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Investments in small retention as a factor influencing land-use changes. A case study of Poland

Feltynowski Marcin

Journal of Water and Land Development

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2023

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no. 56

235--241

EN

Building permit decisions are one of the most important elements of the investment process in Poland. It should be noted that water reservoirs influence the diversification of landscapes by increasing their attractiveness in both urban and rural areas. The article aimed to verify the relationship between the changes in land-use development and investments related to small retention. Another goal was classifying objects for which building permits have been obtained and registered. Changes in land-use development associated with the introduction of ponds, which blend in with the landscape, are desirable from the perspective of retaining water resources in urban and rural ecosystems. The research methodology was based on spatial data and included statistical analyses in three regions: Mazowieckie, Lodzkie and Swietokrzyskie. Studies carried out in these regions showed a spatial correlation associated with investments in small retention. The research used methods of the global I Moran statistic and local Moran statistics. The data used in the study came from the Register of Applications, Decisions and Notifications, made available by the Main Office of Construction Site. The research indicates clusters of investments in small retention in analysed regions. The majority of investors are residents who invest in earth ponds. The study shows that investment in small retention is connected with ecosystem services.

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Sensitivity and stability analysis for groundwater numerical modeling: a field study of finite element application in the arid region

Jafarzadeh Ahmad, Pourreza-Bilondi Mohsen, Akbarpour Abolfazl, Khashei-Siuki Abbas, Azizi Mohsen

Acta Geophysica

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2023

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Vol. 71, no. 2

1045--1062

EN

This study intends to investigate the impacts of scheme type, time step, and error threshold on the stability of numerical simulation in the groundwater modeling. Hence, a two-dimensional finite element (FE) was implemented to simulate groundwater flow in a synthetic test case and a real-world study (Birjand aquifer). To verify the proposed model in both cases, the obtained results were compared with analytical solutions and observed values. The stability of numerical results was analyzed through different schemes and time-step sizes. Besides, the effect of the error threshold was examined by considering different threshold values. The results confirmed that the FE model has a good capacity to simulate groundwater fluctuations even for the real problem with more complexities. Examination of implicit outputs indicated that groundwater simulations based on this scheme have good accuracy, stability, and proper convergence in all time intervals. However, in the explicit and Crank–Nicolson schemes the time interval should be less than or equal to 0.001 and 0.1 day, respectively. Also, results reveal that for making stability in all schemes the value of the error threshold should not be more than 0.0001 m. Moreover, it derived that the boundary conditions of the aquifer influence the stability of numerical outputs. Finally, it was comprehended that as time interval and error threshold increases, the oscillation rate propagated.

3

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.

4

Ergodic Channel Capacity of PPM-Coded Optical MIMO Communications Under Combined Effects

Cao Minghua, Zhang Yue, Kang Zhongjiang, Wang Huiqin

International Journal of Electronics and Telecommunications

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2021

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Vol. 67, No. 3

431--436

EN

The ergodic channel capacity of wireless optical multiple-input multiple-output (MIMO) system with pulse position modulation (PPM) is investigated. The combined effects of atmospheric turbulence, atmospheric attenuation, pointing error and channel spatial correlation are taken into consideration. The expression of ergodic channel capacity is derived, and is further performed by Wilkinson approximation method for simplicity. The simulation results indicated that the strong spatial correlation has the greatest influence on the ergodic channel capacity, followed by pointing errors and atmospheric turbulence. Moreover, the ergodic channel capacity growth brought by space diversity only performs well under independent and weakly correlated channels. Properly increasing the size and spacing of the receiving apertures is an effective means of effectively increasing the ergodic channel capacity.

5

Analiza statystyczna i geostatystyczna zróżnicowania przestrzennego parametrów położenia warstw w NW części Gór Świętokrzyskich

Dębowska U., Zawadzki J.

Przegląd Geologiczny

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2005

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Vol. 53, nr 4

306-310

EN

Stratapositions of the Paleozoic rocks in the NW part of Holy Cross Mts are analysed statistically and geostatistically. The study area was subdivided into the eastern and western part. Statistical characteristics allowed to exclude outlier values. Variograms were calculated to determine range of influence of strata position parameters analysis allows to describe the spatial diversity of strike and dip strata value.

6

Stateczność dynamiczna konstrukcji pod wpływem czasowo-przestrzennych obciążeń przypadkowych

Tylikowski A.

Zeszyty Naukowe. Mechanika / Akademia Techniczno-Rolnicza w Bydgoszczy

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2004

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Z. 54(243)

23-32

PL

Obciążenia losowe dużych konstrukcji pochodzące zarówno od wiatru, ruchów skorupy ziemskiej lub fal morskich charakteryzują się przestrzenną korelacją. W pracy przedstawiona jest analiza stateczności dynamicznej typowych konstrukcji jednowymiarowych, takich jak maszty, wieże lub mosty wiszące, poddanych obciążeniu zmiennemu w czasie i przestrzeni prowadzącemu do drgań parametrycznych konstrukcji. Wyprowadzone bezpośrednią metodą Lapunowa dostateczne warunki stateczności wyrażone są przez podstawowe parametry konstrukcji i obciążenia, takie jak współczynnik tłumienia wiskotycznego, wymiary, sztywności oraz intensywności i długości korelacji obciążenia.

