共查询到20条相似文献，搜索用时 265 毫秒
1.
为探讨黄土高原地区的生态恢复,以半干旱黄土丘陵区安家沟小流域的气象、土壤水分、地形图和土地利用图(1982年和2002年)为源信息,分析了不同植被类型的蒸散量和生态用水量、流域生态用水量及其与气候和土地利用变化的关系。研究结果表明:(1)流域土地利用结构从1982-2002年间变化较大,农地(特别是梯田)增加较快,乔木林地急剧减少,主要表现为毁林、开荒和造田;(2)研究区内各种植被/土地利用类型的蒸散量和生态用水都极大地受控于气候(特别是降雨量)的影响,其年际差异较大;(3)不同植被/土地利用类型间的蒸散量和生态用水差异明显,在各个年份乔灌林的生态用水量均大于农作物和自然草地的蒸散量和生态用水量,但生态用水的差异程度小于蒸散量的差异程度;(4)以自然草地(即荒草地)为标准,农作物的蒸散量和自然草地接近,但乔灌林地的蒸散量和生态用水量均远高于自然草地,难于实现土壤水分平衡;(5)流域土地利用结构的变化(主要是强耗水植被的减少)减小了流域生态用水量,增强了流域的水分平衡能力。 相似文献
2.
采用主成分分析法并结合SPSS,对1999-2013年重庆市土地持续利用与生态环境的耦合关系进行分析,研究结果表明:1999-2013年土地持续利用指数逐年递增,土地开发利用强度逐年不断加大,城镇化大规模的建设是土地利用强度升高的主要原因;生态环境质量除了在2000-2004年生态环境指数呈“V”字型发展之外,总体呈上升态势发展;重庆市土地持续利用与生态环境耦合发展度由0.387 4（轻度失调衰退土地利用损益型）上升至0.754 0（中级协调发展经济主导型）,但2011年情况有所变化,土地持续利用指数首次低于生态环境指数,耦合发展基本类型由生态主导型转向经济主导型发展,经济发展方式由土地利用制约型演变为生态环境制约型,生态环境效益滞后于土地资源经济效益。土地资源总体利用水平提高和生态环境改善的双重作用是耦合关系由失调发展转化为协调发展的主要原因。现阶段应坚持土地资源集约利用与保护并举,优化经济结构与技术创新齐下,发展循环经济和清洁能源,维系相对稳定的生态环境运行机制,确保重庆市土地资源可持续利用。 相似文献
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4.
土地规划实施管理的研究是新一轮土地利用规划的亮点,该文通过对规划实施存在问题及实施难的原因分析,对比国内外的土地利用规划,借鉴国外土地利用规划实施管理的理论与实践,最后对我国土地利用规划实施保障措施提出对策建议。在土地利用规划实施管理保障框图的基础上,该文特别就借鉴外国土地规划的理论与实践、基层地方的作用、公众参与和经济措施4个方面提出相关建议。 相似文献
5.
区域土地利用变化驱动力研究前景展望 总被引：29，自引：0，他引：29
区域土地利用变化驱动力研究旨在从典型区域角度揭示土地利用变化背后的真正动因及其作用机理，进而动态模拟、预测区域土地利用变化过程。土地利用系统的自组织性及其内驱动因子作用的复杂性，决定了其研究必须与某一特定区域相联系，以便确定合适的可定量指标来体现外生驱动因子的驱动效果。系统地识别土地利用系统在不同控制状态下的驱动因子及其多种时空尺度效应，建立具有综合模拟的区域土地利用变化动态模型，能减少土地利用系统通常受临界值域和突变所左右的局面。区域土地利用变化驱动因子识别、区域土地利用变化驱动机制分析、区域土地利用变化驱动过程模拟等的研究现状表明，为更好地理解区域土地利用变化的机制和原因，测度现有及未来土地利用变化的速率、过程和地点，支持政府相关决策的制定与实施，促使区域土地利用变化向有利于人类的方向发展,区域土地利用变化驱动力分析应优先考虑以下研究领域：①驱动力因子识别及其作用效应的尺度依赖性；②驱动力因子的贡献量化及其在具体区域的非均一分布；③驱动力因子作用过程的自然反馈机制模型化。
[HT5H]关〓键〓词：[HT5K] 相似文献
6.
