Spatial-temporal Distribution Pattern Research Articles

Electromagnetic studies of Zvizdal-Zaliska and Brusyliv fault zones of the Ukrainian shield

Spatial-temporal distribution pattern of geomagnetic variations and electric field in the western part of the Ukrainian shield has been obtained as a result of experimental studies carried out by the methods of deep magnetotelluric sounding and magnetovariational profiling in 2018 along two profiles (15 points). It makes possible to estimate the value of electroconductivity and geoelectric structure of the section along the vertical and horizontal directions. Processing has been conducted with the help of modern software system PRC-MTMV that guarantees joint noise immunity of evaluation of impedance and induction parameters of synchronous МТ/МВ-records. Tipper appraisals have been obtained for the periods of geomagnetic variations from 50 to 3400 s, the curves of apparent resistance and phases of impedance from 20 to 10000 s. The principal result of high quality interpretation of geoelectric studies is revealing of high electro-conductivity anomalies (4 surface ones, 1 subsurface) in the Earth crust with complex system of faults in jointing zone of the Podolia and Rossinsky megablocks. Anomalies are characterized by different electroconductivity, the depth of occurrence and shape. Appraisals obtained with different approaches to formal interpretation of magnetotelluric sounding agree with regional three-dimensional geoelectric model of the western part of the Ukrainian shield and add to the concept on debatable deep structure. Surface anomalies of electroconductivity have been discovered: 1) in the central part of Zvizdal-Zalessky fault zone, 2) between the Pogrebynsky and the Kocherov faults, 3) along the Velykoerchyk and 4) Ulashev faults. Their nature is explained by heightened content of graphite and by ore formation confined to tectono-metasomatic zones. Deep anomaly of electroconductivity has been allocated with its surface projection spatially coinsiding with the area of cross-section of the Brussilov and the Nemyrov fault zones (and mineraginetic zones of the same name). Its upper edge deepens eastward from Zvizdal-Zalessky fault zone. High electroconductivity anomalies are spatially attached to tectonic fault zones and the zones of metasomatic alterations. Their territorial arrangement corresponds to metallogenic ore zones. Therefore they can be used as geoelectric criteria for the search of ore manifestations.

Cultural evolution and spatial-temporal distribution of archaeological sites from 9.5–2.3 ka BP in the Yan-Liao region, China

With basic information from 8353 archaeological sites, this study describes a holistic spatial-temporal distribution pattern of archaeological sites of the prehistoric culture sequence from 9.5 ka BP (ka BP = thousands of years before 0 BP, where “0 BP” is defined as the year AD 1950) to 2.3 ka BP in the region that extends from the Yanshan Mountains to the Liaohe River Plain (i.e., the Yan-Liao region) in northern China. Based on spatial statistics analysis–including the spatial density of the sites and Geographic Information System nearest- neighbour analysis, combined with a review of environmental and climatic data–this paper analyses cultural evolution, the spatial-temporal features of the archaeological sites and human activities against the backdrop of climatic and environmental changes in this region. The results reveal that prehistoric cultural evolution in the Yan-Liao region is extensively influenced by climatic and environmental changes. The Xinglongwa, Zhaobaogou and Fuhe cultures, which primarily developed during a habitable period from 8.5 ka BP to 6.0 ka BP with strong summer monsoons, have similar maximum density values, spatial patterns and subsistence strategies dominated by hunting-gathering. Significant changes occurred in the Hongshan and Lower Xiajiadian cultures, with a significant increase in numbers and densities of sites and a slump in average nearest-neighbour ratio when the environment began to deteriorate starting in 6.0 ka BP. Additionally, with the onset of a weak summer monsoon and the predominance of primitive agriculture, sites of these two cultures present a different type of concentric circle-shaped pattern in space. As the environment continuously deteriorated with increasing aridity and the spread of steppe, more sites were distributed towards the south, and primitive agriculture was replaced by livestock husbandry in the Upper Xiajiadian culture. The most densely populated areas of the studied cultures are centralized within a limited area. The Laohahe River and Jiaolaihe River basins formed the core area in which most archaeological sites were distributed during the strong summer monsoon period and the first few thousand years of the weak summer monsoon period.

