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This study aims to contribute to understanding the processes influencing the spatial distributions of trace metal elements in surface sediments of Brenne’s ponds (France) and assess potential pollution levels in the area. It was motivated by the lack of knowledge regarding the hydrogeochemical dynamics of limnic entities, which are ponds. To achieve this, 25 sediment samples were collected from Pond Thomas, considered as a ‘sentinel pond’, and underwent analysis for grain size, total organic carbon (TOC) concentrations, and trace metal elements (TMEs) (specifically Cu, Ni, Pb, As, Zn, Cr, and Cd). The results revealed that trace metal elements are primarily concentrated in two areas: the northwest section and the upstream region in the southern part of the pond. Applying various pollution indicators such as the enrichment factor (EF), geo-accumulation index (Igeo), and potential ecological risk index (RI), it was found that Pb and As are the most enriched elements, with respective EFs of 3.5 and 4.9. Their average concentrations exceed geochemical background values by 4 and 5.68 times in certain samples. The sediments in the southern part of the pond showed moderate contamination levels for As and Pb, with moderate to severe pollution (2 < Igeo < 3), reaching a maximum Igeo of 2.26 for As. Although the RI values across the pond are relatively low, Cd and As still pose moderate potential ecological risks. Additionally, principal component analysis and Pearson correlation analysis indicated two sources of TMEs in the area: Zn, As, Ni, Cd, Pb, and Cr are primarily from natural sources, while Cu appears to have a local anthropogenic origin. [ABSTRACT FROM AUTHOR]

In arid regions with increasing water needs due to growing populations and agriculture, heightened by climate change, groundwater arises as a crucial asset. This research evaluated climate change influence on groundwater potential zones (GPZs) during 2000 and 2014, within the Mostaganem plateau's alluvial aquifer in Algeria, using a methodology that integrates analytical hierarchy process (AHP), remote sensing (RS) and geographic information system (GIS). Forecasts for 2030 and 2050 were conducted using the QGIS MOLUSCE plugin. Findings reveal a (30.29%) decrease in zones of moderate potential, the vanishing of high potential sectors, alongside a (7.53%) and a (22.1%) rise in fair potential and low potential, respectively, from 2000 to 2014. Between 2014 and 2030, fair and moderate potential decrease by 6.62% and 0.48%, while low potential zones see a 7.47% increase. These shifts are linked to changes in rainfall distribution, and land use land cover (LULC), notably intensive agriculture of herbaceous crops. Slight changes are anticipated between 2030 and 2050, possibly due to the onset of a resilience equilibrium from 2030 onwards. These findings are crucial as a preliminary investigation, highlighting the necessity of optimal groundwater management. [ABSTRACT FROM AUTHOR]

The interactions between the normalised difference vegetation index (NDVI), the normalised difference built-up index (NDBI), and land surface temperature (LST) are complex. The assessment of land use/land cover (LULC) changes in the North-western region of Algeria between 1995 and 2021 confirms the direct influence of these factors on surface thermal processes. The use of new information technologies, particularly remote sensing coupled with GIS, favourably contributes to the processing of a large volume of data and to the use of specific methods aimed at confirming and/or disproving the hypotheses put forward. The application of LULC classification methods clearly highlights the magnitude of transformations, predominantly in favour of intensified urbanisation over the past two decades. Indeed, agricultural lands have experienced a reduction of 17.45%, while urbanised areas have nearly doubled. This phenomenon can, in part, be attributed to the mass migration of populations from inland areas to the coast, not only due to climate change: secondary for political problems between 1990 and 2001. Similarly, barren lands have increased by 10.45%. These changes have real implications for ecosystems (mainly loss of biodiversity) and the climate (pollution, GHG emissions, and rising ambient temperatures). The estimation of average LST from multiple satellite scenes reveals an increasing trend, rising from 36.6 °C in 1995 to 40.35 °C in 2021. The direct relationship between LST and NDVI and between LST and NDBI confirms the close association between land use change and increasing surface temperatures. The Pearson coefficient between LST and NDVI showed a negative correlation, ranging between -0.52 and -0.47, while it was positively correlated between LST and NDBI, with values around 0.66. The emergence of hotspots in the region, confirmed by the results of analysis employing the Getis-Ord G* method, is marked by clearly increasing spatial envelopes. This phenomenon is associated with a distinct reduction in vegetation cover density, coupled with an increased vulnerability to drought conditions. These initial results argue in favour of preserving green and blue networks and, more largely, ecosystems. [ABSTRACT FROM AUTHOR]

