基于国家级保护地空间分布特征的国家公园选址研究——以福建省为例

国家级保护地是我国国家公园建设的重要基础,对其进行空间分布特征解析,可以有效识别景观资源聚集的热点区域,为我国国家公园选址提供参考依据。借助ArcGIS和CrimeStat等空间分析工具,结合福建省自然地理空间和社会经济空间,对省内现有11类119处国家级保护地进行空间分布特征分析,结果表明:福建省国家级保护地对各类一级和二级自然地理和社会地理空间实现了全覆盖;保护地在各自然地理区划以及行政区划间的分布不均衡,总体呈凝聚型分布;集中在热量条件适中、相对湿度较高、水资源丰富及植被、土壤、地形地貌等景观类型多样的区域;区域生产总值和人口数量与保护地空间分布没有直接联系。根据区域内保护地的聚集情况,进行国家公园试点热点探测,筛选出8个具有代表性及现实推广意义的热点单元,为国家公园试点的空间选择提供参考。     

河流与城镇体系结构形成的关联特征及空间表现

基于相互作用视角分析了河流与城镇体系结构形成的关联特征及空间表现。河流作为重要自然要素,与城镇体系结构的形成演变存在紧密的关联性,并在空间上表现出不同的特征,研究结果表明:1从数量结构来看,城镇依河流呈非均衡集中分布格局;2规模结构方面,城镇对河流依赖随规模递增而增强,且大城市分布与河流等级、区位密切相关;3职能结构方面,沿河城镇职能具有河流属性特征,且区域中心城市或综合性城市多沿河分布;4空间结构方面,河流引导沿岸城镇空间布局分异,改变中心地空间布局理论结构,且引导沿岸城镇空间体系呈现出点—轴、双核等结构模式。     

河流景观生态学概念、理论基础与研究重点

较系统地概述了河流景观生态学概念、理论基础与研究重点及其在河流生态学研究中的应用。在河流景观视角下,将河流作为空间异质性的完整景观单元,而不仅仅是传统景观生态学研究中将河流作为采样点或线。河流景观生态学将景观生态学原理与方法应用于河流景观的空间分布、斑块、格局、时空尺度、异质性、干扰和联结性等研究之中,并作为其关键研究内容。此外,建议强化河流景观制图、河流生态系统健康评价与服务价值评估、河流生态系统修复以及河流景观管理等研究内容。总之,把河流生态系统视为"河流景观",将有助于从更加综合的视角和更普遍的概念框架开展河流乃至滨河湿地的研究与保护工作。     

基于自然区域特征和生态代表性的加拿大国家公园动态反馈遴选机制

国家公园遴选机制作为多种要素和多个环节有机结合的一套完整制度安排,核心是国家公园遴选标准和国家公园遴选流程。这是国家公园建设的基础,传递了国家公园建设的核心理念,也是中国国家公园体制建设需要优先解决的领域。国家公园遴选机制是加拿大国家公园建设的科学途径和政府治理的重要成果,具有较高的独特性和科学性,得到了世界自然保护联盟(IUCN)的高度认可和大力推崇。从系统论角度入手,综合运用文献、比较、叠图等方法分析加拿大国家公园遴选机制,结果表明:该机制基于自然区域特征建立国家公园体系,基于生态代表性选择国家公园单元,将遴选标准嵌入系统规划;遴选流程表现为联邦政府主导、上下参与,遴选进展通过土地利用状况变化动态表征;遴选标准、遴选流程和遴选进展共同构成一个动态反馈的遴选机制;该遴选机制有利于达成共识、形成合力、加快建设和扩展保护对象。针对保护地遴选机制中存在的问题,中国国家公园遴选机制应该:遴选标准"点面"结合,可以突破部门分治所造成的自然要素分割,实现不同类型保护地管理机构的整合;遴选流程"上下"互动,可以改变中央在遴选流程中处于被动地位的处境,更好地体现国家公园遴选的国家意志和科学性;遴选进展"动静"联系,可以动态反馈国家公园建设进展,同时反映相对恒定愿景和系统规划。     

