基于MAPGIS的投影变换在地质灾害调查与区划中的应用

本文介绍了“县（市）地质灾害调查与区划”项目通过MAPGIS中地图投影变换功能的应用,实现跨幅图件的拼接、经纬网线的自动生成,以及地质灾害点数据的投影转换,快速、准确地生成动态的地质灾害点分布特征图件,全面地分析研究该地区地质灾害的发生、发展及分布规律,从而为地质灾害防治和管理提供科学决策依据。     

大漠胡杨

<正>胡杨是古老、美丽而神奇的树种,能在极端干旱的地区成林,对旱区环境甚至当地社会稳定都具有重要的作用。很多人赞美胡杨,但人们对胡杨在干旱环境中的适应特征等仍然知之甚少。如今,环境变化和人为干扰正深刻地影响着这一珍稀树种的分布和生存。珍贵的胡杨胡杨(Populus euphratica)属于杨柳科胡杨亚属木本植物,又称异叶杨,是第三纪的孑遗植物,是最古老的杨树之一,为珍稀濒危树种。胡杨分布于全球20多个国家,但超过60%的胡杨林分布在我国,而我     

图件扫描数字化的误差分析

从图件扫描数字化误差理论分析出发,利用定向点和采样点的自动中中和多种人工采点方法的实验数据,对误差原因及分布规律进行了验证,得出了扫描数字化精度与手扶跟踪数字化精度相比具有一定的优势,对提高大比例尺图件数字化的精度和速度具有借鉴意义。     

塔克拉玛干别里库姆沙漠胡杨沙堆流场风洞模拟

利用全站仪及RTK对胡杨沙堆进行三维形态实测采样,以实测数据为基础,制作胡杨沙堆实验模型。在风洞中用3组不同风速(6、10、14m/s)对胡杨沙堆模型进行纯气流流场的模拟实验,结合研究区胡杨沙堆表层沉积物样品粒度分布特征,印证流场风洞模拟的准确度,并分别测定在5组不同风速(6、8、10、12、14m/s)下胡杨沙堆后100cm处的输沙率。结果表明:气流在胡杨沙堆迎风坡强度较大,沿着沙堆迎风坡加速爬升;至沙堆背风侧,气流强度明显减弱,一部分气流方向发生逆转形成强涡流区,最终在沙堆后方气流强度逐渐恢复;胡杨沙堆流场变化特征与沙堆表层沉积物平均粒径的分布特征相吻合;胡杨沙堆后方,输沙率随高度的增加呈指数函数迅速降低,风蚀输沙量为无植被时的78%,输沙量较平沙地明显减少。     

基于GIS的内蒙古道路密度空间分异特征研究

基于道路网络图件数据和相关统计数据,结合ArcGIS,GeoDa和SPSS软件,运用叠加分析、空间插值分析、趋势面分析及空间自相关分析等方法分析了内蒙古自治区道路密度空间格局特征.结果表明:内蒙古自治区道路密度呈现显著的空间自相关性,呼包鄂地区、赤通地区和呼伦贝尔市中部地区成为道路密度的热点集中区,其他地区是冷点集中区;道路密度呈现出东西两边低中部高,南高北低的趋势;且在空间分布上存在集聚特征.在研究结果的基础上,深入分析了内蒙古自治区道路密度空间格局特征形成机理,经济发展、人口和交通固定投资是影响内蒙古道路密度空间格局的重要因素.     

GeoMDIS在多目标区域地球化学调查中的应用

GeoMDIS区域地球化学空间数据管理与分析系统,在多目标区域地球化学调查中的应用体现在数据库的管理、图形数据与属性数据、数据处理与分析、专题图制作、空间分析等方面.根据调查数据分析处理和编绘地球化学图件,以待查明测区元素地球化学分布和分配特征,进行资源环境评价与基础地质研究,为国家及地方经济社会科学可持续发展和进行区域规划提供依据.     

