Taking two f alse color composite Landsat 5 TM (Thematic Mapper) images of band 4,3,2 taken in 1995 and 2000 as data resources, this paper carried out study on LUCC of Zhan gye oasis in recent five years by interpreta...Taking two f alse color composite Landsat 5 TM (Thematic Mapper) images of band 4,3,2 taken in 1995 and 2000 as data resources, this paper carried out study on LUCC of Zhan gye oasis in recent five years by interpretation according to land reso urces classification system of 1:100,000 Resources and Environmental Data base of the Chinese Academy of Sciences. The results show that great changes have taken place in landuse/landcover in Zhangye oasis since 1 995: (1) Changes of landuse structure show that cropland and land for urban c onstruction and built-up area increased, on the contrary, water area an d grassland decreased. These changes reflect the deterioration of eco-e nvironment and the acceleration of urbanization, and also indicate the problems existing in the arrangement of water and land resources betw een the upper and lower reaches of the Heihe River. (2) Regional diff erences of landuse/landcover are evident, characterized by following asp ects: in Sunan County located in Qilian Mountain area, unused land an d grassland decreased, but cropland and land for urban construction an d built-up area increased. In Minle and Shandan counties located in f oothills, unused land, water area and cropland decreased, but grassland and land for urban construction and built-up area increased. In Zhan gye City, Linze County and Gaotai County located in plain area of th e middle reaches of the Heihe River, unused land, water area and gra ssland decreased, while woodland, cropland and land for urban construction and built-up area increased.展开更多
Landuse/Landcover(LULC)changes are recognised as some of the major causes of environmental problems like land degradation and climate change.To achieve sustainability,we need to properly understand such changes in ord...Landuse/Landcover(LULC)changes are recognised as some of the major causes of environmental problems like land degradation and climate change.To achieve sustainability,we need to properly understand such changes in order to have adequate information that will enable us to design and implementing measures to mitigate their negative impacts.Doing this particularly requires a proper understanding of how stakeholders perceive the changes in general and their drivers in particular.Unfortunately,not much is known for many areas about the perspective of landuse stakeholders on drivers of LULC changes.This paper reports the results of a study conducted to examine the perceptions of different landuse stakeholders on drivers of LULC changes in Abuja Federal Capital Territory,Nigeria.Questionnaire survey was utilised,involving 514 households across four settlements,2 rural(Karshi and Orozo)and 2 urban(Nyanya and Karu)towns in the territory,which were complimented with Focus Group Discussions were conducted.The results obtained showed that urban dwellers are largely aware of drivers of changes in socio-economic drivers(physical development on lands,more commercial complex development and more institutional development).Rural dwellers are largely aware of environmental drivers of LULC changes(bush burning,livestock overgrazing,collections of wood and medicinal plants,and agricultural expansion).It was concluded that there is the need to bring about a harmonisation of the perceptions of LULC change drivers by the rural and urban dwellers so as to bring about a common front understanding and responding to LULC changes in the study area.展开更多
The projected 300% growth rate in the population of Enugu area and its environs by the year 2020 and the expected increase in waste generation necessitated the need to map out areas for waste disposal for future utili...The projected 300% growth rate in the population of Enugu area and its environs by the year 2020 and the expected increase in waste generation necessitated the need to map out areas for waste disposal for future utilization and as a protective strategy for the environment in Enugu area. Land capability index mapping using Geographic Information System (GIS) is one of the appropriate tools required for solving this problem. A total of 12 landuse determinants were selected as thematic data layers, and as basic factors influencing the choice of waste disposal landuse option in the area. The themes (thematic maps) generated from field/laboratory measurements and from literature, include slope, water table, surface and subsurface water conditions, elevation, geology, soil, drainage and geo-structural stability (fault, erosion, landslide and flooding) maps. The maps were scanned, digitized, georeferenced, and polygonized using autocard drawing capabilities to convert them into vector format and later exported to arc view software for analysis. The final processing using overlay model builder yields layers that display areas of preferred waste disposal sites in a map form, which generally shows areas of varying suitability (suitable, moderately (low) suitable and unsuitable). The waste disposal map of Enugu area shows that blocks1 (Obeagu area) and 3 (Ebe/Nsude areas) represent suitable and unsuitable areas, respectively, while block 2 (Ngwo area) has low suitability for waste disposal.展开更多
