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1

Współczesny cyfrowy Atlas Malej Energetyki Wiatrowej dla Polski (AMEW-PL)

Wieczorek Joanna, Jurasz Jakub, Bochenek Bogdan, Mazur Andrzej, Strzyżewski Tomasz, Figurski Mariusz, Jaczewski Adam, Gruszczyńska Marta

Gaz, Woda i Technika Sanitarna

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2023

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Nr 5

20--26

PL

Zasoby energii promieniowania słonecznego w Polsce są dobrze rozpoznane i w perspektywie długookresowej cechują się stabilnością potencjału w czasie oraz przestrzenni. To przekłada się więc na niewielkie ryzyko inwestycyjne z punktu widzenia estymowanej w przyszłości generacji. Sytuacja jest bardziej skomplikowana w przypadku energetyki wiatrowej. A w szczególności małej energetyki wiatrowej, gdzie warunki wietrzności cechują się znacznym zróżnicowaniem przestrzennym, nawet na niewielkim obszarze, a ponadto dużą zmiennością czasową. Zależną od sytuacji meteorologicznej. Słabe rozeznanie zasobów energii wiatru na wysokości 10-20 metrów nad poziomem gruntu powoduje, iż inwestycja w źródła generacji wiatrowej jest obecnie nadal przedsięwzięciem obarczonym wysokim ryzykiem, ponieważ nie jest możliwe oszacowanie z odpowiednią dokładnością potencjalnej ilości energii elektrycznej jaka może zostać wygenerowana przez generator wiatrowy wybrany przez inwestora. By częściowo zaradzić temu problemowi i wspomóc nowych inwestorów na etapie wyboru lokalizacji inwestycji i szacowania możliwych potencjałów produkcyjnych przedstawiamy koncepcję pierwszego dla obszaru Polski cyfrowego Atlasu malej energetyki wiatrowej, z wyborem treści w formule otwartego dostępu, który dostarczy informacji na temat potencjału energii wiatru na poziomach 10, 30, 50, 80 oraz 100 m n.p.g, z rozdzielczością powierzchniową 1x1 km. Atlas w pierwszej wersji opracowany zostanie na podstawie czterech lat (2019-2022) danych godzinowych pochodzących z modelu INCA-PL 2, a wraz rozwojem szereg czasowy będzie odpowiednio wydłużany. Wykonana analiza wskazuje, na znaczące różnice w potencjale energii wiatru pomiędzy szacunkami w oparciu o model INCA-PL 2 a atlas energetyki wiatrowej prof. Lorenz w szczególności dla rejonu Dolnego Śląska. Dodatkowo wskazujemy, na silny wpływ kształtu krzywej mocy turbiny wiatrowej na wykorzystanie zasob6w energii wiatru w danej lokalizacji wyrażane w kWh generacji w skali roku na 1 kW mocy zainstalowanej.

EN

Poland's solar energy resources are well recognized and in the long term are characterized by a small variability of potential in time and space. This, therefore, translates into a low investment risk from the point of view of estimated future generation. However, this situation is more complicated in the case of wind energy. And specify in the small wind power energy, where wind conditions are characterized by significant spatial variation, even over a small area, in addition to high temporal variability. Dependent on the meteorological situation. Poor understanding of wind energy resources at a height of 10-20 meters above ground level means that investment in wind generation sources is currently still a high-risk venture, as it is not possible to estimate with sufficient accuracy the potential amount of electricity that can be generated by the wind generator chosen by the investor. In order to partially remedy this problem and assist new investors at the stage of investment site selection and estimation of possible production potentials, we present the concept of the first digital Atlas of small wind energy for the area of Poland, with a selection of content in the formula of open access, which will provide information on the potential of wind energy at levels of 10, 30, 50, 80 and 100 meters a.g.l. with a surface resolution of lx1 km. The Atlas in its first version will be developed on the basis of four years (2019-2022) of hourly data from the INCA-PL 2 model, and as it develops, the time series will be extended accordingly. The analysis shows significant differences in wind energy potential between the estimates based on the INCA-PL 2 model and the wind energy atlas of prof. Lorenz in particular for the region of Lower Silesia. In addition, we indicate the strong influence of the shape of the wind turbine power curve on the use of wind energy resources in a given location, expressed in kWh of generation per year per 1 kW of installed power.

