中国东西部平原区湖泊近期变化之比较

本文通过对中国部湖泊近期演化及其对环境影响的比较研究，认为导致东西部湖泊近期大面积退缩的主要原因都是人类活动。平原区湖泊的许多传统功能正逐渐被水利工程所取代，今后湖区资源的开发应充分注意这一趋势。     

波兰湖泊面积变化因素

摘波兰北部有众多斯堪的纳维亚冰盖冰期形成的湖泊。通过湖泊区的研究,发现湖泊面积在逐渐减少,甚至导致消失．本文对变化的程度进行了观测,指出影响波兰湖泊面积变化的主要自然与人为因素,包括气候变化、湖盆深度、生物量增长、森林砍伐、水利工程建修、农药利用和排污等。     

近40 a巴丹吉林沙漠腹地湖泊面积变化及其影响因素

 利用1973、1990、2000年和2010年4期Landsat遥感影像资料为信息源,运用目视解译和波段比值的方法得到不同时相巴丹吉林沙漠腹地湖泊信息,分析其变化特征,结合沙漠周边降水数据,通过水量收支平衡关系对湖泊群变化因素进行了初步探讨。结果表明,沙漠湖泊在各时期发生了不同程度的萎缩。1973—2010年间,湖泊总数由94个减少到82个,共减少了12个,总面积减少了3.69 km2。其中,1973—1990年间湖泊萎缩最快。对沙漠湖泊面积进行统计分级后发现,湖泊的萎缩主要发生在面积小于0.2 km2的湖泊中,萎缩速率由快到慢;面积大于0.9 km2的湖泊面积发生不同程度的波动。湖泊群面积变化基本不受人为因素影响,也不是当地气候变化直接作用的结果,地下补给源水量变化是导致湖泊面积变化的主要因素。     

湖泊水文情势变化及其生态响应概述

湖泊水文情势(幅度、频率和持续时间)是湖泊生态系统的主要影响因素之一,理解湖泊水位变化的生态响应机制对制定有效的生态水位调控策略具有重要意义。从湖泊水位变化的时间尺度,水位变化对湖泊物理环境的影响,以及水位变化对湖泊大型植物、底栖藻类、大型底栖动物、鱼类和鸟类的影响等方面论述湖泊水位变化的生态后果,为实现湖泊水位的生态调控提供参考。     

内蒙古黄旗海不同粒级湖泊沉积物Rb、Sr组成与环境变化

Based on the geochemical elements Rb and Sr in sediments with three different grain size fractions from profile H3 on the northern lacustrine bottomland 13 m above the Huangqihai Lake surface in 1986,the paper investigates the record of palaeolake stand state, sedimentary environmental evolution,and winter monsoon change.First,these samples are separated into three different grain size fractions,i.e.,total sediments,77-20μm and〈20μm. Second,the chemical elements-Rb and Sr-of the grain size separation were tested and analyzed systematically in this paper.Then the elements compositions of these samples are measured using VP-320 mode fluorescence spectrum instrument,respectively.The magnetic susceptibility of these samples is measured using Kappabridge KLY-3 mode instrument made in Czech AGICO Company.The results showed the elements and the ratios varied regularly with the grain size.But the ratio of Rb/Sr in the sediments〈20μm correlates positively with the magnetic susceptibility of these samples.Therefore,the ratio of Rb/Sr in the fraction〈20 μm from the lake sediments reflected the strengthening of the weathering in the deposition sites.It is a good indicator of the summer monsoon-induced weathering and pedogenesis fluctuations and can be used to reconstruct the conditions of the paleoclimate and paleoenvironment.     

