The taphonomy of Last Glacial–Interglacial Transition (LGIT) distal volcanic ash in small Scottish lakes

Pyne‐O'Donnell, S. 2010: The taphonomy of Last Glacial–Interglacial Transition (LGIT) distal volcanic ash in small Scottish lakes. Boreas, 10.1111/j.1502‐3885.2010.00154.x. ISSN 0300‐9483. An extensive micro‐tephrostratigraphic survey of three small lakes in the Scottish Inner Hebrides was conducted encompassing the Last Glacial–Interglacial Transition (LGIT). The lakes are highly contrasting in terms of lake area to catchment ratio, the presence or absence of stream inlets draining the catchment, and in the complexity of the catchment drainage network. A suite of distal Icelandic volcanic ashes was consistently detected in all three lakes, with three, namely Penifiler Tephra, Vedde Ash and Ashik Tephra, being common to all the lakes. These ashes were chosen to examine the taphonomic intercomparability of ash location and concentration among the lakes. Findings reveal that the part played by catchment inlets in determining ash concentration and within‐basin location applies to microtephra layers as much as it does in studies of macrotephra layer thickness. The position of ash concentration maxima is also shown to vary significantly for different LGIT periods and may be a consequence of lake‐level changes, especially during the early Holocene. High‐resolution stratigraphic analysis through the Vedde Ash visible macrotephra at Loch Ashik reveals a high degree of complexity in taphonomic behaviour between the different geochemical components, with possible implications for the correct interpretation of the isochron position. The detection of multiple intact ash isochrons and the taphonomic processes responsible for their deposition should prove useful in future tephrostratigraphic surveys, as well as having applications within other palaeolimnological disciplines.     

Medium-scale hazard mapping for shallow landslide initiation: the Buyukkoy catchment area (Cayeli, Rize, Turkey)

The main purpose of this study is to develop a new hazard evaluation technique considering the current limitations, particularly for shallow landslides. For this purpose, the Buyukkoy catchment area, located in the East Black Sea Region in the east of Rize province and the south of Cayeli district, was selected as the study area. The investigations were executed in four different stages. These were (1) preparation of a temporal shallow landslide inventory of the study area, (2) assessment of conditioning factors in the catchment, (3) susceptibility analyses and (4) hazard evaluations and mapping. A total of 251 shallow landslides in the period of 1955–2007 were recognised using different data sources. A ‘Sampling Circle’ approach was proposed to define shallow landslide initiation in the mapping units in susceptibility evaluations. To accomplish the susceptibility analyses, the method of artificial neural networks was implemented. According to the performance analyses conducted using the training and testing datasets, the prediction and generalisation capacities of the models were found to be very high. To transform the susceptibility values into hazard rates, a new approach with a new equation was developed, taking into account the behaviour of the responsible triggering factor over time in the study area. In the proposed equation, the threshold value of the triggering factor and the recurrence interval are the independent variables. This unique property of the suggested equation allows the execution of more flexible and more dynamic hazard assessments. Finally, using the proposed technique, shallow landslide initiation hazard maps of the Buyukkoy catchment area for the return periods of 1, 2, 5, 10, 50 and 100 years were produced.     

青藏高原中部兹格塘错1970年来的湖面变化及原因初探

通过对位于青藏高原中部受人类活动影响微弱的兹格塘错1970-2006年湖面变化的分析,探讨了湖泊对气候变化的响应.从1970年的地形图,1977年MSS影像,1992年TM影像和2001年ETM+影像中提取的湖泊面积显示,湖泊有逐渐增大的趋势.1999年8月和2006年9月水深2 m处湖水中稳定离子K+和Cl-的浓度对比表明,湖水体积在这期间是增大的.近年来湖面持续上涨也得到了1998年8月,2002年8月和2006年9月野外实地考察的证实.通过分析兹格塘错附近那曲、班戈、安多气象站的记录发现,该区温度自1965年来呈明显上升趋势,表现在夏季(5-10月)和冬季(11月到次年4月)温度均有明显增高,冬季温度增幅更大.该区1965年来降水量也有增加的趋势,表现在夏季和冬季降水均有增加,但是夏季降水量增加幅度更明显.结合青藏高原1970年来最大蒸散和干燥度的变化,夏季和冬季降水量增加而蒸发量下降是导致兹格塘错湖面增大、湖水水位增高的主要原因.     

