Spatial distribution of the extreme hydrological events in Xinjiang, north-west of China

2013 ◽  
Vol 67 (2) ◽  
pp. 483-495 ◽  
Author(s):  
Guili Sun ◽  
Yaning Chen ◽  
Weihong Li ◽  
Cunde Pan ◽  
Jiang Li ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
North West ◽  
Extreme Hydrological Events

scholarly journals Spatial Distribution and Evaluation of Arsenic and Zinc Content in the Soil of a Karst Landscape

2021 ◽  
Vol 13 (12) ◽  
pp. 6976
Author(s):  
Dimitrios E. Alexakis ◽  
George D. Bathrellos ◽  
Hariklia D. Skilodimou ◽  
Dimitra E. Gamvroula
Keyword(s):  
Land Use ◽  
Spatial Distribution ◽  
Land Use Planning ◽  
Urban Soil ◽  
Agricultural Soil ◽  
Agricultural Land ◽  
Land Evaluation ◽  
Agricultural Activity ◽  
North West ◽  
Total Study Area

Karst features such as polje are highly vulnerable to natural and anthropogenic pollution. The main objectives of this study were to investigate the soil quality in the Ioannina polje (north-west Greece) concerning arsenic (As) and zinc (Zn), and delineate their origin as well as compare the As and Zn content in soil with criteria recorded in the literature. For this purpose, the geomorphological settings, the land use, and the soil physicochemical properties were mapped and evaluated, including soil texture and concentrations of aqua-regia extractable As and Zn. The concentration of elements was spatially correlated with the land use and the geology of the study area, while screening values were applied to assess land suitability. The results reveal that 72% of the total study area has a very gentle slope. This relief favors urban and agricultural activity. Thus, the urban and agricultural land used cover 92% of the total area. The spatial distribution for As and Zn in the soil of the study area is located on very gentle slopes and is strongly correlated with the geological parent materials and human-induced contamination sources. Arsenic and Zn can be considered enriched in the soil of the area studied. The median topsoil contents (in mg kg−1) for As (agricultural soil 16.0; urban soil 17.8) and Zn (agricultural soil 92.0; urban soil 95.0) are higher compared to the corresponding median values of European topsoils. Land evaluation suitability concerning criteria given from the literature is discussed. The proposed work may be helpful in the project of land use planning and the protection of the natural environment.

Diffuse He degassing monitoring of the Tenerife North-western Rift Zone (NWRZ) volcano, Canary Islands

2020 ◽  
Author(s):  
Guillermo Recio ◽  
Eleanor Dunn ◽  
Yasmin McInally ◽  
Nemesio M. Pérez ◽  
Cecilia Amonte ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Rift Zone ◽  
Soil Gas ◽  
Sequential Gaussian Simulation ◽  
Volcanic Complex ◽  
Concentration Data ◽  
Entire Area ◽  
North West ◽  
Geochemical Properties ◽  
Helium Emission

<p>Tenerife (2034 km<sup>2</sup>), the largest island of the Canarian archipelago, is characterized by three volcanic rifts oriented NW-SE, NE-SW and N-S with a central volcanic complex, Las Cañadas Caldera, hosting Teide-Pico Viejo volcanoes. The North West volcanic Rift Zone (NWRZ, 72 km<sup>2</sup>) of Tenerife is one of the youngest and most active volcanic systems of the island, where two historical eruptions have occurred: Arenas Negras in 1706 and Chinyero in 1909. Diffuse degassing studies has become an important volcanic surveillance tool at those volcanic areas where visible manifestations of volcanic gases are absent, as in the case of NWRZ. Mapping soil gas emission along volcanic structures can provide a better understanding of the processes occurring at depth and allows monitoring the spatial distribution, magnitude and temporal evolution of the surface gas emissions. The geochemical properties of He, minimize the interaction of this noble gas on its movement toward the earth’s surface, and make this gas an almost ideal geochemical indicator of changes occurring in the magmatic plumbing system of the volcano (Padrón et al., 2013, Geology 41(5):539–542). Since 2014, surface He emission surveys have been performed once a year as an additional geochemical tool to monitor the volcanic activity of NWRZ. At 345 sampling sites soil gas samples were collected at 40 cm depth and analyzed for He concentration within 24 hours by means of QMS, model Pfeiffer Omnistar 422. The soil helium concentration data were used to estimate the diffusive helium flux at each point, to construct spatial distribution maps by sequential Gaussian simulation and then to estimate the total helium emission in the NWRZ. Helium emission ranged between non-detected values up to 7.2 mgm<sup>-2</sup>d<sup>-1</sup>, and the emission rate of the entire area was in the range ~1 – 45 kg d<sup>-1</sup>. An increasing trend was observed in the period 2016-2018, showing a good temporal coincidence with a significant increase in seismic activity recorded in Tenerife. The promising results observed in the NWRZ and in other volcanic systems (Padrón et al., 2013) indicate that soil helium emission monitoring could be an excellent early warning geochemical precursory signal for future volcanic unrest.</p>

