共查询到20条相似文献，搜索用时 15 毫秒
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E. M. Yates 《GeoJournal》1992,26(3):265-275
In the first section concepts relating to the ownership of land, as voiced by various thinkers from Plato and Aristotle to Locke, Proudhon and Marx, are discussed. In the second section it is shown, that despite the high moral tone of the theorists, in practice land was acquired by theft, the theft perhaps followed by some retrospective attempts to achieve legality. Land was also expropriated on a large scale to be used as a counter in the struggle between the power groupa within the state. In the third section the present day relevance of estate ownership is briefly examined, with reference to political power and to environmental conservation. It is suggested that ideally there should be a return to a leasehold system, in Proudhon's terms possession rather than ownership, land leased from the community and forfeited if environmental damage is inflicted. There should be limit to the upward size of estates in order to limit the political advantages that accrue to families holding large areas of land. For these reforms to be effective and enormous enlargement of democratic processes is required, accompanied by a reduction in power of the central authorities, and by an increase in the financial and intellectual investment in education. 相似文献
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Quantitatively analyze the impact of land use/land cover change on annual runoff decrease 总被引：1，自引：0，他引：1
Annual runoff in Luanhe river basin was detected a downward trend and caused water crisis in Tianjin, China. To quantify the decreased runoff volume, Mann–Kendall test and Pettitt test were employed to check whether there existed significant trend and change points for annual rainfall and runoff time series in Panjiakou reservoir basin and 8 sub-watersheds. It was found that the annual runoff time series had a significant downward trend at 5 % confidence level, and the change point was at 1979 in Panjiakou reservoir watershed. Then double mass curve of annual rainfall and annual runoff was plotted, and two lines were fitted before and after 1979, respectively. Based on this method, the comprehensive effects of land use/land cover change on annual runoff were estimated. To further quantify the contributions of each main factor to annual runoff decrease, water stored in check dams and social water use in different periods were surveyed first. And then multi-linear regression was used to develop the relations between annual runoff and the driven factors. Water area decrease was identified to be the main factor contributing to annual runoff reduction. The results in this study can provide valuable information for water resources planners and policy makers. 相似文献
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利用能值分析方法揭示采煤沉陷区土地复垦行为特征,为采煤沉陷区土地复垦决策和土地利用导向提供科学依据。以徐州城北矿区复垦区为例,采用野外试验与能值理论分析相结合的方法,对采煤沉陷区土地复垦前后能值变化进行分析。结果表明:土地复垦是以人的价值行为为导向、自然资源为依托、生态系统流为骨架,来实现和提升采煤沉陷区生态经济系统功能;以恢复和提高区域生产力为价值导向的土地复垦行为可有效提高区域和产品服务功能,年净增加能值361.61×1016 sej;复垦后土地用途增加一定面积的鱼塘和储水区,在满足生产需求的同时,可提高区域水分涵养功能,年净增加能值4.6×1016 sej;土地复垦行为是通过调整采煤沉陷区土地利用结构、土地利用布局和土地利用行为,以实现生态经济系统能量流动与转换来增加区域生态经济系统能值。 相似文献
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阜新矿区地面塌陷灾害对土地生产力的影响 总被引：16，自引：0，他引：16
在研究地面塌陷对一个地区的影响时，一般只侧重于其对建筑物、铁路的影响，而对土地生产力影响的探讨和研究还不够深入。对于阜新矿区来说，地面塌陷对该区土地生产力的影响更是空白，前期的工作仅仅侧重于地面塌陷的调查，如果就地面塌陷对土地生产力的影响做一决的概括和分析，无疑会给今后治理由地面塌陷带来的灾害提供借鉴作用。本文结合大量实测、实算数据，应用土地复理论与方法对地面塌陷引起的土地侵蚀、土壤盐碱化、土壤湿度、土壤质量水平等四个方面做了较为系统的阐述，并对灾害的治理提出了见解。 相似文献
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The relationship between land surface temperature and land use/land cover in Guangzhou,China 总被引：1，自引：1，他引：0
The integration of remote sensing, geographic information system, landscape ecology and statistical analysis methods was applied
to study the urban thermal environment in Guangzhou. Normalized Difference Vegetation Index (NDVI), Normalized Difference
Build-up Index (NDBI), Normalized Difference Barren Index (NDBaI) and Modified Normalized Difference Water Index (MNDWI) were
used to analyze the relationships between land surface temperature (LST) and land use/land cover (LULC) qualitatively. The
result revealed that, most urban built-up lands were located in the middle part, and high LST areas mostly and were in the
middle and southern parts. Therefore, the urbanization and thermal environment in the middle and southern parts need to be
determined. Land surface temperature increased with the density of urban built-up and barren land, but decreased with vegetation
cover. The relationship between MNDWI and LST was found to be negative, which implied that pure water would decrease the surface
temperature and the polluted water would increase the surface temperature. A multiple regression between LST and each indices
as well as the elevation was created to elevate the urban thermal environment, which showed that NDVI, NDBI, NDBaI, MNDWI
were effective indicators for quantifying LULC impacts on LST. 相似文献
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Perera N. P. 《GeoJournal》1981,2(2):95-103
