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Dynamic model and performance analysis of landing buffer for bionic locust mechanism 被引量:5
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作者 Dian-Sheng Chen Zi-Qiang Zhang Ke-Wei Chen 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2016年第3期551-565,共15页
The landing buffer is an important problem in the research on bionic locust jumping robots, and the different modes of landing and buffering can affect the dynamic performance of the buffering process significantly. B... The landing buffer is an important problem in the research on bionic locust jumping robots, and the different modes of landing and buffering can affect the dynamic performance of the buffering process significantly. Based on an experimental observation, the different modes of landing and buffering are determined, which include the different numbers of landing legs and different motion modes of legs in the buffering process. Then a bionic locust mechanism is established, and the springs are used to replace the leg muscles to achieve a buffering effect. To reveal the dynamic performance in the buffering process of the bionic locust mechanism, a dynamic model is established with different modes of landing and buffering. In particular, to analyze the buffering process conveniently, an equivalent vibration dynamic model of the bionic locust mechanism is proposed.Given the support forces of the ground to the leg links, which can be obtained from the dynamic model, the spring forces of the legs and the impact resistance of each leg are the important parameters affecting buffering performance, and evaluation principles for buffering performance are proposed according to the aforementioned parameters. Based on the dynamic model and these evaluation principles, the buffering performances are analyzed and compared in different modes of landing and buffering on a horizontal plane and an inclined plane. The results show that the mechanism with the ends of the legs sliding can obtain a better dynamic performance. This study offers primary theories for buffering dynamics and an evaluation of landing buffer performance,and it establishes a theoretical basis for studies and engineering applications. 展开更多
关键词 Bionic locust mechanism landing and buffering dynamic model Buffering performance
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Metropolitan Housing Development in Urban Fringe Areas-A Case Study of Three Metropolitan Cities of South Africa: Johannesburg, Ekurhuleni and Tshwane
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作者 Aurobindo Ogra 《Journal of Civil Engineering and Architecture》 2024年第5期244-253,共10页
Purpose:The metropolitan cities of Johannesburg,Ekurhuleni and Tshwane play an important role in the economy of the Gauteng province in South Africa.The region constitutes to 22.4 percent of the total population of So... Purpose:The metropolitan cities of Johannesburg,Ekurhuleni and Tshwane play an important role in the economy of the Gauteng province in South Africa.The region constitutes to 22.4 percent of the total population of South Africa and has a strong presence and contributes in areas of manufacturing sector,financial and business services,retail and wholesale trade,etc.The rapid urban population,increase in the informal settlements and socio-economic opportunities has resulted in considerable urban sprawl in and around the urban fringe areas of these metropolitan cities.The urban fringe areas of these metros often come under the influence of rapid urbanization process and pressures.Coupled with the economical and potential land dynamics and lack of priority of spatial development guidelines,these areas attract rapid and haphazard development from communities and developers.Research Design/Methodology:This research is based on a qualitative approach through a comprehensive literature review that included content analysis of key documents on housing sector such as IDPs(Integrated Development Plans),Municipal Annual Reports,Growth Development Strategies,and among other sectoral documents on housing sector.Some of the key priority issues considered in the housing sector included:eradication of housing backlogs,spatial restructuring of housing,provision of choice in terms of location,tenure and housing typology.Findings:The current paper discusses the approaches of metropolitan housing development processes in three metropolitan cities of South Africa from Gauteng region,namely:Johannesburg,Ekurhuleni and Tshwane.The paper discusses the existing housing sectoral scenario along with the fringe areas in three cities with focus on:formal and informal settlements,housing segregation and the backlogs,current institutional arrangements,role of public private participation,and scope for alternate mechanisms.The paper concludes in discussion on sustainable development options for housing development in urban fringe areas. 展开更多
关键词 Metropolitan housing development urban fringe areas housing backlog informal settlements urban poor land dynamics housing infrastructure PPP(public private partnership)
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Monitoring Land Use Dynamics in Chanthaburi Province of Thailand Using Digital Remotely Sensed Images 被引量:12
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作者 SHENRUNPING I.KHEORUENROMNE 《Pedosphere》 SCIE CAS CSCD 2003年第2期157-164,共8页
