The National Disaster Reduction Center of China(NDRCC)(The Satellite Application Center for Disaster Reduction)of the Ministry of Civil Affairs(MCA)of the Peopled Repub-lic of China was established in 2002,and is a sp...The National Disaster Reduction Center of China(NDRCC)(The Satellite Application Center for Disaster Reduction)of the Ministry of Civil Affairs(MCA)of the Peopled Repub-lic of China was established in 2002,and is a specialized agency under the Chinese Government.It is engaged in infor-mation service and decision-making assistance in support of comprehensive natural disaster management.展开更多
China is one of countries with frequent natural disasters and serious disaster losses.In recent years,with the background of global climate change,the disaster risk in China grows continuously.As a high-tech means wit...China is one of countries with frequent natural disasters and serious disaster losses.In recent years,with the background of global climate change,the disaster risk in China grows continuously.As a high-tech means with large-scale,all-weather,all time and dynamic monitoring spatial and temporal changes of the Earth,satellite remote sensing technology has been widely展开更多
To better improve the emergency communication and location-based services of disaster information reporting network for serious natural response and relieL disaster emergency the national natural disaster reduction ap...To better improve the emergency communication and location-based services of disaster information reporting network for serious natural response and relieL disaster emergency the national natural disaster reduction application platform based on BeiDou navigation satellite system is constructed. The administrative distributed platform is integrated with BeiDou positioning and multiple communication ways so as to achieve main disaster reduction application services, including disaster information acquisition and monitoring, emergency relief for trapped people, on-site emergency relief command service, relief supplies＇ transportation monitoring, and disaster information publishing service. By the platform, serious disaster information reporting time may be reduced to one hour and the emergency decision-making information service for serious natural disasters can be effectively improved, and it will be helpful to provide technical references for the industrial application and promotion of BeiDou inte- grated disaster reduction.展开更多
With the global climate changes,the situation in coping with the natural disasters has become more serious and complicated.Many countries in the world focus on improving the technical support capacity for
This paper deals with the formative process of the Wenchuan earthquake disaster chain risk. Selected earthquake-landslides chain risk is critically evaluated by the probability of landslide displacement failure based ...This paper deals with the formative process of the Wenchuan earthquake disaster chain risk. Selected earthquake-landslides chain risk is critically evaluated by the probability of landslide displacement failure based on the Newmark's permanent-deformation model. In this context, a conceptual model of regional disaster chain risk assessment was proposed, in which the hazardformative environments sensitivity was the core factor as well as the main difference compared with single disaster risk assessment. The disaster chain risk is accumulation of primary disaster risk and the secondary disasters risks. Results derived from the Wenchuan case proved that the conceptual model was suitable for the disaster chain risk assessment, especially the sudden disaster chain. This experience would offer greater potential in application of conceptual model of disaster chain risk assessment, in the process of large-scale disaster risk governance.展开更多
The East Asian monsoon has a tremendous impact on agricultural production in China. An assessment of the risk of drought disaster in maize-producing regions is therefore important in ensuring a reduction in such disas...The East Asian monsoon has a tremendous impact on agricultural production in China. An assessment of the risk of drought disaster in maize-producing regions is therefore important in ensuring a reduction in such disasters and an increase in food security. A risk assessment model, EPIC（Environmental Policy Integrated Climate） model, for maize drought disasters based on the Erosion Productivity Impact Calculator crop model is proposed for areas with the topographic characteristics of the mountainous karst region in southwest China. This region has one of the highest levels of environmental degradation in China. The results showed that the hazard risk level for the maize zone of southwest China is generally high. Most hazard index values were between 0.4 and 0.5,accounting for 47.32% of total study area. However,the risk level for drought loss was low. Most of the loss rate was ＆lt;0.1, accounting for 96.24% of the total study area. The three high-risk areas were mainlydistributed in the parallel ridge–valley areas in the east of Sichuan Province, the West Mountain area of Guizhou Province, and the south of Yunnan Province.These results provide a scientific basis and support for the reduction of agricultural drought disasters and an increase in food security in the southwest China maize zone.展开更多
Environment and disaster monitoring and forecasting small satellite constellation A and B satellites(HJ-1-A,B) are called "environment and disaster reduction satellites A and B" for short.The constellation a...Environment and disaster monitoring and forecasting small satellite constellation A and B satellites(HJ-1-A,B) are called "environment and disaster reduction satellites A and B" for short.The constellation adopts a 10:30LT sun-synchronous circular orbit,with orbit altitude of 649km.HJ1-A and HJ-1-B are distributed with a phase difference of 180° in the same orbital plane,so as to enhance the time resolution of earth observation.The satellites have orbit maintenance capability,the lifetime is 3 years.Both satellites adopt CAST968 platforms.Two wide-coverage multispectral CCD cameras with resolution 30m and width 700km,a super-spectral imager with resolution 100m and width 50km as well as a data transmission subsystem of 120Mbit/s are deployed on HJ-1-A,which also carries Ka communication testing equipment of Thailand.HJ-1-B has two wide-coverage multispectral CCD cameras(the same as satellite A),one infrared camera with resolution 150m and width 720km and a data transmission subsystem of 60Mbit/s.The coverage period of the wide-coverage multispectral CCD camera is 48 hours.The revisit period of super-spectral imager is 96 hours and the coverage period ofinfrared camera is 96 hours.展开更多
