Land reclamation is a process of ecosystem reconstruction, for which it is very important to keep co-adaptation between plants and the below ground habitat. In order to keep the co-adaptation among plant species, thic...Land reclamation is a process of ecosystem reconstruction, for which it is very important to keep co-adaptation between plants and the below ground habitat. In order to keep the co-adaptation among plant species, thickness of covering soil and medium of covering soil to establish a self-regulating ecosystem, the thickness of covering soil of land reclamation for plants in different living forms by synusia structure of plant below-ground habitat and medium of covering soil by ecological factors of plant below-ground habitat were studied. Synusia structure of plant below-ground habitat was recognized through investigation on structure and root of plant community, and ecological factors were determined through soil profile investigation. The thickness and medium of covering soil of land reclamation for the tree, the shrub and the herb were proposed.展开更多
To detect overlapped echoes due to the thin pavement layers,we present a thickness measurement approach for the very thin layer of pavement structures.The term "thin" is relative to the incident wavelength o...To detect overlapped echoes due to the thin pavement layers,we present a thickness measurement approach for the very thin layer of pavement structures.The term "thin" is relative to the incident wavelength or pulse.By means of independent component analysis of noisy signals received by a single radar sensor,the overlapped echoes can be successfully separated.Once the echoes from the top and bottom side of a thin layer have been separated,the time delay and the layer thickness determination follow immediately.Results of the simulation and real data verify the feasibility of the presented method.展开更多
The soil freezing and thawing process affects soil physical properties,such as heat conductivity,heat capacity,and hydraulic conductivity in frozen ground regions,and further affects the processes of soil energy,hydro...The soil freezing and thawing process affects soil physical properties,such as heat conductivity,heat capacity,and hydraulic conductivity in frozen ground regions,and further affects the processes of soil energy,hydrology,and carbon and nitrogen cycles.In this study,the calculation of freezing and thawing front parameterization was implemented into the earth system model of the Chinese Academy of Sciences(CAS-ESM)and its land component,the Common Land Model(CoLM),to investigate the dynamic change of freezing and thawing fronts and their effects.Our results showed that the developed models could reproduce the soil freezing and thawing process and the dynamic change of freezing and thawing fronts.The regionally averaged value of active layer thickness in the permafrost regions was 1.92 m,and the regionally averaged trend value was 0.35 cm yr–1.The regionally averaged value of maximum freezing depth in the seasonally frozen ground regions was 2.15 m,and the regionally averaged trend value was–0.48 cm yr–1.The active layer thickness increased while the maximum freezing depth decreased year by year.These results contribute to a better understanding of the freezing and thawing cycle process.展开更多
In recent decades,research of the Alps,Qinghai-Tibet Plateau,and Cordillera have made great progress in understanding the phenomenon of permafrost.For the most part,this has been made possible due to temperature monit...In recent decades,research of the Alps,Qinghai-Tibet Plateau,and Cordillera have made great progress in understanding the phenomenon of permafrost.For the most part,this has been made possible due to temperature monitoring.However,the permafrost parameters in an area of more than 2 million square km of the mountainous regions of northeast Asia,for the most part,remain a blank spot in the scientific community.Due to the lack and insufficiency of factual materials,in 2012 the P.I.Melnikov Permafrost Institute began to take temperature measurements in the upper part of the permafrost in the central part of the VerkhoyanKolyma uplands,namely the Suntar-Khayat ridge.The article describes the temperature characteristics of air,surface and rocks of the active layer in the range of heights from 850 to 1821 m,in various landscape and topographic elements.For the observation period from 2012 to 2019,we obtained information on temperatures in the soils of the active layer at depths of 1 m,3 m,4 m,and 5 m and also air and surface temperature parameters.The availability of data on automated monitoring of rock temperatures in the active layer and the upper horizons of the layer of annual heat rotations made it possible to substantiate the most typical conditions of the temperature conditions of the permafrost zone of the characterized region.The parameters of permafrost existence and development are in favorable conditions.This is shown in the analysis of temperature data of air,surface and active layer.Soil temperatures in the active layer of annual heat rotations are most clearly represented at a depth of 1 m.Currently,on the territory of the mountain regions of Eastern Siberia,there are no more such sites for monitoring the temperature regime of soils.Information on the permafrost parameters in the region will allow us to begin the process of creating new models or checking existing forecasts and the distribution of the temperature pattern.It will also make it possible to evaluate the response of sensitive and vulnerable frozen soils of mountain regions to climate change.展开更多
在抗震设计中,场地是指具有相似的反应谱特征的工程群体所在地,不仅仅是房屋基础下的一小块地基土。其范围相当于厂区、居民小区和自然村或不小于1.0 km 2的平面面积。结合场地的概念,通过对一些项目地基处理前后场地类别的分析,从地基...在抗震设计中,场地是指具有相似的反应谱特征的工程群体所在地,不仅仅是房屋基础下的一小块地基土。其范围相当于厂区、居民小区和自然村或不小于1.0 km 2的平面面积。结合场地的概念,通过对一些项目地基处理前后场地类别的分析,从地基处理对场地类别及特征周期的影响,提出了通过地基处理实现上部结构减震的方法。展开更多
文摘Land reclamation is a process of ecosystem reconstruction, for which it is very important to keep co-adaptation between plants and the below ground habitat. In order to keep the co-adaptation among plant species, thickness of covering soil and medium of covering soil to establish a self-regulating ecosystem, the thickness of covering soil of land reclamation for plants in different living forms by synusia structure of plant below-ground habitat and medium of covering soil by ecological factors of plant below-ground habitat were studied. Synusia structure of plant below-ground habitat was recognized through investigation on structure and root of plant community, and ecological factors were determined through soil profile investigation. The thickness and medium of covering soil of land reclamation for the tree, the shrub and the herb were proposed.
