Floodplain Research Articles

The Pannonian Stage: Stratigraphy and geo-energy resources

The youngest regional chronostratigraphic unit of the Central Paratethys, the Pannonian Stage, is benchmarked by the deposits of Lake Pannon, containing a highly endemic, Caspian-type biota, and the sediments of adjacent deltas and fluvial plains. The Pannonian Stage also includes various freshwater lake deposits and vast volcanic formations, especially in the northern and eastern margins of the Pannonian Basin system. The Pannonian correlates with the Tortonian, Messinian, Zanclean and Piacenzian Stages, thus represents 9 Myr between 11.6 and 2.6 Ma. The Pannonian is divided into biochronostratigraphic units by the application of mollusc and dinoflagellate biochronozones in the Lake Pannon deposits and mammal biozones in the freshwater sediments. The Pannonian Stage is a leading geo-energy provider in terms of hydrocarbons and lignite. Prolific oil and gas reservoirs occur in both the deep-water and deltaic sand bodies in the central part of the Pannonian Basin, which is a highly mature exploration area. The practically inexhaustible lignite resource of the Pannonian Stage has been mined or is still being mined in the basin margins in all ten countries of the Pannonian Basin system.

A preliminary macroinvertebrate index of biotic integrity (M-IBI) for monitoring the highland flood plain wetland ecosystems in Ethiopia

Anthropogenic activities have put tremendous pressure on the natural condition of wetlands. However, few studies have used indices based on benthic invertebrates to assess the effect of these pressures on wetland ecosystems. Multi-metric indices (MMIs) have been used successfully to assess freshwater ecosystems worldwide and are an important management tool, but little is known about their applicability in the wetlands of Ethiopia. In this study, we developed MMIs for wetland invertebrates to assess wetlands in Ethiopia. The wetland invertebrate assemblages were sampled from 24 sampling stations in six wetlands in the Achefer flood plains. These sampling stations included those in least affected areas and those affected by adjacent, agricultural and urban activities. Forty-one candidate metrics were initially reviewed and screened before six core metrics were selected: Taxa richness, ET taxa richness, % EOT, % Diptera, % Collector/Filterer and % intolerant taxa. Mann–Whitney U tests, Box and Whisker plots, correlation analyses, and redundant metric tests were used to assess the ability of metrics to distinguish among reference and impaired wetlands. The MMIs were robust in discriminating reference wetlands from impaired wetlands and therefore have potential as a biomonitoring tool to assess the condition of, and to guide efforts to restore, freshwater wetlands.

Simulating the effects of sea level rise and soil salinization on adaptation and migration decisions in Mozambique

Abstract. Coastal flooding and sea level rise (SLR) will affect farmers in coastal areas, as increasing salinity levels will reduce crop yields, leading to a loss of net annual income for farming communities. In response, farmers can take various actions. To assess such responses under SLR, we applied an agent-based model (ABM) to simulate the adaptation and migration decisions of farmers in coastal Mozambique. The ABM is coupled with a salinization module to simulate the relationship between soil salinity and SLR. The decision rules in the model (DYNAMO-M) are based on the economic theory of subjective expected utility. This theory posits that households can maximize their welfare by deciding whether to (a) stay and face losses from salinization and flooding, (b) stay and adapt (e.g. switching to salt-tolerant crops and enhancing physical resilience such as elevating houses), or (c) migrate to safer inland areas. The results show that coastal farmers in Mozambique face total losses of up to USD 12.5 million yr−1 from salt intrusion and up to USD 1200 million yr−1 from flooding of buildings (RCP8.5 in the year 2080). Sorghum farmers may experience little damage from salt intrusion, while rice farmers may experience losses of up to USD 4000 yr−1. We show that medium-sized farmers (1–5 ha) are most at risk. This is because their farm size means that adaptation costs are substantial, while their incomes are too low to cover these costs. The number of households adapting varies between different districts (15 %–21 %), with salt adaptation being the most common, as costs are lowest. Despite adaptation measures, about 13 %–20 % of the total 350 000 farmers in coastal flood zones will migrate to safer areas under different settings of adaptive behaviour and different climatic and socio-economic scenarios.

