Low Water Mark Research Articles

Hydrochemical characteristics of left-bank tributaries of the Dniester within Ternopil Oblast


 
 
 The purpose of this article is to study the chemical composition of water and the hydrochemical regime of the left-bank tributaries of the Dniester within the Ternopil Oblast at 9 monitoring sites on the Zolota Lypa, Koropets, Strypa, Seret, Nichlava, and Zbruch Rivers. Water quality monitoring data from the State Agency of Water Resources of Ukraine for the period from 1993 to 2020 were used. The hydrographic assessment of the territory following the Water Code of Ukraine showed the presence of two medium-sized rivers (Seret and Zbruch) and four small rivers among the studied rivers. The chemical composition of the water was analyzed by the following groups of components: major ions and water salinity; physicochemical parameters; and biogenic components (nitrogen and phosphorus compounds). It was found that the water of most studied rivers is calcium bicarbonate by hydrochemical type. The water of the Nichlava River is calcium bicarbonate-sulfate. The average annual salinity of the water of the studied rivers varies from 476 mg∙dm-3 to 699 mg∙dm-3. It was determined that the water of most rivers is moderately fresh in terms of mineralization. The water of the Nichlava River is fresh with high mineralization. The hydrochemical regime of rivers is generally related to the hydrological regime. The minimum concentrations of the main ions and salinity values of the studied rivers are observed during the summer-autumn low water mark, which is explained by the significant amount of precipitation and the presence of floods during this period. In winter, the maximums of these indicators are observed. Among the biogenic compounds (ammonium, nitrite, nitrate, phosphate), the clearest manifestation of the hydrochemical regime was recorded for nitrate. The minimum NO3– concentrations are observed in the summer and autumn low-water periods when nitrates are consumed for the development of aquatic plants. In the autumn period, with the death of aquatic plants, nitrates accumulate, and during the winter low water, their maximum average content is observed. The analysis of the monitoring system of the State Agency of Water Resources of Ukraine for the content of the studied components in the water of the left-bank tributaries of the Dniester over a multi-year period for all samples showed that their concentrations were within the regulatory requirements, except for one case. Particularly, in the water of the Nichlava – Borshchiv River, an ammonium concentration of 15 mg∙dm-3 was recorded, which was 7.5 times higher than the standard (August 2, 2000).
 
 

The Western crescent rises — a verticality dimension in Louisiana’s mixed legal space

The legal literature discussing mixed jurisdictions has mainly focused on horizontal law mixtures, especially those involving the Civil Law and the Common Law. Harnessing the legal questions raised by land loss in Louisiana’s landscape of waterbodies as a case study, this Article illustrates how American federal law, whether constitutional, statutory or judge-made, has interacted with the allocation of property rights under Louisiana state law. Among the various stakeholders, the legal implications of erosion and subsidence play out in two relationships: firstly, the relationship between private property owners and the State of Louisiana with regard to lakeshore, banks of rivers, bays and streams, and seashore; and secondly, the relationship between the State of Louisiana and the Federal Government with regard to their rights in the territorial sea. In the first relationship, the equal footing doctrine enunciated by the U. S. Supreme Court declares that, because the original thirteen states in the American Union owned the land under their natural navigable water bodies, subsequent entrants would likewise take ownership of such land. Based on the federal equal footing doctrine, Louisiana state law has enjoyed a margin of maneuver to make its own dispositions for the lakeshore, the bank of a river, bayou or stream, and the seashore. Also, when allocating ownership under state law, Louisiana courts have traditionally looked to the federal admiralty definition of navigability. The federal-state interface dominating the second relationship has come to be known as the “tidelands controversy” over submerged lands, along with the wealth of resources, seaward of the low-water mark on Louisiana’s coast. This led to a dance between the U. S. Supreme Court, the U. S. Congress and the State of Louisiana. Although Louisiana ultimately secured jurisdiction up to three nautical miles, its maritime belt still does not match Texas and Florida’s boundaries.