0 INTRODUCTION.According to the China Earthquake Networks Center,an M6.8 earthquake struck Dingri County,Xizang Autonomous Region,China,on 7 January 2025 at 9:05 a.m.local time.The epicenter is located at 28.5°N,...0 INTRODUCTION.According to the China Earthquake Networks Center,an M6.8 earthquake struck Dingri County,Xizang Autonomous Region,China,on 7 January 2025 at 9:05 a.m.local time.The epicenter is located at 28.5°N,87.45°E,with a depth of~10 km.展开更多
Urban areas are particularly vulnerable to surface water flooding in a changing environment.A large number of urban surface water flood models have been developed to derive flood inundations and support risk managemen...Urban areas are particularly vulnerable to surface water flooding in a changing environment.A large number of urban surface water flood models have been developed to derive flood inundations and support risk management.However,unlike fluvial and coastal flooding,urban pluvial flooding is often associated with shallow water and thus the model is difficult to validate with traditional monitoring data.In this study,we first developed a full two-dimensional(2D)hydrodynamic model for simulating surface water floods.We further evaluated the model performance with multisource data from flood incidents,including official reports and social media data.The model was tested in the cities of Baoji and Linyi,China,where two surface water flood events recently occurred and caused considerable losses and casualties.In total,350 localized flooding incidents were obtained for the two cities(220 in Baoji and 130 in Linyi)and 313 reports were retained after data cleaning(202 in Baoji and 111 in Linyi).Over 90%of the reported flood incidents fall in urban areas where water depths are predicted to be higher than 0.15 m.The results demonstrate that the model is able to derive the broad patterns of flood inundation at the city scale.The approach tested here could be applied to other flood-prone cities and future research could include water depth information for more robust model validation.展开更多
Using the Moderate Resolution Imaging Spectroradiometer-normalized difference vegetation index(NDVI) dataset,we investigated the patterns of spatiotemporal variation in vegetation coverage and its associated driving f...Using the Moderate Resolution Imaging Spectroradiometer-normalized difference vegetation index(NDVI) dataset,we investigated the patterns of spatiotemporal variation in vegetation coverage and its associated driving forces in the Qinling-Daba(Qinba) Mountains in 2000–2014.The Sen and Mann–Kendall models and partial correlation analysis were used to analyze the data,followed by calculation of the Hurst index to analyze future trends in vegetation coverage.The results of the study showed that(1) NDVI of the study area exhibited a significant increase in 2000–2014(linear tendency,2.8%/10a).During this period,a stable increase was detected before 2010(linear tendency,4.32%/10a),followed by a sharp decline after 2010(linear tendency,–6.59%/10a).(2) Spatially,vegetation cover showed a "high in the middle and a low in the surroundings" pattern.High values of vegetation coverage were mainly found in the Qinba Mountains of Shaanxi Province.(3) The area with improved vegetation coverage was larger than the degraded area,being 81.32% and 18.68%,respectively,during the study period.Piecewise analysis revealed that 71.61% of the total study area showed a decreasing trend in vegetation coverage in 2010–2014.(4) Reverse characteristics of vegetation coverage change were stronger than the same characteristics on the Qinba Mountains.About 46.89% of the entire study area is predicted to decrease in the future,while 34.44% of the total area will follow a continuously increasing trend.(5) The change of vegetation coverage was mainly attributed to the deficit in precipitation.Moreover,vegetation coverage during La Nina years was higher than that during El Nino years.(6) Human activities can induce ambiguous effects on vegetation coverage: both positive effects(through implementation of ecological restoration projects) and negative effects(through urbanization) were observed.展开更多
Freeze-thaw erosion is the third largest soil erosion type after water erosion and wind erosion. Restricted by many factors, few researches on freeze-thaw erosion have so far been done at home and abroad, especially t...Freeze-thaw erosion is the third largest soil erosion type after water erosion and wind erosion. Restricted by many factors, few researches on freeze-thaw erosion have so far been done at home and abroad, especially those on the assessment method of freeze-thaw erosion. Based on the comprehensive analysis of impact factors of free-thaw erosion, this paper chooses six indexes, including the annual temperature range, annual precipitation, slope, aspect, vegetation and soil, to build the model for relative classification of freeze-thaw erosion using weighted and additive methods, and realizes the relative classification of the freeze-thaw erosion in Tibet with the support of GIS software. Then a synthetic assessment of freeze-thaw erosion in Tibet has been carried out according to the relative classification result. The result shows that the distribution of freeze-thaw eroded area is very extensive in Tibet, accounting for 55.3% of the total local land area; the spatial differentiation of freeze-thaw erosion with different intensities is obvious; and the difference in distribution among different regions is also obvious.展开更多