靖边无定河流域首次发现天然胡杨林

胡杨(Populus euphratica Oliv.)是荒漠地区特有的珍贵森林资源,在中国的植物地理分布,以青海西部的柴达木盆地以西、昆仑山北麓、托拉海沿岸的河滩阶地和宁夏的阿拉善沙漠区为其东部界线。陕北和毛乌素沙地至今未见有关于胡杨天然林分布的报道。在不久前陕北靖边古大夏国都“统万城”遗址及周边的生态环境考察中,于无定河流域首次发现分布于这一地区的天然胡杨林。林地位于无定河上游沿岸二级阶地,为无定河水系与人工引水灌渠的平行地带,北边是无定河的一级阶地(河床滩地,现已被复耕),南面为二级阶地上的固定牧民庄户和围栏。土壤为黑沙土…     

水热因子对塔里木河下游胡杨年轮指数和植被指数的影响

【目的】探索塔里木河流域树木年轮与植被遥感间的关系。【方法】借助树木年轮学的方法和技术手段,利用塔里木河下游10个采样点的胡杨样芯数据和长时间序列中国植被指数(GIMMS NDVI)数据及水热因子数据,在分析该区胡杨年轮指数和植被指数变化特征基础上,重点探讨水热因子、胡杨年轮指数及归一化植被指数(NDVI)三者间的相关性。【结果】胡杨年轮指数和年际NDVI变化在1980—2001年间均呈下降趋势,区内植被在该时间段内退化较为严重。年内NDVI变化呈单峰状,5—8月为植被生长季,1—4月和9—12月为植被非生长季。【结论】该区胡杨年轮生长受5月(P<0.01, 显著负相关)地下水埋深和6月(P<0.01,显著负相关)温度影响显著,而NDVI主要与5—7月(P<0.01, 显著负相关)和10月(P<0.01, 显著负相关)的地下水埋深及7月(P<0.01, 显著负相关)温度有关,且影响NDVI和胡杨年轮指数的主要因子是水热因子中的地下水埋深因子。胡杨年轮指数与NDVI间的相关性差,未能通过0.05水平检验。     

胡杨径向生长与气候环境响应分析

 胡杨作为内陆干旱荒漠地区树龄较长的阔叶树种,是开展过去气候环境变化研究的宝贵材料.为了探讨胡杨树轮生长指标与气候环境之间的相关关系,本文在综述胡杨树种概况和生长区域气候环境特征的基础上,以新疆艾比湖流域胡杨为研究材料,利用树木年轮气候学分析方法,建立了艾比湖地区181年来的胡杨宽度年表.对宽度年表与精河、蔡家湖气象站的温度、降水序列进行了相关分析,结果表明,树轮宽度指标与冬半年降水呈正相关关系,相关系数最大为0.408,两个气象站中,精河站与年表相关系数高于蔡家湖站.通过与其他学者在该地区的研究成果对比分析,发现艾比湖胡杨树轮宽度指数高低时段与艾比湖湖面变化有很好的一致性,这与艾比湖地区地下水和湖面变化有密切关系,与胡杨生长受地下水变化影响的研究结论一致.     

利用数字填图系统“平面剖面图”功能实现展点和任意曲线的生成

在地质矿产调查过程中,会采集和分析很多的数据,通过分析数据或制作相应的图件来达到某种地质目的,其中利用数据制作相关的图件是地质工作中必不可少的工作,如基岩光谱曲线、地球化学剖面曲线等.笔者结合实际工作情况,利用数字填图系统中的“平面剖面图”功能来实现MapGIS展点和快速准确的生成各种曲线,利用该方法可为生产或研究工作节约时间,提高效率和图件质量,还可以拓展到其他方面进行应用.     

