scholarly journals COASTAL RESILIENCE IN THE INDUS DELTA; UPSCALING NATURE-BASED SOLUTIONS

2020 ◽  
pp. 39
Author(s):  
Emma J. Rendle ◽  
Nathan A. Rive ◽  
Asad A. Zafar
Keyword(s):  
Flood Risk ◽  
Agricultural Land ◽  
Water Levels ◽  
Land Loss ◽  
Management Interventions ◽  
Coastal Belt ◽  
Sindh Province ◽  
Indus Delta ◽  
Coastal Resilience ◽  
Sediment Connectivity

Sindh province, Pakistan is home to the seventh largest delta, at the mouth of the River Indus and holder RAMSAR designation. A large arid mangrove forest system once occupied the coastal belt. Systematic removal over the past 50 years has exposed the delta to energy higher during cyclones and climate related threats, most notably rising water levels and combined flood risk from extreme events. The loss of mangrove has resulted in agricultural land loss, saline intrusion, and population migration. The Sindh Coastal Resilience Project introduces a National Adaptation Plan alongside investment in key flood risk management interventions; enhancing the mangrove buffer to provide stability, improving water and sediment connectivity, and introducing embankments and flood schemes at key nodal points through the Indus Delta.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/MzBJzHOw4yw

scholarly journals A Case Study of the Effects of Management Interventions on the Phosphorus Dynamics at a Coastal, Eutrophic, Caribbean lagoon (Laguna Cartagena, Puerto Rico)

Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 449
Author(s):  
Yashira Marie Sánchez Colón ◽  
Fred Charles Schaffner
Keyword(s):  
Puerto Rico ◽  
Water Column ◽  
Water Levels ◽  
Wildlife Habitat ◽  
Freshwater Wetland ◽  
Water Level Fluctuations ◽  
Phosphorus Loading ◽  
Estuarine Wetlands ◽  
Management Interventions ◽  
Management Recommendations

Laguna Cartagena is a coastal, eutrophic, shallow lake and freshwater wetland in southwestern Puerto Rico, managed by the US Fish and Wildlife Service. This ecosystem has been impacted by phosphorus loading from adjacent agricultural areas since the 1950s, causing eutrophication and deteriorating wildlife habitats. Herein, we describe phosphorus input and export during September 2010–September 2011 (Phase One) and October 2013–November 2014 (Phase Two). These two phases bracket a period of intensified management interventions including excavation and removal of sediment and vegetation, draining, and burning during the summers of 2012 and 2013. Results indicate that Laguna Cartagena retains a phosphorus (sink) in its sediments, and exhibits nutrient-releasing events (source, mainly total phosphorus) to the lagoon water column, which are associated with rainfall and rising water levels. External factors including water level fluctuations and rainfall influenced phosphorus export during Phase One, but after management interventions (Phase Two), internal processes influenced sink/source dynamics, releasing elevated phosphorus concentrations to the water column. When exposed sediments were re-flooded, phosphorus concentrations to the water column increased, releasing elevated P concentrations downstream to an estuarine wetlands area and the Caribbean Sea. Herein we offer management recommendations to optimize wildlife habitat without elevating phosphorus concentrations.

scholarly journals Assessing the hydrological impacts of agricultural changes upstream of the Tunisian World Heritage sea-connected Ichkeul Lake

2015 ◽  
Vol 365 ◽  
pp. 61-65 ◽  
Author(s):  
J. Aouissi ◽  
Z. L. Chabaane ◽  
S. Benabdallah ◽  
C. Cudennec
Keyword(s):  
Agricultural Land ◽  
World Heritage ◽  
Water Levels ◽  
World Heritage Site ◽  
Landsat Images ◽  
Heritage Site ◽  
Unesco World Heritage Site ◽  
Ichkeul Lake ◽  
The Impact

Abstract. The impact of changes in agricultural land use and practices as a controlling driver of hydrologic response and as a source of diffuse pollution, are studied in the Joumine River basin, discharging into the Ichkeul Lake, northern Tunisia, a UNESCO World Heritage site since 1979. The lake is characterized by a very specific hydrological functioning based on a seasonal alternation of water levels and salinity through its link to the Mediterranean Sea. Three Landsat images, in situ surveys and SWAT modelling were used to simulate and assess streamflows and nitrate loads under retrospective land uses.

scholarly journals GIS-Based Climate Change Induced Flood Risk Mapping in Uhunmwonde Local Government Area, Edo State, Nigeria

