Contribution of biophysical and climate variables to the spatial distribution of wildfires in Iran

This study investigated the relationship between climate and biophysical variables in burned areas in Iran.The fire burned area(FBA)product(Fire CCI 5.1.1),land surface temperature(MOD11C3C),vegetation index(MOD13A1),and climate variables such as temperature,wind speed,relative humidity,and volumetric soil moisture from the ERA5 reanalysis dataset were used.Pearson correlation coefficient was used to determine the relationship between biophysical and climate variables and fire occurrence.The results show that FBA increased by 1.7 hectares/decade from 2001 to 2020.The high FBA in 2010(the black summer of Iran)was due to high temperatures and significant heatwaves that led to extensive wildfires.Although anthropogenic activities are considered a significant cause of wildfires,several variables,including increased temperatures,less precipitation,relative humidity,and wind speed and direction,contribute to the extent and occurrence of wildfires.The country’s FBA hotspot is in the Arasbaran region during the summer season.Temperature and relative humidity are the most significant variables influencing the occurrence of wildfires.The results show the vulnerability of Iran s forests and their high potential for fires.Considering the frequency of fire occurrences in Iran and the limited equipment,fire prevention plans should be carried out by applying proper management in high-risk regions.

Mangrove forests as a nature-based solution for coastal flood protection:Biophysical and ecological considerations

Nature-based coastal protection is increasingly recognised as a potentially sustainable and cost-effective solution to reduce coastal flood risk.It uses coastal ecosystems such as mangrove forests to create resilient designs for coastal flood protection.However,to use mangroves effectively as a nature-based measure for flood risk reduction,we must understand the biophysical processes that govern risk reduction capacity through mangrove ecosystem size and structure.In this perspective,we evaluate the current state of knowledge on local physical drivers and ecological processes that determine mangrove functioning as part of a nature-based flood defence.We show that the forest properties that comprise coastal flood protection are well-known,but models cannot yet pinpoint how spatial heterogeneity of the forest structure affects the capacity for wave or surge attenuation.Overall,there is relatively good understanding of the ecological processes that drive forest structure and size,but there is a lack of knowledge on how daily bed-level dynamics link to long-term biogeomorphic forest dynamics,and on the role of combined stressors influencing forest retreat.Integrating simulation models of forest structure under changing physical(e.g.due to sea-level change)and ecological drivers with hydrodynamic attenuation models will allow for better projections of long-term natural coastal protection.

Assessment of sediment connectivity using modelling and field-based approaches in the Slavíč River catchment(MoravskoslezskéBeskydy Mts,Czech Republic)

Mountain streams act as conveyors of sediments within the river continuum,where the physical transport of sediments between river reaches through the catchment or between individual parts(e.g.,between hillslopes and channels)of the catchment is assumed.This study focused on sediment connectivity analysis in the SlavíčRiver catchment in the MoravskoslezskéBeskydy Mts in the eastern part of the Czech Republic.The connectivity index and connectivity index target modelling were combined with an analysis of anthropogenic interventions.Additionally,field mapping,grain size of bed sediments and stream power analysis were used to obtain information about connectivity in the catchment.Based on the analysis and obtained results,terrain topography is the current main driving factor affecting the connectivity of sediment movement in the SlavíčRiver catchment.However,the modelling provided valuable information about high sediment connectivity despite different recent land use conditions(highly forested area of the catchment)than those in historical times from the 16th to 19th centuries when the SlavíčRiver catchment was highly deforested and sediment connectivity was probably higher.The analysis of anthropogenic interventions,field mapping,grain size of bed sediments and stream power analysis revealed more deceleration of sediment movement through the catchment,decreased sediment connectivity with bed erosion,and gradual river channel process transformation in some reaches.Field mapping has identified various natural formations and human-induced changes impacting the longitudinal and lateral connectivity in the SlavíčRiver.For instance,embankments along 48%of the river's length,both on the right and left banks,significantly hinder lateral sediment supply to the channel.Stream power index analysis indicates increased energy levels in the flowing water in the river's upper reaches(up to 404.8 W m^(-2)).This high energy is also observed in certain downstream sections(up to 337.6 W m^(-2)),where it is influenced by human activities.These conditions lead to intensified erosion processes,playing a crucial role in sediment connectivity.Similar observations were described in recent studies that pointed out the long-term human interventions on many streams draining European mountains,where a decrease in sediment connectivity in these streams is linked with sediment deficits and the transformation of processes forming channels.