The modern state of the soil cover of the Transcarpathian lowland: diversity, properties and development dynamics of natural and anthropogenic soils

The regularities and peculiarities of the modern state of the soils of the floodplain complexes of the Transcarpathian lowland under the influence of natural and anthropogenic factors were investigated. Prognostic modeling of the dynamics of the further development of soils and soil cover in the region was carried out. It was established that a significant mosaic in space and dynamism characterize the soil cover of floodplains in time. Alluvial, semi-hydromorphic, and hydromorphic soils dominate the flood plains of Transcarpathian rivers. Alluvial soils were the dominant types in the pre-anthropogenic period. They develop in conditions of constant soil ground water level and periodic surface flooding by floodwaters. Alluvial sediment (silt) remains on the surface after the subsidence of flood waters and has a significant impact on the properties, morphology, lithology and fertility of soils. The high content of dusty ground particles in all variants of river silt ensures their rapid inclusion in the process of soil formation and contributes to the improvement of water-physical and physic-chemical properties of alluvial soils. First of all, alluvial soils significantly suffer from anthropogenic interference in the course of flood processes undergo critical changes in water-physical and physic-chemical properties. After the improve of melioration measures that regulate the flood regime in floodplains, significant areas of soil lose alluvial features and later develop as semi-hydromorphic or hygromorphic. Drainage melioration, depending on the further direction of soil-forming processes, can have completely different effects on soil properties. Therefore, it is necessary to approach melioration measures very carefully, foreseeing in advance all the consequences, which may occur on drained territories. The possible profit from the involvement to agricultural production of drained areas can be incomparably smaller, compared to the losses for maintaining the normal functioning of not only these areas, but also the territories adjacent to them. The secondary anthropogenic load is often imposed on the primary hydrotechnical and reclamation soil transformation due to the active agricultural use of drained floodplains. Depending on the duration and method of agricultural production, soils that were formed as alluvial acquire new properties, different from natural ones. Their soil density and soil hardness increase, the water-air regime is disrupted, and their physical and chemical properties change. Deeply drained and additionally changed by technical means, the soils of the hydromorphic range, after the abandonment of resource-consuming extensive production, are left for natural self-recovery, and the further course of soil restoration processes requires careful study and control by scientists. A mosaic natural-anthropogenic soil cover of the alluvial lowland was formed under the combined effect of natural and anthropogenic processes, so alluvial soils need the greatest protection and protection in fact. Such soils are part of unique floodplain complexes, the study, preservation and protection of which should be the primary focus of both scientists and environmentalists.

Enhancing large-diameter timber production: Evaluating poplars by genotype and spacing

To meet the increased demand for construction timber, selecting large-diameter hybrid poplar genotypes and optimizing spacing are essential for enhancing stand productivity in Northeast China. In the Daling River Plain, a trial with 12 clones (G1∼G12) of Populus × euramericana at four spacings (2 m×5 m, 3 m×8 m, 4 m×8 m, 4 m×10 m) was conducted. Over a 14-year rotation, tree height, diameter at breast height, survival rate, individual tree volume, growing stock, and timber yield were measured and analyzed. Results showed that while tree height was minimally affected, diameter at breast height, survival rate, and growing stock were significantly influenced by genotype and spacing. Higher spacings inhibited growth but increased variability within the stand. Diameter at breast height in the 2 m×5 m spacing reached the large-diameter standard (24 cm) and provided a higher growing stock. The minimum density required for larger-diameter wood (diameter at breast height over 35 cm) was the 4 m×8 m spacing. GGE-Biplots identified the top five genotypes as G2, G4, G11, G1, and G10. Genotypes G4, G10, and G1 were suitable for low-density plantations, with G4 performing best, achieving a 95 % improvement in survival rate and a 105 % increase in growing stock. Genotypes G2 and G11 were ideal for high-density plantations, with G2 showing the best results, increasing survival rate by 36 % and growing stock by 56 %. The optimal period for early selection in P. × euramericana is the 4th to 5th year after afforestation. The best design, D1×G2, yielded 513 m³·ha⁻¹ of timber and 288.52 m³·ha⁻¹ of large-diameter wood. These findings support the establishment of large-diameter poplar plantations, aiding future breeding efforts and increasing stand productivity.