scholarly journals Time-clustering of wave storms in the Mediterranean Sea

2016 ◽  
Author(s):  
Giovanni Besio ◽  
Riccardo Briganti ◽  
Alessandro Romano ◽  
Lorenzo Mentaschi ◽  
Paolo De Girolamo
Keyword(s):  
Spatial Distribution ◽  
Mediterranean Sea ◽  
Time Scales ◽  
Horizontal Resolution ◽  
North West ◽  
Temporal Sampling ◽  
The North ◽  
Allan Factor ◽  
Long Time ◽  
The Mediterranean

Abstract. In this contribution we identify storm time-clustering in the Mediterranean Sea through the analysis of the spatial distribution of the Allan Factor. This parameter is evaluated from long time series of wave height provided by means of oceanographic buoy measurements and hindcast re-analysis spanning in the period 1979–2014 and characterized by a horizontal resolution of about 0.1 degree in longitude and latitude and a temporal sampling of one hour (Mentaschi et a., 2015). Results reveal clustering mainly for two distinct ranges of time scales. The first range of time scales (12 hrs to 50 days) is associated to sequences of storms generated by the persistence of the same meteorological system. The second range, associated to timescales beteween 50 and 100 days, reveals seasonal fluctuations. Transitional regimes are present at some locations in the basin. The spatial distribution of the Allan Factor reveals that the clustering at smaller time scales is present in the North-West of the Mediterranean, while clustering at larger scales is observed in the whole basin. This analysis is believed to be important to assess the local increased flood and coastal erosion risks due to storm clustering.

scholarly journals Geovisualization Techniques of Spatial Environmental Data Using Different Visualization Tools

2020 ◽  
Vol 10 (19) ◽  
pp. 6701
Author(s):  
Dániel Balla ◽  
Marianna Zichar ◽  
Róbert Tóth ◽  
Emőke Kiss ◽  
Gergő Karancsi ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Spatial Data ◽  
Spatial Databases ◽  
Spatial Information ◽  
Central Area ◽  
Environmental Data ◽  
Cognitive Approach ◽  
North West ◽  
Distribution Maps ◽  
Sewage System

The appearance of online map services and frameworks (e.g., KML, QGIS) has increased the possibilities to easily, quickly and—in many cases—cost-effectively publish spatial data stored in databases. The aim of this study is to present the geovisualization of spatial databases of a Hungarian settlement on the web, using the open source webGIS system and Google application programming interfaces (APIs). The interactive point and interpolated distribution maps available online provide a detailed picture of the level of contamination, the spatial distribution of the ground water supply of the investigated settlement, and the changes which have occurred following the establishment of the sewage system. In the case of PO43− we determined that in the year before the sewage system was constructed, most of the area of the settlement could be considered contaminated, with the highest level of contamination measured in the central area of the settlement. Five years after the construction of the sewage system, the ratio of the contaminated areas had significantly decreased. In the case of NO3− we found a high level of contamination before the construction of the sewage system with a concentration increase in a North–West direction. After the establishment of the sewage system, the increase in concentration was the most intense in the central parts of the settlement, while the characteristic spatial distribution could no longer be observed. The geovisualization techniques developed are able to provide information about the different spatial data for users in a visual way, and also help to understand better the spatial information using a cognitive approach. The advantage of interactive web maps created with the technologies applied over traditional static maps is a new approach, which allows the user to manipulate the temporal and spatial data directly in the most appropriate way.