Characterizing groundwater salinity patterns\xa0in a coastal sand aquifer\xa0at Magilligan, Northern Ireland,\xa0using geophysical and geotechnical methods

Tidal forcing influences groundwater flow and salt distribution in shallow coastal aquifers, with the interaction between sea level variations and geology proving fundamental for assessing the risk of seawater intrusion (SI). Constraining the relative importance of each is often confounded by the influences of groundwater abstraction and geological heterogeneity, with understanding of the latter often restricted by sampling point availability and poor spatial resolution. This paper describes the application of geophysical and geotechnical methods to better characterize groundwater salinity patterns in a tidally dominated ~ 20 m thick sequence of beach sand, unaffected by groundwater abstraction. Electrical resistivity tomography (ERT) revealed the deposit to consist of an upper wedge of low resistivity (< 3 Ωm), reaching over 8 m thick in the vicinity of the low water mark, overlying a higher resistivity unit. Cone penetrometer testing (CPT), and associated high-resolution hydraulic profiling tool system (HPT), coupled with water quality sampling, revealed the wedge to reflect an intertidal recirculation cell (IRC), which restricts freshwater discharge from a relatively homogeneous sand unit to a zone of seepage within the IRC. The application of CPT and HPT techniques underscored the value of geotechnical methods in distinguishing between geological and water quality contributions to geophysical responses. Survey results have permitted a clear characterization of the groundwater flow regime in a coastal aquifer with an IRC, highlighting the benefit of combining geophysical and geotechnical methods to better characterize shallow SI mechanisms and groundwater flow in coastal hydrogeological environments.

Baseline Study of Trace Element Concentrations in Sediments of the Intertidal Zone of Amazonian Oceanic Beaches

Analyzing the presence and quantifying trace elements is of paramount importance to understand natural environmental processes and monitor the degree of anthropogenic disturbance to mitigate impacts already caused. Here, we aimed to establish a baseline of the trace elements profile and concentrations in sandy sediments of intertidal areas of three Amazonian beaches (Brazil). For each beach, sediments were collected from three different sectors (south, center, and north) and five shoreline distance levels (from the high- to the low-water mark), totalizing 15 samples per beach. The concentration of the different trace elements (Mg, Al, P, S, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Br, Rb, Sr, Y, Zr, Cd, Sn, I, Hg, and Pb) was determined by Total reflection X-ray Fluorescence spectrometry. Sediment was also characterized for its grain size, organic matter, and pH. To assess possible enrichment due to anthropogenic activities we compared trace element levels with the values for the Earth’s crust and calculated pollution indexes: geoaccumulation index (Igeo), ecological risk index (RI), contamination factor (CF), pollution load index (PLI), and sediment quality guideline (SQG), threshold effects level (TEL) and probable effects level (PEL). Individual trace metal concentrations did not vary significantly between beaches, sectors, or sample levels, evidencing a homogeneity of trace elements composition and concentrations across this environment. Igeo indicated 62.2% of the sampling stations uncontaminated, 20.0% from uncontaminated to moderately contaminated, and 4.44% (two sampling stations) strongly contaminated, the same two areas classified as high ecological risk by RI. Most of the sampling points presented low CF. Cadmium and Hg were the only elements that showed moderate to very high values of CF. According to the SQGs, 77.7 and 8.8% of the sampling points presented values above the moderate threshold effect level (SQG-TEL) and probable effect level (SQG-PEL), respectively. All points were classified as non-polluted according to the PLI. Our results show that the three beaches present safe levels of almost of the elements demonstrating the good state of preservation. Most of the indexes classified the sampling points as non-polluted, except for Cd and Hg in a few specific sampling points.