This paper examines the changing regional distribution of grain production in China. Based on the analysis of data from county statistics for the period 2000-2003, major differences in the main grain-output regions in...This paper examines the changing regional distribution of grain production in China. Based on the analysis of data from county statistics for the period 2000-2003, major differences in the main grain-output regions in China can be observed. The main grain-producing areas have shifted from the south to the north of China. New grain production regions have been also added to westem China since the late 1990s. The per capita grain consumption in one third of China＇s main grain-producing counties has fallen below 400 kg; most of these areas are located in southern China. In the new millennium, Northeast China, the central-south North China, and the add and semi-arid regions of Northwest China produced three quarters of the surplus grains. Most of these areas are located in regions susceptible to environmental change. The amount of grain production in these regions shows high fluctuations. It is argued here that fi.trther studies of recent environmental changes as well as a risk assessment of China＇s food security in main grain-output regions are needed.展开更多
China is one of the countries in the world that are most affected by natural disasters. In recent years, with global climate change and rapid socioeconomic development in the country, natural disaster risks have been ...China is one of the countries in the world that are most affected by natural disasters. In recent years, with global climate change and rapid socioeconomic development in the country, natural disaster risks have been increasing and economic losses and the population affected have shown a growing trend;catastrophic disasters have repeatedly ravaged China, causing major socioeconomic impacts.The Chinese government attaches great importance to disaster prevention, reduction, and relief. Developments in laws and regulations on natural disaster management in the past three decades have provided an improved legal framework for disaster prevention, reduction, and relief. China’s disaster relief is guided by the principle of people-centered, government-led, multilevel management, mutual support within social networks, and self-rescue of victims. Through the years, the government has been expanding the scope of disaster relief and increasing the level of assistance, strengthening integrated coordination mechanisms, and standardizing procedures for relief work. Disaster prevention, reduction, and relief mechanisms based on China’s situation, and with Chinese characteristics, have been established. Attention has also been given to capacity-building. Much effort has been made to implement disaster reduction projects and to improve early warning systems, emergency response, science and technological support, human resource development, and community disaster relief systems. Future disaster reduction efforts of the Chinese government will focus on alleviating the impact of natural disasters, coping with catastrophic disaster risks, harmonizing the relationship between humans and nature, and attaining sustainable development.展开更多
Elucidating the distribution of the grazing pressure requires an understanding of the grazing activities.In this study,we analyzed the grazing behavior of yaks in Three-RiverSource Region(TRSR)and identified the main ...Elucidating the distribution of the grazing pressure requires an understanding of the grazing activities.In this study,we analyzed the grazing behavior of yaks in Three-RiverSource Region(TRSR)and identified the main factors influencing the distribution of grazing intensity(GI)using trajectory data and remote sensing datasets.Our results revealed that a semi-resident transhumance strategy is employed in this region.The average grazing time(GT)of four GPS collars over the year was 11.84 h/day(N6),11.01 h/day(N11),9.25 h/day(N18),and 11.61 h/day(N24).GT was generally higher in warm seasons(summer and autumn)than in cold seasons(spring and winter).The average daily moving speed was found to be closely related to the pasture size of different herders and the seasons.Geodetector analysis identified the distance to camp(DOC)as the most important single factor influencing the distribution of GI,explaining up to 52%of the GI variations.However,relying solely on this factor may not accurately depict the actual GI distribution.When pairwise factors interacted,the explanatory power of the model increased,ranging from 34.55%to 63.26%.Our study highlights the importance of considering multiple factors when predicting grazing intensity,as grazing activities tend to cluster near settlements,but other factors may also be influential.展开更多
In the context of climate change and human activities,flood disasters in arid mountainous areas have become increasingly frequent,and seriously threatened the safety of people's lives and property.Rapid and accura...In the context of climate change and human activities,flood disasters in arid mountainous areas have become increasingly frequent,and seriously threatened the safety of people's lives and property.Rapid and accurate flash flood inundation modelling is an essential foundational research area,which can aid in the reduction of casualties and the minimization of disaster losses;however,this modelling is also very difficult,and models need to be urgently developed to address flash flood forecasting and warnings.The objective of this study is to construct a numerical modelling method for flash floods in drylands.Based on a 2D high-resolution flood numerical model(Flood Map-Hydro Inundation2D),we hindcasted the dynamic process of flash flooding and show the spatio-temporal characteristics of flash flood inundation for the“8·18”flash flood disaster that occurred in Datong county,Qinghai province.The results showed that the model output effectively agreed with the observed inundation after the event in terms of both spatial extent and temporal process.Extensive flooding mainly occurred between 00:00 and 01:00 on August 18,2022.Qingshan,Hejiazhuang and Longwo villages were affected most heavily.We further conducted model sensitivity analysis and found that the model was highly sensitive to both roughness and hydraulic conductivity in drylands,and the effect of hydraulic conductivity was more pronounced.Our study confirmed the good performance of our model for the simulation of flash flooding in arid areas and provides a potential method for flash flood assessment and management in arid areas.展开更多
