scholarly journals Application of Remote Sensing in Natural Sciences

2021 ◽  
Author(s):  
Ehsan Atazadeh ◽  
Mostafa Mahdavifard
Keyword(s):  
Biological Sciences ◽  
Remote Sensing ◽  
Environmental Factors ◽  
Nutrient Status ◽  
Natural Sciences ◽  
Wide Area ◽  
Density Mapping ◽  
Status Assessment ◽  
Depth Sounding ◽  
Conservation And Management

Generally, the term biomass is used for all materials originating from photosynthesis. However, biomass can equally apply to animals. Conservation and management of biomass is very important. There are various ways and methods for biomass evaluation. One of these methods is remote sensing. Remote sensing provides information about biomass, but also about biodiversity and environmental factors estimation over a wide area. The great potential of remote sensing has received considerable attention over the last few decades in many different areas in biological sciences including nutrient status assessment, weed abundance, deforestation, glacial features in Arctic and Antarctic regions, depth sounding of coastal and ocean depths, and density mapping.

scholarly journals A Machine Learning Approach for Estimating the Trophic State of Urban Waters Based on Remote Sensing and Environmental Factors

2021 ◽  
Vol 13 (13) ◽  
pp. 2498
Author(s):  
Shijie Zhu ◽  
Jingqiao Mao
Keyword(s):  
Remote Sensing ◽  
Environmental Factors ◽  
Water Temperature ◽  
Trophic State ◽  
Trophic Levels ◽  
Water Bodies ◽  
Trophic State Index ◽  
Urban Water ◽  
Estimation Model ◽  
Input Variables

To improve the accuracy of remotely sensed estimates of the trophic state index (TSI) of inland urban water bodies, key environmental factors (water temperature and wind field) were considered during the modelling process. Such environmental factors can be easily measured and display a strong correlation with TSI. Then, a backpropagation neural network (BP-NN) was applied to develop the TSI estimation model using remote sensing and environmental factors. The model was trained and validated using the TSI quantified by five water trophic indicators obtained for the period between 2018 and 2019, and then we selected the most appropriate combination of input variables according to the performance of the BP-NN. Our results demonstrate that the optimal performance can be obtained by combining the water temperature and single-band reflection values of Sentinel-2 satellite imagery as input variables (R2 = 0.922, RMSE = 3.256, MAPE = 2.494%, and classification accuracy rate = 86.364%). Finally, the spatial and temporal distribution of the aquatic trophic state over four months with different trophic levels was mapped in Gongqingcheng City using the TSI estimation model. In general, the predictive maps based on our proposed model show significant seasonal changes and spatial characteristics in the water trophic state, indicating the possibility of performing cost-effective, RS-based TSI estimation studies on complex urban water bodies elsewhere.

scholarly journals History and impact of a bean (Phaseolus spp., Leguminosae, Phaseoleae) collection

2021 ◽  
Vol 2 (4) ◽  
pp. 21-43
Author(s):  
Daniel Debouck ◽  
Marcela Santaella ◽  
Luis Guillermo Santos
Keyword(s):  
Biological Sciences ◽  
Agricultural Development ◽  
Tropical Agriculture ◽  
Pests And Diseases ◽  
Low Phosphorus ◽  
Iron And Zinc ◽  
Per Se ◽  
Resources Conservation ◽  
The Impact ◽  
Conservation And Management

This work explains the reasons why a bean collection was established in 1973 at the International Center of Tropical Agriculture (CIAT) near Palmira in Colombia. It shows the impact of the collection on plant breeding and in agricultural development through the distribution of germplasm to the center’s bean breeding program, to successively find resistances to pests and diseases, adaptation to low phosphorus and drought, and more recently higher content of iron and zinc in seeds. The collection was also used to progress knowledge in biological sciences, as shown by a dozen of examples. A reason behind these successes was foresight and focus on diversity per se in the collection. The paper ends with a number of suggestions for the way ahead for the genetic resources conservation and management of these bean crops, and possible take-home lessons for curators in charge of other similar collections.