Distribution of shallow water delta sand bodies and the genesis of thick layer sand bodies of the Triassic Yanchang Formation, Longdong Area, Ordos Basin

Abstract Based on the cores from 47 wells and logging data of 130 wells, the main types of sand bodies in the shallow water delta of the Chang 82 sub-member in the Triassic Yanchang Formation, Longdong Area, Ordos Basin were comprehensively analyzed, the distribution characteristics of sand bodies more than 20 m thick were identified, and the genetic types of the thick sand bodies were sorted out. In this region, thick-bed sand bodies can be divided into two types according to the shape and position: type 1 is the sand body in wide strip and is distributed between the average high water mark and the average low water mark; type 2 is distributed on both sides of the average low water mark and is in irregular lump shape. Based on the principle of the volume distribution of sediments and the change rule of accommodation space, the genetic models of two types of thick-bed sand bodies in the Chang 82 sub-member are superimposed distributary channel sand bodies in high accommodation space and superimposed composite sand bodies in low accommodation space.

Sideswipes and Backhanders: Abolition of the Reasonable Chastisement Defence in South Africa

Abstract This article reviews the abolition of the defence of reasonable chastisement by the South African Constitutional Court on the grounds that it infringes the Constitution. After detailing the history of the abolition of corporal punishment in a democracy with the Constitution as supreme law, the article dissects the reasoning of the Constitutional Court. It argues that judgment in Freedom of Religion South Africa v Minister of Justice and Constitutional Development (hereafter FORSA), whilst overall positive in its result, is probably a low water mark in the development of children’s rights jurisprudence in South Africa. There are a number of inadequacies and strangely deferential statements in the FORSA decision. Whilst inescapably coming to the constitutionally correct decision, the reluctance of the Court to reach this point, and its desire to accommodate the religious and cultural beliefs of the appellants, is evident. The way forward has, as a result, been left rather obscure.

Regularly-spaced grooves on shore platforms in north Northumberland, UK

Unusual regularly-spaced grooves are found between low water mark (LWM) and high water mark (HWM) on several shore platforms in north Northumberland. References in the literature are sparse, so data were collected to establish the nature of the grooves and to elucidate the processes that might have formed them. Groove formation is confined to strata with widely spaced bedding planes on shore platforms dipping at no more than 5° towards the sea. The grooves are symmetrical, bifurcation is common and grooves on sandstones are deeper and more sinuous than those on limestones. Grooves at mid-tide levels are wider than grooves near LWM and HWM and the trend of the grooves is not related to joint trends. The process that has formed the characteristically smooth surfaces of the grooves is considered to be abrasion by sand and pebbles carried by waves in the surf zone of the shore platform. The width of the grooves is remarkably regular, and it is suggested that this may be due to the effects of the increase in incident wave energy given by edge waves.