Natural disasters cause considerable property damage and loss of life as well as destruction of ecosystem and natural resources. In the context of global change, extreme events are expected to increase in both frequen...Natural disasters cause considerable property damage and loss of life as well as destruction of ecosystem and natural resources. In the context of global change, extreme events are expected to increase in both frequency and intensity. To prevent natural disasters and mitigate the loss, we need to act quickly and effectively. It would be conducive to achieve sustainable economic development, reduce disaster vulnerabilities and risks, and build resilience through implementing effective measures of disaster prevention, preparedness, response, and recovery.展开更多
1 Introduction The Sendai Framework for Disaster Risk Reduction 2015–2030 shifts the focus from managing disasters to reducing risks.Such a shift requires a better understanding of risk in all its dimensions of envir...1 Introduction The Sendai Framework for Disaster Risk Reduction 2015–2030 shifts the focus from managing disasters to reducing risks.Such a shift requires a better understanding of risk in all its dimensions of environment,hazards,exposure,and vulnerability;a disaster risk governance that展开更多
After mastering the key technologies of manufacturing spaceborne Synthetic Aperture Radar(SAR),China’s SAR satellites have been successfully launched into space.As the only civil microwave satellite listed in the“Na...After mastering the key technologies of manufacturing spaceborne Synthetic Aperture Radar(SAR),China’s SAR satellites have been successfully launched into space.As the only civil microwave satellite listed in the“National High-resolution Earth Observation System Major Project,”the Gaofen-3(GF-3)01 satellite is the first C-band multi-polarization SAR satellite with a resolution of 1 m.GF-3 series satellites stand out among civil SAR satellites worldwide because of their high resolution,wide swath,high geometric radiation quality,multiple imaging modes,and long operation time.Taking GF-3 series satellites as an example,this study introduces the development of China’s civil SAR satellites,as well as their processing strategies and applications.The success of the GF-3 series satellites shows that China’s SAR remote sensing technology has stepped into a new era of high-quality and high-precision Earth observations.展开更多
Disaster damage assessment is an important basis for the objective assessment of the social impacts of disasters and for the planning of recovery and reconstruction. It is also an important research field with regard ...Disaster damage assessment is an important basis for the objective assessment of the social impacts of disasters and for the planning of recovery and reconstruction. It is also an important research field with regard to disaster mitigation and risk management. Quantitative assessment of physical damage refers to the determination of the physical damage state of the exposed elements in a disaster area, reflecting the aggregate quantities of damages. It plays a key role in the comprehensive damage assessment of major natural hazard-induced disasters. The National Disaster Reduction Center of China has established a technical work flow for the quantitative assessment of disaster physical damage using remote sensing data.This article presents a quantitative assessment index system and method that can be integrated with high-resolution remote sensing data, basic geographical data, and field survey data. Following the 2014 Ludian Earthquake in Yunnan Province, China, this work flow was used to assess the damage to buildings, roads, and agricultural and forest resources, and the assessment results were incorporated into the Disaster Damage Comprehensive Assessment Report of the 2014 Ludian Earthquake for the State Council of China. This article also outlines some possible improvements that can be addressed in future work.展开更多
The Environment and Disaster Reduction Satellite Constellation is a small satellite constellation developed by China for disaster monitoring.The two primary optical satellites,HJ-A and HJ-B,were successfully launched ...The Environment and Disaster Reduction Satellite Constellation is a small satellite constellation developed by China for disaster monitoring.The two primary optical satellites,HJ-A and HJ-B,were successfully launched in September 2008.The satellites carry a charge-coupled device,hyperspectral imager,and infrared scanner,and have the capability for wide coverage and rapid revisits in disaster reduction applications.Also scheduled to be launched is the HJ-C,which will carry synthetic aperture radar and have the ability to provide allweather observations at any time.A follow-up‘44’satellite constellation including four optical satellites and four radar satellites is in the works,to achieve the capability of quantitative,all-weather,all-time disaster forecasting,monitoring and assessment.The corresponding disaster reduction application system has a series of functions including remote sensing data processing,disaster monitoring and assessment,decision support,and user service and information distribution,which serves the whole process of disaster management.Since its construction has been carried out,the system has successfully dealt with several huge domestic and international natural disasters,and effectively improved scientific decision support.The follow-up system’s construction will integrate,update,and extend the original system to fulfill large-scale,quantitative,allweather disaster operation application needs.展开更多
文摘The National Disaster Reduction Center of China(NDRCC)(The Satellite Application Center for Disaster Reduction)of the Ministry of Civil Affairs(MCA)of the Peopled Repub-lic of China was established in 2002,and is a specialized agency under the Chinese Government.It is engaged in infor-mation service and decision-making assistance in support of comprehensive natural disaster management.
