scholarly journals Applying floodplain geomorphology to flood management (The Lower Vistula River upstream from Plock, Poland)

2020 ◽  
Vol 12 (1) ◽  
pp. 1003-1016
Author(s):  
Grzegorz Wierzbicki ◽  
Piotr Ostrowski ◽  
Tomasz Falkowski

AbstractUsing remote sensing extended on geological and topographical maps and verified by the field work, we present the flood management and study the geomorphic features of the floodplain of a large, sand bed, untrained but embanked river in order to determine the flood hazard and to predict future flood scenarios. In geomorphological mapping, we focus on the landforms: crevasse channels and splays, flood basin, chute channels, side arms, floodplain channels, dunes and fields of aeolian sand. We base the flood risk assessment on consultations with environmental engineers who design new technical structures that control inundation (cut-off walls and lattice levees). We describe a levee breach as a result of piping (inner erosion) in a high hydraulic gradient condition and its effect (scour hole) as an erosional landform consistent with the repetitive pattern of erosion and deposition formed by an overbank flow on a floodplain. We reveal an existence of homogenous morphodynamic reaches in the river valley.

2018 ◽  
Vol 18 (11) ◽  
pp. 2859-2876 ◽  
Author(s):  
Nguyen Van Khanh Triet ◽  
Nguyen Viet Dung ◽  
Bruno Merz ◽  
Heiko Apel

Abstract. Flooding is an imminent natural hazard threatening most river deltas, e.g. the Mekong Delta. An appropriate flood management is thus required for a sustainable development of the often densely populated regions. Recently, the traditional event-based hazard control shifted towards a risk management approach in many regions, driven by intensive research leading to new legal regulation on flood management. However, a large-scale flood risk assessment does not exist for the Mekong Delta. Particularly, flood risk to paddy rice cultivation, the most important economic activity in the delta, has not been performed yet. Therefore, the present study was developed to provide the very first insight into delta-scale flood damages and risks to rice cultivation. The flood hazard was quantified by probabilistic flood hazard maps of the whole delta using a bivariate extreme value statistics, synthetic flood hydrographs, and a large-scale hydraulic model. The flood risk to paddy rice was then quantified considering cropping calendars, rice phenology, and harvest times based on a time series of enhanced vegetation index (EVI) derived from MODIS satellite data, and a published rice flood damage function. The proposed concept provided flood risk maps to paddy rice for the Mekong Delta in terms of expected annual damage. The presented concept can be used as a blueprint for regions facing similar problems due to its generic approach. Furthermore, the changes in flood risk to paddy rice caused by changes in land use currently under discussion in the Mekong Delta were estimated. Two land-use scenarios either intensifying or reducing rice cropping were considered, and the changes in risk were presented in spatially explicit flood risk maps. The basic risk maps could serve as guidance for the authorities to develop spatially explicit flood management and mitigation plans for the delta. The land-use change risk maps could further be used for adaptive risk management plans and as a basis for a cost–benefit of the discussed land-use change scenarios. Additionally, the damage and risks maps may support the recently initiated agricultural insurance programme in Vietnam.


2021 ◽  
Vol 26 (2) ◽  
pp. 183-193
Author(s):  
Desyta Ulfiana ◽  
Yudi Eko Windarto ◽  
Nurhadi Bashit ◽  
Novia Sari Ristianti

Klaten Regency is one of the regions that has a high level of flood vulnerability. The area of Klaten Regency which is huge and has diverse characteristics makes it difficult to determine an appropriate flood management model. Water Sensitive Urban Design (WSUD) is a model that focuses on handling water management problems with environmentally friendly infrastructure. Therefore, an analysis is carried out to determine the level of flood vulnerability and factors causing flooding to plan a WSUD design that is suitable for each sub-districts of Klaten Regency. The Analytical Hierarchy Process (AHP) and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) methods are used to help the analysis. Aspects used as criteria are rainfall, slope, soil type, geological conditions, and land use. Based on the analysis, it could be concluded that Klaten Regency has two sub-districts with high flood hazard category, 21 sub-districts with medium category, and three sub-districts with low category. Bayat and Cawas are sub-districts that have a high level of flood vulnerability category. Meanwhile, Kemalang, Karangnongko and Polanharjo are districts with a low level of flood vulnerability category. The main factors causing flooding in Klaten Regency are slope and land use.