A comprehensive method of image classification was developed for monitoring land use dynamics in Chanthaburi Province of Tailand. RS (Remote Sensing), GIS (Geographical Information System), GPS (Global Positioning Sys... A comprehensive method of image classification was developed for monitoring land use dynamics in Chanthaburi Province of Tailand. RS (Remote Sensing), GIS (Geographical Information System), GPS (Global Positioning System) and ancillary data were combined by the method which adopts the main idea of classifying images by steps from decision tree method and the hybridized supervised and unsupervised classification. An integration of automatic image interpretation, ancillary materials and expert knowledge was realized. Two subscenes of Landsat 5 Thematic Mapper (TM) images of bands 3, 4 and 5 obtained on December 15, 1992, and January 17, 1999, were used for image processing and spatial data analysis in the study. The overall accuracy of the results of classification reached 90%, which was verified by field check.Results showed that shrimp farm land, urban and traffic land, barren land, bush and agricultural developing area increased in area, mangrove, paddy field, swamp and marsh land, orchard and plantation, and tropical grass land decreased, and the forest land kept almost stable. Ecological analysis on the land use changes showed that more attentions should be paid on the effect of land development on ecological environment in the future land planning and management. 展开更多
关键词 image classification land use dynamics remote sensing tropical area
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Simulation on the dynamics of forest area changes in Northeast China 被引量:11
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作者 DENG Xiangzheng JIANG Qun'ou +2 位作者 ZHAN Jinyan HE Shujin LIN Yingzhi 《Journal of Geographical Sciences》 SCIE CSCD 2010年第4期495-509,共15页
There is plenty of forests in Northeast China which contributes a lot to the conservation of water and land resources, produces timber products, and provides habitats for a huge number of wild animals and plants. With... There is plenty of forests in Northeast China which contributes a lot to the conservation of water and land resources, produces timber products, and provides habitats for a huge number of wild animals and plants. With changes of socio-economic factors as well as the geophysical conditions, there are dramatic changes on the spatial patterns of forest area. In this sense, it is of great significance to shed light on the dynamics of forest area changes to find the underlining reasons for shaping the changing patterns of forest area in Northeast China. To explore the dynamics of forest area change in Northeast China, an econometric model is developed which is composed of three equations identifying forestry production, conversion from open forest to closed forest and conversion from other land uses to closed forest so as to explore the impacts on the forest area changes from demographic, social, economic, location and geophysical factors. On this basis, we employ the Dynamics of Land System (DLS) model to simulate land-use conversions between forest area and non-forest cover and the land-use conversions within the sub-classes of forest area for the period 2000-2020 under business as usual scenario, environmental protection scenario and economic growth scenario. The simulation results show that forest area will expand continuously and there exist various kinds of changing patterns for the sub-classes of forest area, for example, closed forest will expand continuously and open forest and shrub will decrease a little bit, while area of other forest will keep intact. The research results provide meaningful decision-making information for conserving and exploiting the forest resources and makJng out the planning for forestry production Jn the Northeast China region. 展开更多
关键词 forest area forestry production econometric model dynamics of land system Northeast China
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DYNAMIC CHARACTERISTICS OF PRESENT PRODUCTIVITY FOR CULTIVATED LAND IN THE FARNMING-PASTORAL ZONE OF INNER MONGOLIA 被引量:1
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作者 Wang Jing ’ai(Department of Resources and Environmental Science Beijing Normal University, Beijing 100875People’s Republic of China) 《Journal of Geographical Sciences》 SCIE CSCD 1995年第2期21-29,共9页
In this article, the distribution of cultivated land, the changes ofcultivated land productivity, and regional differentiation of the Change forpresent productivity in the Farming-Pastoral Zone, Inner Mongolia aredis... In this article, the distribution of cultivated land, the changes ofcultivated land productivity, and regional differentiation of the Change forpresent productivity in the Farming-Pastoral Zone, Inner Mongolia arediscussed. Then, the close relationship between dynamic characterlsticsdivision and atmospheric circulation systems is revealed. Finally, based ondynamic characteristics, four regions are divided, including thenortheastem area, the eastern area, the western area, and the middle area. 展开更多
关键词 Farming-Pastoral Zone present productivity cultivated land dynamic characteristics division
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Land Use and Land Cover Dynamics in the Urban Watershed of Kimemi River (Butembo/D.R.C) 被引量:2
