Coastline Vulnerability Assessment through Landsat and Cubesats in a Coastal Mega City

2020 ◽  
Vol 12 (5) ◽  
pp. 749 ◽  
Author(s):  
Majid Nazeer ◽  
Muhammad Waqas ◽  
Muhammad Imran Shahzad ◽  
Ibrahim Zia ◽  
Weicheng Wu
Keyword(s):  
Spatial Resolution ◽  
Land Reclamation ◽  
Anthropogenic Activities ◽  
Monsoon Season ◽  
Coastal Protection ◽  
Landsat Images ◽  
Intergovernmental Panel ◽  
Eastern Zone ◽  
Stable Conditions ◽  
Western Zone

According to the Intergovernmental Panel on Climate Change (IPCC), global mean sea levels may rise from 0.43 m to 0.84 m by the end of the 21st century. This poses a significant threat to coastal cities around the world. The shoreline of Karachi (a coastal mega city located in Southern Pakistan) is vulnerable mainly due to anthropogenic activities near the coast. Therefore, the present study investigates rates and susceptibility to shoreline change using a 76-year multi-temporal dataset (1942 to 2018) through the Digital Shoreline Analysis System (DSAS). Historical shoreline positions were extracted from the topographic sheets (1:250,000) of 1942 and 1966, the medium spatial resolution (30 m) multi-sensor Landsat images of 1976, 1990, 2002, 2011, and a high spatial resolution (3 m) Planet Scope image from 2018, along the 100 km coast of Karachi. The shoreline was divided into two zones, namely eastern (25 km) and western (29 km) zones, to track changes in development, movement, and dynamics of the shoreline position. The analysis revealed that 95% of transects drawn for the eastern zone underwent accretion (i.e., land reclamation) with a mean rate of 14 m/year indicating that the eastern zone faced rapid shoreline progression, with the highest rates due to the development of coastal areas for urban settlement. Similarly, 74% of transects drawn for the western zone experienced erosion (i.e., land loss) with a mean rate of −1.15 m/year indicating the weathering and erosion of rocky and sandy beaches by marine erosion. Among the 25 km length of the eastern zone, 94% (23.5 km) of the shoreline was found to be highly vulnerable, while the western zone showed much more stable conditions due to anthropogenic inactivity. Seasonal hydrodynamic analysis revealed approximately a 3% increase in the average wave height during the summer monsoon season and a 1% increase for the winter monsoon season during the post-land reclamation era. Coastal protection and management along the Sindh coastal zone should be adopted to defend against natural wave erosion and the government must take measures to stop illegal sea encroachments.

scholarly journals Geochemical and statistical evaluation of groundwater in the Thamirabarani river basin, south India

2021 ◽  
Author(s):  
Gajendran Chellaiah ◽  
Basker ◽  
Hima Pravin ◽  
Suneel Kumar Joshi ◽  
Sneha Gautam
Keyword(s):  
River Basin ◽  
Tamil Nadu ◽  
Statistical Evaluation ◽  
Anthropogenic Activities ◽  
Monsoon Season ◽  
Principal Component ◽  
Chloride Ion ◽  
Temporal Analysis ◽  
Point Sources ◽  
International Standards

Abstract In the present study, an attempt has been made to develop the dictate metrics using a multi-proxy approach, i.e., spatial-temporal analysis, statistical evaluation, and hydrogeochemical analysis for 45 water samples located in the Thamirabarani river basin in Tamil Nadu, India. In order to evaluate the aptness of developed metrics for agriculture and domestic needs, eleven years dataset was analyzed and compared with national and international standards. Monitoring and analysis results revealed that the concentration of calcium and chloride ion was on the higher side in all the selected locations. These higher values may be attributed to the regional point sources such as untreated water disposal and off-peak sources such as agriculture practices. The principal component analysis resulted in 84.2% of the total variance in the post-monsoon season dataset. The major analyzed cations and anions were observed in the following order: Na+> Ca2+> Mg2+> K+ and Cl−> HCO3−> SO42−> NO3−, respectively. Overall, this study revealed that the studied area's groundwater quality was significantly affected by the high salinity in the region, probably due to anthropogenic activities and unprotected river sites.

scholarly journals Coastal morphological changes in the Red River Delta under increasing natural and anthropic stresses

