scholarly journals Spatial dynamics of land cover in the Sdamas region (Tiaret, Algeria)

2018 ◽  
Vol 27 (1) ◽  
pp. 12-19
Author(s):  
Mohamed Azzaoui ◽  
Benchohra Maamar ◽  
Leila Soudani ◽  
Belgacem Nouar ◽  
Mohamed Berreyah ◽  
...  
Keyword(s):  
Land Cover ◽  
Temporal Dynamics ◽  
Spatial Dynamics ◽  
Ground Level ◽  
Human Action ◽  
Mineral Surfaces ◽  
Factors Affecting ◽  
Spatial And Temporal Dynamics ◽  
Landsat Satellite ◽  
Bare Soils

The Sdamas massif to which our contribution relates is located in West Algeria, it is an integral part of the Tiaret mountains. The aim of our study is to analyze the land cover of the Sdamas region over a 43-year interval grouped into 9 thematic classes: mineral surfaces (urban planning), wetland, vegetation, bare soils and fallow etc. The spatial and temporal dynamics of land use require regular monitoring of vegetation cover from remote sensing imagery. It is for this reason that we relied on field data to perform the diachronic analysis with three well-defined scenes 1972, 1998 and 2015, using Landsat satellite images (MSS, TM and ETM +). The analysis of these maps covering the same region shows the different changes that have taken place at ground level. We found that our natural plant space has undergone a strong degradation, disruption and regression because of different human activities, namely: overgrazing, clearing, fires, urbanization, (there has been a remarkable increase in the population of the communes of the study area). Inadequate and ineffective forestry interventionsand work, and lack of sustained protection are reasons of these processes. Factors affecting the forest ecosystem are bioclimate and human action. Indeed, the bioclimate, through atmospheric drought, is the main factor governing the diversity of these formations of the Sdamas mountains.

scholarly journals Modelling and  assessing driving factors of the spatial and temporal dynamics of the sand  dunes in the district of Errachidia, Morocco

2021 ◽  
Author(s):  
Tudal SINSIN ◽  
Fouad MOUNIR ◽  
Ahmed El ABOUDI
Keyword(s):  
Sand Dune ◽  
Temporal Dynamics ◽  
Moving Average ◽  
Sand Dunes ◽  
Ecological Factors ◽  
Temperature And Precipitation ◽  
Spatial And Temporal Dynamics ◽  
Combined Action ◽  
Landsat Satellite ◽  
Dune Dynamics

The desertification affects more than 250,000 ha in the district of Errachidia and results in the expansion of desert landscapes such as the Regs, Hamadas and the Dunes. The latter is a big concern in the district since it is the source of siltation, which threatens dwellings, cultivated lands and water bodies. It is of paramount importance to understand the causes and consequences of silting to develop strategies to combat it. Thus, first, we analysed the spatial and temporal dynamics of sand dunes until 2069 by applying the Seasonal Autoregressive Integrated Moving-Average (SARIMA) model on a time series of sand dune areas. These areas were calculated annually from 1987 to 2019 by computing the sand cover index (SCI) on Landsat satellite images. Furthermore, we evaluated the influence of different natural and human factors such as temperature, precipitation, wind, vegetation, and population growth, on sand dune dynamics using Spearman’s correlation test. The results indicated that the area of sand dunes will increase by 1.7% per year between 2019 and 2069 in the district of Errachidia. This increase would be mainly caused by the combined action of ecological factors, which vary from year to year. In general, temperature and precipitation act indirectly on wind and vegetation to influence the dynamics of sand dunes in hyper-arid areas where the soil is bare or poorly covered with vegetation, where precipitation is low and where temperature is high.

scholarly journals Methodological Proposal for the Study of Temporal and Spatial Dynamics during the Late Period between the Middle Ebro and the Pyrenees

Information ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 366 ◽  
Author(s):  
Leticia Tobalina Pulido
Keyword(s):  
Spatial Databases ◽  
Temporal Dynamics ◽  
Methodological Approach ◽  
Spatial Dynamics ◽  
Descriptive Statistics ◽  
Late Period ◽  
Rural Settlements ◽  
Spatial And Temporal Dynamics ◽  
Temporal And Spatial ◽  
Space Occupation

The article I present here deals with the methodological approach carried out in my PhD in which I analyzed the spatial and temporal dynamics of late rural settlements during five centuries in the southern Pyrenees area, using geographic information systems, spatial databases, and descriptive statistics to establish models of space occupation and try to determine how these vary over the different centuries.

scholarly journals Land use and land cover dynamics in Leiria City: relation between peri-urbanization processes and hydro-geomorphologic disasters