Mining of copper and other metals to a lesser extent is the mainstay of the Zambian economy. Copper is mined in the Copperbelt situated in the northern part of the country. It is not only the the most thickly populated part of the country but also the most urbanized. Urban centers developed with the mines as their nuclei and hence pose spatial problems between the needs of a rapidly increasing population on the one hand and the requirements of the mining industry on the other. The provision of raw material for the extractive industries is a geological one. Economic history shows the realization of these potentials and thirdly, lack of planning has permitted exploitation of minerals and dumping of wastes without much regard to reclamation. Spoilation of land by mining activity is mainly caused by the methods of mining as well as by the dumping of the solid and liquid wastes from the ore crushers and concentrators; while air pollution from sulphurdioxide and dust is from the smelters. Legislation has recently being enacted to regulate the dumping of wastes and for the reclamation of waste dumps. However, this has had only a minimal effect on the problem as yet. The soil from a dump which is ready for reclamation is analysed and methods of revegetating such a dump based on ecological principles is attempted. Finally, the conflict for land between the needs of a growing urban population and the requirements of the mining industry is discussed taking Kitwe, the capital of the Copperbelt as an example. 相似文献
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Assessing land use and land cover change in the Wassa West District of Ghana using remote sensing 总被引：1，自引：0，他引：1
John Manyimadin Kusimi 《GeoJournal》2008,71(4):249-259
Vast tracts of forests are lost globally every year especially in the developing countries of the tropics due to various human
activities such as lumbering, farming, bush fires, surface mining and urbanization. The rainforest in Ghana has experienced
rapid depletion since the 1980s. The impact of deforestation is widespread, affecting the livelihoods of local people and
disrupting the tropical ecosystem. There is a serious concern in the study area about climatic change, soil erosion, siltation
of rivers and loss in biodiversity which have an adverse impact on traditional medicinal plants of the local people. The study
examined the extent of land cover change through image differencing of Landsat TM 1986 and 2002. The image classification
indicated that, vegetative cover from 1986 to 2002 has been reducing whiles land use activities have been increasing. Closed
canopy, open canopy and plantation have significantly diminished and land use activities especially built ups, farms, mining
and openfields are more than doubled. The driving forces for the change in land cover are population growth, lumbering, socio-economic
and cultural practices of the people. Lumbering and mining have been some of the major causes of the changing landscape in
primary forest. Also the reliance on wood for domestic energy and the need to increase food productivity to feed growing population
have also contributed greatly to the rapid depletion of the vegetative cover. 相似文献
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Andrija Bognar Ph.D. 《GeoJournal》1996,38(4):407-416
As both Middle-European and Mediterranean country, the Republic of Croatia is composed of several regional units. Every single natural and geographical unit is not specific only in terms of its general natural features, but also by its role in linking Croatia with the rest of the world. Additional peculiarity of these geographic units is their complementary value, which gives good prerequisites for successful economic development of the country.In Pannonian section of Croatia prevail natural features close to those in other Central-European countries. Namely, this section of Croatia participates in Danube catchment area, linking Croatia with the rest of Central Europe. Dinaric Alps are typical mountainous area; in north-western part of the range (i.e. in the region of Gorski Kotar) they are very narrow, making thus possible a comparatively easy communication between Pannonian part of Croatia and the Adriatic coast. Coastal region of Croatia — stretching along the most of (north)eastern coast of the Adriatic — is predominantly characterised by Mediterranean natural features. Due to its size and share in total area of the country, territorial waters of the Adriatic sea can be accepted as the fourth natural and geographic unit of Croatia. 相似文献
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阜阳市地面沉降趋势预测 总被引：2，自引：0，他引：2
阜阳市地面沉降是典型的因抽汲松散岩层地下水引起水位(压)下降而造成的地面沉降。本文采用固结理论、回归分析、灰色理论等三种方法建立地面沉降预测模型,旨在探讨在未建基岩标、分层标的城市如何定量研究地面沉降,同时对该市地面沉降的发展趋势进行预测,提出控制地面沉降的措施。 相似文献
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本文依据对地裂缝的监测资料并结合地震及地面沉降等多方面研究成果,提出了西安地裂缝发展具有三个活动周期:Ⅰ级活动周期400～700年,Ⅱ级活动周期20～22年,Ⅲ级活动周期为一年,当前正值地裂缝活动高潮期。文中又据地裂缝的垂直活动速率及其对建筑物的破坏程度对地裂缝活动强度进行了分级,并提出减轻地裂缝危害的防治对策,这对西安市的城市建设和规划将具有一定的参考价值。 相似文献
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Yehua Wei 《GeoJournal》1993,30(4):435-440
Astract Recent economic reforms and shifts in land use planning in China have greatly changed the size and structure of urban land use. In this paper, an overview of the problems in urban land use and the impacts of economic reforms and planning policies on rapid urban land expansion and structural transformation is outlined. This is followed by statistical analyses to reveal determinants of urban land size. The study shows that urban land use in China has been improved, and urban land use size is related to urban reforms, urban land use adjustment, as well as to population growth and economic development. 相似文献
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Vaibhav Garg S. P. Aggarwal Prasun K. Gupta Bhaskar R. Nikam Praveen K. Thakur S. K. Srivastav A. Senthil Kumar 《Environmental Earth Sciences》2017,76(18):635