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作者 Jonathan Ahadi Mahamba Gloire Kayitoghera Mulondi +1 位作者 Moïse Musubao Kapiri Walere Muhindo Sahani 《Journal of Geoscience and Environment Protection》 2022年第6期204-219,共16页
Changes in land use and land cover (LULC) influence hydrological processes in a watershed. This study analyses the dynamics of LULC in the Kimemi watershed from 1987 to 2021. GIS and remote sensing tools as well as la... Changes in land use and land cover (LULC) influence hydrological processes in a watershed. This study analyses the dynamics of LULC in the Kimemi watershed from 1987 to 2021. GIS and remote sensing tools as well as landscape pattern analysis were used to achieve this purpose. The results reveal that the LULC change is globally marked by an increase in the bare land and building at the expense of the low vegetation (grassland). Between 1987 and 2011, the bare land and buildings (Tg = 61.33%) and the woodland (Tg = 34.2%) classes increased, whereas the grassland class decreased (Tg = -39.5%). On the other hand, between 2011 and 2015, the bare land and building class still increased (Tg = 29.9%) while that of grassland and woodland decreased with Tg = -37.3% and Tg = -4.9%, respectively. Finally, the dynamics observed from 2015 to 2021 is marked by small changes between classes with Tg values of 2.1%, 1.9% and -8.9%, respectively, for the bare land and building, grassland and woodland classes, respectively. The main spatial transformation processes observed are creation and dissection for the bare land and building class, and the grassland class respectively. In particular, the woodland class underwent the creation process between 1987 and 2011 before undergoing attrition (2011-2015-2021). Reduced vegetated areas give rise to new planning decisions to mitigate the hydrological risks that could result from this situation. 展开更多
关键词 Land Use and Land Cover dynamics WATERSHED Kimemi River Butembo
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Dynamic Change Analysis of Urban Green Land in Jinan City Based RS and Geo-information Tupu 被引量:2
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作者 XU Qiu-xiao 《Asian Agricultural Research》 2011年第1期90-92,共3页
The three-period (1995, 1998 and 2003) remote sensing images in Jinan City, China are selected. And the information of green land, construction land, woodland and water body is extracted by using the image processing ... The three-period (1995, 1998 and 2003) remote sensing images in Jinan City, China are selected. And the information of green land, construction land, woodland and water body is extracted by using the image processing module of remote-sensing software and computerized interpretation module. Both the change table and transfer matrix table of land use area are analyzed by modeling module of remote-sensing software. Then, the Geo-information Tupu is obtained; and the temporal and spatial variation of land use in Jinan City is monitored and analyzed by Geo-information Tupu and transfer matrix. Result shows that land use structure change of Jinan City in the years 1995-1998 shows a transformation from green land to construction land. Area of green land circulating into construction land reaches 62.27 square kilometers, accounting for 25.84% of the initial green land. In the year 1998, areas of woodland and green land are reduced due to the urban expansion of Jinan City. However, with the enhancement of people's awareness of environmental protection, areas of woodland and green land gradually increase in the year 2003, which are still less than those in the year 1995. 展开更多
关键词 Remote sensing Geo-information Tupu dynamic change of the green land Jinan City China
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International Conference on Land Use / Cover Change Dynamics
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《Journal of Geographical Sciences》 SCIE CSCD 2001年第1期121-,共1页
Organized by: Beijing Normal University, National Natural Science Foundation of China Hosted by: Institute of Resources Science, Beijing Normal UniversityKey Laboratory of Environmental Change and Natural Disaster, Mi... Organized by: Beijing Normal University, National Natural Science Foundation of China Hosted by: Institute of Resources Science, Beijing Normal UniversityKey Laboratory of Environmental Change and Natural Disaster, Ministry of Education of ChinaTopics:1) Detecting and monitoring LUCC2) Temporal-spatial characteristics in LUCC3) Driving model for LUCC4) Forecasting and modeling LUCC 5) Phenological and biochemical response on LUCC6) Regional LUCC and microclimate 7) LUCC in the context of global change8) Impact of global change on the sustainable land-use modelingAbstract submission: The official language of this conference is English. We invite papers written in English and an abstract of less than one page of standard A4 size to the Conference Secretariat by Apr 15, 2001. Registration Fee: 280 US$ (300 US$ after July 15, 2001)Add:No. 19, Xinjiekouwai Street, 100875, Institute of Resources Science, Beijing Normal University, Beijing, ChinaTel:86-10-62207656 or 62209024 Fax:010-62208178http:// 202.112.93.50/LUCCD2001/index.htmlE-mail: Pwang@bnu.edu.cn Cyh@bnu.edu. 展开更多
关键词 LUCCD’2001 First Circular Announcement International Conference on Land Use/Cover Change dynamics
