Delta Coast Research Articles

Reconstructing Holocene hydroclimate variability and coastal dynamics of the Nile Delta: A diatom perspective

This study analyses diatom assemblages from a Nile Delta core (B-1) to probe Holocene hydroclimate changesand their influence on the ecological habitats of the delta coast, with a further focus on the effects of relative sea-level rise. We found that the freshwater diatom Aulacoseira granulata varied in tandem with hydroclimate pulses in the Nile watershed, driven by the shift of the Intertropical Convergence Zone (ITCZ), therefore serving as a proxy for palaeo-Nile flow. Based on the ecological affinities of diatom taxa, we defined 5 diatom assemblages (I-V). Assemblage I (>10.0-8.5 ka BP) shows high A. granulata abundance (60–80%), implying peak Nile flow during the African Humid Period (AHP), at least 3 times greater than that of the recent past. Assemblage II (8.5-7.5 ka BP) sees decreased A. granulata (20–40%) and emergence of freshwater diatoms with benthic-oligotrophic characteristics (e.g. Epithemia gibba), suggesting reduced Nile flow and a delta estuary where the habitat became shallower with lower nutrient content. Assemblage III (7.5-6.0 ka BP) shows A. granulata resurgence (50–80%), reflecting Nile hydroclimate variability post-AHP due to the migration of the Intertropical Convergence Zone (ITCZ). The high-resolution- diatom spectra of B-1 also revealed major habitat changes, from saline to fluvial-dominated environments, around 6.0 ka BP. Assemblage IV (6.0-3.2 ka BP) indicates a notable Nile flow decline and freshwater community proliferation, coinciding with coastal habitat expansion and delta progradation due to RSL stablisation and basin-wide aridification. Assemblage V (3.2-2.0 ka BP) is marked by drought-tolerant diatoms (Nitzchia amphibia, Hantzschia amphioxys and Cavinula cocconeiformis), indicating intensified aridification.

Divergent dynamics of coastal wetlands in the world’s major river deltas during 1990–2019

Coastal wetlands provide vital dynamic ecosystem services. They have become increasingly important after being linked to several sustainable developmental goals, resulting in a focus on their protection, management, and restoration. Therefore, there is an increasing need to detect and compare coastal wetland spatiotemporal dynamics in deltas at a global scale. In this study, we mapped and characterized coastal wetland spatiotemporal patterns for 1990–2019 in the world’s major river deltas using pixel frequency algorithms and Landsat-4/5 (TM), −7 (ETM + ), −8 (OLI), and Sentinel-2 (MSI) time-series imagery obtained from Google Earth Engine (GEE). Our map had a high overall accuracy (91.84 %) for 2019. Tidal flats were primarily distributed in North America (∼6.87 %) and Asia (∼5.91 %), whereas salt marshes were more commonly found in North America (∼45.39 %) and South America (∼10.61 %). Mangroves are more common in South America (∼11.86 %) and Asia (∼5.83 %), primarily because of the Amazon River Delta and tropical and subtropical regions of Asia, which host several large river deltas. South America had the largest coastal delta wetland area (798,569 km2), followed by Asia (640,251 km2), North America (581,977 km2), Africa (181,977 km2), Europe (140,759 km2), and Oceania (15,915 km2). There was a minor difference in the distribution of wetland vegetation and tidal flats in Asian coastal deltas, and the wetland vegetation area in Asia was greater than that in tidal flats on other continents. We found that the coastal wetland areas increased during 1990–2001, decreased during 2001–2012, and steadily increased during 2012–2019. Our study provides a baseline for monitoring the area, status, and health of the coastal wetlands in these river deltas.

