high altitude aeolian research on the tibetan plateau aeolian processes and their role in desertification have been studied extensively at low elevations but have been rarely studied at high elevations in areas such as the tibetan plateau where aeolian processes were active in the geologic past and remain active today in this review we summarize research that improves our understanding of aeolian processes on the tibetan plateau including the distribution characteristics and provenance of aeolian sediments the history of aeolian activity aeolian geomorphology and wind driven land degradation contemporary aeolian processes primarily occur in dry basins in wide river valleys on lakeshores on mountain slopes and on gravel pavements sediment characteristics suggest a local origin and provide interesting contrasts with those of china s loess plateau the history of aeolian activity and its paleoclimatic implications reconstructed based on aeolian archives is short mostly since the late glacial and shows wide regional differences aeolian geomorphology is simple and suggests short formation time wind driven land degradation is less severe than previously thought driven by different factors in different areas and exhibited complex interactions with freeze thaw processes aeolian research has been conducted within the general framework of aeolian science but addresses issues specific to the tibetan plateau that arise due to the low air temperature low air density and the presence of a cryosphere we propose six priorities for future research aeolian physics the effect of freeze thaw cycles comparisons with other areas regional differences effects of wind driven land degradation and integrated observation and monitoring

hydrogeological and geotechnical assessments of the kadifekale landslide area izmir turkey the study area is located in the south of izmir city centre in an area built without planning permission or any overall city plan in this area a number of mass movements occurred in the past and the region is still an active landslide field at present the real sliding factor is geological structure which is made up of hard volcanic rocks overlying soft neogene clayey soils and forms a typical structure prone to sliding unplanned human activities change the hydrogeological and geotechnical stabilities of the geological formations in a negative way rain and water leaking either directly from the mains or septic holes infiltrate into the ground and act as one of the factors in causing landslides it is clearly shown that the irregular urbanization in and around kadifekale is one of the factors contributing to the landslides in the area to prevent the occurrence of landslides in the study area an effective surface and under ground drainage should be established rain and wastewater should be removed from the area by separate systems slopes should be reduced water loving trees should be planted and construction of high rise buildings should be avoided

a high resolution atmospheric dust record for 1810 2004 a d derived from an ice core in eastern tien shan central asia centennial scale high resolution records of atmospheric dust conditions are rare in the arid and semiarid regions of central asia limiting our understanding of the regional climate and environmental changes and their potential driving forces in this paper we present an annually resolved atmospheric dust record covering the period of 1810 2004 a d reconstructed from an ice core retrieved at 4512 m above sea level from the miaoergou glacier in the eastern tien shan the time series of dust flux for the past 195 years shows three periods of relatively low values i e 1810 1829 a d 1863 1940 a d and 1979 2004 a d and two periods of relatively high values i e 1830 1862 a d and 1941 1978 a d spatial correlation analysis suggests possible regional factors controlling the dust flux including antecedent summer precipitation spring soil moisture and near surface wind speed in addition the miaoergou dust flux is closely associated with the winter index of the north atlantic oscillation nao over the past two centuries with high low dust periods coinciding with the negative positive phases of the nao the persistent relationship suggests that the nao may have been a key driver on dust flux change over the arid regions between the tien shan and kunlun mountains

why is there an early spring cooling shift downstream of the tibetan plateau abstract the temperature shift over the eastern flank of the tibetan plateau is examined using the last 50 yr of chinese surface station observations it was found that a strong cooling shift occurs in early spring march and april and late summer july august and september in contrast to the warming shift in other seasons the cause of the march april ma cooling is investigated in this study the ma cooling shift on the lee side of the tibetan plateau is found to be not a local phenomenon but rather it is associated with an eastward extension of a cooling signal originating from north africa that is related to the north atlantic oscillation nao in the previous winter the midtropospheric westerlies over the north atlantic and north africa tend to intensify during positive nao phases the enhanced westerlies after passing over the tibetan plateau result in strengthened ascending motion against the lee side of the plateau which favors the formation of midlevel stratiform clouds the increased a

