Riverbank Erosion

Puji syukur kami panjatkan kehadirat Tuhan Yang Maha Esa, yang telah memberikan kesehatan jasmani dan rohani serta petunjuk dan kekuatan kepada penulis sehingga makalah yang diberi judul "Strategi Adaptasi dan Mitigasi Terhadap Perubahan Iklim di DAS Brantas" bisa diselesaikan. Meskipun masih terdapat banyak kekurangan di dalam makalah ini, kami berharap kami bisa mendapat timbal balik berupa kritik dan saran sehingga kami bisa menjadi lebih baik lagi untuk kedepannya Adapun tujuan dari penyusunan makalah ini, yaitu sebagai pemenuhan Evaluasi IV dari mata kuliah Perencanaan Wilayah. Evaluasi tersebut bertujuan untuk meningkatkan kemampuan mahasiswa dalam mengidentifikasi persoalan pengembangan wilayah, berikut dengan upayaupaya untuk menangani permasalahan yang telah diidentifikasi. Permasalahan yang diangkat dalam makalah ini memiliki tema perubahan iklim yang merupakan salah satu materi dalam mata kuliah Perencanaan Wilayah.

Bangladesh is a low lying riverine country formed by a deltaic plain at the confluence of the three mighty rivers Ganges, Brahmaputra, Meghna and their tributaries. Most of the flows of these major rivers are connected to the Bay of Bengal through Meghna Esuary. The Lower Meghna River with a very dynamic estuarine system conveys the maximum flow through the estuary to the Bay of Bengal during dry and wet season . The sediment load and flow volume in Lower Meghna is respectively the highest and the third highest (after Amazon and Congo) in the world (Ahmed S. 1998). Owing to this tremendous water volume and sediment load delivered by the rivers, the estuary is an area of an active land erosion-accretion and dynamic water circulation. The main physical processes in the estuary are mainly dependent on the estuarine morpho-dynamics that causes erosion and accretion in the scale of hundred sq. kilometers per year and cause several thousands of people to become landless and homeless every year (Biswajit et al., 2013) 2000-2013. Net accretion, net erosion and the erosion trend are derived from the image processed using ILWIS 3.7.2 and ArcMAP 10. It is obvious that the erosion rate was in decreasing order from the year 1973 to 1984, 3.4km2/yr to -8.4km2/yr. Analysis also showed that in the history of the last forty years erosion rate was higher from the year 2003 to 2005, -8.4km2/yr to 15.4km2/yr. Recent year analysis predicted that the deposition is higher than the erosion. However, further research should be focused on future channel shifting pattern, erosion rate and vulnerability of different locations as well as determining effective measures to decrease erosion severity and its consequences.

One of the life-changing consequences (of floods and erosion in Assam) is Displacement. This results not only in loss of livelihoods but also has wide-reaching socio-economic and cultural effects. Thus, due to such disasters not only families but communities too are being displaced at large. This compels them to find temporary shelter and begin life from scratch. The role of the state has been highly negligible, with displacement not being perceived as an ‘issue’ to be addressed. A more holistic approach is thus needed to take socio-economic, cultural, political as well as ecological considerations into account.

Varios son los factores que definen y controlan la erosión intensa y acelerada en Bánica, en la margen izquierda del río Artibonito y del lado Dominicano de la frontera con Haití. Durante el Cuaternario, se ha desarrollado un rejuvenecimiento del ciclo geomorfológico de erosión, relacionado tal vez con un levantamiento regional de origen tectónico. Los ríos ejecutan la erosión de sus depósitos aun recientemente sedimentados y sin consolidar. Contra un proceso natural de esta clase, muy poco puede hacerse para evitar o disminuir sus implacables, aunque lentas, consecuencias. Por otra parte, la actividad humana, responsable de la destrucción casi total y generalizada de los bosques y casi todo otro tipo de cobertura vegetal, ha provocado una ruptura del frágil equilibrio y generado un daño difícilmente recuperable al ambiente. Una vez eliminada la cobertura vegetal del suelo, ya sea por deforestación,
sobrepastoreo o por las prácticas inapropiadas de explotación agraria, pues no se practica ningún tipo de medida de conservación de suelos, las lluvias locales, de elevada intensidad (aunque de promedios anuales modestos), activan la erosión eliminando las capas húmicas y otras subyacentes, evitando cualquier posible recuperación espontanea. Como resultado, toda el área tiene indicios de erosión laminar y concentrada, con varios casos particulares y extremes en donde se presentan zanjas, cárcavas, cañadas y "tierras malas" de desarrollo total. Tomando pues en cuenta el desarrollo actual del proceso, es evidente la necesidad de tomar decisiones inmediatas dirigidas al establecimiento de dispositivos de control de la erosión que incluyan componentes vegetativos (pastos, barreras vegetales, reforestación) y físicos (terrazas, pedraplenes, gaviones). No debe, sin embargo, olvidarse que aun y cuando este tipo de medidas de control sean correctamente diseñadas y aplicadas en el tiempo y en el espacio, no siempre ofrecen un rendimiento óptimo de funcionamiento y, por lo tanto, no necesariamente son soluciones totales ni ideales. En tales circunstancias, deben analizarse y compararse los costos de esas medidas con los de la infraestructura a proteger y aun con la posibilidad de una reubicación del poblado. Es pues evidente la necesidad de un estudio multidisciplinario e integral en el que también los parámetros socio-culturales deberán tener una prioridad bien establecida.