Flood Reduction and Prevention Possibilities in the Flood Plains: A Study of the Varuna River Basin in the Flood Plain of the Ganga River, Uttar Pradesh, India

ABSTRACT Floods are a recurring phenomenon in the floodplain region of the Ganga River largely caused by several floodplain tributaries. One such tributary of the Ganga in its floodplain is the 225 km long monsoon-fed Varuna River. Using high-resolution Google earth satellite images, 662tals (local word for large natural ponds), and 15383 other smaller ponds/ tanks (natural and man-made), were identified and delineated. The tals and ponds/tanks occupy 430 km2 and 93 km2 respectively, within the 3141 km2area of the Varuna River basin. Based on the areas and approximate water depths that were averaged from field measurements at selected tals and ponds/tanks, the total water-holding capacity of all these water bodies is estimated to be as much as 57% (1140 million cubic metres) of the total surface water runoff of the basin. In spite of such a large water-holding capacity within these tals and ponds/ tanks, floods are still an almost annual phenomenon in the Varuna basin because (i) water is not allowed to accumulate in the tals and (ii)the ponds/tanks have shrunk and/or silted up, reducing their volume. Deepening by desilting of tals and ponds/tanks can be taken up by engaging the local labourers through the government-funded rural employment guarantee schemes. The majority of the village tals and ponds/tanks can be used for pisciculture in order to generate development funds.

Characterizing interactive compound flood drivers in the Pearl River Estuary: A case study of Typhoon Hato (2017)

Tropical cyclone (TC) induced compound floods involve dynamic interactions among astronomical tides, storm surges, precipitation, and associated river pulses. This study employs a one-way coupled WRF, Delft3D, and HEC-RAS model to investigate the impacts of oceanic, pluvial, and fluvial processes on compound flood dynamics during Typhoon Hato (2017) in the Pearl River Estuary (PRE), South China. Total water levels driven by different combinations of flood drivers are modeled and analyzed. Relative contributions of each type of flood driver are quantified and used to categorize flood zones. This study highlights the persistent impacts of storm surges and their nonlinear interactions with other flood drivers. They can modify both the timing and magnitude of maximum water levels, thereby distorting tidal signals and contributing to post-TC landfall water level peaks. Along coastal regions, water levels exhibit three successive peaks, predominantly driven by storm surge, rainfall, and the combined actions of both factors, respectively. In upstream regions and coastal areas sheltered from islands, a singular water level peak arises exclusively from rainfall-runoff processes. Moreover, nonlinear interactions between surge and rainfall-runoff have non-negligible impacts on the relative contribution of individual flood drivers, which underscores the necessity of considering both rainfall and storm surge in modeling compound flood water levels. During the flooding period, peak storm surge and the following peak rainfall resulted in a time-varying distribution of flood zones. Alternating feedback between compounded and ocean-dominant areas manifests in the midsections of the upper PRE. Maximum flooding depth, extent, and duration are mainly influenced by rainfall. Storm surges play a secondary role, causing intense but short-lived flooding in coastal regions. These findings aid in understanding the generation mechanism of compound floods and provide references for hazard mitigation strategies.

Tectonics and climate controlled sedimentary provenance in the teesta basin since mid-holocene

