scholarly journals Pollen-based paleoclimate reconstructions of Beloslav Lake (Northeastern Bulgaria) during the last 6000 years using modern analog technique (MAT)

2021 ◽  
Vol 82 (3) ◽  
pp. 132-134
Author(s):  
Stoyan Vergiev

The aim of the present study is to reconstruct the palaeoclimate variables in the Beloslav Lake Region (Northeastern Bulgaria) during the last 6000 years, based on the pollen analysis from lacustrine core Bel-1 and using modern analog technique (MAT). Pollen data was used for reconstructions of four parameters: average annual temperature, average temperature of the warm and cold half-year and average annual precipitation.

2020 ◽  
Vol 81 (3) ◽  
pp. 155-157
Author(s):  
Stoyan Vergiev ◽  
Mariana Filipova-Marinova

The aim of the present study is to reconstruct the palaeoclimate variables in North-Eastern Bulgaria during the last 7000 years, based on the pollen analysis from 2 lacustrine cores and using modern analogue technique (MAT). Pollen data were used for the reconstruction of four parameters: the average annual temperature, the average temperature of the warm and cold half-year and the average annual precipitation.


Author(s):  
Horea PĂCURAR ◽  
Marcel DÎRJA ◽  
Ioan PĂCURAR ◽  
Sanda ROȘCA ◽  
Ștefan BILAȘCO ◽  
...  

The aim of this research was to identify the ecological factors which have influences on distribution, development and habitat suitability of the summer truffle (Tuber aestivum) in the Sub-Carpathian region of Transylvania. The ecological factors such as average annual temperature (°C), average annual precipitation (mm/year), the length of the bioactive period (months), land slope (grade), slope orientation, soil pH and its compaction level were analyzed having specific influences on forest vegetation development in Sub-Carpathian hills, and in the same time on the possibility of symbiosis existence between the trees and summer truffle. The most favorable regions from the Sub-Carpathians of Transylvania for summer truffle growth proved to be Dealurile Năsăudului and Homoroadelor Sub-Carpathians followed by Muscelele Năsăudului and hills of Bistrița, where the average annual temperature is between 6,8-11°C with an average annual precipitation of 900 mm/year, a 3-6 months long bioactive period and high humus content of the soil.


Atmosphere ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 592
Author(s):  
Mehdi Aalijahan ◽  
Azra Khosravichenar

The spatial distribution of precipitation is one of the most important climatic variables used in geographic and environmental studies. However, when there is a lack of full coverage of meteorological stations, precipitation estimations are necessary to interpolate precipitation for larger areas. The purpose of this research was to find the best interpolation method for precipitation mapping in the partly densely populated Khorasan Razavi province of northeastern Iran. To achieve this, we compared five methods by applying average precipitation data from 97 rain gauge stations in that province for a period of 20 years (1994–2014): Inverse Distance Weighting, Radial Basis Functions (Completely Regularized Spline, Spline with Tension, Multiquadric, Inverse Multiquadric, Thin Plate Spline), Kriging (Simple, Ordinary, Universal), Co-Kriging (Simple, Ordinary, Universal) with an auxiliary elevation parameter, and non-linear Regression. Root Mean Square Error (RMSE), Mean Absolute Error (MAE), and the Coefficient of Determination (R2) were used to determine the best-performing method of precipitation interpolation. Our study shows that Ordinary Co-Kriging with an auxiliary elevation parameter was the best method for determining the distribution of annual precipitation for this region, showing the highest coefficient of determination of 0.46% between estimated and observed values. Therefore, the application of this method of precipitation mapping would form a mandatory base for regional planning and policy making in the arid to semi-arid Khorasan Razavi province during the future.


2021 ◽  
Vol 7 (5) ◽  
pp. 1113-1122
Author(s):  
Bo Chen ◽  
Shi-jun Xu ◽  
Xin-ping Zhang ◽  
Yi Xie

Using the methods of literature review, regression analysis and moving average, this paper selects the daily precipitation of Changsha and Chengde from 1951 to 1986 as samples, and analyzes the average precipitation, precipitation frequency, precipitation intensity, extreme precipitation time and other indicators of Changsha and Chengde from the perspective of interannual and seasonal changes Trends. The researches show that: the average precipitation of Changsha in the 36 years is 1151.2mm, spring is the wet season, autumn and winter are the dry seasons, and the maximum average precipitation is in spring; the average annual precipitation, precipitation frequency in spring, summer and winter, annual precipitation frequency, annual precipitation intensity and extreme precipitation events show a decreasing trend. The average annual precipitation of Chengde city is 454.1 mm, wet season in summer and dry season in spring, autumn and winter; the average annual precipitation, precipitation in four seasons, annual precipitation frequency, precipitation frequency in spring, autumn and winter, annual precipitation intensity and extreme precipitation events show a decreasing trend, while the precipitation frequency in summer shows an increasing trend. The study of regional climate change based on the time series data of this stage is of great significance to comprehensively understand the law of regional climate change and predict the future trend of climate change.