This article addresses how gender norms impact the process of migration, and what this means for the use of migration as an adaptation strategy to cope with environmental stressors. Data was collected through qualitative fieldwork, taking the form of semi-structured and open-ended interviews and focus group discussions from a Dhaka slum and three villages in Southern Bangladesh's Bhola district. Our data revealed that women migrate when environmental stress threatens livelihoods and leave male household members unable to earn enough income for their families. Employing an analytical framework that focuses on the perceptions of individuals, this article shows how gender norms create social costs for women who migrate. Women thus have ambivalent feelings about migration. On the one hand, they do not wish to migrate, taking on a double work load, forsaking their purdah, and facing the stigma that follows. On the other hand, women see migration as a means to help their families, and live a better life. While social costs negatively affect the utilization and efficiency of female migration as an adaptation strategy to environmental stressors, it becomes clear that female migration is imperative to sustain livelihoods within the Bhola community.

In the Crescentino-Verrua savoia area, the Po river represents the most important idrographic element, forming with the Dora Baltea river an hidraulic node of interregional importance, with an extreme mobility of the confluenze and with a 13000 sqlm river basin. After the floods of 1994 and 2000 this area has been affected by many defence works agaist floods and erosions.

Bangladesh is one of the most vulnerable countries to climate change. Due to the geographical location and being a riverine country, it faces various natural disasters. Migration has become an adaptation and survival strategy when natural disasters strike and peoples’ livelihoods are damaged or threatened. Black et al. (2013) predicted that in Bangladesh alone, 26 million people would be likely to be displaced by 2050 as a result of floods and storms induced by climate change. In coastal and river bank regions, poor citizens rely on government support and assistance after losing their livelihoods. The Bangladeshi local government’s lowest tier Union Parishad is closest to the poor and vulnerable people. Union Parishad is the only service delivery institution in Bangladesh where impoverished people can easily access help and support. But historically, the Union Parishad has not provided adequate support to the vulnerable citizens during natural disasters. This research aims to support climate migrants and locally resettled victims of climate change by applying the Union Parishad budgetary intervention. Participatory Budgeting is a very successful method to establish financial democracy. The Brazilian intervention has been widely exported from Latin America all over the globe. This process is exceedingly beneficial to citizens as it requires their participation and involvement in the budget planning and formulation process. Thus, the budget is people-oriented. Since Bangladesh’s budget figures are hidden within unseen documents, the introduction of Participatory Budgeting within the Union Parishad budget cycle will allow the figures to be more transparent. This research paper also reveals how the Participatory Budgeting process will have an active role in reducing climate migration through the efforts of the Union Parishad and its citizen’s active participation. The study attempts to understand this topic and tries to establish Participatory Budgeting in Bangladesh in order to reduce poverty and climate migration.

Spatio-temporal analysis of Kilim River using Very High-Resolution (VHR) satellite image between the years of 2005 and 2012 are vital to assess river morphological changes and erosion detection over the specific time duration. Therefore, this study utilizes remote sensing and Geographical Information System (GIS) capabilities to identify the channel migration and shifting as well as to calculate the rate of erosion and accretion. Classification of the river from Quickbird and WorldView-2 images is carry out using Maximum Likelihood Classification (MLC) technique whereas feature selection tool performs to extract river feature from the raw image. Subsequently, river feature been overlaid to identify the changes of riverbank pattern and to calculate the rate of riverbank erosion in terms of area. The result shows the total area of erosion is 27252.959 m 2 and the total area of accretion is 6079.999 m 2. A maximum erosion of 6993.102 m 2 detected at Section E while maximum accretion of 681.026 m 2 spotted at Section D. The rates of riverbank erosion are 3406.62 m 2 /year while the rates for accretion are 759.999 m 2 /years between 2005 and 2012. Hence, the output of this study enables Langkawi Development Authority (LADA) and other stakeholders to recognize the specific location, which severely affected by erosion and accretion as well as to spot the area experienced huge river channel shifting.

