Landslides are highly dangerous phenomena that occur in different parts of the world and pose significant threats to human populations. Intense rainfall events are the main triggering process for landslides in urbaniz...Landslides are highly dangerous phenomena that occur in different parts of the world and pose significant threats to human populations. Intense rainfall events are the main triggering process for landslides in urbanized slope regions, especially those considered high-risk areas. Various other factors contribute to the process;thus, it is essential to analyze the causes of such incidents in all possible ways. Soil moisture plays a critical role in the Earth’s surface-atmosphere interaction systems;hence, measurements and their estimations are crucial for understanding all processes involved in the water balance, especially those related to landslides. Soil moisture can be estimated from in-situ measurements using different sensors and techniques, satellite remote sensing, hydrological modeling, and indicators to index moisture conditions. Antecedent soil moisture can significantly impact runoff for the same rainfall event in a watershed. The Antecedent Precipitation Index (API) or “retained rainfall,” along with the antecedent moisture condition from the Natural Resources Conservation Service, is generally applied to estimate runoff in watersheds where data is limited or unavailable. This work aims to explore API in estimating soil moisture and establish thresholds based on landslide occurrences. The estimated soil moisture will be compared and calibrated using measurements obtained through multisensor capacitance probes installed in a high-risk area located in the mountainous region of Campos do Jordão municipality, São Paulo, Brazil. The API used in the calculation has been modified, where the recession coefficient depends on air temperature variability as well as the climatological mean temperature, which can be considered as losses in the water balance due to evapotranspiration. Once the API is calibrated, it will be used to extrapolate to the entire watershed and consequently estimate soil moisture. By utilizing recorded mass movements and comparing them with API and soil moisture, it will be possible to determine thresholds, thus enabling anticipation of landslide occurrences.展开更多
Deep mining,characterized by high stress,elevated geothermal gradients,and significant moisture content,significantly increases the risk of Coal Spontaneous Combustion(CSC),posing a major threat to mine safety.This st...Deep mining,characterized by high stress,elevated geothermal gradients,and significant moisture content,significantly increases the risk of Coal Spontaneous Combustion(CSC),posing a major threat to mine safety.This study delves into the impact of these factors on the self-ignition properties of coal,leveraging data from four distinctmines inHeilongjiang Province,China:ShuangyashanDongrongNo.2 Mine,Hegang JundeCoal Mine,Qitaihe Longhu Coal Mine,and Jixi Ronghua No.1Mine.We have honed the theoretical framework to account for variations in gas content during CSC.Our investigation,conducted through programmed temperature rise experiments,scrutinized the generation and temperature-dependent evolution of gases,emphasizing individual indicators such as CO,O_(2),and CxHy,in addition to composite indicators like the ratio of change in CO to change in O_(2) concentration(∂C_(CO)/∂t:−∂C_(O_(2))/∂t)and the ratio of C2H4 to C_(2)H_(6).These insights have catalyzed the development of a CSC state energy level transition model and a precise method for phase-based quantification of combustion progression.Our findings furnish a scientific foundation for the formulation of early warning and prevention strategies in deep mining settings.展开更多
文摘Landslides are highly dangerous phenomena that occur in different parts of the world and pose significant threats to human populations. Intense rainfall events are the main triggering process for landslides in urbanized slope regions, especially those considered high-risk areas. Various other factors contribute to the process;thus, it is essential to analyze the causes of such incidents in all possible ways. Soil moisture plays a critical role in the Earth’s surface-atmosphere interaction systems;hence, measurements and their estimations are crucial for understanding all processes involved in the water balance, especially those related to landslides. Soil moisture can be estimated from in-situ measurements using different sensors and techniques, satellite remote sensing, hydrological modeling, and indicators to index moisture conditions. Antecedent soil moisture can significantly impact runoff for the same rainfall event in a watershed. The Antecedent Precipitation Index (API) or “retained rainfall,” along with the antecedent moisture condition from the Natural Resources Conservation Service, is generally applied to estimate runoff in watersheds where data is limited or unavailable. This work aims to explore API in estimating soil moisture and establish thresholds based on landslide occurrences. The estimated soil moisture will be compared and calibrated using measurements obtained through multisensor capacitance probes installed in a high-risk area located in the mountainous region of Campos do Jordão municipality, São Paulo, Brazil. The API used in the calculation has been modified, where the recession coefficient depends on air temperature variability as well as the climatological mean temperature, which can be considered as losses in the water balance due to evapotranspiration. Once the API is calibrated, it will be used to extrapolate to the entire watershed and consequently estimate soil moisture. By utilizing recorded mass movements and comparing them with API and soil moisture, it will be possible to determine thresholds, thus enabling anticipation of landslide occurrences.
基金This paper is supported by“Unveiling the List and Leading the Way”Science and Technology Research Project from Heilongjiang Province(2021ZXJ02A03)Major Science and Technology Support Action Plan for the“Millions”Project in Heilongjiang Province(2020ZX04A01)the Natural Science Foundation of Heilongjiang Province(LH2024E112).
文摘Deep mining,characterized by high stress,elevated geothermal gradients,and significant moisture content,significantly increases the risk of Coal Spontaneous Combustion(CSC),posing a major threat to mine safety.This study delves into the impact of these factors on the self-ignition properties of coal,leveraging data from four distinctmines inHeilongjiang Province,China:ShuangyashanDongrongNo.2 Mine,Hegang JundeCoal Mine,Qitaihe Longhu Coal Mine,and Jixi Ronghua No.1Mine.We have honed the theoretical framework to account for variations in gas content during CSC.Our investigation,conducted through programmed temperature rise experiments,scrutinized the generation and temperature-dependent evolution of gases,emphasizing individual indicators such as CO,O_(2),and CxHy,in addition to composite indicators like the ratio of change in CO to change in O_(2) concentration(∂C_(CO)/∂t:−∂C_(O_(2))/∂t)and the ratio of C2H4 to C_(2)H_(6).These insights have catalyzed the development of a CSC state energy level transition model and a precise method for phase-based quantification of combustion progression.Our findings furnish a scientific foundation for the formulation of early warning and prevention strategies in deep mining settings.
