Rapid estimates of impact areas following large earthquakes constitute the cornerstone of emergency response scenarios.However,collecting information through traditional practices usually requires a large amount of ma...Rapid estimates of impact areas following large earthquakes constitute the cornerstone of emergency response scenarios.However,collecting information through traditional practices usually requires a large amount of manpower and material resources,slowing the response time.Social media has emerged as a source of real-time‘citizen-sensor data’for disasters and can thus contribute to the rapid acquisition of disaster information.This paper proposes an approach to quickly estimate the impact area following a large earthquake via social media.Specifically,a spatial logistic growth model(SLGM)is proposed to describe the spatial growth of citizen-sensor data influenced by the earthquake impact strength after an earthquake;a framework is then developed to estimate the earthquake impact area by combining social media data and other auxiliary data based on the SLGM.The reliability of our approach is demonstrated in two earthquake cases by comparing the detected areas with official intensity maps,and the time sensitivity of the social media data in the SLGM is discussed.The results illustrate that our approach can effectively estimate the earthquake impact area.We verify the external validity of our model across other earthquake events and provide further insights into extracting more valuable earthquake information using social media.展开更多
The air quality model CMAQ-MADRID （Community Multiscale Air Quality-Model of Aerosol Dynamics, Reaction, Ionization and Dissolution） was employed to simulate summer O3 formation in Beijing China, in order to explore...The air quality model CMAQ-MADRID （Community Multiscale Air Quality-Model of Aerosol Dynamics, Reaction, Ionization and Dissolution） was employed to simulate summer O3 formation in Beijing China, in order to explore the impacts of four heterogeneous reactions on O3 formation in an urban area. The results showed that the impacts were obvious and exhibited the characteristics of a typical response of a VOC-limited regime in the urban area. For the four heterogeneous reactions considered, the NO2 and HO2 heterogeneous reactions have the most severe impacts on O3 formation. During the O3 formation period, the NO2 heterogeneous reaction increased new radical creation by 30%, raising the atmospheric activity as more NO→NO2 conversion occurred, thus causing the O3 to rise. The increase of O3 peak concentration reached a maximum value of 67 ppb in the urban area. In the morning hours, high NO titration reduced the effect of the photolysis of HONO, which was produced heterogeneously at night in the surface layer. The NO2 heterogeneous reaction in the daytime is likely one of the major reasons causing the O3 increase in the Beijing urban area. The HO2 heterogeneous reaction accelerated radical termination, resulting in a decrease of the radical concentration by 44% at the most. O3 peak concentration decreased by a maximum amount of 24 ppb in the urban area. The simulation results were improved when the heterogeneous reactions were included, with the O3 and HONO model results close to the observations.展开更多
These days, human activities in the savanna and the remaining dry and riparian forests of the Sudanian ecoregions continue to have their impact. These anthropogenic practices are still the main cause of disturbances i...These days, human activities in the savanna and the remaining dry and riparian forests of the Sudanian ecoregions continue to have their impact. These anthropogenic practices are still the main cause of disturbances in these areas. In order to investigate and assess the importance of these disturbances, caused by people bordering on protected areas and to determine the relation between these activities and the environment in which they are carried out, 220 samples were selected in the three main protected areas of northern Togo. The investigation was mainly qualitative, considering the floristic sampling of this drought area; any anthropogenic activities observed were recorded. A simple investigative questionnaire about the activities of rural people in the reserved areas was distributed to individuals encountered in the study area. Each sample in the investigation ended with a site description of its ecologi- cal characterization, i.e., soil features, topography, fauna footprints, dominant plant species and GPS position; we also took photo- graphs of the site. Data processing was entirely based on descriptive statistics and a factor analysis. The results show that eight kinds of human activities, i.e., the use of pastures, tree cutting, bush fires, charcoal production, harvesting of plant material, fanning, honey harvesting and hunting, were noted to be serious disturbances to the integrity of the ecosystems. Among these disturbances, three are recurrent in all the sampled areas of which the use of pastures accounts for 31.88%, tree cutting for 30.35% and bush fires for 30.13%. Fire and pasture disturbances are closely linked and are responsible for the current features of the savanna area of the region. Tree cutting is more a direct function of the need for the production of wood fuel, generally used by city populations. Hunting, farm- ing and honey production are of lesser importance in the area and therefore, do not pose a significantly negative effect on the growth of fauna and flora. Knowledge of these disturbances in the context of requalification and a renewed demarcation of protected areas in Togo is essential for their sustainable management.展开更多