温带海洋性气候的区域差异

温带海洋性气候大致位于南纬和北纬40°～60°之间的大陆西岸。这类气候分布于世界上四个区域：①西欧区。包括大不列颠群岛、法国、荷兰、比利时、丹麦、德国西部和斯堪的纳维亚半岛西部等地。②北美区。主要分布在北美洲西北部太平洋沿岸地区,包括阿拉斯加东南部、加拿大的不列颠哥伦比亚省、美国的俄勒冈和华盛顿两州部分地区。     

大别山东南缘河流裂点成因及其地貌演化意义

河流裂点形态特征蕴含了区域河流演化的历史信息，是认识区域地貌演化、构造运动、气候变化及人类活动潜在相互作用机制的切入点。以往裂点成因研究多选择在河流演化控制因素比较典型的地区，成因分析方法也相对单一。本文以河流演化环境复杂的大别山东南缘为研究区，基于标准陡峭指数、面积高程积分、坡度-面积双对数法和降水侵蚀力等探讨区域河流裂点形成原因。研究表明：(1)研究区5条河流干流纵剖面均处于不均衡状态，发育68个裂点。(2)研究区裂点发育受到构造活动、岩性、降水等多种因素影响。构造运动特别是郯庐断裂带等的断层活动是区域裂点发育的主导因素，共形成45个裂点，超过裂点总数量的65%。(3)研究区地貌演化受到构造运动影响，区域断层活动显著，并且构造运动活跃性存在差异，山地区域构造运动活跃性高于山前盆地，西南区域构造运动活跃性高于东北区域。本研究可为复杂区域河流演化研究提供借鉴，并从新的视角进一步了解大别山地区地貌演化过程。     

2000年以来中国对美国直接投资的时空演变

2000年以来,随着中国外向型经济的快速发展,以及中美经贸合作伙伴关系的不断深化,中国 对美国直接投资规模持续扩大,至2012年,美国已成为接收中国对外直接投资最大的国家。利用地理集中指数和空间自相关,以美国50个州和哥伦比亚特区为研究单元,分析2000-2014年中国对美国直接投资的时空演变过程及发展趋势。结果表明：①2000年以来COFDI在美国地域分布的不平衡程度有所下降,整体逐渐趋向均衡;②美国吸收COFDI的区域差异较大,南部地区总量领先但增速较慢,东北部、中西部、西部地区实力平均但增速较快,整体差距逐渐缩小;③在空间分布上,呈现由沿海向内陆,由南部向中西部扩散的趋势,表现为“以点带线,多点成面”的时空演化过程;④总体来看,COFDI的空间分布存在较弱的空间自相关性,集聚程度尚不显著,呈现“集聚--随机分布--离散”的空间形态,局部区域形成“冷、热区”的分化。     

长江中下游流域自然保护地空间分布及其与人类活动强度关系研究

以2015年土地利用类型数据为基础，计算长江中下游流域人类活动强度，采用最邻近指数、地理集中指数和不均衡指数分析研究区自然保护区、风景名胜区等六类国家级自然保护地分布特征，并定量揭示保护地空间分布与人类活动强度的关系，旨在为长江中下游流域建立基于人类活动强度的各类自然保护地管控策略提供科学依据。结果表明：1）人类活动高、较高、中、较低和低强度带在研究区的占比分别为3.74%、9.83%、14.98%、30.81%和40.63%；高等级强度带主要分布在长江三角洲平原、江汉平原等平原区，低等级强度带主要分布在秦岭山区、武陵山区等山地丘陵区。2）湿地公园、森林公园、风景名胜区和地质公园的空间分布类型为均匀型，水利风景区和自然保护区为凝聚型；六类保护地在各人类活动强度带空间分布不均衡。3）湿地公园、森林公园、水利风景区、自然保护区、风景名胜区和地质公园分别在中、较高、高、低、较低和低强度带密度最大；在高等级强度带“人地”矛盾更突出，应加强对自然保护地的保护力度和人类活动管控，尤其针对湿地公园、森林公园和水利风景区。     