Given the absence of soil loss indicators within the Land Degradation Neutrality (LDN) framework, this study integrates land cover suitability, soil erosion and sediment transport as complementary Mediterranean-tailored indicators. The 309km² Lebanese Nahr Ibrahim basin was chosen for this purpose. Land cover suitability was determined by combining land capability-land cover maps, while soil erosion and sediment transport were assessed using the CORINE and SWAT models, respectively. Under current conditions, the following was found: a 34.84% land cover suitability; 4% low, 39.55% moderate and 56.45% high soil erosion risks zones, and 2.85% low, 26% moderate and 68.15% high sediment yields zones. Through the LDN response strategy based land use plan, land cover suitability increased by 26.54%, while soil erosion risks changed by: -3.1% low, -10.85% moderate and -18% high risk zones. For sediment transport, changes were: 0% low, -10.85% moderate and -18% high risk zones, hence the multi-effectiveness of LDN. [ABSTRACT FROM AUTHOR]

Land use planning for flood risk reduction has been significantly addressed in literature. However, a clear methodology for flood mitigation oriented land-use planning and its implementation, particularly in developing countries like Lebanon, is still missing. Knowledge on land use planning is still in its earliest stages in Lebanon. A lack of hazard-informed land use planning coupled to random land cover pattern evolution characterize the country. In response, this study focuses on the opportunities, challenges and uncertainties resulting from the integration of land use planning into efficient Disaster Risk Reduction (DRR). For this purpose, GIS-based analyses were first conducted on the current land use/land cover (LU/LC) of the Assi floodplain. Then, the areas land cover was retraced and its evolution after several flood occurrences was assessed. Subsequently, a flood hazard-informed LU/LC plan was proposed. The latter is mainly based on the spatial allocation of land-uses with respect to different flood hazard levels. This approach resulted in the production of a land use planning matrix for flood risk reduction. The matrix approach can serve as a tool for designing sustainable and resilient land cover patterns in other similar contexts while simultaneously providing robust contributions to decision-making and risk communication. [ABSTRACT FROM AUTHOR]

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The impact of ponds on basins has recently started to receive its well-deserved scientific attention. In this study, pond-induced impacts on soil erosion and sediment transport were investigated at the scale of the French Claise basin. In order to determine erosion and sediment transport patterns of the Claise, the Coordination of Information on the Environment (CORINE) erosion and Soil and Water Assessment Tool (SWAT) models were used. The impact of ponds on the studied processes was revealed by means of land cover change scenarios, using ponded versus pondless inputs. Results show that under current conditions (pond presence), 12.48% of the basin corresponds to no-erosion risk zones (attributed to the dense pond network), while 65.66% corresponds to low-erosion risk, 21.68% to moderate-erosion risk, and only 0.18% to high-erosion risk zones. The SWAT model revealed that ponded sub-basins correspond to low sediment yields areas, in contrast to the pondless sub-basins, which yield appreciably higher erosion rates. Under the alternative pondless scenario, erosion risks shifted to 1.12%, 0.52%, 76.8%, and 21.56% for no, low, moderate, and high-erosion risks, respectively, while the sediment transport pattern completely shifted to higher sediment yield zones. This approach solidifies ponds as powerful human-induced modifications to hydro/sedimentary processes. [ABSTRACT FROM AUTHOR]

Abstract Recognized by the United Nations Convention to Combat Desertification (UNCCD) as a global developmental and environmentally threatening process, land degradation (LD) is initiated by natural factors but aggravated by unsustainable anthropogenic activities and absence of proper management plans. Therefore, in response to the UN 2030 Agenda on Sustainable Development for restoring degraded lands, this research targets the impact of land use and land cover changes (LU/LC), under the UNCCD's Land Degradation Neutrality (LDN) concept, to identify the extent of LD, and to prospect the potential to counterbalance/neutralize ongoing degradation as a first approach to Lebanon, at the scale of the 301 Km2 Awali basin. By achieving this task, the proposed method will serve as a first step in building an inventory of LD and proposing measures to adapt or even overcome LD for applications in the Mediterranean basin's countries. The proposed sequential methodological approach consists of tracking detailed LU/LC changes from 1998 to 2016 using multitemporal satellite images. Generated maps are input to the Soil Conservation Service SCS-Curve Number (CN) method to determine surface runoff in complementarity to Pedological properties of the study area. Soil types are then classified under the USDA Land Capability Classification method to determine extent of degraded lands. Results intersected with LU/LC revealed the source and nature of mismanagement and the proposed counterbalancing steps. Two main findings result: the Awali watershed displays countable LU/LC changes translated in CN increases. Additionally, due to these changes, the basin displays a 36% LD that may continue to alarming rates if no intervention takes place. The proposed workflow combining existing methodologies enabled the application of the LDN concept to counterbalance losses by gains thus reducing degradation to 2% from alternative land planning, and near null from proposed soil corrective actions highlighting the importance of LDN usage. Highlights • Through a time series approach, countable land use changes have been tracked. • Unsustainable land use and lack of land planning resulted in 39% land degradation. • Land Degradation Neutrality concept introduced to a Mediterranean watershed • This concept coupled to land capability classification highlighted degraded zones. • The proposed methodological approach resulted in 87% decrease of land degradation. [ABSTRACT FROM AUTHOR]