黑河下游荒漠河岸林植物水分传输观测试验研究

荒漠河岸林是长期适应干旱区内陆河流域环境的产物,具有独特的水分利用和生存策略.对黑河下游胡杨、柽柳等主要荒漠河岸林植物液流、水势、木质部导水率、根系水分再分配以及植物水分来源等的测试分析表明,在降水稀少、蒸发强烈的黑河下游,胡杨、柽柳主要利用的是深层土壤水和地下水,其中成熟胡杨主要吸收地下175~325cm处土壤水和地下水供其蒸腾和生存所需;胡杨根系水力提升过程主要发生在10~70cm土层,蒸散导致的土壤耗水量中有10%来自根系提升的水量;植物根和枝条木质部的初始导水率(K_(s0))和最大导水率(K_(s,max))相对较高,其中柽柳木质部的潜在导水能力比胡杨强;胡杨、柽柳液流速度呈单峰型,在午后达到峰值,黎明前水势无显著变化,反映未受到严重水分胁迫;黑河下游河道附近的地下水埋深大多在4m以内,基本可以满足荒漠河岸林植物的生长发育,黑河下游荒漠河岸林生态系统处于稳定和发展状态.     

Response of the accumulation of proline in the bodies of<Emphasis Type="Italic">Populus euphratica</Emphasis> to the change of groundwater level at the lower reaches of Tarim River

The content of proline in the plant bodies is closely related to the converse-succession-resistant capability of plants. Under the drought stress, the proline accumulates rapidly in the plant bodies for maintaining a certain mois-ture content and an expanding-pressure momentum in cells through the osmoregulation, thus the drought-resis- tant capability and the converse-succession-resistant ca-pability of plants are increased[1,2]. Many researches on the relationship between the proline and the…     

新疆艾比湖地区胡杨林生长监测方法研究

文章主要依据德国柏林工业大学生态学院景观与林业研究中心长期的实践经验监测形成的一套成熟的研究方法,对新疆艾比湖地区9个标准样地的胡杨林的生长情况进行准样地数据和树木数据监测,并提出其保护措施和方案。     

额济纳旗胡杨幼叶糖类物质变化

以额济纳国家级胡杨林自然保护区中两种不同样地中的胡杨幼叶为材料,进行可溶性糖和淀粉含量的变化研究,并对胡杨叶的形态结构的生长发育状况进行观测。实验结果表明:胡杨叶形态结构表现为随时间变化,叶的长、宽逐日增大,胡杨叶中可溶性糖的含量随时间变化而明显增大;淀粉含量则随时间变化呈略微增大趋势.在土壤含水量较低的样地,胡杨叶中可溶性糖含量较大,这是对干旱胁迫的一种适应.     

额济纳胡杨有性繁殖失败因素分析

对内蒙古额济纳绿洲胡杨种群的苗库状况、种子雨、种子生活力以及环境因子对种子萌发的影响进行了研究,结果表明:胡杨萌生苗占更新苗的绝大多数;胡杨能够产生出大量的有生活力的种子,胡杨种子散播时间在种群内部存在异质性;在恶劣的自然条件下,胡杨种子在落种后生活力迅速降低,(6-40)d后绝大部分种子(95%)会丧失活力。种子萌发试验表明:表土层含水量低、含盐量高、生化他感作用是胡杨种子萌发的限制性因子。由于胡杨种子属于短命种子,在其短暂的活力期内没有适宜的环境条件使之萌发,从而造成种子萌发失败。缺水所导致的种子安全萌发生境的缺失是额济纳胡杨的有性繁殖失败的首要原因。     

Analysis on water potential of Populus euphratica oliv and its meaning in the lower reaches of Tarim River, Xinjiang

Combined with materials measured on leaves water potential of Populus euphratica ofiv in the process of ecological water delivery in the lower reaches of Tarim River, the influence of ground-water depths and soil salinity on leaves water potential of P. euphratica was analyzed. We found that there was evident negative correlation between the leaves water potential of P. euphratica and ground-water depths. The deeper the ground-water depths were, the lower the leaves water potential of P. euphratica was, the more serious drought stress P. euphratica suffered from. Besides, there was evident negative correlation between the soil salinity and the leaves water potential of P. euphratica. The bigger the soil salinity was, the lower the leaves water potential of P. euphratica was, the more serious drought stress was indicated from which P. euphratica suffered. For sections rather distant for Daxihaizi Reservoir as well as for those places of wells rather distant from the river course, ground-water depths and the soil salinity were high; the leaves water potential of P. euphratica was low. The leaves water potential of P. euphratica can reflect the degree at which P. euphratica suffers from drought and salt stress, and has an important reference meaning in analyzing proper ground-water depths for the survival and growth of P. euphratic in the lower reaches of Tarim River.     

