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1

Effects of the tide on the temporal and spatial physicochemical structure of the Kienké river estuary (South Atlantic Coast of Cameroon, Kribi) and its phytoplankton

Mama Anselme Crépin, Ghepdeu Gisele Flodore Youbouni, Fossi Tankoua Olivia, Bonga Manfred Desire, Abouga-Bodo Willy Karol, Mandeng Thérésa Irma, Owona-Edoa François Désiré, Tangko Noel Chuye, Ngoupayou-Ndam Jules Rémi

Oceanological and Hydrobiological Studies

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2023

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Vol. 52, No. 1

20--40

EN

The present work aimed to understand the physicochemical and phytoplanktonic structure of the Kienke estuary water in the urban area of Kribi town in relation to human activities and fluvial or oceanic influences. Field investigations and laboratory work were devoted to the sampling and measurement of some physicochemical and biological parameters, specific treatments and classical statistics (descriptive, multidimensional) of variables. Estuary water is characterised by an instability and spatio-temporal variations in its physicochemical parameters. The most sensitive parameters are as follows: a temperature ranging between 22.6°C and 31°C under the influence of atmospheric variations, electrical conductivity and salinity that are relatively high (0.22 < C. E < 49.70 mS cm-1; avg =16.56 mS cm-1; 0 < Sal < 29.32 PSU; avg = 11.51 PSU), and a pH that is overall acidic to basic (6 < pH < 8.86; avg = 7.75 ± 0.82). The nutrients variation (ammonium, nitrite, nitrate and orthophosphate) is very low in space and time, with a longitudinal distribution controlled by tidal flows, river flows and the biological pump. For the 64 samples collected, 167 phytoplankton taxa were identified. The most abundant (36.36%) were Chrysophyta Division, followed by Chlorophyta. Species richness is marked by brackish water taxa. According to this structure and the combination of both gradients, mineratilisation and organic matter enrichment is of a physicochemical typology, and the biotypology is hydrotypologically dependent.

2

Effects of human activities in the coastal zone of Laizhou Bay

Wang Min, Han Mei, Hui Hongkuan, Li Yunlong

Ecological Chemistry and Engineering. S

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2021

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Vol. 28, nr 2

219--227

EN

The serious destruction of resources and environment in Laizhou Bay has attracted extensive attention of researchers. This study mainly analysed the changes of fish structure and environment in the coastal zone of Laizhou Bay caused by human activities. By consulting literatures and field measurements, the changes of dominant fish species, coastline and sea water intrusion were analysed. The results showed that dominant fish species in Laizhou Bay change from high-economic species to low-economic species under the influence of human activities, and the coastline erosion was serious, and the area of sea water intrusion was also increasing year by year. It is concluded from the research results that human activities had a significant impact on the structure of fish school and the environment. It is necessary to arrange human activities in an appropriate amount to reduce the overexploitation of resources in order to restore the fishery resources and environment in Laizhou Bay.

3

Response of the rotifer community to human-induced changes in the trophic state of a reservoir

Kim Seong-Ki, Kim Jeong-Cheol, Joo Jeong-Cheol, Choi Jong-Yun

Oceanological and Hydrobiological Studies

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2020

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Vol. 49, No. 4

329--344

EN

Human disturbance and nutrient runoff lead to water pollution, particularly in downstream waters and reservoirs. We hypothesized that increased human activity in summer would affect the trophic state of downstream reservoirs, affecting the interannual species composition of rotifers. We used long-term data for the Unmun Reservoir in South Korea (2009–2015), which is increasingly affected by human activity. The interannual variation of nitrogen and phosphorus levels was higher in summer and autumn, resulting in eutrophication. This led to a change in species composition of rotifers. Anuraeopsis fissa, Brachionus calyciflorus and Trichocerca gracilis were abundant in the most eutrophic state, while high densities of Ascomorpha ovalis and Ploesoma hudsoni were observed when nutrient concentrations were lower. The trophic state changes in the Unmun Reservoir were largely attributed to summer human activity in tributary streams. Our study location is typical of the stream network in South Korea and we assume that similar trophic state changes in reservoirs will be common. Changes in the density and species diversity of rotifers due to eutrophication indicate the need for active management and conservation, including the restriction of human activity around streams.