Settlements development on riverbank wetland degrades the performance of the ecosystem services function. The riverbank Wetland has important ecosystem services that should be conserved. However, in some cities, the development in this area is difficult to avoid. To reduce the damage to the ecosystem services, it is necessary to identify the ideal development according to the ecosystem approach. This study identifies the gap between the factual house type and the ideal type according to the ecosystem approach. The factual home types were identified through field observations, whereas the types of recommendations were identified based on an assessment of the experts. The results indicated that there was a gap of the house types between the factual and the recommendations. Therefore, the planning should adjust the house types between the factual and the recommendation of the ecosystem approach. The settlement planning that equilibrates the community needs and the sustainability of ecosystem services.

Abrupt climate changes represent a constant threat for monsoon regions, and affect the survival of entire populations. It was estimated that in 2015 the African monsoon known as “El Niño” was the most intense of the last decades (Ethiopia Humanitarian Country Team (EHTC) 2015, FAO 2016, Partnerships and Resource Mobilization Branch (PRMB) 2016). In the case of Ethiopia, the most severe consequence consists in the alteration of the annual rainy season. Periods when rainfall events occur become shorter and unsteady, resulting in short intense floods (Ethiopian National Meteorological Agency (NMA) 2016, Agriculture Knowledge, Learning, Documentation and Policy (AKLDP) 2016). In the city of Arba Minch the combination of intense precipitation events and improper land management have fostered the action of erosion, causing an irreversible modification of the environment. Human actions like deforestation, overgrazing and intensive cultivation contributed decisively to deteriorate the land, favoring the erosive process.
The project “Slope Farming Arba Minch” aims to reverse soil erosion using an integrated approach, which includes soil conservation methods, organic agricultural practices and Rain Water Harvesting measures (Wibbing 2016). A project site was destined to the project, to implement various conservation measures aimed to restore vegetative cover on arid areas. However, the area is positioned in the watershed of a gully system, which enlarges during rainy seasons due to the erosive processes (CLARA 2011). In October 2015, during the second Ethiopian rainy season, two check-dams were implemented to counteract erosion in the main gully. Although both structures appeared to be sufficiently robust to bear small and medium rain events, they eventually failed when a particularly intense flood occurred.
Hence, it was then decided to implement a series of check-dams that could be able to resist extreme floods. At first, a field survey of the catchment area related to the gully system was performed. The collected information was used to model the gully network and its watershed. Two different concepts of check-dam were used. A greater structure was constructed to accumulate sediments during various rainfall events, while three small step-dams were designed to be increased in different stages. All dams were performed using field materials and resources provided by the municipality of Arba Minch, and using local manpower support. The process of implementation took place at the end of the second annual rainy season, in December 2015. The check-dams were terminated at the end of January 2016, in order to be tested during the rainy season occurring in the spring of 2016. Daily rainfall amounts were observed from March 2016 and used as reference to assess the response of the check-dams to the first rainy season of the year.

Soil Erosion and siltation are serious environmental concerns nowadays. In tackling the problem, vegetation is the main sustainable and reliable solution. However, the type of species to be used for soil water conservation is depending on the socio-economic interest of the end users which necessitates the application of multicriteria based plant species selection to ensure community interests besides the erosion and siltation control.

This paper presents the results of a monitoring programme designed to investigate the inherent factors contributing to channel instability and riverbank erosion on the Iju River, Southwest Nigeria. Detailed reconnaissance surveys and in situ measurements were used to determine the geomorphometric characteristics of the riverbanks at more than 15 locations along the river channel. Laboratory tests in combination with the Bank Stability and Toe Erosion Model (BSTEM) and Bank Erosion Hazard Index (BEHI) were conducted to determine the shear strength characteristics and erosion potential of the riverbanks. The BSTEM results indicate that the factor of safety (FS) decreased from the initial values of 2.64 and 4.42 to 1.09 and 0.51, respectively. Further correlation of FS with root depth and depth of tension crack showed that FS was positively correlated with root depth but decreased with an increase in the depth of tension crack. The high BEHI values of 26 and 32 gave credence to the assumptions regarding the high erosion potential of the Iju riverbanks. These research findings are essential for the development of a watershed-scale natural disaster mitigation plan for the Southwest region of Nigeria.