The aim of this study was to determine land use changes in Datong basin using multitemporal Landsat data for the period of
1977–2006. Four dates of Landsat images from 1977, 1990, 2000, and 2006 were selected to classify the study area. Based on
the supervised classification method of maximum likelihood algorithm, images were classified into six classes: water, urban,
forest, agriculture, wetland, and barren land. A multidate postclassification comparison change detection algorithm was used
to determine changes in land use in four intervals. It is found that (1) urban land area increased 213% due to urbanization
that resulted from rapid increase of urban population and high-speed economic development, (2) agriculture area increased
34.0% due to land reclamation that resulted from rapid increase of rural population and improvement of irrigation capacity,
(3) forest area decreased 20.9% due to deforestation for urban area and agricultural use, (4) barren land area decreased 78.2%
due to cultivation for agricultural use, and (5) water and wetland decreased 39.1 and 67.1%, respectively, due to exploitation
of surface water and decrease of recharge from groundwater to surface water that resulted from over exploitation of groundwater. 相似文献
7.
基于分形维数和信息熵的土地利用景观格局变化研究——以西安市为例 总被引：3，自引：0，他引：3
信息熵和分形理论为研究地理学中系统的有序性和复杂结构现象的不稳定性提供了一条新途径,为研究土地利用景观格局变化提供了新的思路。以信息熵和分形理论为指导,在遥感和GIS技术支持下,对西安市土地利用景观格局演变的分形特征和信息熵进行分析,结果表明:1999-2008年,西安市土地利用景观结构趋于简单化,景观类型在空间上的稳定性逐渐增大;土地利用景观结构信息熵总体上呈逐渐下降趋势,即土地利用有序度逐渐上升,而无序度逐渐降低。 相似文献
8.
Nitrate pollution of ground waters from shallow basaltic aquifers,Deccan Trap Hydrologic Province,India 总被引：2，自引：0，他引：2
Analyses of groundwater samples collected from several locations in a small watershed of the Deccan Trap Hydrologic Province, indicated anomalously higher values of nitrate than the background. However, the NO3 concentrations in water from dug wells under pastureland where the subsurface material consisted of stony waste were minimum. The maximum values were reported for water from dug wells where the principal land use was agricultural. Lowering of NO3 values under shallow water-table conditions suggests denitrification. Higher concentrations of nitrate determined for samples collected from the wells with a deeper water-table indicate that denitrification process is inactive. The high values of nitrate coinciding with agricultural land use indicate fertilizers as the main source of nitrate pollution of ground-water. Decrease in Cl/NO3 ratio for agricultural land use confirms this inference. 相似文献
9.
With the rise in the number of applications using geospatial data and the number of GIS applications, the number of people who come into contact with geospatial data is increasing, too. Despite many attempts to introduce standardized formats in this area, they are often ignored by software developers as well as the users themselves for various reasons. When creating or exporting geographical data, users choose the format with regard to the software they use, or for which the data are intended. Users then have to deal with conversion of data formats, and considering its use also the issue of their transformation to the appropriate spatial reference system. This work presents findings related to this issue, obtained from several years of operation of an online service for the conversion and transformation of geographical data which is heavily used by users from all over the world. It presents statistics of individual formats use and spatial reference systems of geospatial data use from the point of view of both input and output data. The results, besides other things, are shown in the form of a pie chart map in which various needs of users from a variety of countries can be seen. The results of this work can be used especially by developers of applications which use geospatial data; it will allow them to quickly understand current user needs. 相似文献
10.
土地资源具有稀缺性和不可再生性,土地供给日渐紧张,拓展土地利用空间、将土地利用由平面趋向立体化发展的趋势日渐成熟。青岛市崂山区将建设用地使用权分层出让,不但垂范了法规政策,对区域经济的发展也具有很大的现实意义。 相似文献
11.