4

Channel characteristics and planform dynamics of the lower Niger River, Niger Delta Basin (1985–2015)

Akana Tombra, Adeigbe Olubunmi

Geology, Geophysics and Environment

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2019

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Vol. 45, no. 4

291--304

EN

This study used repeat satellite imagery and Geographic Information System analysis to assess the planform dynamics along the length of the lower Niger River Valley from Onitsha city to the coast between 1985 and 2015. The aim is to understand the altered dynamics and its plausible causes in this data-poor region. Analyses revealed that the Niger River has undergone change corresponding to enhanced instability in terms of an increased rate of erosion. In the study area, a change was observed from 3.7% of deposition in the first 10 years (1985–1995) to 3.9% of erosion in the next 10 years (1995–2005) and 4.7% of erosion in the last 10 years (2005–2015). Total erosion over the 30-year period (1985–2015) in the delta was calculated on 4.8%. The river channel has migrated toward the east in the upper and lower reaches while the mid-section of the channel is migrating towards the west. The east river bank is observed to be more unstable compared to west bank line through the study period. The maximum shifts identified were 3.35 km of deposition in 10 years (1985–1995), 3.31 km of erosion in the next 10 years (1995–2005), and another substantial erosional shift of 3.35 km in the next 10 years (2005–2015). Avulsion rates gradually moved from −42.1 m ∙ year−1 (1985–2005, segment F) to 100.2 m ∙ year−1 (1985–1995, segment D), large deposition in the first 10 years. Total avulsion rates of the delta in the last 30 years (1985–2015) has pointed on erosion (−2.2 m ∙ year−1). The altered dynamics observed would likely threaten the future of the fragile lower river system environment and raise concerns for operators with infrastructure within the Niger Delta.

5

Geostatistical analysis of hydrochemical variations and nitrate pollution causes of groundwater in an alluvial fan plain

Yin Shiyang, Xiao Yong, Gu Xiaomin, Hao Qichen, Liu Honglu, Hao Zhongyong, Meng Geping, Pan Xingyao, Pei Qiuming

Acta Geophysica

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2019

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Vol. 67, no. 4

1191--1203

EN

Geostatistics was used in a typical alluvial fan to reveal its applicability to spatial distribution analysis and controlling mechanisms of groundwater chemistry. Normal distribution test and optimal geostatistical interpolation models for various groundwater quality indicators were discussed in this study. The optimal variogram model of each indicator was determined using prediction error analysis. The infuences of human activities and structural factors on the groundwater chemistry were also determined by variability intensity and the sill ratio. The results showed that nitrate content can be served as groundwater quality indicator, which was most sensitive to human activities. The nitrate concentration of both shallow and deep groundwater showed a decreasing trend from the northwest to the southeast. In addition, the spatial distribution of groundwater nitrate was associated with the land-use type and the lithological properties of aquifer. Rapid urbanization in the northwestern part intensifed groundwater extraction and aggravated the pollutant input. The central area showed little increase in nitrate content in the shallow and deep groundwater, and the efect of lateral recharge from the upstream water on the deep groundwater in the central area was greater than that of the vertical recharge from shallow groundwater. The present study suggests that geostatistics is helpful for analyzing the spatial distribution and distinguishing the infuences of anthropogenic and natural factors on groundwater chemistry.

6

Temporal characteristics detection and attribution analysis of hydrological time-series variation in the seagoing river of southern China under environmental change

Chen L., Wang Y., Touati B., Guan H., Leng G, Liu W., Lv S., Huang S., Pan Z.

Acta Geophysica

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2018

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Vol. 66, no. 5

1151--1170

EN

Environmental changes have led to a growing conflict between water supply and demand in Qinjiang River. This paper used the data of monthly rainfall, runoff, evaporation and air temperature during the period from 1956 to 2016 and combined 3-year running mean, linear regression method, Mann–Kendall test and R/S analysis method to analyze the change trend of each factor, combined Mann–Kendall test, cumulative anomaly method and slide t test to analyze the variation of each factor and combined Morlet continuous wavelet analysis to identify periodic oscillations. In this paper, the influences of climate change and human activities on the runoff of the Qinjiang River were qualitatively assessed from the aspects of trend, variation and periodicity and the contributions of climate change and human activities to runoff reduction were quantitatively assessed using evaporation difference method and an improved comparative method of the slope changing ratio of cumulative quantity (SCRCQ).The following results were obtained: (1) From 1956 to 2016, the rainfall showed a weak increasing trend, whereas the runoff depth and the evaporation exhibited significant decreasing trend and the air temperature exhibited a significant increasing trend. The rainfall and air temperature will continuously increase, whereas runoff and evaporation will continuously decrease in the future. (2) Rainfall exhibited no significant variation, whereas there were two variation points (1986 and 2003) in the runoff, three variation points (1974, 1986 and 2011) in evaporation and one variation point (1996) in air temperature. (3) Features of rainfall exhibited similarities to periodic changes in runoff, whereas rainfall exhibited significant difference with evaporation and air temperature. (4) Human activities contributed mainly to the runoff reduction. The contribution of human activities to runoff reduction increased from 43.78 to 61.17% in BR period (1983–2003) and increased from 61.17 to 72.66% in CR period (2004–2016). This indicated that the contribution of human activities to runoff reduction increased continuously. The impact of human activities on the reduction in runoff in the Qinjiang River Basin is mainly due to the irrigation, industrial and urban residents’ water use, which is caused by the growth of population and the growth of economic index.