Author(s):  
Eteh Desmond ◽  
Francis Emeka Egobueze ◽  
Francis Omonefe

Flood has been a serious hazard for the past decades in Nigeria at large. The incidence of 2012 and 2018 flood disaster in Yenagoa, Amassoma and other parts of the state have not been recover till date and the government is not consigned about the well been of the people. The major causes of the flood are attributed to increased rainfall and lack of drainages including dredging of rivers and disobeying of environmental law and infrastructure failure. Coastal Towns or communities are one of the most affected areas of flood and their farms and fishing implements were washed away by the floodwater in 2012 and 2018 in Bayelsa State. Flood management is needed for provision of time information so quick response can be done as soon as possible. Using SRTM data to produce digital elevation model and IDW Contour, the 3D model from ground data of Yenagoa metropolis using ArcGIS 10.6 to generate and analyze them. As a result of field survey, flood level calculation was made to classified flood hazard zones for migration, Agricultural Educational, and construction purpose such as land suitability. This was used in ascertaining the extent of the flooded area. The result reveals that an area of over 5.9888882km2 and riverine and coastal area is flooded, affecting more than 15 coastal and riverine communities. The finding also concludes that remote sensing data like SRTM data and Geospatial techniques seems effective in mapping and identifying areas prone to flooding. Therefore Remote sensing and Geospatial database should be established for proper flood mapping and the government should constantly dredge the area from time to time. 


2021 ◽  
Vol 13 (2) ◽  
pp. 254-264
Author(s):  
Nguyen DUNG ◽  
◽  
Dang MINH ◽  
Bui AN ◽  
Nguyen NGA ◽  
...  

Floods are considered to be one of the most costly natural hazards in the Lam river basin causing infrastructure damages as well as devastating the affected area and relatively high death toll. So prevention is necessary for shielding lives and properties. The flood management on the Lam River basin has been considering for many years to minimize damages caused by flooding. The flood hazard zoning map is one of the indispensable tools to provide information about hazard and risk levels in a particular area and to perform the necessary preventive and preparedness procedures. The multicriteria decision analysis based on geographic information systems is used to build a flood hazard map of the study area. The analytic hierarchy process is applied to extract the weights of six criteria affecting the areas where are prone to flooding hazards, including rainfall, slope, relative slope length, soil, land cover, and drainage density. The results showed in 91.32 % (20103.83 km2) of the basin located in the moderate hazard zones to very high hazard zones. Accordingly, this study also determined 4 vulnerability levels to agricultural land including low, medium, high, and very high. About 94% of the total area of agricultural land in the basin are classified into moderate to the very high hazard of flood vulnerability. The paper presents a method that allows flood risk areas in the Lam River basin to receive information about flood risks on a smartphone, making them more aware.


Geofizika ◽  
2020 ◽  
Vol 37 (1) ◽  
pp. 1-25
Author(s):  
Neslihan Beden ◽  
Aslı Ülke Keskin

Flooding is one of the most catastrophic events among the wide spectrum of natural disasters that impact human communities. The identification of floodprone areas and the probability of occurrence, or estimated return period, of flood events are fundamental to proper planning for flood management and minimization of the social and economic costs of flood damage. In this study, 1D/2D coupled flood models of the Mert River, which flows into the Black Sea at Samsun in north-central Turkey, were developed. Based on the flood modeling results, flood extent, flood depth and flood hazard maps for the river were produced and they showed that the study area is particularly flood prone, as evidenced by catastrophic flooding in 2012. Specifically, the estimated 100, 500 and 1000-year peak discharges would affect 184 ha, 262 ha and 304 ha, respectively, of the 1,200 ha study area. Hazard ratings for the areas expected to be affected are shown in the flood hazard maps generated. The results of this research can be used by local government agencies in Samsun for the development of policies, strategies and actions that would help minimize the social and economic impacts of flooding, especially adjacent to the downstream sections where there is intensive development on the flood plain.