文摘To detect overlapped echoes due to the thin pavement layers,we present a thickness measurement approach for the very thin layer of pavement structures.The term "thin" is relative to the incident wavelength or pulse.By means of independent component analysis of noisy signals received by a single radar sensor,the overlapped echoes can be successfully separated.Once the echoes from the top and bottom side of a thin layer have been separated,the time delay and the layer thickness determination follow immediately.Results of the simulation and real data verify the feasibility of the presented method.
基金This work was jointly funded by the National Natural Science Foundation of China(Grant Nos.42205168,41830967,and 42175163)the Youth Innovation Promotion Association CAS(2021073)the National Key Scientific and Technological Infrastructure project“Earth System Science Numerical Simulator Facility”(EarthLab).
文摘The soil freezing and thawing process affects soil physical properties,such as heat conductivity,heat capacity,and hydraulic conductivity in frozen ground regions,and further affects the processes of soil energy,hydrology,and carbon and nitrogen cycles.In this study,the calculation of freezing and thawing front parameterization was implemented into the earth system model of the Chinese Academy of Sciences(CAS-ESM)and its land component,the Common Land Model(CoLM),to investigate the dynamic change of freezing and thawing fronts and their effects.Our results showed that the developed models could reproduce the soil freezing and thawing process and the dynamic change of freezing and thawing fronts.The regionally averaged value of active layer thickness in the permafrost regions was 1.92 m,and the regionally averaged trend value was 0.35 cm yr–1.The regionally averaged value of maximum freezing depth in the seasonally frozen ground regions was 2.15 m,and the regionally averaged trend value was–0.48 cm yr–1.The active layer thickness increased while the maximum freezing depth decreased year by year.These results contribute to a better understanding of the freezing and thawing cycle process.
基金supported by the Russian Science Fund under basic project No.IX.135.2“Geotemperature field and transformation of the permafrost zone of North Asia and mountainous regions of Central Asia”。
文摘In recent decades,research of the Alps,Qinghai-Tibet Plateau,and Cordillera have made great progress in understanding the phenomenon of permafrost.For the most part,this has been made possible due to temperature monitoring.However,the permafrost parameters in an area of more than 2 million square km of the mountainous regions of northeast Asia,for the most part,remain a blank spot in the scientific community.Due to the lack and insufficiency of factual materials,in 2012 the P.I.Melnikov Permafrost Institute began to take temperature measurements in the upper part of the permafrost in the central part of the VerkhoyanKolyma uplands,namely the Suntar-Khayat ridge.The article describes the temperature characteristics of air,surface and rocks of the active layer in the range of heights from 850 to 1821 m,in various landscape and topographic elements.For the observation period from 2012 to 2019,we obtained information on temperatures in the soils of the active layer at depths of 1 m,3 m,4 m,and 5 m and also air and surface temperature parameters.The availability of data on automated monitoring of rock temperatures in the active layer and the upper horizons of the layer of annual heat rotations made it possible to substantiate the most typical conditions of the temperature conditions of the permafrost zone of the characterized region.The parameters of permafrost existence and development are in favorable conditions.This is shown in the analysis of temperature data of air,surface and active layer.Soil temperatures in the active layer of annual heat rotations are most clearly represented at a depth of 1 m.Currently,on the territory of the mountain regions of Eastern Siberia,there are no more such sites for monitoring the temperature regime of soils.Information on the permafrost parameters in the region will allow us to begin the process of creating new models or checking existing forecasts and the distribution of the temperature pattern.It will also make it possible to evaluate the response of sensitive and vulnerable frozen soils of mountain regions to climate change.
文摘在抗震设计中,场地是指具有相似的反应谱特征的工程群体所在地,不仅仅是房屋基础下的一小块地基土。其范围相当于厂区、居民小区和自然村或不小于1.0 km 2的平面面积。结合场地的概念,通过对一些项目地基处理前后场地类别的分析,从地基处理对场地类别及特征周期的影响,提出了通过地基处理实现上部结构减震的方法。