Spatio-temporal analysis of Kilim River using Very High-Resolution (VHR) satellite image between the years of 2005 and 2012 are vital to assess river morphological changes and erosion detection over the specific time duration. Therefore, this study utilizes remote sensing and Geographical Information System (GIS) capabilities to identify the channel migration and shifting as well as to calculate the rate of erosion and accretion. Classification of the river from Quickbird and WorldView-2 images is carry out using Maximum Likelihood Classification (MLC) technique
whereas feature selection tool performs to extract river feature from the raw image. Subsequently, river feature been overlaid to identify the changes of riverbank pattern and to calculate the rate of
riverbank erosion in terms of area. The result shows the total area of erosion is 27252.959 m2 and the total area of accretion is 6079.999 m2. A maximum erosion of 6993.102 m2 detected at Section E while maximum accretion of 681.026 m2 spotted at Section D. The rates of riverbank erosion are 3406.62 m2 /year while the rates for accretion are 759.999 m2/years between 2005 and 2012. Hence, the output of this study enables Langkawi Development Authority (LADA) and other stakeholders to recognize the specific location, which severely affected by erosion and accretion as well as to spot the area experienced huge river channel shifting.

Riverbank erosion is a serious environmental issue which urges government to take appropriate action to solve this problem. Kilim River, Langkawi Geopark which is located at the northern part in Peninsular Malaysia is now under the threat of critical reduction caused by intensification of tourism activities. The purpose of this study is to assess riverbank erosion by using combination of geospatial techniques consist of high resolution imagery and unmanned aerial vehicle (UAV) approaches. Both images from UAV and Quickbird is rectify and process by using GIS and remote sensing software in order to determine the erosion area of river, based on Kilim River area comparison between 2005 until 2016. Subsequently, Empirical Bayesian Kriging (EBK) analysis become main option to predict riverbank erosion in future based on present erosion data by using interpolation method and the other method of interpolation is also used as the comparison. The finding shows that the Kilim River is changes during in between 2005 and 2016 due to several factors such as boat wakes and sea level rise (SLR). The area of Kilim River is increasing from 16.72 acres to 23.2 acres within eleven years and means that 6.48 acres of mangrove forest is eroded. 38% of mangrove riverbank in that area is considered of having erosion and deposit into the river. If it continuously happens, more area of mangrove forest will be eroded in the future. Interpolation of riverbank erosion in future indicates about more than 30 acres of mangrove riverbank erosion will be eroded for the next 10 years. For this study, perhaps the geospatial technologies are can be utilized in environmental study for detection of riverbank erosion.

Resumo Este estudo visou avaliar sazonalmente e espacialmente o silicato dissolvido nas águas superficiais de dois rios com características físicas similares, porém com diferentes níveis de interferências antropogênicas. Os resultados mostraram que em períodos de estiagem a água superficial de locais de baixa profundidade pode apresentar concentrações elevadas, demonstrando que a circulação estuarina é determinante nas flutuações deste nutriente na camada superficial, ainda que o mesmo seja abundante no ambiente. A sinalização de processos erosivos por este parâmetro é mais evidente em períodos chuvosos. Abstract This study aimed to evaluate seasonally and spatially the dissolved silicate in surface waters of two rivers with similar physical characteristics, but with different levels of anthropogenic interference. In dry season the surface water in shallow sites can represent high concentrations, proving that the estuarine circulation is very influential in the concentrations of dissolved silicate on surface. The dissolved silicate as an indicator of erosion becomes more evident during rainy periods.

