The Daurian Partridge(Perdix dauuricae) is a kind of hunting bird with high economic value.Genetic diversity and structure in the Daurian Partridge were studied by analyzing eight microsatellite loci in 23 populations...The Daurian Partridge(Perdix dauuricae) is a kind of hunting bird with high economic value.Genetic diversity and structure in the Daurian Partridge were studied by analyzing eight microsatellite loci in 23 populations found throughout the range of the species in China.The objectives were to evaluate the consequences on genetic diversity and differentiation of Daurian Partridge populations and to obtain a profound genetic insight for future management decisions and for effective measures to protect and exploit Daurian Partridges.The results showed that microsatellites were polymorphic in all Daurian Partridge populations,with a high level of genetic diversity over all the loci,especially in the Qaidam Basin populations which have the highest level of diversity.Significant genetic divergence was observed among different groups as well as between populations within the same group;most pairwise FST values were highly significant.Both phylogenetic trees and Bayesian clustering analyses revealed clear differentiation among the 23 populations of the Daurian Partridge,which were classified into two genetically differentiated groups.A bottleneck analysis indicated that Daurian Partridge populations have experienced a recent bottleneck.Our study argues that the Qaidam populations,North China populations,JN population,ZJC population,and Liupan Mountain populations should be paid special attention in order to retain adequate population sizes for maintaining genetic diversity.展开更多
Although a growing number of both sequence-based and microsatellite nuclear loci have been used to infer genetic structures, their relative efficiencies remain poorly understood. In our study, we used the Green-backed...Although a growing number of both sequence-based and microsatellite nuclear loci have been used to infer genetic structures, their relative efficiencies remain poorly understood. In our study, we used the Green-backed Tit (Parus monticolus) to explore the resolving ability of these two types of markers. The south-western and central mitochondrial DNA (mtDNA) phylogroups were divergent to some extent in sequence-based nuclear data, while mixed together in microsatellites data. The F ST values among clades were about four times lower in microsatellite loci than those in sequence-based nuclear loci. We are of the opinion that size homoplasy may have contributed to the inability of microsatellites to uncover differentiation. Our results suggest that sequence-based nuclear loci outperformed microsatellite loci in detecting population structures, especially those focused on populations with large effective population sizes. There was no significant correlation between F ST values and allelic size variability, which suggested that the efficiency of microsatellite loci in detecting genetic structure may be independent of their polymorphism. F ST is better than R ST in detecting intraspecific divergence due to the high variance of R ST . In agreement with sequence-based nuclear loci, microsatellite loci did resolve the genetic distinctness of the Taiwan Residents phylogroup. The genetic differentiation between the Taiwan Residents and continental clades may involve allopatric divergence without gene flow.展开更多
The poor distribution of meteorological stations results in a limited understanding of the precipitation pattern in the Tianshan Mountains. The spatial patterns of precipitation over the mid Tianshan Mountains were ch...The poor distribution of meteorological stations results in a limited understanding of the precipitation pattern in the Tianshan Mountains. The spatial patterns of precipitation over the mid Tianshan Mountains were characterized based on the TRMM 3B43 monthly precipitation data. By comparing satellite estimates with observed data, it shows that TRMM 3B43 data underestimate the precipitation in mountain region. Regression models were developed to improve the TRMM 3B43 data, using geographic location and topographic variables extracted from DEM using GIS technology. The explained variance in observed precipitation was improved from 64% (from TRMM 3B43 products alone) to over 82% and the bias reduced by over 30% when location and topographic variables were added. We recalculated all the TRMM 3B43 monthly precipitation grids for the period 1998 to 2009 using the best regression models, and then studied the variation patterns of precipitation over the mid Tianshan Mountains. The results are well explained by a general understanding of the patterns of precipitation and orographic effects. This indicated that the Tianshan Mountains strongly influences the amount and distribution of precipitation in the region. This is highlighted by the confinement of the precipitation maxima to the windward (northern slope). And complex vertical changes in the provenance and distribution of precipitation, like that a negative increasing rate of precipitation in the vertical direction exists in the north but does not in south. The results have also revealed large gradients and different patterns in seasonal precipitation that are not simply related to elevation, the distribution of precipitation may also be affected by other seasonal factors such as the sources of moist air, wind direction and temperature.展开更多
With the rapid development of space technology,earth observation tech nology and sky observatory technolo-gy,they have played a more and more im portant part in monitoring and predi cting of earthquakes and volcanoes ...With the rapid development of space technology,earth observation tech nology and sky observatory technolo-gy,they have played a more and more im portant part in monitoring and predi cting of earthquakes and volcanoes i n the terres-trial land.In recent years,the rela ted agencies have done the experimen ts and researches on monitoring and p redicting of earthquakes and volcanoes in the forewarning period by means of many appr oaches,such as satellite thermal in frared re-mote sensing(TIRS),Global Positioning System(GPS),differential interferometric syn thesis aperture radar(D-INSAR),astronomical time-latitude residual anomaly,and Geographic Information Systems (GIS),etc.A quite large number of re-search foundation has been built in t he fundamental theories and applica tion methods.The experiments and re searches have shown that these technology is e fficient methods for high frequency crust movement.If the existed separate scientific forces and results are possibly asse mbled together to form a more complete integration monitoring system wit h the combina-tion of space,sky observation,grou nd,deep geology and macro anomaly,i t will come into a new stage of monitoring and predicting of earthquakes and volca nic eruptions.展开更多