Multiple spatial–temporal scale change patterns of rainfall erosivity in China over past 58 years based on gravity centre model

The rainfall erosivity in China have shown different change characteristics and patterns at different spatial–temporal scales. In this article, we introduced a gravity centre model for use in studying and analyzing the spatial–temporal distribution patterns of rainfall erosivity in China in the past 58 years combined with traditional geostatistical analysis methods at different spatial–temporal scales. During 1961–2018, rainfall erosivity in China showed a decreasing trend from southeast to northwest in spatial distribution. Moreover, the spatial distribution patterns of the annual average rainfall erosivity had been negatively affected by altitude. In terms of interannual variability, rainfall erosivity had shown a fluctuating upward trend in the past 58 years, with a steep upward slope in 1982 and a steep downward slope in 1990. In the past 58 years, the gravity centre of rainfall erosivity in China had moved southeastward, which indicated that the increment and increasing rate of rainfall erosivity in eastern and southern China were greater than those in western and northern China. These results could provide important data to support decisions regarding the prevention and control of soil erosion at regional and national scales.

Temporal and Spatial Distribution Pattern of Population at the South End of Hu Line in Recent 25 Years

The southern end of Hu Line mainly involves Sichuan and Yunnan provinces. In this paper, the spatial-temporal distribution pattern of population is analyzed by Standard Deviation Ellipse (SDE) and Exploratory Spatial Data Analysis (ESDA). The influence of human geography, natural geography and soil environmental factors on the spatial distribution of population and interactive interpretation are quantitatively calculated based on Geo-detector. The results show that: (1) the spatial distribution pattern of the population at the southern end of Hu Line is northeast-southwest. The spatial differences between the two sides are significant, the standard deviation ellipse turns weaker gradually, and the population distribution in southwestern China is balanced year by year. (2) The population concentration of the southern end of the Hu Line has been decreasing with the “U” type. Spatial aggregation occurs in high-density counties and surrounding high-density counties. The inaccessible regions appear in contiguous on the west side of the Hu Line. In less counties, there is a clear difference between the surrounding counties and the self, and the spatial distribution of the population tends to be balanced. (3) The dominant factors affecting the spatial distribution of population over the years are GDP density, nighttime lighting, road nuclear density, landforms, farmland production potential and elevation. (4) GDP density, road nuclear density, NDVI and NPP have a good interaction enhancement effect on population distribution. The first geographical intrinsic and the second geographic intrinsic evaluation index have the highest priority. The two-factor action intensity is greater than the single-factor action intensity, and the interaction type tends to be dominated by nonlinear enhancement. The spatial distribution of the population in the southern end of the Hu Line is mainly balanced by economic development and road construction. Night lighting, landform, farmland production potential, elevation, NDVI and NPP are potential factors for optimizing the population distribution at the southern end of the Hu Line.

Influence of environmental factors on spatial–temporal distribution patterns of dinoflagellate cyst communities in the South China Sea

The spatial–temporal distribution of dinoflagellate cyst (i.e., dinocyst) communities is crucial for understanding the detailed mechanisms of recurrence and spread of harmful algae blooms in marine ecosystems. Here, we employed the newly developed high-throughput sequencing-based metabarcoding to characterize dinocyst communities collected from the South China Sea. Further, we clarified the spatial–temporal distribution patterns and analyzed the correlation between environmental factors and the observed patterns to investigate how they are influenced by environmental factors. Our results showed that the spatial distribution of dinocyst species richness and abundance varied greatly between sampling sites in different seasons. Both redundancy and Pearson analyses showed that the chemical oxygen femand, which could explained 35.0% of the total community variation, had positive correlations with heterotrophic dinocyst richness and negative correlations with autotrophic dinocysts richness. We did not find significant correlations between heavy metals and any features of dinocyst species richness. No environmental factor showed significant effects on dinocyst abundance based on forward selection after excluding colinearity; however, Pearson’s correlation analyses showed that the abundance of heterotrophic dinocysts presented a significant positive correlation with Mn (P < 0.05). Our results showed that the influence of environmental factors on spatial–temporal distribution of dinocyst species could be region- and/or environment-specific. Consequently, we suggest that detailed investigations should be performed to clarify the influence of varied environmental factors on dinocyst community characteristics in different regions and/or seasons.

Research on the Spatial-Temporal Distribution Pattern of the Network Attention of Fog and Haze in China

Understanding the spatial-temporal distribution pattern of fog and haze is the base to deal with them by adjusting measures to local conditions. Taking 31 provinces in China mainland as the research areas, this paper collected data from Baidu index on the network attention of fog and haze in relevant areas from 2011 to 2016, and conducted an analysis of their spatial-temporal distribution pattern by using autocorrelation analysis. The results show that the network attention of fog and haze has an overall spatial distribution pattern of “higher in the eastern and central, lower in the western China”. There are regional differences in different provinces in terms of network attention. Network attention of fog and haze indicates an obvious geographical agglomeration phenomenon, which is a gradual enlargement of the agglomeration area of higher value with a slight shrinking of those lower value agglomeration areas.