2020 ◽  
pp. 8-23
Author(s):  
Obot Akpan Ibanga ◽  
Osaretin Friday Idehen
Keyword(s):  
Climate Change ◽  
Local Government ◽  
Flood Risk ◽  
Vegetation Index ◽  
Agricultural Land ◽  
Local Government Area ◽  
Risk Mapping ◽  
Risk Zone ◽  
Edo State ◽  
Risk Zones

Introduction: Flood is one of the climate change induced hazards occurring in most parts of the world. It exposes humanity and many socio-ecological systems to various levels of risks. In Nigeria, extreme rainfall events and poor drainage system have caused inundation of several settlements to flooding. To contain the disaster, risk mapping were among the measures recommended. Aims: The aim of this paper is to highlight flood risk zones (FRZ) in Uhunmwonde Local Government Area (LGA), Edo State, Nigeria. Methodology: Flood risk (FR) was mapped using hazards and vulnerability and implemented using geographic information system (GIS)-based multi-criteria analysis analytic hierarchy process (MCA-AHP) framework by incorporating seven environmental and two socio-economic factors. Elevation, flow accumulation, soil water index of wettest quarter, normalized difference vegetation index, rainfall of wettest quarter, runoff of wettest quarter and distance from rivers constituted the hazard component while population density and area of agricultural land use was the vulnerability layer. The climate change induced flood risk was validated using the responses of 150 residents in high, moderate and low flood risk zones. Results: The resulting flood risk map indicated that about 40.4% of Uhunmwonde LGA fell within high flood risk zone, 35.3% was categorized under moderate flood risk zone whereas low flood risk zone extended up to about 24.3% of the LGA. The high number of respondents who reported occurrence of flooding with frequency being very often and the fact that flooding was a very serious environmental threat during on-the-spot field assessment validated the generated climate change induced flood risk. Conclusion: The utilitarian capabilities of GIS-based MCA-AHP framework in integrating remotely-sensed biophysical and climate change related flood inducing indicators with socio-economic vulnerabilities to arrive at composite flood risk was demonstrated.

scholarly journals An advanced method for flood risk analysis in river deltas, applied to societal flood fatality risks in the Netherlands

2014 ◽  
Vol 2 (2) ◽  
pp. 1637-1670 ◽  
Author(s):  
K. M. de Bruijn ◽  
F. L. M. Diermanse ◽  
J. V. L. Beckers
Keyword(s):  
Risk Analysis ◽  
Flood Risk ◽  
Hydrodynamic Interaction ◽  
Storm Surges ◽  
Water Levels ◽  
Analysis Framework ◽  
Flood Risks ◽  
River Deltas ◽  
River Flood ◽  
Flood Risk Analysis

Abstract. This paper discusses the new method developed to analyse flood risks in river deltas. Risk analysis of river deltas is complex, because both storm surges and river discharges may cause flooding and since the effect of upstream breaches on downstream water levels and flood risks must be taken into account. A Monte Carlo based flood risk analysis framework for policy making was developed, which considers both storm surges and river flood waves and includes hydrodynamic interaction effects on flood risks. It was applied to analyse societal flood fatality risks (the probability of events with more than N fatalities) in the Rhine–Meuse delta.

scholarly journals Modelisation Hydraulique Mono Dimensionnel Par HEC RAS, Application Sur L’oued Aggay (Ville De Sefrou)

2018 ◽  
Vol 14 (18) ◽  
pp. 110 ◽  
Author(s):  
Meriam Lahsaini ◽  
Hassan Tabyaoui
Keyword(s):  
Urban Planning ◽  
Cultural Heritage ◽  
Statistical Methods ◽  
Flood Risk ◽  
Water Levels ◽  
Hydrological Study ◽  
Geographical Position ◽  
The Subject ◽  
Flooded Area ◽  
The City

The city of Sefrou, because of its geographical position, its cultural heritage and urban planning, than economically, is classified as one of the sites with a vulnerability particular to floods. Oued Aggay, the subject of this study, constitutes a danger potential because of the violence of its floods. In this perspective that comes this study that part of the creation and management of a spatial database on flood risk in the Sebou basin. It aims to spatialize the extent of the floods of Oued Aggay and propose solutions to protection the city of Sefrou against floods. The chosen approach goes through a hydrological study, the choice of profiles and the construction of onedimensional model from HEC RAS hydrology software. This study allowed us to simulate floods by statistical methods, identify flood zones and determine the different water levels in the flooded area for the Oued Aggay watershed.

scholarly journals DEVELOPMENT OF A FLOOD RISK ASSESSMENT MODEL FOR A BRAIDED RIVER SYSTEM