2

Sediment yield modeling in Awash Melkasa dam watershed, upper Awash River basin, Ethiopia

Daba Bayisa Itana, Demissie Tamene Adugna, Tufa Fayera Gudu

Acta Geophysica

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2023

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Vol. 71, no. 5

2287--2306

EN

Soil erosion may be a main problem within the Ethiopian highlands. The Awash River basin is one among the Ethiopian highlands suffering from a high rate of surface erosion. Sediment inflow rates of reservoirs and spatial distribution of sediment yield (SY) are required at the sub-basin level to develop alternative watershed management practices. Hence, this study aimed toward estimating SY within the upper Awash River by using the soil and water assessment tool. The spatial, weather, hydrological, reservoir input, and water withdrawal data were collected and analyzed. The model had adjusted and verified for both flow and sediment. The graphical comparison and statistical indicators, coefficient of determination (R2), Nash–Sutcliffe efficiency (NSE), root-mean-square error standard deviation ratio (RSR) and percent bias (PBIAS) had used to evaluate the model's performance. Monthly streamflow and SY estimates were found to be reliable (R2 = 0.78–0.83, NSE = 0.75–0.82, RSR = 0.43–0.5 and PBIAS = 0.1–8.8) based on the model calibration and validation results. After calibration, the simulated average annual SY estimated was 22,109.5 t yr-1at the outlet, with an average spatial distribution of 6.52 t ha-1 yr-1. The model prediction outcomes showed that about 26.16% of the Awash Melkasa watershed, located in southwestern direction, is an erosion-prone area with a mean annual SY ranging from 10 to 18.54 t ha-1 yr-1execiding tolerable soil loss. These sub-basins need prior mitigation measures to reduce soil losses from the catchment.

3

An iterative algorithm for random upper bound kinematical analysis

Chwała Marcin

Studia Geotechnica et Mechanica

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2022

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Vol. 44, nr 1

13--25

EN

A new approach for stochastic upper bound kinematical analyses is described. The study proposes an iterative algorithm that uses the Vanmarcke spatial averaging and kinematical failure mechanisms. The iterative procedure ensures the consistency between failure geometry and covariance matrix, which influences the quality of the results. The proposed algorithm can be applied to bearing capacity evaluation or slope stability problems. The iterative algorithm is used in the study to analyse the three-dimensional undrained bearing capacity of shallow foundations and the bearing capacity of the foundation for two-layered soil, in both cases, the soil strength spatial variability is included. Moreover, the obtained results are compared with those provided by the algorithm, based on the constant covariance matrix. The study shows that both approaches provide similar results for a variety of foundation shapes and scale of fluctuation values. Therefore, the simplified algorithm can be used for purposes that require high computational efficiency and for practical applications. The achieved efficiency using a constant covariance matrix for one realisation of a three-dimensional bearing capacity problem that includes the soil strength spatial variability results in about 0.5 seconds for a standard notebook. The numerical example presented in the study indicates the importance of the iterative algorithm for further development of the failure mechanism application in probabilistic analyses. Moreover, because the iterative algorithm is based on the upper bound theorem, it could be utilised as a reference for other methods for spatially variable soil.

4

Spatial variability study of rainfall in Cartagena de Indias, Colombia

Mouthon-Bello Javier A., Quiñones-Bolaños Edgar, Ortiz-Corrales Jairo E., Mouthon-Barraza Natalia, Hernández-Fuentes Maria D.J., Caraballo-Meza Andrea C.

Journal of Water and Land Development

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2022

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no. 55

138--149

EN

Precipitation is a component of the hydrological cycle, knowing its spatial distribution is vital for the management of hydrographic basins, the territory and the development of fundamental activities for society. That is why the present study shows the spatial variability of rainfall in Cartagena de Indias city with a network of rain gauges, made up of nine pieces of equipment, separated from each other by 0.9-27 km. After a year of recording (2019), using historical series of data, it was found that the maximum rainfall occurs in the trimester between September and November, with interpolated maps made by the Ordinary Kriging (OK) method it was found that the maximum rainfall is focused on the north, centre and west of the territory, instead, the maximum intensities are presented in the centre and west, the minimums for both variables are presented to the east and south. The 70 and 90% of the rain events have a duration of less than 30 min and 1 h, respectively. Three-parameter exponential function was fitted to the paired correlation distances, and presented correlations lower than 0.8, 0.5 and 0.2 from distances of 1, 3 and 7 km, respectively, in 30 min rain integration. It was also found that with a pluviometric network conformed by at least six pieces of equipment and separated by a 5 km distance from each other in the urban area, a correlation of 0.5 and compliance with the WMO recommendations would be obtained.

5

Stress-weighted spatial averaging of random fields in geotechnical risk assessment

Brząkała Włodzimierz

Studia Geotechnica et Mechanica

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2021

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Vol. 43, nr 4

465--478

EN

Effects of spatial fluctuations of soil parameters are considered in a new context – considering variability of soil parameters in conjunction with non-uniform stress fields, which can locally amplify (or suppress) subsoil inhomogeneities. In this way, several design situations for the Coulomb frictional material with random tan(φ(x)) reveal a reduction of variance, which is less significant than for the standard volume averaging. When looking for an 'effective' random variable [tan(φ)]a – that is, a random variable, which is equivalent to the random field tan(φ(x)) – the Vanmarcke averaging by simple volume integrals is insufficient; it systematically overestimates effects of variance reduction, thus causing potentially unsafe situations. The new proposed approach is coherent, formally defined and more realistic.