effects of lithology and geomorphology on sediment yield in karst mountainous catchments abstract due to the characteristics of the lithology and the complexity of the geomorphology the karst areas of southwest china are experiencing severe soil erosion knowledge of the effects of lithology and geomorphology on sediment yield are therefore essential for developing measures to effectively control sediment delivery in this region the objective of this study was to investigate the relative importance of lithological and geomorphological factors for sediment yield in 40 selected karst mountainous catchments in southwest china because of the high co dependence of these variables a partial least squares regression plsr model was used to explore the quantitative relationships between annual sediment yield and 30 lithological and geomorphological factors results showed that the lithology and geomorphology were critically important to annual sediment yield and could explain 65 9 of the total variance in sediment yield the dominant lithological and geomorphological factors controlling annual sediment yield were karst coverage drainage density basin relief plane curvature elevation maximum elevation average slope dolomite coverage relative relief and catchment area this importance or these contributions of lithological and geomorphological factors to annual sediment yield provides a good reference for selecting key factors when developing soil erosion models this study yields a greater understanding of the influences of lithology and geomorphology on sediment yield and is helpful for better catchment management in karst regions

dust storm activity over the tibetan plateau recorded by a shallow ice core from the north slope of mt qomolangma everest tibet himal region 1 based on a 39 8 m ice core drilled at the east rongbuk glacier 27 59 n 86 55 e 6518 m a s l north slope of mt qomolangma everest central himalaya the changes of dust storm over the tibetan plateau tp recorded by insoluble particle and its possible connection with the winter jfm north atlantic oscillation nao are investigated the results show that the level of dust storm activity exhibits a significant decreasing trend during the past 50 years this may be attributed at least partly to a decrease in wind speed over the tp and its surrounding regions the normalized time series of the winter nao index shows a significant inverse correlation with the mass concentration of insoluble particle implying a possible connection between the winter nao and the dust storm activity over the tp

a holocene record of atmospheric dust deposition on the penny ice cap baffin island canada a holocene record of atmospheric dust deposition on the penny ice cap baffin island canada

reconstructing dust storm frequency in china since 1617 ce using coral based estimates of sea surface temperature abstract dust storms occur frequently in arid and semi arid regions of china and other parts of the world exerting a considerable influence on air quality in densely populated areas instrumental observations of dust storms are only available over the past 50 to 60 years limiting our ability to understand dust storm variability over longer timescales however tropical sea surface temperatures have been reconstructed over the past four centuries using geochemical records from corals here we show that tropical pacific sea surface temperatures as recorded by corals can be used to reconstruct dust storm frequency at one year resolution based on the coral reconstructed annual sea surface temperature anomaly data from two regions the western pacific 25 n 25 s 110 155 e and the eastern pacific 10 n 10 s 175 e 85 w published by tierney et al 2015 we reconstructed the frequency of dust storms in northern china dsfcn for the period from 1617 to 1953 ce the reconstructed dsfcn variation can be divided into several distinct periods 1 dsfcn increased from 1617 to 1650 then 2 decreased from 1650 to 1675 3 remained unchanged from 1675 to 1755 4 increased again from 1755 to 1860 5 remained unchanged from 1860 to 1925 and finally 6 decreased rapidly from 1925 to 1995 we propose the following causal chain to explain the observed relationship between dsfcn and sst as tropical pacific ocean sst increases the siberian high weakens and the eastern asian trough strengthens as the air pressure difference weakens the east asian winter monsoon weakens and strong wind frequency decreases causing dsfcn to decrease as well the statistical results support this interpretation of the causal chain

sr nd isotope evidence for modern aeolian dust sources in mountain glaciers of western china in order to apportion the dust sources of mountain glaciers in western china the sr nd isotopic compositions of insoluble particles were determined in snow samples collected from 13 sites the combined plot of 87 sr 86 sr and

karst development and the distribution of karst drainage systems in dejiang guizhou province china abstract the nature of karstification of two contrasting areas on the north guizhou plateau south china is shown to be controlled by structure lithology geomorphic history and tectonics and causes significant differences to arise in the subsurface drainage systems of the areas the shaqi area lies in a syncline of permo triassic limestones underlain by an insoluble sandy shale which forms the local base level karst landforms are strongly influenced by the presence of four erosion levels corresponding to four periods of rejuvenation of the drainage systems drainage is concentrated along the syncline axis and one system naoshuiyan has been pirating another lengshuiyan by headward retreat cave passages are typically phreatic the dejiang town area lies in an anticline of cambrian dolomite and ordovician limestone three large subsurface drainage systems have developed along parallel faults and have typically vadose cross sections