In this paper the impacts of the anomalous SST in the warm pool area of the Western Equatorial Pacific on the winter time circulation and the East Asian monsoon are studied by using the NCAR CCM. It is found that the ...In this paper the impacts of the anomalous SST in the warm pool area of the Western Equatorial Pacific on the winter time circulation and the East Asian monsoon are studied by using the NCAR CCM. It is found that the abnormal heating in the warm pool area will change the strength and the position of the Walker Cell in the Equatorial Pacific and the anti-Walker Cell in the equatorial Indian Ocean. Both the Walker and anti-Walker Cells are strengthened. The local Hadley Cells over two hemispheres near the warm pool are also strengthened. The subtropical highs in two hemispheres become stronger and move poleward slightly. The westerly jets in the extratropical regions have similar changes as the subtropical highs. The winter monsoon in South-East Asia is weakened by the abnormal heating in the warm pool. The experiment also show that there are wave trains emanating from surrounding areas of the warm pool to the high latitudes, causing various changes in circulations and local weather.展开更多
In Guizhou Province,karst areas and springs are widely distributed,and hydrogeological conditions are complex in mining areas. Usually there are many hydrogeological units in a mining area,and the hydrogeological cond...In Guizhou Province,karst areas and springs are widely distributed,and hydrogeological conditions are complex in mining areas. Usually there are many hydrogeological units in a mining area,and the hydrogeological conditions are very different from that of most northern mining areas in China. In view of the uniqueness of mining areas in Guizhou Province,taking Zhijin area of Zhina mining area as an example,the planning characteristics of mining areas and characteristics of groundwater environment in Guizhou Province were analyzed firstly,and then the characteristics and key considerations of groundwater environmental impact assessment in mining areas of Guizhou Province were studied. For example,when the height of water flowing fractured zone,impact radius,and the amount of water resources affected are calculated,it is necessary to analyze and evaluate as many typical mines as possible. The impact on springs as the sources of residents＇ drinking water should be analyzed one by one.展开更多
Natural conditions in Bashang area are characterized by zonal transitions which are liable to be impacted by natural disasters and intensified human activities. The extremely fragile eco-environment is also liable to ...Natural conditions in Bashang area are characterized by zonal transitions which are liable to be impacted by natural disasters and intensified human activities. The extremely fragile eco-environment is also liable to have desertification formed and developed. In the 18 years from 1978 to 1996, the desertified land area of Bashang within the scope of the map nearly doubled, a total increase of 2199.11 km2, averaging an increase of 122.17 km2 per year. Moreover, the seriously desertified area increases rapidly. Land desertification in Bashang is the combined result of natural factors and irrational human economic activities. Cultivated land expansion, population growth, and overgrazing aggrevate desertification development.展开更多
Large scale open cut coal mining operations have significant impacts to groundwater in surrounding areas in both active and post-mining phases. The prediction of water inflows into a surface mine excavation is one of ...Large scale open cut coal mining operations have significant impacts to groundwater in surrounding areas in both active and post-mining phases. The prediction of water inflows into a surface mine excavation is one of the many components involved in mine design phase. Groundwater performance also reacts to mining activities from the operational, economic and safety implications perspective. Under NSW planning legislation, as part of the comprehensive risk assessment, a groundwater impact assessment has to be conducted for a coal project to predict and mitigate the impacts in consideration of the government requirements. In this paper, the groundwater assessment modelling of mine pits was discussed in predicting of groundwater inflows and reviewing analytical and numerical approaches. A methodology of groundwater impact assessment for an open cut mine in NSW with a three-dimensional groundwater flow model Modflow Surfact demonstrated its functions in simulating the project's impacts on the groundwater regime. The key findings with mitigations are discussed and recommended in the paper to reduce impacts on groundwater and fulfil regulation requirements in NSW.展开更多
