activities in shaping the chemistry of soda-saline lakes
Vegetation Dynamics and Climate Variability in Conflict Zones: A Case Study of Sortony Internally Displaced Camp, Darfur, Sudan
No full textUnderstanding vegetation dynamics and climate variability in the vicinity of Internally Displaced Person (IDP) camps is critical due to the high dependency of displaced populations on local natural resources. This study investigates vegetation cover changes and long-term climate variability around the Sortony IDP camp in Darfur, Sudan, using satellite and climate data spanning 1980 to 2024. High-resolution imagery from PlanetScope and Sentinel–2 Level 2A was used to assess vegetation cover changes from 2015 to 2024, while precipitation, temperature, and drought trends were analyzed over 44 years (1980–2024). Vegetation changes were quantified using the Normalized Difference Vegetation Index (NDVI), and drought conditions were assessed through the Standardized Precipitation Evapotranspiration Index (SPEI) at 6-, 9-, and 12-month timescales. Future precipitation predictions were modeled using the Autoregressive Integrated Moving Average (ARIMA) model. The results revealed a substantial increase in vegetative cover: the dense vegetation class increased by 3.50%, moderate vegetation by 17.33%, and low vegetation by 30.22%. In contrast, sparse and non-vegetated areas declined by 4.55% and 46.51%, respectively. The SPEI analysis indicated a marked reduction in drought frequency and severity after 2015, following a period of prolonged drought from 2000 to 2014. Forecasts suggest continued increases in rainfall through 2034, which may further support vegetation regrowth. These findings underscore the complex interplay between climatic factors and human activity in conflict-affected landscapes. The observed vegetation recovery highlights the region’s potential for ecological resilience, reinforcing the urgent need for sustainable land-use planning and climate-adaptive management strategies in humanitarian and post-conflict settings such as Darfur
Effect of Microwave Radiation on Regeneration of a Granulated Micelle–Clay Complex after Adsorption of Bacteria
No full textGranulated micelle–clay complexes including the organic cation octadecyltrimethylammonium (ODTMA) were shown to be efficient in removal of total bacteria count (TBC) from water. Microwave (MW) heating of granules to restore bacterial removal was investigated. Drying of granules by MW required 20-fold less energy than by conventional heating. When water content of granules approached 10%, or less, their heating period by MW had to be below 1 min, e.g., 30 s, and less, in order to avoid ignition and irreversible structural changes. Structural and thermal properties of MW heated samples were studied by FT-IR spectra and thermo gravimetric analyses (TGA). Inactivation of bacteria in water was more efficient by MW than by conventional oven, or by electric plate. For elimination of bacteria from water, MW heating was at least five-fold more efficient than by conventional heating. The results have established an adequate regeneration procedure by MW heating at durations depending on the remaining percentage of water associated with the granules. Tests of first and second regenerations by MW heating, and HCl washing of columns, were carried out. It was concluded that MW treatment may be chosen for optimal regeneration of the granulated micelle–clay complex as an efficient and low-cost procedure
Land use/land cover changes due to gold mining in the Singida region, central Tanzania: environmental and socio-economic implications
No full textThis study explored the land use and land cover (LULC) changes (1995–2023) in the gold mining hotspots of Mang’onyi, Sambaru, and Londoni in the Singida region of Tanzania. The study integrated remote sensing (RS) to evaluate the LULC transitions with social survey assessments (83 respondents) 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 km 2 (587.55%), bareland 7.70 km 2 (121.45%), and built-up areas 0.55 km 2 (134.15%), while forest and shrubs and grasses areas declined by 97.67 km 2 (− 72.59%) and 79.09 km 2 (− 43.49%), respectively. A social survey assessment revealed residents perceived environmental (deforestation, 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 resulting from mining activities. Our findings underscore the importance of balancing the economic benefits of gold mining with the imperative to protect the environment and support sustainable livelihoods in the mining regions