effects of land use land cover and rainfall regimes on the surface runoff and soil loss on karst slopes in southwest china abstract surface runoff and soil loss from 2007 to 2010 related to land use and rainfall regimes in karst hill slopes in guizhou province southwest china were analyzed using the hierarchical clustering method sixty one rainfall events under the subtropical monsoon climate condition were classified into 5 types of rainfall regimes according to the depth maximum 30 min intensity and duration of rainfall in our study we first demonstrated that the amounts of surface runoff and soil loss on the karst hill slopes were very small compared to the non karst areas because the dual hydrological structure in the karst region including ground and underground drainage systems could influence the processes of rainfall recharge and runoff generation most rainfall water was transported underground through limestone fissures and fractures while little was in the form of surface runoff second the runoff and soil loss were affected by land use management and vegetation cover soil loss was intensified in a descending order to five types of land uses pastureland burned area cropland combination vegetation land young forestland third the runoff and soil loss exhibited remarkable variances among different rainfall regimes large runoff and soil loss were mainly created by heavy rainfall storms with a rainfall depth of more than 40 mm and a maximum 30 min rainfall intensity of over 30 mm h 1 in addition rainfall storms with large antecedent precipitations could also produce large runoff and soil loss these observations indicated that limestone fissures and fractures play important roles in surface runoff generation on karst limestone slopes due to their large storage capacity and high infiltration rate lastly the soil erosion risk in the karst pure limestone slope is quite high and should be paid particular attention especially in regards to over grazing because the soil loss created by a single heavy rainstorm in pastureland was 5 times the annual soil loss tolerance

effect of catchment properties on runoff coefficient in a karst area of southwest china frequent human activities and climate change in the karst region of southwest china since the 1950s have led to the investigation of response of runoff to climate and catchment properties runoff coefficient rc as an expression variable of the catchment response to rainfall is important to describe runoff dynamics and to estimate available streamflow for utilization in this study the equations of rc associated with its attributors of climate condition and catchment property were derived using the budyko framework the equations were used to estimate relationship between the rc and the attributors in the karst catchments in guizhou province of southwest china analysis in the selected 23 karst catchments demonstrates that the spatial distribution of rc is dominated by the catchment properties such as the catchment properties of geology slope and land use and land cover rather than climate condition of drought index correlation analysis indicates that the catchment with a large slope usually has a high value of rc and a large proportion of carbonate rock in a catchment reduces rc in the study area temporal increasing trend of rc during 1961 2000 was found for most catchments in the study area this increasing trend was primarily resulted from changes of catchment properties e g deforestation in large areas of guizhou province during the 1950s 1980s copyright 2013 john wiley sons ltd

landslide susceptibility assessment in the izmir west anatolia turkey city center and its near vicinity by the logistic regression method a landslide susceptibility assessment for izmir city western turkey which is the third biggest city of turkey was performed by a logistic regression method a database of landslide characteristics was prepared using detailed field surveys the major landslides in the study area are generally observed in the field dominated by weathered volcanics and 39 63 of the total landslide area is in this unit the parameters of lithology slope gradient slope aspect distance to drainage distance to roads and distance to fault lines were used as variables in the logistic regression analysis the effect of each parameter on landslide occurrence was assessed from the corresponding coefficients that appear in the logistic regression function on the basis of the obtained coefficients lithology plays the most important role in determining landslide occurrence and distribution slope gradient has a more significant effect than the other geomorphological parameters such as slope aspect and distance to drainage using a predicted map of probability the study area was classified into five categories of landslide susceptibility very low low moderate high and very high whereas 49 65 of the total study area has very low susceptibility very high susceptibility zones make up 11 69 of the area

the influence of geomorphological position and vegetation cover on the erosional and hydrological processes on a mediterranean hillslope soil erosion and runoff rates are assumed to be highly dependent on slope position however little knowledge exists about the hydrogeomorphological processes at the pedon scale that support this idea in order to assess the hydrological and erosional behaviour of soils at different slope positions simulated rainfall experiments 55 mm was applied during one hour were carried out on a south facing slope with underlying limestone in south east spain in the mean terms the erosion rates 9 g m2 hr 1 and the runoff coefficients 12 were very low at the scale of measurement 0 25 m2 the slope position does not affect erosion rates when the measurements are carried out under extreme dry conditions during summer the low runoff rates found in summer under thunderstorms of high intensity 5 year return period and the runon into surfaces with higher infiltration rates resulted in no detectable direct surface runoff hortonian at the slope scale this implies that erosion as a consequence of surface overland flow will only take place during events of high magnitude 55 mm hr 1 and low frequency 5 years vegetation is the most important factor determining the soil erosion and runoff rates within the slope 1998 john wiley sons ltd