Land reclamation is gradually posing negative impact on man due to unplanned urbanization. A study was carried out on impact of land reclamation through sand mining of coastal communities in Ikate and Ilubirin in Lago...Land reclamation is gradually posing negative impact on man due to unplanned urbanization. A study was carried out on impact of land reclamation through sand mining of coastal communities in Ikate and Ilubirin in Lagos, Nigeria. Ten waters (8 surface and 2 groundwater sources), 10 soil samples and air were collected and taken for analysis. Results of water revealed concentrations lower than WHO (2017) and SON (2007) standards. Soil/sediment with average crustal value revealed Pb and Cd above standard values, which is attributed to anthropogenic influence on soils. Quality of air in the study was mainly particulate matter arising from the sea and reclaimed land in the surroundings of the environment with the highest Total Suspended Particulate of 0.8 mg/m3 in sulfur dioxide. This explains corrosion found on the roofs of the communities. Therefore, in the development planning adequate precautions should be put in place to avert environmental degradation.展开更多
Managers at Glacier Bay National Park must annually determine the allowable number of cruise-ship entries into the park. This decision considers how differences in visitor volume may affect park resources. This study ...Managers at Glacier Bay National Park must annually determine the allowable number of cruise-ship entries into the park. This decision considers how differences in visitor volume may affect park resources. This study quantified the impacts to air quality and visibility under different ship quotas using simulations with the Weather Research and Forecasting model inline coupled with chemistry. Results of the simulation assuming two entries per day for May 15 to September 15, 2008 (QTA;248 ship entries representing a 35% increase) were compared to those of the 2008 cruise-ship activity (REF;184) during that timeframe. A simulation without anthropogenic emissions (CLN) served to assess the overall impacts of cruise-ship emissions on visibility and air quality in Glacier Bay. Compared to REF, the increased entry quotas shifted chemical regimes and aerosol composition, depending upon thermodynamical conditions, and ambient concentrations. On days with notable regime shifts, sulfur-dioxide concentrations deceased while ammonium-sulfate aerosol concentrations increased. The increased quotas also altered the fine-to-coarse aerosol ratios in both directions despite constant ratio of fine-to-coarse aerosol emissions. In Glacier Bay, the days with worst visibility coincided with high relative humidity, although this relationship varied by scenario. On the 20% worst days, mean visibility was slightly better in CLN (mean haze index over Glacier Bay waters = 2.9 dv) than in REF ( = 3.1 dv). While increased emissions in QTA reduced mean visibility by 0.1 dv, the 10th, 50th and 90th percentile of haze indices remained identical to those in REF. Best (worst) visibility occurred on the same days in REF and QTA due to emission impacts, but on different days than in CLN because relative humidity solely governed visibility in CLN. While calm wind played no role for visibility in CLN, wind speed gained similar importance for visibility as relative humidity in REF and QTA. Overall, increasing ship quotas would only marginally affect air quality and visibility as compared to REF, although even small changes in these parameters need careful consideration in the context of conserving the values of Glacier Bay.展开更多
基金supported by National Natural Science Foundation of China[grant number 41271399].
文摘Rapid estimates of impact areas following large earthquakes constitute the cornerstone of emergency response scenarios.However,collecting information through traditional practices usually requires a large amount of manpower and material resources,slowing the response time.Social media has emerged as a source of real-time‘citizen-sensor data’for disasters and can thus contribute to the rapid acquisition of disaster information.This paper proposes an approach to quickly estimate the impact area following a large earthquake via social media.Specifically,a spatial logistic growth model(SLGM)is proposed to describe the spatial growth of citizen-sensor data influenced by the earthquake impact strength after an earthquake;a framework is then developed to estimate the earthquake impact area by combining social media data and other auxiliary data based on the SLGM.The reliability of our approach is demonstrated in two earthquake cases by comparing the detected areas with official intensity maps,and the time sensitivity of the social media data in the SLGM is discussed.The results illustrate that our approach can effectively estimate the earthquake impact area.We verify the external validity of our model across other earthquake events and provide further insights into extracting more valuable earthquake information using social media.