城市化进程中平原河网地区河流结构特征及其分类方法探讨

平原河网地区河流结构发育受到自然条件和城市化的双重影响。依据遥感解译数据,围绕城市化水平、河流形态、河流结构和河流调蓄功能四个维度,就建成区面积比例、河流长宽分布、河系分维、河流调蓄能力等具体指标,分析了城市化水平和土地利用特征不同区域的河流空间形态、结构特征和功能状态,探讨了城市化进程中平原河网地区河流结构的可能演化轨迹,尝试建立了城市化影响下平原河网地区河流结构分类方法,提出了城市河流综合整治过程中应充分重视保护自然河流结构,注重发挥河流综合功能等观点。     

欠发达地区旅游经济差异的空间分析——以甘肃省为例

运用ESDA方法结合GIS 软件,以甘肃省14 个市州作为研究单元,选取人均旅游收入作为评价指标,利用空间分析方法对2003-2014 年甘肃省旅游经济的空间差异进行了分析。研究表明：2003-2014 年甘肃省旅游经济空间差异显著,旅游热点地区长期且稳定地分布在河西走廊一带,其他地市长期分布在旅游冷点地区;由于旅游资源丰度、旅游经济区位和地区经济发展水平等因素的影响,甘肃省旅游经济发展呈“伞”型结构。位于“伞”型主干的城市旅游经济发展水平高,而位于“伞”型两端的城市旅游经济发展较为缓慢。针对这种差异,提出：（1）应当不断梳理甘肃省旅游资源赋存,提升旅游资源内涵,变资源优势为产业优势、竞争优势,提高地区旅游业的整体竞争力。（2）实施非均衡的区域旅游协调发展战略。（3）不断挖掘区域旅游特色,推动旅游产业与文化产业的融合发展,提高旅游供给水平,增强区域旅游竞争力。     

Defining the Historical Northeastern Forested Boundary of the Great Plains Grasslands in the United States

The Great Plains is the grasslands of the central United States, but precise delineation of this region has evaded agreement due to the transition between Great Plains grasslands and forests of the eastern United States. After comparing Great Plains delineations in readily available geographic information system layers, I established a northeastern boundary using evidence from historical tree surveys during the 1800s. Additionally, I described tree presence within the Great Plains over time and potential drivers of change. The definition documented here diverges from others by including most of Iowa and part of Illinois, and even small sections in Indiana and Wisconsin, but excluding Missouri due to regular tree presence overall at landscape scales of ecological subsections. In this definition, the Great Plains had an extent of 2.29 million km² in fifteen states, including Indiana and Wisconsin, and 2.19 million km² after removal of open forests in Oklahoma and Texas. Tree presence occurs within the Great Plains and tree encroachment is not a new process; however, tree encroachment is increasing in the Great Plains, which causes a decrease in the grasslands region. Nevertheless, clarifying the historical eastern boundary provides a solution to the problem of competing versions of the Great Plains region. Key Words: ecotone, prairie, savanna, tree encroachment.     