EN

Random loadings of wind turbulences, sea waves and the earth's crust acting on large structures are characterized by the spatial correlation. In the present paper dynamic stability of one dimensional structures such as masts, towers, chimneys and suspension bridges subject to space and time dependent loading is investigated. Via Liapunov direct method sufficient stability conditions are derived. The stability conditions are expressed by geometrical and stiffness data, the viscous damping coefficient as well as intensities and correlation lengths of loading.

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Geostatystyczne metody oceny ciągłości i korelacji na przykładzie badań zawartości cynku, ołowiu i żelaza w glebie

Zawadzki J.

Inżynieria i Ochrona Środowiska

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2001

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T. 4, nr 3-4

369-391

PL

Przedstawiono geostatystyczne metody analizy ciągłości i korelacji przestrzennej na przykładzie pomiarów zawartości Zn, Pb i Fe w glebach Warszawy i jej okolic. Przeprowadzono obliczenia izotropowych i anizotropowych wariogramów (oraz wariogramów krzyżowych) zawartości tych metali w glebie. Dodatkowo wykonano mapy wariogramów. Wariogramy modelowano za pomocą kombinacji liniowych modeli podstawowych. Najlepsze dopasowanie wariogramów zawartości Pb i Zn uzyskano, stosując kombinację modelu losowego oraz modelu sferycznego. Wyniki modelowania wariogramów wykazały anizotropię ciągłości przestrzennej Pb i Zn. Największa ciągłość przestrzenna występowała w kierunku północno-wschodnim (odpowiednio 19 i 20 km), najmniejsza zaś w kierunku północno-zachodnim (odpowiednio 12,5 i 12 km). W przypadku Fe trudno było jednoznacznie określić kierunek anizotropii rozkładu przestrzennego, gdyż wariogram zawartości tego metalu był mniej regularny. Przeprowadzono również obliczenia współczynników korelacji Pearsona pomiędzy zawartością Fe, Pb i Zn w glebie. Wartości tych współczynników wynosiły 0,68; 0,19 oraz 0,18 dla Pb-Zn, Fe-Zn oraz Fe-Zn. Dokładne obliczenia korelacji przestrzennej wykonano na podstawie modelowania wariogramów krzyżowych. Wartości współczynników korelacji związanych ze skalą modelu losowego oraz modelu sferycznego wynosiły odpowiednio r1 = 0,42 oraz r2 = 0,50. Współczynnik korelacji związany z modelem sferycznym uwzględnia korelacje przestrzenne i dlatego lepiej odzwierciedla wielkość tych korelacji niż współczynnik korelacji Pearsona.

EN

The description, analysis and interpretation of spatial variability and correlation is an essential part of a geostatistical study. The paper presents the geostatistical methods to study spatial continuity as well as spatial correlation. It focuses on two of the most common geostatistical measures of spatial continuity, the direct variograms and the cross variograms, describes their appropriate uses, their strengths and their weaknesses. The interpretation of experimental measures of spatial variability were discussed and demonstrated with examples based on a data set consisting of Fe, Pb and Zn concentrations in soil measurements collected in Warsaw and its environs. To get a clear picture of the spatial continuity of concentrations studied both the isotropic (omnidirectional) and anisotropic (directional) variograms and the cross variograms were analysed. Then, the empirical variograms of Fe, Pb and Zn concentrations were modelled in terms of a nested model. It was found that the best model variograms of Pb and Zn concentrations consists of a nugget model and a spherical one. A noticeably anisotropic behaviour of concentrations of Pb and Zn in soil Zn was found. The direction of maximum continuity of Pb and Zn concentrations close to N45°E was found. The maximum ranges of the spherical model for this contamination were about 19 and 20 km, for Pb and Zn, respectively. The direction of minimum continuity of Pb and Zn concentrations in soil was close to N45°W with the ranges in this direction equal to about 12.5 and 12 km, respectively. In contrast to well-defined variograms of Pb and Zn concentrations the variogram of Fe concentration shows lack of clear structure. A few maximums and minimums appear on this variogram. Such a phenomenon suggests that samples separated by long distances can be more similar than those separated by short distances. In order to display directional anisotropies of studied metals concentrations in soil the maps of the variograms were also calculated and presented. A second objective of the paper was to determine a correlation between concentration of Fe, Pb and Zn in soil. The obtained values of the Pearson coefficient of correlation r were 0.51,0.19 and 0.18 for Pb-Zn, Fe-Zn and Fe-Pb, respectively. But, a classical direct correlation analysis between the two measured values which are the regionalized variables is very likely to fail. It is due to neglecting of structured aspects of natural phenomena. The concentrations of metals in soil are the regionalized variables not a random ones. Therefore, the Pearson coefficient of correlation is not an appropriate tool for the assessment of correlation among soil contamination with different metals. In order to determine the strength of this correlation the cross variograms of contamination were calculated. The accurate modelling and correlation assessment were possible only in the case of the Pb-Zn cross variograram. The scale-specific correlation coefficients were calculated using the linear model of coregionalization. The correlation coefficient at a scale consistent with the nugget effect was r1 = 0.42 and the one consistent with the range of spherical model was r2 = 0.50. The small value of r1 can be attributed to measurement fluctuations. It can be concluded, that the correlation coefficient consistent with the range of spherical model is probably the best among considered at the paper measures of correlation, because it takes into account spatial correlation, which cannot be neglected in case of regionalized variables.