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Drivers of Land Cover Dynamics for Pugu and Kazimuzumbwi Forest Reserves in Kisarawe, Tanzania
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作者 Makarius Victor Mdemu Marco Mathias Burra 《Open Journal of Forestry》 2016年第5期348-360,共14页
Forests that are close to growing urban centres have been subject to constant deforestation and degradation from various factors. This study assesses the drivers of land cover dynamics in Pugu and Kazimzumbwi forest r... Forests that are close to growing urban centres have been subject to constant deforestation and degradation from various factors. This study assesses the drivers of land cover dynamics in Pugu and Kazimzumbwi forest reserves in the context of urban and peri-urban expansion of Dar es Salaam for the past three decades. The study adopted review of relevant literature and household survey from three settlements surrounding the forest reserves. One hundred and fifty (150) households were collected from Buyuni, Chanika and Masaki in Ilala and Kisarawe and administered with semi-structured questionnaire to collect information on migration, use of forest products by communities and perception on climate change and variability. SPSS computer program was used to analyse the questionnaire data while tables and graphs were adopted for presentation of the results. Rural-urban and internal urban migration in Dar es Salaam was identified as one of the primary drivers of land cover dynamics in peri-urban areas and adjoining environments. The migration was intensified by push drivers which include urban growth, market of land and reliance on forest product among community members as source of their livelihoods. The increased rainfall variability accompanied with high temperature has contributed to frequent droughts which compromises rainfed agriculture. Thus, the successful conservation of the forest will require strengthened enforcement of protection measures supported with introduction of alternative livelihood strategies for majority of poor community members. 展开更多
关键词 Climate Change and Variability DRIVER Forest Reserve Land Cover dynamics PERI-URBAN
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A comparative assessment of gravitational field modeling methods for binary asteroid landing
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作者 Tongge Wen Xiangyuan Zeng +1 位作者 Ziwen Li Yang Yu 《Astrodynamics》 EI CSCD 2024年第3期417-435,共19页
The tradeoff between accuracy and efficiency in gravitational field modeling for binary asteroid landing is one of the challenges in dynamical analyses.Four representative gravitational modeling methods are employed a... The tradeoff between accuracy and efficiency in gravitational field modeling for binary asteroid landing is one of the challenges in dynamical analyses.Four representative gravitational modeling methods are employed and compared in this study.These are the sphere-sphere model,ellipsoid-sphere model,inertia integral-polyhedron method,and finite element method.This study considers the differences between these four models,particularly their effects on the landing dynamics of a lander.A framework to simulate the coupled orbit-attitude motion of a lander in a binary system is first established.Numerical simulations are then performed on the natural landings on the second primary of the(66391)Moshup-Squannit system.The results show significant differences in the final landing dispersions,settling time,and sliding distance when applying the simplified models.On the basis of the modeling accuracy and computational efficiency,the finite element method should be chosen for future missions. 展开更多
关键词 landing dynamics contact dynamics gravitational field modeling binary asteroid
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Impacts of Transportation Arteries on Land Use Patterns in Urbanrural Fringe: A Comparative Gradient Analysis of Qixia District, Nanjing City, China 被引量:4
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作者 ZHANG Runsen PU Lijie ZHU Ming 《Chinese Geographical Science》 SCIE CSCD 2013年第3期378-388,共11页
Integrated transportation and land use studies are of major interest to planners because they consider the interaction between transportation development and land use change. Quantifying the impact of transport infras... Integrated transportation and land use studies are of major interest to planners because they consider the interaction between transportation development and land use change. Quantifying the impact of transport infrastructure on land use change is necessary for evaluating the role of transportation development in the process of land use and land cover change in the urban-rural fringe. Taking Qixia District of Nanjing City, Jiangsu Province, China as a typical urban-rural fringe area, this paper analyzes the patterns and charac- teristics of land use change along three major transportation arteries using land use data from 2000 and 2008. We examine the spatial differentiation and gradient of land use pattern around railway, expressway, and highway corridors to investigate whether land use change in the urban-rural fringe is related to distance from transportation arteries and to clarify the varying impacts of different forms of transport infrastructure on land use patterns. We find that construction land generally tends to be located close to major transportation arteries, and that railways have the most obvious influence on land use change in the urban-rural fringe, while the impact of expressways was not significant. We conclude that there exists a causal relationship between the presence of transportation arteries and land use change in the urban-rural fringe, but this relationship varies across different types of linear transnort infrastrncnlre. 展开更多