Long-Term Trends in Significant Wave Heights in The Mediterranean as an Indicator of Climate Change

The Mediterranean coastal zones, particularly along the Nile Delta, are increasingly vulnerable to the impacts of climate change. This study examines the historical changes in the significant wave height along the Nile Delta coast over the past 84 years (1940-2023) at a depth of 20 meters. By synthesizing a comprehensive long-term wave data series using ERA5 reanalysis data and the MIKE21-SW model, the study establishes a robust foundation for analysis. To ensure accuracy, the observed wind data were contrasted against ERA5 data, and they were found to be similar to a great extent. Furthermore, the model's accuracy was rigorously validated against the observational data, ensuring the reliability of the results. Three methods were used to obtain the trends for the maximum wave height to ensure robust and reliable trend assessments (i.e., linear regression, Theil-Sen, and ElasticNet). The results were obtained and analyzed, revealing a statistically significant increase in the maximum wave heights during the study period. Particularly, seasonal analysis revealed a positive trend in maximum wave heights during winter and spring (0.15 to 0.67 cm/year respectively). Furthermore, the monthly analysis showed a positive trend in the wave heights for all months except July, August, and September. Specifically, there were notable increases from September to December, ranging from 0.24 to 0.92 cm/year. These findings are consistent with the global trends of increasing wave heights due to climate change. It is essential for developing adaptive coastal management strategies and designing resilient structures. Consequently, the results will assist coastal authorities in mitigating the impacts of climate change on coastal zones.

A holistic approach to salinity intrusion vulnerability assessment using geospatial technologies: An application for mekong delta of vietnam

Saltwater intrusion is a critical natural hazard impacting millions of lives globally, particularly in the Mekong Delta, Vietnam. This study presents a comprehensive approach to assessing saltwater intrusion vulnerability, combining hazard, exposure/sensitivity, and adaptive capacity. We developed a salinity intrusion hazard map using data from 68 monitoring stations and 156 prevention culverts collected on February 23, 2020. Twenty-eight indicators representing exposure, sensitivity, and adaptive capacity were standardized and weighted using the Iyengar-Sudarshan method. Our analysis revealed that 15.74 % of the study area, particularly Mo Cay Bac and Mo Cay Nam districts in Ben Tre province and Dam Doi district in Ca Mau province, exhibits very high vulnerability to saltwater intrusion. These findings provide critical insights for designing effective saltwater intrusion warning systems and implementing targeted disaster risk management strategies in the Mekong Delta. The approach and results are also applicable to similar coastal deltas and regions worldwide, offering a valuable framework for mitigating saltwater intrusion impacts.

Dynamic land cover and ecosystem service changes in global coastal deltas under future climate scenarios

Coastal deltas, housing 4.5% of the global population, face profound shifts due to climate change and intensified human activities. This study utilizes the Patch-generating Land Use Simulation (PLUS) for detailed land cover dynamics and the Integrated Valuation of Ecosystem Services and Trade-Offs (InVEST) models for ecosystem services assessment, focusing on 46 global coastal deltas under future scenarios (SSP126, SSP245, SSP585). Our findings reveal a 145% increase in urban areas from 1995 to 2015, with expected continuations in urban sprawl. Grassland and barren areas are projected to diminish by up to 15% and 5%, respectively, with urban areas potentially expanding by up to 39% across scenarios. Significant decreases in surface water yield under SSP245 and SSP585 could challenge water sustainability. Moreover, a universal decline in carbon storage necessitates enhanced carbon sequestration strategies. Soil retention is anticipated to decline, leading to increased erosion risks, while habitat quality varies, improving in 29 deltas under SSP126 but worsening in 33 under SSP245 and SSP585. These insights underscore the urgency of strategic, adaptive land use planning to bolster ecosystem services, directly supporting the United Nations' Decade of Ocean Science for Sustainable Development and advancing global sustainable delta management.