6

The analysis of spatial variability of precipitation in Poland in the multiyears 1981–2010

Grzywna Antoni, Bochniak Andrzej, Ziernicka-Wojtaszek Agnieszka, Krużel Joanna, Jóźwiakowski Krzysztof, Wałęga Andrzej, Ciupak Agnieszka, Mazur Andrzej, Obroślak Radomir, Serafin Artur

Journal of Water and Land Development

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2020

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no. 46

105--111

EN

The purpose of the paper is to analyze the spatial variability of precipitation in Poland in the years 1981–2010. The average annual rainfall was 607 mm. Precipitation in Poland is characterized by high spatial and temporal variability. The lowest annual precipitation was recorded in the central part of the country, where they equaled 500 mm. The highest annual precipitation totals were determined in the south, equaling 970 mm. The average precipitation in the summer half-year is 382 mm (63% of the annual total). On the basis of data from 53 climate stations, maps were made of the spatial distribution of precipitation for the period of the year and winter and summer half-year. The kriging method was used to map rainfall distribution in Poland. In the case study, cross-validation was used to compare the prediction performances of three periods. Kriging, with exponential type of semivariogram, gave the best performance in the statistical sense. Their application is justices especially in areas where landform is very complex. In accordance with the assumptions, the mean prediction error (ME), mean standardized prediction error (MSE), and root mean-square standardized prediction error (RMSSE) values are approximately zero, and root-mean-square prediction error (RMSE) and average standard error (ASE) reach values well below 100.

7

Analysis of Spatial Variability of Selected Soil Properties in the Hard Coal Post-Mining Area

Klatka Sławomir Tomasz, Malec Magdalena, Ryczek Marek

Journal of Ecological Engineering

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2019

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Vol. 20, nr 3

185--193

EN

The result of geomechanical and hydrological degradation caused by the underground extraction of hard coal are the transformations of the environmentally managed terrains and high variability of soil properties occurring in these areas. The analysis of selected soil properties of spatial variability in the post-mining area conducted by means of the kriging technique was presented in the paper. The determined points of empirical semivariogram were described by means of mathematical functions and theoretical semivariograms were plotted. The conducted analysis allowed to plot the maps of variability isolines, which my provide a basis to delineate the boundaries of areas most susceptible to the hydrological degradation of soils. The obtained research results indicate that the applied kriging technique may prove to be a useful tool for determining spatial variability of soils in the areas of hard coal mining operations and allow to delineate the boundaries of the areas most susceptible to soil degradation.

8

Temporal stability of soil apparent electrical conductivity (ECa) in managed podzols

Badewa Emmanuel, Unc Adrian, Cheema Mumtaz, Galagedara Lakshman

Acta Geophysica

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2019

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Vol. 67, no. 4

1107--1118

EN

The spatial variability in soil physical and hydraulic properties for a managed podzol was assessed using soil apparent electrical conductivity (ECa). Two EMI sensors, the multi-coil (MC) and multi-frequency (MF), were adopted for measurement of ECa on a silage- corn experimental plot in western Newfoundland, Canada. Results demonstrated a significant relationship between the ECa mean relative differences (MRD) and the soil moisture content MRD (R2=0.33 to 0.70) for both MC and MF sensors. The difference in depth sensitivity between MC and MF sensors accounted for the variation (0.015 to 0.09) in ECa standard deviation of the relative differences. A significant linear relationship was found between the ECa MRD and sand (R2=0.35 and 0.53) or silt (R2=0.43), but not with clay (R2=0.06 and 0.16). The spatial variability of the ECa-based predictions (CV=3.26 to 27.61) of soil properties was lower than the measured values (CV=5.56 to 41.77). These results inferred that the temporal stability of ECa might be a suitable proxy to understand the spatial variability of soil physical and hydraulic properties in agricultural podzols.

9

Spatial Variability of Chosen Soil Properties on Mountainous Area on Example of the Kasinczanka Stream Basin, Western Carpathians

Kruk E., Ryczek M., Klatka S., Malec M.

