山区生态县区域协调发展的机制构建--以粤北始兴县为例   总被引：1，自引：0，他引：1  

税伟  陈烈  唐常春 《山地学报》2006,24(1):70-78

区域协调机制在不同类型地域和一种类型地域的不同的发展阶段是不同的。始兴县作为一个典型的山区生态县,工业进入加速发展时期,在此经济发展阶段的区域协调问题主要表现在:与外部区域经济、社会发展差距拉大,工业化与流域生态环境保护的矛盾已开始凸现,县政府协调区域发展的财政能力较低,区域协调机制不健全等。由此对始兴县的区域协调机制进行建构:建立健全多层次的区域协调机构;加大纵向和横向政府财政转移支付的力度;加强与相邻相关地区的协调;实施区域空间管治协调,保护城乡生态环境;科学合理选择产业,大力发展循环经济;全县推行绿色GDP考核等。  相似文献   

粤西地区县域城镇化发展探讨——以广东省高州市为例   总被引：1，自引：0，他引：1  

张志斌  雷春芳 《山地学报》2006,24(6):709-715

受地理条件、经济基础等因素的制约,粤西地区面临着城镇化进程滞后、整体发展层次偏低等一系列问题。加速推进县域城镇化是加快粤西地区经济发展,缩小与发达地区差距的内在要求和必然选择。以高州市为例,全面总结了粤西地区县域城镇化发展的特点及存在的主要问题,并在系统分析其城镇化发展机制的基础上,提出通过完善城镇体系,加强产业集聚,提升建设品位,增强城镇自我发展能力等促进县域城镇化发展。  相似文献   

紫色丘陵区水土保持林低效化的土壤成因     

何毓蓉廖超林  张保华 《山地学报》2006,24(B10):11-15

四川盆地紫色丘陵区的水土保持林低效化问题已较严重。研究了其土壤方面的成因。通过对土壤构造、土壤肥力特性、土壤结构性评价等研究，指出该区人工林地的土壤构造发育不正常，土壤腐殖质胶体积累量低。土壤结构质量差等林地土壤退化是土壤水土保持功能降低的主要原因。根据研究的初步结果，提出了相应的对策建议。  相似文献   

Climate change in Mt. Qomolangma region since 1971     

YANG Xuchao  ZHANG Yili  ZHANG Wei  YAN Yuping  WANG Zhaofeng  DING Mingjun  CHU Duo 《地理学报》2006,16(3):326-336

Using monthly average, maximum, minimum air temperature and monthly precipitation data from 5 weather stations in Mt. Qomolangma region in China from 1971 to 2004, climatic linear trend, moving average, low-pass filter and accumulated variance analysis methods, the spatial and temporal patterns of the climatic change in this region were analyzed. The main findings can be summarized as follows: (1) There is obvious ascending tendency for the interannual change of air temperature in Mt. Qomolangma region and the ascending tendency of Tingri, the highest station, is the most significant. The rate of increasing air temperature is 0.234 oC/decade in Mt. Qomolangma region, 0.302 oC/decade in Tingri. The air temperature increases more strongly in non-growing season. (2) Compared with China and the global average, the warming of Mt. Qomolangma region occurred early. The linear rates of temperature increase in Mt. Qomolangma region exceed those for China and the global average in the same period. This is attributed to the sensitivity of mountainous regions to climate change. (3) The southern and northern parts of Mt. Qomolangma region are quite different in precipitation changes. Stations in the northern part show increasing trends but are not statistically significant. Nyalam in the southern part shows a decreasing trend and the sudden decreasing of precipitation occurred in the early 1990s. (4) Compared with the previous studies, we find that the warming of Mt. Qomolangma high-elevation region is most significant in China in the same period. The highest automatic meteorological comprehensive observation station in the world set up at the base camp of Mt. Qomolangma with a height of 5032 m a.s.l will play an important role in monitoring the global climate change.  相似文献   

Palaeovariations in the East-Asian Monsoon Regime Geochemically Recorded in Varved Sediments of Lake Sihailongwan (Northeast China, Jilin Province). Part 2: a 200-Year Record of Atmospheric Lead-210 Flux Variations and its Palaeoclimatic Implications     

Georg Schettler  Jens Mingram  Jörg F. W. Negendank  Liu Jiaqi 《Journal of Paleolimnology》2006,35(2):271-288

Palaeovariations of the atmospheric ²¹⁰Pb flux in Northeast China (Long Gang area, Jilin province), quantified by high resolution ²¹⁰Pb measurements on seasonally laminated sediments of Lake Sihailongwan are presented on decadal scale. The mean flux of unsupported ²¹⁰Pb between 1790 and 1970 for the centre of the lake basin is 517 Bq m⁻² yr⁻¹ with maximum deviations between −23% and +27% of this value. Flux rates above this average were found between 1783 and 1813, around 1836, and between 1860 and 1901. The mean ²¹⁰Pb^exc flux rates derived were clearly lower around 1821, 1908, 1930, and 1953. The ²¹⁰Pb^exc flux reached its minimum of 344 Bq m⁻² yr⁻¹ during the period 1977–1982. The atmospheric flux of unsupported ²¹⁰Pb is correlated with the precipitation frequency during the summer monsoon and shows coinciding variability with geochemical proxies that document the groundwater inflow into the lake. Al₂O₃-rich dust of remote provenance scavenged by wet-deposition in the rainy season is the major carrier of the atmospheric ²¹⁰Pb^exc flux.  相似文献   