The use of magnetic measurements to investigate the mineralogy of Icelandic lake sediments and to study catchment processes

Magnetic measurements made on sediment and catchment samples from two contrasting Icelandic lakes show how susceptibility and saturation isothermal remanent magnetisation alter as magnetic minerals pass from rock to soil to stream and into the lakes. There is no detectable growth of secondary magnetic minerals in Icelandic soil profiles and susceptibility peaks in the 62.5–1000 μm size range of mineral particles in the lake sediments. Changes in sediment source can be detected using combinations of magnetic measurements.     

Lacustrine Record of 1954 Flood Event on Begnas and Rupa Lake,Central Nepal

In recent decades, there have been discussions and predictions regarding the impact of climate on floods, due to its socioeconomic and environmental consequences. For accurate prediction of future flood events and their impacts, it is crucial to have an improved understanding on past flood events. Lacustrine sediments have been used as a natural archive to study the past flood events. Here, we study the impact of 1954 flood event on the lacustrine environment of Bengas and Rupa Lake in central Nepal based on X-ray fluorescence spectrometry (XRF) element analysis, magnetic susceptibility (MS), total organic carbon (TOC) and the biomarker molecular compositions. Results showed that 1954 flood event had significant impacts on the two lakes in terms of detrital input, organic matter deposition and aquatic production. Before the flood event, both two studied lakes had relatively lower catchment erosion rate, lower organic matter deposition and aquatic production. During the flood event, catchment erosion and aquatic production increased in both lakes due to mass transport deposits and the increased nutrition loading attributed to flood event. Following the flood event, Begnas Lake showed the sharp increase in organic matter deposition, whereas in the Rupa Lake organic matter deposition showed minor changes. The difference in organic matter deposition in lakes during flooding event is likely due to detrital material brought and deposited by the flood activity. Overall our results suggest that lacustrine sediments are sensitive to the extreme event and would be an ideal archive for the reconstruction of flood events.     

Impacts of point source and diffuse metal and nutrient loading on three northern boreal lakes

A geochemical–paleolimnological study was conducted to investigate human influences on three lakes (Nuasjärvi, Jormasjärvi and Kolmisoppi) located in an area with high background levels of metals and sulphur in bedrock and till overburden. Accordingly, background concentrations of Co, Fe, Mg, Mn, Ni and Zn were above average in sediments of the study lakes.The land use-related erosion and transport of particulate matter into Lake Nuasjärvi started as early as in the seventeenth century, while increased inputs to Lake Jormasjärvi date to the eighteenth century and Lake Kolmisoppi to the 1970s and 1980s. Local tills and fine-grained sediments are the source of the particles and hydraulic sorting has resulted in elevated sediment concentrations of Ca, Cr, Cu, K, Mg, Na and Ni. At the same time, sedimentation of carbon and autochthonous phases has decreased, leading to low concentrations of Co, Fe and Mn in the erosion-associated sediment layers in Nuasjärvi and Kolmisoppi. Despite the geochemical changes, no marked eutrophication of the lakes could be detected with diatom-based nutrient reconstructions during the early land-use period.Elevated amounts of sulphur and chalcophilic elements were deposited throughout the study area during the 1970s and 1980s. In Lake Nuasjärvi combination of the elements is associated with the Lahnaslampi mine and the difference in the sulphide degradation rate is reflected as a sequence of element mobility and sedimentation in the order 1) S, and 2) Co, Ni, Cu, Zn, Cd and Sb. Sulphur, Cu, Ni, Pb and Zn enrichment in the other two lakes is related to other land uses and to atmospheric deposition. In addition to sulphur and metals, these most recent inputs from the catchment have caused nutrient enrichment in all three study lakes, most notably in the lowest-lying Lake Nuasjärvi. This lake has the highest percentage of fine-grained soils in its catchment and also suffers from point source nutrient inputs. In addition, metals (Ni) had a signal in diatom assemblages in Lake Nuasjärvi that was statistically independent of eutrophication (N:C) but inseparable from mineral matter inputs (K).     