关键词 land use change transportation arteries gradient analysis land use dynamic degree urban-rural fringe
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Land use and landscape pattern change: a linkage to the construction of the Qinghai-Xizang Highway 被引量:9
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作者 YAN Jianzhong, ZHANG Yili, LIU Linshan, LIU Yanhua2, ZHENG Du (1. Inst. of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China 2. The Ministry of Science and Technology, Beijing 100101, China 3. College of Resources and Enviro 《Journal of Geographical Sciences》 SCIE CSCD 2002年第3期253-265,共13页
Based on digital land use data from 1995 to 2000 and road data, the land use and landscape changes of Golmud, Qumaleb and Zhidoi are studied on a macro-scale. Land use and landscape changes in highway buffer zones and... Based on digital land use data from 1995 to 2000 and road data, the land use and landscape changes of Golmud, Qumaleb and Zhidoi are studied on a macro-scale. Land use and landscape changes in highway buffer zones and city expansion are special subjects. A new formula is used to define the exact degree of dynamic land use. To adequately define land use and landscape pattern changes, the buffer zones, illustrating the changes at different distances from the road, are recognized with ArcGIS 8.1 software. Prominent changes took place in land use and landscape patterns from 1995 to 2000, and the area of built-up land increased by 323.8%. The comprehensive degree of dynamic land use is 2.25, and the degree of dynamic land use of built-up land is the highest, followed by cultivated land. Woodland has the lowest value. The used degree index of land resources declined by 38.8 from 1995 to 2000. Landscape changed dramatically which influenced ecological processes immensely. Different from the corridor effect of other traffic routes, the corridor effect of this section of road is not obvious and its “point” radiation effect can be easily seen. The expanding range of Golmud City is confined to a 3 km buffer, while for Wudaoliang, it is 1 km. No land use change happened in the Nanshankou buffer. 展开更多
关键词 land use change comprehensive index of the degree of land use diagnostic index of landscape degree of dynamic land use Qinghai-Xizang Highway
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ANALYSIS ON SPATIAL DIFFERENCE OF LAND USECHANGE BASED ON PHYSICAL AND CULTURALLANDSCAPE ATTRIBUTES──A Case Study at Mongolian AutonomousCounty of Qian Gorlos, Jilin Province 被引量:3
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作者 HUANG Fang, LIU Xiang-nan, XU Hong-mei, ZHANG Shu-wen, ZHANG Yang-zhen (Changchun Institute of Geography, the Chinese Academy of Sciences, Changchun 130021, P. R. China School of Urban and Environmental Science, Northeast Normal University, Changchun 13 《Chinese Geographical Science》 SCIE CSCD 2001年第1期50-56,共7页
Land use changes are regarded as landscape pattern change driven by many interactive natural and social-economic factors. Different combination of physical geographical elements induced the difference of spatio-tempor... Land use changes are regarded as landscape pattern change driven by many interactive natural and social-economic factors. Different combination of physical geographical elements induced the difference of spatio-temporal pattern of land use change. There are four physical geographical regions in Mongolian Autonomou County of Qian Gorlos of Jilin Province. Based on spatial analysis and statistical analysis, we conclude that the primary pattern of land use and the tendency of land use changes are all different in four physical geographical regions. During 1987 – 1996, the dominant land use change processes were from grassland or forest to arableland, from unused land to paddy and grassland to unused land. Though land use change is mainly affected by social and economic condition in short period, the composite characters of physical geographical elements controls land use dynamic process. The relationship between land use dynamic process and the character of physical geographical units differ in different regions. Possible human impacts on land use change are explored with application of buffer areas of series distance along main roads and radius around main settlements. A few models are built to describe the relationship between land use spatial change rates and distance to road and settlements. According to our result, the relationship with the proximity to roads was a negative liner function, with the change rate decreasing rapidly when moving away from roads. Within a distance of less 7.5km from main traffic lines, land use changes occur red more. The bulk of grassland was apt to be opened up for cultivation around the settlements and the transformation from dryland to paddy occurred within the distance of 1km away from settlements. 展开更多