Watershed characteristics and land use/land cover study is necessary, for improved decision-making and for the resource management strategies. The methodology necessitates the provision of the base map from SOI toposh...Watershed characteristics and land use/land cover study is necessary, for improved decision-making and for the resource management strategies. The methodology necessitates the provision of the base map from SOI toposheet, delineation of drainage, preparation of slope and flow direction map using ASTER data and for the land use/land cover change detection, visual interpretation has been carried out using IRSP6-LISS-III data of 2005 and 2015. The land use/land cover analysis discloses several categories of land cover as well as land use present in Govindsagar variation from 2005 to 2015. The study area is mainly cramped to cultivated land and uncultivated land which show changes since last decade, there is an increase in cultivated land of about 4.86% of the geographical area where as uncultivated land (fallow land) shows a decline of 1.61% of the total geographical area, morphometric analysis reveals that area has impermeable subsurface materials and mountainous relief with dendritic drainage pattern with low surface runoff.展开更多
In 1965, the first forest map of Lebanon was produced. It is the oldest spatial distribution representation of junipers. Landcover maps of 2002 and 2010 are the most detailed spatial distribution that spatially shows ...In 1965, the first forest map of Lebanon was produced. It is the oldest spatial distribution representation of junipers. Landcover maps of 2002 and 2010 are the most detailed spatial distribution that spatially shows forests. Juniper forests are found in Lebanon as mainly as clear to low density coverage. High-density juniper forests are rarely found and only on Mount-Lebanon. Juniper forests are also mixed with oaks on the Eastern flank of Mount-Lebanon. Mapping juniper forests have demonstrated high degree of complexity, especially because of their low density and being mixed. The spatial representation of juniper forests was compared between the 1965 forest map and the landcover maps of 2002 and 2010. GIS environment was used to extract juniper forests from all maps. The degree of matching between juniper forests was investigated regarding the total area and spatial overlapping. Juniper forests were examined to their spatial locations, comparing the three maps. Spatial changes and anthropogenic effect were obtained, using Google Earth facilities. Google earth had satellite images acquired since 2014. Landcover maps of 2002 and 2010 have spatially matched forest map of 1965 by about 90% and 50% respectively. Spatial coverage of juniper forests were about 12,000, 26,000 and 28,000 ha on the 1965 forest map, landcover maps of 2003 and 2010 respectively. Anti-Lebanon juniper forests were not well represented on both landcover maps. Anthropogenic activities were mainly agriculture that affected juniper forests. Cultivations have replaced about 2% of the spatial coverage of 1965 Juniper forests. Quarries and urban existed inside juniper forests but in very limited areas. Juniper forests delineation did not completely match neither between the available maps, nor to the ground. Some juniper forests were not spatially represented on all maps or existing maps represented only portion of juniper forests. Juniper forest mapping requires more consideration and field investigation. High spatial resolution satellite images are among the solutions but delimiting juniper would require extensive fieldwork and specific remote sensing treatments. Being centuries old forests and characterized by High Mountain elevations, these important conifer forests are needed to be mapped with higher accuracy for better statistics and conservation.展开更多
Remotely sensed images have become a powerful source for landuse mapping.So far,no quantitative comparison and evaluation exist on the differences between an image-derived landuse map and a traditional landuse map.The...Remotely sensed images have become a powerful source for landuse mapping.So far,no quantitative comparison and evaluation exist on the differences between an image-derived landuse map and a traditional landuse map.The comparison and evaluation may indicate the possibility for the replacement of a traditional landuse map by an image-derived map.Map complexity is widely used to describe cartographic representations and map effectiveness from intellectual aspect and graphical aspect.This paper quantifies intellectual and graphical map complexities to explore the differences between these two kinds of maps.Intellectual complexity concerns the meaning or significations contained on a map.Graphical complexity concerns spatial characteristics of the graphical content on a map.Results show that the high graphical complexity of the image-derived landuse map is not harmonized with its low intellectual complexity.The intention of this paper is to encourage realistic cognition of the accuracy and problems existing in image-derived landuse maps.展开更多
