Land-water Interface Research Articles

Modeling of input signals reflected from coastal zones and observed by small-sized radar systems from UAVs

When developing modern unmanned aerial vehicle-based onboard small-sized radar systems, which are used for monitoring of coastal zones for their operational and environmental purposes, adequate mathematical models are needed of reflections from the corresponding resolution elements of the underlying surfaces, located on the water–land interface. We consider the development of some mathematical models for such applications. We analyze two modern approaches used in developing mathematical models for input signals reflected both separately from the terrestrial and marine surfaces and simultaneously from two aforementioned surfaces at once. A statistical approach and two families of distributions are chosen for modeling the signals, which enable synthesis of efficient algorithms for modeling the fluxes of random variables. The input signals of sea surface reflections are approximated by the log-normal law, while the reflections from the land surface are approximated by the Weibull distribution. For edge-coastal modeling, it is proposed to use the law of distribution of the vector sum of the flux of random variables comprising the input signals reflected from elementary land and sea areas that simultaneously fall within the corresponding resolution element. A highlight of the models developed is the consideration of both the probability distribution laws of the reflected signals and their correlation-spectral characteristics between resolution elements, as well as the anisotropy of reflections when monitoring surfaces from several angles. The presented mathematical models are consistent with experimental data sets of reflections, obtained from coastal zones. The development of coastal reflection models and corresponding modeling algorithms reduces the required number of actual field tests and saves time for implementation of monitoring systems, and hence, limits the overhead of this implementation.

Planning and Professional Assistance as Factors Influencing Private Forest Landowner Best Management Practice Implementation

Abstract Virtually all states have developed best management practices (BMPs) to mitigate potential adverse effects associated with timber harvesting. This study examined how BMP implementation on Minnesota’s family forest lands varied according to whether the land had a forest management plan, the timber sale was administered by a forester, or a written timber harvesting contract was used. Analysis of field monitoring data from 174 commercial timber harvesting sites on family forest lands found that BMP implementation is only modestly influenced by a forest management plan, supervising forester, or timber harvesting contract. Supervision of a forester had the greatest influence, with six guidelines implemented differently. In contrast, differences were found for just two BMPs with a forest management plan and only one with a written timber harvesting contract. When timber sales were administered by a forester, forest management guidelines generally related to management of the land-water interface were implemented to a higher standard, with significant increases observed for avoidance of infrastructure in filter strips, use of water diversion and erosion control structures, avoiding unnecessary wetland and waterbody crossings, and slash management. Higher timber utilization efficiency (within leave tree guidelines) was also found when a professional forester supervised the timber sale. Study Implications: We examine how BMP implementation on family forest lands varies with three types of supervisory and planning assistance: a forest management plan for the property, sale administration by a professional forester, and a written timber harvesting contract. Field monitoring data from 174 commercial timber harvests on family forest lands indicate that BMP implementation is only modestly influenced by any single form of assistance. Supervision by a forester had the greatest influence, increasing use of four guidelines related to management of the land-water interface. Results may help to inform best practices for landowner assistance and planning.

Collateral implications of carbon and metal pollution on carbon dioxide emission at land-water interface of the Ganga River.

Atmospheric CO2 source and sink is among the most debated issues that have puzzled climate change geochemist for decades. Here, we tested whether heavy metal pollutants in river sediments favor preservation of organic matter through shielding microbial degradation. We measured CO2 emission and extracellular enzyme activities at land-water interface (LWI) of 7 sites along a 285 km main stem of the Ganga River and 60 locations up- and downstream of two contrasting point sources discharging urban (Assi drain; Asdr) and industrial (Ramnagar drain; Rmdr) wastewaters to the river. We found the lowest CO2 flux at Rmdr mouth characterized by the highest concentrations of Cu, Cr, Zn, Pb, Ni, and Cd. The fluxes were relatively higher at locations up- and downstream Rmdr. Substrate induced respiration (SIR), protease, FDAase, and β-D-glucosidase all showed a similar trend, but phenol oxidase and alkaline phosphatase showed opposite trend at the main river stem and Asdr. Sites rich in terrestrially derived organic matter have high phenol oxidase activity with low CO2 emission. The CO2 emission in the main river stem showed curvilinear relationships with total heavy metals (∑THM; R2 = 0.68; p < 0.001) and TOC (R2 = 0.65; p < 0.001). The dynamic fit model of main stem data showed that the ∑THM above 337.4 µg g-1 were able to significantly decrease the activities of protease, FDAase, and β-D-glucosidase. The study has implications for understanding C-cycling in human-impacted river sediments where metal pollution shields microbial degradation consequently carbon and nutrient release and merits attention towards river management decisions.