Journal of Ecological Engineering

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2018

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Vol. 19, nr 3

146--153

EN

The phenomenon of erosion on mountain and submontane areas influences directly on high variability of soil properties. In the work there were presented results of analysis of spatial variability of bulk density, total porosity, organic matter content and saturated hydraulic conductivity, on eroded slopes of the Kasińczanka stream basin. Geostatistical analysis was carried out using the kriging method, based on irregular network, consisted of 52 points, situated by means of the GPS. Taking into account the calculated variability coefficient it was stated, that on the investigated area, the most flexible spatially was saturated hydraulic conductivity, while the less flexible turned out total porosity. Using the determined models of semivariance, the maps of spatial variability of chosen parameters were drafted. It was stated that high value of variance influenced on higher smoothing of spatial distribution in interpolation. Results of geostatistical analysis will allow to find locations for new measuring points, what has substantial significance in mountain areas, for precision analysis of soil properties. Based on the obtained results, it can be stated that the kriging method may be useful tool for determination spatial variability analysis of soil properties on an areas of mountain basins.

10

Soil Sequences Along a Slope of the Opalenica Plain

Kozłowski M., Komisarek J.

Journal of Ecological Engineering

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2016

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Vol. 17, nr 1

69—76

EN

The paper presents the results of a study on differentiation of the morphological structure of soil and selected physical and chemical properties of soils in toposequence of the Opalenica Plain. The study was conducted in a 1200 m long transect running through a typical soil toposequence for the Polish Lowland, and therefore the results presented in this study can be extrapolated to similar geomorphological conditions of the area. On the basis of pedological cross-section, the following soil units were distinguished: PWspgl – Albic Luvisols (Arenic) with glossic properties, PAt – Albic Glossic Retisols (Loamic), PAsp – Albic Glossic Retisols (Aric, Arenic), PAspgg – Albic Glossic Retisols (Aric, Arenic, Oxyaquic), PWsggl – Albic Luvisols (Aric, Arenic, Stagnic) with glossic properties, PWgggl – Albic Luvisols (Aric, Loamic, Stagnic) with glossic properties, CZgg – Mollic Reductigleyic Eutric Gleysols (Aric, Loamic), CFt – Fluvic Phaeozems (Aric, Arenic). Each of these units has its own specific position in toposequence but the occurrence of Fluvic Phaeozems (Aric, Arenic) are associated with geogenetic processes of Mogilnica river. In this work, using a multiple regression analysis a statistically significant relationships between the position of the soils in relief and the terrain slopes and the organic carbon content in Ap horizon, the cation exchangeable capacity, the sum of exchangeable bases and the pH were obtained. Systematic variability of most soil properties of Ap horizon have shown two distances of spatial variation. The first concerns the systematic changes in shorter distance (from 132 to 344 m) and can be associated with differences in soil properties between separate soil units. The second distance of spatial correlation ranges from 431 m to 792 m, which testify to the fact that quantitative changes in the properties of soils are realized gradually and distinctly, together with the differentiation of the slope, over several separate cartographic units.

11

Ocena przestrzennej zmienności występowania opadów atmosferycznych w Centralnej Polsce w latach 2013-2015

Wójcik K., Treder W., Zbudniewek A.

Infrastruktura i Ekologia Terenów Wiejskich

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2016

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nr I/1

73--87

PL

W warunkach klimatycznych Polski opady atmosferyczne są podstawowym źródłem wody dla roślin. Klimat Polski określany jest jako przejściowy, zmienny i kontrastowy. Zmienny jest także rozkład opadów w czasie sezonu wegetacyjnego, w tej samej porze roku mogą występować wielodniowe okresy bezopadowe lub długotrwałe nadmierne opady. Opady charakteryzują się różną wielkością i intensywnością. Celem podjętych badań była analiza przestrzennej zmienności opadów atmosferycznych w centralnej Polsce. Dane pomiarowe obejmowały okresy wegetacyjne od IV do X w latach 2013-2015. Analiza wyników potwierdza opinię o bardzo dużej zmienności sum opadów, ich maksymalnych wysokości i intensywności oraz długości ciągów dni z opadem i bez opadów. Różnice wykazano na stacjach położonych nawet bardzo blisko siebie. Na podstawie przeprowadzonej analizy można stwierdzić, że opady powinny być mierzone bezpośrednio w miejscu, dla którego szacowany jest bilans wodny.

EN

In Polish climatic conditions rainfall constitutes the main source of water for vegetation. The climate of Poland is characterized by high temporal and spatial variation. The total amount and seasonal distribution of precipitation show significant variability. The aim of the study was to analyze spatial changeability of rainfall in Central Poland. Data concerning rainfall were collected during the vegetative seasons of April - October in years 2013 - 2015. Analysis of the results confirms the observation which states that there is a great spatial variability of sum of precipitation, its maximum amount and intensity as well as the length of dry and rainy periods. Significant differences were observed between the stations located very close to each other. On the basis of obtained results it is stated that the rainfall must be measured directly on the area for which the water balance is to be estimated.

12

Analysis of the spatial variability of the concentrations of Na+ and K+ ions in the groundwater sourced in Southern Poland

Kotowski T., Satora S.