MIKOKO: A Data Sharing Platform On Kenyan Mangrove Species

The Mangrove ecosystem offers a range of benefits and opportunities for local and national economic development such as fisheries, shoreline stability, and resource sustainability hence they should be protected and conserved. In Kenya Mangroves were declared government reserve forests by the Proclamation No. 44 of 30th April 1932, and later by Legal Notice No. 174 of 20th May 1964. Under this “Gazette Notification for Mangrove Forests in Kenya” all land between high water and low water marks (ordinary spring tides) are described as mangrove areas. These forests cover about 61,279ha representing approximately 3% of the natural forest cover or less than 1% of the national land area. Mangrove forests are found in tidal estuaries, creeks, and protected bays along the 536 km long Kenyan coastline that extends from the Kenya-Tanzania border in the south to the Kenya-Somalia border in the north; between latitudes 1°40΄S and 4°25΄S and longitudes 41°34΄E and 39°17΄E. Mikoko (Mangrove in Swahili) is the first project specifically developed for mangrove areas in Kenya. Driven by the Kenya Forest Service, the project takes into account the recommendations of the National Mangrove Ecosystem Management Plan 2017-2027. For effective management of mangroves in the country, the Plan is organised around six programmes including; forest conservation and utilization; fisheries development and management; community; tourism development; research and education; and human resource and operations. These programmes prescribe measures for rehabilitation, conservation, and sustainable management of mangrove ecosystems in Kenya. Implementations of this Plan will be led by Kenya Forest Service (KFS); but will also include other key actors such as Kenya Wildlife Service, State Department of Fisheries, Research Institutions, Academia and Community Forest Associations through a specially constituted National Mangrove Advisory Committee. The project is for a 2-year period during which it shall develop an effective system for management of mangrove resources in Kenya. This will be done through the development of management prescriptions, skills improvement and provision of adequate infrastructure as recommended by the mangrove plan. Biodiversity information on mangroves, covering species descriptions and distribution, is essential for understanding the ecology and distribution of this endangered ecosystem and its management. Nowadays, very few is done in that domain. If the mangroves location are well know, it's not the case regarding the species distribution. Citizen science is a way to address this important issue. MIKOKO, a French FSPI funded project, is focused on Kenya to develop species information systems on mangrove species. Mikoko aims to assimilate knowledge through its participatory portal to strengthen a science and technology network of stakeholders such as scientists and parataxonomists in the African region. The portal platform will contain a Citizen Science module, a graphic driven species identification module, a species pages module conforming to Species Profile Model and a spatial module. Subscribing to open data paradigm, all the data on the portal will be covered by Creative Commons license framework. Mobile applications for identifying 60 plant species and contributing to citizen science module will be deployed. The oral presentation will expose the portal features and related apps seeking participation from the environmentalists from the African region.

LoWVR: Low Overhead Watermark based Vehicle Revocation Scheme in VANET

Background and Objective: The inter-vehicle communication is a potential issue for improving road safety, detecting traffic accidents, etc. in vehicular ad hoc network. The communication among the vehicles in VANET must be protected from the dissemination of message by unauthorized vehicles and the alteration of the message by misbehaving vehicles. Methods: In this paper, a low overhead digital watermark based vehicle revocation scheme is proposed. The sender vehicle generates a message and a random number after observing an event. It generates a deformed version of the generated message and message digest, and concatenates them. The watermark bits are generated by the sender vehicle from its unique identification and the random number. The sender vehicle embeds the watermark bits in the concatenated form of the message digest and deformed version of the generated message, and broadcasts the embedded message for its neighbours. The neighbour vehicles extract the required information from the received embedded message to verify the authentication of the sender vehicle and to identify whether the sender vehicle is an alteration attacker. It revokes unauthentic vehicles and vehicles that are identified as alteration attacker from vehicular ad-hoc network without any dependency on the trusted third party. The cracking probability and cracking time are used to measure the robustness of the scheme. The cracking probability and cracking time are measured to set the design guideline regarding the size of the watermark. The qualitative performance of the scheme is measured in terms of storage, communication and computation overhead. The significant reduction of all such overheads is observed by comparing the qualitative performance of the proposed scheme with two existing schemes. Conclusion and Results: Thus, the proposed scheme is a low overhead solution of securing vehicular ad hoc network. Performance of the scheme is also studied quantitatively in terms of the time of verifying vehicle authentication at the receiving end, delay in message dissemination at the sending end and delay in message reception at the receiving end. The quantitative performance is also compared with two of the existing schemes.

Assessment of movements and habitat use of Salmo opimus in Fırnız stream, river Ceyhan of Turkey using radio telemetry techniques

