Forests constitute a key component of the Earth system but the sustainability of the forest reserves in the semi-arid zone is a real concern since its vegetation is very sensitive to the climate fluctuation. The understanding of the mechanisms for the vegetation–climate interaction is poorly studied in the context of African Sahel. In this study, the characteristics of the vegetation response to the fluctuations of precipitation and temperature is determined for the forest reserve of Fina. Rainfall estimates, air temperature and NDVI were re-gridded to a same spatial resolution and standardized with respect to their respective long-term mean. Lag-correlations analysis was used to estimate lag times between changes of climate variables and vegetation response at both seasonal and interannual bases. Results show increasing tendency of NDVI started from the 1990s coinciding the recovery of the rainfall from the 1980s drought, and the obtained correlation (r = 0.66) is statistically significant (p value < 0.01). The strongest responses of vegetation to rainfall and temperature fluctuations were found after 30 and 15 days, respectively. Moreover, at a shorter time lag (e.g., 15 days), more pronounced vegetation responses to both rainfall and temperature were found in agriculturally dominated land while at a longer time lag (e.g., 30 days), a stronger response was observed in Bare-dominated land. The vegetation response to the climate fluctuation is modulated by the land-use/cover dynamics.

Mali is endowed with significant untapped renewable energy potentials paradoxically the country is identified as an energy-poor nation characterized by very high dependency on imports of petroleum products and heavy reliance on biomass (wood-fuel and charcoal). Access to electricity remains very low, with significant disparities across urban and rural remote areas. The gap between the electricity demand and supply keeps increasing yearly, and power shortages get frequent and longer, especially during dry periods from March to June. The energy demand increase, due to of population grow and rapid urbanization (causing more use of fossil fuels resources in the energy mix) bears the unsustainability of the country’s current energy supply. The challenge for the country is then to meet this growing energy demand with a sustainable energy supply system. In the present work, Analytical Hierarchy Process technique is applied to perform Multicriteria Decision Making analysis to identify and assess the most sustainable long-term energy supply options in Mali considering technical, environmental, social, and economic dimensions. The current situation and five alternatives of energy supply based on the country’s current and future energy supply and climate change policies are proposed for assessment. Results show that the highest priority indicators by stakeholders’ survey are under economical dimension followed by the technical ones. The best scenario considers deploying renewable energy to up to 42% of the energy mix as the sustainable option for energy supply. Adopting such scenario requires measures as a strong political will to subsidize renewable energy equipment in order to make them affordable and also policies that encourage the use of renewable energy (such as lower taxes and duties). The suggested framework gives decision-makers, authorities, practitioners, and researches an effective tool for the country future energy planning.

Monitoring surface water quality on a spatio-temporal scale is very important to restrict the entry of polluting components into water bodies, particularly rivers. Traditional techniques of assessing water quality are typically costly and time-consuming. With the advent of remote sensing technologies and the availability of high-resolution satellite images in recent years, a significant opportunity for water quality monitoring has arisen. Our study aims to test the use of Sentienl-2 multispectral imaging sensors in estimating three important water quality parameters: chlorophyll-a, Colored Dissolved Organic Matter and Total Suspended Matter in Niger River. Sentinel-2 satellite data were acquired in 2020. Atmospheric correction was performed using Sen2cor from the Sentinel toolbox to obtain a geometrically corrected Sentinel-2 multispectral image. We selected multiple water-body indices from the literature based on their spectral reflection characteristics, analyze correlations between the reflectance values of water body indices and the water quality parameters of synchronous measured sampling points in order to obtain an optimal water body index for estimating water quality parameters (WQP) in Niger River. Five regression functions were used in this study: linear regression, exponential, logarithmic, power and polynomial regression. The performance and accuracy of these regression models were evaluated by correlating spectral reflectance band ratio against the in situ water quality parameters (WQP) concentrations. Polynomial regression gave a higher performance and accuracy based on their R values. The best spectral index was selected to assess the spatio-temporal distribution of water pollutants in the Niger River in Bamako and its surroundings. The results showed that the polynomial regression of 6th degree provided the best fit had the best spectral band ratio and in situ Chl-a, CDOM and TSM concentrations which were respectively achieved with band index of B2/B3 (R² = 0.78), B3/B6 (R ² = 0.79) and B3/B4 (R ² = 0.63). Therefore, the best band ratio was selected to evaluate Chl-a spatio-temporal in Niger River water in Bamako. The results of this study showed seasonal variability of the water pollutants in the Niger River. This highlights the potential of the Sentinel-2 products for water quality analysis. As a conclusion, the Sentinel-2 images could be helpful for precise water quality control of Niger River in Bamako.