Shadow is one of the major problems in remotely sensed imagery which hampers the accuracy of information extraction and change detection.In these images,shadow is generally produced by different objects,namely,cloud,m...Shadow is one of the major problems in remotely sensed imagery which hampers the accuracy of information extraction and change detection.In these images,shadow is generally produced by different objects,namely,cloud,mountain and urban materials.The shadow correction process consists of two steps:detection and de-shadowing.This paper reviews a range of techniques for both steps,focusing on urban regions(urban shadows),mountainous areas(topographic shadow),cloud shadows and composite shadows.Several issues including the problems and the advantages of those algorithms are discussed.In recent years,thresholding and recovery techniques have become important for shadow detection and de-shadowing,respectively.Research on shadow correction is still an important topic,particularly for urban regions(in high spatial resolution data) and mountainous forest(in high and medium spatial resolution data).Moreover,new algorithms are needed for shadow correction,especially given the advent of new satellite images.展开更多
Monitoring forest disturbances is important for understanding changes in ecosystems. The 1986 Typhoon Vera was a serious disturbance that severely impacted the forest ecosystems of Changbai Mountain National Nature Re...Monitoring forest disturbances is important for understanding changes in ecosystems. The 1986 Typhoon Vera was a serious disturbance that severely impacted the forest ecosystems of Changbai Mountain National Nature Reserve. Although the typhoon disturbance occurred more than two decades ago, the effects of the typhoon still remain within the study area. Few studies have focused on mapping and assessing disturbances across broad spatial and temporal scales. For this study, we first generated a map of forest composition prior to the typhoon disturbance, which served as a baseline data for the extraction of disturbed area. Then, the Disturbance Index(DI) method was tested for mapping the extent and magnitude of disturbance in the study area by applying a Tasseled Cap transformation to the Landsat imagery. The Landsatbased DI method estimated that an area of 13,764.78 ha of forest was disturbed by the typhoon. Based on visual assessments, these results correspond closely with the reference map derived from ground surveys. These results also revealed the influence of local topographic features on the distribution of windthrow areas. Windthrow areas were more pronounced inareas with elevations ranging from 1,000 to 2,000 m, slopes of less than 10 degrees, and southwestern to northwestern aspects. In addition, the relatively long(25 years) post-typhoon recovery period assessed by this study provided a more comprehensive analysis of the dynamics of forest recovery processes over time. Windthrow areas did not recover immediately after the typhoon, likely due to forest management practices enacted at the time. So far, forest recovery has proceeded more rapidly at elevations below 1,400 m, particularly on western slopes within the study area. Finally, a time series of DI values within the study period suggests a secondary disturbance may have occurred between 2000 and 2001.展开更多
Based on Coulomb static stress variation, the stress trigging action of the Mani ( M S 7 9, Nov. 1997) earthquake on the West Kunlun Mountains Pass ( M S 8 1, Nov. 2001) earthquake is researched. Results of different ...Based on Coulomb static stress variation, the stress trigging action of the Mani ( M S 7 9, Nov. 1997) earthquake on the West Kunlun Mountains Pass ( M S 8 1, Nov. 2001) earthquake is researched. Results of different source mechanism resolutions show that a 10 -3 MPa Coulomb stress due to the Mani earthquake was added to the fracture fault of the Kunlun earthquake, and this may shift the broken date to about 10 years earlier, and infer that the stress level in the crust is not low. Comparing the relationship between strong earthquake strength and frequency and earth rotation change, it is shown that the strength’s decrease and the variation period’s shortening of earth rotation are important controlling factors on strong earthquake activity. This great event with M S =8 1 took place probably due to a gradual strengthening background of regional stress field within the Qinghai_Xizang block in the period of acceleration of change of day’s length and stress triggering from the Mani earthquake.展开更多
To develop Martian soil simulant,basalts of the Chahar volcanic group in Wulanchabu,Inner Mongolia,China were selected as the simulant initial materials,which were ground and sorted to a predetermined particle size ra...To develop Martian soil simulant,basalts of the Chahar volcanic group in Wulanchabu,Inner Mongolia,China were selected as the simulant initial materials,which were ground and sorted to a predetermined particle size ratio,and small amounts of magnetite and hematite were added.The main phases of NEU Mars-1 simulant were plagioclase,augite and olivine.The glass transition and crystallization temperatures of NEU Mars-1 were 547.8 and 795.7°C,respectively.The complex dielectric constant,magnetic conductivity(0.99-1.045),and dielectric loss tangent angles(0.0025-0.030)of NEU Mars-1 were all stable in the frequency range of 2-18 GHz.Mossbauer spectroscopy results showed that the mass ratio of Fe2+to Fe3+in the simulant was 77.6:22.4.The NEU Mars-1 Martian soil simulant demonstrated particle size ratio,chemical composition,phase composition,thermal stability,and dielectric property similar to Martian soil,and can be used as the substitute material to extract oxygen and metals with in-situ resource utilization technologies.展开更多