Evaluation of coastal risks to Sea level rise: Case study of Nile Delta Coast

One of the most effective strategies for coastal management in Egypt is analyzing how the Nile Delta shoreline is adapted for climate change and rising sea levels and identifying the most vulnerable and hotspot sites. Thirteen geological, physical, and socioeconomic factors were identified and assessed to ascertain the level of vulnerability of the Egyptian Delta coast. The rank for each parameter was integrated using two different techniques (Gornitz’s method and Analytical hierarchy process, AHP) to estimate the coastal vulnerability index, CVI. Based on the CVI, similar values gained from both models (72 % correlated), the Nile Delta shoreline is categorized into five vulnerability levels (very high, high, moderate, low, and very low), with about 20 % equal predomination for each. The most vulnerable region is Abo-Khashba Bay, with approximately 60 % of the shoreline bay categorized as very high vulnerability. By contrast, the moderate-very low vulnerability categories predominate the Burullus headland (more than 75 % of the shoreline). The study also reveals that the factors that most influence the vulnerability level in the study area are geomorphology, land elevation, coastal slope, bathymetry, wave exposure, the presence of artificial structures, and land use changes. The findings outlined in this study are significant for future development and could be a basis for future decision-making to prevent further damage to the Nile Delta shoreline.

DISTRIBUTION OF HADROCHEMICAL PARAMETERS, TOXICOLOGY AND HAZARDOUS ELEMENTS BIOACCUMULATION IN PERIWINKLE (TYMPANOTONUS FUSCATUS) FROM THE NIGER DELTA COAST, NIGERIA

The study examined the distribution of physicochemical parameters and toxic metals in the Niger Delta Coast, Nigeria. The shellfish (T. fuscatus), water, sediments, and physicochemical data were collected from three sampling stations over a six-month period. The findings revealed considerable variability in levels of heavy metals and physicochemical features between stations. Station 2 had higher temperature and salinity levels but lower total dissolved solids, pH, biological oxygen demand, and dissolved oxygen. Station 1 had the highest concentrations of Fe, Zn, Cd, Pb, Cu, and As in water and sediment samples, while Station 2 consistently had the lowest concentrations. Station 3 had the highest Fe levels while Station 2 had the lowest Zn values in terms of sediment bioaccumulation. The study found no significant differences (p > 0.05) in all metals in water, T. fuscatus and sediment between stations 1 and 2, except for Cu, which showed slight variation (p < 0.05). In fish, Cu showed slight variation (p < 0.05) between stations 1 and 2, and in sediment, Fe and Cu showed significant differences (p < 0.05) between stations 1. For As bioaccumulation, Station 3 had the greatest concentration, measuring 0.00000123 mg/kg, while both Stations 1 and 2 shared the lowest bioaccumulation at 0.00000058 mg/Kg. Station 3 had the highest Fe bioaccumulation, possibly due to local conditions or iron sources. Higher metal bioaccumulation in these areas may lead to potential environmental and health implications due to their susceptibility to metal pollution. The study suggests that constant assessment and remedial measures are needed to safeguard the aquatic ecosystem in the area.

Exploring Factors Influencing the Internal Displacement Decisions Amidst Natural Disasters in Bangladesh

Bangladesh, a densely populated country in the world’s largest coastal delta, is seriously threatened by the ongoing onslaught of major natural disasters brought on by climate change. The main perpetrators, cyclonic storms and floods cause millions of displaced people each year and increase the vulnerability of communities already facing devastation from the environment and poverty due to these disasters. This study explores the complex patterns of internal displacement brought on by cyclonic storms and floods in Bangladesh from 2008 to 2022. The study identifies the patterns, trends, vulnerable districts, and influencing factors of displacement by analysing data from multiple sources. Every year, an average of 6.14 million people are displaced by floods, a persistent problem. Gaibandha is the district most at risk, having seen 13 floods in the previous 15 years. Throughout the study period, Bhola experienced eight strikes from cyclonic storms that decimated the southern coast. These natural disasters force people to move from environmentally susceptible to safe areas. The disaster’s intensity or frequency and some economic, social, and political factors influence this decision to displace. The study also identifies factors that influence displacement decisions after catastrophic disasters. Additionally, it emphasises the importance of understanding displacement patterns and influencing factors to make informed decisions about displacement in such situations.