2021 ◽  
Author(s):  
José Leandro Barros ◽  
Alexandre Oliveira Tavares ◽  
Pedro Pinto Santos
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Temporal Dynamics ◽  
Historical Record ◽  
Spatial And Temporal Dynamics ◽  
Land Cover Dynamics ◽  
Central Portugal ◽  
Geomorphological Processes ◽  
Agricultural Areas ◽  
The City

AbstractThe objective of the present study is to evaluate the relation between the spatial and temporal dynamics of Land Use and Land Cover (LULC) and the hydro-geomorphological processes and their impacts. The study area is the city of Leiria, in central Portugal, within the period 1958–2018 based on the historical record of floods and landslides disasters. The LULC analysis shows an accentuated increase in the artificial areas and a continuous decrease in the agricultural areas. With regard to hydro-geomorphologic disaster occurrences, a total of 124 occurrences were identified, having caused a set of impacts. The obtained results allow one to characterize the artificialization process, its intensity and territorial dispersion, as a consequence of urban sprawl and peri-urbanization, along with its consequences in exposure to hydro-geomorphological processes. The analysis concludes that changing the risk drivers resulted in an increase in frequency and spatial dispersion of hydro-geomorphologic disasters over the analysed period.

Spatial Processes and the Duality of Church and Faith: A Simmelian Perspective on U.S. Denominational Growth, 1900–1930

1997 ◽  
Vol 40 (4) ◽  
pp. 557-580 ◽  
Author(s):  
Judith R. Blau ◽  
Kent Redding ◽  
Walter R. Davis ◽  
Kenneth C. Land
Keyword(s):  
Growth Rates ◽  
Temporal Dynamics ◽  
Spatial Dynamics ◽  
Political Movements ◽  
Competitive Markets ◽  
Spatial Processes ◽  
Religious Groups ◽  
Spatial And Temporal Dynamics ◽  
Social Associations

With information on all U.S. denominations of nontrivial sizes, this paper examines various spatial and temporal prcesses underlying religious expansion between 1900 and 1930. Simmel's provocative and complex essay, “Soziologie des Raumes” (1903) poses the central paradox that religion is both faith—cultural constellations of beliefs—and church—social associations that are spatially situated. This distinction helps to clarify differences among denominations with regard to the extent to which they exert strong demands on their members, and leads to predictions about variation in denominational growth rates, in spatial dynamics, and in the extent to which denominations accommodate to contextual heterodoxy (diversity) or not. In these terms, we re-examine the debate about whether adherence rates increase in competitive markets (under conditions of diversity) or under monopoly conditions (under conditions of little diversity). We finally suggest that Simmel's theoretical emphasis on spatial and temporal dynamics has relevance for understanding the nature of mobilization efforts of various kinds, not only by religious groups, but also by those that organize social and political movements

scholarly journals Identifying the spatial and temporal dynamics of molecularly-distinct glioblastoma sub-populations

2020 ◽  
Author(s):  
Bethan Morris ◽  
Lee Curtin ◽  
Andrea Hawkins-Daarud ◽  
Matthew E. Hubbard ◽  
Ruman Rahman ◽  
...  
Keyword(s):  
Targeted Therapies ◽  
Temporal Dynamics ◽  
Mechanistic Model ◽  
Factors Affecting ◽  
Primary Brain Tumours ◽  
Spatial And Temporal Dynamics ◽  
Multiple Biopsies ◽  
Study Population ◽  
Clinical Trial Results ◽  
Insight Into

AbstractGlioblastomas (GBMs) are the most aggressive primary brain tumours and have no known cure. Each individual tumour comprises multiple sub-populations of genetically-distinct cells that may respond differently to targeted therapies and may contribute to disappointing clinical trial results. Image-localized biopsy techniques allow multiple biopsies to be taken during surgery and provide information that identifies regions where particular sub-populations occur within an individual GBM, thus providing insight into their regional genetic variability. These sub-populations may also interact with one another through a competitive or cooperative nature; it is important to ascertain the nature of these interactions, as they may have implications for responses to targeted therapies. We combine genetic information from biopsies with a mechanistic model of interacting GBM sub-populations to characterise the nature of interactions between two commonly occurring GBM sub-populations, those with EGFR and PDGFRA genes amplified. We study population levels found across image-localized biopsy data from a cohort of 25 patients and compare this to model outputs under competitive, cooperative and neutral interaction assumptions. We explore other factors affecting the observed simulated sub-populations, such as selection advantages and phylogenetic ordering of mutations, which may also contribute to the levels of EGFR and PDGFRA amplified populations observed in biopsy data.

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