Remote Sensing Techniques and Its Application in Arid Zones of India

2017 ◽  
pp. 193-211
Author(s):  
Lokesh Kumar Jain
Keyword(s):  
Remote Sensing ◽  
Water Status ◽  
Leaf Age ◽  
Nutrient Status ◽  
Arid Zones ◽  
Large Area ◽  
Leaf Reflectance ◽  
Agronomic Management ◽  
Crop Type ◽  
Remote Sensing Techniques

Remote sensing technologies offer the potential for contributing the security to human existence on arid zones in the country in variety of ways. Remote Sensing in agriculture particularly for natural resource management. It provides important coverage, mapping and classification of land cover features. The remote view of the sensor and the ability to store, analyze, and display the sensed data on field maps are make remote sensing a potentially important tool for agriculture. The aerial photography gives two main advantages viz., speedy survey in very large area or remote area and precise description and recording of resources status. Remotely sensed images provide a means to assess field conditions and gave valuable insights into agronomic management. It led to understanding of leaf reflectance and leaf emittance changes in response to leaf thickness, species, canopy shape, leaf age, nutrient status, and water status. Understanding of leaf reflectance has led to quantify various agronomic parameters, e.g., leaf area, crop cover, biomass, crop type, nutrient status, and yield.

scholarly journals Hukum Minimum Liebig - Sebuah Ulasan dan Aplikasi Dalam Biologi Kontemporer

2018 ◽  
Vol 18 (1) ◽  
pp. 28 ◽  
Author(s):  
Wendy Achmmad Mustaqim
Keyword(s):  
Biological Sciences ◽  
Climate Change ◽  
Environmental Factors ◽  
Plant Growth ◽  
Ecological Factors ◽  
Short Review ◽  
Ecological Indicator ◽  
Half Century

Optimum plant growth depends on numerous ecological factors. In relation to this theme, there is an old law called Law of the Minimum Liebig. The postulate discussed the growth of the plant that is determined by the scarcest environmental factors. It is one of the oldest ecological postulate proposed more than one and a half-century ago. It has become one of the most important foundations for agriculture and biology, even the in contemporary biology. This short review will provide the history, principles, development and criticism, and applications in some recent biological sciences, including evolution, conservation, ecological indicator and even climate change.

scholarly journals An Approach to Minimize Atmospheric Correction Error and Improve Physics-Based Satellite-Derived Bathymetry in a Coastal Environment

2020 ◽  
Vol 12 (17) ◽  
pp. 2752
Author(s):  
Christopher O. Ilori ◽  
Anders Knudby
Keyword(s):  
Remote Sensing ◽  
Environmental Factors ◽  
Complete Solution ◽  
Atmospheric Correction ◽  
Florida Keys ◽  
Radiative Transfer Model ◽  
Inversion Method ◽  
Transfer Model ◽  
Landsat 8 ◽  
Depth Range

Physics-based radiative transfer model (RTM) inversion methods have been developed and implemented for satellite-derived bathymetry (SDB); however, precise atmospheric correction (AC) is required for robust bathymetry retrieval. In a previous study, we revealed that biases from AC may be related to imaging and environmental factors that are not considered sufficiently in all AC algorithms. Thus, the main aim of this study is to demonstrate how AC biases related to environmental factors can be minimized to improve SDB results. To achieve this, we first tested a physics-based inversion method to estimate bathymetry for a nearshore area in the Florida Keys, USA. Using a freely available water-based AC algorithm (ACOLITE), we used Landsat 8 (L8) images to derive per-pixel remote sensing reflectances, from which bathymetry was subsequently estimated. Then, we quantified known biases in the AC using a linear regression that estimated bias as a function of imaging and environmental factors and applied a correction to produce a new set of remote sensing reflectances. This correction improved bathymetry estimates for eight of the nine scenes we tested, with the resulting changes in bathymetry RMSE ranging from +0.09 m (worse) to −0.48 m (better) for a 1 to 25 m depth range, and from +0.07 m (worse) to −0.46 m (better) for an approximately 1 to 16 m depth range. In addition, we showed that an ensemble approach based on multiple images, with acquisitions ranging from optimal to sub-optimal conditions, can be used to estimate bathymetry with a result that is similar to what can be obtained from the best individual scene. This approach can reduce time spent on the pre-screening and filtering of scenes. The correction method implemented in this study is not a complete solution to the challenge of AC for satellite-derived bathymetry, but it can eliminate the effects of biases inherent to individual AC algorithms and thus improve bathymetry retrieval. It may also be beneficial for use with other AC algorithms and for the estimation of seafloor habitat and water quality products, although further validation in different nearshore waters is required.