Bangladesh is a low lying riverine country formed by a deltaic plain at the confluence of the three mighty rivers
Ganges, Brahmaputra, Meghna and their tributaries. Most of the flows of these major rivers are connected to
the Bay of Bengal through Meghna Esuary. The Lower Meghna River with a very dynamic estuarine  system
conveys the maximum flow through the estuary to the Bay of Bengal during dry and wet season (Rahman et al,
2013). The sediment load and flow volume in Lower Meghna is respectively the highest and the third highest
(after Amazon and Congo) in the world (Ahmed S. 1998). Owing to this tremendous water volume  and sediment
load delivered by the rivers, the estuary is an area of an active land erosion -accretion and dynamic water
circulation. The main physical processes in the estuary are mainly dependent on the estuarine morpho -dynamics
that causes erosion and accretion in the scale of hundred sq. kilometers per year and cause several thousands of
people to become landless and homeless every year (Biswajit et al., 2013). Chandpur district situated at Padma
and Upper Meghna confluence point in Meghna estuarine system is selected as the study area, since it is the
most vulnerable zone for erosion and accretion due to sediment load. In this study, the long term suffering due
to erosion, bank shifting characteristics and sand bar formation of the Meghna River has bee n unveiled. At first
a 1D model is set up for an average year to compute the yearly maximum and average discharge of Lower
Meghna River at Chadpur confluence. Then the erosion analysis has been done using high resolution of Landsat
satellite imagery (Band  4 to Band 7) from the year of 1973 to the year of 2010 and Google Earth image from
2000-2013. Net accretion, net erosion and the erosion trend are derived from the image processed using ILWIS
3.7.2 and ArcMAP 10. It is obvious that the erosion rate was in  decreasing order from the year 1973 to 1984,
3.4km2/yr to -8.4km2/yr. Analysis also showed that in the history of the last forty years erosion rate was higher
from the year 2003 to 2005,  -8.4km2/yr to 15.4km2/yr. Recent year analysis predicted that the deposition is
higher than the erosion. However, further research should be focused on future channel shifting pattern, erosion
rate and vulnerability of different locations as well as determining effective measures to decrease erosion
severity and its consequences.

Climate change impact like heavy rainfall in unscheduled time will likely cause significant changes in sediment and flood regimes of the river. For that reason in large rivers like the Jamuna may be disturbed and required a long time for adjustment in fluvial processes and morphological forms. Sudden water level rise, flooding and bank erosion of the river influence life and livelihood of the near bank people. Among different morphological changes, riverbank erosion is a common and frequent natural hazard for Jamuna. People lived near the river bank applied indigenous technique for erosion protection by using locally available materials. The objective of this study is to identify the indigenous erosion protection measures practiced by the local people on the context of climate change. Socio technical approaches were used for the study. Water level data, satellite image analysis associated with FGD, KII and house hold survey were conducted. It was found that people took defensive measures like bamboo pilling, sand filled bag dumping for erosion protection. Migration is also a measure taken by local people when they are already affected. For the effective erosion protection, massive engineering works are preferred. But local knowledge based protection measures are effective and sustainable in low water flow area where erosion is insignificant.

As Bangladesh is a land of river so she cannot but accept the river erosion. But due to many reasons the rate of river erosion is increasing day by day, so it has become a threat to many people. Riverbank erosion causes enormous and long-term socio-economic consequences. All Upazila are not well capable to serve their population. People of these upazila depend on the surrounding upazila to fulfill their needs. Generally, the population is high in the areas which offers more facilities to the people. This research evaluated the influence area of the individual upazila of three districts Gaibandha, Jamalpur and Sherpur. The influence area shows the upazila’s capability of serving the population. The objective of study is to define the influence areas of the regional centers and analyze the reasons behind the changes in ranking and find out the functional gap. The study analyzed education institutions, medical facility, flood camps or shelters, and river flow as the factors contributing to Upazila’s serving capabilities. In this context, 19 upazilas of Gaibandha, Jamalpur and Sherpur Districts have been brought under consideration based on population. The data are collected from Bangladesh Bureau of Statistics (BBS) and the study is based on the Retail Gravitation Analysis Method following Reilly’s Gravitational Theory for determining the influenced area which finally has been presented with a map prepared with Geographic Information System (GIS). The influence area delineation of the regional centers finds out the regional gap in between the polygons. Again, the analysis of the change in the ranking according to the influence area finds out the factors that create an impact on the influence area. This study indicates that the unserved areas cannot serve the people or residents during river erosion rather it creates a burden to the served areas. So, the local authority and government should take the necessary steps to solve this issue.

Spatio-temporal analysis of Kilim River using Very High-Resolution (VHR) satellite image between the years of 2005 and 2012 are vital to assess river morphological changes and erosion detection over the specific time duration. Therefore, this study utilizes remote sensing and Geographical Information System (GIS) capabilities to identify the channel migration and shifting as well as to calculate the rate of erosion and accretion. Classification of the river from Quickbird and WorldView-2 images is carry out using Maximum Likelihood Classification (MLC) technique whereas feature selection tool performs to extract river feature from the raw image. Subsequently, river feature been overlaid to identify the changes of riverbank pattern and to calculate the rate of riverbank erosion in terms of area. The result shows the total area of erosion is 27252.959 m2 and the total area of accretion is 6079.999 m2. A maximum erosion of 6993.102 m2 detected at Section E while maximum accretion of 68...