天山冰川与湖泊变化所示的气候趋势

天山山系深居亚洲大陆腹地，受中亚自然地理环境的制约，在变性西风气流的影响下，７０年代至今山地冰物质平衡负值，伴随着气温的变化而增大。湖泊则是随着山区降水量的增加，其面积渐增。气温与降水的相互作用，使得整修天山山系的水资源总量趋于正常略偏多。预期这种气候趋势将会延续到下世纪初期。     

烧失量分析在湖泊沉积与环境变化研究中的应用

烧失量分析是一种便捷的测定湖泊沉积物有机碳与碳酸盐含量的方法。由于沉积物烧失量主要受区域气温、有效降水等气候环境条件的控制,因此烧失量反映湖泊气候环境特征,成为指示区域气候环境变化的重要指标,该项指标在环境变化研究中具有重要作用。     

1986—2020年库布齐沙漠湖泊数量和面积

沙漠湖泊动态变化研究对于揭示区域水循环和了解沙漠生态环境具有重要意义。本文利用1986—2020年覆盖库布齐沙漠区域10期Landsat TM/OLI遥感影像提取沙漠湖泊,统计各时期沙漠湖泊数量和面积变化信息,分析库布齐沙漠湖泊数量和面积动态变化的空间特征。结果表明：库布齐沙漠湖泊数量与面积整体表现为减小趋势,现存湖泊22个,面积7.4678 km²;库布齐沙漠湖泊在1986—2020年共干涸26个,现存湖泊中众多小型湖泊呈现增长趋势,但面积较小,对整个库布齐沙漠湖泊的影响较小,>1 km²湖泊中的大青龙湖、天鹅湖以及大道图湖表现为萎缩状态,减少幅度较大,对整个库布齐沙漠湖泊影响较大;降水量、蒸发量和气温不是影响库布齐沙漠湖泊面积变化的主要因素,湖泊面积的空间特征可能由补给来源、补给方式及人为干扰造成。     

近40 年可可西里地区湖泊时空变化特征

以可可西里地区1970s 地形图和1990s、2000-2011 年Landsat TM/ETM+遥感影像为基础,通过数字化和影像解译获取研究区83 个面积大于10 km²湖泊变化数据,并对湖泊变化成因进行了分析。研究结果表明:1) 1970s 初期至2011 年,可可西里地区湖泊经历了“先萎缩后扩张”的变化过程,其中1970s-1990s 期间湖泊面积普遍减小,1990s-2000 年湖泊出现扩张,并在2000 年恢复到1970s 湖泊规模,2000 年之后湖泊面积急剧增大。2) 2000-2011 年间,可可西里地区不同规模等级湖泊整体呈扩张趋势,但表现出一定的区域差异性。面积呈增加趋势的湖泊数量最多,亦分布最广,一些湖泊由于扩张迅速出现湖泊合并或湖水外泄情况;面积呈减少趋势或波动起伏的湖泊数量较少,零散分布在研究区中部和南部,湖泊动态变化与其自身补给条件或与下游湖泊(河道) 存在水力联系有关。3) 在研究时段内,降水增多、蒸发减少是可可西里地区湖泊扩大的主要原因,而气候变暖引起的冰川融水增加、冻土水分释放是次要原因。     

次生化学成因碳酸盐含量在湖泊环境变化研究中的应用与进展

湖积物中次生化学成因碳酸盐含量受控于包括温度、水分在内的众多因素,其变化可反映环境、气候及构造信息。根据影响碳酸盐含量变化主要因素的不同,可将其归纳为几种模型:水分-温度主控模型、水分主控模型、温度主控模型及其它因素主控模型,并进行了述评。     

呼伦贝尔草原沙漠化土地动态变化过程研究

对呼伦贝尔草原4个时期的遥感监测表明：呼伦贝尔草原经历了“发展—加速发展—逆转”的沙漠化过程;1984—2000年也是研究区沙漠化发展最为迅速的时期,沙漠化土地增加率为72.1 km²·a^-1;2000年以后,沙漠化土地进入逆转时期,且沙漠化土地以32.4 km²·a^-1的速度减少;沙漠化的发生、发展主要是由于冻土退化及温度升高导致的地表干旱和不合理的人为活动共同作用的结果。而2000年以后沙漠化的逆转,则是一系列有效的沙漠化治理措施的结果。但是研究区人口和牲畜持续增加使土地的压力增加,这造成研究区北部的草地发生了沙漠化,同时,严重沙漠化土地持续增加。减轻土地压力才是沙漠化治理的根本途径。     