At 5 am 24 th June 2017, a catastrophic landslide hit Xinmo Village, Maoxian County, Sichuan Province, China. The slide mass rushed down from an altitude of 3400 m and traveled 2700 m in a high velocity. The 13 millio...At 5 am 24 th June 2017, a catastrophic landslide hit Xinmo Village, Maoxian County, Sichuan Province, China. The slide mass rushed down from an altitude of 3400 m and traveled 2700 m in a high velocity. The 13 million m^3 deposition buried the whole village and caused about 100 deaths. The source area of the landslide is located in a high steep slope, average slope angle is 40o and maximal angle is 65o. The strata are interbedded Triassic Zagunao Formation metamorphic sandstone and slate with the dip slope angle of 45°. Based on high-resolution satellite remote sensing image, UAV image, DEM data, and field investigation, failure mechanism, travel features, and deposit characteristics were analyzed. The results showed that this landslide was influenced by Songpinggou Fault zone. According to the topography before the failure, the landslide is located in the back scarp of an antecedent landslide induced by Diexi Earthquake in 1933. The bedding slope provided potential rupture surface. Historical seismic activities and long-term gravitational deformation caused rock mass accumulated damages. Weathering and precipitation weakened the rock mass and finally induced shearing and tension failure. A huge block detached from the top rock slope, pushed the past landslide deposits in the middle part, rushed out of the slope bottom in a high velocity and buried the Xinmo Village. The rapid movement entrained and brought the soil into the Songping Gully which recoiled with and bounced back from the opposite mountain.展开更多
A total of seventeen caprine microsatellite markers were used on 169 goats to investigate genetic diversity of eight Cameroon native goat populations and to assess genetic differentiation with the East African small g...A total of seventeen caprine microsatellite markers were used on 169 goats to investigate genetic diversity of eight Cameroon native goat populations and to assess genetic differentiation with the East African small goat. All microsatellites showed a high polymorphic content (PIC) of more than 0.5 in almost all ecotypes. These microsatellite markers were useful for native goat ecotypes variability assessment. Expected heterozygosity of all ecotypes was above 0.5, varying from 0.2 to 0.7. Only goats from Eastern rainforest ecotype deviated from Hardy-Weinberg equilibrium test (P 〉 0.001). Although geographic distribution was a good indication of differentiation, there appeared a tendency of genetic exchange between various ecotypes in Cameroon native goats.展开更多
The presentation describes the methods and shows the results of GLOFs' danger estimation in lie and Zhetysu Alatau ranges (Kazakhstan). The catalogues of glacial lakes were made following the results of satellite i...The presentation describes the methods and shows the results of GLOFs' danger estimation in lie and Zhetysu Alatau ranges (Kazakhstan). The catalogues of glacial lakes were made following the results of satellite images processing. The catalogue contains the data of 186 glacial lakes in lle Alatau and 577 lakes in Zhetysu Alatau. According to the bathymetric data of 35 glacial lakes the dependences of volume on lake's area for proglacial and moraine lakes were developed and lake's volumes were calculated. There are 32 lakes in Ile Alatau and 110 lakes in Zhetysu Alatau with water volume more than 100,000 m3. The most hazardous lakes have the following characteristics: 1) the lake volume exceeds 100,000 m3, (2) the lake is proglacial, (3) the dam is a young moraine with an ice core, (4) there are sites with the steep of more than 15° spreading for more than 500 m down the valley, and (5) there are important non-protected objects in the mudflows affected area. There are 14 the most hazardous glacial lakes with very high level of GLOF danger: 6 lakes in lie Alatau and 8 lakes in Zhetysu Alatau.展开更多
This paper presents the changes of landscape structure in the Demanovská Valley which ranks among the most valuable protected areas of Slovakia. The area was selected on the basis of changes associated with the r...This paper presents the changes of landscape structure in the Demanovská Valley which ranks among the most valuable protected areas of Slovakia. The area was selected on the basis of changes associated with the rapidly growing tourism industry and the rise of an important destination in the center of Low Tatras National Park, Slovakia. To document any changes, we visually interpreted data from aerial and satellite images in three periods(1949, 2007 and 2013) and for predicting future changes we used land use planning documentation. Interpreted data were analyzed using overlay analysis and landscape metrics. Results showed extensive changes in the landscape structure mainly connected with the development of tourism infrastructure. We also identified long-term changes whose causes stem from the transformation of society and forest management in the past. The dynamics and extent of these changes may increase in the future. We propose to stop future development of ski slopes and expansion of related infrastructure, to focus on sustainability and environmentally friendly operation of the existing ski resort and to invest a substantial portion of profits to support projects aimed to preserve surrounding lands and wildlife.展开更多
