This study examines the key drivers behind the continued reliance on traditional biomass fuels such as charcoal and firewood in urban areas of developing countries, including the city of Lubumbashi. The paper focuses on economic constraints, health problems associated with the use of these fuels, the environmental consequences of growing use and also looks at the alternatives for cooking and their accessibility. The various reasons behind the growing and constant use of charcoal and firewood are examined in the context of the city of Lubumbashi and other developing countries. However, the continuous supply of charcoal and firewood not only contributes to the degradation of forests and the extinction of species, but also disrupts the livelihoods of forest-dependent families and exacerbates soil erosion. The charcoal production process is intrinsically damaging to both the environment and human well-being. Not only does it emit large quantities of CO2, contributing to atmospheric pollution, but it also presents health risks for both producers and users. The smoke and soot generated during charcoal production expose people to harmful substances, leading to adverse health effects and even premature death, particularly among children. This review also discusses the impact of this production and use on the education of women and children, who are responsible for cooking and harvesting firewood, resulting in a higher illiteracy rate among women. Faced with the need to take global action to mitigate the impact of climate change, global carbon dioxide emissions must be drastically reduced to meet the Paris Agreement target of zero net emissions by 2050. A practical and sustainable solution is discussed in this review as an alternative to traditional cooking systems namely solar cooking, which offers enormous potential, provided it is accessible, and is an excellent alternative to the heavy reliance on biomass for household energy needs in developing countries.

The American Petroleum Institute (API) filter press test has been used for decades in the construction industry as part of the quality control regime for bentonite-based excavation support fluids. The industry has carried over the use of this test to polymer fluids despite the lack of published evidence of its suitability for these fluids and the very different mechanisms by which polymer fluids and bentonite slurries achieve excavation support. This paper presents the first systematic investigation of this issue through a combination of laboratory testing and theoretical analysis. The investigation demonstrates the very different behaviours of bentonite slurries and polymer fluids. In contrast to the results for bentonite slurries, API filter press results for polymers are shown to be highly sensitive to the filter paper used. In particular, repeatability testing revealed a substantial variation in the polymer fluid loss rates attributable to three primary factors: (a) the filter paper pore size, (b) filter paper damage resulting from the applied test pressure, (c) apparent 'clogging' of the filter paper pore space. Furthermore, the study demonstrates the poor repeatability of the API filter press test for polymer fluids even when filter papers of the same type are used. Interestingly, analysis of polymer flow with respect to filter paper pore size and the applied pressure showed that the filter papers were behaving as porous media rather than a simple bundle of capillaries; their behaviour could not be modelled using a simple capillary bundle model. Importantly, this finding shows that the filter press may provide a rapid method of assessing the apparent viscosity of polymer fluids in porous media at high shear rates; data which cannot be obtained by rotational viscometry, and which would otherwise require resort to permeameter testing of coarse soils. The investigation demonstrates that the filter press test is not useful for the on-site quality control of polymer fluids but, given the theory presented in the paper, it can be a useful laboratory tool that provides valuable insight into polymer fluid flow behaviour in soils of high hydraulic conductivity, the most challenging soils for polymer fluid support.

Forest management and tree felling in the stand change the structural characteristics, which causes changes in the microclimate conditions. The microclimate is a key in sustainable forest management because soil temperature and moisture regimes regulate nutrient cycling in forest ecosystems. The aim of this research was to determine the changes in air and soil temperatures in pedunculate oak forest stands in different stages of shelterwood that stimulate natural regeneration. The research was conducted in pedunculated oak forests in Spa & ccaron;va area. The microclimatic parameters were measured in a mature old forest stand without shelterwood cutting and in stands with preparatory cut, seed cut, and final cut. The intensity of shelterwood had an impact on the amplitudes and values of air and soil temperatures. The highest average air temperature was in the stand with a preparatory cut. Extreme values of air and soil temperatures were measured in the stands with a final cut. The highest air and soil temperature amplitudes were in the stand with a final cut, with the exception of most of the winter, when the highest soil temperature amplitude was in the stand with a seed cut. The highest number of icy, cold, and hot days was in the stand with a final cut. SARIMA models establish that the difference between microclimatic parameters is not accidental.