Enhanced Sediment Denitrification for Nitrogen Removal by Manipulating Water Level in the Lakeshore Zone

Denitrification of sediments is an important way to remove reactive nitrogen in lakeshore zones. In this work, we analyzed sediment denitrification patterns across the shore zone of Lake Taihu and explored their underlying mechanisms using flooding simulation experiments. The results showed that denitrification mainly occurred in the upper sediment layer (0–10 cm) and the denitrification rate was highest at the land–water interface (6.2 mg N/m2h), where there was a frequent rise and fall in the water level. Denitrification was weaker in the lakebed sediments (4.6 mg N/m2h), which were inundated long-term, and in the sediments of the near-shore zone (2.3 mg N/m2h), which were dried out for extended periods. Flooding simulation experiments further indicated a strong positive relationship between sediment denitrification rate and flooding frequency. When the flooding occurred once every 3, 6, 9, 12, or 15 days, the denitrification rate reached 7.6, 5.7, 2.8, 0.9, and 0.6 mg N/m2h, respectively. Frequent flooding caused alternating anoxic and aerobic conditions in sediments, accelerating nitrogen substrate supply and promoting the growth and activity of denitrifying bacteria. Based on these findings, we propose a possible strategy for enhancing sediment denitrification by manipulating the water level, which can help guide nitrogen removal in lakeshore zones.

Insect-Mediated Contaminant Flux at the Land-Water Interface: Are Ecological Subsidies Driving Exposure or Is Exposure Driving Subsidies?

Insect-Mediated Contaminant Flux at the Land-Water Interface: Are Ecological Subsidies Driving Exposure or Is Exposure Driving Subsidies?

Characterizing the Relationship between the Sediment Grain Size and the Shoreline Variability Defined from Sentinel-2 Derived Shorelines

Sediment grain size is a fundamental parameter conditioning beach-face morphology and shoreline changes. From remote sensing data, an efficient definition of the shoreline position as the water–land interface may allow studying the geomorphological characteristics of the beaches. In this work, shoreline variability is defined by extracting a set of Satellite Derived Shorelines (SDS) covering about three and a half years. SDS are defined from Sentinel 2 imagery with high accuracy (about 3 m RMSE) using SHOREX. The variability is related to a large dataset of grain-size samples from the micro-tidal beaches at the Gulf of Valencia (Western Mediterranean). Both parameters present an inverse and non-linear relationship probably controlled by the beach-face slope. High shoreline variability appears associated with fine sands, followed by a rapid decrease (shifting point about medium/coarse sand) and subsequent small depletions as grain sizes increases. The relationship between both parameters is accurately described by a numerical function (R2 about 0.70) when considering samples at 137 open beaches. The definition of the variability is addressed employing different proxies, coastal segment lengths, and quantity of SDS under diverse oceanographic conditions, allowing to examine the effect they have on the relation with the sediment size. The relationship explored in this work improves the understanding of the mutual connection between sediment size, beach-face slope, and shoreline variability, and it may set up the basis for a rough estimation of sediment grain size from satellite optical imagery.