文摘China is one of countries with frequent natural disasters and serious disaster losses.In recent years,with the background of global climate change,the disaster risk in China grows continuously.As a high-tech means with large-scale,all-weather,all time and dynamic monitoring spatial and temporal changes of the Earth,satellite remote sensing technology has been widely
基金supported by National Bei Dou Special Project and National Science & Technology planning project of China (Grant No. 2014BAK12B04)
文摘To better improve the emergency communication and location-based services of disaster information reporting network for serious natural response and relieL disaster emergency the national natural disaster reduction application platform based on BeiDou navigation satellite system is constructed. The administrative distributed platform is integrated with BeiDou positioning and multiple communication ways so as to achieve main disaster reduction application services, including disaster information acquisition and monitoring, emergency relief for trapped people, on-site emergency relief command service, relief supplies＇ transportation monitoring, and disaster information publishing service. By the platform, serious disaster information reporting time may be reduced to one hour and the emergency decision-making information service for serious natural disasters can be effectively improved, and it will be helpful to provide technical references for the industrial application and promotion of BeiDou inte- grated disaster reduction.
文摘With the global climate changes,the situation in coping with the natural disasters has become more serious and complicated.Many countries in the world focus on improving the technical support capacity for
基金supported by the National Science Foundation of China (No. 41201553)the National Basic Research Program of China (No. 2013BAK05B02)
文摘This paper deals with the formative process of the Wenchuan earthquake disaster chain risk. Selected earthquake-landslides chain risk is critically evaluated by the probability of landslide displacement failure based on the Newmark's permanent-deformation model. In this context, a conceptual model of regional disaster chain risk assessment was proposed, in which the hazardformative environments sensitivity was the core factor as well as the main difference compared with single disaster risk assessment. The disaster chain risk is accumulation of primary disaster risk and the secondary disasters risks. Results derived from the Wenchuan case proved that the conceptual model was suitable for the disaster chain risk assessment, especially the sudden disaster chain. This experience would offer greater potential in application of conceptual model of disaster chain risk assessment, in the process of large-scale disaster risk governance.
基金supported by National Natural Science Foundation of China (Grant Nos. 41301593 and 41471428)the Arid Meteorology Science Foundation, CMA (IAM201407)the State Key Development Program for BasicResearch of China (Grant No. 2012CB955402)
文摘The East Asian monsoon has a tremendous impact on agricultural production in China. An assessment of the risk of drought disaster in maize-producing regions is therefore important in ensuring a reduction in such disasters and an increase in food security. A risk assessment model, EPIC（Environmental Policy Integrated Climate） model, for maize drought disasters based on the Erosion Productivity Impact Calculator crop model is proposed for areas with the topographic characteristics of the mountainous karst region in southwest China. This region has one of the highest levels of environmental degradation in China. The results showed that the hazard risk level for the maize zone of southwest China is generally high. Most hazard index values were between 0.4 and 0.5,accounting for 47.32% of total study area. However,the risk level for drought loss was low. Most of the loss rate was ＆lt;0.1, accounting for 96.24% of the total study area. The three high-risk areas were mainlydistributed in the parallel ridge–valley areas in the east of Sichuan Province, the West Mountain area of Guizhou Province, and the south of Yunnan Province.These results provide a scientific basis and support for the reduction of agricultural drought disasters and an increase in food security in the southwest China maize zone.