文摘The air quality model CMAQ-MADRID （Community Multiscale Air Quality-Model of Aerosol Dynamics, Reaction, Ionization and Dissolution） was employed to simulate summer O3 formation in Beijing China, in order to explore the impacts of four heterogeneous reactions on O3 formation in an urban area. The results showed that the impacts were obvious and exhibited the characteristics of a typical response of a VOC-limited regime in the urban area. For the four heterogeneous reactions considered, the NO2 and HO2 heterogeneous reactions have the most severe impacts on O3 formation. During the O3 formation period, the NO2 heterogeneous reaction increased new radical creation by 30%, raising the atmospheric activity as more NO→NO2 conversion occurred, thus causing the O3 to rise. The increase of O3 peak concentration reached a maximum value of 67 ppb in the urban area. In the morning hours, high NO titration reduced the effect of the photolysis of HONO, which was produced heterogeneously at night in the surface layer. The NO2 heterogeneous reaction in the daytime is likely one of the major reasons causing the O3 increase in the Beijing urban area. The HO2 heterogeneous reaction accelerated radical termination, resulting in a decrease of the radical concentration by 44% at the most. O3 peak concentration decreased by a maximum amount of 24 ppb in the urban area. The simulation results were improved when the heterogeneous reactions were included, with the O3 and HONO model results close to the observations.
基金supported by the Chinese and Togolese governments under the direction of Beijing Forestry University and Universitéde Lomé
文摘These days, human activities in the savanna and the remaining dry and riparian forests of the Sudanian ecoregions continue to have their impact. These anthropogenic practices are still the main cause of disturbances in these areas. In order to investigate and assess the importance of these disturbances, caused by people bordering on protected areas and to determine the relation between these activities and the environment in which they are carried out, 220 samples were selected in the three main protected areas of northern Togo. The investigation was mainly qualitative, considering the floristic sampling of this drought area; any anthropogenic activities observed were recorded. A simple investigative questionnaire about the activities of rural people in the reserved areas was distributed to individuals encountered in the study area. Each sample in the investigation ended with a site description of its ecologi- cal characterization, i.e., soil features, topography, fauna footprints, dominant plant species and GPS position; we also took photo- graphs of the site. Data processing was entirely based on descriptive statistics and a factor analysis. The results show that eight kinds of human activities, i.e., the use of pastures, tree cutting, bush fires, charcoal production, harvesting of plant material, fanning, honey harvesting and hunting, were noted to be serious disturbances to the integrity of the ecosystems. Among these disturbances, three are recurrent in all the sampled areas of which the use of pastures accounts for 31.88%, tree cutting for 30.35% and bush fires for 30.13%. Fire and pasture disturbances are closely linked and are responsible for the current features of the savanna area of the region. Tree cutting is more a direct function of the need for the production of wood fuel, generally used by city populations. Hunting, farm- ing and honey production are of lesser importance in the area and therefore, do not pose a significantly negative effect on the growth of fauna and flora. Knowledge of these disturbances in the context of requalification and a renewed demarcation of protected areas in Togo is essential for their sustainable management.
文摘In this paper the impacts of the anomalous SST in the warm pool area of the Western Equatorial Pacific on the winter time circulation and the East Asian monsoon are studied by using the NCAR CCM. It is found that the abnormal heating in the warm pool area will change the strength and the position of the Walker Cell in the Equatorial Pacific and the anti-Walker Cell in the equatorial Indian Ocean. Both the Walker and anti-Walker Cells are strengthened. The local Hadley Cells over two hemispheres near the warm pool are also strengthened. The subtropical highs in two hemispheres become stronger and move poleward slightly. The westerly jets in the extratropical regions have similar changes as the subtropical highs. The winter monsoon in South-East Asia is weakened by the abnormal heating in the warm pool. The experiment also show that there are wave trains emanating from surrounding areas of the warm pool to the high latitudes, causing various changes in circulations and local weather.
文摘In Guizhou Province,karst areas and springs are widely distributed,and hydrogeological conditions are complex in mining areas. Usually there are many hydrogeological units in a mining area,and the hydrogeological conditions are very different from that of most northern mining areas in China. In view of the uniqueness of mining areas in Guizhou Province,taking Zhijin area of Zhina mining area as an example,the planning characteristics of mining areas and characteristics of groundwater environment in Guizhou Province were analyzed firstly,and then the characteristics and key considerations of groundwater environmental impact assessment in mining areas of Guizhou Province were studied. For example,when the height of water flowing fractured zone,impact radius,and the amount of water resources affected are calculated,it is necessary to analyze and evaluate as many typical mines as possible. The impact on springs as the sources of residents＇ drinking water should be analyzed one by one.