scholarly journals 16-22: Quantification of the ablation zone after wide area circumferential pulmonary vein isolation applying a new high-density mapping system

EP Europace ◽  
2016 ◽  
Vol 18 (suppl_1) ◽  
pp. i6-i6
Author(s):  
Francesco Santoro ◽  
Ardan Saguner ◽  
Christine Lemes ◽  
Christian Sohns ◽  
Shibu Mathew ◽  
...  
Keyword(s):  
Pulmonary Vein ◽  
Pulmonary Vein Isolation ◽  
High Density ◽  
Wide Area ◽  
Ablation Zone ◽  
Density Mapping ◽  
Mapping System ◽  
Circumferential Pulmonary Vein Isolation

scholarly journals The Effect of Attenuation from Fish Shoals on Long-Range, Wide-Area Acoustic Sensing in the Ocean

2019 ◽  
Vol 11 (21) ◽  
pp. 2464 ◽  
Author(s):  
Daniel Duane ◽  
Byunggu Cho ◽  
Ankita D. Jain ◽  
Olav Rune Godø ◽  
Nicholas C. Makris
Keyword(s):  
Remote Sensing ◽  
Long Range ◽  
Cross Sections ◽  
Electromagnetic Waves ◽  
Low Frequency ◽  
Wide Area ◽  
Line Transect ◽  
Acoustic Sensing ◽  
Underwater Acoustic ◽  
Primary Means

Acoustics is the primary means of long-range and wide-area sensing in the ocean due to the severe attenuation of electromagnetic waves in seawater. While it is known that densely packed fish groups can attenuate acoustic signals during long-range propagation in an ocean waveguide, previous experimental demonstrations have been restricted to single line transect measurements of either transmission or backscatter and have not directly investigated wide-area sensing and communication issues. Here we experimentally show with wide-area sensing over 360° in the horizontal and ranges spanning many tens of kilometers that a single large fish shoal can significantly occlude acoustic sensing over entire sectors spanning more than 30° with corresponding decreases in detection ranges by roughly an order of magnitude. Such blockages can comprise significant impediments to underwater acoustic remote sensing and surveillance of underwater vehicles, marine life and geophysical phenomena as well as underwater communication. This makes it important to understand the relevant mechanisms and accurately predict attenuation from fish in long-range underwater acoustic sensing and communication. To do so, we apply an analytical theory derived from first principles for acoustic propagation and scattering through inhomogeneities in an ocean waveguide to model propagation through fish shoals. In previous experiments, either the attenuation from fish in the shoal or the scattering cross sections of fish in the shoal were measured but not both, making it impossible to directly confirm a theoretical prediction on attenuation through the shoal. Here, both measurements have been made and they experimentally confirm the waveguide theory presented. We find experimentally and theoretically that attenuation can be significant when the sensing frequency is near the resonance frequency of the shoaling fish. Negligible attenuation was observed in previous low-frequency ocean acoustic waveguide remote sensing (OAWRS) experiments because the sensing frequency was sufficiently far from the swimbladder resonance peak of the shoaling fish or the packing densities of the fish shoals were not sufficiently high. We show that common heuristic approaches that employ free space scattering assumptions for attenuation from fish groups can lead to significant errors for applications involving long-range waveguide propagation and scattering.

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