Aquatic heterophylly as a survival strategy in Melaleuca quinquenervia (Myrtaceae)

The broad-leaf paper bark or melaleuca tree (Melaleuca quinquenervia (Cav.) Blake) is an emergent, semiaquatic tree whose morphological plasticity allows it to invade wetland and terrestrial habitats. While studying the effect of hydroperiod on melaleuca seedlings, two types of aquatic leaf forms were observed under submersed conditions. Linear leaves developed at least 9.5 cm below the water surface and were associated with short internodes. Short, broad, incurved transitional leaves formed as the seedlings approached the water surface. Aerial leaves were flat and spatulate to oblanceolate. Leaf length to width ratios, stomatal density, and shoot internode lengths were significantly different between the three leaf forms. Characteristics of submersed melaleuca seedlings are similar to those of other aquatic heterophyllic plants that grow in areas where water levels fluctuate. An increased understanding of morphological variations of this invasive tree may lead to additional control methods and mechanisms. Keywords: Melaleuca, aquatic, heterophylly.

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Distribution and Morphological Variations of Invasive Macrophytes Elodea Nuttallii (Planch.) H. St. John and Elodea Canadensis Michx in Croatia

Acta Botanica Croatica ◽

10.2478/botcro-2014-0011 ◽

2014 ◽

Vol 73 (2) ◽

pp. 437-446 ◽

Cited By ~ 3

Author(s):

Aleksandra Kočić ◽

Janja Horvatić ◽

Sven D. Jelaska

Keyword(s):

Morphological Variability ◽

Environmental Parameters ◽

Leaf Length ◽

Water Levels ◽

Internode Length ◽

Leaf Width ◽

Elodea Nuttallii ◽

Channel Network ◽

Morphological Variations ◽

Wide Range

Abstract The invasive species Elodea nuttallii was recorded for the first time in the Croatian flora in 2006, in the drainage channels of Kopački rit (Baranja). After its establishment, E. nuttallii begins to spread to the eastern and northern part of the drainage channel network from 2006-2009. High water levels are responsible for the linear spreading direction of E. nuttallii, E. nuttallii and E. canadensis show a wide range of morphological variation, which is characteristic of successful invaders. To show morphological variations of two Elodea species, the most important characters indicated in the literature were measured on 24 fresh collected samples from the seven sites in Croatia. In spite of some overlap in leaf length and width between the two Elodea species, the differences of all morphological traits except internode length are statistically significant. In E. nuttallii leaf width, length and internode length show a higher morphological variability as a result of the higher adaptive strategy to environmental parameters. The most reliable morphologi-cal characters distinguishing E. nuttallii and E. canadensis are leaf width 0.5 mm below the tip and the angle at the apex. E. nuttallii can be expected to spread to other areas of Croatia.

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Denoising of river surface photogrammetric DEMs using deep learning

10.5194/egusphere-egu21-10266 ◽

2021 ◽

Author(s):

Radosław Szostak ◽

Przemysław Wachniew ◽

Mirosław Zimnoch ◽

Paweł Ćwiąkała ◽

Edyta Puniach ◽

...

Keyword(s):