2019 ◽  
Vol 2 (1) ◽  
pp. 51-71 ◽  
Author(s):  
Daidu Fan ◽  
Dac Ve Nguyen ◽  
Jianfeng Su ◽  
Vuong Van Bui ◽  
Dinh Lan Tran
Keyword(s):  
Coastal Erosion ◽  
Land Reclamation ◽  
Morphological Changes ◽  
River Delta ◽  
Sediment Supply ◽  
Red River ◽  
Coastal Protection ◽  
Mangrove Forests ◽  
Red River Delta ◽  
Sediment Redistribution

River deltas are the best place to study intense human–earth interactions and the resultant morphological changes and sedimentary records. The coastal evolution history of the Red River Delta (RRD) is examined by time-series analysis of multiple coastline locations. We find that spatiotemporal variation in seawall locations and vegetation lines are obviously site-specific due to intense human interference, while changes in 0 m isobaths are highly dependent on external stresses. Coastal erosion and deposition patterns are determined firstly by sediment inputs from different distributaries, and secondly by sediment redistribution with tides, waves, and longshore currents. The causes of chronic erosion along the Hai Hau coast include swift distributary channels, negligible sediment supply by the regional longshore current, and continuous sediment export by local wave-generated longshore and offshore currents. The area of intertidal flats decreased significantly due to land reclamation and decelerating coastal accretion. The area of mangrove forests decreased first due to human deforestation, and then increased gradually due to artificial plantation. Poorly designed coastal infrastructures may increase risks of coastal erosion and flooding disasters. More coastal sectors in the RRD may turn into erosion due to continuous decrease in riverine sediment discharges, deserving more attention on proper coastal protection and management.

Databased simulation and reconstruction of the near shore geomorphological structure and sediment composition of the German tidal flats

2020 ◽  
Author(s):  
Julian Sievers ◽  
Peter Milbradt ◽  
Malte Rubel
Keyword(s):  
Spatial Resolution ◽  
Three Dimensional ◽  
Lower Boundary ◽  
Tidal Flats ◽  
Coastal Protection ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Validation Data ◽  
Climate Conditions ◽  
Holocene Sediments

<p>With an area of almost 10,000 km², the project area represents the tidal flats on Germany’s North Sea coast. The tidal flats and their channels as well as morphologically highly active estuarine systems undergo significant erosional and sedimentational processes that prove difficult the assessment of sedimentological composition based on relatively few and temporally far stretched field measurements. The holistic databased simulation of both the internal structure of the soil itself and its sedimentary composition is based on around 21,000 measured surface sediment samples (from 1949 until recent) and yearly consistent digital bathymetric models, starting 1950, spatiotemporally interpolated in a 10 m grid resolution by the Functional Seabed Model. By utilizing the high temporal and spatial resolution of the bathymetric models, it is possible to quantify the seabed depth evolution (sedimentation and erosion) and to solve a differential equation to capture sedimentary evolution, a consistent and continuous three dimensional model of both the surface and the subsurface structures and sedimentary compositions can be generated. To further extend the volumetric extent of the model, around 16,000 sedimentary core samples are used to fill the spatial and consequently the temporal void between the lowest altitudinal range of validity of the aforementioned model segment to the lower boundary of the target model volume. This boundary is set to be the lower limit of the morphologically active or activatable space, which contains the volume of sediment that could be eroded in current climate conditions. The limit, generally speaking, can be expected to somewhat coincide with the base of Holocene sediments, as Pleistocene sediments – especially subglacial tills – generally take higher amounts of bottom shear stress to erode than unindurated Holocene sediments, which usually form tidal flat sediments. The purpose of the generated three dimensional model is to be able to derive sedimentological information in both custom spatial resolution as well as custom sedimentological classification as base and validation data for process based morphodynamic simulation models. With these enhanced models, the quality of the prognosis of morphological developments and stability of coastal areas as a tool for planning processes for coastal protection and maritime economy is expected to be increased.</p>

scholarly journals Effects of livestock on occurrence of the Vulnerable red panda Ailurus fulgens in Rara National Park, Nepal

Oryx ◽  
2014 ◽  
Vol 48 (2) ◽  
pp. 228-231 ◽  
Author(s):  
Hari P. Sharma ◽  
Jerrold L. Belant ◽  
Jon E. Swenson
Keyword(s):  
Habitat Use ◽  
Spatial Resolution ◽  
National Park ◽  
Anthropogenic Activities ◽  
Livestock Grazing ◽  
Faecal Pellets ◽  
Red Panda ◽  
Ailurus Fulgens ◽  
Awareness Raising

