INFLUENCES OF HURRICANES, FLOODS, AND ORGANIC PRODUCTION ON RIVER DELTA EVOLUTION

2016 ◽  
Author(s):  
Crawford White ◽  
◽  
Samuel J. Bentley ◽  
Samuel J. Bentley ◽  
Kehui Xu ◽  
...  
Keyword(s):  
Organic Production ◽  
River Delta ◽  
Delta Evolution

Evolution of the Ofanto River delta from the ‘Little Ice Age’ to modern times: Implications of large-scale synoptic patterns

The Holocene ◽  
2018 ◽  
Vol 28 (12) ◽  
pp. 1948-1967 ◽  
Author(s):  
Vincenzo De Santis ◽  
Massimo Caldara ◽  
Antonella Marsico ◽  
Domenico Capolongo ◽  
Luigi Pennetta
Keyword(s):  
Large Scale ◽  
Low Pressure ◽  
River Delta ◽  
Ice Age ◽  
Aerial Photographs ◽  
Anthropogenic Factors ◽  
Synoptic Patterns ◽  
Delta Evolution ◽  
Circulation Mode

We reconstruct the evolution of the Ofanto River delta from the 17th century to the present using historical maps (1600–1850), official IGM topographic maps (1850–1980) and recent aerial photographs (2015), and we compare long-term morphological changes with the evolution of the delta of the Volturno River during the same time period. The aim of this study is to define the role of climatic (flood frequency, synoptic pressure patterns) and anthropogenic factors (deforestation, anthropogenic sediment subtraction of river sediment) in the evolution of the Ofanto delta. We analysed the importance of each factor on the evolution of the delta and compared them with the simultaneous behaviour of the Volturno delta to highlight the role of large-scale synoptic pressure patterns. We found that the main driver of different delta evolution phases is weather-climatic condition, while anthropogenic factors interacted with the delta evolution in different ways but did not control the first-order evolution. In particular, analysing the data on recent floods, we found that the most favourable situations for both rivers are omega-blocking, deep low-pressure trough and strong meridional circulation (mode Ω) which create Mediterranean low-pressure systems. Instead, a zonal circulation (mode W) can only cause floods on Volturno. Because the evolution of a delta is driven by the frequency of floods, and because we found that the frequency of floods is guided by synoptic patterns, a relationship can be established between delta evolution and synoptic patterns in the past. Consequently, past phases of the contemporary progradation of the Ofanto and Volturno deltas suggest the increasing frequency of mode Ω, while phases of simultaneous progradation of the Volturno delta and stability and/or retreat of the Ofanto delta are indicative of the increasing frequency of mode W. The only exception occurred during the last evolutionary phase (60 years), when anthropogenic sediment subtraction was prevalent.

Holocene Delta Evolution and Depositional Models of the Mekong River Delta, Southern Vietnam

2005 ◽  
pp. 453-466 ◽  
Author(s):  
THI KIM OANH TA ◽  
VAN LAP NGUYEN ◽  
MASAAKI TATEISHI ◽  
IWAO KOBAYASHI ◽  
YOSHIKI SAITO
Keyword(s):  
River Delta ◽  
Mekong River ◽  
Mekong River Delta ◽  
Delta Evolution ◽  
Southern Vietnam ◽  
Depositional Models

Piecing together the Ganges-Brahmaputra-Meghna River delta: Use of sediment provenance to reconstruct the history and interaction of multiple fluvial systems during Holocene delta evolution

2014 ◽  
Vol 126 (11-12) ◽  
pp. 1495-1510 ◽  
Author(s):  
Steven L. Goodbred ◽  
Penny M. Paolo ◽  
Mohammad Shahid Ullah ◽  
Russell D. Pate ◽  
Sirajur R. Khan ◽  
...  
Keyword(s):  
River Delta ◽  
Sediment Provenance ◽  
Fluvial Systems ◽  
Delta Evolution ◽  
The Ganges ◽  
Meghna River Delta

scholarly journals Mathematical Reconstruction of Eroded Beach Ridges at the Ombrone River Delta

Water ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2281
Author(s):  
Irene Mammì ◽  
Lorenzo Rossi ◽  
Enzo Pranzini
Keyword(s):  
Image Enhancement ◽  
Human Activity ◽  
Coastal Erosion ◽  
Numerical Models ◽  
Remotely Sensed ◽  
River Delta ◽  
Lidar Data ◽  
Beach Ridges ◽  
Delta Evolution ◽  
Remotely Sensed Images

Several remotely sensed images, acquired by different sensors on satellite, airplane, and drone, were used to trace the beach ridges pattern present on the delta of the River Ombrone. A more detailed map of these morphologies, than those present in the literature, was obtained, especially at the delta apex, where beach ridges elevation in minor. Beach ridges crests, highlighted through image enhancement using ENVI 4.5 and a DTM based on LiDAR data, were then processed with ArcGIS 9.3 software. Starting from this map, a method to reconstruct beach ridges segments deleted by the transformations of the territory is proposed in this paper. The best crest-lines fitting functions were calculated through interpolation of their points with Curve Expert software, and further extrapolated to reconstruct the ridges morphology where human activity, riverbed migration, or coastal erosion eliminated them. This allowed to reconstruct the ridges pattern also offshore the present delta apex, where the shoreline retreated approximately 900 m in the last 150 years. Results can be further used to implement conceptual and numerical models of delta evolution.

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