Study on Ecological Environment and Sustainable Land Use Based on Satellite Remote Sensing 
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下载免费PDF全文 GIS and RS techniques have been applied to interpret satellite data in 1992, 2000 and 2010. Further, the ecological environment factors of these three periods and the data for various types of land use have been obtained. LUDI in the Amur River Basin from 1992 to 2010 has been quantitatively analyzed by using the land use dynamic (LUDI) model and of land use transfer matrix model. The results indicated that from 1992 to 2010 the LUDI of land desertification is greatest, and is the most dramatic change. The comprehensive land use dynamic in the study area is 15.25, hence the land type is characterized by rapid change. In addition the area of woodland and farmland continues to increase, which has been mainly transformed from the mixture of forestland and grassland, marsh and wetland, this is an outcome of the production of shelter-forest plantation in North China, Northeast China and Northwest China. In the ten years period of the study, the area of desertified land has increased, changing mainly from a mixture of woodland and grassland. This study can rovide data for eco-geological environment management. 相似文献
12.
Hubert Wiggering 《Environmental Earth Sciences》2014,71(12):5037-5044
It is crucial that today’s land uses are not decoupled even further from prevailing site conditions. Quite the contrary, the site-adequate use of natural resources ought to be mandatory. This is provided for to a certain extent by the concept of multifunctionality and the exploitation of locational geological potential. Nevertheless, an appropriate course of action has yet to be taken. This can be achieved by applying an appropriate geo-based land use concept. To this end, however, from the scientific perspective alone, there has to be a new level of quality in the interaction between the various specialist disciplines to resolve the nexus problem and to achieve systemic approaches. The gap between the knowledge available in geology and the aspired land use concepts appears to be particularly large. A land use concept that pursues a systemic approach and refers to an adequate extent to geological knowledge provides options for future site-adequate land use as the basis for respective decision-makers or decision-making processes, not any longer conducted by political constraints or economic incentives only. 相似文献
13.
根据2009年第二次全国土地利用现状调查数据,运用数学方法并结合GIS技术,从县级尺度对泉州市的土地利用结构及其区域差异与成因进行定量分析,提出土地利用和城乡建设的差别化政策建议。研究结果表明：定量分析方法能很好揭示区域土地利用结构的地域分异,全市比较明显地存在4种不同的土地利用结构模式;影响研究区土地利用结构县域差异的主要因素与土地利用结构指数之间存在明显关系。 相似文献
14.
中国东部是否存在第四纪冰川作用之争论,自从李四光１９３４年提出该学说以来已经持续达６５年之久,迄今尚未终结。本文认为冰川时间单位实际上只是一个地质时(ｇｅｏｃｈｒｏｎ)。由于冰川是缓慢前进和后退的,因而冰期和间冰期的时间值从北向南随地而异,其界线是穿时的。通常承认冰期是一个单位,但不是时间岩石单位。中国东部第四纪冰川学说存在不肯定性暴露了气候地层划分和冰川地层单位命名的脆弱性。作者建议使用术语“杂砾岩”来取代“冰碛层”一词。 相似文献
15.
The use of quantum mechanics methods within the formalism of density functional theory requires a method to represent the electron wave functions. We compare the use of strictly localized basis functions based on atomic orbitals with the use of plane waves for the study of mineral properties and behaviour. Strictly localized functions enable the computational resources to scale linearly with the size of the system, whereas plane-wave methods scale more as the cube power of the system size, and for this reason the use of localized functions will be preferred for studies of large sizes. We present test results obtained from studies of cation ordering in spinel, garnet and amphibole phases, the high-pressure displacive phase transition in cristobalite, and the intercalation of organic molecules into pyrophyllite. We conclude that the use of localized basis sets provides a useful route forward for quantum mechanical studies of large-scale mineral problems.Received: 5 July 2001 相似文献
16.
长江口环境用水量计算方法探讨 总被引：8，自引：0，他引：8
环境用水在水资源配置中不能忽视，但环境用水问题的研究在理论上和具体计算方法上，目前国内外尚未有系统的成果。以长江口为例，以维持长江口水盐平衡并兼顾水沙平衡为目标，分析了长江口所必需的环境用水量。 相似文献
17.