Climate Change Impact on Migration Situation in Coastal Delta Belt of Bangladesh: A Qualitative Explorative Study

Climate change is one kind of erratic behaviour and hazards of environmental consequences such as floods, flash floods, drought, heat & cold waves, cyclones, high and low tides, river bank erosion, salinity intrusion, etc. The household survey and qualitative study approaches were performed to explore the changes in vulnerable peoples’ ecological migration perspective in disaster-affected southern part of Bangladesh. People usually move to the nearest town and peri-urban areas to seek jobs due to concurrent cyclones, storm surges, and floods in the coastal areas. Again, heavy rainfall and flash-flood conditions usually create intra-district temporary migration to maintain their daily livelihood smoothly. In the char lands, this migration takes place due to riverbank erosion where family members were forced to relocate to a new residence. It occurs when the income-generating activities of people are disrupted by ecological events. Families leave their homes during the disaster period and return, once the conditions are back to normal. Movement for rural people needs constant land management systems including governance, ownership rights and access and technical support for financing land use and making productive use of land to cope with frequent natural calamities. The government of Bangladesh therefore must consider these challenges and gradually improve its capacity to prepare its technology to renovate the vulnerable local people into a climate resilient one.

STRATEGI PEMBERDAYAAN EKONOMI MELALUI INOVASI TEKNOLOGI AIR BERSIH: STUDI KASUS PENERAPAN REVERSE OSMOSIS DAN PERINTISAN BISNIS

The helplessness of coastal communities in processing salt and brackish water into drinking water is a great irony of modern society, in the midst of technological advances and the industrial era 4.0. The problem in the coastal areas of Sungai Kakap subdistrict, Kubu Raya district, is the lack of availability of clean water and the absence of clean water infrastructure. Peat groundwater in coastal deltas cannot support the use of groundwater sources due to high levels of acid and organic substances. This can trigger problems of poor community sanitation and cause the community's inability to optimize the potential of villages that have abundant natural resources. This activity aims to empower and increase community participation in designing and processing brackish/salt water into drinking water using Reverse Osmosis (RO) technology to meet the need for hygienic ready-to-drink water. Small scale water treatment system design using ultrafiltration (UF) and reverse osmosis (RO) membranes. The raw water used comes from river surface water in coastal areas. The small-scale water treatment design consists of two FRP tubes containing filter media, three filter cartridges, and UF and RO membranes. Two thrust pumps, with a minimum pressure specification of 40 m, are used to provide pressure that exceeds osmosis pressure so that raw water can be filtered through the RO membrane. The results of the activity show that the implementation of the RO system has succeeded in increasing the availability of clean water in Sungai Itik Village, which previously experienced challenges in providing adequate water supply. In addition, the integration of local business startups with RO technology opens up new opportunities for local residents to participate in the local economy and increase family income. Key factors supporting the success of this economic empowerment strategy were identified, including active community involvement in planning and implementation, collaboration between local government and local stakeholders, and adoption of new technologies and skills by local communities. This activity provides an important contribution in understanding the role of clean water technology innovation as a catalyst for local economic transformation in coastal areas. The practical implications of these findings can help decision makers in designing sustainable and effective policies to improve the welfare of coastal communities through sustainable economic empowerment. The use of this technology can help increase the availability of clean water in areas that previously experienced difficulties in this regard.