Environment Protection Engineering

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2016

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Vol. 42, nr 2

5--18

EN

Differences in the spatial variability of Na+ and K+ ion concentrations in the groundwater sourced in Southern Poland have been analysed. The study was based on selected hydrogeological environments differing in the lithology and geometry of aquifer rock voids. The hydrogeochemical background for Na+ and K+ ions was determined for various hydrogeological environments as well. The hydroge-ochemical background ranges obtained do not deviate significantly from the background ranges for groundwater observed in other areas of Poland. The analyses conducted indicate the presence of anomalous concentrations of Na+ and K+ ions in all hydrogeological environments often accompanied with significantly elevated concentrations of Cl- and SO42– ions. Owing to the fact that the data analysed exhibit a distribution deviating considerably from a normal one, non-parametric methods of statistical inference were used. The results obtained indicate statistically significant differences between the variabilities of Na+ and K+ ion concentrations in various hydrogeological environments. The factors responsible for such differences are lithological variability and different groundwater circulation systems.

13

Technical note: Comparison between two methods for estimating the vertical scale of fluctuation for modeling random geotechnical problems

Pieczyńska-Kozłowska J.

Studia Geotechnica et Mechanica

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2015

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Vol. 37, nr 4

95--103

EN

The design process in geotechnical engineering requires the most accurate mapping of soil. The difficulty lies in the spatial variability of soil parameters, which has been a site of investigation of many researches for many years. This study analyses the soilmodeling problem by suggesting two effective methods of acquiring information for modeling that consists of variability from cone penetration test (CPT). The first method has been used in geotechnical engineering, but the second one has not been associated with geotechnics so far. Both methods are applied to a case study in which the parameters of changes are estimated. The knowledge of the variability of parameters allows in a long term more effective estimation, for example, bearing capacity probability of failure.

14

Tree-ring based temperature reconstruction for the west Qinling Mountains (China): linkages to the High Asia, solar activity and Pacific-Atlantic Ocean

Chen F., Yuan Y., Wei W., Yu S., Shang H., Zhang T., Zhang R., Wang H., Qin L.

Geochronometria

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2014

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Vol. 41, no. 3

234--244

EN

We developed a Faxon fir (Abies faxoniana) tree-ring width chronology at the timberline in the western Qinling Mountains, China. Herein February–July mean temperature was reconstructed for Zhouqu in the western Qinling Mountains back to AD 1650 based on the standard chronology. The climate/tree-growth model accounts for 43.5% of the instrumental temperature variance during the period 1972–2006. Spatial correlation analyses with the gridded temperature data shows that the tem-perature reconstruction captures regional climatic variations over central and southeast China, and strong teleconnections with the nearby High Asia. There is a good agreement with cold and warm pe-riods previously estimated from tree-rings in Nepal, India and southwest China. The temperature re-construction indicates that there was pronounced cooling in Zhouqu during the Maunder Minimum (late 1600s to early 1700s). The cold period (1813–1827) of the temperature reconstruction coincide with the volcanic eruptions. Significant spectral peaks are found at 56.9, 22.3, 11.4, 2.9, 2.8, 2.6, 2.2 and 2.0 years. The spatial correlation patterns between our temperature reconstruction and SSTs of the Atlantic and Pacific Oceans suggest a connection between regional temperature variations and the atmospheric circulations. It is thus revealed that the chronology has enough potential to reconstruct the climatic variability further into the past.

15

Zróżnicowanie zawartości N-ogółem oraz aktywności enzymów przemian azotu w glebie płowej i czarnej ziemi regionu Pomorza i Kujaw

Piotrowska-Długosz A., Długosz J., Kobierski M., Wilczewski E.

