地坑院里的流年

为什么住在地下？南沟任氏先祖到达的张村塬是陕县众多塬区之一。作为黄土高原地区一种独特的地貌,塬的形成有赖于流水经年累月的冲刷,所以其地形都是四周陡峭,有如切削,而中间则是一个巨大的平台——其面积足以覆盖一两个乡镇。     

西晋以来彭原古城附近沟谷的演变与复原

根据历史文献和考古调查,确定出甘肃省庆阳市西峰区彭原乡的两座古城遗址分别是后汉富平县城(GC1)和唐宋彭原县城(GC2),唐宋彭原县是北魏永和元年(434年)以后从今庙头嘴村搬迁到南庄村。据此推断泾河四级支流、马莲河三级支流彭原沟(当地称湫沟)流域的现代侵蚀沟,是在此年以后开始发育的。利用黄土高原现代侵蚀沟地貌年龄计算公式,计算出彭原沟主干沟道现代侵蚀沟的地貌年龄为1669±819年,沟口附近的现代侵蚀沟发育于西晋成帝咸康五年(339年)前后,其主要分支沟谷现代侵蚀沟的地貌年龄介于900±442～1300±638年之间。沟头平均延伸速度为3.367m/a,沟谷平均下切速度为0.063m/a,平均加宽速度0.19m/a。公式计算结果与考古结果基本相符,研究结果具有较高的信度。依此结果,将彭原沟及其支流地貌复原至西晋时期。     

基于SBAS-InSAR技术的庆阳北石窟寺区域稳定性监测与分析

区域稳定性监测是石窟寺长期保护的一项重要措施。本研究以庆阳北石窟寺所在区域为对象,基于2019年的15景Sentinel-1A卫星雷达影像,采用小基线集合成孔径雷达干涉测量(SBAS-InSAR)技术对研究区稳定性进行监测,获取了研究区雷达视线向形变速率及时序形变,分析了研究区形变的空间、时间分布规律及其原因。监测结果表明:北石窟寺所赋存的覆钟山山体整体稳定,存在微小形变,不存在潜在滑坡变形特征;研究区主要形变区沿河分布,蒲、茹两河交汇处形变最为明显;研究区时序形变呈现随季节变化的规律性,造成其规律性的原因为随季节变化的土壤侵蚀和董志塬固沟保塬项目的实施。该研究证明了InSAR技术在文物遗址区域稳定性监测的可行性,以及其在具有长期性、可靠性的优势,为石窟寺遗址长期预防性保护提供了新的思路和方法。     

洛川 征程上的亮点

从山西出发,过黄河,一路风尘,来到了洛川的黄土塬上。第一次踏上这块土地,好奇与激情,让人急速地扫描着周边的一切。塬上的风光,独特而有魅力。沟沟壑壑的黄土地貌,不禁让人想起了当年毛泽东率领工农红军转战陕北,在这厚实、博大的黄土塬上,耕织着中国革命的未来。洛川,一方平实无华的土地,却在中国革命的大业中,留下了不可磨灭的光辉一笔。     

水土流失与文物保护

水土流失,是指受自然因素(如降雨、风力、土壤、坡度、植被、地质等)和人为因素(如战争破坏、砍伐森林、滥垦滥牧、修路开矿等),造成土壤侵蚀和地表迳流,致使水土资源流失的现象。水土流失,带来了植被破坏、土地沙化、耕地减少、肥力下降、土壤干旱、洪水下泄、江河泛滥,生态失调,环境恶化,严重地阻碍和破坏农业生产,威胁城镇、工矿、交通、名胜古迹、历史文物的安全,给人民生命财产和国民经济造成严重损失。以陕西为例,全省有水土流失面积13.7万平方公里,占全省总面积70％。水土流失是从土壤侵蚀开始的,依照侵蚀的动力可分为水力侵蚀、风力侵蚀、重力侵蚀、冻融侵蚀四种。这种侵蚀的后果,就文物保护而言,不仅破坏了文物存在的人文环境,而且使文物本身受到了直接的破坏。例如陕北土地沙化,使西夏国都统万城变成     

宁夏固原于家庄墓地发掘简报

于家庄墓地在宁夏固原县西北约15公里,隶属彭堡乡撒门村,南距战国秦长城约10公里。墓地东靠塬,塬上为固原至银川的公路由南向北通过,西临大营河和冬至河冲积成的平川。墓地分布在坪的西侧边缘与大营河之间的坡地上,距今大营河床约200米(图一)。由于长期雨水侵蚀和当地群众取土,该墓地形成了两条东西向沟壑断崖,将墓地分割成北、中、南三个区。近年来,当地群众在墓地中区的南、北两侧取土,时常挖出牛、羊、马的头骨和铜器。固原博物馆     