Shoreline position trends in the Niger Delta: analyzing spatial and temporal changes through Sentinel-1 SAR imagery

Various natural and human-induced processes operating across different temporal scales contribute to the spatial and temporal evolution of shoreline alterations. Deltaic coasts, particularly dynamic geomorphic systems, experience continuous changes at various spatial and temporal dimensions. This investigation underscores the effectiveness of Sentinel-1 Synthetic Aperture Radar (SAR) data in assessing long-term shifts in shoreline positions, focusing on the Niger Delta region. Out of 255 images from 2015 to 2020, 36 were selected based on high tide conditions for each year. This study has pioneered a straightforward and systematic approach rooted in Geographic Information Systems (GIS). This approach offers an accessible pathway for evaluating coastal changes in regions with limited data availability. To better comprehend the heterogeneity of change processes along the shoreline and to pinpoint their causes and mechanisms, we divided the shoreline into distinct sediment cells. This division adheres to a convenient and well-established methodology. This study identifies prevailing erosion trends outweighing accretion, with specific areas showing distinct erosion (cells II, IV, VI, VII, and VIII) and accretion (cells I, III, and V) patterns. Furthermore, coastal areas near river mouths exhibit a higher susceptibility to change. This approach offers a pathway for evaluating coastal changes in data-limited regions and can establish an effective monitoring system benefiting coastal modellers, scientists, and government agencies. It lays the groundwork for comprehensive coastal zone frameworks, facilitating improved planning and management strategies.

Estimation of potential health risks on metals and metalloids contaminants in black goby (Gobius niger) consumption in selected niger delta coast, nigeria

IntroductionThe Niger Delta in Nigeria is subject to anthropogenic influences, impacting the quality of its water bodies, including the Sombrero River. This study aims to investigate the concentrations of metals and metalloids in Gobius niger from the Sombrero River, as these contaminants can pose risks to human health through seafood consumption. Specifically, zinc (Zn), iron (Fe), copper (Cu), lead (Pb), arsenic (As), and cadmium (Cd) were analyzed using atomic absorption spectroscopy (AAS). Materials and MethodsSamples were collected from three different stations along the Sombrero River. The concentrations of Zn, Fe, Cu, Pb, As, and Cd were determined using AAS. Hazard Quotients (HQ), Chronic Daily Intake (CDI), Hazard Index (HI), and Individual Lifetime Cancer Risk (ILCR) values were calculated to assess the potential health risks associated with consuming fish contaminated with these metals and metalloids. ResultsStation 1 had the highest Zn concentration, followed by Fe, Cu, Pb, Cd, and As, with Zn reaching 104.8 ± 1.37 mg kg−1. Station 2 exhibited a similar trend, while Station 3 had Zn as the predominant metal and metalloid. Notably, Pb, As, and Cd levels were consistently low at all stations. While Pb was within permissible limits set by FAO/WHO for contaminants in the fish samples, Zn exceeded regulatory guidelines, suggesting a potential source of contamination. Hazard Quotients (HQ) highlighted a significant risk associated with zinc, especially for children. Chronic Daily Intake values showed metals in fish consumed by adults and children were generally within safe limits, except for Zn, which exceeded Maximum Tolerable Daily Intake (MTDI). Hazard Index values pointed to a substantial long-term health risk, particularly for children due to high zinc levels. However, Individual Lifetime Cancer Risk (ILCR) values were generally below 1, indicating relatively low cancer risks from G. niger consumption for both age groups. ConclusionThis study emphasizes the need for monitoring and managing metals and metalloid pollution in the Niger Delta region to ensure safe seafood consumption and community well-being. While certain metals pose minimal health risks, it highlights the necessity of specific interventions to reduce excessive zinc exposure and safeguard long-term health in the region.

A Model Of Wave Attenuation In Vegetated Environments

Mangrove degradation and rapid coastline erosion have been widely observed at many locations along the Mekong Delta Coast. These locales frequently display narrow mangrove forests, occasionally spanning as few as 100 meters. This phenomenon of the narrower mangrove forests is supposed to be due to the construction of sea dikes in a search to establish room for agricultural purposes and to hinder the salinity intrusion, referred to as "mangrove squeeze". Within the context of monitoring mangrove forest evolution alongside the shoreline's dynamic processes of erosion and accretion, the hypothesis of a "squeeze mangrove forest" was advanced by Phan (2015) and Truong (2017). This conceptual construct underscores the fundamental importance of "mangrove width" as a critical length scale influencing the sustainable growth of a mangrove forest. The physical interpretation of this length scale is intricately tied to the extent of the mixing layer's intrusion into the vegetative domain (Truong et al., 2019). It is important to note that while the mixing dynamics of estuarine mangroves are primarily regulated by lateral flow events induced by large vortex structures moving along the vegetation edge, the characteristics of incoming waves primarily determine the length to which the mixing layer penetrates within coastal mangroves. The latter is the primary focus of this study.