Author(s):  
Jafet Andersson ◽  
Abdou Ali ◽  
Berit Arheimer ◽  
Louise Crochemore ◽  
Bode Gbobaniyi ◽  
...  

<p>Flooding is a rapidly growing concern in West Africa. Several floods have occurred in recent years with severe consequences including loss of lives and damaged infrastructure. Flooding is also projected to increase with climate change. Access to operational forecasts is a critical component in addressing these challenges. This study presents results from our joint efforts to co-design, co-adapt, and co-operate a short- and medium-term operational hydrological forecasting and alert pilot system for West Africa, within the FANFAR project (www.fanfar.eu).</p><p>The system has been co-developed through a cycle of workshops, training sessions, and expert exchanges involving representatives from hydrological services, emergency management agencies, river basin organisations, and expert agencies in 17 countries in West and Central Africa. Multi-criteria decision analysis was employed to clarify and prioritize system objectives and configurations. We found that the most highly prioritized objectives were: high accuracy, clear flood risk information, reliable access, and timely production and distribution of the information. Our agile development approach also provided ample opportunities to focus development efforts on the most highly prioritized components, and incorporate stakeholder feedback in the development process.</p><p>The system is built on an ICT cloud platform that employs a daily forecasting chain including meteorological reanalysis and forecasting, data assimilation of gauge observations and satellite altimetry, hydrological initialisation and forecasting, flood alert derivation, and distribution through e-mail, SMS, web visualisation and API. The system is designed to enable multiple configurations and integration of several information sources (e.g. different hydrological models, observations, flood hazard thresholds etc.). We present the system configurations, stakeholder-driven adaptations, challenges, and current forecast performance. To our knowledge, the FANFAR system constitutes a significant advancement toward the vision of achieving efficient flood management in West Africa.</p>


2018 ◽  
pp. 88-95

Gestión de Inundación por Caudales Máximos en la Subcuenca Baja de la Quebrada del Río Huaycoloro - Río Rímac Flood Management for Maximum Flows in the Lower Subbasin River Gorge Huaycoloro –  Rimác River Gina Quincho Universidad Nacional Federico Villarreal, Lima, Perú DOI: https://doi.org/10.33017/RevECIPeru2014.0014/ Resumen El objetivo de la presente tesis es investigar la gestión de inundación por caudales máximos en la subcuenca baja de la quebrada del río Huaycoloro, con la finalidad de contribuir a mejorar la calidad de vida de los centros poblados como Cajamarquilla, Jicamarca y Huachipa; está investigación se ha estructurado en 4 capítulos. El primer capítulo desarrolla la problemática, los objetivos, la hipótesis que se muestran con sus respectivas variables y se justifica su relevancia y la importancia de esta investigación. En el segundo capítulo se muestra el marco conceptual y el marco normativo ambiental que sustenta los criterios y toma de decisiones para las propuestas de conservación y defensas rivereñas. En el tercer capítulo se describe la metodología utilizada por cada objetivo planteado, asimismo se detalla el tipo de investigación y métodos, los materiales y equipos; etapas en la realización del presente estudio. El cuarto capítulo, describe el diagnóstico ambiental de la Subcuenca Huaycoloro, que tiene un área 492.9 km2 y la longitud del río principal  es de 49.7 km, las características morfológicas le dan un área mayor en porcentaje de 54 % (colina y montaña – vertiente montañosa empinada a escarpada); se presentan 3 climas de un semiseco a un árido deficiente de lluvias; en su geología presenta  predominancia de rocas ígneas;  así mismo  en las características  socio económicas resalta que 38,436 habitantes que equivale al 60% de pobreza extrema; la precipitación máxima en 24 horas de la subcuenca varia de 5 mm hasta 30 mm, se estimó el caudal máximo dando como resultado para un periodo de retorno, para 10 años de 75 m3/s, para 50 años 104 y finalmente para 100 años 120 m3/s. Asimismo, se establece los criterios para la gestión de riesgos en la cual comprende el análisis peligros y vulnerabilidad, identificando el riesgo en zonas inundables que para 50 años le corresponden 37 ha de inundación en el tramo crítico. Finalmente se desarrollan los tipos de propuestas de conservación en suelos inundados y erosionados como medidas estructurales (gaviones, llantas), y no estructurales (agroforestería) con la finalidad de mitigar daños por desborde en la Subcuenca. Descriptores: Gestión, inundación, peligro, vulnerabilidad, riesgo, gaviones, agroforestería. Abstract The objective of this thesis is to investigate the management of flood peak flows in the lower subbasin Gulch Huaycoloro river, in order to help improve the quality of life of the towns as Cajamarquilla Jicamarca and Huachipa, this research is structured in 4 chapters. The first chapter develops the problem, objectives; hypotheses are shown with their respective variables and justify their relevance and importance of this research.  In the second chapter the conceptual framework and the environmental regulatory framework that supports the decision-making criteria and proposals for conservation and riverine defenses shown.  In the third chapter the methodology used for each objective proposed is described, also the type of research and methods, materials and equipment is detailed, steps in conducting this study. The fourth chapter describes the environmental diagnosis of Huaycoloro subwatershed, which has a 492.9 km2 area and length of the main river is 49.7 km, the morphological features give you a greater area percentage of 54 % (hill and mountain - Mountain slope steep to steep) 3 climates presents a semi- arid to poor rains, in geology presents predominance of igneous rocks, likewise in the socio economic characteristics highlights that 38,436 inhabitants equivalent to 60 % of extreme poverty; precipitation maximum within 24 hours of various sub from 5 mm to 30 mm , the maximum flow resulting to a return period to 10 years of 75 m3 / s , for 50 years and eventually 104 to 100 years 120 m3 / estimated s . Also, the criteria for risk management which includes the hazards and vulnerability analysis, identifying risk in flood zones that correspond to 50 years has 37 critical flood stage is set. Keywords: Management, flood hazard, vulnerability, risk, gabions, agroforestry.