Cumulative Impacts of Land Cover Change and Dams on the Land–Water Interface of the Tocantins River

Riparian vegetation performs important ecosystems services, improving water quality, mitigating erosion, and maintaining regional plant and animal biodiversity. Regular annual flooding maintains riparian forests through an intermediate disturbance regime. In response, seasonally flooded vegetation has developed adaptations for seed dispersal and gas transfer to survive and reproduce while undergoing periods of flooding. In the Amazon, a dam building boom threatens the integrity of riparian vegetation by moving riparian corridors into dry-adapted ecosystems and reducing downstream flooding of riparian areas. Additionally, the region is undergoing intense development pressure resulting in the conversion of native riparian vegetation into agriculture. In this study, we measure how the installation of six large dams on the Tocantins River, coupled with land cover change from native forest and savanna to cattle pasture, has changed the land–water interface of this region. Using land cover data provided by MapBiomas, we quantified land cover change from 1985 to 2018 and measured changes in the riparian areas of the still free-flowing areas of the Tocantins River, riparian areas surrounding reservoirs, and in-stream vegetation dynamics. We found that deforestation in the riparian areas of the Tocantins River downstream of the dams is occurring at a higher rate than deforestation in the watershed. Additionally, reservoir filling resulted in creating hundreds of square kilometers of new riparian areas, pushing the riparian zone away from forest-dominated ecosystems into savanna-dominated areas. The quantity of in-stream vegetation throughout the study was dynamic and initially increased after damming before declining for the last decade of the study. Changes to native land cover in riparian areas of the Tocantins River threaten the integrity of ecosystem services provided by riparian vegetation and are likely to lead to further degradation of these areas.

Does Flooding Define the Aquapelago? Constructing Venice’s flood disaster risk personality

Part of Venice’s character and appeal is sometimes constructed and construed as being not just about water, but also about the role which flood management plays, especially avoiding floods. A ‘disaster risk personality’ is created regarding water-land interaction, based mainly on avoiding inundation. This paper explores the construction of this approach for Venice’s flood disaster risk personality through a conceptual examination of Venice as an aquapelago to understand water-land links and separations. With this baseline, three decision-making lessons for Venice’s flood disaster risk personality are detailed: (i) the dynamicity of the water-land interface and hence the aquapelago, (ii) the impact of structural approaches on disaster risk personality, and (iii) the implications of submergence. While non-structural approaches to flood risk management tend to have the best long-term successes in averting flood disasters, Venice has chosen the opposite approach of constructing a large barrier, substantively changing its disaster risk personality. This choice is not inherently positive or negative, with the desirability and usefulness being subjective and based on the (flood) disaster risk personality sought for the locale.

Distribution and diversity of meiofauna along an aquatic-terrestrial moss ecotone

Summary This study provides first insights into the moss-dwelling meio-invertebrate community inhabiting mosses collected from underwater, splash-water and adjacent terrestrial habitats along a Swedish lake. Additionally, changes in both species and functional diversity of the nematode community were followed. Total meio-invertebrate mean densities and biomass peaked at 10 644.2 ± 2391.8 individuals (g dry weight (DW) moss)−1 and 14 199.3 ± 5037.3 μg DW (g DW moss)−1 underwater, 1 m away from the shoreline, where the community was strongly dominated by rotifers, followed by nematodes. Total invertebrate biomass in terrestrial mosses was much lower, indicative of a significantly higher carrying capacity of moss patches in aquatic environments, which provide a high level of resource turnover as well as a buffer against desiccation and extreme temperature fluctuations. We found a total of 74 nematode species and maximum diversity was attained 1 m away from the shoreline and at the splash-water zone. The underwater mosses at the shoreline thus housed the most diverse and abundant assemblages of meio-invertebrates, suggesting they may play an important ecological role at the land-water interface. Evidenced by the multiple shifts in dominance, our study clearly showed that feeding types differed between habitats. The taxonomic and functional segregation of the nematode community along the ecotone further indicated that the composition of nematode species assemblages has the potential to mirror the ecological changes of the study site, even at small scales.