Sustained increase in suspended sediments near global river deltas over the past two decades

River sediments play a critical role in sustaining deltaic wetlands. Therefore, concerns are raised about wetlands’ fate due to the decline of river sediment supply to many deltas. However, the dynamics and drivers of suspended sediment near deltaic coasts are not comprehensively assessed, and its response to river sediment supply changes remains unclear. Here we examine patterns of coastal suspended sediment concentration (SSC) and river sediment plume area (RPA) for 349 deltas worldwide using satellite images from 2000 to 2020. We find a global increase in SSC and RPA, averaging +0.46% and +0.48% yr−1, respectively, with over 59.0% of deltas exhibiting an increase in both SSC and RPA. SSC and RPA increases are prevalent across all continents, except for Asia. The relationship between river sediment supply and coastal SSCs varies between deltas, with as much as 45.2% of the deltas showing opposing trends between river sediments and coastal SSCs. This is likely because of the impacts of tides, waves, salinity, and delta morphology. Our observed increase in SSCs near river delta paints a rare promising picture for wetland resilience against sea-level rise, yet whether this increase will persist remains uncertain.

When water policies derail livelihood aspirations: farmers’ agency in everyday politics in the Vietnamese Mekong Delta

ABSTRACT Development of water infrastructure is conventionally prioritised as a pre-emptive intervention policy to address water challenges. In the Vietnamese Mekong Delta, turning a river into a reservoir is touted as a ‘highly-modernist’ water management approach to secure the year-round supply of freshwater for agricultural production. This paper investigates how contested water-livelihood relations emerged from the building of the Ba Lai sluice scheme in Ben Tre Province, and how these processes demonstrate farmers’ agency in everyday politics in seeking solutions for livelihood sustainability. Drawing on a qualitative case study in Binh Dai District, we argue that, while the scheme successfully fulfils the state’s political intention in securing water supply for freshwater-based crop production in coastal zones, it generates contestation between the local government’s attempts to enforce freshwater policies and farmers’ agency in maintaining productive livelihoods. The findings suggest that power asymmetries are embedded within these water-livelihood relations. We find that seeking just solutions that have co-benefits for water management and livelihood sustainability should go beyond business-as-usual water politics by adequately recognising the agency of farmers in sustainable development. The case study offers lessons for navigating the sustainable future of water development projects in coastal deltas and beyond.

Sources of hydrocarbons and their risk assessment in seawater and sediment samples collected from the Nile Delta coast of the Mediterranean Sea

The aim of this work is to examine the levels, distribution, bases, and hazards of n-alkanes (n-C9 to n-C20) and PAHs in the seawater and sediments around oil production locations in the whole delta region. The variations in the levels of PAHs and n-alkanes in seawater and sediment of the Nile delta coast of the Mediterranean were investigated using GC–MS/MS. The Σn-alkanes residues ranged between 12.05 and 93.51 mg/L (mean: 50.45 ± 17.49 mg/L) and 4.70 to 84.03 µg/g (mean: 31.02 ± 27.995 µg/g) in seawater and sediments, respectively. Total PAHs concentrations ranged between 4.485 and 16.337 μg/L (average: 9.47 ± 3.69 μg/L) and 1.32 to 28.38 ng/g (average 8.61 ± 7.57 ng/g) in seawater and sediment samples, respectively. The CPI (carbon preference index) values fluctuated between 0.62 and 1.72 (seawater) and from 0.234 to 2.175 (sediment), proposing the variation sources of n-alkane in the studied area. PAHs concentrations were lower than the Effective Range Low (ERL) and Effective Range Median (ERM) levels. The Toxic Equivalent Quotient (TEQ) values oscillated between 0.002 and 6.84 ng/L and from 3.72 to 13.48 ng/g for the seawater and sediment samples, respectively. The Ant/(Ant + Phe) ratio in sediment and seawater samples indicated a pyrolytic source while the BaA/(BaA + Chry) ratio indicates petrogenic sources in most of the studied stations.