Erosion of the Himalaya Mountain and subsequent deposition of sediments in the flood plains, and distal fans are primarily regulated by tectonics, climates, lithology, and relief of the region. These eroded sediments preserve their chemical and isotopic compositions in their depositional archive, which can be used to trace the erosion processes, assess the relative role of controlling factors and their spatio-temporal variations. The present study have analysed the 87Sr/86Sr and ԐNd of in silicate phase of sediment recovered from a ~ 40 m long sedimentary core representing ~8 ky of sediment accumulation in the Teesta River mega fan. The lithostratigraphy of the core indicates rapid aggradational nature of the Teesta mega fan. The 87Sr/86Sr and ԐNd display large variability with depth, which ranges from 0.75700 to 0.89294 and − 15.1 to −25.0, respectively. The observed 87Sr/86Sr and ԐNd values in the core sediments have been interpreted in terms of differential sediment contribution from the Higher and the Lesser Himalayan lithology. The 87Sr/86Sr and ԐNd isotope profiles and estimated fractional sediment contributions identify the Lesser Himalaya as the major sediment contributor to the Teesta basin since the mid-Holocene, unlike the other Himalayan River basins, dominated by sediments from the Higher Himalaya after the Last Glacial Maximum. The rapid exhumation and erosion of the tectonically active Rangeet window with the focused precipitation and presence of rock types vulnerable to weathering in the Lesser Himalaya of the basin appear to be the major factors resulting the sedimentary budget of the Teesta River basin over at least last 8 ky. Our assessment suggests that tectonic activity and climate have a competitive effect for the observed sedimentary budget, with an additional role of lithology. The study infers a major control of active tectonics, precipitation, and lithology on the sedimentary budget of the Himalayan River basins.

Footprint of soil erosion effects on pedodiversity at different hierarchical levels: A study across China's water erosion-prone areas.

Pedodiversity conservation is critical for the sustainable use of soil resources and the regulation of ecological security. To explore the relationship between pedodiversity and soil erosion over a prolonged history. In this paper, the response of the regional measurement factor for erosion (RMFE) to pedodiversity at different hierarchical levels was investigated using the optimal window method and structural equation modeling on the basis of water erosion-prone zones. The results suggest that variations in the factors used for soil classification at different hierarchical levels was the main cause of spatial heterogeneity in pedodiversity. Significant impacts of the RMFE on pedodiversity occurred mainly in the Middle reaches of Yangtze River low mountains, hills, plains and basins sub-region (IIC), the Southern China low mountains, hills and plains sub-region (IID) and the Southwestern Yunnan middle and high mountains sub-region (VE) at the Group, Subgroup and Genus levels. Notably, at the Subgroup and Genus levels, the impacts of soil erosion begin to be significant in the Wanda Mt and Sanjiang Plain low mountains and hills sub-region (IA), the Zhejiang and Fujian middle and low mountains, hills and valleys sub-region (IIA), and Taiwan plains and mountains of sub-region (IIE). The regional distribution revealed that pedodiversity in the southeast was more sensitive and positively correlated with the RMFE, with parent material, temperature and anthropogenic activities being the main influences. However, the negatively correlated effects of RMFE on pedodiversity were concentrated in the northeast, where the roles of parent material and vegetation were more critical. The findings of this study are of great practical value and scientific importance for the protection of soil ecological functions and the improvement of regional ecosystem quality and stability.

Confirmation of Nature of Palaeo-course of Assi River, India: Some Significant Revelations from Electrical Resistivity Tomography

ABSTRACT A long and continuous palaeo-course of Assi River, in between Prayagraj and Varanasi, in the Ganga River plains with indications of good groundwater potential had been traced from remote sensing data. Electrical Resistivity Tomography (ERT) has been conducted along eight lines for confirmation of the same palaeo-course in general and to specifically ascertain the nature of the course—the past flow conditions and the type of deposits. The variation in the thickness of channel deposits along the concave and convex banks and the middle parts is an indication of lean flow. The mixed fractions of channel deposits are an indication of dumping of sediments in the dying stages of a river. The ERT investigation has further helped in delineating the high resistive palaeo-channels (20 to 50 Ohm.m), the low resistivity aquiclude clay layer (<15 Ohm.m) and the deeper and relatively higher resistivity sandy layer (>50 Ohm.m), which could be the principal aquifer in the area.

