History and formation of African Lakes

Ali, M. M.; Ellah, Radwan G. Abd

doi:10.1016/b978-0-323-95527-0.00015-4

Cited by 3 publications

(1 citation statement)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The physiographic data on Tunisia present moderate hilly terrain with the slope geomorphology ranging from zero m in the coastal areas at water level to the maximum at 3781 m and mean at 432 m, according to the General Bathymetric Chart of the Oceans (GEBCO) DEM grid. The geographical location of these sebkhas is related to the environmental historical development of north Sahara with related aeolian and fluvial pro-cesses [69,70]. Located in the arid environment of north Africa, saline lakes and surrounding landscapes experience changes in volume and extent due to the extreme temperatures: during the summer heat period, lakes dry out almost entirely and become a crust of salt and minerals due to the evaporated moisture.…”

Section: Study Areamentioning

confidence: 99%

Monitoring Seasonal Fluctuations in Saline Lakes of Tunisia Using Earth Observation Data Processed by GRASS GIS

Lemenkova

2023

Land

View full text Add to dashboard Cite

This study documents the changes in the Land Use/Land Cover (LULC) in the region of saline lakes in north Tunisia, Sahara Desert. Remote sensing data are a valuable data source in monitoring LULC in lacustrine landscapes, because variations in the extent of lakes are visible from space and can be detected on the images. In this study, changes in LULC of the salt pans of Tunisia were evaluated using a series of 12 Landsat 8-9 Operational Land Imager (OLI) and Thermal Infrared (TIRS) images. The images were processed with the Geographic Resources Analysis Support System (GRASS) Geographic Information System (GIS) software. The study area included four salt lakes of north Tunisia in the two regions of the Gulf of Hammamet and Gulf of Gabès: (1) Sebkhet de Sidi el Hani (Sousse Governorate), (2) Sebkha de Moknine (Mahdia Governorate), (3) Sebkhet El Rharra and (4) Sebkhet en Noual (Sfax). A quantitative estimate of the areal extent analysed in this study is 182 km × 185 km for each Landsat scene in two study areas: Gulf of Hammamet and Gulf of Gabès. The images were analysed for the period 2017–2023 on months February, April and July for each year. Spatio-temporal changes in LULC and their climate–environmental driving forces were analysed. The results were interpreted and the highest changes were detected by accuracy assessment, computing the class separability matrices, evaluating the means and standard deviation for each band and plotting the reject probability maps. Multi-temporal changes in LULC classes are reported for each image. The results demonstrated that changes in salt lakes were determined for winter/spring/summer months as detected changes in water/land/salt/sand/vegetation areas. The accuracy of the classified images was evaluated using pixel rejection probability values, which were filtered out using the ‘r.mapcalc’ module of GRASS GIS. The confidence levels were computed and visualised with a series of maps along with the error matrix and measured convergence level of classified pixels. This paper contributes to the environmental monitoring of Tunisian landscapes and analysis of climate effects on LULC in landscapes of north Africa.

show abstract

Section: Study Areamentioning

confidence: 99%

Monitoring Seasonal Fluctuations in Saline Lakes of Tunisia Using Earth Observation Data Processed by GRASS GIS

Lemenkova

2023

Land

View full text Add to dashboard Cite

show abstract

Current evaluation of radiation hazards from sediments of Manzala Lake, Egypt

Abd El-Hamid,

El-Emam,

Eissa

et al. 2024

J Radioanal Nucl Chem

View full text Add to dashboard Cite

Surface sediment samples were collected from 12 different sites in Manzala Lake for measuring 238U, 226Ra, 232Th and 40K. Those elements were measured using High Purity Germanium (HPGe) detector. The concentrations of radionuclides were within the UNSCEAR limits. Various indices were applied to detect the environmental and human risk assessment for example activity utilization index, external hazard index and others. Environmental Risk from Ionising Contaminants: Assessment and Management (ERICA) tool was applied and showed no considered biological hazards. The results showed that concentrations of radionuclides in sediments of Manzala Lake were within the safe limits for further uses.

show abstract