共查询到20条相似文献,搜索用时 15 毫秒
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M. M. Yoshino 《GeoJournal》1995,36(4):391-406
The International Geographical Union Reports
Land, sea and human effort 28th international geographical congress 相似文献3.
我国土地研究领域知名学者,原中国土地勘测规划院(现中国国土勘测规划院)院长、党委书记,曾担任中国土地学会副理事长的黄小虎研究员,应邀于2020年11月21日在清华大学土地利用与住房政策研究中心主办的“后疫情时代:国土空间规划与城乡高质量发展”论坛上作主题报告。他在发言中指出:传统规划体系存在多类型规划矛盾冲突的问题,多规合一为解决这一问题指明了方向、奠定了基础。十八大以后,中央对经济社会的发展战略、路线方针等陆续做出重大调整,国家发展内涵发生转变,要求突出发展质量,强调环境保护、农业农村优先。在体制机制上明确由新组建的自然资源部负责建立空间规划体系,其他部门不再编制涉及空间布局的规划,“多规合一”得到实现。国土空间规划的核心内容是国土利用和土地利用的功能分区,这也是用途管制的依据。 相似文献
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新时期市级国土空间总体规划具有开拓性和创新性,是我国国土空间规划体系的重要组成部分,既要起到承上启下的传导作用,又要解决前期各类空间规划体系、时限、标准、成果形式等矛盾,实现"一张图"。以福建省宁德市为例,基于新时期国土空间规划的新属性,明确了国土空间规划的基本内容,提出本轮宁德市国土空间总体规划中存在的主要问题为:土地资源紧缺,城镇拓展空间受限;城区量级较低,联动效应不强;综合配套不足,港口建设优势不明显;生态安全尚存风险,城市韧性有待加强。基于宁德市发展使命和目标,认为新时期宁德市国土空间总体规划的发展策略为:做好生态优先、绿色发展理念下的空间要素配置,完善以人民为中心的城乡人居环境规划,实施公共政策属性导向下的空间规划治理。建议市级国土空间规划,要以"三调"为抓手、以问题为导向、以底线为约束,立足全域,建立国土空间格局,探索构建形成一张层次传导、统筹、动态的"蓝图",有助于提升国土空间规划及空间治理能力。 相似文献
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Simultaneous changes in the representation of wetland and dry land taxa are a common feature of mid and late Holocene pollen diagrams from the coastal wetlands of North‐West Europe. Distinguishing both the areas affected and between natural and anthropogenic causes can be problematic. High temporal resolution, improved taxonomic procedures and multivariate statistics have been applied to two Thames estuary sites, along with simulation models, to resolve these issues. Large Poaceae pollen grains appear to be derived from wild grasses rather than cereals, while modelling indicates that even extensive clearance in dry land areas produces relatively minor changes in pollen assemblages where fen carr is the in situ vegetation. It is concluded that rapid/abrupt simultaneous pollen stratigraphic events in coastal wetlands are likely to have been caused by wetland vegetation changes alone. Simultaneous events, dating from c. 2150–1300 cal a BC, can be distinguished at 12 Thames estuary pollen sites. During this interval inter‐tidal environments expanded creating areas attractive to human populations for pasturage. This exploitation is likely to have led to further changes in wetland vegetation and increased clearance activity on adjacent dry land areas. In such circumstances disentangling the processes causing vegetation change is challenging, although considerably aided by the techniques adopted in this paper. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