Quantifying freeze-melt dynamics of lakes on the Tibetan Plateau using Sentinel-1 synthetic aperture radar imagery

The ice phenology of alpine lakes on the Tibetan Plateau(TP)is a rapid and direct responder to climate changes,and the variations in lake ice exhibit high temporal frequency characteristics.MODIS and passive microwave data are widely used to monitor lake ice changes with high temporal resolution.However,the low spatial resolutions make it difficult to effectively quantify the freeze-melt dynamics of lakes.This work used Sentinel-1 synthetic aperture radar(SAR)data to derive high-resolution ice maps(about 6 days),then with the aid of Sentinel-2 optical images to quantify freeze-melt processes in three typical lakes on the TP(e.g.Selin Co,Ayakekumu Lake,and Nam Co).The results showed that three lakes had an average annual ice period of 125-157 days and a complete ice cover period of 72-115 days,from 2018 to 2022.They exhibit different ice phenology patterns.Nam Co is characterized by repeated episodes of freezing,melting,and refreezing,resulting in a prolonged freeze-up period.Meanwhile,the break-up period of Nam Co lasts for a longer duration(about 19 days),and the break-up exhibits a smooth process.Similarly,Ayakekumu Lake showed more significant inter-annual fluctuations in the freeze-up period,with deviations of up to 28 days observed among different years.Compared to the other two lakes,Selin Co experienced a relatively short freeze-up and break-up period.In short,Sentinel-1 SAR data can effectively monitor the weekly and seasonal variations in lake ice on the TP.Particularly,this data facilitates quantification of the freeze-melt dynamics.

Measuring urban thermal environment from accessibility-based perspective:A case study in a populous city

Understanding the spatial interaction among residents,cooling service,and heat risk area in complex urban areas is conducive to developing targeted management.However,traditional urban thermal environment assessments typically relied on simple linear integration of associated indicators,often neglecting the spatial interaction effect.To explore the spatial interaction among the three elements,this study proposes an accessibility-based urban thermal environment assessment framework.Using Zhengzhou,a rapidly urbanizing city,as an example,remotely sensed images from three periods(2010,2015 and 2020)were applied to extract urban green space(UGS)and hot island area(HIA).An improved two-step floating catchment area(2SFCA)method and bivariate local Moran’s I were employed to explore whether residents’clustering locations are more likely to access cooling service or to be exposed to heat risk.The results demonstrate that the UGS in the city has been expanding,whereas the HIA shrank within the inner city in 2015 and then increased in 2020.Even though the urban thermal environment may have improved in the last decade,the spatial interaction among the residents,cooling service and heat risk area could be exacerbated.Spatial autocorrelation shows an increase in locations that are disadvantageous for resident congregation.Even when sufficient cooling services were provided,residents in these areas could still be exposed to high heat risk.The developed urban thermal environment framework provides a novel insight into the residents’heat risk exposure and cooling service accessibility,and the findings could assist urban planners in targeting the improvement of extra heat exposure risk locations.

