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Aim :To analyse the patterns in species richness and endemism of the native European riverine fish fauna, in the light of the Messinian salinity crisis and the Last Glacial Maximum (LGM). Location :European continent. Methods :After gathering native fish faunistic lists of 406 hydrographical networks, we defined large biogeographical regions with homogenous fish fauna, based on a hierarchical cluster analysis. Then we analysed and compared the patterns in species richness and endemism among these regions, as well as species-area relationships. Results :Among the 233 native species present in the data set, the Cyprinidae family was strongly dominant (> 50% of the total number of species). Seven biogeographical regions were defined: Western Peri-Mediterranea, Central Peri-Mediterranea, Eastern Peri-Mediterranea, Ponto-Caspian Europe, Northern Europe, Central Europe and Western Europe. The highest regional species richness was observed for Central Peri-Mediterranea and Ponto-Caspian Europe. The highest endemic richness was found in Central Peri-Mediterranea. Species-area relationships were characterized by high slope values for Peri-Mediterranean Europe and low values for Central and Western Europe.Main conclusions :The results were in agreement with the \"Lago Mare\" hypothesis explaining the specificity of Peri-Mediterranean fish fauna, as well as with the history of recolonization of Central and Western Europe from Ponto-Caspian Europe following the LGM. The results also agreed with the mechanisms of speciation and extinction influencing fish diversity in hydrographical networks. We advise the use of the seven biogeographical regions for further studies, and suggest considering Peri-Mediterranean Europe and Ponto-Caspian Europe as \"biodiversity hotspots\" for European riverine fish.

Studying fluvial dynamics and environments, GIS-based analyses are of fundamental importance to evaluate the network geometry and possible anomalies, and can be particularly useful to estimate modifications in processes and erosion rates. The aim of this paper is to estimate short-term erosion rates attributable to fluvial processes in two sample catchment sub-basins of the Marecchia river valley, by conducting quantitative morphometric analyses in order to calculate various descriptive parameters of the hierarchisation of the river networks and the mean turbid transport of streams (Tu). Sediment yield transported by streams can in fact partially express the amount of erosional processes acting within the drainage basin. The study area includes two sub-basins of the Marecchia valley (Senatello river, 49 km2 and Mazzocco river, 47 km2), chosen because of their similar extent and of the different location in the major catchment basin. Starting from geomorphological maps of the two river basins, the Tu parameter has been calculated and converted in short-term rate (average value 0.21 mm/year). Moreover, the comparison of these short-term mean data with the uplift rates calculated on a regional scale (0.41 ± 0.26 mm/year) in the Marecchia valley confirms that the northern Apennines may represent a non-steady state system.

Understanding a catchment’s geomorphological and erosion processes is essential for sustainable land management and soil conservation. This study investigates the Xynias drained lake catchment in Central Greece using a twofold geospatial modelling approach that combines morphometric analysis with the Revised Universal Soil Loss Equation (RUSLE) to evaluate the area’s landscape evolution, surface drainage features, and soil erosion processes. The catchment exhibits a sixth-order drainage network with a dendritic and imperfect pattern, shaped by historical lacustrine conditions and the carbonate formations. The basin has an elongated shape with steep slopes, high total relief, and a mean hypsometric integral value of 26.3%, indicating the area is at an advanced stage of geomorphic maturity. The drainage density and frequency are medium to high, reflecting the influence of the catchment’s relatively flat terrain and carbonate formations. RUSLE simulations also revealed mean annual soil loss to be 1.16 t ha−1 y−1 from 2002 to 2022, along with increased erosion susceptibility in hilly and mountainous areas dominated by natural vegetation. In comparison to these areas, agricultural regions displayed less erosion risk. These findings demonstrate the effectiveness of combining GIS with remote sensing for detecting erosion-prone areas, informing conservation initiatives. Along with the previously stated results, more substantial conservation efforts and active land management are required to meet the Sustainable Development Goals (SDGs) while considering the monitored land use changes and climate parameters for future catchment management.

The present study focuses on the extraordinary isolated high-level depression event that occurred on 29 October 2024 over the eastern Iberian Peninsula (Spain). The emphasis of the study is on the Turia and Magro river basins and the Albufera of Valencia lagoon basin, with particular attention given to the hydrological implications of the event in these areas. It is an established fact that episodes of intense precipitation give rise to flash floods. This recurrent phenomenon has significant economic and human impacts, and is particularly prominent in the Mediterranean region, including the Valencian Community (Eastern Spain). The estimation of peak flows at key sites in the basins was achieved through the utilization of an empirical methodological approach based on fieldwork to obtain the wetted cross-section of each site of analysis. Utilizing the existent official flow-measuring data network, an estimation was made of the average velocity of the water. The results indicate that flows in several locations exceeded the carrying capacity of the watercourses, leading to substantial flooding and overflows. The maximum estimated peak flow was determined to be 5678 m3 s−1 in the Poyo ephemeral stream and 4198 m3 s−1 in the Magro river. The results were validated using the Manning equation and related stream parameters (such as roughness and slope), obtaining a normalized root mean squared error of 3.62% and normalized mean absolute error of 2.26%. This analysis identified bottlenecks in the hydrographic network and emphasized the necessity to enhance detailed knowledge of the hydraulic capacity of watercourses. This helps with the purpose of flood risk management in the event of extreme future events accentuated by climate change.