Ground motion scaling in the Marmara region, Turkey   总被引：1，自引：0，他引：1  

A. Akinci  L. Malagnini  R. B. Herrmann  R. Gok  M. B. Sørensen 《Geophysical Journal International》2006,166(2):635-651

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Investigating the lowermost mantle using migrations of long-period S–ScS data     

K. Chambers  J. H. Woodhouse 《Geophysical Journal International》2006,166(2):667-678

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Palaeovariations in the East-Asian Monsoon Regime Geochemically Recorded in Varved Sediments of Lake Sihailongwan (Northeast China, Jilin Province). Part 1: Hydrological Conditions and Dust Flux   总被引：2，自引：0，他引：2  

Georg Schettler  Qiang Liu  Jens Mingram  Jörg F. W. Negendank 《Journal of Paleolimnology》2006,35(2):239-270

The varved sediments of the dimictic Lake Sihailongwan (Long Gang mountain area, Jilin Province, Northeast China) represent a palaeoclimatic archive which documents the local precipitation frequency during the summer monsoon, and variations in the aeolian flux of dust with their remote sources in the arid and semi-arid regions of inner Asia. Based on a detailed discussion of sediment genesis in Lake SHL, dust flux rates and palaeohydrological conditions were reconstructed on a decadal scale over the past 220 years. The aeolian influx by dry and wet deposition was quantified and characterised in its chemical composition. Photosynthetic production in the lake is positively correlated with the inflow of nutrient-rich groundwater. The groundwater discharge largely reflects the strength of the summer monsoon. Net accumulation rates for biogenic silica were determined for annually laminated sediments from the centre of the U-shaped lake basin based on sediment data. In a Si-balance model of the modern lake, the depositional flux of biogenic silica could be independently quantified on the base of hydrochemical monitoring data. Comparison of the both estimates allowed to asses the focussing of the particle flux in the lake. Though water retention in Lake SHL is rather high (ca. 30 years), changes in the hydrological conditions are sensitively recorded in the sediments because (i) nutrient-rich groundwater discharges into the productive zone of the lake, (ii) a substantial proportion of the total dissolved Si-inventory of the mixed lake (ca. 30%) is annually consumed by diatom growth, and (3) sediment accumulation is substantially focussed towards the flat bottom of the lake basin. The bulk siliciclastic sediment fraction (ca. 75 wt.%) largely originates from influx of dust of remote provenance. In sediment thin-sections, the dry-deposited dust fraction is microscopically identifiable as seasonal silt layer. Aeolian input by wet-deposition shows a distinctly higher variability than the influx of dust by dry-deposition. As diatom production, wet-deposition of dust is positively correlated with the rainfall during the summer monsoon. The inferred positive correlation between rainfall and dust flux during the summer monsoon implies that dust deposition is determined by the out-wash efficiency of mineral particles for a permanent high atmospheric dust concentration over Northeast China in the last 220 years.  相似文献   

Berriasian (Lower Cretaceous) brachiopods from the Crimea     

S. V. Lobatscheva  T. N. Smirnova 《Stratigraphy and Geological Correlation》2006,14(6):642-654

Four successive assemblages of Berriasian brachiopods distinguished for the first time in the Crimea are correlated with concurrent subdivisions of the ammonoid scale. Berriasian brachiopods are represented by 44 species of 27 genera and 14 families, which are most complete in terms of taxonomic composition as compared to other concurrent brachiopod faunas known elsewhere. The assemblages are dominated by local species. As is proved, the Berriasian brachiopods studied are appropriate for age determination, subdivision and correlation of their host deposits. Their geographic distribution that has been analyzed elucidates connections of the Berriasian sea basins within the Mediterranean paleozoogeographic region.  相似文献   

新疆库鲁克塔格地区二叠纪脉岩群岩石地球化学特征，Nd、Sr、Pb同位素组成与岩石成因   总被引：12，自引：22，他引：12       下载免费PDF全文

姜常义姜寒冰  叶书锋夏明哲 逯东霞 《地质学报》2005,79(6):823-833

库鲁克塔格地区二叠纪脉岩群非常发育,主要岩石类型是辉绿岩,并有少量的斜闪煌斑岩、斜长玢岩和花岗斑岩。花岗斑岩属高钾钙碱性系列,具有A型花岗岩的稀土元素和微量元素地球化学特征;斜长玢岩的地球化学特征与花岗斑岩相似,二者都亏损U、Nb、Ta。斜闪煌斑岩的岩石化学组成属过碱性系列,显著富集轻稀土元素和大离子亲石元素。辉绿岩的岩石化学组成以钙碱性系列为主,稀土元素总量变化较大,Cs、Rb、Ba、Th元素丰度变化大,普遍亏损U、Nb、Ta。研究证明,辉绿岩脉的这些地球化学特征都与同化混染作用有关,大离子亲石元素丰度的变化还与热液蚀变有关。辉绿岩具有富集型Nd、Sr同位素组成,且变化范围大,是岩浆源区同化混染作用的结果。它们的铅同位素组成属低U(Th)/Pb值的正常铅,主要受混染物控制,并不代表源区特征。库鲁克塔格地区岩石圈地幔Nd、Sr、Pb同位素比塔里木板块西缘岩石圈地幔的富集程度更高,且变化范围大,反映了这两个地区岩石圈地幔的演化历史存在明显差异。  相似文献