Characterizing fractional vegetation cover and land surface temperature based on sub-pixel fractional impervious surfaces from Landsat TM/ETM+

Estimating the distribution of impervious surfaces and vegetation is important for analysing urban landscapes and their thermal environment. The application of a crisp classification of land-cover types to analyse urban landscape patterns and land surface temperature (LST) in detail presents a challenge, mainly due to the complex characteristics of urban landscapes. In this article, sub-pixel percentage impervious surface areas (ISAs) and fractional vegetation cover (FVC) were extracted from bitemporal Thematic Mapper/Enhanced Thematic Mapper Plus (TM/ETM+) data by linear spectral mixture analysis (LSMA). Their accuracy was assessed with proportional area estimates of the impervious surface and vegetation extracted from high-resolution data. A range approach was used to classify percentage ISA into different categories by setting thresholds of fractional values and these were compared for their LST patterns. For each ISA category, FVC, LST, and percentage ISA were used to quantify the urban thermal characteristics of different developed areas in the city of Fuzhou, China. Urban LST scenarios in different seasons and ISA categories were simulated to analyse the seasonal variations and the impact of urban landscape pattern changes on the thermal environment. The results show that FVC and LST based on percentage ISA can be used to quantitatively analyse the process of urban expansion and its impacts on the spatial–temporal distribution patterns of the urban thermal environment. This analysis can support urban planning by providing knowledge on the climate adaptation potential of specific urban spatial patterns.

P1-127 Spatial and temporal dynamics of dengue fever cases in Araraquara city, Brazil

BackgroundDengue fever represents a serious public health issue in Brazil. Araraquara is a city, in state of São Paulo that has been having serious outbreaks of dengue fever in the...

Anthropogenic nexus on organochlorine pesticide pollution: a case study with Tamiraparani river basin, South India

The levels of 17 organochlorine pesticides residues (OCPs) in surface water and sediments from Tamiraparani river basin, South India were investigated to evaluate their potential pollution and risk impacts. A total of 96 surface water and sediment samples at 12 sampling stations were collected along the river in four seasons during 2008-2009. The ΣOCP concentrations in surface water and sediments were in the range of 0.1 to 79.9 ng l(-1) and 0.12 to 3,938.7 ng g(-1) dry weight (dw), respectively. Among the OCPs, the levels of dichlorodiphenyltrichloroethanes (DDTs), aldrin, dieldrin, cis-chlordane, trans-chlordane, and mirex were dominant in the sediments. The dominant OCPs in water samples are heptachlor, o,p'-DDE, dieldrin, o,p'-DDD, and mirex, which show different source of contamination pattern among sampling seasons. The distribution pattern of DDTs, hexachlorocyclohexane, and other OCPs in the present study shows heterogenic nature of nonpoint source of pollution. Notable contamination of water and sediment sample that was observed in upstream (S2) 58 ng l(-1) and downstream (S11) 1,693 ng g(-1) dw explains agricultural and municipal outfalls, whereas frequent damming effect reduces the concentration level in the midstream. The overall spatial-temporal distribution pattern of ΣOCP residues are illustrated by GIS package.

Sediment retention at the Changjiang sub-aqueous delta over a 57 year period, in response to catchment changes

The growth of a river delta system is controlled mainly by fluvial sediment discharge and sediment retention in the deltaic areas. In the present study, we attempt to define a sediment retention index, R, and its relation to the deposition rate of the delta. Based upon two assumptions that the amount of the sediment that escapes from the deltaic areas, Q E , is stationary with minor fluctuations, and that there is a linear relationship between the deposition rate averaged over the sub-aqueous delta ( D av ) and the deposition rate at accretion sites within the delta ( D R ), the changes in the accretion/erosion patterns of the Changjiang sub-aqueous delta during the period of 1951–2007, in response to river sediment discharge changes, are analyzed. The results show that the sediment retention index can be related to the deposition rate of the sub-aqueous delta; the spatial-temporal distribution pattern of the deposition rate reveals the behaviour of sediment retention of a delta system. For the Changjiang sub-aqueous delta, fluvial sediment discharge data, together with Pb-210 based deposition rates, provide useful information on sediment retention. Changes in the sediment retention index and the accretion/erosion patterns of the sub-aqueous delta have taken place in response to river input changes. In order to improve our understanding of the processes associated with estuarine sediment retention, sediment cores with sufficient spatial coverage may be collected and analyzed to establish accurate Q E – R and D av – D R relationships. In combination with numerical modeling of sediment transport, these relationships form a basis for the analysis of sediment retention mechanisms.