Proceedings of ECOpole

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2013

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Vol. 7, No. 1

229--235

PL

Celem badań było określenie zróżnicowania zawartości N-ogółem (NOG) oraz aktywności ureazy (UR), nitroreduktazy (NR) i poziomu amonifikacji argininy (ADA) w poziomie powierzchniowym gleby płowej oraz czarnej ziemi regionu Pomorza i Kujaw. W tym celu w kwietniu 2007 roku z obu obszarów pobrano po 50 próbek glebowych z punktów zlokalizowanych w sztywnej siatce kwadratów (10m x 10m). Wyniki badań opracowano metodami statystycznymi, a zmienność przestrzenną wybranych parametrów określono za pomocą map rastrowych oraz korelogramów, przedstawiających korelacje przestrzenne badanych zmiennych. Średnia zawartość N-ogółem w glebie płowej wynosiła 0,80 g•kg–1, natomiast w czarnej ziemi 1,80 g•kg–1. Aktywność ureazy mieściła się w zakresie 7,30-19,3 mg NH4 +•kg–1•h–1 w czarnej ziemi oraz 0,16-0,68 mg NH4 +•kg–1•h–1 w glebie płowej, natomiast poziom amonifikacji argininy wynosił średnio 4,09 mg NH4 +•kg–1•h–1 w czarnej ziemi oraz 1,31 mg NH4 +•kg–1•h–1 w glebie płowej. Aktywność nitroreduktazy była zbliżona w obu typach badanych gleb. Wyniki aktywności NR cechowały się wysokim zróżnicowaniem, co potwierdziły współczynniki zmienności wynoszące CV = 41,9% w glebie płowej oraz CV = 106,2% w czarnej ziemi, natomiast aktywność UR i ADA oraz zawartość N-ogółem wykazywała średnie zróżnicowanie (CV od 16 do 35%). Większość badanych zmiennych miała skośność dodatnią, a jedynie wyniki zawartości NOG w czarnej ziemi oraz aktywności UR w glebie płowej wykazywały ujemne wartości skośności. Kurtoza mieściła się w zakresie od –1,369 do 8,909 i dla większość badanych cech była ona dodatnia, co świadczy o większej koncentracji wyników wokół średniej w porównaniu do rozkładu normalnego. W obu badanych glebach najwyższe współczynniki korelacji prostej uzyskano pomiędzy zawartością CORG i NOG. Korelogramy wykazały, że badane zmienne charakteryzowały się zróżnicowaną korelacją przestrzenną, a największą korelację wykazywała aktywność NR w próbkach czarnej ziemi. Mapy przestrzennego rozmieszczenia wyników badanych zmiennych wykazały, że rozmieszczenie wartości każdej z nich wykazywało inny kierunek. Ponadto wartości danej cechy były odmiennie rozmieszczone w obu typach gleb.

EN

The objective of this study was to evaluate and compare the spatial differentiation of total-N content and urease (UR), nitrate reductase (NR) and arginine deaminase (ADA) activities in the surface horizon of Luvisol and Phaeozem of the Pomorze and Kujawy region. 50 soil samples from both study areas were collected in April 2007 in a square sampling grid (90 m x 40 m). The results were evaluated with the use of classic statistical and modern geostatistical methods. Spatial variability of the investigated parameters was evaluated by using empirical semivariograms with adjusted theoretical mathematical model of variograms. Raster maps of the studied properties were drawn. Mean value of total-N content in Luvisol samples was 0.80 g•kg–1, while in case of Phaeozem it amounted to 1.80 g•kg–1. Urease activity ranged 7.30-19.3 mg NH4•kg–1•h–1, while arginine deaminase activity was 4.09 mg NH4•kg–1•h–1 in Phaeozem and 1.31 mg NH4•kg–1•h–1 in Luvisol. The nitrate reductase activity was similar in samples of both types of soils. Differentiation of NR activity was very high, what was confirmed by coefficients of variation values (CV%) amounting for 41.9% in Luvisol and 106.2% in Phaeozem, while UR, ADA activity and total-N content showed a moderate variability (CV = 16-35%). The kurtosis ranged from –1.369 to 8.909 and most of variables studied shown the positive values of this parameter, suggesting higher concentration of the data around the average value compared with the normal distribution. In both soil studied the highest positive correlation coefficients were found between CORG and NTOT content. Correlograms displayed various spatial correlation of properties determined and the highest spatial correlation was calculated for NR activity in Phaeozem. The raster maps showed that the distribution of each variable had the different direction in the area studied and the same variable was distributed diversely in both topsoils.

16

Determining the relation between soil properties and spatial variability of Nitraria schoberi Linn. using geostatistical analysis: a case study in Meighan Playa in Iran

Tilaki G. A. D., Kamarei R., Vafakhah M.

Polish Journal of Ecology

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2013

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Vol. 61, nr 1

93--104

EN

This study is an assessment of the relation of the spatial variability of Nitraria schoberi Linn. to the soil properties conducted by using geo-statistical analysis. In an area of 140 ha a regular network from a semi-arid region of Meighan Playa in central Iran was selected. The results showed that statistically most of the variables fit spherical, exponential and Gaussian models. The lowest and the highest coefficients of variation were found with the soil pH (27%) and the density (66%) of Nitraria schoberi, respectively. The semi-variogram analysis showed that the effective range fluctuated from 150 m for silt to 2563.43 m for the acidity of the soil. The electronic conductivity and soil texture showed more spatial dependency than the organic matter.

17

Temporal pattern prevails over spatial variability in phytoplankton communities from a subtropical water supply reservoir

Lv H., Yang J., Liu L.