2017 ◽  
pp. 25
Author(s):  
Mustafa Kemal Cambazoglu ◽  
Cheryl Ann Blain
Keyword(s):  
Risk Management ◽  
Flood Risk ◽  
Channel Model ◽  
River System ◽  
Flood Risk Management ◽  
High Flow ◽  
Water Levels ◽  
Pearl River ◽  
Braided River ◽  
River Channels

The aim of this study is to construct a modeling system that will assist flood risk management strategies in a coastal plain braided river system. The model configuration consists of a hydrodynamic model (ADCIRC) of the river basin that receives tidal forcing at the open boundary and river discharge forcing at upstream flux boundary. An unstructured mesh model resolving the Pearl River channels at higher resolution from the coastline to approximately 75km inland to upstream reaches of the river has been constructed. The modeling system produces water levels and currents throughout the Lower Pearl River Basin. Initial sensitivity analysis efforts on the channel model include consideration of low-flow, average-flow, and high-flow scenarios. Model results were found to be slightly sensitive to slope of river channels and bottom friction to control stability in predictions. The model results were shown to be highly sensitive to the bathymetry of the model that controls the discharge capacity of the narrow river channels and the channel model resulted in elevated currents and water levels under high flow conditions. A channel discharge capacity analysis was conducted and the results showed the need to construct a floodplain mesh around the channel model with more realistic bathymetry and topography so that the flooding scenarios could be modeled with wetting and drying capability of ADCIRC. An initial attempt to develop such a floodplain mesh has been made with preliminary results and more comprehensive validation of the developed floodplain modeling system will extend to reproducing events associated with the historical Hurricane Isaac that impacted the region in 2012. This modeling system will provide an important tool to decision makers that could be used in future flood risk management and mitigation efforts.

scholarly journals Agricultural Land Abandonment and Farmers’ Perceptions of Land Use Change in the Indus Plains of Pakistan: A Case Study of Sindh Province

2019 ◽  
Vol 11 (17) ◽  
pp. 4663
Author(s):  
Habibullah Rajpar ◽  
Anlu Zhang ◽  
Amar Razzaq ◽  
Khalid Mehmood ◽  
Maula Bux Pirzado ◽  
...  
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Survey Data ◽  
Agricultural Land ◽  
Environmental Changes ◽  
Secondary Data ◽  
Land Abandonment ◽  
Agricultural Lands ◽  
Sindh Province ◽  
The Government

Agriculture is the mainstay of Pakistan’s economy. However, it has been noticed that farmers are increasingly giving up agriculture in favor of non-agricultural activities. This study was conducted in the Khairpur district of Sindh province, which is part of the Indus Plains in Pakistan. The main purpose of the study was to investigate the current and future land use change (LUC) trends and to study farmers’ perceptions of the causes and consequences of LUC and agricultural land abandonment (ALA) in the study area. The study used field survey data and secondary data obtained from the government sources. The results show that agricultural land in the region has decreased by about 9% in the past two decades. Survey data analysis confirms this because more than 80% of farmers believe that agricultural land in the area has declined over time. In addition, farmers believe that socioeconomic and environmental changes are the main reasons for LUC and ALA. We used a logistic regression model to determine the factors that influence farmers’ decisions to sell agricultural land for other uses. The results show that the age, income, land ownership, farm inheritance by successors, social networks and lack of basic facilities in the study area are the main determinants of farmers’ decisions to sell agricultural lands. In particular, farmers’ integration into the social network and their belief that the farm will be inherited by heirs reduces the possibility of selling land. As for the consequences of LUC and ALA, the results indicate that farmland prices, weeds infestation, urban diffusion, and pressure on existing infrastructure have increased in the study area. In addition, the results show that the prospects of farming in the area remain grim as most farmers indicated that they were willing to abandon agricultural lands in favor of other revenue generation activities. The study suggests that policymakers should pay close attention to controlling rapid LUC and ALA to keep lands green.

scholarly journals Drought Sensitivity and Trends of Riparian Vegetation Vigor in Nevada, USA (1985–2018)

2020 ◽  
Vol 12 (9) ◽  
pp. 1362 ◽  
Author(s):  
Christine M. Albano ◽  
Kenneth C. McGwire ◽  
Mark B. Hausner ◽  
Daniel J. McEvoy ◽  
Charles G. Morton ◽  
...  
Keyword(s):  
Riparian Vegetation ◽  
Vegetation Index ◽  
Agricultural Land ◽  
Statistical Significance ◽  
Climatic Variability ◽  
Water Levels ◽  
Private Land ◽  
Riparian Areas ◽  
Vegetative Cover ◽  
Vegetation Responses