2020 ◽  
Vol 2 ◽  
pp. 1-1
Author(s):  
E. Lynn Usery

Abstract. The U.S Geological Survey is exploring the use of machine learning and geospatial artificial intelligence (GeoAI) for topographic mapping tasks. These automated tasks include extracting topographic features such as hydrography, transportation, vegetation canopy, urban 3D structures, and others from raw data including lidar point clouds, color and near infrared images, historic topographic maps, and Web sources of existing geospatial resources. Current (2020) work includes extracting hydrography from elevation data, and geomorphic features with geographic names from historical topographical maps using Deep Learning. Extracted features are included in a geographic information system (GIS), supporting topographic mapping and modeling activities, and as semantic entities in a graph data model, building a knowledge graph for topographic data. These GIS datasets and topographic knowledge graphs can be used in automated topographic mapping processes and artificial intelligence routines that develop data for hydrologic, biologic, and geologic models that form part of the USGS EarthMap vision.


2017 ◽  
Vol 13 (32) ◽  
pp. 235
Author(s):  
Luc O. Sintondji ◽  
Elliott R. Dossou-Yovo ◽  
Donald Akogou ◽  
Euloge K. Agbossou

Flood is a natural disaster and causes loss of life and property destruction. Its impacts are large on agriculture especially in West African countries where smallholder farmers account for 80% of all the farms. The objective of this study was to assess flood risks in the inland valley of Dosir located in the district of Pélébina, northern Benin. Rainfall, discharge and water level in the riverbed were monitored using rain gauge, acoustic current meter and pressure sensors, respectively. The hydrological functioning of the inland valley was simulated using the Integrated Flood Analysis System (IFAS) model. The calibration was done based on the land use map (GlobalMap) and the soil water holding capacity map (UNEP). Our study demonstrated the existence of a high flood hazard in the inland valley of Dosir which reacts very quickly to rainfall solicitations. The IFAS model has shown a good performance in simulating the runoff in the riverbed of the inland valley with a coefficient of determination of 0.65. The IFAS model can be used to design a flood management system in the district of Pelebina. Further studies are needed to assess the exposure and vulnerability of farmers to flood risk.


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