汾河上游土地利用变化及其水文响应研究 总被引：4，自引：1，他引：3
以河岔水文站以上的汾河流域为研究区,采用土地利用转移矩阵和SWAT模型模拟方法,就汾河上游土地利用变化对水文过程的影响进行研究. 流域从1995-2000年,以耕地向林地和草地转变为主;从2000-2010年,城市建设用地不断增加,主要是对耕地的占用. 结果显示,在相同气候背景、不同土地利用情景（1995、2000年2010年）下,流域1992-2000年多年平均产水量微弱增加（分别为85.69 mm、85.75 mm和85.82 mm）,主要因为耕地持续减少,草地和城市建设用地不断增加. 但是各年产水量的大小关系不完全一致,枯水年和平水年与丰水年存在差异,而土壤水分呈现一致的减少状况. 子流域水平上,降水条件同样影响水文过程对土地利用变化的响应程度. 以上结果表明,汾河流域在退耕还林还草政策等影响下,土地利用发生变化并且直接影响流域的水文过程,但是流域水文过程对土地利用变化的响应还受到降水的影响. 相似文献
18.
Katherine J. Knierim Anna M. Nottmeier Scott Worland Drew A. Westerman Brian R. Clark 《Hydrogeology Journal》2017,25(6):1779-1793
Hydrologic budgets to determine groundwater availability are important tools for water-resource managers. One challenging component for developing hydrologic budgets is quantifying water use through time because historical and site-specific water-use data can be sparse or poorly documented. This research developed a groundwater-use record for the Ozark Plateaus aquifer system (central USA) from 1900 to 2010 that related county-level aggregated water-use data to site-specific well locations and aquifer units. A simple population-based linear model, constrained to 0 million liters per day in 1900, provided the best means to extrapolate groundwater-withdrawal rates pre-1950s when there was a paucity of water-use data. To disaggregate county-level data to individual wells across a regional aquifer system, a programmatic hierarchical process was developed, based on the level of confidence that a well pumped groundwater for a specific use during a specific year. Statistical models tested on a subset of the best-available site-specific water-use data provided a mechanism to bracket historic groundwater use, such that groundwater-withdrawal rates ranged, on average, plus or minus 38% from modeled values. Groundwater withdrawn for public supply and domestic use accounted for between 48 and 74% of total groundwater use since 1901, highlighting that groundwater provides an important drinking-water resource. The compilation, analysis, and spatial and temporal extrapolation of water-use data remain a challenging task for water scientists, but is of paramount importance to better quantify groundwater use and availability. 相似文献
19.
Amartanshu Srivastava Suresh Pandian Elumalai Elluru Venkata Ramana Raju 《Arabian Journal of Geosciences》2018,11(6):120
The objective of the present study was to delineate temporal and spatial changes in the coal fire and land use/cover within Bastacolla area of Jharia coal field. Studying this variation helped to decipher interconnection among the dynamics of the coal fire and concomitant changes in land use/cover. The detection of coal fires during a span of 14 years along with transitioning land use/cover was cost-effective and enabled planning for management of coal resources and environment. Landsat series of satellite data of 2002, 2009, 2013, and 2016 were processed for generating land surface temperature profiles vis-a-vis classified land use/cover of the study area. A single cut-off temperature was derived for mapping of coal fires using land surface temperature profile from 2002 to 2016. The satellite images were classified using support vector machines, and for depicting land use/cover change, post-classification change detection was done. Classification accuracy obtained was excellent with kappa coefficient ranging from 0.897 for classified image of 2002 to 0.799 for classified image of 2016. Results revealed that coal fires had shifted to the central west part of the area. Furthermore, pockets of coal fire from northern and eastern part of the study area have diminished. OB dumps and coal quarry/coal dump may be attributed towards the spatial change in coal fire while; OB dumps showed connotation with the highest temperature zones. Ground verifications for temperature profiles and coal fires were carried out using thermal camera which enunciated good agreement with results. 相似文献
20.
邢台市水生态系统修复可行性研究 总被引：1，自引：1，他引：0
通过对邢台市水生态环境的演变、现状以及水资源开发利用中存在的问题的论述和分析,从水资源可持续利用的角度,对邢台市水资源利用现状,工农业及生活节水潜力、百泉岩溶水生态修复,平原及地下水修复等问题进行了深入的分析。最终阐明了实现邢台市水生态系统修复的可行性和长期性。 相似文献