In recent years, increasing wildfire activity in the western United States has led to significant emissions of smoke aerosols, impacting the atmospheric energy balance through their absorption and scattering properties. Single scattering albedo (SSA) is a key parameter that governs these radiative effects, but accurately retrieving SSA from satellites remains challenging due to limitations in sensor resolution, low sensitivity of traditional remote sensing methods, and uncertainties in radiative transfer modeling, particularly from surface reflectance and aerosol characterization. Smoke optical properties evolve rapidly after emission, influenced by fuel type, combustion conditions, and chemical aging. Accurate SSA retrieval near the source thus requires high-temporal-resolution satellite observations. Critical Reflectance (CR) method provides this capability by identifying a unique reflectance value at which top-of-atmosphere (TOA) reflectance becomes insensitive to aerosol loading and primarily reflects aerosol absorption. SSA can be retrieved from this critical reflectance. This study presents a geostationary-based CR method using the Advanced Baseline Imager (ABI) on GOES-R satellites. The approach leverages ABI's high temporal (5-10 min) and spatial (3 km) resolution, consistent viewing geometry, and wide coverage. A tailored look-up table, based on an AOD-dependent smoke model for North America, links CR to SSA. Case studies show strong agreement with AERONET measurements, with retrieval differences mostly within 0.01-well below AERONET's +/- 0.03 uncertainty. The method captures temporal and spatial variations in smoke absorption and demonstrates robustness across daylight hours. This GEO-based CR approach offers an effective tool for high-resolution SSA retrieval, contributing to improved aerosol radiative forcing estimates and climate modeling.
The coupled thermo-hydro-mechanical response caused by fire temperature transfer to surrounding rock/soil has a significant impact on tunnel safety. This study developed a numerical simulation model to evaluate the effects of fire on tunnel structures across different geological conditions. The heat transfer behavior varied with the mechanical properties and permeability of the geotechnics, concentrating within 1.0 m outside the tunnel lining and lasted for 10 days. Significant differences in pore water pressure changes were observed, with less permeable geologies experiencing greater pressure increases. Tunnel deformation was more pronounced in weaker geotechnics, though some tunnels in stronger geologies showed partial recovery post-fire. During the fire, thermal expansion created a bending moment, while a negative bending moment occurred after the fire due to tunnel damage and geotechnical coupling. The entire process led to irreversible changes in the bending moment. The depth of tunnel burial showed varying sensitivity to fire across different geological settings. This study provides important references for fire protection design and post-fire rehabilitation of tunnels under diverse geological conditions.
This study investigates the effects of incorporating date palm wood powder (DPWP) on the thermal, physical, and mechanical properties of lightweight fired earth bricks made from clay and dune sand. DPWP was added in varying proportions (0 %, 5 %, 8 %, 10 %, 12 %, and 15 % by weight of the soil matrix) to evaluate its influence on brick performance, particularly in terms of thermal insulation. Experimental results revealed that adding DPWP significantly reduced the thermal conductivity of the bricks, achieving a maximum reduction of 56.41 %. However, the inclusion of DPWP negatively impacted the physical and mechanical properties of the samples. Among the tested bricks, those with 8 % and 10 % DPWP achieved a desirable balance, maintaining satisfactory mechanical strength within acceptable standards while achieving thermal conductivity values of 0.333 and 0.279 W/m & sdot;K, representing reductions of 37.29 % and 47.46 %, respectively. To further validate these findings, prototypes of the DPWP-enhanced fired bricks and commercial bricks were constructed and tested under real environmental conditions during both summer and winter seasons, over a continuous 12-h daily period. The DPWP-enhanced prototypes demonstrated superior thermal performance, with temperature differences reaching up to 3 degrees C compared to the commercial bricks. These findings highlight the potential of DPWP as a sustainable additive for improving the thermal insulation properties of fired earth bricks, thereby promoting eco-friendly and energy-efficient building materials for sustainable construction practices.