Exploring the Forest Cover Changes and Influential Factors of Dongsithouane National Production Forest Area, Savannakhet Province, Lao PDR

The Dongsithouane National Production Forest (DNPF) is one of the largest natural forest areas in Savannakhet, Lao PDR, which has been a vital support for the local community’s livelihood, Recently, significant changes in land use and land cover (LULC) have been observed in this area, leading to a reduction of natural forests. There were two separate methods of this study: firstly, to identify LULC changes across three different periods, spectral imagery from the Landsat 5 Thematic Mapper (TM) for the years 2001 and 2011, and the Landsat 8 Operational Land Imager (OLI) for 2021 were used as the primary data sources. The satellite images were preprocessed for various forest classes, including pretreatment of the top of atmosphere reflectance by using QGIS software’s semi-automatic classification plug-in (SCP), and ArcGIS was used for post-classification. A supervised classification approach was applied to the satellite images from 2001, 2011, and 2021 to generate diverse maps of LULC. Secondly, a household survey dataset was used to investigate influential factors. Approximately 220 households were interviewed in order to collect socio-economic information (including data on population growth, increased business activities, location of the area, agriculture land expansion, and need for settlement land). Household survey data was analyzed by using SPSS. Descriptive statistics, including frequency distributions and percentages, were applied to observe characteristics. Additionally, a binary logistic regression model was used to analyze the socioeconomic factors related to LULC change in DNPF. Key findings indicated a decline in natural forest areas within the study site. Specifically, both dry dipterocarp forest (−11.35%) and mixed deciduous forest (−0.18%) decreased from 2001 to 2021. The overall accuracy of the LULC maps was 94%, 86%, and 89% for the years 2001, 2011, and 2021 respectively. In contrast, agricultural land increased significantly by 155.70%, while built-up land, and water bodies increased by 65.54% and 35.33%, respectively. The results also highlighted a significant increase in construction land, up to 65.54%. Furthermore, the study found a correlation between agricultural expansion and a reduction of forest areas, along with an increase in built-up land along the forest areas’ boundaries. Timber exploitation and charcoal production also contributed to the decline in forest cover. The logistic regression model identified significant determinants of LULC change, including the area’s location, agricultural land expansion, increased business activity, and the need for settlement land. These factors have influenced the management of DNPF. Urgent sustainable management practices and actions, including forest ecosystem protection, village agricultural zoning, water source and watershed protection and public awareness, are required to preserve the forest areas of DNPF.

黄土古气候变化趋势与青藏高原隆升关系初探

粒度和磁化率是两个研究黄土古气候最常用的古环境变化指示参数,它们随着黄上占土壤地层变化而出现峰和谷的对应已经被证明是反映了天文轨道要素的周期变化。文章试图忽略这些受控于轨道要素的气候周期变化,而主要侧重考察黄土地层这两个参数的平均值(或背景值)所反映的长期变化趋势。对兰州九州台黄土进行了系统采样和测量,发现兰州九州台黄土剖面粒度和磁化率曲线显示出两个明显的趋势,粒度从剖面底部向上有明显逐渐变粗趋势,指示着冬季风增强,与此同时,磁化率自下而上却逐渐增大,指示着夏季风增强的趋势。与黄土高原其他黄土剖面磁化率和粒度曲线对比发现,这是两个普遍存在的趋势。地理位置靠近青藏高原的剖面,这两个增大的趋势更明显。冬、夏季风同时逐渐增强是海陆热力差异增大所引起,反映了青藏高原第四纪时期的逐渐不断的隆升过程。因此,根据粒度和磁化率曲线变化趋势线的变化特点可以帮助分析和反推第四纪以来青藏高原隆升的过程。兰州九州台以及黄土高原各剖面粒度和磁化率曲线的线性变化趋势则可能指示着第四纪以来青藏高原是逐渐均匀缓慢的变化过程。我们对22Ma以来风积地层记录的变化趋势也做了分析。前人过去普遍认识的第四纪以来跳跃式或间歇式剧烈隆升在我们的数据中没有得到反映。黄土高原西部西宁、兰州、靖远等剖面磁化率显著的增长趋势可能与青藏高原隆升到一定高度后高原季风加强所致。