Nowadays the rising of opportunity cost of farm labor comes to the forefront of attention in China. In order to understand its impact on agricultural land-use structure, a theoretical framework of household economics ...Nowadays the rising of opportunity cost of farm labor comes to the forefront of attention in China. In order to understand its impact on agricultural land-use structure, a theoretical framework of household economics is formulated drawn on Low's model. Under the theoretical framework, the impact of the rising opportunity cost of on-farm on cropping structure is deduced in theory. And then, using statistic and survey data, taking mountain area of southern Ningxia as an example, the theoretical assumes are verified. The results show that the rise of opportunity cost of farm labor leads to less diversified cropping structure.展开更多
In general,topographic shadow may reduce performance of forest mapping over mountainous regions in remotely sensed images.In this paper,information in shadow was synthesized by using two filling techniques,namely,roif...In general,topographic shadow may reduce performance of forest mapping over mountainous regions in remotely sensed images.In this paper,information in shadow was synthesized by using two filling techniques,namely,roifill and imfill,in order to improve the accuracy of forest mapping over mountainous regions.These two methods were applied to Landsat Enhanced Thematic Mapper (ETM +) multispectral image from Dong Yang County,Zhejiang Province,China.The performance of these methods was compared with two conventional techniques,including cosine correction and multisource classification.The results showed that by applying filling approaches,average overall accuracy of classification was improved by 14 percent.However,through conventional methods this value increased only by 9 percent.The results also revealed that estimated forest area on the basis of shadow-corrected images by 'roifill' technique was much closer to the survey data compared to traditional algorithms.Apart from this finding,our finding indicated that topographic shadow was an accentuated problem in medium resolution images such as Landsat ETM+ over mountainous regions.展开更多
As the number and geometric intensity of visual satellites are susceptible to large slopes in open-pit mines, we propose integration of GPS/Pseudolites (PLs) positioning technology which can increase the number of vis...As the number and geometric intensity of visual satellites are susceptible to large slopes in open-pit mines, we propose integration of GPS/Pseudolites (PLs) positioning technology which can increase the number of visible satellites, strengthen the geometric intensity of satellites and provide a precision solution for slope deformation monitoring. However, the un-modeled systematic errors are still the main limiting factors for high precision baseline solution. In order to eliminate the un-modeled systematic error, the Empirical Mode Decomposition (EMD) theory is employed. The multi-scale decomposition and reconstruction architecture are defined here on the basis of the EMD theory and the systematic error mitigation model is demonstrated as well. A standard of the scale selection for the systematic error elimination is given in terms of the mean of the accumulated standardized modes. Thereafter, the scheme of the GPS/PLs baseline solution based on the EMD is suggested. The simulation and experiment results show that the precision factors (DOP) are reduced greatly when PLs is located suitably. The proposed scheme dramatically improves the reliability of ambiguity resolution and the precision of baseline vector after systematic error being eliminated, and provides an effective model for high precision slope deformation monitoring in open-pit mine.展开更多
Slope aspect has significant effect on the development and distribution of montane forest, especially in arid and semiarid regions. This paper, using SPOT5 images and 1:5o,ooo DEM, digitally extracts and analyzes the...Slope aspect has significant effect on the development and distribution of montane forest, especially in arid and semiarid regions. This paper, using SPOT5 images and 1:5o,ooo DEM, digitally extracts and analyzes the spatial information of montane coniferous forest (mainly Qinghai spruce), and thereby explores how the upper and lower limits and the altitudinal range of coniferous forest vary and how the area of coniferous forest is related with annual insolation with all aspects in the Helan Mountains. The results show that: 1) In the eastern flank, the lower limit of coniferous forest is between 1,6oo m and a,ooo m a.s.l., and the upper limit between 2,800 m and 3,ooo m a.s.1.; in the western flank, the lower limit of coniferous forest is between a,ooo m and 2,300 m a.s.l., and the upper limit between 9,80o m and 3,1oo m a.s.1.2) The altitudinal ranges of coniferous forest are 8o6-1,435 m, 438-1,14o m for eastern flank and western flank, respectively. 3) The area of coniferous forest takes on a normal distribution with aspect, and it has a close relationship with annual insolation. This distribution model developed in this paper quantitatively reveals the significant effect of slope aspect on the distribution of coniferous forest in arid and semi-arid land.展开更多
Contrary to the countries of northern coast, the forest formations on Southern and East coast of the Mediterranean are in regression. With the combined action of the ax, fire and pasture, these ecosystems are subjecte...Contrary to the countries of northern coast, the forest formations on Southern and East coast of the Mediterranean are in regression. With the combined action of the ax, fire and pasture, these ecosystems are subjected to a pressure of permanent degradation. Indeed, the degradation of the forest ecosystems represents one of the most important causes of reduction and erosion of the biodiversity in the world. The massif of Aur6s is located in the North-East of Algeria. The analysis of the spatiotemporal dynamics of this vulnerable vegetation is not approached yet. This study proposes a focus on the analysis of the dynamics of this vegetation and to study the factors of its degradation. For that, a methodological approach of diachronic follow-up between two dates was adopted by using any kind of old information sources (archives, aerial photographs, topographic maps) and recent (Images satellite of American Landsat and data of land). The results reveal a degradation of vegetable cover thus expressing a very thorough reduction of the formations forest replaced by herbaceous formations very sensitive and threatened by the overgrazing.展开更多
