[Objective]The ecological vulnerability and landscape ecological risk of karst mountainous areas have increased as a result of enhanced disturbance of natural resources by human activities.This paper aimed to explore ...[Objective]The ecological vulnerability and landscape ecological risk of karst mountainous areas have increased as a result of enhanced disturbance of natural resources by human activities.This paper aimed to explore the characteristics of ecological risk evolution under different landscape patterns in the region,with a view to providing reference for land classification protection,sustainable use of resources and regional ecological risk optimization in karst mountainous areas.[Method]Taking Huangping County,a typical karst mountainous area,as an example,eight evaluation factors of natural and landscape patterns were selected to construct a landscape ecological risk evaluation model,to quantitatively explore the spatio-temporal evolution of landscape ecological risk and the trend of risk level transfer in the study area from^(2)010-2018,and to reveal the complex relationship between ecological risk and topography in karst mountainous areas.[Result]①From 2010 to 2018,land use types changed to different degrees,with the most amount of woodland transferred out(1627.37 hm^(2))and the most amount of construction land transferred in(1303.93 hm^(2));a total of 3552.31 hm^(2) of land was transferred,with a change ratio of 2.13%,and there was a significant conversion between construction land,arable land,and woodland.②From 2010 to 2018,the landscape ecological risk in the study area changed significantly,and the landscape ecological risk index decreased from 0.3441 to 0.1733,showing an upward and then downward trend;the landscape ecological risk of the whole region was dominated by low-risk and lower-risk zones,and the ecological risk level generally shifted from a high level to a low level,and the ecological environment was improved.③There was a negative correlation between ecological risk and topographic position,and high-risk zones were mainly distributed among low topographic zones;with the change of time,the advantage of risk level for the selection of topography was gradually weakened,and the influence of anthropogenic factors on the ecological risk of the landscape was becoming more and more prominent.[Conclusion]This paper can provide theoretical basis for land use optimization and ecological protection in karst mountainous areas.展开更多
The Fenglin and Fengcong landform units are considered to be an important representation for defining the degree of development of Karst landforms. However, these terrain features have been proven difficult to delinea...The Fenglin and Fengcong landform units are considered to be an important representation for defining the degree of development of Karst landforms. However, these terrain features have been proven difficult to delineate and extract automatically because of their complex morphology. In this paper, a new method for identifying the Fenglin and Fengcong landform units is proposed. This method consists of two steps:(1) terrain openness calculation and(2) toe line extraction. The proposed method is applied and validated in the Karst case area of Guilin by using ASTER GDEM with one arc-second resolution. The openness of both the positive and negative terrain and a threshold were used to extract toe lines for segmenting depressions and pinnacles in Fenglin and Fengcong landforms. A comparison between the extracted Fenglin and Fengcong landform units and their real units from high resolution images wascarried out to evaluate the capability of the proposed method. Results show the proposed method can effectively extract the Fenglin and Fengcong landform units, and has an overall accuracy of 93.28%. The proposed method is simple and easy to implement and is expected to play an important role in the automatic extraction of similar landform units in the Karst area.展开更多
The 20％ of population in the world live in karst environment, which forms a special system of man and land, i.e., the formation of karst terrain in which people involved. The material flow and energy flow are slow-sp...The 20％ of population in the world live in karst environment, which forms a special system of man and land, i.e., the formation of karst terrain in which people involved. The material flow and energy flow are slow-speed flows in natural karst environment, but they are accelerated by the function of scientific and technological advance in a social-karst environment, The dynamic coupling of two flows form a huge, non-equilibrated and open system,展开更多
The huge karst area of south China is about 550,000 square km in extent.The karst terrain displays a geomorphic transition as the terrain gradually descends about 2,000 meters over 700 km from the western Yunnan-Guizh...The huge karst area of south China is about 550,000 square km in extent.The karst terrain displays a geomorphic transition as the terrain gradually descends about 2,000 meters over 700 km from the western Yunnan-Guizhou Plateau(averaging 2,100 meters of elevation)to the eastern Guangxi Basin(averaging 110 meters of elevation).展开更多
500米口径球面射电望远镜(Five-hundred-meter Aperture Spherical radio Telescope,FAST)——“中国天眼”举世瞩目,是世界上最大的单口径射电望远镜。如果再建造几个FAST型大射电望远镜,开展联合观测,那么不仅可以进一步提高探测的灵...500米口径球面射电望远镜(Five-hundred-meter Aperture Spherical radio Telescope,FAST)——“中国天眼”举世瞩目,是世界上最大的单口径射电望远镜。如果再建造几个FAST型大射电望远镜,开展联合观测,那么不仅可以进一步提高探测的灵敏度,也可以提高分辨率,从而拓展射电天文研究领域,这正是当前中国射电天文科学家的期盼,FAST型大射电望远镜选址洼地地形搜寻就是为实现这一期盼而开展的前期研究。当前,可以共享的地形数据数字高程模型(digital elevation model,DEM)资源已经实现洲际覆盖,且有不同的地面分辨率供选择;计算机技术发展带来了地形数据DEM处理分析能力大大增强,处理技术不断创新,分析表达实现了可仿真。为此,通过比较分析阿雷西博射电望远镜(Arecibo radio telescope,Arecibo)和FAST望远镜工程结构尺度、台址岩溶洼地地形的形态特点,提出500 m口径望远镜的理想洼地地形条件;在评价分析网络共享DEM地形数据的分辨率和数据质量的基础上,总结认为省级区域大射电望远镜选址以30 m分辨率的ASTER_GDEMV3数据为宜;在贵州全省大型洼地地形搜寻研究中,开发了基于ArcGIS平台提取洼地地形特征参数和拟合填挖方、叠合剖面等定量分析专题模块,归纳了应用ArcGIS主要工具搭建专题模块的关键步骤。研究结果解决了省级区域大型岩溶洼地地形搜寻中的关键技术,并提出了在实际工作中需要注意的几个问题。展开更多
基金the National Natural Science Foundation of China(41661088)Project for Guizhou Province"High-level Innovative Talent Training Program‘Hundred’Level Talents"(QKHPTRC[2016]5674)Guizhou Science and Technology Plan Project(QKHZC[2023]GENERAL211).