Modelling and spatial prediction of earthworms ecological-categories distribution reveal their habitat and environmental preferences

Earthworms are one of the important soil animals and have been generally described as soil engineers. Knowledge on environmental conditions driving the distribution and population of this soil animal and the habitat which support these conditions especially at the ecological level is required to understand their responses to these environmental conditions at different habitats so as to guide its usage as bio indicator of soil quality and health. In this study we use RandomForest (RF), a machine learning algorithm to model species distribution, density/abundance based (SDM/SAM) and predict the biodiversity distribution (richness and density, ind.m−2) of three basic earthworms ecological categories: epigeic, endogeic and anecic (including the epi-anecic subcategory) across soil and climate variables at multiple habitat type/land uses in Germany. Our study shows there are spatial/ geographic variation in the distribution of the species richness and density among the three earthworms’ ecological categories. Also their environmental and habitat preferences are equally different, while epigeic species are predicted to be climate driven mostly in forests, endogeics are predicted to be the most diverse (in richness and density), but are mostly driven by soil textural contents (clay and silt) and found primarily in arable and grassland. Vineyard and crop flood plain are predicted to be suitable and the preferred habitat for anecics/epi-anecics. This study also identify optimum environmental gradient at which the species density is at the peak in each of the earthworm’s ecological category which would not only provide guide on soil biodiversity monitoring but also the soil health status.

Traditional Fish Hole Aquaculture System in Benin: Status, Challenges, and Research Prospects for Sustainable Development in Climate Change Mitigation

Fish holes called “whédos” are excavations performed near water bodies or in the flood plains of Beninese rivers in Africa for rearing fish. During floods, they are filled and naturally colonized by various fish that remain trapped during recessions. This literature review examines fishing, aquaculture, and fish reared in traditional holes in Benin. It reports on cartography, characterization, socioeconomic aspects, challenges, and status of improvement, and proposes prospects for improving this system. Peer reviews and gray literature were used to conduct the analysis. Our review highlights 19 papers reporting on 17 whédos aquaculture experiences based on the exclusion or inclusion criteria. These results indicate that many genera can be reared in whédos, suggesting that whédos offer the possibility of going beyond the production of Clarias and Tilapia in Africa. Furthermore, the exploitation of the whédos system is fairly profitable for fishermen and their households, at approximately US$ 1713 per household annually, used to finance agricultural activities, children’s education, schooling, mitigating farmers’ vulnerability to climate risks, and health care. However, in the past two decades, there has been a significant decline in the quantity of fish collected owing to the adverse effects of hydroclimatic changes, such as floods and prolonged droughts. Moreover, water eutrophication or pollution, the risk of climate change, and fishing methods have affected crop yield over the years. The implementation of Integrated Multi-Trophic Aquaculture or Integration Agriculture-Aquaculture in whédos systems can be an effective solution for improving profitability and sustainability. The knowledge gained from this review perspective should be helpful in directing future initiatives to grow and sustain this sector of the economy and to optimize its potential to provide food for future generations.

The development of flood zones

As cities develop, more and more areas are occupied by buildings and transportation infrastructure. It is only natural that urban development requires the creation of recreational infrastructure for city residents. Recreational infrastructure is essential for the proper functioning of city dwellers. Providing land for such infrastructure falls under the responsibility of local authorities. However, acquiring such land in large cities is very expensive. Therefore, areas with development restrictions become a natural space for recreational facilities. For this reason, the use of river valleys has been studied. These areas are currently used as floodplains in case of floods. The presented analyses were carried out for the city of Sandomierz. It is one of the oldest cities in Poland. The unique character of this city attracts many tourists each year. Most tourist attractions are located near the Old Town. The Old Town of Sandomierz is situated on the banks of the Vistula River. The Vistula River is the largest river in Poland. During floods it swells and the water overflows its bed. in order to protect residents from flooding, flood zones are designated, and flood embankments are constructed. Floodplains in this area occupy a significant part of the city. The research involved both geospatial and legal documentation analyses of this area. The paper proposes alternative ways of using these areas, taking into account the interests of city residents, municipal authorities, the natural environment, and institutions dealing with flood protection.