Mineralogical maturity in dunefields of North America, Africa and Australia

Studies of dunefields in central and western North America show that mineralogical maturity can provide new insights into the origin and evolution of aeolian sand bodies. Many of the world's great sand seas in Africa, Asia and Australia are quartz-dominated and thus can be considered to be mineralogically mature. The Algodones (California) and Parker (Arizona) dunes in the southwestern United States are also mature, but have inherited a high degree of mineralogical maturity from quartz-rich sedimentary rocks drained by the Colorado River. In Libya, sediments of the Zallaf sand sea, which are almost pure quartz, may have originated in a similar fashion. The Fort Morgan (Colorado) and Casper (Wyoming) dunefields in the central Great Plains of North America, and the Namib sand sea of southern Africa have an intermediate degree of mineralogical maturity because their sources are large rivers that drained both unweathered plutonic and metamorphic rocks and mature sedimentary rocks. Mojave Desert dunefields in the southwestern United States are quite immature because they are in basins adjacent to plutonic rocks that were their sources. Other dunefields in the Great Plains of North America (those in Nebraska and Texas) are more mature than any possible source sediments and therefore reflect mineralogical evolution over time. Such changes in composition can occur because of either of two opposing long-term states of the dunefield. In one state, dunes are stable for long periods of time and chemical weathering depletes feldspars and other weatherable minerals in the sediment body. In the other state, which is most likely for the Great Plains, abrasion and ballistic impacts deplete the carbonate minerals and feldspars because the dunes are active for longer periods than they are stable.     

Changing Patterns of Population Density in the United States

Changing population density is often ignored in studies of population growth and population transfer in the United States. We show that there is a complex relationship between patterns of population growth and density increase by state. The largest gains in density are in the states of the northeastern megalopolis, California, and Florida. Analysis of the 150 counties with the greatest increases in density between 1980 and 1990 shows that they are well distributed across the United States including the larger metropolitan areas of the “Rustbelt.” In general, the most densely populated states and places are becoming more densely populated, a concept we refer to as densification.     

Changing Patterns of Population Density in the United States

Changing population density is often ignored in studies of population growth and population transfer in the United States. We show that there is a complex relationship between patterns of population growth and density increase by state. The largest gains in density are in the states of the northeastern megalopolis, California, and Florida. Analysis of the 150 counties with the greatest increases in density between 1980 and 1990 shows that they are well distributed across the United States including the larger metropolitan areas of the “Rustbelt.” In general, the most densely populated states and places are becoming more densely populated, a concept we refer to as densification.     

CONCENTRATIONS OF NONEMPLOYMENT INCOME IN THE UNITED STATES *

Nonemployment income from investments, pensions, welfare benefits, and so forth provides one third of total personal income in the United States. Spatial concentrations of this income occur in places such as Florida, Michigan, Arkansas and the Great Plains. These concentrations result largely from the presence of older persons who are the principal recipients of nonemployment income. In turn, spatial concentrations of older persons result from “aging in place,” which typifies the Great Plains, or from amenity-bound immigration by older persons, which characterizes Florida.     

REGIONAL-SCALE TROUGHING OVER THE SOUTHWESTERN UNITED STATES: TEMPORAL CLIMATOLOGY,TELECONNECTIONS, AND CLIMATIC IMPACT

Regional-scale middle- and upper-tropospheric troughing over the southwestern United States represents a departure from the modal circulation pattern for western North America. Once developed, southwestern troughs often are associated with positive vorticity advection aloft, surface cyclone formation, and moisture advection over areas of the western Great Plains and Intermountain West. These trough systems may play an important role in the precipitation climatology of the western and central United States. However, very little work has focused on the temporal climatology, developmental characteristics, or climatic impacts of southwestern troughs. This study provides a detailed climatology of southwestern troughing that focuses on: (1) the temporal frequency of these events; (2) the teleconnective circulation changes that are associated with their development; and (3) the importance of these systems in the precipitation climatology of the western and central United States.

The temporal climatology of southwestern troughs reveals that most of these systems occur during spring and autumn, with somewhat fewer events in winter and very few events in summer. An examination of 500-mb geopotential height and 24-hr height change composites during trough development shows that much of the wave-train activity that accompanies trough onset is limited to the North Pacific and North American regions. These changes are characterized by the amplification and eastward movement of a ridge/trough couplet over the eastern Pacific, which is preceded by synoptic-scale transient wave activity over the western and central Pacific. While southwestern troughs occur less than 30% of the time, southwestern trough-derived precipitation comprises over 60% of the monthly totals for some sites.     