呼伦贝尔沙质草原风蚀坑形态发育模式分析

 野外调查测量呼伦贝尔沙质草原风蚀坑分布和形态参数,根据不同发展阶段的风蚀坑形态特征的差异、形态参数间相关关系和拟合结果分析了风蚀坑的形态演变和发育、成因、规律。发现不同发展阶段风蚀坑形态参数之间的控制关系和扩展模式不同,各形态参数之间具有较好的幂函数关系。对于风蚀坑的侵蚀坑而言,坑长增长速度最快,其后依次是坑宽和坑深,坑后积沙体具有类似规律。风蚀坑坑后积沙的3个形态参数,受侵蚀坑3个参数的联合控制,但受坑深的控制最为显著。风蚀坑出现的起始形态、地形特征、植被、气流场、气候条件、人类活动的扰动等对其形态和发育具有重要影响,并且形态和发育反作用于植被、气流等,形成形态与气流、植被之间的响应与反馈。     

Landscape pattern change and driving force of blowout distribution in the Hulun Buir Sandy Grassland

The land coverage pattern changes for the past 50 years in a typical region of the Hulun Buir Sandy Grassland were interpreted and analyzed based on a series of remote sensing images in 1959, 2002, 2004 and 2009. The temporal and spatial changes of landscape patterns were revealed and the driving forces were analyzed. The results show that all land coverage types had large variable amplitudes. The grassland area decreased, whereas other areas increased. Owing to implementation of artificial sand fixation from 2004 to 2009, the areas of flowing blowouts and depositional area decreased by 71,369 and 128,835 m², respectively. The average patch area reduced, but the number of blowouts increased, fractal dimension increased, and blowout structure became complex. The fragmentation index increased, whereas contagion index decreased. Driving force analysis shows that human factors such as overgrazing are slightly larger than natural factors of increased temperature and decreased precipitation.     

呼伦贝尔沙地治理布局及治理模式

本文依据呼伦贝尔沙地自然状况和生态建设工程的实际情况,按照统筹规划的原则,将呼伦贝尔沙地划分为5个治理区:沙地樟子松林治理区、森林-草原过渡带沙地综合治理区、北部沙地治理区、中部沙地治理区、西部零散沙地治理区;提出了6种适合呼伦贝尔沙地的治理模式:沙地樟子松封育模式、灌-草方格状混播模式、植苗造林治沙模式、机械沙障与灌-草混播模式、樟子松野生大苗移栽固沙模式、高立式沙障治理模式;针对5个治理区内的不同立地类型,提出了相应的优化治理模式。     

呼伦贝尔沙质草原碟形风蚀坑表面气流及其意义

呼伦贝尔沙质草原风蚀坑发育于宽单峰中能风况环境,是该区主要风沙地貌类型。对碟形坑表面气流的观测结果显示,气流进入风蚀坑后,在入风口扩散,风速开始降低至坑底达到最低;在坑后缘出风口汇集形成急流,风速剧增至坑后积沙顶部风速达到最高值。风蚀坑后缘在风沙流的磨蚀作用下后退,风蚀坑顺风向扩展,同时此处较大的剪切风速和输沙率使大量来自坑内的沙物质沉积到坑后草地上呈扇状蔓延。呼伦贝尔沙质草原风蚀坑在来自西北、西和西南方向风的交替作用下,向东南、东和东北方向扩展而生成。随着风蚀坑深度和水平尺度的增加,最终可能沿强风能方向或合成输沙方向扩展成为大型的槽形坑。     

呼伦贝尔沙地紫外辐射和太阳总辐射特征

利用呼伦贝尔沙地鄂温克自治旗2019年观测的辐射资料,对该地区的紫外辐射和总辐射进行了初步分析.结果表明:紫外辐射、总辐射年变化位相基本相同,年曝辐量分别为240.33、5 142.41 MJ·m-2,年均日曝辐量分别为0.66、14.09MJ.m-2,紫外辐射年均日曝辐量小于西藏拉萨地区;紫外辐射辐照度和总辐射辐照度...     