Author(s):  
V. V. Hrynchak

The decision about writing this article was made after familiarization with the "Brief Climatic Essay of Dnepropetrovsk City (prepared based on observations of 1886 – 1937)" written by the Head of the Dnipropetrovsk Weather Department of the Hydrometeorological Service A. N. Mikhailov. The guide has a very interesting fate: in 1943 it was taken by the Nazis from Dnipropetrovsk and in 1948 it returned from Berlin back to the Ukrainian Hydrometeorological and Environmental Directorate of the USSR, as evidenced by a respective entry on the Essay's second page. Having these invaluable materials and data of long-term weather observations in Dnipro city we decided to analyze climate changes in Dnipropetrovsk region. The article presents two 50-year periods, 1886-1937 and 1961-2015, as examples. Series of observations have a uniform and representative character because they were conducted using the same methodology and results processing. We compared two main characteristics of climate: air temperature and precipitation. The article describes changes of average annual temperature values and absolute temperature values. It specifies the shift of seasons' dates and change of seasons' duration. We studied the changes of annual precipitation and peculiarities of their seasonable distribution. Apart from that peculiarities of monthly rainfall fluctuations and their heterogeneity were specified. Since Dnipro city is located in the center of the region the identified tendencies mainly reflect changes of climatic conditions within the entire Dnipropetrovsk region.


2015 ◽  
Vol 32 (2) ◽  
pp. 91-97
Author(s):  
Eva Břízová ◽  
Małgorzata Roman

Abstract Results of geological and pollen investigations of the lake-bog sediments from the section Wietrzychowice W5, located nearby the Neolithic Funnel Beaker Culture (FBC) megaliths, are presented. The pollen data reveal that sedimentation at Wietrzychowice has begun at the beginning of the Holocene (Preboreal). Pollen analysis was used to determine stratigraphy with regard to sediment characteristics. The pollen spectrum was divided into 8 LPAZes (1-7Xa, 7Xb) which were also, where possible, stratigraphically classified. Radiocarbon dating of 6 730 ± 90 BP (5 730–5 480 BC, MKL-702) at depth of 1.20 m confirmed the pollen analysis age estimation. Five settlement episodes were found in organic sediments in the upper part of the W5 core. The first was presumably during the Preboreal, the second in the early Atlantic, the third in the late Atlantic (probably Neolithic FBC), the fourth in the early Middle Ages and the last one in the late Middle Ages. The pollen analysis was useful to point irregularities in sediment succession. Such a situation made palaeoenvironmental interpretation difficult, but further research is still needed to enable an accurate reconstruction.


2011 ◽  
Vol 137 ◽  
pp. 286-290 ◽  
Author(s):  
Xi Chun ◽  
Mei Jie Zhang ◽  
Mei Ping Liu

The objective of this study is to analyse the climate changing patterns chronologically for exposing the coincident relationships between the lake area fluctuation and the climate change in Qehan lake of Abaga county of Inner Mongolia. The results show that there’s highly interrelation between the changes of the lake area and the climatic factors here, the annual average temperature and annual evaporation are negatively interrelate to the lake area fluctuation, and the annual precipitation interrelate to it is positive. The lake area has descended about 75 km2 during the nearly past 40 years. There were about two considerable lake expansions in 1973, 1998 through the generally lake area descending process.


2018 ◽  
Vol 11 ◽  
pp. 00007
Author(s):  
Maxim V. Bocharnikov ◽  
Anton A. Stas’ko

Bioclimatic substantiation of the vegetation spatial structure of the Kodar-Kalar orobiome on the basis of altitudinal vegetation divisions using the global climate model (BioClim) was carried out. Statistical analysis showed differences between altitudinal belts, sub-belts and also larch forests types on average annual temperature and average annual precipitation. The possibility of using the climate as a factor of differentiation of the vegetation cover at the regional level has been proved.


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