Higher Education ◽

Deep Learning ◽

Water Level ◽

Water Surface ◽

Research University ◽

Static Characteristic ◽

Water Levels ◽

Training Dataset ◽

Observation Data ◽

Characteristic Points

<p>Unmanned Aerial Vehicles (UAVs) can be an excellent tool for environmental measurements due to their ability to reach inaccessible places and fast data acquisition over large areas. In particular drones may have a potential application in hydrology, as they can be used to create photogrammetric digital elevation models (DEM) of the terrain allowing to obtain high resolution spatial distribution of water level in the river to be fed into hydrological models. Nevertheless, photogrammetric algorithms generate distortions on the DEM at the water bodies. This is due to light penetration below the water surface and the lack of static characteristic points on water surface that can be distinguished by the photogrammetric algorithm. The correction of these disturbances could be achieved by applying deep learning methods. For this purpose, it is necessary to build a training dataset containing DEMs before and after water surfaces denoising. A method has been developed to prepare such a dataset. It is divided into several stages. In the first step a photogrammetric surveys and geodetic water level measurements are performed. The second one includes generation of DEMs and orthomosaics using photogrammetric software. Finally in the last one the interpolation of the measured water levels is done to obtain a plane of the water surface and apply it to the DEMs to correct the distortion. The resulting dataset was used to train deep learning model based on convolutional neural networks. The proposed method has been validated on observation data representing part of Kocinka river catchment located in the central Poland.</p><p>This research has been partly supported by the Ministry of Science and Higher Education Project &#8220;Initiative for Excellence &#8211; Research University&#8221; and Ministry of Science and Higher Education subsidy, project no. 16.16.220.842-B02 / 16.16.150.545.</p>

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The geometric parameters of plants on the spur dykes in a selected section of the Odra River

E3S Web of Conferences ◽

10.1051/e3sconf/20184500110 ◽

2018 ◽

Vol 45 ◽

pp. 00110

Author(s):

Magda Hudak

Keyword(s):

Water Surface ◽

Flow Resistance ◽

Water Levels ◽

Flow Conditions ◽

Plant Structure ◽

Central Section ◽

Quantitative Characteristics ◽

Odra River ◽

The Impact ◽

Resistance Coefficients

Spur dykes are structures for regulating rivers. They are designed for medium water levels, when spur dyke tops are above the water surface. In the central section of the Odra River the water level is changeable, and the spur dykes work in different hydrological conditions: as non-submerged and submerged. Correct recognition of the plant structure growing on the spur dykes is of great importance in the context of the subsequent allocation of its measure related to the hydraulic action, among others coefficients of resistance of plant zones and refers mainly to grasses. In hydraulic calculations, it is required to determine the value of flow resistance coefficients. In such a departure, the flow is omitted in the area occupied by vegetation. Therefore, it is necessary to know the quantitative characteristics of overgrowth. Vegetation should be presented in the form of a model reflecting the impact of plants growing on the spur dykes and their impact on the water flow conditions in the river. Literature data are not very numerous and are still awake unsatisfied. The paper presents the results of research on the density of vegetation on the Odra River in the Nowa Sól region.

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Observing river stages using unmanned aerial vehicles

10.5194/hess-2016-49 ◽

2016 ◽

Author(s):

Tomasz Niedzielski ◽

Matylda Witek ◽

Waldemar Spallek

Keyword(s):

Unmanned Aerial Vehicles ◽

Water Surface ◽

Water Levels ◽

Hydrodynamic Models ◽

Surface Areas ◽

Aerial Vehicles ◽

Potential Applications ◽

Sw Poland ◽

High Flows ◽

Student’S T

Abstract. We elaborated a new method for observing water surface areas and river stages using unmanned aerial vehicles (UAVs). It is based on processing multitemporal m orthophotomaps produced from the UAV-taken visual-light photographs of n sites of the river, acquired with a sufficient overlap in each part. Water surface areas are calculated in the first place, and subsequently expressed as fractions of total areas of water-covered terrain at a given site of the river recorded on m dates. The logarithms of the fractions are later calculated, producing m samples of size n. In order to detect statistically significant increments of water surface areas between two orthophotomaps we apply the asymptotic and bootstrapped versions of the Student's t-test, preceded by other tests that aim to check model assumptions. The procedure is applied to five orthophotomaps covering nine sites of the Ścinawka river (SW Poland). The data have been acquired during the experimental campaign, at which flight settings were kept unchanged over nearly 3 years (2012–2014). We have found that it is possible to detect transitions between water surface areas produced by all characteristic water levels (low, mean, intermediate and high stages). In addition, we infer that the identified transitions hold for characteristic river stages as well. In the experiment we detected all increments of water level: (1) from low stages to: mean, intermediate and high stages; (2) from mean stages to: intermediate and high stages; (3) from intermediate stages to high stages. Potential applications of the elaborated method include verification of hydrodynamic models and the associated predictions of high flows using on-demand UAV flights performed in near real-time as well as monitoring water levels of rivers in ungauged basins.