呼伦贝尔沙地风蚀坑粒度特征及其环境意义

对呼伦贝尔沙地现代风蚀坑表层沙质沉积物与坑后沙丘垂直剖面沉积物进行了粒度分析,讨论了坑后沙丘剖面的形成过程及风成沙粒度变化的原因。结果表明：呼伦贝尔沙地风蚀坑表面及坑后沙丘剖面沉积物粒径以细沙和中沙为主;风蚀坑表面沉积物粒径及分选参数在风蚀坑各部位呈现波动式变化;平坦草地上的现代土壤与坑后沙丘下伏古土壤为同一层。基于粒度和沙丘移动过程综合分析,认为坑后沙丘剖面中风成沙粒度的垂向变化与沙丘在堆积和移动过程中剖面在坑后沙丘相对位置的变化具有紧密联系,密集采样得出的剖面中风成沙粒度的垂向变化是否能直接指示区域气候环境变化值得商榷。     

30年来呼伦贝尔地区草地植被对气候变化的响应(英文)

Global warming has led to significant vegetation changes especially in the past 20 years. Hulun Buir Grassland in Inner Mongolia, one of the world’s three prairies, is undergoing a process of prominent warming and drying. It is essential to investigate the effects of climatic change (temperature and precipitation) on vegetation dynamics for a better understanding of climatic change. NDVI (Normalized Difference Vegetation Index), reflecting characteristics of plant growth, vegetation coverage and biomass, is...     

30年来呼伦贝尔地区草地植被对气候变化的响应(英文)

Global warming has led to significant vegetation changes especially in the past 20 years. Hulun Buir Grassland in Inner Mongolia, one of the world’s three prairies, is undergoing a process of prominent warming and drying. It is essential to investigate the effects of climatic change (temperature and precipitation) on vegetation dynamics for a better understanding of climatic change. NDVI (Normalized Difference Vegetation Index), reflecting characteristics of plant growth, vegetation coverage and biomass, is used as an indicator to monitor vegetation changes. GIMMS NDVI from 1981 to 2006 and MODIS NDVI from 2000 to 2009 were adopted and integrated in this study to extract the time series characteristics of vegetation changes in Hulun Buir Grassland. The responses of vegetation coverage to climatic change on the yearly, seasonal and monthly scales were analyzed combined with temperature and precipitation data of seven meteorological sites. In the past 30 years, vegetation coverage was more correlated with climatic factors, and the correlations were dependent on the time scales. On an inter-annual scale, vegetation change was better correlated with precipitation, suggesting that rainfall was the main factor for driving vegetation changes. On a seasonal-interannual scale, correlations between vegetation coverage change and climatic factors showed that the sensitivity of vegetation growth to the aqueous and thermal condition changes was different in different seasons. The sensitivity of vegetation growth to temperature in summers was higher than in the other seasons, while its sensitivity to rainfall in both summers and autumns was higher, especially in summers. On a monthly-interannual scale, correlations between vegetation coverage change and climatic factors during growth seasons showed that the response of vegetation changes to temperature in both April and May was stronger. This indicates that the temperature effect occurs in the early stage of vegetation growth. Correlations between vegetation growth and precipitation of the month before the current month, were better from May to August, showing a hysteresis response of vegetation growth to rainfall. Grasses get green and begin to grow in April, and the impacts of temperature on grass growth are obvious. The increase of NDVI in April may be due to climatic warming that leads to an advanced growth season. In summary, relationships between monthly-interannual variations of vegetation coverage and climatic factors represent the temporal rhythm controls of temperature and precipitation on grass growth largely.     

呼伦贝尔沙地沙丘砂来源的定量分析--逐步判别分析(SDA)在粒度分析方面的应用

Quantltatively determining the sources of dune sand uis one of the problems necessarily and urgently to be solved in aeolian landforms and desertification research. Based on the granulometric data of sand materials from the Hulun Buir Sandy Land, the paper employs the stepwise discriminant analysis technique (SDA) for two groups to select the principal factors determining the differences between surface loose sediments. The extent of similarity between two statistical populations can be described quantitatively by three factors such as the number of principal variables, Mahalanobis distance D^2 and confidence level α for F-test. Results reveal that: 1) Aeolian dune sand in the region mainly derives from Hailar Formation (Q3), while fluvial sand and palaeosol also supply partially source sand for dunes; and 2) in the vicinity of Cuogang Town and west of the broad valley of the lower reaches of Hailar River, fluvial sand can naturally become principal supplier for dune sand.