水稳定同位素示踪的冰川流域水文模拟及不确定性研究——以乌鲁木齐河源1号冰川为例

水文模拟不确定性长期以来是制约寒区水文发展的瓶颈问题。水稳定同位素示踪为认识冰川流域径流过程提供了重要“指纹”信息,但仍缺乏有效模型将该信息与冰川水文模型耦合,而且同位素信息对冰川流域水文模型不确定性的约束效果也有待检验。将水稳定同位素信息(δ^(18)O)与冰川流域水文模型FLEXG相耦合,实现对冰川流域水稳定同位素和径流过程的耦合建模(FLEXG-iso),并在乌鲁木齐河源1号冰川流域进行模拟检验和径流分割。结果表明:模型不仅对2013—2016年径流过程有良好的模拟效果,还可以重现水稳定同位素、冰川物质平衡等重要过程。利用水稳定同位素这一辅助数据,提高了模型参数的识别能力,减少了模拟过程中各水源的相互妥协效应和不确定性范围。2013—2016年1号冰川断面径流32%~34%来自融雪,48%~51%来自融冰,0%~7%来自地下水,12%~15%来自降雨径流。水稳定同位素对雪和冰川相关中间过程有明显的约束能力,原有模型对融冰贡献的模拟偏高约7%。FLEXG-iso模型的建立有助于推动寒区水文学理论和方法的发展,以及寒区水资源、生态环境保护等相关决策制定。

GIS-based landslide susceptibility mapping using numerical risk factor bivariate model and its ensemble with linear multivariate regression and boosted regression tree algorithms

In this study, a novel approach of the landslide numerical risk factor(LNRF) bivariate model was used in ensemble with linear multivariate regression(LMR) and boosted regression tree(BRT) models, coupled with radar remote sensing data and geographic information system(GIS), for landslide susceptibility mapping(LSM) in the Gorganroud watershed, Iran. Fifteen topographic, hydrological, geological and environmental conditioning factors and a landslide inventory(70%, or 298 landslides) were used in mapping. Phased array-type L-band synthetic aperture radar data were used to extract topographic parameters. Coefficients of tolerance and variance inflation factor were used to determine the coherence among conditioning factors. Data for the landslide inventory map were obtained from various resources, such as Iranian Landslide Working Party(ILWP), Forestry, Rangeland and Watershed Organisation(FRWO), extensive field surveys, interpretation of aerial photos and satellite images, and radar data. Of the total data, 30% were used to validate LSMs, using area under the curve(AUC), frequency ratio(FR) and seed cell area index(SCAI).Normalised difference vegetation index, land use/land cover and slope degree in BRT model elevation, rainfall and distance from stream were found to be important factors and were given the highest weightage in modelling. Validation results using AUC showed that the ensemble LNRF-BRT and LNRFLMR models(AUC = 0.912(91.2%) and 0.907(90.7%), respectively) had high predictive accuracy than the LNRF model alone(AUC = 0.855(85.5%)). The FR and SCAI analyses showed that all models divided the parameter classes with high precision. Overall, our novel approach of combining multivariate and machine learning methods with bivariate models, radar remote sensing data and GIS proved to be a powerful tool for landslide susceptibility mapping.

Impact of normal stress-induced closure on laboratory-scale solute transport in a natural rock fracture

The impact of normal stress-induced closure on fluid flow and solute transport in a single rock fracture is demonstrated in this study.The fracture is created from a measured surface of a granite rock sample.The Bandis model is used to calculate the fracture closure due to normal stress,and the fluid flow is simulated by solving the Reynold equation.The Lagrangian particle tracking method is applied to modeling the advective transport in the fracture.The results show that the normal stress significantly affects fluid flow and solute transport in rock fractures.It causes fracture closure and creates asperity contact areas,which significantly reduces the effective hydraulic aperture and enhances flow channeling.Consequently,the reduced aperture and enhanced channeling affect travel time distributions.In particular,the enhanced channeling results in enhanced first arriving and tailing behaviors for solute transport.The fracture normal stiffness correlates linearly with the 5th and 95th percentiles of the normalized travel time.The finding from this study may help to better understand the stress-dependent solute transport processes in natural rock fractures.