The dynamic response of lakes in the Tuohepingco Basin of the Tibetan Plateau to climate change

The Tibetan Plateau (TP) is particularly sensitive to the influences of climate change. As indicators of climate change, lakes on the TP play a key role in the Earth’s climatic system. Lake Yazi (LY), Lake Tuohepingco (LT) and Lake Changtiao (LC) in the Tuohepingco Basin are three inland lakes on the plateau. The extents of LY, LT and LC were obtained using object-based image analysis for remote sensing and 22 images from Landsat satellites (from September to December between 1972 and 2015). Inter-annual changes in the extent of LY, LT and LC were then analyzed. The results show that the total area of the three lakes underwent a change from shrinkage to expansion between 1972 and 2015. In general, there was a trend toward shrinkage during 1972–1999, distinct expansion during 2000–2007 and slight expansion during 2008–2015. Moreover, we found that 14 other lakes have also expanded dramatically since 2000. Lakes at 30°N and 35°N (LY, LT and LC are also located in this region) exhibited the same dramatic period of expansion between 2000 and 2005. In other words, 2000 appears to be a critical transition point for changes in lake size on the TP. Lakes at the same latitudes in the Tibetan Plateau interior may have a similar period of dramatic expansion after 2000. The warming-triggered deglaciation or permafrost degradation, increased precipitation and decreased evapotranspiration may be the influencing factors of lake expansion in the Tuohepingco Basin. Temperature showed relatively higher correlation with lake extent, while precipitation and evaporation were slightly correlated with lake area. Given the importance of wetlands to human society, these are no trivial issues, and we now need accelerated research based on long-term and continuous remote sensing.     

Geochemical factors for endogenic mineral formation in the bottom sediments of the Tazheran lakes (Baikal area)

We studied recent sedimentation in small saline and brackish lakes located in the Ol’khon region (western Baikal area) with arid and semiarid climate. The lakes belong to the Tazheran system; it is a series of compactly located closed shallow lakes, with a limited catchment area and different mineralization, under the same landscape, climatic, geologic, and geochemical conditions. Two complementary approaches are applied in the research: (1) a detailed study of individual lake and (2) a comparison of the entire series of lakes, which can be considered a natural model for studying the relationship between endogenic mineral formation and the geochemistry of lake waters. The lake waters and bottom sediments were studied by a set of modern methods of geochemistry, mineralogy, and crystal chemistry. The mineral component of the bottom sediments was analyzed by powder X-ray diffraction (XRD), IR spectroscopy, and electron microscopy. The lakes are characterized by predominant carbonate sedimentation; authigenic pyrite, smectite, chlorite, and illite are detected in assemblage with carbonate minerals in the bottom sediments. Carbonate phases have been identified, and their proportions have been determined in the samples by decomposition of the complex XRD profiles of carbonate minerals into peaks using the Pearson VII function. Mathematical modeling of the XRD profiles of carbonates has revealed that predominantly Mg-calcites with variable Mg content and excess-Ca dolomite accumulate in lake bottom sediments influenced by biogenic processes. Aragonite, monohydrocalcite, and rhodochrosite form in some lakes along with carbonates of the calcite-dolomite series. We show a dependence of the composition of the assemblages of the newly formed endogenic carbonate minerals and their crystallochemical characteristics on the chemical composition of lake waters.     

Landslide susceptibility analysis based on ArcGIS and Artificial Neural Network for a large catchment in Three Gorges region,China

A landslide susceptibility map is very important and necessary to efficiently prevent and mitigate the losses brought by natural hazard for a large area. For the purpose of landslide susceptibility analysis for the whole Xiangxi catchment (3,209 km²), Artificial Neural Network (ANN) analysis was applied as the main method. The whole catchment was divided into two parts: the training area and the implementation area. The backwater area (559 km²) of Xiangxi catchment was used as the training area for the ANN method. In the training area the correlations between the landslide distribution and its causative factors, which includes lithology, slope angle, slope curvature and river network, have been analyzed based on the geological map and digital elevation model (DEM). The back-propagation training algorithm in ANN was selected to train the sample data from the training area, which were composed of input data (causative factors) and target output data (landslide occurrence), in order to find the correlations between them. Based on these correlations and input data in the implementation area (causative factors), the network output data were obtained for the implementation area. In the end, a map of landslide susceptibility, which was established by network output data, was presented for Xiangxi catchment. ArcGIS was applied to extract and quantify input information from a DEM for susceptibility analysis and also to present the result visually. As a result, a landslide susceptibility map, in which 70 % of all landslides are rightly classified in the training area (backwater area), was created for Xiangxi catchment.     