Stratospheric Aerosol Injection (SAI) emerges as a geoengineering strategy to mitigate global warming by reflecting sunlight back into space. However, this approach raises significant concerns, particularly regarding its impact on rainfall characteristics in the Sahel. This study investigates the effects of injecting sulfur dioxide (SO2) into the stratosphere using the IPSL-CM5A-LR climate model, under two forcing scenarios: RCP4.5 (Representative Concentration Pathway of 4.5 W m–²) and a combination of RCP4.5 with geoengineering forcing (G3). The analysis focuses on future climate conditions in the Sahel, based on 30-year averages over two distinct periods: 2020–2050 and 2050–2080. The results highlight notable differences between the “with injection” and “without injection” scenarios. The number of consecutive wet days (CWD) increases with SO2 injection, indicating prolonged rainfall periods. Annual total precipitation on wet days (PRCPTOT) exhibits a slight upward trend with SO2 injection, potentially mitigating drought effects. Conversely, maximum daily precipitation (Rx1day) and five-day precipitation (Rx5day) are slightly higher in the absence of injection, suggesting a reduction in extreme precipitation intensity when SO2 is introduced. The Simple Daily Intensity Index (SDII) shows moderate variations between scenarios, with a slight decrease observed under SO2 injection. These findings indicate that SO2 injection could help stabilize precipitation regimes and reduce climate extremes in the Sahel. However, further research is crucial to gaining a deeper understanding of the long-term implications of this method and optimizing its application.

Small-scale irrigation in urban and peri-urban areas plays a key role in food security and livelihood improvement in Bamako, Mali. This study evaluates the performance and constraints of 10 irrigated market gardening sites using field surveys, soil and water analyses, and crop water requirement assessments. The objective was to assess the current status of irrigation practices, identify the main agronomic and environmental constraints, and propose feasible strategies for sustainable intensification in these production systems. Results show that soils are predominantly sandy (78–98%) with low organic matter (0–2%), making them poorly fertile and highly water demanding. These soil conditions reduce water retention capacity and increase the need for frequent irrigation, which may further aggravate inefficient water use. Irrigation water quality remains generally acceptable, with no significant heavy metal contamination (<0.01 mg/L), indicating that water sources are suitable for vegetable production under the studied conditions. However, irrigation practices were found to be inefficient, with applied water exceeding crop requirements by 2 to 8 times. Irrigation efficiency is estimated at 40–50%, reflecting substantial water losses and poor control of water application at field level. Correlation analysis indicates that crop yield is more related to water application than to irrigation efficiency, suggesting that farmers tend to compensate for low efficiency by over-applying water. While this practice may help maintain production in the short term, it is neither economically nor environmentally sustainable. Excessive irrigation may also contribute to nutrient leaching and long-term soil degradation.

Soil organic carbon (SOC) stock is strongly affected by land use and land cover (LULC). changes This study assesses the vertical distribution of topsoil organic carbon stocks under five major land use types, forest, savannah woodland, shrub savannah, cropland, and mango plantations. The soil samples were collected at 0-10 cm, 10-20 cm and 20-30cm depth. The results showed significant differences (P 0.01) in SOC stocks under different LULC types. The SOC stocks decrease with depth in all LULC types. Cropland exhibited the highest SOC stock (28.21 t,ha), while shrub savannah recorded the lowest (23.70 t"ha) within the 0—30 cm horizon. Forestland in Baoulé and shrub savannah in Faya recorded the highest SOC stocks, underlining the carbon sequestration potential Of low-disturbance systems. A consistent decline in SOC with depth across all land uses emphasizes the importance Of full-profile assessments. ANOVA and MANOVA results underscore the value of full-profile SOC assessments, showing that ecosystem protection and improved orchard management are key to enhancing carbon storage and advancing climate-smart land use. The study shows that land use and soil depth jointly regulate SOC, bulk density, and PH, with clear vertical stratification even within the 0—30 cm profile. Unlike previous studies, it provides the first multi-land-use SOC assessment across two major forest reserves, revealing distinct ecological drivers Of carbon retention. These findings highlight the need for land-use- specific carbon strategies, improved orchard management, and the protection of low-disturbance ecosystems to enhance soil carbon storage and climate-smart landscape management.