AbstractThe Vulnerable red panda Ailurus fulgens is endemic to the Himalayas. Anthropogenic activities, including deforestation, have degraded the species’ habitat but the effects of livestock have not been examined. We assessed the effects of illegal livestock activity on the presence of the red panda in Rara National Park, Nepal. The probability of detecting red panda faecal pellets decreased with livestock occurrence but not with elevation or aspect. The presence of bamboo and proximity to water are important to red pandas but did not influence their habitat use at the spatial resolution evaluated. Livestock grazing in Rara National Park appears to adversely affect the presence of the red panda within its habitat. To reduce illegal livestock grazing we recommend enforcement of existing regulations, that training workshops be held for herders, and awareness-raising and dialogue with residents.

scholarly journals Assessment of island beach erosion due to sea level rise: the case of the Aegean archipelago (Eastern Mediterranean)

2017 ◽  
Vol 17 (3) ◽  
pp. 449-466 ◽  
Author(s):  
Isavela N. Monioudi ◽  
Adonis F. Velegrakis ◽  
Antonis E. Chatzipavlis ◽  
Anastasios Rigos ◽  
Theophanis Karambas ◽  
...  
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Spatial Information ◽  
Eastern Mediterranean ◽  
Sediment Supply ◽  
Coastal Development ◽  
Beach Erosion ◽  
Coastal Protection ◽  
Intergovernmental Panel ◽  
Economic Resource

Abstract. The present contribution constitutes the first comprehensive attempt to (a) record the spatial characteristics of the beaches of the Aegean archipelago (Greece), a critical resource for both the local and national economy, and (b) provide a rapid assessment of the impacts of the long-term and episodic sea level rise (SLR) under different scenarios. Spatial information and other attributes (e.g., presence of coastal protection works and backshore development) of the beaches of the 58 largest islands of the archipelago were obtained on the basis of remote-sensed images available on the web. Ranges of SLR-induced beach retreats under different morphological, sedimentological and hydrodynamic forcing, and SLR scenarios were estimated using suitable ensembles of cross-shore (1-D) morphodynamic models. These ranges, combined with empirically derived estimations of wave run-up induced flooding, were then compared with the recorded maximum beach widths to provide ranges of retreat/erosion and flooding at the archipelago scale. The spatial information shows that the Aegean pocket beaches may be particularly vulnerable to mean sea level rise (MSLR) and episodic SLRs due to (i) their narrow widths (about 59 % of the beaches have maximum widths < 20 m), (ii) their limited terrestrial sediment supply, (iii) the substantial coastal development and (iv) the limited existing coastal protection. Modeling results indeed project severe impacts under mean and episodic SLRs, which by 2100 could be devastating. For example, under MSLR of 0.5 m – representative concentration pathway (RCP) 4.5 of the Fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate change (IPCC) – a storm-induced sea level rise of 0.6 m is projected to result in a complete erosion of between 31 and 88 % of all beaches (29–87 % of beaches are currently fronting coastal infrastructure and assets), at least temporarily. Our results suggest a very considerable risk which will require significant effort, financial resources and policies/regulation in order to protect/maintain the critical economic resource of the Aegean archipelago.

scholarly journals Satellite-based evaluation of temporal change in cultivated land in Southern Punjab (Multan region) through dynamics of vegetation and land surface temperature

2021 ◽  
Vol 13 (1) ◽  
pp. 1561-1577
Author(s):  
Sajjad Hussain ◽  
Muhammad Mubeen ◽  
Ashfaq Ahmad ◽  
Nasir Masood ◽  
Hafiz Mohkum Hammad ◽  
...  
Keyword(s):  
Surface Temperature ◽  
Land Surface Temperature ◽  
Land Surface ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Environmental Changes ◽  
Anthropogenic Activities ◽  
Cropping Pattern ◽  
Landsat Images ◽  
Urban Climatology

Abstract The rapid increase in urbanization has an important effect on cropping pattern and land use/land cover (LULC) through replacing areas of vegetation with commercial and residential coverage, thereby increasing the land surface temperature (LST). The LST information is significant to understand the environmental changes, urban climatology, anthropogenic activities, and ecological interactions, etc. Using remote sensing (RS) data, the present research provides a comprehensive study of LULC and LST changes in water scarce and climate prone Southern Punjab (Multan region), Pakistan, for 30 years (from 1990 to 2020). For this research, Landsat images were processed through supervised classification with maps of the Multan region. The LULC changes showed that sugarcane and rice (decreased by 2.9 and 1.6%, respectively) had less volatility of variation in comparison with both wheat and cotton (decreased by 5.3 and 6.6%, respectively). The analysis of normalized difference vegetation index (NDVI) showed that the vegetation decreased in the region both in minimum value (−0.05 [1990] to −0.15 [2020]) and maximum value (0.6 [1990] to 0.54 [2020]). The results showed that the built-up area was increased 3.5% during 1990–2020, and these were some of the major changes which increased the LST (from 27.6 to 28.5°C) in the study area. The significant regression in our study clearly shows that NDVI and LST are negatively correlated with each other. The results suggested that increasing temperature in growing period had a greatest effect on all types of vegetation. Crop-based classification aids water policy managers and analysts to make a better policy with enhanced information based on the extent of the natural resources. So, the study of dynamics in major crops and surface temperature through satellite RS can play an important role in the rural development and planning for food security in the study area.