A review of Australian salt lakes and associated mineral systems

This study reviews the available information for over 1200 Australian salt lakes including in areas that have little or unreliable data. Publicly available groundwater hydrogeochemical datasets for the Australian arid zone are particularly sparse, inconsistent and of variable quality. Many datasets in the vicinity of salt lakes only report salinity or total dissolved solids, with no data for constituent cations and anions, and no appreciation of the hydrological and geomorphic evolution of the lakes. To overcome these limitations and to provide a broad-scale context, we developed mineral systems models to assess the potential of Australian salt lakes for potash, lithium and boron deposits. These models show that an important control on the potential of salt lake systems to form economic deposits of potash, lithium or boron is hydrogeological connectivity between leachable source rocks and the lakes. The assessment of the mineral potential was carried out in two stages. The first stage selection was based on the presence of favourable source rocks in the salt lakes’ catchments. The mean values of concentration in each catchment were derived from whole rock, sediment and groundwater geochemical datasets by averaging the values in samples (separately for each of the three datasets) located in the catchment and assigning this value to the catchment's salt lakes. The second stage selection was carried out by analysing available chemical data of groundwater in proximity to the salt lake systems delineated in the first stage. As a result, six regions were identified as having the highest potential, for potash in particular, but also for lithium and/or boron deposits. These are: the Lake Frome/Central Gawler Region of South Australia; two regions in the Northern Territory: the central western region extending into Western Australia, and the Lake Woods region; and, in Western Australia, the Lake Disappointment region, the north east Yilgarn and south east Yilgarn regions.     

Spatial and temporal geochemical variability in lacustrine sedimentation in the East African Rift System: Evidence from the Kenya Rift and regional analyses

Many previous studies on lacustrine basins in the East African Rift System have directed their attention to climatic controls on contemporary sedimentation or climate change as part of palaeoenvironmental reconstruction. In contrast, this research focuses on the impact of tectonism and volcanism on rift deposition and develops models that help to explain their roles and relative importance. The study focuses on the spatial and temporal variability in bulk sediment geochemistry from a diverse range of modern and ancient rift sediments through an analysis of 519 samples and 50 major and trace elements. The basins examined variously include, or have contained, wetlands and/or shallow to deep, fresh to hypersaline lakes. Substantial spatial variability is documented for Holocene to modern deposits in lakes Turkana, Baringo, Bogoria, Magadi and Malawi. Mio‐Pleistocene sediments in the Central Kenya Rift and Quaternary deposits of the southern Kenya Rift illustrate temporal variability. Tectonic and volcanic controls on geochemical variability are explained in terms of: (i) primary controlling factors (faulting, subsidence, uplift, volcanism, magma evolution and antecedent lithologies and landscapes); (ii) secondary controls (bedrock types, rift shoulder and axis elevations, accommodation space, meteoric and hydrothermal fluids and mantle CO ₂); and (iii) response factors (catchment area size, orographic rains, rain shadows, vegetation densities, erosion and weathering rates, and spring/runoff ratios). The models developed have, in turn, important implications for palaeoenvironmental interpretation in other depositional basins.     

Monitoring of Dead Sea water surface variation using multi-temporal satellite data and GIS

Remote sensing (RS) and geographic information systems (GIS) are very useful for environmental-related studies, particularly in the field of surface water studies such as monitoring of lakes. The Dead Sea is exposed to very high evaporating process with considerable scarcity of water sources, thus leading to a remarkable shrinkage in its water surface area. The lake suffers from dry out due to the negative balance of water cycle during the previous four decades. This paper discusses the application of RS, GIS, and Global Positioning System to estimate the lowering and the shrinkage of Dead Sea water surface over the period 1810–2005. A set of multi-temporal remote sensing images were collected and processed to show the lakes aerial extend shrinkage from 1973 up to 2004. Remote sensing data were used to extract spatial information and to compute the surface areas for Dead Sea for various years. The current study aims at estimating the fluctuation of Dead Sea level over the study period with special emphasis on the environmental impact assessment that includes the degradation level of the Dead Sea. The results indicated that there is a decrease of 20 m in the level of the Dead Sea that has occurred during the study period. Further, the results showed that the water surface area of the Dead Sea has shrunk from 934.26 km² in 1973 to 640.62 km² in 2004.     