The unified effective stress equation based on suction stress, a widely accepted method for calculating effective stress in unsaturated soils, provides a closed-form solution that enables the characterization of soils in both saturated and unsaturated states. The effect of desaturation on the water content of natural and treated soils was studied with respect to unconfined compressive strength (UCS) and indirect tensile strength (ITS). The soil's moisture-dependent behavior was characterized by the van Genuchten (Soil Sci Soc Am J 44:892-898, 1980. https://doi.org/10.2136/sssaj1980.03615995004400050002x) and Lu et al. (Water Resour Res, 2010. https://doi.org/10.1029/2009wr008646) models and implemented using the equation. Suction tests were conducted using the dew point and filter paper methods, alongside UCS and ITS tests, on silty clay soil and microsilica-treated soil with microsilica contents of 5%, 10%, and 15%. The equation was validated by comparing mean total stress (p) and mean effective stress (p ') to deviatoric stress (q) and analyzing the friction angle at different suction levels. It proved applicable to both natural and treated soils, with valid moisture content ranges of 4-17.5% and 6-20%, respectively. This study experimentally confirms the equation's effectiveness in characterizing the hydro-mechanical behavior of soils under varying moisture conditions.

The rapid acceleration of urbanization, combined with the proliferation of impervious surfaces and the inherently low permeability of soil layers, has worsened urban waterlogging. This study explores the layout of filter element seepage wells within a sponge city framework to enhance rainwater infiltration and reduce surface water accumulation, proposing an optimized method for determining well spacing and depth. The optimization uses a multi-objective genetic algorithm to target the construction cost, seepage velocity, total head, and pore water pressure. A combined weighting method assigns weights to each aim, while the Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) determines the perfect spacing and depth. The results show that the optimal spacing and depth of the filter element seepage wells are 1.572 m and 2.794 m, respectively. Compared to the initial plan, the optimized scheme reduces construction costs by 21.31%, increases the rainwater infiltration efficiency by approximately 200%, raises the total hydraulic head by 17.23%, and decreases the pore water pressure by 5.73%. Sensitivity analysis shows that the optimized scheme remains stable across different weight combinations. This optimized layout significantly improves both the infiltration capacity and cost-effectiveness.

Forest logging activities negatively affect various soil properties. In this study, we focus on the logging effects on soil water retention and associated pore size distribution. We measured the soil-water characteristic curves (SWCCs) on 21 undisturbed samples from three research plots: a reference area, a clear-cut area and a forest track. A total of 12 SWCC points between saturation and wilting point were determined for each sample with a sand box and pressure plate apparatus. The trimodal behaviour is highlighted by the dependence between soil moisture and suction. Therefore, we proposed a revised model by combining two exponential expressions with the van Genuchten model. The exponential terms describe the influence of macro-and-structural porosities, and the latter is used to calculate textural porosity. This new model with eight independent parameters was suitable to fit trimodal SWCCs in all samples. Results revealed that logging had the most destructive effect on large pores, and the soil on the forest track was the most affected. Both soil-air and available water capacity were reduced and the permanent wilting point increased as a result of damage to the soil structure and pore system. Observed increased organic carbon content in compacted soils can be attributed to slowed decomposition due to reduced air capacity and increased waterlogging susceptibility of damaged soils.

Tire wear particles (TWPs) attract attention because of their harmful impact on the soil ecosystem. Nevertheless, there is limited understanding regarding how aging affects the toxicity of TWPs to soil microorganisms. Herein, a microcosm experiment was performed to compare the toxicity of pristine and UV-aged TWPs on the soil microbial community. After 28 days operation, more holes and cracks appeared on the surface of the UV-aged TWPs compared with the pristine TWPs. The diversity and community structure of soil microorganisms changed under the pristine and UV-aged TWPs exposure, with the UV-aged TWPs significantly altered nirK-type soil denitrifying bacteria. Streptomyces played an important role in connecting the nirK-type bacterial community and promoting the denitrification process under the UV-aged TWPs exposure. The soil microorganisms further promoted the membrane transport of metabolites to resist the toxic effects of UV-aged TWPs by up-regulating the ATP-binding cassette (ABC) transporters, which consumed lots of energy and led to interference in energy metabolism. Furthermore, UV-aged TWPs further stimulated the accumulation of reactive oxygen species (ROS), stimulated the soil microorganisms to secrete more extracellular polymers substances (EPS) and activated the antioxidant defense system against oxidative damage caused by UV-aged TWPs, however, the activation of SOS response in turn increased the risk of antibiotic resistance genes (ARGs) transmission.