Global chronostratigraphical correlation table for the last 2.7 million years

The table provides a correlation of chronostratigraphical subdivisions of late Cenozoic geological time, spanning the last 2. 7 million years. The formal division of the Quaternary is the responsibility of the International Commission on Stratigraphy＇s （ICS） Subcommission on Quaternary Stratigraphy （SQS）, in partnership with the International Union for Quaternary Research＇s （INQUA） Commission on Stratigraphy and Chronology （SACCOM）. This is the third published version of the chart. Earlier versions are Gibbard et al., 2004, 2005. See http：//www.quaternary.stratigraphy.org.uk/correlation/ for history.

Evidence of the formation of landslide-dammed lakes in the Zagros Mountains range,Iran

Alternation of high and low resistance sedimentary beds,active tectonics,large rivers,and slope erosion in valleys consequently resulted in landslide in dammed lakes within the Zagros range.This study presents the results in the analysis of geological and topographic data,satellite imageries,morphotectonics and hydrodynamics of drainage networks about the landslide dammed lakes.There are four landslides in central Zagros(Zagros FoldThrust Belt,ZFTB)which have formed five dammed lakes named,Seymareh,Jaidar,Shur,Shimbar,and Godar.According to the results,damming landslides occurred in the active-tectonic regions on the slopes of anticlines and in valleys with undercutting effects of rivers on their slopes consisting of alternations of loose and resistant beds.The studied landslide dams in narrow valleys are formed as a result of blocking river by sliding debris slopes and rock slides.This study also indicates the formation of Jaidar and Godar in one stage and the presence of Lake Terrace sequence in Seymareh,Shur and Shimbar lakes.The observed sequences of terrace formation in these lakes are caused by four Seymareh Landslides followed by the three-stage excavation of Shur andShimbar lakes.

The Impact of Topography on Social Factors,a Case Study of Montenegro

Relationships between environmental and social factors have long been studied by geographers.Nowadays,GIS-aided statistical analysis provides new tools to explore these relationships.In order to detect the impact of topography on social factors,we selected the country of Montenegro as a case example due to its high topographic variability.We compared the spatial pattern of population,settlements and ethnic minorities to physical geographic factors,especially to topography,but lithology and land cover data were also taken into consideration.We found that certain factors are closely correlated,e.g.the settlement density linearly decreases with elevation,while the characteristic settlement area shows an exponential increase upwards.The population density is not related to absolute elevation,but it is in close correlation with height(i.e.elevation relative to the local minimum).Population change and illiteracy are also topography-related social factors.On the contrary,the variable ethnic pattern of Montenegro is influenced by historical,political and economic effects rather than by environmental factors or topographic features.As a conclusion we state that in the scale of a country or a region,the environment can strongly impact some social factors.

A soil quality index for evaluation of degradation under land use and soil erosion categories in a small mountainous catchment, Iran

Soil erosion and land use type have long been viewed as being particularly important drivers of soil degradation.The objectives of this study,therefore,were to select a new soil quality index(SQI)which varies significantly with land use/soil erosion,and to evaluate the new SQI using expert opinion.In total,18 soil physical,chemical,and biochemical properties(indicators)were measured on 56 soil samples collected from four land use/soil erosion categories(rangeland/surface erosion,rangeland/subsurface erosion,cultivated land/surface erosion and dry-farming land/surface erosion).Principal component and classification analysis(PCCA)identified five PCs that explained 77.7%of the variation in soil properties with the biochemical PC varying significantly with land use/soil erosion.General discriminant analysis(GDA)selected urease and clay as the most sensitive properties distinguishing the land use/soil erosion categories.The GDA canonical scores for the new SQI were significantly correlated with expert opinion soil surface summed scores(for soil movement,surface litter,pedestalling,rills and flow pattern)derived using the U.S.Department of the Interior Bureau of Land Management(BLM)method.A forward stepwise general regression model revealed that the new SQI values were explained by soil movement,surface litter,and the summed values of the soil surface factors.Overall,this study confirmed that soil quality in the study area in Iran is controlled by land use and corresponding soil erosion.