文摘Environment and disaster monitoring and forecasting small satellite constellation A and B satellites(HJ-1-A,B) are called "environment and disaster reduction satellites A and B" for short.The constellation adopts a 10:30LT sun-synchronous circular orbit,with orbit altitude of 649km.HJ1-A and HJ-1-B are distributed with a phase difference of 180° in the same orbital plane,so as to enhance the time resolution of earth observation.The satellites have orbit maintenance capability,the lifetime is 3 years.Both satellites adopt CAST968 platforms.Two wide-coverage multispectral CCD cameras with resolution 30m and width 700km,a super-spectral imager with resolution 100m and width 50km as well as a data transmission subsystem of 120Mbit/s are deployed on HJ-1-A,which also carries Ka communication testing equipment of Thailand.HJ-1-B has two wide-coverage multispectral CCD cameras(the same as satellite A),one infrared camera with resolution 150m and width 720km and a data transmission subsystem of 60Mbit/s.The coverage period of the wide-coverage multispectral CCD camera is 48 hours.The revisit period of super-spectral imager is 96 hours and the coverage period ofinfrared camera is 96 hours.
基金funded by the National Key R&D Program of China(No.2020YFC150071)partly supported by the Shaanxi Province Geoscience Big Data and Geohazard Prevention Innovation Team(2022)and the Research Funds for the Interdisciplinary Projects,CHU(No.300104240914)。
文摘0 INTRODUCTION.According to the China Earthquake Networks Center,an M6.8 earthquake struck Dingri County,Xizang Autonomous Region,China,on 7 January 2025 at 9:05 a.m.local time.The epicenter is located at 28.5°N,87.45°E,with a depth of~10 km.
基金supported by the National Natural Science Foundation of China(Grant Nos:42371076,42271089,42461160294)the Key Project of Shanghai Municipal Education Commission(Grant No:2024AI01006)Shanghai Pilot Program for Basic Research(Grant No:TQ20240209)。
文摘Urban areas are particularly vulnerable to surface water flooding in a changing environment.A large number of urban surface water flood models have been developed to derive flood inundations and support risk management.However,unlike fluvial and coastal flooding,urban pluvial flooding is often associated with shallow water and thus the model is difficult to validate with traditional monitoring data.In this study,we first developed a full two-dimensional(2D)hydrodynamic model for simulating surface water floods.We further evaluated the model performance with multisource data from flood incidents,including official reports and social media data.The model was tested in the cities of Baoji and Linyi,China,where two surface water flood events recently occurred and caused considerable losses and casualties.In total,350 localized flooding incidents were obtained for the two cities(220 in Baoji and 130 in Linyi)and 313 reports were retained after data cleaning(202 in Baoji and 111 in Linyi).Over 90%of the reported flood incidents fall in urban areas where water depths are predicted to be higher than 0.15 m.The results demonstrate that the model is able to derive the broad patterns of flood inundation at the city scale.The approach tested here could be applied to other flood-prone cities and future research could include water depth information for more robust model validation.
基金Major Project of High-resolution Earth Observation SystemBeijing Natural Science Foundation,No.8144052
文摘Using the Moderate Resolution Imaging Spectroradiometer-normalized difference vegetation index(NDVI) dataset,we investigated the patterns of spatiotemporal variation in vegetation coverage and its associated driving forces in the Qinling-Daba(Qinba) Mountains in 2000–2014.The Sen and Mann–Kendall models and partial correlation analysis were used to analyze the data,followed by calculation of the Hurst index to analyze future trends in vegetation coverage.The results of the study showed that(1) NDVI of the study area exhibited a significant increase in 2000–2014(linear tendency,2.8%/10a).During this period,a stable increase was detected before 2010(linear tendency,4.32%/10a),followed by a sharp decline after 2010(linear tendency,–6.59%/10a).(2) Spatially,vegetation cover showed a "high in the middle and a low in the surroundings" pattern.High values of vegetation coverage were mainly found in the Qinba Mountains of Shaanxi Province.(3) The area with improved vegetation coverage was larger than the degraded area,being 81.32% and 18.68%,respectively,during the study period.Piecewise analysis revealed that 71.61% of the total study area showed a decreasing trend in vegetation coverage in 2010–2014.(4) Reverse characteristics of vegetation coverage change were stronger than the same characteristics on the Qinba Mountains.About 46.89% of the entire study area is predicted to decrease in the future,while 34.44% of the total area will follow a continuously increasing trend.(5) The change of vegetation coverage was mainly attributed to the deficit in precipitation.Moreover,vegetation coverage during La Nina years was higher than that during El Nino years.(6) Human activities can induce ambiguous effects on vegetation coverage: both positive effects(through implementation of ecological restoration projects) and negative effects(through urbanization) were observed.