Through the development of more than 60 years, the hot spring tourism industry in China will confront with a situation of "innovative competition, standard development, and secondary upgrade". In this paper, from th...Through the development of more than 60 years, the hot spring tourism industry in China will confront with a situation of "innovative competition, standard development, and secondary upgrade". In this paper, from the perspective of product integrated marketing theory, by taking Lushan (Xingzi) hot spring as an example, the authors carry out an analysis on some problems in the development of Xingzi hot spring tourism products, propose the framework and model of the integrated development of hot spring health tourism products, and also provide some suggestions for the design of Xingzi hot spring health tourism routes.展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 30530130)
文摘The Daurian Partridge(Perdix dauuricae) is a kind of hunting bird with high economic value.Genetic diversity and structure in the Daurian Partridge were studied by analyzing eight microsatellite loci in 23 populations found throughout the range of the species in China.The objectives were to evaluate the consequences on genetic diversity and differentiation of Daurian Partridge populations and to obtain a profound genetic insight for future management decisions and for effective measures to protect and exploit Daurian Partridges.The results showed that microsatellites were polymorphic in all Daurian Partridge populations,with a high level of genetic diversity over all the loci,especially in the Qaidam Basin populations which have the highest level of diversity.Significant genetic divergence was observed among different groups as well as between populations within the same group;most pairwise FST values were highly significant.Both phylogenetic trees and Bayesian clustering analyses revealed clear differentiation among the 23 populations of the Daurian Partridge,which were classified into two genetically differentiated groups.A bottleneck analysis indicated that Daurian Partridge populations have experienced a recent bottleneck.Our study argues that the Qaidam populations,North China populations,JN population,ZJC population,and Liupan Mountain populations should be paid special attention in order to retain adequate population sizes for maintaining genetic diversity.
基金supported by the National Science Fund for Distinguished Young Scientists (No. 30925008)the Major International (Regional) Joint Research Project (No. 31010103901)+1 种基金the CAS-IOZ Innovation Program (KSCX2-EW-J-2) by a grant (No. O529YX5105) from the Key Laboratory of the Zoological Systematics and Evolution of the Chinese Academy of Sciences to F.M. Lei
文摘Although a growing number of both sequence-based and microsatellite nuclear loci have been used to infer genetic structures, their relative efficiencies remain poorly understood. In our study, we used the Green-backed Tit (Parus monticolus) to explore the resolving ability of these two types of markers. The south-western and central mitochondrial DNA (mtDNA) phylogroups were divergent to some extent in sequence-based nuclear data, while mixed together in microsatellites data. The F ST values among clades were about four times lower in microsatellite loci than those in sequence-based nuclear loci. We are of the opinion that size homoplasy may have contributed to the inability of microsatellites to uncover differentiation. Our results suggest that sequence-based nuclear loci outperformed microsatellite loci in detecting population structures, especially those focused on populations with large effective population sizes. There was no significant correlation between F ST values and allelic size variability, which suggested that the efficiency of microsatellite loci in detecting genetic structure may be independent of their polymorphism. F ST is better than R ST in detecting intraspecific divergence due to the high variance of R ST . In agreement with sequence-based nuclear loci, microsatellite loci did resolve the genetic distinctness of the Taiwan Residents phylogroup. The genetic differentiation between the Taiwan Residents and continental clades may involve allopatric divergence without gene flow.
基金supported by the 973 Program of China(Grant No. 2010CB951002)Natural Science Foundation of China (Grant No. 41130641)
文摘The poor distribution of meteorological stations results in a limited understanding of the precipitation pattern in the Tianshan Mountains. The spatial patterns of precipitation over the mid Tianshan Mountains were characterized based on the TRMM 3B43 monthly precipitation data. By comparing satellite estimates with observed data, it shows that TRMM 3B43 data underestimate the precipitation in mountain region. Regression models were developed to improve the TRMM 3B43 data, using geographic location and topographic variables extracted from DEM using GIS technology. The explained variance in observed precipitation was improved from 64% (from TRMM 3B43 products alone) to over 82% and the bias reduced by over 30% when location and topographic variables were added. We recalculated all the TRMM 3B43 monthly precipitation grids for the period 1998 to 2009 using the best regression models, and then studied the variation patterns of precipitation over the mid Tianshan Mountains. The results are well explained by a general understanding of the patterns of precipitation and orographic effects. This indicated that the Tianshan Mountains strongly influences the amount and distribution of precipitation in the region. This is highlighted by the confinement of the precipitation maxima to the windward (northern slope). And complex vertical changes in the provenance and distribution of precipitation, like that a negative increasing rate of precipitation in the vertical direction exists in the north but does not in south. The results have also revealed large gradients and different patterns in seasonal precipitation that are not simply related to elevation, the distribution of precipitation may also be affected by other seasonal factors such as the sources of moist air, wind direction and temperature.