关键词 land use change physical geographic region land use dynamic process effective coefficient cultural landscape variable
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Geospatial analysis of forest fragmentation in Uttara Kannada District, India 被引量:1
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作者 Ramachandra T V Bharath Setturu Subash Chandran 《Forest Ecosystems》 SCIE CSCD 2016年第3期206-220,共15页
Background: Landscapes consist of heterogeneous interacting dynamic elements with complex ecological, economic and cultural attributes. These complex interactions help in the sustenance of natural resources through b... Background: Landscapes consist of heterogeneous interacting dynamic elements with complex ecological, economic and cultural attributes. These complex interactions help in the sustenance of natural resources through bio-geochemical and hydrological cycling. The ecosystem functions are altered with changes in the landscape structure, Fragmentation of large contiguous forests to small and isolated forest patches either by natural phenomena or anthropogenic activities leads to drastic changes in forest patch sizes, shape, connectivity and internal heterogeneity, which restrict the movement leading to inbreeding among Meta populations with extirpation of species. Methods: Landscape dynamics are assessed through land use analysis by way of remote sensing data acquired at different time periods. Forest fragmentation is assessed at the pixel level through computation of two indicators, i.e., Pf (the ratio of pixels that are forested to the total non-water pixels in the window) and P~ (the proportion of all adjacent (cardinal directions only) pixel pairs that include at least one forest pixel, for which both pixels are forested). Results: Uttara Kannada District has the distinction of having the highest forest cover in Karnataka State, India. This region has been experiencing changes in its forest cover and consequent alterations in functional abilities of its ecosystem. Temporal land use analyses show the trend of deforestation, evident from the reduction of evergreen - semi evergreen forest cover from 57.31% (1979) to 32.08 % (2013) Forest fragmentation at the landscape level shows a decline of interior forests 64.42 % (1979) to 25.62 % (20] 3) and transition of non-forest categories such as crop land, plantations and built-up areas, amounting now to 47.29 %. PCA prioritized geophysical and socio variables responsible for changes in the landscape structure at local levels. Conclusion: Terrestrial forest ecosystems in Uttara Kannada District of Central Western Ghats have been experiencing threats due to deforestation with land use changes and fragmentation of contiguous forests, as is evident from the decline of interior forests and consequent increases in patch, transitional, edge and perforated forests. Interior or intact forest cover in this ecologically fragile region is now 25.62 %. Considering the accelerating rates of forest fragmentation in recent times, the focus should be on reforestation and regeneration of natural vegetation to sustain food and water security and the livelihood of local populations. This requires innovation with holistic approaches in the management of forests by involving all local stakeholders to minimize the encroachment of forests, and improvements in regeneration. 展开更多
关键词 Land use dynamics Forest fraqmentation Interior forests BIODIVERSITY Geophysical variables
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Land use/land cover change responses to ecological water conveyance in the lower reaches of Tarim River,China
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作者 WANG Shanshan ZHOU Kefa +2 位作者 ZUO Qiting WANG Jinlin WANG Wei 《Journal of Arid Land》 SCIE CSCD 2021年第12期1274-1286,共13页
The Tarim River is the longest inland river in China and is considered as an important river to protect the oasis economy and environment of the Tarim Basin.However,excessive exploitation and over-utilization of natur... The Tarim River is the longest inland river in China and is considered as an important river to protect the oasis economy and environment of the Tarim Basin.However,excessive exploitation and over-utilization of natural resources,particularly water resources,have triggered a series of ecological and environmental problems,such as the reduction in the volume of water in the main river,deterioration of water quality,drying up of downstream rivers,degradation of vegetation,and land desertification.In this study,the land use/land cover change(LUCC)responses to ecological water conveyance in the lower reaches of the Tarim River were investigated using ENVI(Environment for Visualizing Images)and GIS(Geographic Information System)data analysis software for the period of 1990-2018.Multi-temporal remote sensing images and ecological water conveyance data from 1990 to 2018 were used.The results indicate that LUCC covered an area of 2644.34 km^(2) during this period,accounting for 15.79%of the total study area.From 1990 to 2018,wetland,farmland,forestland,and artificial surfaces increased by 533.42 km^(2)(216.77%),446.68 km^(2)(123.66%),284.55 km^(2)(5.67%),and 57.51 km^(2)(217.96%),respectively,whereas areas covered by grassland and other land use/land cover types,such as Gobi,bare soil,and deserts,decreased by 103.34 km2(14.31%)and 1218.83 km2(11.75%),respectively.Vegetation area decreased first and then increased,with the order of 2010<2000<1990<2018.LUCC in the overflow and stagnant areas in the lower reaches of the Tarim River was mainly characterized by fragmentation,irregularity,and complexity.By analyzing the LUCC responses to 19 rounds of ecological water conveyance in the lower reaches of the Tarim River from 2000 to the end of 2018,we proposed guidelines for the rational development and utilization of water and soil resources and formulation of strategies for the sustainable development of the lower reaches of the Tarim River.This study provides scientific guidance for optimal scheduling of water resources in the region. 展开更多