This study was carried out to provide information about movement and habitat use by an endemic Salmonid species (Salmo opimus Turan et al. Ichthyol Explor Freshw 23: 219–236, Turan et al. 2012) in Firniz Stream, a tributary of River Ceyhan in Turkey, using manual tracking as a radio telemetry technique. During the study, 19 of the 23 tagged trout were relocated by eight to 20 times (mean: 15 relocations per fish) in Firniz Stream. The time between the tracking surveys and relocations varied from 21 to 44 days (mean: 30 days) and the mean distance between relocations was 151 m (26 to 881 m). Tagged trout showed a distribution within a distance of 9350 m in Firniz Stream. 95% of the relocations clustered at a distance of 4500 m, while 75 and 50% of them were distributed at a distance of 1935 m and 1488 m, respectively. The linear home range of the individual ranged from 199 to 5087 m (mean 792 m), whereas mean 95% Kernel Density Home Range (KDHR), 75% KDHR, and mean core range (50% KDHR), were 632 m, 477 m and 290 m, respectively. The depths and velocities of the locations where tagged trout occurred varied from 20 to 185 cm (mean depth: 43 cm) and 11 to 240 cm/s (mean velocity: 45.9 cm/s). There was no correlation between fish size and depth and fish size and velocity. Hydropower stations and trout farms negatively affected movement of the brown trout in the stream. The fish passage in Firniz Hydropower Station (HPP) is inefficient due to low water mark downstream. Thus, all the obstructions that prevent fish movements must be arranged to enable fish passage in Firniz Stream in order to preserve the brown trout population in the stream.

A New Fractal Watermarking Method for Images of Text

A new method, using the orthogonal fractal coding is developed for fractal watermarking of high contrast, low-density images of texts. In this method, image is divided into one pixel height sub-images. Each sub-image is coded separately using the orthogonal fractal coding technique. A binary watermark is re-ordered using a chaotic sequence. The binary watermark is inserted into the range block means of fractal codes. This fractal code is further decoded to obtain the watermarked image. The watermark sequence is retrieved by comparing the original image and the watermarked code. The extracted watermark is re-ordered using the key of the chaotic sequence. The method is robust against JPEG and noise attacks and has a very low watermark visibility.

Predominant Atmospheric and Oceanic Patterns during Coastal Marine Heatwaves

As the mean temperatures of the worlds oceans increase, it is predicted that marine heatwaves (MHWs) will occur more frequently and with increased severity. However, it has been shown that variables other than increases in sea water temperature have been responsible for MHWs. To better understand these mechanisms driving MHWs we have utilised atmospheric (ERA-Interim) and oceanic (OISST, AVISO) data to examine the patterns around southern Africa during coastal (<400 m from the low water mark; measured in situ) MHWs. Nonmetric multidimensional scaling (NMDS) was first used to determine that the atmospheric and oceanic states during MHW are different from daily climatological states. Self-organising maps (SOMs) were then used to cluster the MHW states into one of nine nodes to determine the predominant atmospheric and oceanic patterns present during these events. It was found that warm water forced onto the coast via anomalous ocean circulation was the predominant oceanic pattern during MHWs. Warm atmospheric temperatures over the subcontinent during onshore or alongshore winds were the most prominent atmospheric patterns. Roughly one third of the MHWs were clustered into a node with no clear patterns, which implied that they were not forced by a recurring atmospheric or oceanic state that could be described by the SOM analysis. Because warm atmospheric and/or oceanic temperature anomalies were not the only pattern associated with MHWs, the current trend of a warming earth does not necessarily mean that MHWs will increase apace; however, aseasonal variability in wind and current patterns was shown to be central to the formation of coastal MHWs, meaning that where climate systems shift from historic records, increases in MHWs will likely occur.

Spread Spectrum Watermark Detection on Degraded Compressed Sensing

This letter proposes a robust spread spectrum image watermark detection on compressed sensing (CS) measurements degraded by both multiplicative and additive noise. Watermark detection threshold is calculated first using log-likelihood ratio model. Distortion minimization problem is then formulated in terms of watermark embedding strength and the number of CS measurements under the constraint of detector reliability. A large set of simulation results show high detection probability with low false rate at low watermark power.

Counterpoint to Agardy

[Extract] It is hard to counter the perspective discussed by Tundi Agardy when the evidence she presents is so compelling and the peer-reviewed publications that she cites strengthen her concerns. So my comments below are limited to addressing a few of Tundi's specific points. Protecting the best possible area, provided it is managed effectively, can still achieve a lot for marine conservation. Readers may not be aware that when the inshore boundary of the Great Barrier Reef (GBR) Region was proclaimed in 1975, the formal boundary description was along the coastline of Queensland at low water. Low water mark constantly moves because of erosion and accretion, and is frequently underwater, so mapping it is impractical.