scholarly journals Continuous Change Mapping to Understand Wetland Quantity and Quality Evolution and Driving Forces: A Case Study in the Liao River Estuary from 1986 to 2018

2021 ◽  
Vol 13 (23) ◽  
pp. 4900
Author(s):  
Jianwei Peng ◽  
Shuguang Liu ◽  
Weizhi Lu ◽  
Maochou Liu ◽  
Shuailong Feng ◽  
...  
Keyword(s):  
Coastal Wetlands ◽  
Coastal Wetland ◽  
Driving Forces ◽  
Land Reclamation ◽  
River Estuary ◽  
Tidal Flats ◽  
Liaoning Province ◽  
Coastal Zones ◽  
Continuous Change ◽  
Landsat Images

Coastal wetland ecosystems, one of the most important ecosystems in the world, play an important role in regulating climate, sequestering blue carbon, and maintaining sustainable development of coastal zones. Wetland landscapes are notoriously difficult to map with satellite data, particularly in highly complex, dynamic coastal regions. The Liao River Estuary (LRE) wetland in Liaoning Province, China, has attracted major attention due to its status as Asia’s largest coastal wetland, with extensive Phragmites australis (reeds), Suaeda heteroptera (seepweed, red beach), and other natural resources that have been continuously encroached upon by anthropogenic land-use activities. Using the Continuous Change Detection and Classification (CCDC) algorithm and all available Landsat images, we mapped the spatial–temporal changes of LRE coastal wetlands (e.g., seepweed, reed, tidal flats, and shallow marine water) annually from 1986 to 2018 and analyzed the changes and driving forces. Results showed that the total area of coastal wetlands in the LRE shrank by 14.8% during the study period. The tidal flats were the most seriously affected type, with 45.7% of its total area lost. One of the main characteristics of wetland change was the concurrent disappearance and emergence of wetlands in different parts of the LRE, creating drastically different mixtures of wetland quality (e.g., wetland age composition) in addition to area change. The reduction and replacement/translocation of coastal wetlands were mainly caused by human activities related to urbanization, tourism, land reclamation, and expansion of aquaculture ponds. Our efforts in mapping annual changes of wetlands provide direct, specific, and spatially explicit information on rates, patterns, and causes of coastal wetland change, both in coverage and quality, so as to contribute to the effective plans and policies for coastal management, preservation, and restoration of coastal ecosystem services.

scholarly journals Assessment of sources and distribution metals in groundwater of Pondicherry region, India

2020 ◽  
Vol 2 (2) ◽  
pp. 33-53
Author(s):  
Thilagavathi R ◽  
Chidambaram S ◽  
Thivya C ◽  
Banajarani Panda ◽  
Ganesh N
Keyword(s):  
Heavy Metals ◽  
Statistical Analysis ◽  
Anthropogenic Activities ◽  
Monsoon Season ◽  
Heavy Metal Concentration ◽  
Quality Parameters ◽  
Multivariate Statistical ◽  
North East ◽  
Study Results ◽  
South West Monsoon

The proposed study investigates the seasonal variation in the concentration and the source of the heavy metals like Mn, Cu, Pb, Zn and Fe in the groundwater samples of Pondicherry region. The study results reveal that, the heavy metal concentration is high during South West Monsoon season (SWM) compared to that of North East Monsoon season (NEM). The pH was near neutral and metal load representing most of the samples were low during NEM. Statistical analysis shows that the 63.7 % of the total variance is observed during NEM and 68.9% during SWM. Geographic information system (GIS) tool was considered for the study to understand the environmental pollution status of the groundwater systems of the study area and to identify the groundwater quality parameters. The multivariate statistical analysis explains that the source of trace metal in the groundwater is derived from natural origin except copper and lead as these contaminants were derived from anthropogenic activities. Based on the output of WATEQ4F, several species of heavy metals exist, in which the dominant species are Mn, CuCl2, PbCO3, Fe and Zn.