A multi‐proxy study of Holocene lake development,lake settlement and vegetation history in central Ireland

Stratigraphical investigations, geomorphological mapping, and diatom, plant macrofossil and pollen analyses were undertaken in and around two lakes in central Ireland to establish correlations between changes in lake conditions and catchment vegetation throughout the Holocene. Similar investigations of an adjacent mire reveal early Holocene changes in lake level and area. The palaeoecological data show high correlations related to variations in lake depth and area, catchment vegetation type, organic inputs and trophic status. Catchment‐scale deforestation is gradual and occurs through the Bronze and the Iron Ages, and the construction of a crannog in the early Medieval period (seventh century AD ) appears to be associated with a widespread increase in deforestation and mixed agriculture in the catchment. Both pollen and plant macrofossils suggest that one of the crannogs was used for crop storage in addition to domestic and any other activities. In the early to middle Holocene similarities in the proxy‐data appear to be climatically driven through changing lake levels and areal extent whereas the later Holocene record is clearly dominated by anthropogenic changes within the catchment and the construction of crannogs in the lakes. The advantages of combining multi‐proxy indicators of lake hydroecology with the vegetation record are illustrated. Copyright © 2005 John Wiley & Sons, Ltd.     

Geomorphological,pedological, and hydrological characteristics of karst lakes at Conversano (Apulia,southern Italy) as a basis for environmental protection

The land around Conversano (Apulia, southern Italy) is part of the Murge karst, interesting limestones and dolomitic limestones of Upper Cretaceous age, in a flat environment with sub-horizontal setting. Dolines and karst depressions are the most typical landforms in the area. Filling of these landforms with eluvial deposits locally created the possibility of water stagnancy at the surface. The Conversano territory presents ten karst lakes that represented, until some decades ago, the only water resource available for the local people, who built the typical bell-shaped wells to collect water volumes satisfying local needs during the dry season. Currently, these lakes have no great importance as water supplies, but represent habitats of great naturalistic value that are still able to support the ecological functionality and the wet environments with self-vegetation. Hydrological and hydrogeological studies have been carried out with the aim to fully estimate the related environmental problems. For this purpose, the hydrogeologic data of historical time series have been collected and compared to those of the last 5 years; successively, according to the Thornthwaite method, a hydrological monthly balance has been evaluated to quantify the distribution of water volumes interacting annually between the surface water bodies and the underlying carbonate groundwater. This evaluation has highlighted the need to carefully consider all the parameters concurring to a right definition of water balance for a karst environment, where pedological features, climatic conditions and anthropogenic modifications to the environment represent the elements of a very delicate system. Particularly, on the basis of recent soil map and field surveys, a re-evaluation of the available water capacity, estimated in some 40 mm, has been carried out. The studies have highlighted the need to extend the environmental protection rules to larger areas around the lakes, e.g. at the catchment scale, with definition of buffer zones; in this manner, it will be possible to constantly monitor the protected land and the local anthropogenic activities, that represent real polluting sources for both the surface water resources and the underlying carbonate groundwaters.     

Key techniques for the emergency disposal of Quake lakes

The Wenchuan Earthquake of May 12, 2008 formed a large number of Quake lakes; 104 of them had a dam taller than 10 m, a water storage capacity larger than 1.0 × 10⁵ m³, and a catchment area greater than 20 km². If these Quake lakes are not thoroughly assessed and properly disposed, the losses caused by the burst of these lakes may be even larger than those caused by this earthquake itself. The Quake lakes with high risks have been properly disposed with the schemes proposed by the authors. This article presents a case study on the emergency disposal of the Tangjiashan, Laohuzui, Jiadanwan, and other Quake lakes. The key techniques applied in the emergency disposal of Quake lakes, including site exploration, risk assessment, design of discharge chutes, selection of construction method and equipment as well as post-emergency disposal evaluation, are discussed.     

Models to predict water chemical cluster variables

This study is an attempt to quantify and rank variables of significance to predict mean values of lake pH and related variables (alkalinity, conductivity, hardness, etc.) in small glacial lakes. The work is based on a new and extensive set of data from 95 Swedish lakes and their catchment areas. Several empirical models based on catchment and lake morphometric parameters have been presented. These empirical models can only be used to predict mean values of these variables for lakes of the same type, and these models based on geological map parameters can evidently not be used for highly time-dependent and site-typical predictions. Various hypotheses concerning the factors regulating the mean values of the cluster variables were formulated and tested. Different statistical tests were used to separate random influences from causal. The most important map parameters were: the percent of rocks and open (=cultivated) land in the so-called near area to the lake [as determined with the drainage area zonation (DAZ) method], mean depth, linked to resuspension and the form and size of lakes, relief of the drainage area and lake area. Each of these variables only provides a limited degree of (statistical) explanation of the variability in mean annual values of pH and the water chemical cluster variables among the lakes. The predictability of some of the models can be markedly improved by accounting for the distribution of the characteristics in the drainage area. The variability in mean annual values of pH (and related variables) from other parameters, such as specific anthropogenic load, etc., may then be quantitatively differentiated from the impact of these geological parameters. This paper also gives a simple method to estimate natural, preindustrial reference values of these water chemical variables from the presented models.     