基金Key Basic Research Project of China, No.2004CCA03600
文摘Freeze-thaw erosion is the third largest soil erosion type after water erosion and wind erosion. Restricted by many factors, few researches on freeze-thaw erosion have so far been done at home and abroad, especially those on the assessment method of freeze-thaw erosion. Based on the comprehensive analysis of impact factors of free-thaw erosion, this paper chooses six indexes, including the annual temperature range, annual precipitation, slope, aspect, vegetation and soil, to build the model for relative classification of freeze-thaw erosion using weighted and additive methods, and realizes the relative classification of the freeze-thaw erosion in Tibet with the support of GIS software. Then a synthetic assessment of freeze-thaw erosion in Tibet has been carried out according to the relative classification result. The result shows that the distribution of freeze-thaw eroded area is very extensive in Tibet, accounting for 55.3% of the total local land area; the spatial differentiation of freeze-thaw erosion with different intensities is obvious; and the difference in distribution among different regions is also obvious.
基金National Natural Science Foundation of China, No.40571165 No.40271115
文摘This paper examines the changing regional distribution of grain production in China. Based on the analysis of data from county statistics for the period 2000-2003, major differences in the main grain-output regions in China can be observed. The main grain-producing areas have shifted from the south to the north of China. New grain production regions have been also added to westem China since the late 1990s. The per capita grain consumption in one third of China＇s main grain-producing counties has fallen below 400 kg; most of these areas are located in southern China. In the new millennium, Northeast China, the central-south North China, and the add and semi-arid regions of Northwest China produced three quarters of the surplus grains. Most of these areas are located in regions susceptible to environmental change. The amount of grain production in these regions shows high fluctuations. It is argued here that fi.trther studies of recent environmental changes as well as a risk assessment of China＇s food security in main grain-output regions are needed.
文摘China is one of the countries in the world that are most affected by natural disasters. In recent years, with global climate change and rapid socioeconomic development in the country, natural disaster risks have been increasing and economic losses and the population affected have shown a growing trend;catastrophic disasters have repeatedly ravaged China, causing major socioeconomic impacts.The Chinese government attaches great importance to disaster prevention, reduction, and relief. Developments in laws and regulations on natural disaster management in the past three decades have provided an improved legal framework for disaster prevention, reduction, and relief. China’s disaster relief is guided by the principle of people-centered, government-led, multilevel management, mutual support within social networks, and self-rescue of victims. Through the years, the government has been expanding the scope of disaster relief and increasing the level of assistance, strengthening integrated coordination mechanisms, and standardizing procedures for relief work. Disaster prevention, reduction, and relief mechanisms based on China’s situation, and with Chinese characteristics, have been established. Attention has also been given to capacity-building. Much effort has been made to implement disaster reduction projects and to improve early warning systems, emergency response, science and technological support, human resource development, and community disaster relief systems. Future disaster reduction efforts of the Chinese government will focus on alleviating the impact of natural disasters, coping with catastrophic disaster risks, harmonizing the relationship between humans and nature, and attaining sustainable development.
基金The Second Tibetan Plateau Scientific Expedition and Research,No.2019QZKK0603Strategic Priority Research Program of the Chinese Academy of Sciences,No.XDA20040201National Natural Science Foundation of China,No.41671104。
文摘Elucidating the distribution of the grazing pressure requires an understanding of the grazing activities.In this study,we analyzed the grazing behavior of yaks in Three-RiverSource Region(TRSR)and identified the main factors influencing the distribution of grazing intensity(GI)using trajectory data and remote sensing datasets.Our results revealed that a semi-resident transhumance strategy is employed in this region.The average grazing time(GT)of four GPS collars over the year was 11.84 h/day(N6),11.01 h/day(N11),9.25 h/day(N18),and 11.61 h/day(N24).GT was generally higher in warm seasons(summer and autumn)than in cold seasons(spring and winter).The average daily moving speed was found to be closely related to the pasture size of different herders and the seasons.Geodetector analysis identified the distance to camp(DOC)as the most important single factor influencing the distribution of GI,explaining up to 52%of the GI variations.However,relying solely on this factor may not accurately depict the actual GI distribution.When pairwise factors interacted,the explanatory power of the model increased,ranging from 34.55%to 63.26%.Our study highlights the importance of considering multiple factors when predicting grazing intensity,as grazing activities tend to cluster near settlements,but other factors may also be influential.
基金National Natural Science Foundation of China,No.41871164。
文摘In the context of climate change and human activities,flood disasters in arid mountainous areas have become increasingly frequent,and seriously threatened the safety of people's lives and property.Rapid and accurate flash flood inundation modelling is an essential foundational research area,which can aid in the reduction of casualties and the minimization of disaster losses;however,this modelling is also very difficult,and models need to be urgently developed to address flash flood forecasting and warnings.The objective of this study is to construct a numerical modelling method for flash floods in drylands.Based on a 2D high-resolution flood numerical model(Flood Map-Hydro Inundation2D),we hindcasted the dynamic process of flash flooding and show the spatio-temporal characteristics of flash flood inundation for the“8·18”flash flood disaster that occurred in Datong county,Qinghai province.The results showed that the model output effectively agreed with the observed inundation after the event in terms of both spatial extent and temporal process.Extensive flooding mainly occurred between 00:00 and 01:00 on August 18,2022.Qingshan,Hejiazhuang and Longwo villages were affected most heavily.We further conducted model sensitivity analysis and found that the model was highly sensitive to both roughness and hydraulic conductivity in drylands,and the effect of hydraulic conductivity was more pronounced.Our study confirmed the good performance of our model for the simulation of flash flooding in arid areas and provides a potential method for flash flood assessment and management in arid areas.