Wildfires are increasingly recognized as a critical driver of ecosystem degradation, with post-fire hydrological and soil impacts posing significant threats to biodiversity, water quality, and long-term land productivity. In fire-prone regions, understanding how varying fire intensities exacerbate runoff and erosion is essential for guiding post-fire recovery and sustainable land management. The loss of vegetation and changes in soil properties following fire events can significantly increase surface runoff and soil erosion. This study investigates the effects of varying fire intensities on runoff and sediment yield in the Kheyrud Educational Forest. Controlled burns were conducted at low, moderate, and high intensities, along with an unburned plot serving as the control. For each treatment, three replicate plots of 2 m2 were established. Runoff and sediments were measured over the course of 1 year under natural rainfall. In addition, key soil physical properties, including bulk density, penetration resistance, and particle size distribution (sand, silt, and clay fractions), were assessed to better understand the underlying mechanisms driving hydrological responses. The results revealed that bulk density and penetration resistance were lowest in the control and highest for the high-intensity fire treatment. A significant correlation was observed between bulk density, penetration resistance, and both runoff and sediment production. However, no significant correlation was found between runoff and soil texture (sand, silt, and clay content). Fire intensity had a pronounced effect on runoff and sediment, with the lowest levels recorded in the control and low-intensity fire treatment, and the highest in the high-intensity fire treatment. The total annual erosion rates were 0.88, 1.10, 1.57, and 2.24 tons/ha/year for the control, low-, moderate-, and high-intensity treatments, respectively. The study demonstrates that high-intensity fires induce substantial changes in soil structure and vegetation cover, exacerbating runoff and sediment loss. To mitigate post-fire soil degradation, proactive forest management strategies are essential. Preventive measures-such as reducing fuel loads (e.g., removing uprooted trees in beech stands), minimizing soil compaction and vegetation damage during logging operations, can help reduce the ecological impact of wildfires. These findings provide a scientific basis for adaptive management in fire-prone forests, addressing urgent needs to balance ecological resilience and human activities in wildfire-vulnerable landscapes.
This study explored the effects of forest fires on soil microbial activity in forest soils classified by rock origin (igneous, metamorphic, and sedimentary) and stratified by subsoil depth (topsoil, subsoil). Microbial activity, indicated by average well color development (AWCD) and Shannon diversity indices, was higher in undamaged topsoils compared to fire-damaged ones. In contrast, fire-damaged subsoils, particularly in metamorphic and sedimentary soils, exhibited increased microbial activity over time due to organic matter decomposition. A significant increase in substrate utilization was observed in undamaged soils across all rock types (*p < 0.05, **p < 0.01) in topsoil, with sedimentary rock exhibiting the highest microbial diversity based on Shannon indices. The dehydrogenase activity followed a similar pattern, with reduced activity in fire-damaged topsoil but higher activity in damaged metamorphic and sedimentary subsoils. Principal component analysis (PCA) linked microbial indicators (AWCD, Shannon index) to mineral compositions like orthoclase and hornblende, highlighting the role of soil chemistry in shaping microbial responses to fire. These insights advance the understanding of fire-induced changes in soil microbial functions across diverse geological contexts.
明确不同野火数据产品的一致性与不确定性是开展产品分析应用的前提与基础。FireCCI51和MOSEV是国际上广泛使用的两套野火数据产品,泛北极多年冻土区是全球野火发生的集中区与重要碳库,分析该区野火数据产品的一致性可对未来提升野火产品的数据精度、降低泛北极碳通量估算等具有重要意义。本研究运用空间分析方法,从燃烧面积与燃烧区空间位置等方面,识别了FireCCI51和MOSEV两种数据产品在泛北极多年冻土区的一致性,进而分析了两者一致区与不一致区的地理环境特征。结果表明:(1)2001~2019年FireCCI51产品的燃烧面积均大于MOSEV,且两者燃烧面积的百分比差异在7%~60%无规律波动;(2)两种产品识别的燃烧区的空间分布一致性介于27.68%~47.14%,一致区主要分布在燃烧区集中分布的地区,例如加拿大中部地区、俄罗斯中、东西伯利亚地区及其南部延伸的大兴安岭地区,不一致区除了分布在这些地区之外,还在俄罗斯南部和西西伯利亚地区分布较多;(3)高程、气候类型和植被类型均对两套数据产品的一致区分布造成一定影响。在较低海拔和常湿冷温气候地区两种产品的一致区面积占比较多,在相对较高海拔...
明确不同野火数据产品的一致性与不确定性是开展产品分析应用的前提与基础。FireCCI51和MOSEV是国际上广泛使用的两套野火数据产品,泛北极多年冻土区是全球野火发生的集中区与重要碳库,分析该区野火数据产品的一致性可对未来提升野火产品的数据精度、降低泛北极碳通量估算等具有重要意义。本研究运用空间分析方法,从燃烧面积与燃烧区空间位置等方面,识别了FireCCI51和MOSEV两种数据产品在泛北极多年冻土区的一致性,进而分析了两者一致区与不一致区的地理环境特征。结果表明:(1)2001~2019年FireCCI51产品的燃烧面积均大于MOSEV,且两者燃烧面积的百分比差异在7%~60%无规律波动;(2)两种产品识别的燃烧区的空间分布一致性介于27.68%~47.14%,一致区主要分布在燃烧区集中分布的地区,例如加拿大中部地区、俄罗斯中、东西伯利亚地区及其南部延伸的大兴安岭地区,不一致区除了分布在这些地区之外,还在俄罗斯南部和西西伯利亚地区分布较多;(3)高程、气候类型和植被类型均对两套数据产品的一致区分布造成一定影响。在较低海拔和常湿冷温气候地区两种产品的一致区面积占比较多,在相对较高海拔...