Study on Ozone and Its Critical Influencing Factors in Key Regions of China

Solar radiation is the fundamental energy source of climate change, which has a significant impact on the generations of secondary fine particulate matter (PM2.5) and ozone (O3) in the atmosphere. Additionally, surface solar radiation is also affected by the concentration of PM2.5, which in turn affects the generation of O3. To clarify the relationships among the O3, PM2.5 and the total radiation intensity, this study analyzes their temporal and spatial variation trends from 2017 to 2019. Meanwhile, as a common precursor of O3 and PM2.5, concentration variations in nitrogen dioxide (NO2) are discussed as well in this study. The results showed the following: (1) There are significant positive correlations between the O3-8h concentrations and the total radiation intensities in critical regions, especially in the “2 + 26” cities, Fen-Wei Plain and Yangtze River Delta. (2) The decrease in PM2.5 concentrations is in good agreement with the trend of NO2 concentrations, while the response of O3 concentration to the NO2 concentration variation differs in different regions, except in the Pearl River Delta. (3) In addition to the meteorological factors, changes in the concentrations and ratios of precursors such as NO2 and volatile organic compounds (VOCs) likely contribute to the observed fluctuations in O3 concentrations in recent years.

The post-depositional evolution of mesoproterozoic to early neoproterozoic tight sandstone reservoirs, São Francisco basin, Brazil

This study presents the first comprehensive assessment of unconventional gas reservoirs in the Proterozoic sequences of the intracratonic São Francisco basin, providing depositional and post-depositional characterization and insights into reservoir quality. Detailed stratigraphic, petrological, and seismic analyses, integrated with 2D seismic data, were performed to evaluate the influence of diagenesis and hydrothermal fluids. The drill core was drilled in the central sector of the basin and within the southern border of the Pirapora aulacogen, in a 303 m-thick interval of the Paranoá-Upper Espinhaço sequence. The petrological analysis shows arkoses and sublitharenites as well as conglomerates, siltstones and mudstones successions deposited in deltaic, fluvial braided and marine depositional systems. Six sedimentary environments were identified, from the base to the top: (i) deltaic plain, (ii) delta front, (iii) braided fluvial, (iv) delta front, (v) prodelta and (vi) basin plain. The integration of seismic data review three depositional domains, characterized by lower frequency arranged to transgressive-regressive cycles identified by gamma ray, resistivity and density logs. The studied strata review eo - and mesodiagenetic alterations, being also influenced by intrusion-related hydrothermal and contact metamorphism. The main diagenetic events resulted in cementation of calcite (0.84%), chlorite (1.23%) and silica (6.19%), which largely obliterated porosity at the shallow burial depths. The main secondary porosity is intergranular, with minor contributions to intragranular, fracture, moldic and vugular. Diagenetic processes as well as the influence of hydrothermal processes highlight the complexity of post-depositional processes in these units. The presence of natural helium and hydrogen within the basin also suggests that these reservoirs should be considered in future exploration campaigns targeting unconventional energy resources.

Chemical fractions of potassium in arid region calcareous soils: The impact of microclimates and physiographic variability.

Factors such as topography, mineralogy, physicochemical properties, and climate can affect the distribution of soil potassium (K) forms. However, often the special effects of physiographic units are neglected. Therefore, this study aimed to investigate the factors controlling the distribution of chemical fractions of K in different physiographic units of calcareous soils (piedmont plain, flood plain, alluvial plain, lowland, badland, and plateau) in southern Iran. The XRD analyzing patterns showed that the distribution of K forms is controlled by K-bearing minerals (i.e., illite) in finer particles of the soils. Physiographic units significantly affect the distribution of K forms due to different microclimates (such as soluble, exchangeable, and non-exchangeable). In addition, different correlations between the K forms and some physicochemical properties of the soils such as soil texture (i.e., silt (r = 0.511** to 0.527**) and sand (r = -0.357* to -0.389*)), electrical conductivity (EC) (r = 0.617** to 0.723**), sodium absorption ratio (SAR) (r = 0.478** to 0.577**), pH (r = 0.347* to 0.519**), and gypsum (r = 0.372* to 0.475**) were found in soils of the study area. It is recommended that cultivation sites are chosen with a deeper understanding of land conditions e.g., slope, elevation, microclimatic conditions, soil development, and clay mineralogy.

Pollution Characteristics and Eutrophication Assessment in Plain River Network Areas: A Case Study of the Beijing–Hangzhou Grand Canal (Changzhou Section)

Pollution Characteristics and Eutrophication Assessment in Plain River Network Areas: A Case Study of the Beijing–Hangzhou Grand Canal (Changzhou Section)

Optimum flood inundation mapping in mountainous regions using Sentinel-1 data and a GIS-based multi-criteria approach: a case study of Tlawng river basin, Mizoram, India.