scholarly journals Estimation of COVID-19 Dynamics in the Different States of the United States during the First Months of the Pandemic

2021 ◽  
Vol 5 (1) ◽  
pp. 53
Author(s):  
Ignacio Rojas-Valenzuela ◽  
Olga Valenzuela ◽  
Elvira Delgado-Marquez ◽  
Fernando Rojas
Keyword(s):  
United States ◽  
Time Series ◽  
Dynamic Time Warping ◽  
Hierarchical Cluster ◽  
The United States ◽  
Time Warping ◽  
Precise Knowledge ◽  
Eastern Zone ◽  
Western Zone ◽  
Dynamic Time

Estimation of COVID-19 dynamics and its evolution is a multidisciplinary effort, which requires the unification of heterogeneous disciplines (scientific, mathematics, epidemiological, biological/bio-chemical, virologists and health disciplines to mention the most relevant) to work together towards a better understanding of this pandemic. Time series analysis is of great importance to determine both the similarity in the behavior of COVID-19 in certain countries/states and the establishment of models that can analyze and predict the transmission process of this infectious disease. In this contribution, an analysis of the different states of the United States will be carried out to measure the similarity of COVID-19 time series, using dynamic time warping distance (DTW) as a distance metric. A parametric methodology is proposed to jointly analyze infected and deceased persons. This metric allows comparison of time series that have a different time length, making it very appropriate for studying the United States, since the virus did not spread simultaneously in all the states/provinces. After a measure of the similarity between the time series of the states of United States was determined, a hierarchical cluster was created, which makes it possible to analyze the behavioral relationships of the pandemic between different states and to discover interesting patterns and correlations in the underlying data of COVID-19 in the United States. With the proposed methodology, nine different clusters were obtained, showing a different behavior in the eastern zone and western zone of the United States. Finally, to make a prediction of the evolution of COVID-19 in the states, Logistic, Gompertz and SIR models were computed. With these mathematical models, it is possible to have a more precise knowledge of the evolution and forecast of the pandemic.

scholarly journals An observation-based evaluation and ranking of historical Earth system model simulations in the northwest North Atlantic Ocean

2021 ◽  
Vol 18 (5) ◽  
pp. 1803-1822
Author(s):  
Arnaud Laurent ◽  
Katja Fennel ◽  
Angela Kuhn
Keyword(s):  
Spatial Resolution ◽  
North Atlantic ◽  
Large Scale ◽  
North Atlantic Ocean ◽  
Regional Model ◽  
Biogeochemical Model ◽  
Earth System ◽  
Intergovernmental Panel ◽  
Systems Model ◽  
Current Systems

Abstract. Continental shelf regions in the ocean play an important role in the global cycling of carbon and nutrients, but their responses to global change are understudied. Global Earth system models (ESMs), as essential tools for building understanding of ocean biogeochemistry, are used extensively and routinely for projections of future climate states; however, their relatively coarse spatial resolution is likely not appropriate for accurately representing the complex patterns of circulation and elemental fluxes on the shelves along ocean margins. Here, we compared 29 ESMs used in the Intergovernmental Panel on Climate Change (IPCC)'s Assessment Reports (ARs) 5 and 6 and a regional biogeochemical model for the northwest North Atlantic (NWA) shelf to assess their ability to reproduce surface observations of temperature, salinity, nitrate and chlorophyll. The NWA region is biologically productive, influenced by the large-scale Gulf Stream and Labrador Current systems and particularly sensitive to climatically induced changes in large-scale circulation. Most ESMs compare relatively poorly to observed surface nitrate and chlorophyll and show differences with observed surface temperature and salinity that suggest spatial mismatches in their large-scale current systems. Model-simulated nitrate and chlorophyll compare better with available observations in AR6 than in AR5, but none of the models perform equally well for all four parameters. The ensemble means of all ESMs, and of the five best-performing ESMs, strongly underestimate observed chlorophyll and nitrate. The regional model has a much higher spatial resolution and reproduces the observations significantly better than any of the ESMs. It also simulates reasonably well vertically resolved observations from gliders and bi-monthly ship-based monitoring observations. A ranking of the ESMs indicates that only one ESM has good and consistent performance for all variables. An additional evaluation of the ESMs along the regional model boundaries shows larger variability but is generally consistent with the ranking on the shelf. Overall, 11 ESMs were deemed satisfactory for use in the NWA, either directly or for regional downscaling.

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