文摘With the rapid development of space technology,earth observation tech nology and sky observatory technolo-gy,they have played a more and more im portant part in monitoring and predi cting of earthquakes and volcanoes i n the terres-trial land.In recent years,the rela ted agencies have done the experimen ts and researches on monitoring and p redicting of earthquakes and volcanoes in the forewarning period by means of many appr oaches,such as satellite thermal in frared re-mote sensing(TIRS),Global Positioning System(GPS),differential interferometric syn thesis aperture radar(D-INSAR),astronomical time-latitude residual anomaly,and Geographic Information Systems (GIS),etc.A quite large number of re-search foundation has been built in t he fundamental theories and applica tion methods.The experiments and re searches have shown that these technology is e fficient methods for high frequency crust movement.If the existed separate scientific forces and results are possibly asse mbled together to form a more complete integration monitoring system wit h the combina-tion of space,sky observation,grou nd,deep geology and macro anomaly,i t will come into a new stage of monitoring and predicting of earthquakes and volca nic eruptions.
基金Under the auspices of National Technology Research and Development Program of China(No.2006BAJ05A02)National Natural Science Foundation of China(No.31172023)
文摘Shadow is one of the major problems in remotely sensed imagery which hampers the accuracy of information extraction and change detection.In these images,shadow is generally produced by different objects,namely,cloud,mountain and urban materials.The shadow correction process consists of two steps:detection and de-shadowing.This paper reviews a range of techniques for both steps,focusing on urban regions(urban shadows),mountainous areas(topographic shadow),cloud shadows and composite shadows.Several issues including the problems and the advantages of those algorithms are discussed.In recent years,thresholding and recovery techniques have become important for shadow detection and de-shadowing,respectively.Research on shadow correction is still an important topic,particularly for urban regions(in high spatial resolution data) and mountainous forest(in high and medium spatial resolution data).Moreover,new algorithms are needed for shadow correction,especially given the advent of new satellite images.
基金sponsored by the "State Key Laboratory of Resources and Environmental Information System" and the "Fundamental Research Funds for the Central Universities" (No. 11SSXT134)
文摘Monitoring forest disturbances is important for understanding changes in ecosystems. The 1986 Typhoon Vera was a serious disturbance that severely impacted the forest ecosystems of Changbai Mountain National Nature Reserve. Although the typhoon disturbance occurred more than two decades ago, the effects of the typhoon still remain within the study area. Few studies have focused on mapping and assessing disturbances across broad spatial and temporal scales. For this study, we first generated a map of forest composition prior to the typhoon disturbance, which served as a baseline data for the extraction of disturbed area. Then, the Disturbance Index(DI) method was tested for mapping the extent and magnitude of disturbance in the study area by applying a Tasseled Cap transformation to the Landsat imagery. The Landsatbased DI method estimated that an area of 13,764.78 ha of forest was disturbed by the typhoon. Based on visual assessments, these results correspond closely with the reference map derived from ground surveys. These results also revealed the influence of local topographic features on the distribution of windthrow areas. Windthrow areas were more pronounced inareas with elevations ranging from 1,000 to 2,000 m, slopes of less than 10 degrees, and southwestern to northwestern aspects. In addition, the relatively long(25 years) post-typhoon recovery period assessed by this study provided a more comprehensive analysis of the dynamics of forest recovery processes over time. Windthrow areas did not recover immediately after the typhoon, likely due to forest management practices enacted at the time. So far, forest recovery has proceeded more rapidly at elevations below 1,400 m, particularly on western slopes within the study area. Finally, a time series of DI values within the study period suggests a secondary disturbance may have occurred between 2000 and 2001.
文摘Based on Coulomb static stress variation, the stress trigging action of the Mani ( M S 7 9, Nov. 1997) earthquake on the West Kunlun Mountains Pass ( M S 8 1, Nov. 2001) earthquake is researched. Results of different source mechanism resolutions show that a 10 -3 MPa Coulomb stress due to the Mani earthquake was added to the fracture fault of the Kunlun earthquake, and this may shift the broken date to about 10 years earlier, and infer that the stress level in the crust is not low. Comparing the relationship between strong earthquake strength and frequency and earth rotation change, it is shown that the strength’s decrease and the variation period’s shortening of earth rotation are important controlling factors on strong earthquake activity. This great event with M S =8 1 took place probably due to a gradual strengthening background of regional stress field within the Qinghai_Xizang block in the period of acceleration of change of day’s length and stress triggering from the Mani earthquake.
基金Project(2017YFC0805100)supported by the National Key R&D Program of ChinaProject(GUIKE AA18118030)supported by Guangxi Innovation-driven Development Program,ChinaProject(N172502003)supported by the Fundamental Research Funds for the Central Universities,China.
文摘To develop Martian soil simulant,basalts of the Chahar volcanic group in Wulanchabu,Inner Mongolia,China were selected as the simulant initial materials,which were ground and sorted to a predetermined particle size ratio,and small amounts of magnetite and hematite were added.The main phases of NEU Mars-1 simulant were plagioclase,augite and olivine.The glass transition and crystallization temperatures of NEU Mars-1 were 547.8 and 795.7°C,respectively.The complex dielectric constant,magnetic conductivity(0.99-1.045),and dielectric loss tangent angles(0.0025-0.030)of NEU Mars-1 were all stable in the frequency range of 2-18 GHz.Mossbauer spectroscopy results showed that the mass ratio of Fe2+to Fe3+in the simulant was 77.6:22.4.The NEU Mars-1 Martian soil simulant demonstrated particle size ratio,chemical composition,phase composition,thermal stability,and dielectric property similar to Martian soil,and can be used as the substitute material to extract oxygen and metals with in-situ resource utilization technologies.