Analysis on water potential of Populus euphratica oliv and its meaning in the lower reaches of Tarim River,Xinjiang

Combined with materials measured on leaves water potential of Populus euphratica oliv in the process of ecological water delivery in the lower reaches of Tarim River, the influence of ground-water depths and soil salinity on leaves water potential of P. euphratica was analyzed. We found that there was evident negative correlation between the leaves water potential of P. euphratica and ground-water depths. The deeper the ground-water depths were, the lower the leaves water potential of P. euphratica was, the more serious drought stress P. euphratica suffered from. Besides, there was evident negative correlation between the soil salinity and the leaves water potential of P. euphratica. The bigger the soil salinity was, the lower the leaves water potential of P euphratica was, the more serious drought stress was indicated from which P. euphratica suffered. For sections rather distant for Daxihaizi Reservoir as well as for those places of wells rather distant from the river course, ground-water depths and the soil salinity were high; the leaves water potential of P. euphratica was low. The leaves water potential of P. euphratica can reflect the degree at which P. euphratica suffers from drought and salt stress, and has an important reference meaning in analyzing proper ground-water depths for the survival and growth of P. euphratic in the lower reaches of Tarim River.     

Analysis on water potential of Populus euphratica oliv and its meaning in the lower reaches of Tarim River,Xinjiang

Science Bulletin - Combined with materials measured on leaves water potential of Populus euphratica oliv in the process of ecological water delivery in the lower reaches of Tarim River, the...     

基于多源遥感的和田河流域生态补水对流域植被变化影响研究

利用Landsat遥感影像和MODIS数据集,得到和田河流域沙漠段河流水面面积和植被覆盖面积的时空分布特征．进一步分析归一化植被指数（NDVI）的季节变化特征与景观格局指数,得到和田河流域沙漠段生态环境的空间变化特征．结果表明:生态补水措施增加了流域的水体和植被面积,缓解了生态环境;并且生态补水后河流曲折系数下降,平均水面宽度增加,河流逐步朝平流化方向发展;NDVI的空间分布呈现河流两端植被覆盖量高,中间覆盖量低的特点．分析景观格局指数得到,生态应急补水使和田河流域沙漠段水体景观和植被景观分布呈现聚集分布,有效地缓解了生态环境．      

Physiological response of natural plants to the change of groundwater level in the lower reaches of Tarim River, Xinjiang

Based on the analysis of the three-year (2000-2002) monitoring data of the four times intermittent stream water conveyance to the lower reaches of Tarim River where the stream flow was dried up for more than 30 years and the measurement of PRO, SOD and POD in plants collected from 24 vegetation plots, it is concluded that the stream water conveyance plays an important role in lifting groundwater level. The groundwater nearby the watercourse was raised from 5～8 m in depth before the stream water conveyance to 2.5～5 m after stream water conveyance. The physiological response of Phragmites communis, Tamarix spp. And Populus euphratica to the change of groundwater is sensitive and represents a grads change obviously. The growth of the plants in the lower reaches of Tarim River is stressed by drought to various degrees. Lengthways, the drought stress exposed to the plants increases with groundwater depth from the upper sections to the lower sections; and breadthwise, the drought stress exposed to the plants is increased with the increase of distance away from the river channel of stream intermittent water releases and of the groundwater depth. Combining the field investigation and the analysis of the plots, it is considered that the stress groundwater depths for the Phragmites communis, Tamarix spp. And Populus euphratica are 3.5 m, 5 m and 4.5 m respectively.