The sustainability of water resources mainly depends on planning and management of land use; a small change in it may affect water yield largely, as both are linked through relevant hydrological processes, explicitly. However, human activities, especially a significant increase in population, in-migration and accelerated socio-economic activities, are constantly modifying the land use and land cover (LULC) pattern. The impact of such changes in LULC on the hydrological regime of a basin is of widespread concern and a great challenge to the water resource engineers. While studying these impacts, the issue that prevails is the selection of a hydrological model that may be able to accommodate spatial and temporal dynamics of the basin with higher accuracy. Therefore, in the present study, the capabilities of variable infiltration capacity hydrological model to hydrologically simulate the basin under varying LULC scenarios have been investigated. For the present analysis, the Pennar River Basin, Andhra Pradesh, which falls under a water scarce region in India, has been chosen. The water balance components such as runoff potential, evapotranspiration (ET) and baseflow of Pennar Basin have been simulated under different LULC scenarios to study the impact of change on hydrological regime of a basin. Majorly, increase in built-up (13.94% approx.) and decrease in deciduous forest cover (2.44%) are the significant changes observed in the basin during the last three decades. It was found that the impact of LULC change on hydrology is balancing out at basin scale (considering the entire basin, while routing the runoff at the basin outlet). Therefore, an analysis on spatial variation in each of the water balance components considered in the study was done at grid scale. It was observed that the impact of LULC is considerable spatially at grid level, and the maximum increase of 265 mm (1985–2005) and the decrease of 48 mm (1985–1995) in runoff generation at grid were estimated. On the contrary, ET component showed the maximum increase of 400 and decrease of 570 mm under different LULC change scenario. Similarly, in the base flow parameter, an increase of 70 mm and the decrease of 100 mm were observed. It was noticed that the upper basin is showing an increasing trend in almost all hydrological components as compared to the lower basin. Based on this basin scale study, it was concluded that change in the land cover alters the hydrology; however, it needs to be studied at finer spatial scale rather than the entire basin as a whole. The information like the spatial variation in hydrological components may be very useful for local authority and decision-makers to plan mitigation strategies accordingly. 相似文献
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ABSTRACT: The colonization of the terrestrial environment by land plants transformed the planetary surface and its biota, and shifted the balance of Earth's biomass from the subsurface towards the surface. However there was a long delay between the formation of palaeosols (soils) on the land surface and the key stage of plant colonization. The record of palaeosols, and their colonization by fungi and lichens extends well back into the Precambrian. While these early soils provided a potential substrate, they were generally leached of nutrients as part of the weathering process. In contrast, volcanic ash falls provide a geochemically favourable substrate that is both nutrient-rich and has high water retention, making them good hosts to land plants. An anomalously extensive system of volcanic arcs generated unprecedented volumes of lava and volcanic ash (tuff) during the Ordovician. The earliest, mid-Ordovician, records of plant spores coincide with these widespread volcanic deposits, suggesting the possibility of a genetic relationship. The ash constituted a global environment of nutrient-laden, water-saturated soil that could be exploited to maximum advantage by the evolving anchoring systems of land plants. The rapid and pervasive inoculation of modern volcanic ash by plant spores, and symbiotic nitrogen-fixing fungi, suggests that the Ordovician ash must have received a substantial load of the earliest spores and their chemistry favoured plant development. In particular, high phosphorus levels in ash were favourable to plant growth. This may have allowed photosynthesizers to diversify and enlarge, and transform the surface of the planet. 相似文献
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陆地蒸发量推求的新方法 总被引：1，自引：0，他引：1
本文针对无径流深观测资料地区的实际情况，考虑了水田、旱地、水面积和不透水层地面面积比重，建立了相关计算公式推求陆地蒸发量。并选择了几个有实测资料的大型水库或水文站，利用建立的公式推求多年平均陆地蒸发量，与实测成果进行对比，计算结果的误差最大值只有1．77％，具有相当高的精度，可满足实用要求。 相似文献
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This paper provides a prospective analysis of supply/demand conditions for agricultural land in Canada and the U.S.A. according to various growth scenarios and an assessment of the economic and environmental costs associated with expanding and intensifying the cropland base. Future cropland expansion is estimated on the basis of the interrelationship between growth in demand and the productivity of cereal output. The adequacy of the land resource base is assessed by comparing individual projections with expected reserves of cropland adjusted for non-agricultural demands for land. Within the context of these findings the paper proceeds with a general discussion of the man-made, resource and environmental constraints to expanding production and the resulting economic and environmental costs to society. 相似文献