Wyniki wyszukiwania - BazTech

1

Spatio-temporal dynamics of vegetation cover in North-West Algeria using remote sensing data

Tayeb Tayeb Si, Kheloufi Benabdeli

Polish Cartographical Review

|

2019

|

Vol. 51, No. 3

117--127

EN

Land cover change is the result of complex interactions between social and environmental systems which change over time. While climatic and biophysics phenomena were for a long time the principal factor of land transformations, human activities are today the origin of the major part of land transformation which affects natural ecosystems. Quantification of natural and anthropogenic impacts on vegetation cover is often hampered by logistical issues, including (1) the difficulty of systematically monitoring the effects over large areas and (2) the lack of comparison sites needed to evaluate the effect of the factors. The effective procedure for measuring the degree of environmental change due to natural factors and human activities is the multitemporal study of vegetation cover. For this purpose, the aim of this work is the analysis of the evolution of land cover using remote sensing techniques, in order to better understand the respective role of natural and anthropogenic factors controlling this evolution. A spatio-temporal land cover dynamics study on a regional scale in Oranie, using Landsat data for two periods (1984–2000) and (2000–2011) was conducted. The images of the vegetation index were classified into three classes based on Normalized Difference Vegetation Index (NDVI) values and analysed using image difference approach. The result shows that the vegetation cover was changed. An intensive regression of the woody vegetation and forest land resulted in -22.5% of the area being lost between 1984 and 2000, 1,271 km2 was converted into scrub formations and 306 km2 into bare soil. On the other hand, this class increased by around 45% between 2000 and 2011, these evolutions resulting from the development of scrub groups with an area of 1,875.7 km2.

2

Morphology and Dynamics of the Baltic Sea Shore within Kaliningrad Oblast (Overview)

Babakov A.

Archives of Hydro-Engineering and Environmental Mechanics

|

2018

|

Vol. 65, nr 3

177--202

EN

A review of morphological and morphodynamic studies of the coast of the Kaliningrad oblast has been carried out for half a century. The studies include monitoring measurements by the Atlantic Branch of the Shirshov Institute of Oceanology of the Russian Academy of Sciences (AB IO RAS) with the participation of the state institute Baltberegozashchita (BBZ), as well as pre-war studies and cartographic analyses of long-term coastline migration carried out by the private company Baltic Aerogeodetic Enterprise (BaltAGE). It shows the spatial alternation of abrasive and accumulative areas, as well as frequent changes in beach width and height within the same morphological coast type. A change in the development trend of particular coast sections from year to year was noted. The significant influence of anthropogenic factors on the coastal development was emphasized, including changes in the direction of coastal retreat/advance along an extensive coastal stretch. Comparison of the interannual and nearly century-old dynamics of the coast revealed noticeable differences between them, with opposite trends in several large-scale coast sections.

3

A new procedure for the design of iterative learning controllers using a 2D systems formulation of processes with uncertain spatio-temporal dynamics

Cichy B., Gałkowski K., Dąbkowski K., Aschemann H., Rauh A.

Control and Cybernetics

|

2013

|

Vol. 42, no. 1

9--26

EN

Iterative Learning Control (ILC) is well established in control of linear and nonlinear dynamic systems, both as to underlying theory and experimental validation. This approach specifically aims at applications with the same operation repeated over finite time intervals and reset taking place between subsequent executions (the trials). The main principle behind ILC is to suitably use information from previous trials in selection of the input signal in the current trial with the objective of performance improvement from trial to trial. In this paper, new computationally efficient results are presented for an extension of the ILC approach to the uncertain 2D systems that arise from time and space discretization of partial differential equations. This type of application implies the need to use a spatio–temporal setting for the analysis of the control procedure. The resulting control laws can be computed using Linear Matrix Inequalities (LMIs). An illustrative example is provided.