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Morphological Variations of Robusta Coffee As a Response to Different Altitude in Lampung

Pelita Perkebunan (a Coffee and Cocoa Research Journal) ◽

10.22302/iccri.jur.pelitaperkebunan.v35i2.378 ◽

2019 ◽

Vol 35 (2) ◽

pp. 103-118

Author(s):

Erwin Prastowo ◽

Rina Arimarsetiowati

Keyword(s):

Environmental Conditions ◽

Morphological Characteristics ◽

Fruit Weight ◽

Leaf Length ◽

Qualitative Variable ◽

Morphological Variations ◽

Agronomic Practices ◽

Robusta Coffee ◽

Length Width ◽

Key Issues

The coffee growth is considered to depend, partly, on the environmental condition at which they develop to accomplish both vegetative and generative stages. An exploratory survey in Lampung aimed at investigating the morphological characteristics of 13 Robusta coffee accessions growing on different altitudes.Local superior coffee clones were selected from eight farms, and subjected to identifications. Three key issues were concerned for both quantitatively, i.e. plant components of leaves, branches, and fruits, and qualitatively such as leaves and fruit characteristics, i.e. colour and shape. The analysis shows a similarity of about 60% of total qualitative variable identified among different accessions. The remaining characters are suggested to be more varying such as flush colour, leaf surface, ripe fruit colour, and stipule shape. Furthermore, a quantitative analysis showed a higher level of similarity for fruit characters, i.e. fruit length, -width, and -thickness, and to a slightly lower level for leaf characteristics, i.e. leaf length and -width, and number of productive branches. It was revealed that some variables, i.e. fruit weight; leaf and seed; and canopy characteristics, explaining the morphological variation of coffee throughout the accessions. Furthermore, cluster analysis may indicated a possible similarity of coffee morphologies either from area with different or the same environmental conditions. A high heterogeneity related to environmental conditions, genotypic variations, plant nutritional status, and agronomic practices, which unable to confirm in the present study, may limit the specific conclusions.

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Response of wild mammals to seasonal shrinking-and-expansion of habitats due to flooding regime of the Pantanal, Brazil

Brazilian Journal of Biology ◽

10.1590/s1519-69842006000600006 ◽

2006 ◽

Vol 66 (4) ◽

pp. 991-998 ◽

Cited By ~ 16

Author(s):

S. B. Mamede ◽

C. J. R. Alho

Keyword(s):

Dry Season ◽

Water Levels ◽

Wild Mammals ◽

Flooding Regime ◽

Terrestrial Mammals ◽

Paraguay River ◽

Terrestrial Habitats ◽

Slow Moving ◽

Blastocerus Dichotomus ◽

Seasonally Flooded

The Pantanal is a large savanna wetland (138,183 km² in Brazil), important for its wildlife, fed by tributaries of the upper Paraguay River, center of South America (Brazil, touching Bolivia and Paraguay). Uplands are plateaus (250-1,200 m high, 215,000 km² in Brazil) and flatland is the Pantanal (80-150 m high, 147,574 km² in Brazil). Rivers are slow moving when they meet the flatland (slope 0.3-0.5 m/km east-west; 0.03-0.15 m/km north-south), periodically overflowing their banks, creating a complex seasonal habitat range. Recurrent shallow flooding occupies 80% of the Pantanal; during the dry season flooded areas dry up. Fluctuating water levels, nutrients and wildlife form a dynamic ecosystem. A flooding regime forms distinct sub-regions within the Pantanal. A mammal survey was carried out in the sub-region of the Rio Negro from April, 2003 through March, 2004 to study the diversity and abundance of terrestrial mammals during the dry and flooding seasons. A total of 36 species were observed in the field. The capybara Hydrochaeris hydrochaeris was the most frequent species, followed by the crab-eating-fox Cerdocyon thous and the marsh deer Blastocerus dichotomus. The highest abundance of species was observed during the dry season (August and September), when there is a considerable expansion of terrestrial habitats, mainly seasonally flooded grassland. Animal abundance (in terms of observed individual frequencies) varied during the dry and wet seasons and the seasonally flooded grassland was the most utilized habitat by mammals in the dry season.