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2002年塔里木河流域"四源一干"地表径流情势 总被引:4,自引:9,他引:4
2002年塔河流域内平原及山区气温都明显偏高, 平原降水偏多, 山区降水略偏多.3~10月 0 ℃层高度接近常年.塔里木河4条源流出山口天然径流量273.9×108m3, 比多年平均值227.0×108m3多46.9×108m3, 偏多20.7%, 属丰水年.其中发源于天山山脉的阿克苏河和开都河-孔雀河径流增幅大, 水量充沛, 属丰水年; 而发源于喀喇昆仑山脉的叶尔羌河和源于西昆仑山的和田河径流量保持多年均值年.4条源流入塔里木河水量为54.82×108m3.在塔里木河干流上游段耗水量25.42×108m3, 是干流最大的耗水区段, 中游段耗水量24.55×108m3, 下游段耗水量7.38×108m3.上、中游区间耗水量49.97×108m3, 占阿拉尔站年径流量的90.8%.从7月20日至11月10日共计114 d由博斯腾湖向塔里木河下游生态应急输水, 从博斯腾湖调水12.67×108m3, 恰拉水库分水闸向塔里木河输水2.339×108m3, 大西海子水库下泄3.313×108m3, 年内台特玛湖形成了28.74 km2的水域面积, 下游沿河地下水位普遍回升, 影响范围达800 km2, 生态效益十分显著. 相似文献
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A review is presented of the nature of tidal changes and their importance in the context of coastal hazards. This is done in order to illustrate the way in which tides do and may impact on the coast as a hazard and highlight the need for research to be carried out in this context. Three main aspects of tides are significant in this respect – these are: (1) tidal heights, including tidal range and the asymmetry or otherwise of the flood/ebb cycle; (2) tidal currents, the speed and direction of which affect sediment movement, sources and sinks; and (3) tidal mixing of fresh water with water of varying levels of salinity and differing temperatures. A variety of tools, from geological data to modelling, and tide gauges to satellites, may be used to assess tidal changes. Tides form the basis on which all other coastal processes operate and are therefore important with regard to the physical, chemical and biological hazards in the coastal zone. There is an urgent need to study tidal changes – both their nature and causes – in order to ensure successful coastal management. 相似文献
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The foraminifera and ostracods observed in a late Holocene sedimentary sequence within a fluvial valley at Boca do Rio in the coastal zone of the western Algarve, Portugal, reveal a general, though not smooth transition from marine to fluvial conditions. The relative influence of these two environments appears to depend on the degree of permeability of the barrier system at the coast. Optically stimulated luminescence dates and palaeoecological information obtained from the sequence suggest that barrier formation may be related to changes in climate and/or patterns of ocean current circulation. An unusual deposit rich in sand and gravel found within the otherwise mud-dominated sequence has been dated at AD 1801 ± 76 years. This deposit contains foraminifera and ostracods which indicate marine conditions, and which contrast markedly with