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41.
以烟台市为例,从生态环境协调性、经济可行性、社会可接受性等方面,构建了2004年城市土地可持续利用评价的指标体系,采用特尔斐等方法计算了其可持续利用度。结果表明,烟台城市土地利用目前仍处于可持续利用起步阶段。 相似文献
42.
Volkan Numan Bulut Mehmet Tufekci Celal Duran Mustafa Soylak Halit Kantekin 《洁净——土壤、空气、水》2010,38(7):678-683
A selective and sensitive method for the preconcentration, separation, and determination of palladium with flame atomic absorption spectrometry using 4,15‐bis[(4‐methylphenyl)sulfonyl]‐20,21‐dinitro‐2,3,4,5,6,7,9,10,12,13,14,15,16,17‐tetradecahydro‐8,11‐ethano‐1,18,4,8,11,15‐benzodioxa tetraaza cycloicosine (TNACIN) on XAD‐2010 was developed. TNACIN–Pd(II) complex formed acidic aqueous solution (0.075–0.100 M HNO3) was accumulated on XAD‐2010 and then eluted with 1 M HCl in acetone. The effects of some analytical parameters including pH, TNACIN amount, sample volume, eluent type, and concentration, sample flow rate and matrix ions were studied for optimization of the method. Detection limit and precision were calculated for Pd(II). This method was also verified with CRM and internal standard, and satisfactory results were obtained. 相似文献
43.
该文分析研究了彩山小流域的区域坡度和土壤特性,并根据区内土壤性质划分出4个小区域,即:自然坡度在20°~25°内为V1区,15°~20°内为V2区,10°~15°内为V3区,5°~10°内为V4区,分别反映了不同的土壤等级及土壤抗冲能力。同时,也研究出了一个系统化、理论化的科学依据i=V(10/3)/5B,并对所有砂石山区水土保持治理工作具有借鉴性和实用性。 相似文献
44.
国际减灾战略已从场地尺度工程性“硬”措施转向区域土地规划限制等“软”措施,即通过土地利用规划手段来限制土地开发行为,这是防范地质灾害最有效的手段。从土地利用规划和土地审批的法律地位、地质灾害填图与区划的公益性基础工作和实施地质灾害风险带土地开发限制管理等方面介绍了国际经验,并提出中国开展土地利用规划预防地质灾害的具体建议。 相似文献
45.
The environmental effects of disease are broadly recognized but still not fully understood. The impact of health on economic development has been well-documented, as have how changes in land cover can contribute to poor health. However, little is known about how changes in health may impact land use and land cover. Fallowing has long been regarded as an advanced, sustainable land use decision employed by subsistence agriculturalists. In the presence of a prolonged illness, however, subsistence agriculturalists may also potentially use fallowing as a coping mechanism. In this paper we seek to understand the extent to which fallowing is used as a coping strategy by households facing a prolonged illness. If illness threatens a household's labor supply, it could affect their ability to cultivate all of their land and may impact food security and general economic well-being. Additionally, it may also impact the actual landscape, as previously agricultural land may revert to a transitional state or land abandonment. This study employs mixed methods to determine if unhealthy agricultural households use fallowing as a coping strategy, identifies whether or not unhealthy fallowing households are more vulnerable agriculturally and economically than their healthier fallowing counterparts, and examines whether there is a land cover effect that can be detected using Landsat TM/ETM + satellite imagery. 相似文献
46.
Analyzing the tables and probability maps posted by Yan Y. Kagan and David D. Jackson in April 2002–September 2004 at http://scec.ess.ucla.edu/~ykagan/predictions_index.html and the catalog of earthquakes for the same period, the conclusion is drawn that the underlying method could be used for prediction of aftershocks, while it does not outscore random guessing when main shocks are considered. 相似文献
47.
基于遥感的呼伦贝尔盟农牧业土地利用变化及其对地区农业持续发展影响的研究 总被引:30,自引:1,他引:30
随着人口的增长, 人类活动对土地利用/土地覆盖变化的影响越来越大, “人口-资源-环境”问题越来越突出,因此,土地利用/土地覆盖变化的研究尤为重要。本文利用1986年和1996 年两期陆地卫星TM 数据, 分析探讨了呼伦贝尔盟近十年来农牧业土地利用数量变化及其区域差异,并通过计算耕地重心,分析了近十年来呼伦贝尔盟耕地的空间变化规律, 在此基础上进一步探讨了呼伦贝尔盟农牧业土地利用变化对地区农业持续发展的影响。结果表明: 十年来, 呼伦贝尔盟农牧业土地利用变化很大, 耕地面积大幅度增加,草地与未利用地面积减少;农牧业土地利用变化空间差异非常明显,导致十年来呼伦贝尔盟耕地重心向西北方向移动33.15 km , 耕地生态环境发生了显着变化; 呼伦贝尔盟耕地面积大幅度增加, 对合理开发利用耕地资源, 促进地区农业持续发展起到了积极的作用。 相似文献
48.
Geochemical patterns from two lag anomalies in the Cobar region of central New South Wales are described. The region is semi-arid, deeply weathered and some areas are covered by variable thicknesses of aeolian and alluvial transported overburden.Lag morphology and mineralogy are related to landform. In erosional landforms the surface is covered by lag, which is composed of coarse fragments derived locally from bedrock and displays varying degrees of ferruginization, together with a range of secondary pisoids. In depositional landforms the lag is less abundant and contains more pisoids. Deflation by sheetwash may lead to lag being partially buried by alluvium. In a large proportion of pisoid lag, hematite and goethite have been converted to maghemite, allowing ready separation into magnetic and non-magnetic fractions. The non-magnetic fraction is dominated by the lithic lag whereas the magnetic fraction is dominated by pisoid lag.The magnetic and non-magnetic components of the 2–11 mm lag fraction, milled to < 75 μm and subjected to HF-HNO3-HClO4 attack, give rise to distinct geochemical patterns at targets related to a variant of the Cobar style of Pb-Zn mineralization with variable silicification and to Zn mineralization in a swarm of quartz and carbonate veinlets. The patterns are influenced by metal source, lag type, surface chemical conditions and landtbrm. Differences in the correlation between metal contents in the magnetic and non-magnetic lag components, and between trace elements and Fe. indicate variable loss of Cu and Zn from the magnetic lag at some targets but retention of Pb. The presence of a readily cxtractable base metal component in the lag has implications for detecting anomalies in transported cover in the region. 相似文献
49.
为了更好地展示工业时代的空间组织模式,给出了一个包括时空背景、组织主体、组织客体、要素组成、要素状态、空间效率和技术7个部分的概念性框架;以该框架为基础,逐步分析了信息与通信技术对空间组织其他6个部分的具体作用;最后提出了一个判定空间组织效率的新视角。研究发现,信息与通信技术导致了传统空间组织模式的根本性重构,其对空间组织的影响是全方位的;在过去的30多年间,信息与通信技术对劳动生产率增长的贡献显著,这也证明了其作用下空间组织的高效率。 相似文献
50.
《The Geographical journal》2001,167(3):274-275
Helge Marcus Ingstad 1899–2001 By Kirsten A. Seaver
Francis William Carter 1938–2001 By David Turnock 相似文献
Francis William Carter 1938–2001 By David Turnock 相似文献