We present the result of the geomorphological mapping of the central sector of the Kurdistan Region of Iraq. Therein, landscape evolution was mostly overseen by the regional geodynamic, related to the Arabia-Eurasia convergence, and in the Quaternary, regional climate fluctuations contributed to shaping landforms. The combination of such processes affected the distribution, types, and evolution of landforms (related to structural, hillslope, fluvial, and karst processes), with a noteworthy influence on the development of the local drainage network, which belongs to Tigris River catchment. The Great Zab and Little Zab Rivers - the main left tributaries of Tigris River - progressively cut anticline ridges growing in the area. Our analyses suggest that the structural deformation of the Zagros also controlled the evolution of the low-order channels of the hydrographic network. Since the Holocene, landforms dynamic was altered by intense human exploitation of the landscape and increased fluctuations between arid and humid conditions.

The article presents the outcomes of an assessment of hydrographic network changes within the Almaty city, utilizing geographic information system (GIS) technology and Earth remote sensing data. Two gauge stations were selected along the main rivers within the Almaty city. To identify distinctive alterations in these rivers, hydrological data series encompassing the maximum runoff from 1970 to 2021 were collected and subjected to statistical analysis. Differential integral curves were constructed to pinpoint periods corresponding to peak and trough runoff levels. For each of these identified periods, the processing of satellite imagery allowed for the computation of meandering coefficients for the river channels. Additionally, refinements were made to the slope values of the rivers during these same timeframes, and connectivity graphs were established to elucidate the relationship between slope and liquid runoff for each period. The analysis encompassed an assessment of the impact of anthropogenic factors on both artificial and natural bodies of water while also considering shifts in the boundaries of the Almaty city. The findings derived from this study have practical applications in the planning and design of water supply systems and in the implementation of measures aimed at mitigating the adverse effects of anthropogenic factors on water bodies.

In the Mediterranean Sea, two critical issues affect marine benthic biocenosis: sedimentation and the increasing trend in marine biodiversity loss. These processes are very marked along the western side of the Calabrian coastline, where siltation is one of the main reasons for the regression of Posidonia beds in the regional coastal waters. This study investigates the relationships between the geomorphological features of the debris source areas, represented by fluvial basins, and the distribution of Posidonia meadows. So, a concise geomorphological study of the Tyrrhenian fluvial basins with an area greater than 200 km2 was carried out, and we correlated the results with the mapping of the meadows in Calabria’s Tyrrhenian waters. Furthermore, to assess the increased level of burial in a Posidonia oceanica meadow and its health state over time, a program of Posidonia monitoring was undertaken between 2000 and 2010 in a test area located in the Marine Regional Park of Isca (Calabria, Southern Italy). The results of this survey highlighted that, at the beginning of the study period, the silting rate of 4–5 cm/year saw the meadow suffer a reduction in its photosynthetic ratio with a mortality rate of 50%. The siltation rate reached 12 cm/year in 2010, and the meadow began to disappear. Therefore, marine pollution via sedimentation represents a serious factor in the regression of Posidonia oceanica meadows and enhances the risk of a gradual loss of marine biodiversity.

Continental ice sheets are a key component of the Earth’s climate system, but their internal dynamics need to be further studied. Since the last deglaciation, the northern Eurasian Fennoscandian Ice Sheet (FIS) has been connected to the Black Sea (BS) watershed, making this basin a suitable location to investigate former ice-sheet dynamics. Here, from a core retrieved in the BS, we combine the use of neodymium isotopes, high-resolution elemental analysis, and biomarkers to trace changes in sediment provenance and river runoff. We reveal cyclic releases of meltwater originating from Lake Disna, a proglacial lake linked to the FIS during Heinrich Stadial 1. Regional interactions within the climate–lake–FIS system, linked to changes in the availability of subglacial water, led to abrupt drainage cycles of the FIS into the BS watershed. This phenomenon raised the BS water level by ∼100 m until the sill of the Bosphorus Strait was reached, flooding the vast northwestern BS shelf and deeply affecting the hydrology and circulation of the BS and, probably, of the Marmara and Aegean Seas.

This article presents the Base Point Split (BPSplit) algorithm to generate a complex polygon skeleton based on sets of vector data describing lakes and rivers. A key feature of the BPSplit algorithm is that it is dependent on base points representing the source or mouth of a river or a stream. The input values of base points determine the shape of the resulting skeleton of complex polygons. Various skeletons can be generated with the use of different base points. Base points are applied to divide complex polygon boundaries into segments. Segmentation supports the selection of triangulated irregular network (TIN) edges inside complex polygons. The midpoints of the selected TIN edges constitute a basis for generating a skeleton. The algorithm handles complex polygons with numerous holes, and it accounts for all holes. This article proposes a method for modifying a complex skeleton with numerous holes. In the discussed approach, skeleton edges that do not meet the preset criteria (e.g., that the skeleton is to be located between holes in the center of the polygon) are automatically removed. An algorithm for smoothing zigzag lines was proposed.

The impact of extracting lignite in Lupoaia open pit over waters is local and regional, and temporary. The hydrographic network in Lupoaia open pit depends on River Motru, with its afluents, Ploștina and Lupoița Valley Rivers. The aquifers are to be found in the coal layers V-XII, mainly of sands formation. The impact over water in Lupoaia consists of water pollution and of changes in both the quality and the quantity of ground and surface waters. The surface waters are polluted resulting in industrial wastewaters, household wastewaters and waste rainwater. The wastewater is polluted within maximum admitted limits. The quality of groundwaters is influenced and modified by extracting coal resulting in the extinction of some aquifers. Environmental risks that can occur when extracting lignite are water floods, landslides, disasters which can be prevented by building guard channels around the open pit. The actions for reducing the impact are, in general, accomplished through monitoring both the water pollutants and the morphological changes caused by extracting lignite. That is why wastewater treatment plants must function. The impact of the activity in Lupoaia open pit over the hydrographic net of the area is to be observed during the entire extracting period, and monitoring this activity is highly demanded by the European environmental protection laws.