Oceanological and Hydrobiological Studies

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2013

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Vol. 42, No. 4

420--430

EN

Phytoplankton species are dominant components in reservoir ecosystems, yet little is known about their variability and dynamics, especially along the depth continuum. This study examined vertical and horizontal differences in phytoplankton communities in a typical subtropical deep reservoir (i.e. Dongzhen Reservoir) from 2011 to 2012. Phytoplankton communities separated into four groups based on the biomass data, indicating that temporal differences in the community structure were greater than spatial differences. Autumn communities had the highest diversity measured by the Shannon-Wiener index (2.47±0.07), while summer communities had the lowest diversity (0.46±0.09). Both winter and spring communities were dominated by diatoms (90.4±1.7%), while cyanobacteria dominated in summer communities during our sampling period. In spring and summer, however, the three surface communities characterized by high biomass were most similar to each other, indicating that vertical variation was significantly higher than horizontal differences. Furthermore, Cylindrospermopsis raciborskii accounted for over 96% of the total phytoplankton biomass in the summer surface water. The redundancy analysis (RDA) illustrated that the temporal factor (summer), the spatial factor (depth), and nutrients (nitrite and nitrate nitrogen, ammonium nitrogen, phosphate phosphorus) were significant variables affecting the dynamics of phytoplankton communities. High temperature with stable thermal stratification might have been the cause of C. raciborskii dominance in Dongzhen Reservoir in summer. Regular and long-term monitoring of dominant species is urgently needed for water quality protection and sustainable reservoir management.

18

Spatial Differentiation of Total Nitrogen Content and the Activity of n-transforming Enzymes in a Soil

Piotrowska-Długosz A., Rybacki M., Długosz J., Kobierski M., Wilczewski E.

Ecological Chemistry and Engineering. A

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2013

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Vol. 20, nr 6

663--674

EN

The objective of this study was to evaluate and compare the spatial differentiation of total N (NTOT) content and urease (UR), nitrate reductase (NR) and arginine deaminase (ADA) activities in the surface horizon of Luvisol and Phaeozem of the Pomerania and Cuiavia region. 50 soil samples from both study areas were collected in April 2007 in a square sampling grid (90 × 40 m). The results were evaluated with the use of geostatistical methods. Spatial variability of the investigated parameters was evaluated by using empirical semivariograms with adjusted theoretical mathematical model of variograms. Raster maps of the studied properties were drawn. The concentration of chemical properties (TN, TOC, pHKCl) and the activity of UR and ADA was significantly higher in Phaeozem compared to Luvisol. Only the nitrate reductase activity was similar in samples of both types of soils. To characterise the spatial variability of the properties studied, spherical or mixed (spherical/linear) models with or without the nugget effect (only NR activity in Luvisol), were fitted to the calculated semivariograms. Total N content, NR activity in Phaeozem and ADA activity in Luvisol were in the strong variability class (the nugget effect < 25 %), while UR activity in both soil types and ADA activity in Phaeozem were situated in the moderate variability class (the nugget effect between 25 and 75 %). The ranges of influence calculated for properties studied ranged from 9.0 to 17 m. The raster maps showed that the distribution of each variable had a different pattern on the area studied. A specific variable was distributed in both topsoils in a different way.

PL

Celem badań było określenie zmienności przestrzennej zawartości N-ogółem (TN) oraz aktywności ureazy (UR), nitroreduktazy (NR) i poziomu deaminacji argininy (ADA) w poziomie powierzchniowym gleby płowej oraz czarnej ziemi regionu Pomorza i Kujaw. W kwietniu 2007 r. z obu obszarów pobrano po 50 próbek glebowych z punktów zlokalizowanych w sztywnej siatce kwadratów (90 × 40 m). Wyniki zmienności przestrzennej badanych parametrów określono za pomocą empirycznych variogramów oraz map rastrowych. Zawartość parametrów chemicznych (TN, TOC, pHKCl) oraz aktywność UR i ADA były większe w czarnej ziemi w porównaniu do gleby płowej. Jedynie aktywność nitroreduktazy była zbliżona w obu typach badanych gleb. Zmienność przestrzenną badanych parametrów przedstawiono za pomocą sferycznych lub mieszanych (sferyczno-liniowych) modeli semivariogamów. Zawartość N ogółem, aktywność NR w czarnej ziemi oraz ADA w glebie płowej znajdowały się w niskiej klasie zmienności (wariancja samorodka < 25 %) natomiast aktywność UR w obu typach gleb oraz ADA w czarnej ziemi zaliczono do średniej klasy zmienności. Zakresy autokorelacji badanych zmiennych wynosiły od 9 do 17 m. Mapy przestrzennego rozmieszczenia wyników badanych zmiennych wykazały, że rozmieszczenie wartości każdej z nich wykazywało inny kierunek. Ponadto wartości danej cechy były odmiennie rozmieszczone w obu typach gleb.

