Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 3

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
EN
Coastal zones, as highly dynamic and complex environments, have substantial ecological and territorial implications for both government authorities and coastal managers. This research study investigated the impacts of port construction on shoreline dynamics along the coastal region of Ksar Esghir, located on the northern coast of Morocco, over a 19-year period (2002–2021). This study aimed to characterize the evolution of the coastline using high-resolution satellite images in a geographic information system (GIS) environment. Coastline evolution was assessed using GIS tools, particularly the digital shoreline analysis system (DSAS). Statistical approaches were used to determine the net rates of shoreline change, namely the end point rate (EPR) and net shoreline movement (NSM). Three main sectors were defined for the study area: The Eddallya sector, the western sector of Ksar Esghir and the port sector. As a result, two distinct zones have been identified in the Eddallya sector. Zone I shows an average accretion of +1.46 m/year, while zone II shows an erosion of -0.80 m/year. Analysis of the western sector of Oued Ksar Sghir revealed both erosion and accretion sites. Furthermore, the port sector showed positive values for shoreline evolution, with an average of +9.44 m and a rate of +0.49 m/year, signifying significant shoreline expansion over the study period. These findings highlight the dynamic and highly complex processes involved in coastal development in the study area. The results suggest that sediment dynamics, tidal regimes and potential anthropogenic influences have a significant impact on shoreline evolution, especially where port construction is concerned. The outcomes of this study provide helpful information for better and sustainable coastal management along the coastal area of Ksar Sghir.
EN
Climate change poses a major challenge in terms of urban planning management for the sake of a sustainable future. It is affecting the hydrological cycle around the world, leading to extreme weather conditions. Floods rank as the most frequent and widespread disaster in the world, they adversely affect inhabitants in terms of property damage and threat to human safety (and lives, in the worst cases). Uncontrolled urban sprawl also exacerbates floods by expanding impervious surfaces and affecting flow paths. Other factors that trigger flooding (apart from the rainfall intensity) are human involvement in the main waterways, thereby significantly impacting the hydraulic flow characteristics, structural engineering breakdowns, compounded by potential deforestation. For the purpose of monitoring the aftermath of floods experienced by the cities of Casablanca and Tetouan (Morocco) respectively in January and March 2021 and estimating their damages, optical and radar satellite images derived from the Google Earth Engine (GEE) cloud platform were used along with the Geographic Information System (GIS). In this study, a novel technique for extracting flooded areas from high-resolution Synthetic Aperture Radar (SAR) time series images has been developed. A comparison was carried out subsequently between the time-series approach and other traditional approaches including radiometric thresholding method, spectral indices namely Normalized Difference Water Index (NDWI) and Modified Normalized Difference Water Index (MNDWI) as well as Flood Water Index (FWI). Based on the above approach, the water levels were estimated and the damages were assessed and mapped, notably the number of people exposed to flood hazard and the amount of built-up areas and cropland affected. The results demonstrated that Casablanca city has witnessed a higher flood level than Tetouan city, putting a large number of people at risk and affecting a significant area of land use. The findings can also provide local authorities with a comprehensive view of flooding and enable them to make decisions on preparedness, mitigation, and adaptation to flood-related disasters.
EN
Despite their highly recognized ecological values and ecosystem services, approved by the scientific community, wetlands are in perpetual degradation and their global spatial extension in significant regression. The conservation and sustainability of such ecosystems begins with their monitoring and delimitation. This study aims to develop an approach using open access remote sensing data to make this delineation. Applied to the coastal wetland complex of the lower Loukkos in the Mediterranean area, the methodology followed a two-step process. Firstly, it predicted the spaces favourable for water accumulation conditions, and secondly, it identified the presence of water and its response on the soil and vegetation. The approach was based on a theoretical modelling adopting the potential, existing, efficient wetland (PEEW) approach. The recordings from Sentinel sensors served as the basis for calculating indices Beven-Kirkby Index (BKI), Buffer zone Index (BZI), Normalized Difference Moisture Index (NDMI), Normalized Difference Vegetation Index (NDVI) and Modified Normalized water difference index (MNDWI) to pre-locate and model potential wetland areas (PW). Photo Interpretation was used to map the existing wetland areas (EW). The estimated area of wetlands in the lower Loukkos region is 379 km2 for potential areas identified from topographic data and the hydrographic network, 120 km2 for areas dominated by wetlands detected by remote sensing of water bodies , vegetation and soil moisture, and 33 km2 for natural wetlands identified by photo-interpretation. As a result, the area of current wetlands is only about 9.5% of their theoretical past extent. The validity of this method was confirmed through a comparison of the results with field investigations and hydromorphic traits in soil surveys, as well as external soil mapping data, showing an 84% concordance.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.