Changing human-environment interactions in medium mountains:the Apuseni Mts(Romania)as a case study

The study of human-environment relationships in mountain areas is important for both theoretical and practical reasons, as many mountain areas suffer similar problems, such as depopulation, unemployment and natural hazards. Medium mountains constitute a special case within mountains, because they are more populated but less attractive as tourist destinations than high mountains. In this context, the Apuseni Mts （Romania） are considered as a ease study. In this paper, we apply GIS-based, quantitative methods to characterize the strength and dynamics of human-environment interactions, taking into consideration some environmental factors （elevation, relative height, slope, river distance, lithology, land cover, natural attractions） as well as historical population and recent tourism data. We found that population density has strong （r2〉0.8） relationships with all relief factors （elevation, relative height, slope, river distance）, and that best-fit functions are nonlinear. We outlined the varying demographic scenarios by elevation zones and interpreted the historically switching sign of population change versus elevation relationship. We demonstrated that lithology also has an impact on the spatial distribution of population, although it is not independent from the relief effect. The land cover of the mainly cultural landscape is very strongly correlated with relief parameters （especially slope）, which suggests good adaptation. We pointed out the dominance of karst objects in the natural tourism potential of the Apuseni Mts and also explored further components of real tourism （spas, heritage, towns）. Finally, we concluded that the environmental settings investigated do in fact constrain the spatial framework of society, but soeio-economic changes in history can be explained from the side of society, which conforms to the theory of cultural possibilism.

Topographic and lithologic controls behind mountain depopulation in Zlatibor District(Western Serbia)

Mountain depopulation is a worldwide phenomenon observed in all continents. It has varied socio-economic reasons;among others, the low profitability of traditional agriculture, the better job possibilities and the higher level of services in urban settlements. However, it is often recognized that depopulation is related to natural factors such as elevation, slope or lithology. It is also observed that protected areas are frequently established in depopulated mountain regions. Their primary aim is the conservation of nature, but they may help tourism development as well. Tourism, in turn, may slow down or even reverse the process of depopulation. In this study, we investigate the impact of topographic and lithologic factors, namely of karst settings, on mountain demographic processes and the relationship of protected areas and tourism through the example of the northern part of Zlatibor District(Western Serbia). The study area is characterized by mountains and hills at elevations from 200 to 1600 m a.s.l. Our aim is to find GIS-based statistical relationships between topographic, lithologic factors and demographic characteristics. In this area, mountain depopulation started after WWII, and weproved that this process was strongly controlled by topographic factors. The higher and more dissected the area, the more significant is the decrease of the population and the more advanced is the ageing. As a result, population density contrasts are much more pronounced now than 70 years ago. After WWII, depopulation and ageing became gradually more serious on karstic terrains than on non-karst. However, by using compound topographic and lithologic types, we proved that it is not the effect of karst, but the effect of topography. The flow of population from hills and mountains to valleys and basins are closely related to the restructuring of the economic sectors. At present, for the study area, the development of tourism is unequivocally naturebased and connected to protected areas, namely to Tara National Park, Zlatibor Nature Park and ?argan–Mokra Gora Nature Park. In this paper, we also demonstrate how lithology influences tourism possibilities. The leading role of Zlatibor in tourism development is largely thanks to its favourable position on a main transit route.

Soil Properties in Two Soil Profiles from Terraces of the Nam Co Lake in Tibet,China

This article investigates the soil properties in two soil profiles from the terraces of the Nam Co Lake in Tibet,China. Profile 1,with a slope aspect to east,is 37 m,and profile 2,to southwest,is 32 m above the lake level. Twelve and nine layers were identified in profile 1 and profile 2,respectively,based on the color,texture,structure,moisture content,presence of carbonate,and root density. Grain sizes and measurements of water content,total organic carbon,total inorganic carbon,total carbon,pH value and electrical conductivity were all analyzed for each sample. The results show that soil is poorly developed because of sparse vegetation coverage and weak chemical weathering in the cold and arid area. The results also indicate that the soil properties are different between the two profiles and suggest that soil is better developed in profile 1 than in profile 2. These differences are ascribed to the dissimilarity of landform,vegetation and timing. Profile 1 faces to east as compared with profile 2 facing to southwest and gets less insolation and therefore less evaporation. Thus,vegetation grows better in profile 1 than in profile 2. Radiocarbon dating and OSL dating show that profile 1 underwent a longer soil forming process than profile 2,which is helpful for the soil development in profile 1.