Reconciling carbon-cycle processes from ecosystem to global scales.

Understanding carbon (C) dynamics from ecosystem to global scales remains a challenge. Although expansion of global carbon dioxide (CO2) observatories makes it possible to estimate C‐cycle processes from ecosystem to global scales, these estimates do not necessarily agree. At the continental US scale, only 5% of C fixed through photosynthesis remains as net ecosystem exchange (NEE), but ecosystem measurements indicate that only 2% of fixed C remains in grasslands, whereas as much as 30% remains in needleleaf forests. The wet and warm Southeast has the highest gross primary productivity and the relatively wet and cool Midwest has the highest NEE, indicating important spatial mismatches. Newly available satellite and atmospheric data can be combined in innovative ways to identify potential C loss pathways to reconcile these spatial mismatches. Independent datasets compiled from terrestrial and aquatic environments can now be combined to advance C‐cycle science across the land–water interface.

An Improved Water-Land Discriminator Using Laser Waveform Amplitudes and Point Cloud Elevations of Airborne LIDAR

Zhao, X.; Wang, X.; Zhao, J., and Zhou, F., 2021. An improved water-land discriminator using laser waveform amplitudes and point cloud elevations of airborne LIDAR. Journal of Coastal Research, 37(6), 1158–1172. Coconut Creek (Florida), ISSN 0749-0208. Laser waveforms or point clouds of airborne LIDAR are used to distinguish water and land. However, false alarms often occur in coastal areas with complex environments when laser waveforms are used. Elevations of three-dimensional (3D) point clouds can be used to help discriminate ocean and land but fail to identify inland waters. An improved water-land discriminator that uses laser waveform amplitudes and point cloud elevations is proposed in this study. First, 3D point cloud elevations derived using infrared (IR) laser are used as features to conduct ocean-land discrimination with fuzzy c-means clustering. Second, amplitudes of IR laser waveforms are used to identify inland waters from land derived by ocean-land discrimination. The proposed method is applied to data collected using Optech coastal zone mapping and imaging LIDAR (CZMIL). Land boundary derived from digital orthophoto map is used as a reference to evaluate different water-land discriminators. Results showed that consistency of the water-land interface derived using the improved water-land discriminator is higher with the reference interface than that derived by traditional waveform saturation, waveform clustering, and 3D point cloud methods. Overall accuracy of water-land points discriminated via waveform saturation, waveform clustering, 3D point cloud, and improved water-land discriminator is 93.80%, 93.84%, 95.66%, and 99.27%, respectively. High accuracy of the water-land interface and points indicates the effectiveness of the improved water-land discriminator for Optech CZMIL.

Conversion Of Natural Landscape By Unplanned Urbanization: Study The Change Of Traditional Land-Water Interface In The Eastern Periphery Of Dhaka

Dhaka, a low laying city in the world’s most extensive delta system, is rapidly grabbing its mandatory natural landscape into the built-up area. This deltaic city’s water resources once played an essential role in structuring settlement patterns and keeping the overall hydrological, ecological, and environmental equilibrium. Eastern Fringe, the crucial natural, spontaneous territory of the Dhaka Metropolitan Area (DMA) to prevent the city’s flooding problems and environmental degradation, is rapidly converting from traditional homestead to urbanised land. The city’s present development activities for this part and the entire city do not respect this profound geo-morphological nature of the territory or consider the traditional land-water relationship with the settlement. This paper will analyse the land-use conversion in the study area, focusing on the land-water interface to identify the natural landscaped change for the built-up area. The article will first elaborate on the study area's enriched land-water system and its local integration in the land-water interface. It will also explain the importance of natural land-water resources for the city’s hydro-ecological. Finally, through ArcGIS and Google Earth Image analysis, it will discover the rapid loss of natural land-water resources, its process of conversion and associated environmental degradation due to land-cover alteration in the focus area. This paper will give the importance to reinstall the traditional land-water relationship in the rapidly growing urban areas to check environmental degradation.