Sedimentary facies and geomorphic evolution of a blocked‐valley lake: Lake Futululu,northern Kwazulu‐Natal,South Africa

Blocked‐valley lakes are formed when tributaries are impounded by the relatively rapid aggradation of a large river and its floodplain. These features are common in the landscape, and have been identified in the floodplains of the Solimões‐Amazon (Brazil) and Fly‐Strickland Rivers (Papua New Guinea), for example, but their inaccessibility has resulted in studies being limited to remotely sensed image analysis. This paper documents the sedimentology and geomorphic evolution of a blocked‐valley lake, Lake Futululu on the Mfolozi River floodplain margin, in South Africa, while also offering a context for the formation of lakes and wetlands at tributary junctions. The study combines aerial photography, elevation data from orthophotographs and field survey, and longitudinal sedimentology determined from a series of cores, which were sub‐sampled for organic content and particle size analysis. Radiocarbon dating was used to gauge the rate and timing of peat accumulation. Results indicate that following the last glacial maximum, rising sea‐levels caused aggradation of the Mfolozi River floodplain. By 3980 years bp , aggradation on the floodplain had impounded the Futululu drainage line, creating conditions suitable for peat formation, which has since occurred at a constant average rate of 0·13 cm year^?1. Continued aggradation on the Mfolozi River floodplain has raised the base level of the Futululu drainage line, resulting in a series of back‐stepping sedimentary facies with fluvially derived sand and silt episodically prograding over lacustrine peat deposits. Blocked‐valley lakes form where the trunk river has a much larger sediment load and catchment than the tributary stream. Similarly, when the relative difference in sediment loads is less, palustrine wetlands, rather than lakes, may be the result. In contrast, where tributaries drain a steep, well‐connected catchment, they may impound much larger trunk rivers, creating lakes or wetlands upstream.     

近20a来西藏朋曲流域冰湖变化及潜在溃决冰湖分析

全球气候变暖,青藏高原冰川普遍处于退缩趋势,由此引发的冰湖溃决洪水的灾害也随之增加.通过对2000/2001年度卫星遥感数据解译结果和1987年国际联合考察的朋曲流域冰湖溃决洪水结果的分析,研究了近20a来朋曲流域内冰湖的变化.结果显示,该流域中的冰湖数量有减少,但冰湖的面积却在增加,这是同期全球气候变暖的结果.在提供了冰湖编目数据的基础上,识别了有潜在危险的冰湖,为冰湖溃决洪水早期预警系统提供了科学依据.     

1995-2015年全球不同气候带典型冰川补给型湖泊动态变化

基于1995年、2005年和2015年3期Landsat影像数据,利用遥感和地理信息系统技术,分析全球不同气候带典型冰川补给型湖泊面积、数量及其对气候变化的响应。结果表明:①1995-2015年全球典型冰川补给型湖泊面积增加了2.32%,数量减少了2.26%,其中以小型湖泊（< 1 km2）和大型湖泊（>50 km2）面积变化最为剧烈,中型湖泊（1~50 km2）面积则相对稳定,1995-2005年冰川补给型湖泊面积与数量的变化速率相比2005-2015年较快。②1995-2015年热带、亚热带、温带冰川补给型湖泊面积与数量均在增加,其中以热带冰川补给型湖泊变化最为剧烈,其面积上升了20.62%,数量上升了25.32%,亚寒带与寒带冰川补给型湖泊面积与数量均减少,其中以寒带冰川补给型湖泊变化最为明显,其面积减少了11.3%,数量下降了18.97%。可为全球典型冰川补给型湖泊的变化及其影响因素的后续研究提供依据和参考。     

Abrupt Change of Lake Environment in West China:an Evidence for Global Climate Warming

ABRUPT CHANGE OF LAKE ENVIRONMENT IN WEST CHINA: AN EVIDENCE FOR GLOBAL CLIMATE WARMINGtheNational(G19980 4 0 80 2 )andCAS’sKeyProjectonTibetanPlateauResearch(KZ951 A1 2 0 4 )