scholarly journals Assessment of Groundwater Vulnerability in the North Aquifer Area of Rhodes Island Using the GALDIT Method and GIS

Environments ◽  
2019 ◽  
Vol 6 (5) ◽  
pp. 56
Author(s):  
Zografina Mavriou ◽  
Nerantzis Kazakis ◽  
Fotios-Konstantinos Pliakas

Salinization of coastal aquifer systems constitutes a major threat for groundwater. Especially areas with high population density due to increasing tourist activity may face severe problems. In this study, the GALDIT method was applied in the north side of Rhodes Island, Greece, in order to assess groundwater vulnerability to seawater intrusion. Hydrogeological data were elaborated in geographical information systems (GIS), and appropriate thematic maps were produced. The final vulnerability map was obtained from the combination of the thematic maps using overlying techniques. Based on the application of the GALDIT method, a zone up to 1000 m from the shore is characterized by medium to high vulnerability, while medium vulnerability characterizes the eastern part of the study area. Overexploitation of the aquifer, due to the intense touristic activity in Ialysos area, constitutes the main reason for groundwater salinization due to seawater intrusion in the study area. Consequently, planning of proper groundwater management and systematic monitoring of the groundwater reserves are of the utmost importance in order to solve existing problems and prevent future issues of salinization.

2017 ◽  
Vol 25 (1) ◽  
pp. 37-63
Author(s):  
mohammad abbas daoudi mohammad abbas daoudi

The problems of soil erosion are largely widespread in the countries of the Mediterranean basin. The process of gullying is a complex phenomenon with disastrous consequences. It particularly affects northern Algeria, decreasing the potentialities of the water tanks, reducing cultivable lands availability and degrading infrastructures. Therefore, this work studies the analysis and the prediction of gullying erosion by using a probabilistic approach based on multisource data. The objective of this search is to answer to the three following questions: i) which factors support the process of gullying ? ii) how does a process of gullying develop? iii) which are the zones favourable to gullying ? Works are undertaken on the catchment area of the Isser River. We focused the applications on the upstream part of the basin. In this research, we study a North-South transect which corresponds to three under-basins slopes. The choice of these tests areas answers to four criteria defined in our method: the representativeness, the homogeneity, the availability of former data and, finally, the accessibility. After the completion of the multisource data, modelling and multivariate analysis for the prediction of gullying. The combination factor-process by the univariate analysis allows on the one hand, to highlight the variables controlling the process of gullying, and on the other hand, to analyse the variables on a hierarchical basis and to know their degree of influence. The multivariate analysis, by the logistic regression model (LRM), enabled us to select the significant variables and to locate the most favourable zones for the process of gullying. The validation of the models is evaluated using the curves of lift spin. The results suggest that the factors highlighted by the model to be most influential on gullying erosion are: the lithology, the slope, the morphopedology, the rainfall erosivity and the land cover. The synthesis of this approach is illustrated in the form of charts of gullying erosion risk maps in four classes of probability. The assessment of the study shows the fundamental interest of this approach using geographical information systems and remote sensing, in particular for the watersheds of the southern Mediterranean, with the possibility of extending this methodology to other regions.


2018 ◽  
Vol 54 ◽  
pp. 00023 ◽  
Author(s):  
Dawid Potrykus ◽  
Anna Gumuła-Kawęcka ◽  
Beata Jaworska-Szulc ◽  
Małgorzata Pruszkowska-Caceres ◽  
Adam Szymkiewicz ◽  
...  

In this research, GALDIT method was used to assess seawater intrusion in the coastal aquifer of the inner Puck Bay (Southern Baltic Sea). The impact of potential sea-level rise on groundwater vulnerability for years 2081-2100 was also considered. The study area was categorized into three classes of vulnerability: low, moderate and high. The most vulnerable area is the Hel Peninsula with northern part of the Kashubian Coastland. Increased class of aquifer vulnerability is also adopted to glacial valleys. The results of this research revealed that about 18.9% of the analyzed area is highly vulnerable to seawater intrusion, 25.3% is moderately vulnerable and 55.8% is potentially at low risk. The simulated scenario of predicted sea level rise shows enlargement of high vulnerability areas.


2017 ◽  
Vol 50 (2) ◽  
pp. 798 ◽  
Author(s):  
I. Lappas ◽  
A. Kallioras ◽  
F. Pliakas ◽  
Th. Rondogianni

Groundwater resources assessment has resulted in development of models that help identify the vulnerable zones. This paper presents a GIS-based hydrogeological index, named GALDIT, aiming at the assessment of aquifer vulnerability to seawater intrusion in Atalanti coastal aquifer, Central-Eastern Greece. The above acronym is formed from the most important factors controlling seawater intrusion, that is, four intrinsic hydrogeological parameters, one spatial parameter and one boundary parameter including Groundwater occurrence (aquifer type), Aquifer hydraulic conductivity, depth to groundwater Level above the sea (hydraulic head), Distance from the shore, Impact of seawater intrusion and aquifer’s Thickness. These factors nclude the basic requirements needed to assess the general salinization potential of each hydrogeological setting. Each parameter is evaluated with respect to the other to determine the relative importance of each factor. GALDIT model is described to assess and quantify the significance of vulnerability to seawater intrusion due to excessive groundwater withdrawals. Different thematic maps are prepared for seawater intrusion indicators and overlaid to develop the final vulnerability map. The derived map can be used as a tool for coastal groundwater resources management and areas’ determination of potential saltwater intrusion since the result of GALDIT ndex is classified based on vulnerability rate.