独辟蹊径的元代云南史地研究力作——读《〈马可波罗行纪〉云南史地丛考》

方国瑜先生是中国西南历史地理研究的开拓者。他和林超民教授合著的《〈马可波罗行纪〉云南史地丛考》独辟蹊径,以翔实的材料证明马可·波罗确实到过云南与东南亚,为马可·波罗到过中国的证据提供了有力的、必不可少的补充;在元初云南政区、元代云南交通等方面提出了独到的见解,推进了元代云南史地的研究;表现出了清晰的学术传承轨迹和亲密无间的师生情谊,勘称学林佳话。     

改革开放以来芜湖市城市空间扩展及驱动力分析

以landsat MSS/TM/ETM+遥感影像为数据源,借助Arc GIS平台,选取城市空间扩展速度、扩展强度、紧凑度、分形维数、重心坐标、扩展弹性系数等指标,运用空间形态分析、叠加分析、等扇分析等方法,分析了改革开放以来芜湖市城市空间扩展时空特征,结合统计数据探究了扩展驱动力。结果表明:1979-2012年间,芜湖市城市空间扩展速度与强度具有较大波动性;人口增长与城市空间扩展的关系渐趋合理;城市空间形态由紧凑型向分散型转变;城市空间沿长江及主要交通线非均衡拓展;城市重心东偏北移;经济、人口、交通建设等是芜湖市空间扩展的主要驱动力。     

山西永济普救寺塔

<正>普救寺，位于山西省永济市蒲州古城东3000米处的峨嵋塬头之上，创建年代不详。据《蒲州府志》及寺内石碑记载，普救寺于北朝晚期已有，隋唐时期曾予扩建、增修，唐名西永清院，宋至清历代屡有修葺，是元代杂剧《西厢记》故事的发源地。     

黄土高塬沟壑区小流域村镇体系空间分布特征及引导策略——以陕西省淳化县为例

结合黄土高塬沟壑区的自然地理特点,以陕西淳化县为例,分析黄土高塬沟壑区小流域村镇体系的空间分布特征,提出"两沟夹一塬"单元是黄土高塬沟壑区基本的自然与社会经济组织系统。提出应以城镇发展为核心,逐步形成适合于地域特征的"枝状"村镇体系空间结构体系;应对分散的村镇适当迁并,充分发挥城镇的集聚效益,逐步形成黄土高原沟壑区"大分散-小聚合"的村镇体系格局;应以生态环境建设为目的,加强轴线地带非城镇化地区的空间管制。     

Borders,planning and policy transfer: historical transformation of development discourses in the Finnish Torne Valley

European Union spatial policies have become a key institutional context in which to study policy transfer processes in European border areas. These policies are, however, only the most recent part of these transformation processes which raises a need for more historically sensitive approaches. An historical perspective is important, since border regions are historical processes with particular path-dependent development trajectories and power structures. This paper aims to contribute to the discussion concerning the transformation of European border regions by looking at the policy transfer of regional development discourses in the Finnish Torne Valley. The study material consists of strategic development documents produced by the Finnish border municipalities and the municipal-based co-operation organizations from the 1930s to 2013. The examination, based on critical discourse analysis, shows that the transformation process is driven by national trends and the dominant planning discourse. Nevertheless, the particular border setting and local discourse on ‘united Torne Valley’ have also intertwined with political and economic processes during different time periods.     

左江流域水土流失现状与治理措施

左江流域包括扶绥、崇左、宁明、龙州、凭祥、大新六县市,位于南宁地区的西南部。由于长期以来不合理的开发利用,致使水土流失现象十分严重,不但有面蚀、沟蚀,有些地方甚至发展成崩岗。该区域总面积15092.39Km²,水上流失面积525.81Km²,本文在分析水土流失现状及成因的基础上,提出相应的水土保持措施。     

Land Use and Soil Erosion in Prehistoric and Historical Greece

Abstract

Soil erosion resulting from human exploitation of the land has attracted much public and scientific interest. Being regarded mainly as a modern phenomenon, however, its prehistoric and historical extent remain largely unexplored. Here we summarize three regional studies of Holocene erosion and alluviation in Greece, together with information derived from the literature, and conclude that most recorded Holocene soil erosion events are spatially and temporally related to human interference in the landscape. Wherever adequate evidence exists, a major phase of soil erosion appears to follow by 500–1000 years the introduction of farming in Greece, its age depending on when agriculture was introduced and ranging from the later Neolithic to the late Early Bronze Age. Later Bronze Age and historical soil erosion events are more scattered in time and space, but especially the thousand years after the middle of the 1st millennium B.C. saw serious, intermittent soil erosion in many places. With the exception of the earliest Holocene erosion phase, the evidence is compatible with a model of control of the timing and intensity of landscape destabilization by local economic and political conditions. On the whole, however, periods of landscape stability have lasted much longer than the mostly brief episodes of soil erosion and stream aggradation.     