Dryland riparian areas are under increasing stress due to expanding human water demands and a warming climate. Quantifying responses of dryland riparian vegetation to these pressures is complicated by high climatic variability, which can create strong, transient changes in vegetation vigor that could mask other disturbance events. In this study, we utilize a 34-year archive of Landsat satellite data to (1) quantify the strength and timescales of vegetation responses to interannual variability in drought status and (2) isolate and remove this influence to assess resultant trends in vegetation vigor for riparian areas across the state of Nevada, the driest state in the USA. Correlations between annual late-summer Normalized Difference Vegetation Index (NDVI) and the Standardized Precipitation–Evapotranspiration Index (SPEI) were calculated across a range of time periods (varying timing and durations) for all riparian pixels within each of the 45 ecoregions, and the variability of these values across the study area is shown. We then applied a novel drought adjustment method that used the strongest SPEI–NDVI timescale relationships for each ecoregion to remove the influence of interannual drought status. Our key result is a 30 m resolution map of drought-adjusted riparian NDVI trends (1985–2018). We highlight and describe locations where impacts of invasive species biocontrol, mine water management, agriculture, changing water levels, and fire are readily visualized with our results. We found more negatively trending riparian areas in association with wide valley bottoms, low-intensity agricultural land uses, and private land ownerships and more positive trends in association with narrow drainages, public lands, and surrounding perennial water bodies (an indication of declining water levels allowing increased vegetative cover). The drought-adjusted NDVI improved the statistical significance of trend estimates, thereby improving the ability to detect such changes. Results from this study provide insight into the strength and timescales of riparian vegetation responses to drought and can provide important information for managing riparian areas within the study area. The novel approach to drought adjustment is readily transferrable to other regions.

scholarly journals Feedback Mechanism in Bifurcating River Systems: the Effect on Water-Level Sensitivity

Water ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1915
Author(s):  
Matthijs R.A. Gensen ◽  
Jord J. Warmink ◽  
Fredrik Huthoff ◽  
Suzanne J.M.H. Hulscher
Keyword(s):  
Water Level ◽  
Flood Risk ◽  
River System ◽  
Feedback Mechanism ◽  
Water Levels ◽  
River Systems ◽  
Water Level Variations ◽  
System Water ◽  
Discharge Distribution ◽  
Single Branch

Accurate and reliable estimates of water levels are essential to assess flood risk in river systems. In current practice, uncertainties involved and the sensitivity of water levels to these uncertainties are studied in single-branch rivers, while many rivers in deltas consist of multiple distributaries. In a bifurcating river, a feedback mechanism exists between the downstream water levels and the discharge distribution at the bifurcation. This paper aims to quantify the sensitivity of water levels to main channel roughness in a bifurcating river system. Water levels are modelled for various roughness scenarios under a wide range of discharge conditions using a one-dimensional hydraulic model. The results show that the feedback mechanism reduces the sensitivity of water levels to local changes of roughness in comparison to the single-branch river. However, in the smaller branches of the system, water-level variations induced by the changes in discharge distribution can exceed the water-level variations of the single-branch river. Therefore, water levels throughout the entire system are dominated by the conditions in the largest branch. As the feedback mechanism is important, the river system should be considered as one interconnected system in river maintenance of rivers, flood-risk analyses, and future planning of river engineering works.

scholarly journals Flood forecasting using a coupled hydrological and hydraulic model (based on FVM) and highresolution meteorological model

2018 ◽  
Vol 40 ◽  
pp. 06028 ◽  
Author(s):  
Marcos Sanz-Ramos ◽  
Arnau Amengual ◽  
Ernest Bladé ◽  
Romu Romero ◽  
Hélène Roux
Keyword(s):  
Flood Risk ◽  
Overland Flow ◽  
Extreme Rainfall ◽  
Flood Forecasting ◽  
Water Levels ◽  
Flood Risk Assessment ◽  
Flood Events ◽  
Risk Models ◽  
Meteorological Model ◽  
Risk Assessment And Management

A forecasting systems based on the coupling of meteorological, hydrologic, hydraulic and risk models is used to minimize the risks associated to water scarcity and flooding. The fulfilment of such complex forecasting chains can allow obtaining information of the most plausible scenarios of water and risk management up to 96 hours ahead. In the present work, flood forecasting was carried out for different events in the upper La Muga basin (including the reservoir), within the European project “Flood Risk Assessment and Management in the Pyrenees” (http://pgriepm. eu/). The main purpose of the project was to develop a method to optimize the management of flood scenarios in order to minimize the flood risk while maximizing the water resources. The good fit of all the models, obtaining the forecasting rainfall and converting the overland flow in water levels in the reservoir, can give tools and important information to the authorities or dam managers for suitable management during the extreme rainfall and flood events.

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