Automatic Shoreline Detection from Video Images by Combining Information from Different Methods

Properly registering the time evolution of the shoreline—the coastal land-water interface—is a crucial issue in coastal management, among other disciplines. Video stations have shown to be powerful low-cost tools for continuous monitoring of the coast in the last 30 years. Despite the efforts of the scientific community to get algorithms able to properly track the shoreline position from video images without human supervision, there is not yet an algorithm that can be recognized as fully satisfactory. The present work introduces a methodology to combine the results from different shoreline detection algorithms so as to obtain a smooth and very much improved result when compared to the actual shoreline. The output of the introduced methodology, which is fully automatic, includes not only the shorelines at all available times but also a measure of the quality of the obtained shoreline at each point (called self-computed error). The results from the studied beaches—located in the region of Barcelona city (Spanish Mediterranean coast)—show that such self-computed errors are in general good proxies of the actual errors. Using a certain threshold for the self-computed errors, the final computed shorelines have RMSE (Root Mean Squared Errors) that are in general smaller than 2.5 m in the great majority of analysed images, when compared to the manually digitized shorelines by three expert users. The global RMSE for all dates and beaches is of 1.8 m, with a mean bias &lt;1 m and percentage of retrieval success &gt;95% of the points.

T-Phases Observed at the Ionian Seafloor: Seismic Source and Bathymetric Effects

AbstractT-waves are acoustic waves generated by earthquakes at the land–water interface. They can propagate efficiently for thousands of kilometers within the ocean’s low-velocity waveguide—the SOund Fixing And Ranging (SOFAR) channel. In the present work, we studied T-waves that propagate in the Ionian basin and are generated by regional earthquakes (epicentral distance &amp;lt;1000 km) located in the Hellenic Arc (Greece). The Ionian Sea is a small basin that has strong bathymetric variations and is limited at its western edge by a steep continental slope—the Malta escarpment. T-waves from Greece were recorded by a broadband seismometer onboard one of seafloor-observing units of the Western Ionian Regional Facility of EMSO—European Multidisciplinary Seafloor and water column Observatory Research Infrastructure (see Data and Resources) deployed in the western Ionian Sea (Italy) at about 2100 m water depth. By studying the particle motion and T-phase energy flux (TPEF) of the T-waves recorded at the observatory, we find that the western Ionian Sea bathymetry is an efficient reflector for T-waves within the SOFAR channel. To investigate whether factors other than T-wave path effects drive TPEF levels, we also study the source part of the T-wave generation process.

What We Do in the Shallows: Natural and Anthropogenic Seafloor Geomorphologies in a Drowned River Valley, New Zealand

The shallow marine environment represents a region of high biological productivity, ecological diversity, and complex oceanographic conditions, and often supports various human activities and industries. Mapping of the seafloor in shallow marine environments reveals seafloor features in detail, shedding light on a range of natural and anthropogenic processes. We present a high-resolution (2-m) multibeam dataset, combined with geologic samples that reveals a complete map of the seafloor from the land-water interface to ~350 m water depth within Queen Charlotte Sound/Tōtaranui (QCS) and Tory Channel/Kura Te Au (TC), Marlborough Sounds, New Zealand. These data reveal that the seafloor geomorphology and distribution of natural and anthropogenic features varies spatially from the inner QCS to the Cook Strait. Tidal currents play a large role in the erosion, transport, and deposition of sediments in QCS and TC. The distribution and depth of seafloor scouring suggests that tidal flow is locally intensified by coastal geometry and bathymetric barriers, resulting in concentrated scouring where tidal flow is restricted or redirected. In addition, superimposed bedforms reflect localised variations in flow direction that have likely developed across a range of spatial and temporal scales. Evidence for extensive seafloor fluid expulsion is preserved in >8500 pockmarks mainly located within the inner and central QCS. The size and spatial distribution of pockmarks suggest multiple fluid sources in the region. The cumulative anthropogenic footprint on the seafloor within QCS represents 6.4 km2 (~1.5%) of the total seafloor area and is predominantly related to maritime activities including anchor dragging (47.5%) and mooring blocks (24%). This study provides a unique example of the information that can be revealed by a comprehensive survey programme that mapped from the land-water interface to the subtidal zone. Results presented in this study form a robust basis upon which to develop improved hydrodynamic models and benthic habitat maps and to assess the full extent of anthropogenic activities in the shallow marine realm.