twentieth century warming preserved in a geladaindong mountain ice core central tibetan plateau high resolution 18 o records from a geladaindong mountain ice core spanning the period 1477 1982 were used to investigate past temperature variations in the yangtze river source region of the central tibetan plateau tp annual ice core 18 o records were positively correlated with temperature data from nearby meteorological stations suggesting that the 18 o record represented the air temperature in the region a generally increasing temperature trend over the past 500 years was identified with amplified warming during the 20th century a colder stage spanning before the 1850s was found to represent the little ice age with colder periods occurring during the 1470s 1500s 1580s 1660s 1700s 20s and 1770s 1840s compared with other temperature records from the tp and the northern hemisphere the geladaindong ice core record suggested that the regional climate of the central tp experienced a stronger warming trend during the 20th century than other regions in addition a positive relationship between the geladaindong 18 o values and the north atlantic oscillation index combined with a wavelet analysis of 18 o records indicated that there was a potential atmospheric teleconnection between the north atlantic and the central tp

a 108 83 m ice core record of atmospheric dust deposition at mt qomolangma everest central himalaya abstract the central himalaya can be regarded as an ideal site for developing a long term ice core dust record to reflect the environmental signals from regional to semi hemispheric scales here we present a dust record from segments of a 108 83 m ice core recovered from the east rongbuk er glacier 27 59 n 86 55 e 6518 m a s l on the northeast slope of mt qomolangma everest in the central himalaya covering the period ad 600 1960 due to rapidly layer thinning and coarse sampling we primarily discuss the changes in the dust record since ad 1500 in this paper results show a significant positive relationship between the dust concentration and reconstructed air temperatures during this period suggesting a likely cold humid and warm dry climatic pattern in the dust source regions namely central asia this is associated with the variability in the strength of the westerlies and its corresponding precipitation

high resolution atmospheric cadmium record for ad 1776 2004 in a high altitude ice core from the eastern tien shan central asia two ice cores drilled to the bottom were recovered from miaoergou flat topped glacier 43 03 19 n 94 19 21 e 4512 ma s l eastern tien shan central asia in 2005 a high resolution record of cadmium was established by applying inductively coupled plasma mass spectrometry to one of the ice cores 57 6 m covering a 228 year period from ad 1776 to 2004 the results showed long term variations of atmospheric transport and deposition of cadmium at high altitudes trend analysis based on the sequential mann kendall test and the analysis of crustal enrichment factors of the cadmium shows that natural contribution mainly from rock and mineral dust dominated the atmospheric cycles of cadmium during the period ad 1776 1957 which was confirmed by the significant correlation between the winter north atlantic oscillation nao index and annual cadmium concentration the concentration of cadmium increased sharply from ad 1957 to 2004 suggesting increasing influence from human activities such as metals production the ice core record indicated increasing atmospheric cadmium pollution in response to rapid economic growth after ad 1957 in the region

high resolution trace element records of an ice core from the eastern tien shan central asia since 1953 ad 1 high resolution records of trace elements ba v cr mn co ni cu as rb sr mo cd sn sb tl pb bi th and u quantified in an ice core recovered from the miaoergou glacier in the eastern tien shan central asia spanning the period 1953 2004 ad provide the first comprehensive time series on characterizing the relative contributions from natural and anthropogenic sources to the deposition of trace elements in central asia it is suggested that rock and soil dust is the most important natural source for most of elements investigated slight decreases in concentrations or fallout fluxes of crustal elements such as ba mn rb th u and sr are observed during recent decades which may be due to decreases in dust emissions from source regions and a decrease of accumulation rate since 1980s the increasing trends of median concentrations and crustal enrichment factors efc of v cr co ni cu and mo during the period 1953 2004 ad are insignificant in comparison to their respective levels prior to 1953 ad however slight enhancements of both concentrations and efc are observed for cd sb pb bi tl and sn since 1950s such recent increases are likely to be attributed to enhanced anthropogenic emissions such as metal smelting mining stationary fossil fuel combustion and combustion of gasoline due to human activities in eurasia particularly xinjiang in northwestern china russia and kazakhstan our study supports evidence that environmental contamination has become a global problem for pb and bi and a large scale phenomenon for cd sb tl and sn

abandoned stone quarries in and around the izmir city centre and their geo environmental impacts turkey there are 70 abandoned quarries in and around izmir city centre of these quarries 56 are in andesites 2 are in dasitic lavas 4 are in flysch and 8 are in limestones the quarries initially located near the izmir city centre are now within the city centre because of the expansion of the urbanization due to the rapid increase of population geo environmental problems identified in the abandoned quarry sites are slope stability problems such as sliding and toppling geotechnical study of the abandoned stone quarries in and around the city centre of izmir which has been carried out involves the recording and determining the properties of discontinuities for stability assessment of already failed and standing slopes in the quarries using stereographic projection techniques and the statistical evaluation of different types of rock mass movements in these quarries the number of mass movements that had already occurred and are likely to occur in 70 quarries lying in and near izmir have been determined as 84 totally stability analyses of rock slopes have shown that rock falls toppling plane and wedge failure type rock mass movements are more common in the south of izmir bay but toppling type slope failures are more frequent in the north