基金National Natural Science Foundation of China No. 49894170
文摘Natural conditions in Bashang area are characterized by zonal transitions which are liable to be impacted by natural disasters and intensified human activities. The extremely fragile eco-environment is also liable to have desertification formed and developed. In the 18 years from 1978 to 1996, the desertified land area of Bashang within the scope of the map nearly doubled, a total increase of 2199.11 km2, averaging an increase of 122.17 km2 per year. Moreover, the seriously desertified area increases rapidly. Land desertification in Bashang is the combined result of natural factors and irrational human economic activities. Cultivated land expansion, population growth, and overgrazing aggrevate desertification development.
文摘Large scale open cut coal mining operations have significant impacts to groundwater in surrounding areas in both active and post-mining phases. The prediction of water inflows into a surface mine excavation is one of the many components involved in mine design phase. Groundwater performance also reacts to mining activities from the operational, economic and safety implications perspective. Under NSW planning legislation, as part of the comprehensive risk assessment, a groundwater impact assessment has to be conducted for a coal project to predict and mitigate the impacts in consideration of the government requirements. In this paper, the groundwater assessment modelling of mine pits was discussed in predicting of groundwater inflows and reviewing analytical and numerical approaches. A methodology of groundwater impact assessment for an open cut mine in NSW with a three-dimensional groundwater flow model Modflow Surfact demonstrated its functions in simulating the project's impacts on the groundwater regime. The key findings with mitigations are discussed and recommended in the paper to reduce impacts on groundwater and fulfil regulation requirements in NSW.
文摘Land reclamation is gradually posing negative impact on man due to unplanned urbanization. A study was carried out on impact of land reclamation through sand mining of coastal communities in Ikate and Ilubirin in Lagos, Nigeria. Ten waters (8 surface and 2 groundwater sources), 10 soil samples and air were collected and taken for analysis. Results of water revealed concentrations lower than WHO (2017) and SON (2007) standards. Soil/sediment with average crustal value revealed Pb and Cd above standard values, which is attributed to anthropogenic influence on soils. Quality of air in the study was mainly particulate matter arising from the sea and reclaimed land in the surroundings of the environment with the highest Total Suspended Particulate of 0.8 mg/m3 in sulfur dioxide. This explains corrosion found on the roofs of the communities. Therefore, in the development planning adequate precautions should be put in place to avert environmental degradation.
基金the National Park Service(Cooperative Ecosystem Studies Unit,contract P11AT30883/P11AC90465)for financial support.
文摘Managers at Glacier Bay National Park must annually determine the allowable number of cruise-ship entries into the park. This decision considers how differences in visitor volume may affect park resources. This study quantified the impacts to air quality and visibility under different ship quotas using simulations with the Weather Research and Forecasting model inline coupled with chemistry. Results of the simulation assuming two entries per day for May 15 to September 15, 2008 (QTA;248 ship entries representing a 35% increase) were compared to those of the 2008 cruise-ship activity (REF;184) during that timeframe. A simulation without anthropogenic emissions (CLN) served to assess the overall impacts of cruise-ship emissions on visibility and air quality in Glacier Bay. Compared to REF, the increased entry quotas shifted chemical regimes and aerosol composition, depending upon thermodynamical conditions, and ambient concentrations. On days with notable regime shifts, sulfur-dioxide concentrations deceased while ammonium-sulfate aerosol concentrations increased. The increased quotas also altered the fine-to-coarse aerosol ratios in both directions despite constant ratio of fine-to-coarse aerosol emissions. In Glacier Bay, the days with worst visibility coincided with high relative humidity, although this relationship varied by scenario. On the 20% worst days, mean visibility was slightly better in CLN (mean haze index over Glacier Bay waters = 2.9 dv) than in REF ( = 3.1 dv). While increased emissions in QTA reduced mean visibility by 0.1 dv, the 10th, 50th and 90th percentile of haze indices remained identical to those in REF. Best (worst) visibility occurred on the same days in REF and QTA due to emission impacts, but on different days than in CLN because relative humidity solely governed visibility in CLN. While calm wind played no role for visibility in CLN, wind speed gained similar importance for visibility as relative humidity in REF and QTA. Overall, increasing ship quotas would only marginally affect air quality and visibility as compared to REF, although even small changes in these parameters need careful consideration in the context of conserving the values of Glacier Bay.