HISPANIC MIGRATION AND POPULATION REDISTRIBUTION IN THE UNITED STATES*

The US Hispanic population has grown rapidly over the last two decades and remains geographically concentrated in nine states. Redistribution away from core states through internal migration has been largely offset by heavy immigration to traditional areas of Hispanic concentration. Geographical patterns of Hispanic miration show broad similarities to overall patterns of population redistribution in the United States. New York and California serve as key spatial redistributors or pivots in the Hispanic migration system.     

CIRCULATION PATTERNS AND TEMPERATURE FIELDS ASSOCIATED WITH EXTENSIVE SNOW COVER ON THE NORTH AMERICAN CONTINENT

Weekly snow cover areas, derived from the NOAA/NESS Northern Hemisphere Digitized Snow and Ice Cover Data Base, were correlated with weekly temperature anomalies across the United States and with weekly 700-mb geopotential heights over the North American sector. The correlations were computed for snow cover across the entire North American continent as well as the western and eastern United States for the winters 1966–67 through 1979–80. Extensive snow cover is associated with negative temperature anomalies across most of the continental United States. The strongest relationship occurs along the eastern flank of the Rocky Mountains from the Canadian border to the central Great Plains and reflects the southward movement of cold arctic air masses toward the Gulf of Mexico. An anomalous trough over the western part of North America is responsible for extensive snow cover in the winter. The surface storm track is displaced southward during winters with heavy snow cover, with cyclones occurring more frequently in the southern Plains and southeastern United States. Moist Gulf of Mexico air advected northward by the southerly flow aloft is an important prerequisite condition for the occurrence of extensive snow cover in the eastern United States during the first half of winter.     

Pn anisotropy studies in northern Britain and the eastern and western United States

Summary. Available seismic refraction data from three different continental areas, northern Britain and the eastern and western United States, has been studied for possible P_n , velocity anisotropy using the methods described by Bamford. There are various deficiencies in the time—distance data used in each case but, while the uppermost mantle beneath northern Britain and the eastern United States seems to be isotropic within the limits of measurement error, there is a small but significant anisotropy beneath the western United States.
Both the amount (up to 3 per cent) and the direction (70–80° east of north) of this anisotropy are very similar to the results obtained in the Pacific Ocean off California. We tentatively conclude that this anisotropy is present as a consequence of the subduction of oceanic lithosphere beneath the western United States.     

Inferring lake depth using diatom assemblages in the shallow,seasonally variable lakes of the Nebraska Sand Hills (USA): calibration,validation, and application of a 69-lake training set

The Nebraska Sand Hills are a distinctive eco-region in the semi-arid Great Plains of the western United States. The water table underlying the Sand Hills is part of the High Plains/Ogallala aquifer, an important water resource for the central Great Plains. Lake levels are affected directly by fluctuations in the water table, which is recharged primarily by local precipitation and responds quickly to climatically induced changes in regional water balance. Instrumental records are available for only 50–100 years, and paleolimnological data provide important insights into the extremes and variability in moisture balance over longer time scales. A set of 69 lakes from across Nebraska was used to establish a statistical relationship between diatom community composition and water depth. This relationship was then used to develop a diatom-based inference model for water depth using weighted averaging regression and calibration techniques. Development of the inference model was complicated by strong intra-seasonal variability in water depth and the linkages between depth and other limnologic characteristics, including alkalinity, water clarity and nutrient concentrations. Analysis of historical diatom communities from eight lakes allowed for the reconstruction of lake-level fluctuations over the past several thousand years. Comparisons of the more recent portion of these reconstructions with the instrumental Palmer Drought Severity Index (PDSI) showed that sediment records may not faithfully reflect short-term fluctuations in water level, except where sedimentation rates are very high. However, large and persistent changes in moisture availability were discernible even in longer, low-resolution records. Thus, diatoms are a useful addition to the tools available for understanding past drought in the central Great Plains, especially when trajectories of change are constrained by data from multiple sites or other proxies.