A golden age of general relativity? Some remarks on the history of general relativity

This article deals with the concepts “renaissance” and “low water mark between 1925 and 1955” of general relativity suggested in the literature. By empirical data, it is shown that no such period did exist. Research on general relativity continued continuously since the 1920s interrupted only by the second world war. On a broad scale, research on general relativity started only after 1945.

Two new Otoplanid species (Platyhelminthes: Rhabditophora: Proseriata)of the genera Orthoplana Steinböck, 1932 and Postbursoplana Ax, 1956 from the Tuscan coast (Italy).

Two new species of marine flatworms, collected on the sandy shores of Tuscany, are described. These species exhibit the morphological characteristics of the subfamilies Otoplaninae and Parotoplaninae ("Turbellaria", Otoplanidae), but clearly differ from other described species. Orthoplana lunae sp. nov., is characterized by a body length of 1.4-1.6 mm, distinctive features of the testes and vitellaries, the male sclerotic apparatus composed of a median stylet (48-49 μm long), and 19 spines (17-44 μm long). Postbursoplana donoraticensis sp. nov., is characterized by a body length of 1.6-1.8 mm, the distribution of testes and vitellaries, the male sclerotic apparatus composed of 10 spines (46-70 μm). This new species has a greater body length relative to other species in this genus. They were collected along the sandy shores at low water mark at Partaccia (Marina di Massa, Ligurian Sea, Italy) and Marina di Donoratico (Livorno, Ligurian Sea, Italy), respectively.

An energy-efficient and client-centric data streaming technique on smartphones

Today's users extensively download video files on their wireless handheld devices, which are inherently power constrained. Experiments have shown that video downloading accounts for a large portion of the total energy cost of downloading and playing video files. In this paper, we present a novel, energy-efficient and purely client-centric video downloading algorithm with three tunable parameters namely, buffer size, low water mark and socket-reading size. By implementing the algorithm on a smartphone and measuring the actual energy cost, we show the impacts of the three parameters on the energy cost of video downloads. By tuning the buffer size, low water mark, and socket-reading, we observed energy savings to the extent of 60%, 64%, and 63%, respectively. By incorporating our algorithmic approach into the process of video downloading, mobile application developers will be better positioned to fine-tune their apps to reduce the total energy cost of downloading large files in general.

Chronology and palaeoenvironmental reconstruction in the sub-tidal zone: a case study from Hinkley Point

Evidence from the Severn Estuary demonstrates that this region was exploited by Mesolithic hunter-gatherer-fishers (Bell, 2007). The potential for future archaeological discoveries (Bell, 2007; Webster, 2007: 273; Bell and Warren, 2013: 39), and the well-preserved palaeoenvironmental evidence in the fine-grained and organic sediments of the Somerset, Avon and Gwent Levels (Hosfield et al., 2007a: 40) makes the area of importance for archaeological study. Small quantities of worked flint have been recovered from the foreshore around Stolford, Porlock and Minehead Bay (Mullin et al., 2009; Canti et al., 1995) implying human activity in the present intertidal zone, which is further enhanced by the suggestion of possible deliberate burning of reed swamps (Jones et al., 2005) similar to that postulated in the Severn Estuary (Brown, 2005; Timpany, 2005; Bell, 2007).While considerable research has been carried out within terrestrial and intertidal contexts, remarkably little archaeological work has been undertaken below the mean low water mark (Webster, 2007: 273). The Bristol Channel and Severn Estuary has seen considerable change in sea-level since the Last Glacial Maximum (Long et al., 2002; Philips and Crisp, 2010). Extending our knowledge beyond the intertidal zone is therefore of key importance for understanding the Late Palaeolithic and Mesolithic palaeogeography of the region (Hosfield et al., 2007b).Developments in the recovery of offshore Holocene peat and sediment sequences now permit the production of multi-proxy palaeoenvironmental datasets and landscape reconstructions from submerged sample sites. This paper uses evidence from three cores, recovered from submarine peat deposits at Hinkley Point, Bristol Channel, UK, to explore the issues and challenges associated with producing radiocarbon chronologies from deeply submerged peat sequences within a marine environment. We emphasise the importance of analysis of multiple sequences to construct robust chronologies for local hydrological change and landscape reconstruction (Edwards, 2006). The need for local evidence is critical if we are to move beyond generalised and potentially misleading models of human–environment interaction (Scaife, 2011), because as this case study demonstrates, complex processes and landscape variability might have been features of even highly-localised palaeoenvironments.