the brackish-water, estuarine assemblages found in the mud deposits. The rapid transition in the foraminifera and ostracod assemblages indicates a short-lived coastal flooding, which may represent the tsunami associated with the Lisbon earthquake of AD 1755. The variations in the foraminifera and ostracod assemblages also suggest subsidence during the earthquake, with uplift having occurred in the period since then. 相似文献
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对水文科学的研究现状、主要进展和发展趋势进行了系统深入的总结和分析,其结果表明,社会需求是水文科学发展的根本动力,技术进步是水文科学发展的源泉。水文科学不仅要研究地表水文过程,还要研究各圈层界面上水分和能量交换过程,不仅要研究水在运动转化过程中的物理过程,还要研究水中各种化学成分的化学过程,特别需要加强水在水文循环和运动中生物过程的研究,从而使水文学向生态水文学的方向迈进。目前,生态水文学、全球气候变化影响是水文学研究的热点领域之一。今后除了进一步继续完善和深化水文科学的理论体系,还要不断丰富水文科学的社会服务功能,为经济建设和社会发展提供科技支撑。 相似文献
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根据气候条件的不同,沙漠可分为沙质荒漠和沙地两种类型.其中沙地地区降水相对丰富,具有降水、蒸发、下渗、产流及汇流等过程的相对完整的水文过程,但已有研究较少.以黄河中游沙地地区的秃尾河为例,分析了沙层水分分布及演化特性,进而将整个水文过程进行概化,得到物理意义明确,结构简单的概念性水文模型.该模型应用方便,精度较高.研究定量地阐明,研究区域沙层孔隙特征决定了沙层水分易保存而不易蒸发,使该地区径流深相对较大,而地下水丰富,调节能力强,是该地区河流径流年内分配均匀,年际变化小的重要原因.流域的非闭合性是该类地区水文研究中需要重点考虑的问题. 相似文献
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以珠江流域为研究对象,通过更新陆面水文模式所需的下垫面参数数据库,建立适合于珠江流域的大尺度陆面水文耦合模式系统,并利用该模式开展了1963~2006年流域水文水循环过程的数值模拟,通过与实测流量比较,系统考察了陆面水文耦合模型对珠江流域水循环各分量的模拟性能。分析结果表明,该陆面水文耦合模式对珠江流域年平均各水循环要素具有良好的模拟能力;模式对珠江流域干流主要控制水文站的月平均流量也有较高的模拟精度,模式模拟的水量平衡系数均接近1,相关系数均高于0.84,IOA相似度系数均高于0.9;相对而言,模式对流量峰值的模拟能力还有待提高。 相似文献
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【研究目的】近20年来,长江三角洲海岸带地区土地类型结构发生显著转化,海岸带开发与保护的矛盾凸显。本文旨在开展长江三角洲海岸带典型区土地利用变化与生态环境效应研究,为海岸带地区的土地资源可持续利用、海岸带环境保护提供科学依据。【研究方法】利用美国Landsat卫星系列遥感影像和中国资源卫星系列遥感影像,采用自动监督分类并结合目视解译,获取了研究区1995—2015年共5期土地利用分类数据,分析土地利用变化特征和趋势,探讨长江三角洲海岸带典型区城镇发展、围填海时空变化及生态环境效应。【研究结果】长江三角洲海岸带典型区(南通、上海、嘉兴、宁波和舟山)1995年至2015年,土地利用变化明显,耕地大幅度减少,比例从1995年的68.8%降为2015年的55.7%;城镇建设用地迅速扩张,年平均增加192.8 km2。【结论】在快速城市化过程中,人口、单位面积能源消耗等快速增加,环境问题凸显,大量的耕地转为建设用地,围填海使滨海湿地面积快速减小和消失,导致CO2和污染物释放与吸收严重失衡,海洋环境受流域和沿海城镇化建设的影响明显,长江口及邻近海域近20年来赤潮频发,研究区陆域和海洋环境压力增加。创新点:选取长江三角洲海岸带典型区,首次以1995—2015年5期序列遥感影像数据为基础,采用空间叠加分析方法,着重分析了建设用地和围填海区域的时空演化特征;以人类活动为主线,综合多种海洋环境指标,分析快速城市化进程中,建设用地和围填海导致的生态环境效应。 相似文献
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通过对青藏高原黄河源区鄂陵湖35cm长的沉积物岩芯(NR-1)中总有机碳含量(TOC)、总氮含量(TN)、碳氮比值(Corg/Ntot)以及有机碳同位素(δ13Corg)和总氮同位素(δ15Ntot)等地球化学指标的分析,并结合青海地区文献资料记载的人口数量变化以及高原湖泊水位记录,对研究区近1500a以来的气候环境变化进行了深入探讨。结果表明:近两百多年以来鄂陵湖沉积物中TOC和TN指标呈现明显上升的趋势,与青海东部地区人口数量变化趋势一致,表明近代人类活动已经对青藏高原最大淡水湖生态系统产生了显著的影响;而沉积物中δ13Corg值变化与青海湖水文环境重建指标具有可比性,说明高原大型淡水湖泊沉积物δ13Corg值可指示湖泊水位波动;此外δ15Ntot值变化趋势与青藏高原东北部已有的古温度记录总体一致,推测鄂陵湖沉积物δ15Ntot值可能响应了湖泊水体营养状态的变化,间接指示了湖泊夏季表层水温的波动。本研究为青藏高原腹地高海拔现代湖泊沉积物中有机碳和总氮含量及其同位素指标的解译提供了全新的思路。
相似文献16.