Quantifying Vegetation and Landscape Metrics with Hyperspatial Unmanned Aircraft System Imagery in a Coastal Oligohaline Marsh

Billions of dollars are projected to be spent on restoration projects along the northern Gulf Coast which will require efficient monitoring at both landscape and project-specific scales. Recent developments in unmanned aircraft systems (UAS) have sparked interest in the ability of these “drones” to capture hyperspatial imagery (pixel resolution < 10 cm) that resolves individual species and produces accurate data for monitoring programs in coastal landscapes. We present a case study conducted at Coastwide Reference Monitoring System (CRMS) station 0392, a Spartina patens–dominated, oligohaline coastal marsh in Terrebonne Parish, Louisiana. Results demonstrate the ability of UAS technology to collect hyperspatial, multispectral aerial images in a coastal wetland, and to produce very-high-resolution orthomosaics and digital elevation models. We then used object-based image analysis (OBIA) techniques to (1) delineate the land–water interface, (2) classify composition by dominant species, and (3) quantify average plant height by species. Model results were validated with traditional on-the-ground CRMS vegetation surveys. Results suggest that OBIA methods can overcome the spectral variability of hyperspatial datasets, quantify uncertainties in conventional techniques, and provide improved estimates of wetland vegetation cover and species composition. These methods scale conventional plot-level coverage values to data-rich landscape-level models and provide useful tools to monitor restoration performance, landscape changes, and ecosystem services in coastal wetland systems.

Small streams dominate US tidal reaches and will be disproportionately impacted by sea-level rise

Rivers and streams represent <0.6% of the Earth's land surface but play a disproportionately large role in global biogeochemical cycles and provide locally relevant ecosystem services. However, knowledge of how rivers influence material budgets and ecosystem services has major gaps due to the lack of explicit consideration of tidally-influenced reaches. Focusing on the conterminous US, we provide a foundation for understanding the role of tidal streams. We find that 66% of tidal stream length is contributed from low order streams (< 4th order), and that terrestrial ecosystem production in low-lying coastal zones is 30% greater than in adjacent terrestrial ecosystems. This prevalence of small streams indicates that small coastal watersheds dominate tidally influenced spatial domains. Furthermore, we find that relative sea-level rise (RSLR) will have a disproportionate impact on low order tidal streams and their terrestrial interfaces - 1 m RSLR will decrease the tidal stream land-water interface by 17% and the total surface area of US tidal streams by 31%. Upstream reaches of tidal zones will be extended in response to RSLR, but gains will be more than offset by coastal losses because topographic gradients become steeper moving inland, and accretion rates may not keep pace with RSLR. These results highlight previously unrecognized dominance, high productivity, and disproportionate future loss of low-order coastal ecosystems. This indicates a critical need to focus research on small tidal stream systems under contemporary and future conditions.

Social Mobilization to Reduce Vulnerability to Adverse Impacts of Climate Change in the Niger Delta Region of Nigeria