关键词 land use/land cover change(LUCC) remote sensing land use dynamic index ecological water conveyance Tarim River
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HiLPD-GEE:high spatial resolution land productivity dynamicscal culation tool using Landsat and MODIS data
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作者 Tong Shen Xiaosong Li +4 位作者 Yang Chen Yuran Cui Qi Lu Xiaoxia Jia Jin Chen 《International Journal of Digital Earth》 SCIE EI 2023年第1期671-690,共20页
Land productivity is one of the sub-indicators for measuring SDG 15.3.1.Land Productivity Dynamics(LPD)is the most popular approach for reporting this indicator at the global scale.A major limitation of existing produ... Land productivity is one of the sub-indicators for measuring SDG 15.3.1.Land Productivity Dynamics(LPD)is the most popular approach for reporting this indicator at the global scale.A major limitation of existing products of LPD is the coarse spatial resolution caused by remote sensing data input,which cannot meet the requirement offine-scale land degradation assessment.To resolve this problem,this study developed a tool(HiLPD-GEE)to calculate 30 m LPD by fusing Landsat and MODIS data based on Google Earth Engine(GEE).The tool generates high-quality fused Normalized Difference Vegetation Index(NDVI)dataset for LPD calculation through gapfilling and Savitzky–Golayfiltering(GF-SG)and then uses the method recommended by the European Commission Joint Research Centre(JRC)to calculate LPD.The tool can calculate 30 m LPD in any spatial range within any time window after 2013,supporting global land degradation monitoring.To demonstrate the applicability of this tool,the LPD product was produced for African Great Green Wall(GGW)countries.The analysis proves that the 30 m LPD product generated by HiLPD-GEE could reflect the land productivity change effectively and reflect more spatial details.The results also provide an important insight for the GGW initiative. 展开更多
关键词 SDG 15.3.1 land productivity dynamics GF-SG Great Green Wall Google Earth Engine
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Integration of Remote Sensing and GIS in Studying Land Cover Trends and Conditions in the Middle Ziz Oasis,Morocco
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作者 Ali Essahlaoui Abba Mohamed +2 位作者 Eddahby Lhou Faouzi Mohamed Larabi Abdelkader 《International Journal of Geosciences》 2013年第7期1018-1023,共6页
A better understanding of the changing patterns of land use and vegetation cover is a major concern for countries whose ecosystems are under severe degradation. Indeed, the dynamics of land have direct implications on... A better understanding of the changing patterns of land use and vegetation cover is a major concern for countries whose ecosystems are under severe degradation. Indeed, the dynamics of land have direct implications on the availability of natural resources. The palm grove, of oases of Errachidia region, plays an important role in the environmental, social and economic of this region. This research was conducted in the Ziz middle, which is affected by changes in the conditions and composition of land cover change. The application of remote sensing, geographic information systems and satellite imagery analysis with multi-temporal and spatial land use provides, for territorial managers, data updated and improved and a synopsis for effective management of natural resources. This research explores the possibility of identifying, monitoring and mapping land use change and land use on the dynamics of the palm grove in the past 40 years. Satellite images used are Landsat images and multi-temporal dates (MSS (1972), TM (1987), ETM + (2001, 2006 and 2011). These images were georeferenced and radiometrically corrected. In our study, the use of vegetation indices NDVI, SAVI and MASAVI, highlight the magnitude of changes in vegetation cover between 1972 and 2011. A regressive pronounced canopy is generally recognized in the Middle Ziz. This decline is explained by the combined effect of anthropic action (urbanization) and climatic conditions. 展开更多
关键词 Morocco Remote Sensing GIS Ziz Watershed dynamic of Land Use NDVI
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Analysis of the dynamics of land use change and its prediction based on the integration of remotely sensed data and CA-Markov model,in the upstream Citarum Watershed,West Java,Indonesia 被引量:3
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作者 Fajar Yulianto Taufik Maulana Muhammad Rokhis Khomarudin 《International Journal of Digital Earth》 SCIE EI 2019年第10期1151-1176,共26页