基金partially supported by the National Science Foundation of China(Grant No.41572302)the Funds for Creative Research Groups of China(Grant No.41521002)
文摘At 5 am 24 th June 2017, a catastrophic landslide hit Xinmo Village, Maoxian County, Sichuan Province, China. The slide mass rushed down from an altitude of 3400 m and traveled 2700 m in a high velocity. The 13 million m^3 deposition buried the whole village and caused about 100 deaths. The source area of the landslide is located in a high steep slope, average slope angle is 40o and maximal angle is 65o. The strata are interbedded Triassic Zagunao Formation metamorphic sandstone and slate with the dip slope angle of 45°. Based on high-resolution satellite remote sensing image, UAV image, DEM data, and field investigation, failure mechanism, travel features, and deposit characteristics were analyzed. The results showed that this landslide was influenced by Songpinggou Fault zone. According to the topography before the failure, the landslide is located in the back scarp of an antecedent landslide induced by Diexi Earthquake in 1933. The bedding slope provided potential rupture surface. Historical seismic activities and long-term gravitational deformation caused rock mass accumulated damages. Weathering and precipitation weakened the rock mass and finally induced shearing and tension failure. A huge block detached from the top rock slope, pushed the past landslide deposits in the middle part, rushed out of the slope bottom in a high velocity and buried the Xinmo Village. The rapid movement entrained and brought the soil into the Songping Gully which recoiled with and bounced back from the opposite mountain.
文摘A total of seventeen caprine microsatellite markers were used on 169 goats to investigate genetic diversity of eight Cameroon native goat populations and to assess genetic differentiation with the East African small goat. All microsatellites showed a high polymorphic content (PIC) of more than 0.5 in almost all ecotypes. These microsatellite markers were useful for native goat ecotypes variability assessment. Expected heterozygosity of all ecotypes was above 0.5, varying from 0.2 to 0.7. Only goats from Eastern rainforest ecotype deviated from Hardy-Weinberg equilibrium test (P 〉 0.001). Although geographic distribution was a good indication of differentiation, there appeared a tendency of genetic exchange between various ecotypes in Cameroon native goats.
文摘The presentation describes the methods and shows the results of GLOFs' danger estimation in lie and Zhetysu Alatau ranges (Kazakhstan). The catalogues of glacial lakes were made following the results of satellite images processing. The catalogue contains the data of 186 glacial lakes in lle Alatau and 577 lakes in Zhetysu Alatau. According to the bathymetric data of 35 glacial lakes the dependences of volume on lake's area for proglacial and moraine lakes were developed and lake's volumes were calculated. There are 32 lakes in Ile Alatau and 110 lakes in Zhetysu Alatau with water volume more than 100,000 m3. The most hazardous lakes have the following characteristics: 1) the lake volume exceeds 100,000 m3, (2) the lake is proglacial, (3) the dam is a young moraine with an ice core, (4) there are sites with the steep of more than 15° spreading for more than 500 m down the valley, and (5) there are important non-protected objects in the mudflows affected area. There are 14 the most hazardous glacial lakes with very high level of GLOF danger: 6 lakes in lie Alatau and 8 lakes in Zhetysu Alatau.
基金the support of the Scientific Grant Agency of the Slovak Republic through the research grant:"Adaptation strategies to natural and social disturbancies in the forestlandscape"(no.2/0038/14)
文摘This paper presents the changes of landscape structure in the Demanovská Valley which ranks among the most valuable protected areas of Slovakia. The area was selected on the basis of changes associated with the rapidly growing tourism industry and the rise of an important destination in the center of Low Tatras National Park, Slovakia. To document any changes, we visually interpreted data from aerial and satellite images in three periods(1949, 2007 and 2013) and for predicting future changes we used land use planning documentation. Interpreted data were analyzed using overlay analysis and landscape metrics. Results showed extensive changes in the landscape structure mainly connected with the development of tourism infrastructure. We also identified long-term changes whose causes stem from the transformation of society and forest management in the past. The dynamics and extent of these changes may increase in the future. We propose to stop future development of ski slopes and expansion of related infrastructure, to focus on sustainability and environmentally friendly operation of the existing ski resort and to invest a substantial portion of profits to support projects aimed to preserve surrounding lands and wildlife.
基金support of research grants from the National Key Technology R&D Program(Grant No.2006BAB15B02)the National Natural Science Fund of China(Grant No.40971062 and 404801051)
文摘Nowadays the rising of opportunity cost of farm labor comes to the forefront of attention in China. In order to understand its impact on agricultural land-use structure, a theoretical framework of household economics is formulated drawn on Low's model. Under the theoretical framework, the impact of the rising opportunity cost of on-farm on cropping structure is deduced in theory. And then, using statistic and survey data, taking mountain area of southern Ningxia as an example, the theoretical assumes are verified. The results show that the rise of opportunity cost of farm labor leads to less diversified cropping structure.