文摘Natural disasters cause considerable property damage and loss of life as well as destruction of ecosystem and natural resources. In the context of global change, extreme events are expected to increase in both frequency and intensity. To prevent natural disasters and mitigate the loss, we need to act quickly and effectively. It would be conducive to achieve sustainable economic development, reduce disaster vulnerabilities and risks, and build resilience through implementing effective measures of disaster prevention, preparedness, response, and recovery.
文摘1 Introduction The Sendai Framework for Disaster Risk Reduction 2015–2030 shifts the focus from managing disasters to reducing risks.Such a shift requires a better understanding of risk in all its dimensions of environment,hazards,exposure,and vulnerability;a disaster risk governance that
基金supported by the National Natural Science Foundation of China(NSFC)[grant number 41801397]National Key Research and Development Program of China[grant number 2018YFC0825803]+2 种基金the Key Research and Development Program of Hubei Province[grant number 2021BID009]the Natural Science Foundation of Liaoning Province[grant number 2020-BS-259]the Key Laboratory of Land Satellite Remote Sensing Application,Ministry of Natural Resources of the People’s Republic of China[grant number KLSMNR-202107]。
文摘After mastering the key technologies of manufacturing spaceborne Synthetic Aperture Radar(SAR),China’s SAR satellites have been successfully launched into space.As the only civil microwave satellite listed in the“National High-resolution Earth Observation System Major Project,”the Gaofen-3(GF-3)01 satellite is the first C-band multi-polarization SAR satellite with a resolution of 1 m.GF-3 series satellites stand out among civil SAR satellites worldwide because of their high resolution,wide swath,high geometric radiation quality,multiple imaging modes,and long operation time.Taking GF-3 series satellites as an example,this study introduces the development of China’s civil SAR satellites,as well as their processing strategies and applications.The success of the GF-3 series satellites shows that China’s SAR remote sensing technology has stepped into a new era of high-quality and high-precision Earth observations.
基金partially supported by the National Natural Science Foundation of China (Grant No. 41301485)the High Resolution Earth Observation System (National Science and Technology Major Project)the National High Technology Research and Development Program of China (Grant No. 2012AA121305)
文摘Disaster damage assessment is an important basis for the objective assessment of the social impacts of disasters and for the planning of recovery and reconstruction. It is also an important research field with regard to disaster mitigation and risk management. Quantitative assessment of physical damage refers to the determination of the physical damage state of the exposed elements in a disaster area, reflecting the aggregate quantities of damages. It plays a key role in the comprehensive damage assessment of major natural hazard-induced disasters. The National Disaster Reduction Center of China has established a technical work flow for the quantitative assessment of disaster physical damage using remote sensing data.This article presents a quantitative assessment index system and method that can be integrated with high-resolution remote sensing data, basic geographical data, and field survey data. Following the 2014 Ludian Earthquake in Yunnan Province, China, this work flow was used to assess the damage to buildings, roads, and agricultural and forest resources, and the assessment results were incorporated into the Disaster Damage Comprehensive Assessment Report of the 2014 Ludian Earthquake for the State Council of China. This article also outlines some possible improvements that can be addressed in future work.
文摘The Environment and Disaster Reduction Satellite Constellation is a small satellite constellation developed by China for disaster monitoring.The two primary optical satellites,HJ-A and HJ-B,were successfully launched in September 2008.The satellites carry a charge-coupled device,hyperspectral imager,and infrared scanner,and have the capability for wide coverage and rapid revisits in disaster reduction applications.Also scheduled to be launched is the HJ-C,which will carry synthetic aperture radar and have the ability to provide allweather observations at any time.A follow-up‘44’satellite constellation including four optical satellites and four radar satellites is in the works,to achieve the capability of quantitative,all-weather,all-time disaster forecasting,monitoring and assessment.The corresponding disaster reduction application system has a series of functions including remote sensing data processing,disaster monitoring and assessment,decision support,and user service and information distribution,which serves the whole process of disaster management.Since its construction has been carried out,the system has successfully dealt with several huge domestic and international natural disasters,and effectively improved scientific decision support.The follow-up system’s construction will integrate,update,and extend the original system to fulfill large-scale,quantitative,allweather disaster operation application needs.