基金National Natural Science Foundation of China for Young Scholars, No. 40101002 No. 40201001
文摘Taking two f alse color composite Landsat 5 TM (Thematic Mapper) images of band 4,3,2 taken in 1995 and 2000 as data resources, this paper carried out study on LUCC of Zhan gye oasis in recent five years by interpretation according to land reso urces classification system of 1:100,000 Resources and Environmental Data base of the Chinese Academy of Sciences. The results show that great changes have taken place in landuse/landcover in Zhangye oasis since 1 995: (1) Changes of landuse structure show that cropland and land for urban c onstruction and built-up area increased, on the contrary, water area an d grassland decreased. These changes reflect the deterioration of eco-e nvironment and the acceleration of urbanization, and also indicate the problems existing in the arrangement of water and land resources betw een the upper and lower reaches of the Heihe River. (2) Regional diff erences of landuse/landcover are evident, characterized by following asp ects: in Sunan County located in Qilian Mountain area, unused land an d grassland decreased, but cropland and land for urban construction an d built-up area increased. In Minle and Shandan counties located in f oothills, unused land, water area and cropland decreased, but grassland and land for urban construction and built-up area increased. In Zhan gye City, Linze County and Gaotai County located in plain area of th e middle reaches of the Heihe River, unused land, water area and gra ssland decreased, while woodland, cropland and land for urban construction and built-up area increased.
文摘Landuse/Landcover(LULC)changes are recognised as some of the major causes of environmental problems like land degradation and climate change.To achieve sustainability,we need to properly understand such changes in order to have adequate information that will enable us to design and implementing measures to mitigate their negative impacts.Doing this particularly requires a proper understanding of how stakeholders perceive the changes in general and their drivers in particular.Unfortunately,not much is known for many areas about the perspective of landuse stakeholders on drivers of LULC changes.This paper reports the results of a study conducted to examine the perceptions of different landuse stakeholders on drivers of LULC changes in Abuja Federal Capital Territory,Nigeria.Questionnaire survey was utilised,involving 514 households across four settlements,2 rural(Karshi and Orozo)and 2 urban(Nyanya and Karu)towns in the territory,which were complimented with Focus Group Discussions were conducted.The results obtained showed that urban dwellers are largely aware of drivers of changes in socio-economic drivers(physical development on lands,more commercial complex development and more institutional development).Rural dwellers are largely aware of environmental drivers of LULC changes(bush burning,livestock overgrazing,collections of wood and medicinal plants,and agricultural expansion).It was concluded that there is the need to bring about a harmonisation of the perceptions of LULC change drivers by the rural and urban dwellers so as to bring about a common front understanding and responding to LULC changes in the study area.
文摘The projected 300% growth rate in the population of Enugu area and its environs by the year 2020 and the expected increase in waste generation necessitated the need to map out areas for waste disposal for future utilization and as a protective strategy for the environment in Enugu area. Land capability index mapping using Geographic Information System (GIS) is one of the appropriate tools required for solving this problem. A total of 12 landuse determinants were selected as thematic data layers, and as basic factors influencing the choice of waste disposal landuse option in the area. The themes (thematic maps) generated from field/laboratory measurements and from literature, include slope, water table, surface and subsurface water conditions, elevation, geology, soil, drainage and geo-structural stability (fault, erosion, landslide and flooding) maps. The maps were scanned, digitized, georeferenced, and polygonized using autocard drawing capabilities to convert them into vector format and later exported to arc view software for analysis. The final processing using overlay model builder yields layers that display areas of preferred waste disposal sites in a map form, which generally shows areas of varying suitability (suitable, moderately (low) suitable and unsuitable). The waste disposal map of Enugu area shows that blocks1 (Obeagu area) and 3 (Ebe/Nsude areas) represent suitable and unsuitable areas, respectively, while block 2 (Ngwo area) has low suitability for waste disposal.