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Study on Backwater Effect Due to Polavaram Dam Project under Different Return Periods

Water ◽

10.3390/w12020576 ◽

2020 ◽

Vol 12 (2) ◽

pp. 576 ◽

Cited By ~ 1

Author(s):

Amarnath C R ◽

Shashidhar Thatikonda

Keyword(s):

Unsteady Flow ◽

Water Surface ◽

Water Levels ◽

Surface Elevation ◽

Flood Frequency Analysis ◽

Discharge Data ◽

Gate Operation ◽

Water Surface Elevation ◽

Flow Simulations ◽

Flood Discharge

In this study, we present a scenario to evaluate the backwater impacts on upstream of the Polavaram dam during floods. For this purpose, annual peak discharges across the different gauge stations in river stretch considered for flood frequency analysis. Statistical analysis is carried out for discharge data to estimate probable flood discharge values for 1000 and 10,000 years return period along with 0.1 and 0.14 million m3/s discharge. Furthermore, the resulting flood discharge values are converted to water level forecasts using a steady and unsteady flow hydraulic model, such as HEC-RAS. The water surface elevation at Bhadrachalam river stations with and without dam was estimated for 1000 and 10,000 years discharge. Unsteady 2D flow simulations with and without the dam with full closure and partial closure modes of gate operation were analysed. The results showed that with half of the gates as open and all gates closed, water surface elevation of 62.34 m and 72.34 m was obtained at Bhadrachalam for 1000 and 10,000 years. The 2D unsteady flow simulations revealed that at improper gate operations, even with a flow of 0.1 million m3/s, water levels at Bhadrachalam town will be high enough to submerge built-up areas and nearby villages.

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Can GNSS-R Detect Abrupt Water Level Changes?

Remote Sensing ◽

10.3390/rs12213614 ◽

2020 ◽

Vol 12 (21) ◽

pp. 3614

Author(s):

Sajad Tabibi ◽

Olivier Francis

Keyword(s):

Water Level ◽

Vertical Velocity ◽

Energy Demand ◽

Water Surface ◽

Spatial Scales ◽

Satellite System ◽

Water Levels ◽

Level Gauge ◽

Surface Reflection ◽

Microwave Radar

Global navigation satellite system reflectometry (GNSS-R) uses signals of opportunity in a bi-static configuration of L-band microwave radar to retrieve environmental variables such as water level. The line-of-sight signal and its coherent surface reflection signal are not separate observables in geodetic GNSS-R. The temporally constructive and destructive oscillations in the recorded signal-to-noise ratio (SNR) observations can be used to retrieve water-surface levels at intermediate spatial scales that are proportional to the height of the GNSS antenna above the water surface. In this contribution, SNR observations are used to retrieve water levels at the Vianden Pumped Storage Plant (VPSP) in Luxembourg, where the water-surface level abruptly changes up to 17 m every 4-8 h to generate a peak current when the energy demand increases. The GNSS-R water level retrievals are corrected for the vertical velocity and acceleration of the water surface. The vertical velocity and acceleration corrections are important corrections that mitigate systematic errors in the estimated water level, especially for VPSP with such large water-surface changes. The root mean square error (RMSE) between the 10-min multi-GNSS water level time series and water level gauge records is 7.0 cm for a one-year period, with a 0.999 correlation coefficient. Our results demonstrate that GNSS-R can be used as a new complementary approach to study hurricanes or storm surges that cause abnormal rises of water levels.

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