Riverbank erosion is a common natural disaster in Bangladesh. Bangladesh is located in the world’s largest active Ganges delta where GangesBrahmaputra-Meghna (G-B-M) river systems carry out enormous sediment load simultaneously extensive riverbank erosion is prominent to balance
river dynamics. Somewhere this equilibrium could be disturbed by human activities and leads to bank consumption. This study is on riverbank erosion
assessment of Sandha River at Rahmatpur and Dehergati unions in Babuganj upazila, as well as detection of the probable key factor to bank consumption caused by local human activities. Rapid establishment of a large number of unplanned brickfields along the riverside at the study area requires a huge amount of sediment as raw material, which are extracting from the river bed, point bars, flood plain and other riverine places. This excessive sediment
mining alters the local river morphology and imbalance the river dynamics over there. This study was carried out by conducting a questionnaire survey to collect primary data. The Remote Sensing (RS) method was used to collect and analyze satellite images. Geographic Information System (GIS) was applied
to prepare different models, maps and tables in the study area. In addition, Surfer software was also used to create contour maps and elevation profiles
of the study area. These models, maps and tables are showing the sharp changes of the river banks as well as the increasing number of brickfields at the study area since 2011. This unusual fluvial sediment excavation for commercial purposes from the riverside should be stopped immediately by effective surveillance of related authority along with proper distribution of accreted land among the affected local people is essential.

Degradasi atau penurunan kualitas lahan merupakan isu global utama pada abad ke-20 dan masih menjadi isu penting dalam agenda internasional pada abad ke-21. Erosi tanah, kelangkaan air, energi, dan keanekaragaman hayati menjadi permasalahan lingkungan global sejalan dengan meningkatnya jumlah penduduk. Erosi tanah menyebabkan degradasi lahan karena dapat menurunkan kualitas tanah serta produktivitas alami lahan pertanian dan ekosistem hutan.

Bangladesh frequently suffers from acute riverbank erosions and, as a result, every year a large number of people internally migrate to new places mainly in search of livelihoods. While very few studies focus on the multifaceted nature of vulnerability experienced from riverbank erosions, the present study examines to what extent different drivers of vulnerability affect socioeconomically disadvantaged internal migrants living in riverbank erosion-prone areas in Bangladesh. Empirical evidence from two northwestern riverbank erosion-prone districts in Bangladesh demonstrates that the disadvantaged internal migrants and their household members were exposed to a range of vulnerabilities connected to economic, institutional, infrastructural, environmental, and social drivers. It is contended that evidently there are different types of vulnerability some of which are perceived to be more severe than others in the study areas. This study, therefore, suggests extending some specific support programmes including income generation schemes, access to institutional credit for the landless, improved inexpensive means of transportation, and improved communication. This article also proposes improving rural infrastructure including irrigation facilities, inexpensive transportation means for agricultural inputs or other farming materials, reasonable prices for daily necessities, and improved health care benefits.

Cet article, présente des résultats préliminaires concernant l'étude de l'érosion des berges de l’oued Sebou en aval de de Fès, dans la zone du Prérif. L’étude s’est concentrée sur le sapement des berges favorisé par l’activité hydrodynamique, surtout aux moments des fortes crues. Ces dernières entraînent le recul des berges au niveau des concavités des méandres, pouvant varier entre 0,5 et 1, 4m. L’érosion peut aussi affecter le bas des versants marneux dominant le cours d’eau et déclencher des glissements des terrains. Cette dynamique implique une forte mobilité du chenal de l’oued Sebou dans sa plaine alluviale, comme nous l’avons montré d’après le suivi de l’évolution de son tracé durant les sept dernières décennies, entre 1943 et 2016. Cette mobilité a en effet de fortes conséquences sur les pertes des terres agricoles exploitées sur les sols de la plaine alluviale de la vallée du Sebou. Ce qui nécessite des interventions d’aménagement pour réduire les effets de cette érosion.
Mots clés : Moyen Sebou, sapement des berges, méandres, plaine alluviale, impact socio-spatial.

The Brahmaputra basin in India, particularly its valley in Assam, represents an acutely flood-prone region and occurrence of flood has been an age-old phenomenon in the riverine areas. During the rainy season, the rivers not only become filled up with water, but the excess amount of water also spill over their banks flooding their neighbouring regions. At the same time bank erosion occurs in almost all the large rivers destroying human habitats and their crop fields. The greatest single casualty due to recurrent floods, accounting for as much as 75 per cent of the total flood loss is the agricultural sector which happens to be the mainstay of the economy. Accelerated erosion due to deforestation and increased pressure on land due to explosion of population is a major cause of this increase in sediment yield. Biological means of protection against erosion are the cheap and simple practical solution that must be technically suitable for different conditions, economically viable with r...