Due to the impact of climate change and human activities, part of the Yongding River has stopped flowing, and the hydrological environment is damaged. The hydrological condition can be used to assess the ecological environment of the watershed, and analyzing the driving factors affecting the hydrological condition is essential for the environmental restoration of the watershed, but it is particularly challenging on a daily scale. This paper used the Indicators of Hydrologic Alteration and the Range of Variability Approach (IHA-RVA) method to screen out the sensitive indicators in different periods that are representative of each river; determined the hydrological variation periods of the upper Yongding River and the two subbasins, the Yang River and the Sanggan River; and quantitatively identified the contribution of climate change and different human activities (water withdrawals and reservoir storage) to the basin's runoff by constructing a daily-scale model named the Water and Energy Transfer between Soil, Plants, and Atmosphere (WetSpa) model. The results showed that the upper Yongding River, the Yang River, and the Sanggan River had a high degree of variation (87.2%), a low degree of variation (20%), and a moderate degree of variation (37.5%) in 1975-1988, 1980-1986, and 1978-1993, respectively. Human activities were the main driving factors, but their contributions varied across different basins. The Yang River is mostly affected by water withdrawals, with a contribution rate of 125.90%. The Sanggan River was affected mostly by reservoir storage, with a contribution rate of 153.47%. The upper Yongding River was affected mostly by climate change. A stricter management system can reduce the impact of human activities on runoff changes and provide a guarantee for the restoration of the ecological environment of the upper Yongding River.

The global cryosphere is retreating under ongoing climate change. The Third Pole (TP) of the Earth, which serves as a critical water source for two billion people, is also experiencing this decline. However, the interplay between rising temperatures and increasing precipitation in the TP results in complex cryospheric responses, introducing uncertainties in the future budget of TP cryospheric water (including glacier and snow water equivalents and frozen soil moisture). Using a calibrated model that integrated multiple cryospheric-hydrological components and processes, we projected the TP cryospheric water budgets under both low and high climatic forcing scenarios for the period 2021-2100 and assessed the relative impact of temperature and precipitation. Results showed (1) that despite both scenarios involving simultaneous warming and wetting, under low climatic forcing, the total cryospheric budget exhibited positive dynamics (0.017 mm yr-1 with an average of 1.77 mm), primarily driven by increased precipitation. Glacier mass loss gradually declined with the rate of retreat slowing, accompanied by negligible declines in the budget of snow water equivalent and frozen soil moisture. (2) By contrast, high climatic forcing led to negative dynamics in the total cryospheric budget (-0.056 mm yr-1 with an average of -1.08 mm) dominated by warming, with accelerated decreases in the budget of all cryospheric components. These variations were most pronounced in higher-altitude regions, indicating elevation-dependent cryospheric budget dynamics. Overall, our findings present alternative futures for the TP cryosphere, and highlight novel evidence that optimistic cryospheric outcomes may be possible under specific climate scenarios.

An understanding of the mechanical properties and macroscopic behavior of unsaturated soil can be improved through an in-depth microscopic insight of the variables controlling the soil-water characteristic curve (SWCC). In this study, the effects of the initial conditions on the pore structure and SWCC of silty soil was examined. Their relationships to the soil behavior during water loss was addressed from both macroscopic and microscopic perspectives. In this study, patterns different from those of previous studies were revealed; this especially pertained to the effect of the initial water content on the SWCC. The SWCC was obtained using repeated centrifugation and filter paper tests. Mercury intrusion porosimetry (MIP) and scanning electron microscopy (SEM) were performed to collect the microstructure information. The results showed that soils compacted using the optimal dry side conditions had double S-shaped SWCC for their bimodal pore size distributions, and these pores were classified as intra-aggregate and inter-aggregate pores. Thus, these soils underwent two distinct stages of water loss during drying, and water loss occurred more easily in the first stage because of the presence of many large macropores or inter-aggregate pores. However, soils compacted at the optimum water content produced a single S-shaped SWCC for the multimodal pore structure. Water drained from these soils at a relatively constant rate from a more homogeneous and uniform pore system. This study has provided a comprehensive set of macroscopic and microscopic experimental data and well-established relationships among the PSD, SWCC and initial state of the silty soil.