明确不同野火数据产品的一致性与不确定性是开展产品分析应用的前提与基础。FireCCI51和MOSEV是国际上广泛使用的两套野火数据产品,泛北极多年冻土区是全球野火发生的集中区与重要碳库,分析该区野火数据产品的一致性可对未来提升野火产品的数据精度、降低泛北极碳通量估算等具有重要意义。本研究运用空间分析方法,从燃烧面积与燃烧区空间位置等方面,识别了FireCCI51和MOSEV两种数据产品在泛北极多年冻土区的一致性,进而分析了两者一致区与不一致区的地理环境特征。结果表明:(1)2001~2019年FireCCI51产品的燃烧面积均大于MOSEV,且两者燃烧面积的百分比差异在7%~60%无规律波动;(2)两种产品识别的燃烧区的空间分布一致性介于27.68%~47.14%,一致区主要分布在燃烧区集中分布的地区,例如加拿大中部地区、俄罗斯中、东西伯利亚地区及其南部延伸的大兴安岭地区,不一致区除了分布在这些地区之外,还在俄罗斯南部和西西伯利亚地区分布较多;(3)高程、气候类型和植被类型均对两套数据产品的一致区分布造成一定影响。在较低海拔和常湿冷温气候地区两种产品的一致区面积占比较多,在相对较高海拔...
明确不同野火数据产品的一致性与不确定性是开展产品分析应用的前提与基础。FireCCI51和MOSEV是国际上广泛使用的两套野火数据产品,泛北极多年冻土区是全球野火发生的集中区与重要碳库,分析该区野火数据产品的一致性可对未来提升野火产品的数据精度、降低泛北极碳通量估算等具有重要意义。本研究运用空间分析方法,从燃烧面积与燃烧区空间位置等方面,识别了FireCCI51和MOSEV两种数据产品在泛北极多年冻土区的一致性,进而分析了两者一致区与不一致区的地理环境特征。结果表明:(1)2001~2019年FireCCI51产品的燃烧面积均大于MOSEV,且两者燃烧面积的百分比差异在7%~60%无规律波动;(2)两种产品识别的燃烧区的空间分布一致性介于27.68%~47.14%,一致区主要分布在燃烧区集中分布的地区,例如加拿大中部地区、俄罗斯中、东西伯利亚地区及其南部延伸的大兴安岭地区,不一致区除了分布在这些地区之外,还在俄罗斯南部和西西伯利亚地区分布较多;(3)高程、气候类型和植被类型均对两套数据产品的一致区分布造成一定影响。在较低海拔和常湿冷温气候地区两种产品的一致区面积占比较多,在相对较高海拔...
明确不同野火数据产品的一致性与不确定性是开展产品分析应用的前提与基础。FireCCI51和MOSEV是国际上广泛使用的两套野火数据产品,泛北极多年冻土区是全球野火发生的集中区与重要碳库,分析该区野火数据产品的一致性可对未来提升野火产品的数据精度、降低泛北极碳通量估算等具有重要意义。本研究运用空间分析方法,从燃烧面积与燃烧区空间位置等方面,识别了FireCCI51和MOSEV两种数据产品在泛北极多年冻土区的一致性,进而分析了两者一致区与不一致区的地理环境特征。结果表明:(1)2001~2019年FireCCI51产品的燃烧面积均大于MOSEV,且两者燃烧面积的百分比差异在7%~60%无规律波动;(2)两种产品识别的燃烧区的空间分布一致性介于27.68%~47.14%,一致区主要分布在燃烧区集中分布的地区,例如加拿大中部地区、俄罗斯中、东西伯利亚地区及其南部延伸的大兴安岭地区,不一致区除了分布在这些地区之外,还在俄罗斯南部和西西伯利亚地区分布较多;(3)高程、气候类型和植被类型均对两套数据产品的一致区分布造成一定影响。在较低海拔和常湿冷温气候地区两种产品的一致区面积占比较多,在相对较高海拔...