Identification of the spatial-temporal distribution pattern of swordfish (Xiphias gladius) in the southeastern Pacific

Identification of the spatial-temporal distribution pattern of swordfish (Xiphias gladius) in the southeastern Pacific

Identification of the spatial-temporal distribution pattern of swordfish (Xiphias gladius) in the southeastern Pacific

The pattern of the spatial-temporal distribution of the fishing yields (catch rates) of swordfish (Xiphias gladius) from the Chilean industrial longline fleet it was determined using generalized additives models, autocorrelation analysis and Fourier spectral analysis. The basic information came from fishing log- book recorded by scientific observers between January 2001 and December 2005. The generalized additives models included five physical variables (latitude, longitude, date, lunar index and sea surface temperature (SST)), which affect the availability and vulnerability of swordfish, and two operational variables (length of the vessel and type of longline), which are directly associated with the effectiveness of the fishing system. The non-linear effects were established significantly (p < 0.01) for each of the independent variables. There was a typical annual cycle in the catch rates, with high values from March to July/August, and displacement of the fishing operation northward from the 38° to 32°S, in a SST range of 17° to 19°C. Subsequently, catch rates decrease in a northerly direction from 32°S in SST higher than 20°C. This spatial-temporal pattern was determinates with a high square coherency (79%) in the time series of nominal catch rates and latitudinal component analyzed in the Fourier spectral analysis. It also established for the time series of swordfish nomi- nal catch rates, low-frequency fluctuations with periods of 28, 38 and 59 days. This intraseasonal variability in swordfish catch rates coincides with changes in mesoscale oceanographic conditions in the area where the fishery is developed off the coast of Chile.

Priorities for the conservation of avian biodiversity in China based on the distribution patterns of endemic bird genera.

Ten endemic Chinese bird genera are currently recognized: Nipponia, Tetraophasis, Chrysolophus, Crossoptilon, Ithaginis, Pseudopodoces, Rhopophilus, Kozlowia, Urocynchramus and Latoucheornis. Of these genera, Nipponia, Ithaginis, Pseudopodoces, Rhopophilus, Kozlowia, Urocynchramus and Latoucheornis are monotypic, while Tetraophasis, Chrysolophus and Crossoptilon are polytypic. In this paper, we first set up a database of the geographic distribution and suitable habitat requirements for each species of these endemic genera. Secondly we produced a modified habitat-based prediction of their distribution using GIS (ArcView 3.1) software overlap analysis. We then explored the spatial–temporal distribution patterns of different genera. By comparing the richness of the endemic genera in distributed areas, we identified centers of endemic avian biodiversity. These are: the northern and eastern Hengduanshan Mountains, and the Qinling, Dabashan and Minshan Mountain regions. Finally, we identified conservation ‘hotspots’ with a higher priority based on these centers. These results may provide a valuable tool for identifying and conserving areas with high endemic biodiversity and methods for researching the biogeography of endemic genera, the evolutionary history of fauna and species differentiation.

Immunocytochemical localization of the heparin-binding growth-associated molecule (HB-GAM) in the developing and adult rat cerebellar cortex

The heparin-binding, growth-associated molecule (HB-GAM) is a developmentally regulated protein that belongs to a new family of heparin-binding molecules, not related to the fibroblast growth factors (FGFs), with putative functions during cell growth and differentiation. In order to further study the functional role of HB-GAM we have used a polyclonal antiserum, raised against the purified protein to localize HB-GAM in the developing and adult rat cerebellar cortex. During postnatal development HB-GAM-like immunoreactivity (IR) was found to be present in all layers of the cerebellar cortex. IR was mainly associated with processes or extracellular structures but not with cell bodies. Throughout all the stages examined the molecular layer was clearly labeled, whereas staining in the internal granular layer was diffuse. IR in the external granular layer on postnatal day 1 and 8 was found to be associated with radially oriented fibres connecting the internal granular layer with the pial surface of the cerebellum. The intensity of this staining seemed to increase from day 1 to 8. Staining of corresponding areas with an antiserum against the glial fibrillary acidic protein (GFAP) suggested that the HB-GAM antiserum in the developing cerebellar cortex labers Bergmann glia fibres of Golgi epithelial cells. Because of the diffuse staining of the molecular layer in the adult rat it was not possible to distinguish whether radial fibres in the adult contained any HB-GAM IR. Golgi epithelial cells are considered as crucial for the migration of granular cells during the differentiation of the cerebellar cortex. We therefore speculate that the association of HB-GAM-like IR may be of functional relevance. The fact that molecules, such as tenascin, known to be involved in morphogenetic events show a similar spatial temporal distribution pattern further underscores this hypothesis. HB-GAM, which possesses a classical signal sequence, might be released in the extracellular space and could mediate adhesion phenomena by binding to heparin-like molecules associated with the neuronal membrane. Therefore, it will be important to investigate whether specific antibodies against HB-GAM are able to interfere with normal cerebellar development in vitro and in vivo.