19

The impact of a non-uniform land surface on the radiation environment over an Arctic fjord - a study with a 3D radiative transfer model for stratus clouds over the Hornsund fjord, Spitsbergen

Rozwadowska A., Górecka I.

Oceanologia

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2012

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No. 54 (4)

509-544

EN

This paper estimates the influence of land topography and cover on 3D radiative effects under overcast skies in the Arctic coastal environment, in particular in the Hornsund fjord region, Spitsbergen. The authors focus on the impact of a non-uniform surface on: (1) the spatial distribution of solar fluxes reaching the fjord surface, (2) spectral shortwave cloud radiative forcing at the fjord surface, (3) the solar flux anomaly at the domain surface resulting from the assumption of a uniform surface, i.e. the error due to plane parallel assumptions in climate models, and (4) remote sensing of cloud optical thickness over the fjord. Their dependence on spectral channel, cloud optical thickness, cloud type, cloud base height, surface albedo and solar zenith angle is discussed. The analysis is based on Monte Carlo simulations of solar radiation transfer over a heterogeneous surface for selected channels of the MODIS radiometer. The simulations showed a considerable impact of the land surrounding the fjord on the solar radiation over the fjord. The biggest differences between atmospheric transmittances over the fjord surface and over the ocean were found for a cloud optical thickness τ = 12, low solar zenith angle υ, high cloud base and snow-covered land. For τ= 12, υ = 53°, cloud base height 1.8 km and wavelength λ= 469 nm, the enhancement in irradiance transmittance over the fjord was 0.19 for the inner fjords and 0.10 for the whole fjord (λ = 469 nm). The land surrounding the Hornsund fjord also had a considerable impact on the spectral cloud radiative forcing on the fjord surface and the solar flux anomaly at the domain surface due to the uniform surface assumption. For the mouth and central part of the fjord the error due to the use of channel 2 of the MODIS radiometer (λ = 858 nm) for cloud optical thickness retrieval was < 1 in the case of low-level clouds (cloud base height 1 km, nadir radiance, υ = 53°, cloud optical thickness retrieved solely from MODIS channel 2). However, near the shoreline (up to 2 km from it), especially over the inner fjords, the cloud optical thickness was then overestimated by > 3 for τ = 5 and by > 5 for τ = 20.

20

Analiza przestrzennej zmienności wybranych cech budowy pionowej drzewostanu na podstawie danych lotniczego skanowania laserowego

Zarzecka M., Będkowski K.

Archiwum Fotogrametrii, Kartografii i Teledetekcji

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2012

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Vol. 23

501--507

PL

Jednym z ważniejszych elementów opisu aktualnego stanu drzewostanów jest informacja o ich budowie pionowej (układzie warstw). Informacje te gromadzone są w ramach okresowych inwentaryzacji zasobów leśnych. Z uwagi na dużą pracochłonność mają one jednak charakter bardzo ogólny, gdyż są odnoszone do stosunkowo dużych fragmentów lasu. Poszukuje się sposobów pozwalających na uzyskanie informacji o budowie niedużych fragmentów drzewostanów, o wielkości kilku- kilkunastu arów. Lotniczy skaning laserowy z powodzeniem jest wykorzystywany przez leśników do określania wysokości drzewostanów, liczby drzew w drzewostanie oraz wielkości jego biomasy. Dostrzeżono także możliwość rozpoznawania za pomocą skanowania laserowego pionowej budowy drzewostanów. Przeprowadzono badania w drzewostanie z sosną pospolitą w górnym piętrze, które miały na celu sprawdzenie możliwości detekcji dolnej warstwy podszytu składającego się z gatunków liściastych. Wykonano analizę histogramów rozkładów pionowych chmur punktów lotniczego skaningu laserowego. Histogramy przedstawiały liczbę impulsów zarejestrowanych w 0.5 m warstwach: 0÷0.5 m, 0.5÷1. 0, itd. Do opisania kształtu histogramów zaproponowano 7 cech. Stwierdzono, że dzięki ich zastosowaniu możliwe jest rozpoznanie obecności dolnej warstwy w drzewostanie.

EN

One of most important characteristics describing forest is their vertical structure (number of layers). This information is collected during periodical forest inventories. The inventory procedures are time-consuming and can provide only general information, describing relatively big parts of forests. There are still a lot of research activities on the search for methods providing more accurate information. In past aerial laser-scanning was successfully adopted by foresters to determine forest height, number of trees and biomass volume. There was suggested also to use ALS to detect forest vertical structures. This paper describes research made in an Scotch pine (Pinus silvestris) stand with some deciduous species in order to check whether it is possible to detect an forest understory with ALS data. An analysis of histograms describing vertical structure of laser-scanning clouds in half-meter layers was done. Histogram shapes were described with 7 special developed variables V1÷V7. It was found, that there is possible to detect the presence of forest understorey with one of variables.