基金supported by the funding from National Natural Science Foundation of China(Grant No 30671212)partially by NASA projects NNX08AH50G and G05GD49G at Michigan State University
文摘In general,topographic shadow may reduce performance of forest mapping over mountainous regions in remotely sensed images.In this paper,information in shadow was synthesized by using two filling techniques,namely,roifill and imfill,in order to improve the accuracy of forest mapping over mountainous regions.These two methods were applied to Landsat Enhanced Thematic Mapper (ETM +) multispectral image from Dong Yang County,Zhejiang Province,China.The performance of these methods was compared with two conventional techniques,including cosine correction and multisource classification.The results showed that by applying filling approaches,average overall accuracy of classification was improved by 14 percent.However,through conventional methods this value increased only by 9 percent.The results also revealed that estimated forest area on the basis of shadow-corrected images by 'roifill' technique was much closer to the survey data compared to traditional algorithms.Apart from this finding,our finding indicated that topographic shadow was an accentuated problem in medium resolution images such as Landsat ETM+ over mountainous regions.
基金supported by the Research Fund of State Key Laboratory of Coal Resources and Mine safety, China University of Mining & Technology (No.08KF07) the Doctoral Fund of Ministry of Education for Young Scholar (No.200802901516)+4 种基金the Natural Science Foundation of Jiangsu Province (No.BK2009099)the Special Foundation of NSFC-DEST (No.50810076)the National Natural Science Foundation of China (No.40774010)the National Natural Science Foundation for Young Scholar (No.40904004)the Doctoral Fund of Ministry of Education of China (No.200802900501)
文摘As the number and geometric intensity of visual satellites are susceptible to large slopes in open-pit mines, we propose integration of GPS/Pseudolites (PLs) positioning technology which can increase the number of visible satellites, strengthen the geometric intensity of satellites and provide a precision solution for slope deformation monitoring. However, the un-modeled systematic errors are still the main limiting factors for high precision baseline solution. In order to eliminate the un-modeled systematic error, the Empirical Mode Decomposition (EMD) theory is employed. The multi-scale decomposition and reconstruction architecture are defined here on the basis of the EMD theory and the systematic error mitigation model is demonstrated as well. A standard of the scale selection for the systematic error elimination is given in terms of the mean of the accumulated standardized modes. Thereafter, the scheme of the GPS/PLs baseline solution based on the EMD is suggested. The simulation and experiment results show that the precision factors (DOP) are reduced greatly when PLs is located suitably. The proposed scheme dramatically improves the reliability of ambiguity resolution and the precision of baseline vector after systematic error being eliminated, and provides an effective model for high precision slope deformation monitoring in open-pit mine.
基金supported by the Naional 973 project (2009CB421307) the National Natural Science Foundation of China (41030528 and 40971064)
文摘Slope aspect has significant effect on the development and distribution of montane forest, especially in arid and semiarid regions. This paper, using SPOT5 images and 1:5o,ooo DEM, digitally extracts and analyzes the spatial information of montane coniferous forest (mainly Qinghai spruce), and thereby explores how the upper and lower limits and the altitudinal range of coniferous forest vary and how the area of coniferous forest is related with annual insolation with all aspects in the Helan Mountains. The results show that: 1) In the eastern flank, the lower limit of coniferous forest is between 1,6oo m and a,ooo m a.s.l., and the upper limit between 2,800 m and 3,ooo m a.s.1.; in the western flank, the lower limit of coniferous forest is between a,ooo m and 2,300 m a.s.l., and the upper limit between 9,80o m and 3,1oo m a.s.1.2) The altitudinal ranges of coniferous forest are 8o6-1,435 m, 438-1,14o m for eastern flank and western flank, respectively. 3) The area of coniferous forest takes on a normal distribution with aspect, and it has a close relationship with annual insolation. This distribution model developed in this paper quantitatively reveals the significant effect of slope aspect on the distribution of coniferous forest in arid and semi-arid land.
文摘Contrary to the countries of northern coast, the forest formations on Southern and East coast of the Mediterranean are in regression. With the combined action of the ax, fire and pasture, these ecosystems are subjected to a pressure of permanent degradation. Indeed, the degradation of the forest ecosystems represents one of the most important causes of reduction and erosion of the biodiversity in the world. The massif of Aur6s is located in the North-East of Algeria. The analysis of the spatiotemporal dynamics of this vulnerable vegetation is not approached yet. This study proposes a focus on the analysis of the dynamics of this vegetation and to study the factors of its degradation. For that, a methodological approach of diachronic follow-up between two dates was adopted by using any kind of old information sources (archives, aerial photographs, topographic maps) and recent (Images satellite of American Landsat and data of land). The results reveal a degradation of vegetable cover thus expressing a very thorough reduction of the formations forest replaced by herbaceous formations very sensitive and threatened by the overgrazing.
文摘Through the development of more than 60 years, the hot spring tourism industry in China will confront with a situation of "innovative competition, standard development, and secondary upgrade". In this paper, from the perspective of product integrated marketing theory, by taking Lushan (Xingzi) hot spring as an example, the authors carry out an analysis on some problems in the development of Xingzi hot spring tourism products, propose the framework and model of the integrated development of hot spring health tourism products, and also provide some suggestions for the design of Xingzi hot spring health tourism routes.