Urban green spaces accessibility in two European cities:Vilnius(Lithuania)and Coimbra(Portugal)

Urban green spaces(UGS)are essential for human well-being,contributing towards quality of life and promoting social interactions and inclusion.Accessibility to recreational UGS is key to human well-being in urban areas.However,there is a lack of works focused on recreational UGS accessibility in cities from different countries,using different types of transport.In this work,we studied the accessibility to recreational UGS in Vilnius(Lithuania)and Coimbra(Portugal)through four transport modes(foot,bike,bus and car)within 5-and 10-minute distance.The results showed important differences between cities.Vilnius had higher accessibility to recreational UGS than Coimbra in all transport modes.In both cities,the accessibility was highest by car and lowest by bus.Also,the percentage of population covered by 5-and 10-minute distance UGS accessibility in Vilnius is higher than in Coimbra,despite the lower population density in Vilnius.A large number of recreational UGS,their geographic distribution,the dispersed population pattern,and the location of several urbanizations near recreational UGS increased the inhabitant’s accessibility to recreational UGS in Vilnius.The differences in accessibility between cities were mainly attributed to the large number of recreational UGS and higher road network density,cycleways and footways density,and bus lines in Vilnius,compared to Coimbra.This work identified the areas where recreational UGS accessibility is difficult in using different transport modes and need to be improved in study areas.This is essential to support urban planners and increase cities’well-being.The findings of this work will be important for the management of the studied urban areas.

The Last Glacial-Interglacial Transition

The Last Glacial-Interglacial Transition is one of the most intensively studied periods in Earth History. The rapid climate and environmental changes that occurred during the transition can be used to test ideas about the functioning of our climate system. The stratigraphy of this period has been thoroughly investigated and, in particular, the recently proposed event stratigraphy for the Last Glacial-Interglacial Transition based on the Greenland ice core records serves as a tool for synchronisation of records from the ice, marine and terrestrial environment.

Inland-coastal demographic transformations in a karst area:a case study of the surroundings of Krka National Park(Croatia)

According to geographic possibilism,environment does not determine socio-economic development.However,the environment sets certain constraints and limitations for development.How do natural settings influence population dynamics?In this study,we examine this question using the example of?ibenik-Knin County,which includes Krka National Park(NP)with a GIS-based statistical approach.The following parameters represent natural factors:elevation,slope,distance from water,and proportion of karst areas.In addition,distance from Krka NP was also added as an independent seminatural factor(despite the fact that it is a social construction).The dependent social parameters are population density for selected historical dates,population change,year of maximum population,natural increase,migration,and age index.The analysis units are the 199 settlements found in the county,and the 20 local administrative units(LAU2).The study period can be divided into five phases:from the first census in 1857 to 1921,there was a slow increase in most settlements;then a relatively constant phase up to 1961(some settlements began shrinking in this period);a slow decrease until 1991;arapid decrease during the next decade;and relative stabilisation to present day.These processes were also accompanied by significant inner and outer migrations.As for the relationships between natural and demographic factors,we found that although the coastal-inland area dichotomy is dominant in the study area,elevation has the highest correlation with most population parameters.However,distance from water is also significantly correlated with population change and migration in certain periods.In the inland areas,there are statistically significant differences between the demographic processes of fully-karstic and partially-karstic areas,while in the coastal zone,the karst effect is overshadowed by other social processes.The impact of Krka NP on the demographic characteristics of the surrounding settlements was statistically not detectable.Our final conclusion is that correlations between natural and population parameters are low or moderately strong but statistically significant in many cases,thus the basic principles of geographic possibilism are valid for the area.