Floods pose a significant global threat, impacting populations and infrastructure worldwide. However, mapping flood inundation solely with SAR data faces challenges in hilly terrain. To address this, the study integrates SAR data with a GIS-based multi-criteria approach (MCA), incorporating various indices and parameters, to enhance the accuracy of identifying potential flood zones. The findings demonstrate the effectiveness of this approach, with high accuracy validated using GPS data and a physics-based 3-step method. The results also indicate a high level of accuracy, with an area under the curve (AUC) value of 0.92 when comparing Sentinel-1 SAR and optical data during the process of extracting permanent water bodies. The Sentinel-1 SAR-derived flood extent was found to be 9.56m horizontally distant from the observed maximum flood mark, while the physics-based 3-step approach estimated the inundation extent to be 9.28m away. However, both methods accurately matched the vertical elevation of 40m above mean sea level (MSL). The findings underscore the effectiveness of SAR data and GIS-based MCA in monitoring and mapping floods in challenging terrains, offering practical implications for flood management strategies in Tlawng river basin.

A TÁJHASZNÁLAT ÉS TÁJGAZDÁLKODÁS VÁLTOZÁSA A MAROSSZÖGBEN (18– 19. SZÁZAD)

Nowadays, 35 independent settlements are located on the Marosszög floodplain, exploiting the opportunities provided by the microrelief. The region’s ecological properties and resources available to society, which change over time, and its natural and landscape characteristics were markedly different from the historical counties of Csongrád and Csanád, and in certain elements the Bánság and also from other regions of the former Torontál county. Marosszö can be divided into several parts from a landscape-geographical point of view, and as a result of the surface development, it has a threefold geomorphological division. The highest areas (88–96 m) are late pleistocene loess-sand free areas. The old holocene high flood plain is located in a lower surface position (82–87 m), while the new holocene low flood plain is located at the deepest level (77–81 m). Starting from the 18th century, in the reorganization process of economic life, mixed (polyculture) farming became dominant, characteristic of the settlement group as a whole. Until the start of the integrated environmental transformation works, society adapted, and its landscape-shaping and environment-transforming activities were only at the local level. The integrated environmental transformation works strongly changed the geographical foundations of social production and the ecological conditions, the former floodplain habitats, floodplain landscapes and habitats, which corresponded to the way of life of livestock keepers and farmers, disappeared. The use of landscape and resources changed and developed significantly, arable farming became dominant. The nature of agricultural activity has shifted towards crop production in fields and animal husbandry in stables.

Geospatial Capacity Building for Flood Resilience in the Sahel: the SLAPIS project case study

Abstract. This study focuses on the development of a people-centred early warning system (EWS) against floods in the Sirba River basin between Niger and Burkina Faso. This densely populated area has witnessed an increase in extreme flooding events in recent years. Several flood forecasting systems in the Sahel exist, although there is no EWS that integrates the four components of people-centred EWSs, namely risk knowledge, monitoring and warning service, dissemination and communication, and response capacity. The proposed EWS, named SLAPIS, includes a risk knowledge component that involves defining four levels of vigilance. Its monitoring and alert component involves a user-friendly web application containing real-time data collected through automatic stations. The EWS communicate seamlessly with the national alert system. The response capacity is strengthened through the creation of a flood zone atlas. In this framework, the EWS integrates significant geoinformatics in preparation of local risk reduction plans and the awareness of local communities. In the SLAPIS case study, multi-temporal classifications were conducted using Sentinel-2 data and high-resolution images (approximately 10 cm) generated through Structure from Motion (SfM) techniques. Digital Terrain Model (DTM) creation for hydraulic model calibration employed a multiscale approach, incorporating GNSS survey data processed via Precise Point Positioning (PPP), HydroSHEDS (approximately 100m resolution), and commercial 10m resolution data. All information was calibrated, harmonised, and integrated into the EWS model, which is accessible via a web platform. Capacity building encompassed direct training and field implementation to streamline the primary EWS generation steps.