The extensive land-water interface (320 kilometres) between the Niger Delta and Atlantic Ocean exposes the coastal and low-lying areas to climaterelated sea-level rise. This is associated with hazardous ecological changes and unsustainable communities, compounded by social injustice, civil strife, conflicts, insecurity, and the overwhelmingly negative overall effects on health by the environmental degradation caused by petroleum oil spillages, extensive gas flaring, and frequent disastrous gas explosions. This paper focuses on reviewing the vulnerability of the Niger-Delta region to the adverse effects of climate change, and it also explored the potentials of social mobilization to change collective behaviour towards reducing the carbon footprints, build public support for low-carbon climate change policies including focus on green economy, promote ecological resilience, and build sustainable communities. In the context of climate change, the goal of social mobilization is the application of science and policy to ‘turn vulnerability to adverse impacts of climate change to resilience’. In the Niger Delta region, social mobilization can assist communities, individuals, groups, and organizations to learn, understand the causes and effects of climate change, and turn vulnerability into resilience. This can be achieved through selfreliance and participation in the planning, implementation, monitoring, and evaluation of sustainable mitigation measures and strategies for adaptation to climate change. Social mobilization enables ‘bottom-up’ informal, genderdiverse, youth-sensitive, organizational and institutional initiatives for ‘good governance’, political mobilization against social injustice, and the development of alternative forms of conflict resolution. Efficient social mobilization enables social inclusion of all stakeholders, irrespective ofsocioeconomic status, to participate in the decision-making process, and also builds skills and capacity to lead happy and healthy lives. Federal and state government policies, in the Niger Delta region, must ensure that their political agenda for mitigation measures and strategies for adaptation to climate change adopts social mobilization as an effective tool to turn ‘vulnerability to resilience’ through a multi-sectoral, multi-jurisdictional, and multidisciplinary participatory approach.

An efficient protocol for accurate and massive shoreline definition from mid-resolution satellite imagery

Satellite images may constitute a useful source of information for coastal monitoring as long as it is possible to manage them in an efficient way and to derive precise indicators of the state of the beaches. In the present work, SHOREX system is employed for managing and processing Landsat 8 and Sentinel 2 images to automatically define the instantaneous shoreline position at sub-pixel level. Between the years 2013 and 2017, 91 satellite-derived shorelines (SDS) were assessed by comparing with high-resolution shorelines obtained simultaneously through video-monitoring. The analysis allowed identifying the combination of parameters to perform the extraction algorithm with the highest accuracy. Furthermore, an efficient self-contained workflow is proposed, more robust and independent from inaccuracies in the approximate input line and from multiple morphological and oceanographic issues that may condition the radiometric response near the shore. An iterative procedure ensures firstly a suitable kernel of analysis representing the water-land interface to get, afterward, the definition of the sub-pixel shoreline with high accuracy (below 3 m RMSE).

Research Progress on Coastline Change in China

Fan, Q.; Liang, L.; Liang, F., and Sun, X., 2020. Research progress on coastline change in China. In: Zheng, C.W.; Wang, Q.; Zhan, C., and Yang, S.B. (eds.), Air-Sea Interaction and Coastal Environments of the Maritime and Polar Silk Roads. Journal of Coastal Research, Special Issue No. 99, pp. 289–10. Coconut Creek (Florida), ISSN 0749-0208.A coastline is an ecologically sensitive area at the land–water interface. Coastline change has an important impact on regional ecology, economy, and society. China has a long coastline and its coastal zone is among the fastest developing regions in the world. An effective understanding of Chinese coastline changes can aid sustainable development in China and surrounding areas. In this paper, we reviewed the literature of coastline changes in China through the end of 2018. Through literature analysis, the coastline change research in China can be divided into three stages: a start-up stage, an exploration period, and a developmental period. Ancient maps, traditional actual trace measurements, ancient sea level markers, remote-sensing images, and Light Detection and Ranging technology are the main data sources of coastline research. From the research content, the coastline change literature in China mainly focuses on the analysis of space–time changes and coastline driving forces. There is also limited literature on coastline change prediction, which mainly refers to the shape and location of coastline change. The next stage, the relationship between coastline change and the environment, is the focus of future research. This study provides a relatively comprehensive review of coastline changes in China that may have a certain significance for the study of these changes in China and perhaps the world. It can serve as a basis for developing scientific and reasonable policies for sustainable development in coastal zones.