The coastal dynamics of the Central Ganges–Brahmaputra–Meghna Delta Coast, Bangladesh: implications for coastal development and sustainability

The coastal dynamics of the Central Ganges–Brahmaputra–Meghna Delta Coast, Bangladesh: implications for coastal development and sustainability

Phenotypic plasticity of four invasive species in north-eastern section of the Nile Delta coast, Egypt

Phenotypic plasticity of four invasive species in north-eastern section of the Nile Delta coast, Egypt

Effect analysis of wooden fence width on wave transmission by SWASH model

Wooden fences, a permeable structure, have become a nature-based solution for supporting traditional structures to restore mangrove forests along the Mekong deltaic coasts. Even though prior studies have explored a number of hydraulic functions of these fences, an in-depth investigation into the influence of fence width on wave dissipation and damping is needed to consider. Therefore, this paper employs a numerical approach to thoroughly examine the impact of fence width on wave damping. The findings illustrate the substantial role of fence width in governing the dissipation of incoming waves. The correlation between the transmission coefficient and the fence width is established. This relationship also concludes that the larger the fence thicknesses, the lower the transmission coefficients. Notably, the study also identifies that the transmission coefficient experiences a slight decline beyond a certain width threshold.

Land subsidence studies in the Godavari Delta regions of the East coast of India using ALOS and Sentinel 1 data

Subsidence in coastal deltas is a challenging issue globally, influenced by both climate and anthropogenic pressures. Owing to its rich economic value, the Godavari Delta on the east coast of India attracts the human population and is therefore a hub of developmental activities. We quantified the line of sight (LOS) rate of land deformation in the Godavari Delta, India, for two different periods using the time series interferometric analysis of Advanced Land Observing Satellite Phase Arrayed L-band Synthetic Aperture Radar (ALOS PALSAR) (2007–2011) and C-band Sentinel-1A (2017–2020) datasets. This approach was based on the Small Baseline Subset (SBAS) algorithm, which constructed 76 (ALOS) and 333 (Sentinel-1A) pairs of interferograms. The results indicated that the majority of deltas had varying LOS deformation rates in both periods. The southern and northern coastline of the deltas showed subsidence (-10 to -20 mm/yr) and uplift (5 mm to 7 mm/yr), respectively, from 2007 to 2011. The uplift (11 mm/yr) during 2017–2020 was attributed to coastal erosion and accretion during the study period. Statistical analyses showed that the majority of the coastline experienced erosion from 2006 to 2011, ranging from 0 ‐30 m/yr. Conversely, during 2017–2019, accretion ranging from 0-30 m/yr was dominant. The Kakinada spit has recently experienced an uplift of 8 mm/yr. Many factors contributing to deformation, such as groundwater fluctuations, rainfall, land use and land cover (LULC) changes, and water quality, were explored. Groundwater level variations were strongly correlated with the rate of deformation. A direct relationship was also observed between water recharge through rainfall and the ground deformation rate. The subsidence rate was estimated as 0 to ‐8 mm/yr from 2007-2011 and -10 to -20 mm/yr for 2017–2020 in the Godavari Delta. Increased urban areas and land conversion from the LULC analysis were the causative factors of subsidence in this region. Thus, the Godavari Delta will become highly vulnerable, as the region has shown various LOS deformation rates. Studies on land subsidence are highly relevant for effective coastal management planning and management.