文摘[Objective]The ecological vulnerability and landscape ecological risk of karst mountainous areas have increased as a result of enhanced disturbance of natural resources by human activities.This paper aimed to explore the characteristics of ecological risk evolution under different landscape patterns in the region,with a view to providing reference for land classification protection,sustainable use of resources and regional ecological risk optimization in karst mountainous areas.[Method]Taking Huangping County,a typical karst mountainous area,as an example,eight evaluation factors of natural and landscape patterns were selected to construct a landscape ecological risk evaluation model,to quantitatively explore the spatio-temporal evolution of landscape ecological risk and the trend of risk level transfer in the study area from^(2)010-2018,and to reveal the complex relationship between ecological risk and topography in karst mountainous areas.[Result]①From 2010 to 2018,land use types changed to different degrees,with the most amount of woodland transferred out(1627.37 hm^(2))and the most amount of construction land transferred in(1303.93 hm^(2));a total of 3552.31 hm^(2) of land was transferred,with a change ratio of 2.13%,and there was a significant conversion between construction land,arable land,and woodland.②From 2010 to 2018,the landscape ecological risk in the study area changed significantly,and the landscape ecological risk index decreased from 0.3441 to 0.1733,showing an upward and then downward trend;the landscape ecological risk of the whole region was dominated by low-risk and lower-risk zones,and the ecological risk level generally shifted from a high level to a low level,and the ecological environment was improved.③There was a negative correlation between ecological risk and topographic position,and high-risk zones were mainly distributed among low topographic zones;with the change of time,the advantage of risk level for the selection of topography was gradually weakened,and the influence of anthropogenic factors on the ecological risk of the landscape was becoming more and more prominent.[Conclusion]This paper can provide theoretical basis for land use optimization and ecological protection in karst mountainous areas.
基金supported by the National Natural Science Foundation of China (NO. 41601411, 41671389, 41571398, 41701449) Open Fund of State Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University (Grant No. 17S02) A Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions-PAPD (Grant No. 164320H101)
文摘The Fenglin and Fengcong landform units are considered to be an important representation for defining the degree of development of Karst landforms. However, these terrain features have been proven difficult to delineate and extract automatically because of their complex morphology. In this paper, a new method for identifying the Fenglin and Fengcong landform units is proposed. This method consists of two steps:(1) terrain openness calculation and(2) toe line extraction. The proposed method is applied and validated in the Karst case area of Guilin by using ASTER GDEM with one arc-second resolution. The openness of both the positive and negative terrain and a threshold were used to extract toe lines for segmenting depressions and pinnacles in Fenglin and Fengcong landforms. A comparison between the extracted Fenglin and Fengcong landform units and their real units from high resolution images wascarried out to evaluate the capability of the proposed method. Results show the proposed method can effectively extract the Fenglin and Fengcong landform units, and has an overall accuracy of 93.28%. The proposed method is simple and easy to implement and is expected to play an important role in the automatic extraction of similar landform units in the Karst area.
文摘The 20％ of population in the world live in karst environment, which forms a special system of man and land, i.e., the formation of karst terrain in which people involved. The material flow and energy flow are slow-speed flows in natural karst environment, but they are accelerated by the function of scientific and technological advance in a social-karst environment, The dynamic coupling of two flows form a huge, non-equilibrated and open system,
文摘The huge karst area of south China is about 550,000 square km in extent.The karst terrain displays a geomorphic transition as the terrain gradually descends about 2,000 meters over 700 km from the western Yunnan-Guizhou Plateau(averaging 2,100 meters of elevation)to the eastern Guangxi Basin(averaging 110 meters of elevation).
