Comparison of remote sensing-based indices for ash vitality detection in North-East Germany

2020 ◽  
Author(s):  
Michael Förster ◽  
Anne Clasen ◽  
Kai Jütte ◽  
Veronika Döpper ◽  
Birgit Kleinschmit
Keyword(s):  
Remote Sensing ◽  
East Germany ◽  
Remote Sensing Data ◽  
North East ◽  
The North ◽  
Ash Trees ◽  
One Year ◽  
Regional Forest ◽  
Structural Indices ◽  
Higher Sensitivity

<p>The north-East of Europe is affected by the ash (Fraxinus excelsior) dieback caused by the fungal pathogen Hymenoscyphus pseudoalbidus. A great variety of studies utilize remote sensing data and subsequently derived spectral indices to estimate the magnitude and spatial distribution of the damage for different tree types. </p><p>Often, structural indices, such as the NDVI are applied to detect already affected tree (sometimes even for early detection). However, there are differences in the suitability of an index. While a structural index, might have advantages when the canopy is not closed, pigment-based indices can show more variation within a full crown coverage forest. Therefore, the season of data acquisition might define the preferred index-selection. The same accounts not just for seasonal but for inter-annual changes, too. Here, the pigment indices show a higher sensitivity towards changes due to damages than structural indices.</p><p>To show these differences, the presented study is evaluating a variety of indices derived by hyperspectral imagery for affected ash trees in north-east Germany. This includes images from different phenological stages within one year (2015) and a comparison between 2011, 2015, and 2019 because the decline increased severely within this timespan for the observed trees. The indices were compared with tree damage estimations from the regional forest administration. </p><p>Preliminary results show a better relation for structural indices in autumn, but higher relation for pigment-based indices in spring and summer, once the crown is closed. A higher sensitivity to changes between 2011 and 2019 can be shown for pigment-based indices.</p>

scholarly journals Geothermal potential mapping of Northeast Morocco (Bekrane-Ahfir) using remote sensing data and GIS

2021 ◽  
Vol 234 ◽  
pp. 00093
Author(s):  
Intissar El Morabit ◽  
Soufiane Maimouni ◽  
Ahmed Fekri
Keyword(s):  
Remote Sensing ◽  
Active Sites ◽  
Remote Sensing Data ◽  
Landsat 8 ◽  
North East ◽  
The North ◽  
Hydrothermal Springs ◽  
Geothermal Potential ◽  
Geothermal Activity ◽  
Potential Mapping

Geothermal energy is part of the renewable energy mix. It is used for heating, air conditioning and sometimes even for the production of electricity. Prospecting for such a resource proves to be a difficult and capital-intensive task. To overcome this constraint, we have used remote sensing which is an adequate tool to guide the prospecting through the elaboration of hydrothermal resource potential maps at the level of zones that present a favorable potential for exploitation (hyper-tectonized sites, volcanic sites, faulted sites, sites with hot geological formations, seismic zones...). The objective of this work is to carry out a study on the North-East of Morocco (Berkane Province), in order to identify favorable sites for geothermal exploitation such as geologically and hydrogeologically active sites. The methodology adopted consists in processing the images of the OLI (Operational Land Imager) and TIRS (Thermal Infrared Sensor) sensors of the Landsat-8 satellite in order to extract spectral indices (Clay mineral Index and Ferrous mineral Index,) detecting a geothermal activity and the surface temperature map (LST) using muticriteria analysis method (MCA). ) in the north-eastern part of Morocco. The results obtained show an almost perfect concordance of the distribution of the above-mentioned indices, with the map of lineaments which are considered as heat drains from the depth to the surface. Moreover, a correct correlation was established during the validation of these results with the map of the inventory of hydrothermal springs identified in the study area.

scholarly journals Perspectives of the development of complex interdisciplinary hydrological and geocryological research in the North-East of Russia

2021 ◽  
Vol 66 (1) ◽  
Author(s):  
Olga M. Makarieva ◽  
◽  
Nataliia V. Nesterova ◽  
Andrey A. Ostashov ◽  
Anastasia A. Zemlyanskova ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Remote Sensing ◽  
Water Balance ◽  
River Runoff ◽  
Remote Sensing Data ◽  
Field Research ◽  
River Basins ◽  
Soviet Period ◽  
North East ◽  
The North