Seasonal and spatial distribution of chaetognaths on the north-west continental shelf of the South China Sea

2014 ◽  
Vol 94 (4) ◽  
pp. 837-846 ◽  
Author(s):  
X. Wu ◽  
K. Li ◽  
L. Huang ◽  
J. Yin ◽  
Y. Tan
Keyword(s):  
Spatial Distribution ◽  
South China Sea ◽  
Continental Shelf ◽  
South China ◽  
The South China Sea ◽  
The South ◽  
North West ◽  
China Sea ◽  
The North ◽  
Region I

The seasonal variation and spatial distribution of chaetognaths were studied based on samples collected from July to August 2006 (summer), December 2006 to January 2007 (winter), and in April 2007 (spring) on the north-west continental shelf of the South China Sea. A total of 19 species of chaetognaths were identified. The average chaetognath abundances (mean ±SD) were 54.0 ± 44.5, 36.8 ±16.7 and 48.9 ± 95.5 ind. m−3 in summer, winter and spring, respectively. Flaccisagitta enflata and Serratosagitta pacifica were the dominant species during the whole sampling period, and F. enflata determined the spatial distribution of total chaetognath abundance. According to the topography and hydrological conditions, the survey area was divided into three sub-regions: inshore waters of the western Guangdong (Region I), inshore waters to the east of Hainan Island (Region II) and offshore waters from the western Guangdong to Hainan Island (Region III). The community structure and abundance distribution of chaetognaths varied significantly between the three sub-regions. The species richness was significantly different among the three sub-regions, with the lowest in Region I and the highest in Region III. The species richness was correlated positively with temperature and salinity. The abundance of chaetognaths was significantly higher in Region I than in both Regions II and III in summer and spring. The increasing food availability caused by the cold eddy, coastal upwelling and the western Guangdong coastal current was able support a greater abundance of chaetognaths during warm seasons on the north-west continental shelf of the South China Sea.

scholarly journals Prevalence and Spatial Distribution of Animal Brucellosis in Central Punjab, Pakistan

2020 ◽  
Vol 17 (18) ◽  
pp. 6903
Author(s):  
Usama Saeed ◽  
Shahzad Ali ◽  
Tooba Latif ◽  
Muhammad Rizwan ◽  
Attaullah ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Demographic Data ◽  
Control Measures ◽  
Western Region ◽  
The South ◽  
Serum Samples ◽  
North West ◽  
Control Programs ◽  
Quality Of Control ◽  
Surface Plot

Brucellosis is an important zoonotic disease of animals and humans caused by bacteria of the genus Brucella. Brucellae are Gram-negative intracellular bacteria which infect a wide variety of animals including goats, sheep, buffaloes, cows, pigs, and wildlife. The objectives of this study were to determine the seroprevalence and spatial distribution of brucellosis in Central Punjab, Pakistan. A total of 1083 blood samples of goats, sheep, buffaloes, and cows were collected from 38 villages of four districts (Kasur, Faisalabad, Lahore, and Okara) of Punjab, Pakistan, and screened for brucellosis by Rose Bengal Plate test (RBPT) and PCR confirmed. Epidemiological, demographic data and GPS coordinates for every sample were collected. By using interpolation of the Aeronautical Reconnaissance Coverage Geographic Information System (Arc GIS), a surface plot was generated applying inverse distance weight (IDW). It was found that 35 (3.23%) serum samples were positive for brucellosis. In eight (61.5%), six (75%), seven (87.5%), and eight (89%) villages, positive goats, sheep, buffaloes, and cattle were detected, respectively. In general, older animals are more often positive for brucellosis. In goats bucks were more often RBPT positive than females while in sheep, buffaloes, and cattle more females were positive. The spatial distribution of brucellosis shows that it is widely distributed in the western region of the study area in goats and in the South-West region in sheep. Similarly, for buffaloes it is restricted to the south-east and north-west regions, and in cattle brucellosis is present in western region of study area only. Reflected by this study, brucellosis poses a risk for livestock in developing countries due to lack of awareness by officials, owners, and consumers, and control measures are missing. A risk map of brucellosis was generated to develop effective strategies for awareness rising and to improve the quality of control programs in Pakistan.

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