文摘Watershed characteristics and land use/land cover study is necessary, for improved decision-making and for the resource management strategies. The methodology necessitates the provision of the base map from SOI toposheet, delineation of drainage, preparation of slope and flow direction map using ASTER data and for the land use/land cover change detection, visual interpretation has been carried out using IRSP6-LISS-III data of 2005 and 2015. The land use/land cover analysis discloses several categories of land cover as well as land use present in Govindsagar variation from 2005 to 2015. The study area is mainly cramped to cultivated land and uncultivated land which show changes since last decade, there is an increase in cultivated land of about 4.86% of the geographical area where as uncultivated land (fallow land) shows a decline of 1.61% of the total geographical area, morphometric analysis reveals that area has impermeable subsurface materials and mountainous relief with dendritic drainage pattern with low surface runoff.
文摘In 1965, the first forest map of Lebanon was produced. It is the oldest spatial distribution representation of junipers. Landcover maps of 2002 and 2010 are the most detailed spatial distribution that spatially shows forests. Juniper forests are found in Lebanon as mainly as clear to low density coverage. High-density juniper forests are rarely found and only on Mount-Lebanon. Juniper forests are also mixed with oaks on the Eastern flank of Mount-Lebanon. Mapping juniper forests have demonstrated high degree of complexity, especially because of their low density and being mixed. The spatial representation of juniper forests was compared between the 1965 forest map and the landcover maps of 2002 and 2010. GIS environment was used to extract juniper forests from all maps. The degree of matching between juniper forests was investigated regarding the total area and spatial overlapping. Juniper forests were examined to their spatial locations, comparing the three maps. Spatial changes and anthropogenic effect were obtained, using Google Earth facilities. Google earth had satellite images acquired since 2014. Landcover maps of 2002 and 2010 have spatially matched forest map of 1965 by about 90% and 50% respectively. Spatial coverage of juniper forests were about 12,000, 26,000 and 28,000 ha on the 1965 forest map, landcover maps of 2003 and 2010 respectively. Anti-Lebanon juniper forests were not well represented on both landcover maps. Anthropogenic activities were mainly agriculture that affected juniper forests. Cultivations have replaced about 2% of the spatial coverage of 1965 Juniper forests. Quarries and urban existed inside juniper forests but in very limited areas. Juniper forests delineation did not completely match neither between the available maps, nor to the ground. Some juniper forests were not spatially represented on all maps or existing maps represented only portion of juniper forests. Juniper forest mapping requires more consideration and field investigation. High spatial resolution satellite images are among the solutions but delimiting juniper would require extensive fieldwork and specific remote sensing treatments. Being centuries old forests and characterized by High Mountain elevations, these important conifer forests are needed to be mapped with higher accuracy for better statistics and conservation.
基金supported by the National Key Basic Research and Development Program of China("973"Project)(Grant No.2006CB701306)the Program for New Century Excellent Talents in University(Grant No.NCET-06-0619)the Project of National Natural Science Foundation of China(Grant No.4097119)
文摘Remotely sensed images have become a powerful source for landuse mapping.So far,no quantitative comparison and evaluation exist on the differences between an image-derived landuse map and a traditional landuse map.The comparison and evaluation may indicate the possibility for the replacement of a traditional landuse map by an image-derived map.Map complexity is widely used to describe cartographic representations and map effectiveness from intellectual aspect and graphical aspect.This paper quantifies intellectual and graphical map complexities to explore the differences between these two kinds of maps.Intellectual complexity concerns the meaning or significations contained on a map.Graphical complexity concerns spatial characteristics of the graphical content on a map.Results show that the high graphical complexity of the image-derived landuse map is not harmonized with its low intellectual complexity.The intention of this paper is to encourage realistic cognition of the accuracy and problems existing in image-derived landuse maps.