Influence of saltwater wedges on irrigation water near a river estuary

Paddy fields irrigated using water from the Shinkawa River in Niigata, Japan, are subject to adverse effects associated with the occurrence of saltwater wedges in the river. The extent of saltwater intrusion in the river varies, depending on river discharge and tidal amplitude. In this study, field observations and numerical simulation of the Shinkawa River estuary were applied to ascertain the influence of saltwater wedges on paddy cultivation during the irrigation period. The saltwater wedge was surveyed using an echo-sounding profiling system (SC-3); results indicated that the longitudinal profiles of the saltwater wedge were 4.7 and 2.2 km from the river mouth sluice gate at the high water mark of spring tide and at the low water mark of neap tide, respectively. According to the vertical profiling using electrical conductivity (EC) meters at bridges crossing the river, there was a rigid interface between freshwater and saltwater with a thin halocline zone of approximately 0.25 m. These profiles were well reproduced by the one-dimensional, two-layer, unsteady flow model. The results of the model simulation and EC observation indicate that when the vertical position of the halocline rises to 1.2 m below the inlet of the water intake pumping station, the EC value rises sharply to 1,500 μs/cm, which is an unsuitable level for irrigation water. It is estimated that for about 23 % of the total irrigation period, pump operation is halted as a result of this mechanism.

VALIDACIÓN DE TECNOLOGÍAS PARA EL ESTUDIO BATIMÉTRICO DE LA ZONA INTERMAREAL DE GIPUZKOA

ABSTRACT: This project’s goal was to carry out an Airborne LIDAR Hidrographic (ALH) survey of the intertidal zone of the Gipuzkoan coast, in order to cover the supralittoral and infralittoral zones to a depth of at least 8 m. under the astronomical low water mark. In turn, it would provide continuity to the existing bathymetric and altimetric models. In the coastal strip there were data for the land area obtained with Terrestrial Laser Scanner (TLS) or Airborne Laser Scanning (ALS), and there was also a bathymetric survey of the coastal platform carried out through a MultiBeam Echosounder (MBES). Given the difficulties of surveying in the coastline, the works were set so that the ALS survey was carried out during the low tide and the MBES survey was done during the high tide, thus reducing the safety margin under the keel to the minimum. Both surveys were provided as control elements for the ALH to study the accuracy and reliability of ALH data, since they were obtained with verified technologies which can be just as accurate, if not more so. Although the first studies were carried out solely in the water area through the comparison of the data gathered by ALH and MBES, it soon became clear that a higher number of clearly defined elements was necessary. Therefore, the land study was added to the data collected through ALS technology. The ALH technology has proven to be the best solution for obtaining coastline cartography, in addition to being the most efficient as well as the safest. Keywords: LIDAR (LIgh Detection And Ranging), ALB (Airborne LIDAR Batymetry), ALH (Airborne LIDAR Hidrographic), ALS(Airborne Laser Scaninning),MBES (Multi Beam Echosounders ), MDS (Digital Surface Model), MDT (Digital Terrain Model), TVU (Total Vertical Uncertainty), IHO (International Hydrographic Organization)