西海固地区的环境重建与可持续发展

西海固地区位于黄土高原西北边缘的生态脆弱带,人口超载,是全国最贫困的少数民族地区之一,水土流失等环境问题极其严重。陷入了贫困、人口和环境之间互为因果关系的"PPE怪圈",实现可持续发展必须从打破"PPE怪圈"的关键环节入手。建立在协调人地关系基础之上的全面综合的环境重建是打破怪圈,实现可持续发展的基础,也是今后一段时期内可持续发展战略重点之一,环境重建是一项综合性系统工程、应与经济发展、社会进步相结合,并融入西部大开发之中。     

降雨对榆阳区明长城单体建筑破坏模式的试验研究

前期调查分析可知,降雨对榆阳区明长城单体建筑的破坏形式包括水力侵蚀和重力侵蚀两大类,主要影响因素为降雨特征、遗址保存形态和遗址土的性质。为了进一步了解降雨对该类土遗址的破坏方式及主要影响因素作用特点,按照相似理论要求设计模型试验,研究了降雨对榆阳区明长城单体建筑的破坏模式。试验结果表明,降雨对遗址模型的破坏方式与前期调查分析结果基本一致,水力侵蚀方式有冲沟侵蚀、片流面蚀、流水淘蚀和流水冲蚀,重力侵蚀方式有坍塌和滑塌。一般A型暴雨条件下,各种水力侵蚀方式均有发生,重力侵蚀发生次数相对较少;B型暴雨条件下,主要发生片流面蚀,重力侵蚀破坏发生次数较多。通过模型试验得出的降雨对遗址模型的破坏方式及发生特点方面的结论,可以在一定程度上为降雨对该类遗址破坏的评估和防治提供参考。     

An assessment of blanket mire degradation and Peatland Gully development in the Cheviot Hills,Northumberland

This paper provides the first systematic assessment of blanket mire degradation in the east Cheviot Hills, Northumberland. The extent of erosion is mapped over a 32 km² area of peat. Erosion affects 37% of the blanket peat. Erosion forms consist of anastomosing (7%), linear (21%) and dendritic (9%) gully systems together with peat slides (<1%). Topography is the primary influence on gully system pattern. Spatial variations in gully form can be partly explained by position in the stream network (stream order) and local variations in the depth of peat. A sequential scheme of gully development is described. Gullies evolve initially through a phase of rapid downcutting to the peat base, followed by lateral erosion and gully widening becoming dominant through a process of roughly parallel wall retreat. As gully width increases re‐deposition of peat occurs and re‐vegetation occurs on the gully floor. Comparative photography reveals that gully patterns have been stable over the past 32 years and in some areas for over 70 years. It is possible that gully systems in places are in excess of 500 years old.     

A Comparison of Past and Present Episodes of Gully Erosion at Wangrah Creek,Southern Tablelands,New South Wales

Erosion gullies at Wangrah Creek expose walls of at least two previous episodes of gully erosion. Past gullies were of a similar size to those of today but were not as widespread across the region at any particular time. The causes of past and present erosion are examined by mapping points of gully initiation and comparing the geomorphic history with an independent palaeo-environmental history. Past gullies were the result of intrinsically unstable conditions, possibly caused by the expansion of swampy deposits increasing runoff. In contrast, the present gully erosion is the result of major environmental change caused by European settlement, which had a greater effect on gully erosion than any other environmental change over the last 10,000 years. At Wangrah Creek, sites of gully initiation indicate that the present erosion was caused by localised disturbances to the valley floor.     

鄂尔多斯高原自然背景和明清时期的土地利用

鄂尔多斯高原位于我国北方沙漠-黄土边界带的关键位置上,通过百年来沙漠-黄土边界带概念的形成考察,从学术史上获得该论题蕴含有过渡带、敏感带、生态交错带内涵,这是众多学科研究意义所在。明代为防御元蒙势力,沿长城地带实行军屯,清代限于人口压力和财政因素,从长城内到长城外,将"变刍牧而桑麻"的活动扩展到大半个高原。汲取学术界已有成果,尤其是以长城作为判断毛乌素沙地南移及其与明清垦殖活动关系的一种考察方式,在影响毛乌素沙地的走向和幅度上,认为自然因素更显重要。尽管人类利用土地的形式和规模在逐渐升级,但在明清时期的演变过程中,仍只是作为荒漠-草原彼此进退的一种参与力量。