In Bangladesh climate change has contributed to a massive displacement of people. This study examines the effects of climate-related displacement, socioeconomic status, availability of healthcare providers and disease-related attributes on the healthcare-seeking behaviors of parents for their children. Using cross-sectional survey data from the parents of 1003 children aged under 15 who were ill in the four weeks prior to the interview, collected from 600 randomly-selected households in climate displacement-susceptible areas and 600 households in non-climate-displacement-susceptible areas in Bangladesh, we use multivariate logistic regression to identify the factors associated with parental healthcare-seeking behaviors. The results show that 15.5% of the children who had been ill receive either no care or curative care at home. Of those receiving care outside the home, only 22.1% are treated by trained providers. Climate-related displaced parents are significantly less likely to seek care or to use provider-prescribed care to manage children's illnesses. Areas lacking local healthcare providers, poorer households, females, child age and mild illness are also associated with a child being significantly less likely to be treated outside the home. The children of climate-related displaced parents are around half as likely as those of non-displaced parents to be treated by a trained provider. The local availability of medical doctors, cost of reaching a healthcare center, household income, type and severity of illness, child's age, and joint parental decision-making about care providers are also important predictors of the selection of trained healthcare providers for children. Thus, climate-related displacement affects the healthcare-seeking behaviors of parents for their children. Policy aimed at improving child health should address the socioeconomic disadvantage and access to healthcare of the displaced, the training of local untrained providers about Primary Health Care service provision, and the numbers of medical doctors in the displacement-prone areas.

ABSTRACT This paper examines the experiences of people displaced internally by climate-related factors in mainland Bangladesh, one of the world's most climate-vulnerable countries. The data derives from a representative survey of 1,200 households drawn equally from displacement-susceptible areas and areas without climate-related displacement. Comparisons are drawn on the basis of four variables: the displaced versus the non-displaced; before displacement versus after displacement; people displaced suddenly versus those displaced gradually; and the frequency of past displacement. The displaced experience multiple disadvantages, including reduced land ownership and reduced access to electricity, sanitary toilets and healthcare services. The disadvantage is greater following sudden displacement and among those who have been displaced multiple times. The impact on the time and cost of accessing healthcare are greater after displacement. The disadvantage of the displaced, thus, is a function of interactions between exposure to natural disaster, impoverishment and lack of access to health services.

Sedimentation hazards pose several geoenvironmental problems in active alpine regions and fluvio-deltaic environments. Therefore, this research seeks quantitative knowledge of the mechanisms that trigger riverbank erosion which result in high volumes of sediment yield in the downstream reaches of the Nkisi River. Study of the mechanisms of mass wasting of the riverbanks was motivated by the high rate of siltation and accretion that are currently occurring at the mouth of the Nkisi River, occupying a total surface area of about 40,000 m 2. Many riverbank stability and erosion assessment studies have been done using a wide range of geomorphometric and geotechnical analyses which consider the shear strength of the bank materials in relation to the geomorphometric characteristics of the riverbanks. With this insight, this research focuses on investigating the potential causes of riverbank retreat on the river, with particular interest on the effects of soil properties in triggering mass failures. Field surveys and laboratory investigations, coupled with Bank Erosion Hazard Index (BEHI) and Bank Stability and Toe Erosion Model (BSTEM) characterized the riverbanks as unstable and conditionally stable, revealing a potentially high rate of sediment loading from the composite banks, with a factor of safety that varies from 0.76 to 1.04.

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In Bangladesh climate change has contributed to a massive displacement of people. This study examines the effects of climate-related displacement, socioeconomic status, availability of healthcare providers and disease-related attributes on the healthcare-seeking behaviors of parents for their children. Using cross-sectional survey data from the parents of 1003 children aged under 15 who were ill in the four weeks prior to the interview, collected from 600 randomly-selected households in climate displacement-susceptible areas and 600 households in non-climate-displacement-susceptible areas in Bangladesh, we use multivariate logistic regression to identify the factors associated with parental healthcare-seeking behaviors. The results show that 15.5% of the children who had been ill receive either no care or curative care at home. Of those receiving care outside the home, only 22.1% are treated by trained providers. Climate-related displaced parents are significantly less likely to seek care or to use provider-prescribed care to manage children's illnesses. Areas lacking local healthcare providers, poorer households, females, child age and mild illness are also associated with a child being significantly less likely to be treated outside the home. The children of climate-related displaced parents are around half as likely as those of non-displaced parents to be treated by a trained provider. The local availability of medical doctors, cost of reaching a healthcare center, household income, type and severity of illness, child's age, and joint parental decision-making about care providers are also important predictors of the selection of trained healthcare providers for children. Thus, climate-related displacement affects the healthcare-seeking behaviors of parents for their children. Policy aimed at improving child health should address the socioeconomic disadvantage and access to healthcare of the displaced, the training of local untrained providers about Primary Health Care service provision, and the numbers of medical doctors in the displacement-prone areas.

