Spatial distribution and temporal variation of methane, ethane and propane background levels in shallow aquifers – A case study from Lower Saxony (Germany)

During the seven-year research period, the average annual removal was by 3274 m3 higher than the average annual removal prescribed by the existing management plan (MP). The main reason lies in the high amount of salvage felling volume at 55,238 m3 (38.3%) in both the main and the intermediate felling due to oak dieback. The analysis of forest accessibility took into account the spatial distribution of cutblocks (with ongoing felling operations) and the volume of felled timber for two proposed factors: (1) the position of the cutblock and (2) the position of the removal. Cutblock position factor took into account the spatial position of the felling areas/sites, while removal position factor besides the spatial reference took into account the amount of felled timber (i.e., volume) both concerning forest infrastructure network and forest operations. The analysed relative forest openness by using geo-processing workflows in GIS environment showed four types of opening areas in the studied management unit (MU): single-opened, multiple-opened, unopened and opened areas outside of the management unit. Negative effects of the piece-volume law and low harvesting densities on forest operations are highlighted in this research due to high amount of salvage felling particularly in the intermediate felling by replacing timber volume that should have come from thinnings.

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Spatial distribution of urban gardens on vacant land and rooftops: A case study of 'The Garden City Initiative' in Taipei City, Taiwan

Urban Geography ◽

10.1080/02723638.2021.1901036 ◽

2021 ◽

pp. 1-26

Author(s):

Hongwei Hsiao

Keyword(s):

Spatial Distribution ◽

Vacant Land ◽

Garden City ◽

Urban Gardens ◽

Taipei City

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Spatial distribution of microplastics in the fluvial sediments of a transboundary river – A case study of the Tisza River in Central Europe

The Science of The Total Environment ◽

10.1016/j.scitotenv.2021.147306 ◽

2021 ◽

Vol 785 ◽

pp. 147306

Author(s):

Tímea Kiss ◽

Szilveszter Fórián ◽

Gábor Szatmári ◽

György Sipos

Keyword(s):

Spatial Distribution ◽

Central Europe ◽

Fluvial Sediments ◽

Transboundary River ◽

Tisza River

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Spatial distribution and temporal variation of microcrustaceans assembly (Cladocera and Copepoda) in different compartments of a reservoir in the brazilian semiarid region

Acta Limnologica Brasiliensia ◽

10.1590/s2179-975x9616 ◽

2018 ◽

Vol 30 (0) ◽

Cited By ~ 1

Author(s):

Josiane Souza Santos ◽

Nadson Ressyé Simões ◽

Sérgio Luiz Sonoda

Keyword(s):

Spatial Distribution ◽

Spatial Variation ◽

Temporal Variation ◽

Aquatic Macrophytes ◽

Temporal Dynamics ◽

Lateral Compartment ◽

Spatial And Temporal Variation ◽

Semiarid Region ◽

Brazilian Semiarid ◽

Significant Spatial Variation

Abstract Aim: The objective of this study was to investigate the spatial and temporal variation of microcrustacean assemblages of a reservoir in the Brazilian semiarid region. Methods Physical and chemical water variables and samples of microcrustaceans were collected at eight sites of the reservoir between July 2013 and November 2014, in a total of seven campaigns. For this study, the reservoir was categorized in two compartments: lateral and central. Results Limnological variables showed significant temporal variation (PERMANOVA, Pseudo-F = 19.51, p = 0.001). Higher turbidity values and suspended solids were observed in the rainiest months, while during the dry months, we measured higher values of transparency, dissolved oxygen, and chlorophyll-a. It was not found significant spatial variation of limnological variables (PERMANOVA, Pseudo-F = 0.96; p = 0.394). During the study period, ten species were recorded: four Cladocera (Ceriodaphnia cornuta, Daphnia gessneri, Diaphanosoma birgei and Diaphanosoma spinulosum ) three Copepoda Calanoida (Argyrodiaptomus azevedoi, Notodiaptomus cearensis and Notodiaptomus iheringi) and three Copepoda Cyclopoida (Macrocyclops albidus, Thermocyclops minutus and Thermocyclops decipiens). The microcrustacean assemblages showed significant temporal variation (PERMANOVA, Pseudo-F = 4.34; p = 0.001) as well as significant spatial variation (PERMANOVA, Pseudo-F = 9.46; p = 0.001). The highest values of abundance and richness were observed in the lateral compartment, this result is mainly related to the presence of aquatic macrophytes in this region, because the analysis of partial RDA indicated that limnological variables explained only 11% of this variation (Pseudo-F = 2.08, p = 0.001). Conclusions The results suggest that the seasonality of the semiarid is an important factor in the temporal dynamics of the limnological variables, while the aquatic macrophytes play an important role in the spatial distribution of the microcrustacean assembly.

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Temporal-spatial Distribution Characteristics of Air Pollutants in Chengdu Economic Region, China

E3S Web of Conferences ◽

10.1051/e3sconf/201911804027 ◽

2019 ◽

Vol 118 ◽

pp. 04027

Author(s):

Hongjin Tong ◽

Sha Liu ◽

Ruixue Liao ◽

Xiaomei Wei ◽

Kangli Che ◽

...

Keyword(s):

Spatial Distribution ◽

Temporal Variation ◽

Air Pollutants ◽

Interpolation Method ◽

Central Area ◽

Average Concentration ◽

Distribution Characteristics ◽

Economic Region ◽

Spatial Distribution Characteristics ◽

Variation Characteristics

The previous characteristics researches of air pollution were almost based on data from national environmental monitoring stations in 2015. The temporal variation curves of air pollutants and the ArcGIS grid interpolation method were used to analyze the spatial-temporal variation of air pollutants in five cities of Chengdu economic region. In 2015, the monthly change trends of PM2.5, PM10, CO, NO2 and NO of air pollutants in Chengdu economic region were basically the same. The maximum monthly average concentration was in January or December, and the minimum was in May to September. The temporal variation of SO2 was characterized by little fluctuation of monthly concentration. The temporal variation characteristics of O3 were opposite to other pollutants. The spatial distribution of PM10 and PM2.5 was characterized by the largest concentration in Chengdu and the southwest of Meishan, in which they were mainly concentrated in the central area of Chengdu in winter. The average concentration of CO in Chengdu was the largest, followed by Deyang and Mianyang, and Meishan and Ziyang was the smallest. The concentrations of NO2 and NO in Chengdu were the largest, while those in Ziyang were the smallest. The spatial distribution characteristics of O3 were different from other pollutants. The areas with the largest concentration of O3 were Ziyang and a small part of west in Chengdu. The spatial distribution of SO2 was characterized by the largest concentration of SO2 in Ziyang, the lowest concentration in Mianyang and Deyang.

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