runoff generation sediment movement and soil water behaviour on calcareous limestone slopes of some mediterranean environments in southeast spain abstract an interpretation of soil hydrology and erosion data obtained from limestone areas in southeast spain is presented in the framework of recent hypotheses on runoff generation mechanisms in mediterranean environments the main objective is to synthesise and harmonise the data in theoretical concepts or behavioural models of hydrological functioning of mediterranean limestone slopes for this purpose data were collected in a typical limestone area with climatic characteristics ranging from subhumid to semiarid several sites were chosen with comparable slopes vegetation and soils along a transect of 20 km to carry out several research projects the data discussed in this paper consist of information on water redistribution within the soil profiles obtained from long duration up to 5 h rainfall simulation experiments with continuous monitoring of soil moisture at different depths runoff and sediment concentration data were obtained i from rainfall simulation experiments with different antecedent soil moisture conditions and ii as natural results from open gerlach plots on runoff and sediment movement over 4 years three conceptual models of water redistribution during the infiltration process could be observed two of them imply nonuniform water redistribution within the soil profile due mainly to macropore flow caused by specific soil surface characteristics at the plot scale runoff generated in bare patches is mainly hortonian in plots with previously wetted soils or soils with high infiltration capacities the generated runoff implies the saturation of the upper soil both types of runoff are discontinuous through time and space the runoff generation mechanisms at the slope scale have been synthesised into two conceptual models a hortonian discontinuous runoff model that takes place in the most degraded slopes or during high intensity rain events and a mixed runoff generation model in less degraded slopes or in previously wet soils where infiltration excess runoff as well as saturation excess runoff can happen on the same slope in both cases slopes behave as a patchwork of runoff and runon areas the size of the runoff or runon patches is dependent on the climatological conditions these control the hydrological disconnection between different parts of the slopes hortonian and saturation runoff can both be generated and infiltrated downslope

controls of infiltration runoff processes in mediterranean karst rangelands in se spain semiarid karst landscapes represent an important ecosystem surrounding the mediterranean basin for which little is known on runoff generation knowledge of the sources and patterns of variation in infiltration runoff processes and their controls is important for understanding and modelling the hydrological functions of such ecosystems the objectives of this paper are to determine the infiltration rates and their controls in a representative mountain karst area sierra de gador se spain at micro plots and to investigate the integrated response of rainfall on a typical hillslope rainfall simulations in micro plots and natural rainfall runoff monitoring on a hillslope were carried out complementarily we investigated the role of soil surface components vegetation rock outcrop fracture and soil crust topographic position antecedent soil moisture and rainfall characteristics in regulating infiltration runoff processes results of rainfall simulation revealed the importance of vegetation cover and the presence of rock fractures in promoting the infiltration in the limestone karst landscape while bare patches and rock outcrops acted as sources for runoff all plots with 50 vegetation cover had no runoff with up to 55mmh 1 of simulated rain in contrast nearly all bare plots had runoff under the same simulated rain with runoff coefficients ranging from 3 1 to 20 6 on dry soil surface conditions and from 2 0 to 65 4 on wet soil surfaces runoff coefficients amounted to 59 0 79 5 for rock outcrops without cracks but were drastically reduced by the presence of cracks the surfaces with rock fragments resting on the soil generally located in the middle of the slopes prevented more effectively the runoff generation than those surfaces where rock fragments were embedded in the top soil antecedent soil moisture had significant impact on runoff generation with wet soil having doubled runoff coefficient shortened time to runoff and increased runoff rate compared to the same but dry soil linear regressions indicated that the main controls for constant infiltration rate were the cover percentages of vegetation and litter plus rainfall intensity while the major controls for runoff coefficient were the bare soil and vegetation coverage plus rainfall intensity high infiltration rates measured at the micro plots agreed with low intra event runoff coefficients mostly below 1 observed under natural rainfalls at the hillslope runoff depth and coefficient at the hillslope was significantly correlated with rainfall depth maximum hourly rainfall intensity and antecedent precipitation over 20days ap20 during the 1 5 year monitoring period from sep 2003 to mar 2005 the overall infiltration was 41 of the total rainfall amount and the maximum infiltration rate was almost 94 of the largest single rainfall event the results from this study contribute to improved understanding of the magnitude and controls of the surface runoff in semiarid karst mountain areas 2011 elsevier b v