7

Historyczne aspekty zabezpieczenia logistycznego działań sił morskich

Szubrycht T.

Gospodarka Materiałowa i Logistyka

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2016

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nr 12

714--730

PL

Aktywność ludzka na morzu w znacznie większym stopniu uzależniona od zabezpieczenia logistycznego, niż działalność na lądzie. Na przestrzeni wieków skala i zakres zabezpieczenia logistycznego działań okrętów ulegał zmianom, było to spowodowane m.in.: rozwojem uzbrojenia okrętowego, zwiększeniem liczby członków załogi na okrętach, zmianami wyposażenia okrętów, czasem przebywania okrętów na morzu oraz rejonem pływania. W artykule przedstawiono wybrane aspekty historycznej analizy procesu ewolucji szeroko postrzeganego zabezpieczenia logistycznego działań okrętów na morzu w epoce: wioseł, żagli, pary i ropy naftowej. Warto zauważyć, iż każda epoka miała charakterystyczne wyzwania logistyczne, którym musiały sprostać osoby odpowiedzialne za ten aspekt działania sił morskich. Na podstawie analiz zawartych w artykule można stwierdzić, iż tak naprawdę na przestrzeni wieków zmianom ulegała jedynie skala niezbędnych działań, a nie charakter zabezpieczenia logistycznego sił morskich.

EN

Human activities at sea to a much greater extent dependent upon securing the logistics-go, than those on land. Over the centuries, the scale and scope of logistic activities purse-shapes was changing, it was caused by m.in .: development of weapons ship, increasing the number of crew members on ships, marine equipment changes, the residence time of ships at sea and the region of swimming. The article presents selected aspects of the historical analysis of the evolutionary process widely perceived logistical operations of ships at sea in the age: oars, sails, steam and oil naf-evaporator. It is worth noting that every era had specific logistics challenges, which have to meet the people responsible for this facet of the naval forces. Based on the analysis contained in the article it can be concluded that it really changed over the centuries underwent only the scale of the necessary actions, and not the nature of logistical naval forces.

8

Playful interactions between space and the audience

Piądłowska K.

Czasopismo Techniczne. Architektura

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2015

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Y. 112, iss. 9-A

261--268

EN

Architecture very often interacts with people by showing them different types of behaviour and provoking specific actions. This article discusses public spaces of various specificity whose shapes, textures, and hidden values and symbols exert an impact on people’s mood, their ways of spending free time, and even on the formation of social relations.

PL

Architektura nierzadko wchodzi w interakcję z człowiekiem, sugerując mu różne formy zachowana, wywołując określone aktywności. W tekście przeanalizowano przestrzenie publiczne o odmiennej specyfice, w których różnorodna atmosfera, kształt, faktura i ukryte wartości i symbole, wpływają na nastrój jednostki, sposób spędzania czasu a nawet na budowanie relacji międzyludzkich.

9

Short-range noise radar with microwave correlator for through-the-wall detection

Susek W., Stec B.

Metrology and Measurement Systems

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2013

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Vol. 20, nr 3

351--358

EN

The analysis of the autocorrelation function of a noise signal in a limited band of a microwave frequency range is described in the paper. On the basis of this analysis the static characteristic of the detector for object movement was found. The measurement results for the correlation function of noise signals are shown and the application of such solution in a noise radar for the precise determination of distance variations and the velocity of these changes is presented in the paper. The construction, working principle and measurement results for through-thewall noise radar demonstrator have been presented in the paper. A broadband noise signal in microwave S frequency band has been chosen, for high sensitivity getting. The broadband noise signal together with correlation receiver provides high sensitivity and moderate range for low transmitted power level. The experimental results obtained from 2.6-3.6 GHz noise-like waveform for the signal of a breathing human are presented. Conclusions and future plans for application of the presented detection technique in broadband noise radars conclude the paper.