In this research,the integration of remotely sensed data and Cellular Automata-Markov model(CA-Markov)have been used to analyze the dynamics of land use change and its prediction for the next year.Training phase for t... In this research,the integration of remotely sensed data and Cellular Automata-Markov model(CA-Markov)have been used to analyze the dynamics of land use change and its prediction for the next year.Training phase for the CA-Markov model has been created based on the input pair of land use,which is the result of land use mapping using Maximum Likelihood(ML)algorithm.Three-map comparison has been used to evaluate process accuracy assessment of the training phase for the CA-Markov model.Furthermore,the simulation phase for the CAMarkov model can be used to predict land use map for the next year.The analyze of the dynamics of land use change and its prediction during the period 1990 to 2050 can be obtained that the land serves as a water absorbent surfaces such as primary forest,secondary forest and the mixed garden area continued to decline.Meanwhile,on build land area that can lead to reduced surface water absorbing tends to increase from year to year.The results of this research can be used as input for the next research,which aims to determine the impact of land use changes in hydrological conditions against flooding in the research area. 展开更多
关键词 Multi-temporal remotely sensed data CA-Markov model dynamics land use change
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A Hazard Analysis-based Approach to Improve the Landing Safety of a BWB Remotely Piloted Vehicle 被引量:5
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作者 LU Yi ZHANG Shuguang LI Xueqing 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2012年第6期846-853,共8页
The BUAA-BWB remotely piloted vehicle (RPV) designed by our research team encountered an unexpected landing safety problem in flight tests. It has obviously affected further research project for blended-wing-body (... The BUAA-BWB remotely piloted vehicle (RPV) designed by our research team encountered an unexpected landing safety problem in flight tests. It has obviously affected further research project for blended-wing-body (BWB) aircraft configuration characteristics. Searching for a safety improvement is an urgent requirement in the development work of the RPV. In view of the vehicle characteristics, a new systemic method called system-theoretic process analysis (STPA) has been tentatively applied to the hazardous factor analysis of the RPV flight test. An uncontrolled system behavior "path sagging phenomenon" is identified by implementing a three degrees of freedom simulation based on wind tunnel test data and establishing landing safety system dynamics archetype. To obtain higher safety design effectiveness and considering safety design precedence, a longitudinal "belly-flap" control surface is innovatively introduced and designed to eliminate hazards in landing. Finally, flight tests show that the unsafe factor has been correctly identified and the landing safety has been efficiently improved. 展开更多
关键词 BWB RPV landing safety STPA system dynamics safety design precedence sagging phenomenon belly-flap
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Assessment of multifunctional landscapes dynamics in the mountainous basin of the Mo River (Togo, West Africa) 被引量:1
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作者 DIWEDIGA Badabate AGODZO Sampson +1 位作者 WALA Kperkouma LE Quang Bao 《Journal of Geographical Sciences》 SCIE CSCD 2017年第5期579-605,共27页
In this study, historical landscape dynamics were investigated to(i) map the land use/cover types for the years 1972, 1987, 2000 and 2014;(ii) determine the types and processes of landscape dynamics; and(iii) as... In this study, historical landscape dynamics were investigated to(i) map the land use/cover types for the years 1972, 1987, 2000 and 2014;(ii) determine the types and processes of landscape dynamics; and(iii) assess the landscape fragmentation and habitat loss over time. Supervised classification of multi-temporal Landsat images was used through a pixel-based approach. Post–classification methods included systematic and random change detection, trajectories analysis and landscape fragmentation assessment. The overall accuracies(and Kappa statistics) were of 68.86%(0.63), 91.32%(0.79), 90.66%(0.88) and 91.88%(0.89) for 1972, 1987, 2000 and 2014, respectively. The spatio-temporal analyses indicated that forests, woodlands and savannahs dominated the landscapes during the four dates, though constant areal decreases were observed. The most important dynamic process was the decline of woodlands with an average annual net loss rate of –2%. Meanwhile, the most important land transformation occurred during the transition 2000–2014, due to anthropogenic pressures. Though the most important loss of vegetation greenness occurred in the unprotected areas, the overall analyses of change indicated a declining trend of land cover quality and an increasing landscape fragmentation. Sustainable conservation strategies should be promoted while focusing restoration attention on degraded lands and fragmented ecosystems in order to support rural livelihood and biodiversity conservation. 展开更多
关键词 land cover dynamics spatio-temporal patterns swap change landscape fragmentation protected areas Mo River Basin TOGO
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