2019 ◽  
Vol 13 (2) ◽  
pp. 157-166
Author(s):  
Loredana Copăcean ◽  
Ionut Zisu ◽  
Valentina Mazăre ◽  
Luminiţa Cojocariu

The soil, regarded as a natural resource, but also as a determinant element of the living standards of rural communities, manly agricultural, may be influenced, directly and indirectly, by the modality of land organizing and use. Starting from this consideration, through this study, the spatial and temporal evolution of land use is being pursued, particularly that of forest areas and wooded grasslands. The goal is to notice the changes that have occurred over a 30-year period and the manner how these changes are reflected on the soil features. The researches presented in this paper have been taking place in the north-eastern hilly area of Timiş County, that area having entirely a rural character. For realizing this study satellite images, topographical and cadastral maps, from different time periods, national and international databases, data from specialty literature were used. To all these we should add direct observations in the field, topographic surveys and information collected from local authorities. The processing of cartographic materials and data and scientific information has been realized with Geographical Information Systems specific applications. The obtained result has been expressed in the form of thematic maps, in graphic form or as statistical analysis. At the level of the analyzed area, the obvious changes in the land use, registered over time, are caused by a number of factors, such as: the organization form, from communist to capitalist policies, leaving agricultural land as fallow ground, reduction in livestock, changing land use etc. All these changes have caused the extension of the wooded grasslands, reduction of arable land, installing inferior forest vegetation in qualitative and quantitative terms etc. As a result, the soil, one of the most important natural resources, is degraded qualitatively, underexploited, and on the other hand, its role as a direct and indirect food producer for local communities is significantly reduced.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Ebrahim Babaee ◽  
Gholamreza Roshandel ◽  
Meysam Olfatifar ◽  
Arash Tehrani-Banihashemi ◽  
Arezou Ashaari ◽  
...  

Cancer is a problem of both global and local concern. We determined the geo-epidemiological and spatial distribution of the 10 most common cancers in Iran. We used the data of the Iranian Cancer Registry for the year 2014 analysing the prevalence of 112,131 registered cancer cases with the aim of detecting potential geographical underlying causes. The geographic distribution of cancers is reported as standardized incidence rates at the provincial level considering risk with respect to sex and age. A geographical information systems (GIS) approach based on Anselin Local Moran’s index method was used to map clusters and spatial autocorrelation patterns. The mean age of the patients was 55.6 (±17.8) and 61.7 (±18.2) for females and males, respectively, in the database which showed 46.1% (n=51,665) of all cases to be female. Analysis of the spatial distribution of cancers showed significant differences among the different provinces. Stomach and breast cancers were the most prevalent cancers in men and females, respectively. The highest incidence rates of stomach cancer were found in Ardabil and Zanjan provinces, with 48.38 and 48.08 per 100,000 population, respectively, while Tehran and Yazd provinces had the highest incidences of breast cancer, 51.0 and 47.5 per 100,000 population, respectively. Strong clustering patterns for stomach and breast cancers were identified in the north-western provinces and in Semnan Province, respectively. These patterns indicate a diversity of geo-epidemiological contributing factors to cancer incidence in Iran.


2021 ◽  
pp. jgs2020-158
Author(s):  
Jack Lovegrove ◽  
Andrew J. Newell ◽  
David I. Whiteside ◽  
Michael J. Benton

The Rhaetian transgression marked a major change in landscape. The Permian and Triassic had been a time of terrestrial conditions across Europe, including much of mainland UK, as well as the North Sea and Irish Sea, represented by red bed clastic successions. Seas flooded across Europe at 205.7 Ma and the shift from terrestrial to marine environments is marked in the UK by the switch from the red beds of the Mercia Mudstone Group to the black mudstones and shelly limestones and sandstones of the Penarth Group. The area around Bristol was marked by a complex landscape in which an archipelago of islands of Carboniferous limestone was formed in the new shallow seas. The application of new methods in geographical information systems allows a detailed exploration of a number of conformable surfaces, the unconformity between the underlying Paleozoic rocks and the overlying Mesozoic strata, as well as levels within the latest Triassic sediments, marking the advance of the sea and interactions with the coeval tectonics, which caused some islands to rise and some basins to descend. The new geographical information system models show a sequence of palaeogeographical reconstructions of the archipelago and relate this to the island tetrapod faunas, which show strong evidence of the species–area effect.Supplementary material: Supplementary tables S1-S6 and 2D island map GIS files are available at https://doi.org/10.6084/m9.figshare.c.5273256


2017 ◽  
Vol 50 (2) ◽  
pp. 750
Author(s):  
E. Kiri

Prespa Lake Basin is a transboundary basin that’s shared between Albania-Greece-FYROM. This region has a very complicated geology. The main aquifer systems are developed in carbonate rocks (karst aquifers) crossing international borders (transboundary aquifers). A map was constructed in GIS environment clearly display that each geologic age has one index, in one polygon, with the respective geological formation. The map was first digitalized with an AutoCAD program and then all the layers were exported in the program mentioned above. Not only does this map represent the hydrogeological features of the area but it also serves as a database of general characteristics, such as, the rock type, the infiltration coefficient, the yield of wells and springs, groundwater resource and permeability can be found on this base. Furthermore, chemical data can be added to the map, supplying more information on the surface and groundwater. Geographical Information Systems (GIS) is a useful tool for water resources management in the frame of international cooperation and coordination.


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