Climate warming and anthropogenic impact causes transformation of geocryological conditions in the river basins of the North-East of Russia. Changes in the thickness of the active layer, configuration of taliks, types of landscapes and other factors lead to transformation of water exchange processes between surface and groundwater runoff. This is manifested in the seasonal redistribution of the components of the water balance, accelerated melting of aufeis, change in the ratio of waters of different genesis in the structure of river runoff. As a result, natural and anthropogenic risks that affect the safe and efficient development of infrastructure and socio-economic processes are increasing. At the same time the system of observations developed in the Soviet period has been practically destroyed in the region. This paper offers a vision of organizing complex multidisciplinary research to assess and project the changes in the conditions of underground and surface water interaction in natural and disturbed river basins of the cryolithozone of the North-East of Russia, including for solving applied problems, based on permafrost, hydrology, hydrogeology, landscape science and geophysics with applications of remote sensing and field research integrated through mathematical modeling methods. To achieve the goal, the identification of natural and disturbed landscapes using remote sensing data, and key areas for detailed research will be selected. Geophysical and drilling works will be carried out within the sites to establish permafrost-hydrogeological conditions, monitoring stations will be equipped to determine hydrogeological, hydrometeorological and geocryological characteristics, including sampling for isotopic and hydrogeochemical studies. As the main key sites, it is proposed to use the area of ​​the Kolyma water-balance station and the site on Anmangynda aufeis, for which there are long-term observation series in the 20th century. Field data will become the basis for improving the mathematical model of runoff formation, considering the relationship between groundwater and river runoff in the conditions of permafrost. Mathematical modeling will make it possible to quantitatively analyze the water balance of rivers considering various factors and project water availability both for specific industrial facilities and for the region as a whole.

scholarly journals Use of remote sensing data to study ice cover in the Dnipro Reservoirs

2020 ◽  
Vol 29 (1) ◽  
pp. 206-216
Author(s):  
Viktor I. Vyshnevskyi ◽  
Serhii A. Shevchuk
Keyword(s):  
Remote Sensing ◽  
Remote Sensing Data ◽  
Ice Cover ◽  
Typical Feature ◽  
Industrial Enterprises ◽  
North East ◽  
The North ◽  
South West ◽  
Ice Regime ◽  
The Impact

The information on the use of remote sensing data when studying the ice cover of the Dnipro Reservoirs is given. The main source of data was the images obtained by the satellites Sentinel-2, Landsat, Aqua and Terra. In addition, the observation data from the hydrological and meteorological stations were used. The combination of these data enabled to study the patterns of ice regime in the Dnipro Reservoirs, to specify some features that cannot be determined by regular monitoring. A typical feature of the ice cover of all reservoirs of the Dnipro Cascade, besides the Kyivske one, is the impact of hydropower plants (HPP) located upstream. The runoff of the rivers flowing into the Kyivske Reservoir significantly influences its ice cover. This is especially relates to the period of spring flood. Besides the Dnipro and the Pripyat Rivers, relatively small the Teteriv and the Irpin Rivers flowing from the south-west to the north-east have a rather significant effect on the ice cover of this reservoir. The distribution of ice cover in the Kanivske Reservoir, compared to the Kanivske one, is significantly less. In addition to more southern location and warmer climate, the city of Kyiv also influences the ice cover on it, namely due to the discharge of wastewater from several industrial enterprises, Kyivska TPP-5 and Bortnitska Station of Aeration are ones of them. The impact of Trypilska TPP, which located downstream, is also significant. The longest duration of ice cover in the Kanivske Reservoir is observed in its south-eastern part. A point of interest about the Kremenchuts’ke Reservoir is the fact that the ice cover in it remains for the longest period compared to the other reservoirs. The largest duration of ice cover in this reservoir is observed in the Sulska Bay. The typical feature of the Kamianske Reservoir is the accumulation of ice in its narrow parts. Within the Dniprovske Reservoir, the longest freezing period is observed in the Samara Bay. Besides the operation of hydropower station, the industrial enterprises of Kamianske town and Dnipro city have a great effect on the upper part of this reservoir. There are significant differences in the ice regime of the different parts of the Kakhovske Reservoir, which extends from the north-east to the south-west. The distribution of ice in its shallow north-eastern part is usually much larger than in narrower south-western part.

scholarly journals INDEKS KUALITAS LINGKUNGAN (IKL) DI WILAYAH PERAIRAN NATUNA TERKAIT DENGAN AKTIVITAS INDUSTRI MIGAS

2016 ◽  
Vol 12 (2) ◽  
pp. 93
Author(s):  
Rahayu Kusuma Risdianto ◽  
Undang Hernawan
Keyword(s):  
Remote Sensing ◽  
Water Quality ◽  
Environmental Quality ◽  
Quality Index ◽  
Remote Sensing Data ◽  
Analysis Data ◽  
Quality Parameters ◽  
North East ◽  
The North ◽  
Industry Area