During the past decades, land use change in the Lake Victoria basin has significantly increased the sediment fluxes to the lake. These sediments as well as their associated nutrients and pollutants affect the food and water security of millions of people in one of Africa's most densely populated regions. Adequate catchment management strategies, based on a thorough understanding of the factors controlling runoff and sediment discharge are therefore crucial. Nonetheless, studies on the magnitude and dynamics of runoff and sediment discharge are very scarce for the Lake Victoria basin and the African Rift region. We therefore conducted runoff discharge and sediment export measurements in the Upper Rwizi, a catchment in Southwest Uganda, which is representative for the Lake Victoria basin. Land use in this catchment is characterized by grazing area on the high plateaus, banana cropping on the slopes and Cyperus papyrus L. wetlands in the valley bottoms. Due to an increasing population pressure, these papyrus wetlands are currently encroached and transformed into pasture and cropland. Seven subcatchments (358 km2-2120 km2), with different degrees of wetland encroachment, were monitored during the hydrological year June 2009-May 2010. Our results indicate that, due to their strong buffering capacity, papyrus wetlands have a first-order control on runoff and sediment discharge. Subcatchments with intact wetlands have a slower rainfall-runoff response, smaller peak runoff discharges, lower rainfall-runoff ratios and significantly smaller suspended sediment concentrations. This is also reflected in the measured annual area-specific suspended sediment yields (SYs): subcatchments with encroached papyrus swamps have SY values that are about three times larger compared to catchments with intact papyrus vegetation (respectively 106-137 ton km(-2) y(-1) versus 34-37 ton km(-2) y(-1)). We therefore argue that protecting and (where possible) rehabilitating these papyrus wetlands should be a corner stone of catchment management strategies in the Lake Victoria basin.

The objectives of this paper were to analyze the seasonal distributions of climatic and hydrological variables along the Lower São Francisco River, Northeastern Brazil, between the States of Sergipe and Alagoas, and further, to verify their relationships with the erosion of the right margin in Sergipe State. The investigated area comprises the sedimentary portions of the Lower São Francisco River, located at the Cotinguiba-Pindoba Irrigated Perimeter. Historical records of variables such as rainfall, river streamflow velocity, river discharge, wind velocity and the predominant direction were collected from a climatological station as well as rain and streamflow gauges located in the municipality of Propriá. The rainfall that occurs in the region is considered non-erosive, 96.2% of the rain had intensity less than 25.0 mm h-1. The evolution of erosion is explained by the increase in the outflow in February that peaked at 9,894.50 m³ s-1 and led to increases in the flow velocity. The ...

There has been a massive impact of global climate change on the environment that is already evident in various parts of the world. Bangladesh is heavily affected by different climate change issues, and riverbank erosion is one of them. Among others, women are the most vulnerable and suffer the most during the riverbank erosion in Bangladesh. Thus, the key focus of this paper was to understand the impact of riverbank erosion on the lives of women applying a qualitative research method. The objective of the paper was to understand the vulnerabilities and survival strategies of women living in riverbank erosion areas. Findings suggest that the impact of riverbank erosion on the lives of poor women is diverse. It creates a burden for the family members, and in most cases, they fall into a vicious circle of poverty. Despite the increased workload of women due to the unequal distribution of labor in the family, some women also experience a sense of empowerment with their engagement in var...

There has been a massive impact of global climate change on the environment that is already evident in various parts of the world. Bangladesh is heavily affected by different climate change issues, and riverbank erosion is one of them. Among others, women are the most vulnerable and suffer the most during the riverbank erosion in Bangladesh. Thus, the key focus of this paper was to understand the impact of riverbank erosion on the lives of women applying a qualitative research method. The objective of the paper was to understand the vulnerabilities and survival strategies of women living in riverbank erosion areas. Findings suggest that the impact of riverbank erosion on the lives of poor women is diverse. It creates a burden for the family members, and in most cases, they fall into a vicious circle of poverty. Despite the increased workload of women due to the unequal distribution of labor in the family, some women also experience a sense of empowerment with their engagement in various income-generating activities, decision-making process and increased physical mobility.