Junfang HUANG Ranghui WANG 《中国地球化学学报》2006,25(B08):163-164
The process of salinization has increased dramatically over the past several decades in the northwest arid zone of China. Soil salinization has been recognized as a major environmental problem for many years in the Tarim River Basin. It is the key issue of solving the soil salinization problem to study interaction between water and salt in arid zone, which will provide useful principle and methodology to its solution. Taking Tarim River and Bosten Lake for example, by systematically collecting the basic data of hydrogeology, meteorology, and social economy, we analyzed the interaction of water and salt of Tarim River and Bostan Lake in natural and artificial conditions in aspects of basins, oases, lakes and marshes. The results showed that: (1) Temperature and precipitation are both increasing gradually in the whole Tarim River Basin, the climate tends to be come warmer and wetter, but the water quality condition is not optimistic; (2) At the end of the 1950s, mineralization degree was less than 1.0 g/L from the upper reaches to the lower reaches of the Tarim River. At present, it is more than 3.0 g/L in Alaer Lake (the upper reaches of the Tarim River) except in July, August and October, during which it is less than 1.0 g/L. In Qiala (the lower reaches), it is more than 1.0 g/L except in March, moreover, it is about 5.0 g/L in July and December. The eco-water conveyance project implementation has still not improved Tarim River's water quality condition; (3) Bostan Lake was a tiny salt-water lake in the late 1950s, but the water-soil development of the oasis has aggravated the salinization in recent thirty years. Since the West Pumping Station was brought into operation in 1982, the Bostan Lake which accumulated salt has begun to be desalted. We consider that climate may not be the key factor for salinization in this area. Instead, socio-economic factors relevant to human activities should be mainly responsible for such changes, as is confirmed by our further analysis. In order to improve present situation of water-soil salinization, water resources utilization and management should be strengthened, highly efficient and water-saving irrigating technology should be spread, 相似文献
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Wilfred H Theakstone 《中国地质大学学报(英文版)》2010,(2)
The two ice caps of Svartisen,at the latitude of the Arctic Circle in Norway,supply 60 glaciers,ranging in size from >50 to <1 km2.Until the last two decades of the 19th century,the glaciers remained close to their maximum recent(Little Ice Age) size.In response to the prevailing 20th century climate,they have become smaller,but the changes have varied between glaciers.Climatic factors have not been the sole control of the variations.The response times of small,steep glaciers are shorter than those of the l... 相似文献
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Currently, one of the effective means in monitoring glacier change in regional scale is remote sensing and site-observation method. In this article, we present a study of comparing glacier area in 2005 derived from SPOT5 satellite image with area in 1972 derived from topographic maps. Moreover, Miaoergou (庙儿沟) flat-summit glacier is site observed to verify glacial change in regional scale. During the study period, glaciers located in the southern slope of Kalik (喀尔里克) Mountain re-duced their area by 12.3%. ... 相似文献
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渤海湾西部现代有孔虫群垂直分带的特征及其对全新世海面、地质环境变化的指示 总被引:1,自引:2,他引:1
对渤海湾西部潮间带和浅海区106个表层底质样品的活体与死有孔虫进行分析,筛选出8个优势种。利用死体有孔虫研究了优势种随水深(高程)变化的垂直分布特征,讨论了不同属种、不同有孔虫垂直组合带与地质环境、海面的定量关系。结果表明,有孔虫属种和组合的指示范围决定其作为地质环境及海面变化指标的灵敏性和精度。确立了研究区有孔虫海相性评价指数及与水深(高程)的相关性。根据对研究结果的实例应用的分析,恢复了研究区一个局部地点的相对海面变化曲线,为全新世地质环境和海面变化研究提供了一个新的尝试案例。 相似文献
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Adrian M Harvey Department of Geography University of Liverpool Liverpool L BX England 《中国地质大学学报(英文版)》2000,11(1)
INTRODUCTIONHow fluvial systems respond to environmental changedepends on how rapidly the effects of changes in sediment loadsupplied from upstream or changes in base level affectingdownstream zones are propagated through the system.Thisproperty has been defined as the coupling of the system(Harvey,2 0 0 0 a,1997a;Brunsden,1993;Brunsden andThornes,1979) .Coupling therefore relates to connectivity between thedifferent zones of the fluvial system,defined by Schumm(1977) as source areas,tra… 相似文献