Indeks Kualitas Lingkungan (IKL) dapat digunakan untuk memantau kondisi lingkungan. Analisis Indeks Kualitas Lingkungan (IKL) dilakukan di kawasan industri migas di perairan Laut Natuna. Studi ini menggunakan data penginderaan jauh dan analisa sembilan parameter kualitas air dari 15 titik lokasi untuk menyusun algoritma kualitas air. Hasil dari studi ini menunjukkan distribusi IKL tergolong kriteria baik (70-91) dan sangat baik (91-100). Nilai IKL baik berada di bagian Utara (U) sampai Timur Laut (TL) dan Timur (T) sampai Selatan (S) dan terlihat dominan di bagian Selatan (S) sampai Utara (U). Nilai IKL sedang berada di bagian Barat Daya (BD) sampai Barat (B). Distribusi IKL sangat baik dominan berada di bagian Utara (U) sampai Timur Laut (TL), Timur (T) sampai Selatan (S) dan terlihat dominan di bagian Timur Laut (TL) sampai Timur (T). Kata kunci: IKL, penginderaan jauh, MODIS, kualitas Air, perairan Natuna. Environmental Quality Index (EQI) can be used for monitoring of environmental condition. Analysis of Environmental Quality Index (EQI) in petroleum and gas industry area had been done at Natuna waters. This study was based on remote sensing data and analysis data of nine water quality parameters from fifteen sampling sites to arrange water quality algorithm. The result shows that the distribution of EQI is within good (70-91) to very good (91-100) criteria. The good value of EQI is distributed from north (N) to north east (NE) and east (E) until south (S) that is dominated at the soutern to northern parts. The medium value of EQI is in southwest to west parts. The very good EQI is dominated at the north (N) until North East (NE), East (E) to southern parts that is dominated at the northeast to eastern parts. Keywords: EQI, Remote Sensing, MODIS, Water Quality.

scholarly journals Statistical Characteristics of Cyclonic Warm-Core Eddies and Anticyclonic Cold-Core Eddies in the North Pacific Based on Remote Sensing Data

2019 ◽  
Vol 11 (2) ◽  
pp. 208 ◽  
Author(s):  
Wenjin Sun ◽  
Changming Dong ◽  
Wei Tan ◽  
Yijun He
Keyword(s):  
Remote Sensing ◽  
North Pacific ◽  
Kuroshio Extension ◽  
Remote Sensing Data ◽  
Statistical Characteristics ◽  
The North ◽  
Warm Core ◽  
Spatio Temporal ◽  
Cold Core ◽  
The North Pacific

A (an) cyclonic (anticyclonic) eddy is usually associated with a cold (warm) core caused by the eddy-induced divergence (convergence) motion. However, there are also some cyclonic (anticyclonic) eddies with warm (cold) cores in the North Pacific, named cyclonic warm-core eddies (CWEs) and anticyclonic cold-core eddies (ACEs) in this study, respectively. Their spatio-temporal characteristics and regional dependence are analyzed using the multi-satellite merged remote sensing datasets. The CWEs are mainly concentrated in the northwestern and southeastern North Pacific. However, besides these two areas, the ACEs are also concentrated in the northeastern Pacific. The annual mean number decreases year by year for both CWEs and ACEs, and the decreasing rate of the CWEs is about two times as large as that of the ACEs. Moreover, the CWEs and ACEs also exhibit a significant seasonal variation, which are intense in summer and weak in winter. Based on the statistics of dynamic characteristics in seven subregions, the Kuroshio Extension region could be considered as the most active area for the CWEs and ACEs. Two possible mechanisms for CW-ACEs generation are discussed by analyzing two cases.

scholarly journals Magnetic signatures of subsurface faults on the northern upper flank of Mt Etna (Italy)

2021 ◽  
Vol 64 (1) ◽  
Author(s):  
Rosalba Napoli ◽  
Gilda Currenti ◽  
Antonino Sicali
Keyword(s):  
Source Parameters ◽  
Magma Ascent ◽  
Magnetic Survey ◽  
Tectonic Structures ◽  
Near Surface ◽  
North East ◽  
The North ◽  
3D Euler Deconvolution ◽  
Mt Etna ◽  
Structural Indices

A ground magnetic study was performed on the northern upper flank of Mt. Etna to provide new insights into subsurface volcano-tectonic structures. The high resolution magnetic survey was focused on the main structures of Piano delle Concazze, a large flat area dominated by the North- East crater and bounded by the rim of the Valle del Leone depression and the extremity of the North- East Rift. More than 2,500 measurements were gathered with a sampling step of about 3 m covering an area of about 0.2 km2. The total-intensity anomaly field shows the presence of intense South- North aligned maxima related to shallow geological structures affecting this area. Filtering techniques and 2.5D modeling have been applied for the determination of the magnetic source parameters. In order to distinguish the near surface structure, filters of the vertical derivatives, Butterworth high-pass and the tilt derivative were used. The 3D Euler deconvolution has been applied to estimate the depth and the structural indices of the causative sources. The calculated structural indices, that express the geometrical nature of the source, are in agreement with forward modeling. They show that the area is mainly affected by subvertical normal fault and the estimated depth of magnetic sources ranges between 10 m and 40 m. Our total field magnetic survey shows that characteristic magnetic anomalies are related to fault zones in the Piano delle Concazze that are well consistent with the local tectonics. The subsurface structures that have been detected allowed to delineate the general structural framework of the area. In particular, it was possible to clarify that these structures seem to be not deep rooted and consequently they can hardly act as preferential pathways for magma ascent.

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