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Wyszukujesz frazę "spectral indices" wg kryterium: Temat


Wyświetlanie 1-5 z 5
Tytuł:
Features of Creating a System of Space Monitoring of Water-Supplied Territories for Irrigation in the South of Kazakhstan
Autorzy:
Malakhov, Dmitry V.
Tskhay, Mikhail
Kalashnikov, Alexander A.
Bekmukhamedov, Nurlan E.
Kalashnikov, Pavel A.
Baizakova, Aigul
Powiązania:
https://bibliotekanauki.pl/articles/2202277.pdf
Data publikacji:
2022
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
irrigation
spectral indices
decision tree
monitoring
evaluation
Opis:
The location of a significant part of the agricultural territories of Kazakhstan in the risk agriculture zone implies the development and further application of an objective monitoring system for irrigated territories. The purpose of the study was to develop methods for on-the-spot and long-term recognition of irrigated massifs and verification of methods in the conditions of the territories of southern Kazakhstan. The paper describes the methods of on-the-spot recognition of irrigated fields, the general assessment of irrigated areas for the growing season, as well as the method of recognizing promising areas for irrigation. The on-the-spot recognition of the fields is based on the use of such spectral indices as the Global Vegetation Moisture Index, Green Normalized Difference Vegetation Index, Normalized Difference Vegetation Index, and the xanthophyll index, combined into a single system by the Decision Tree algorithm. The assessment of irrigated areas is based on differences in the physiological state of plants in conditions of normal water supply and plants experiencing a lack of moisture. The evaluation system includes the calculation of the temperature difference according to the corresponding satellite data and the calculation of the difference in vegetation indices for the same period. The difference in vegetation indices in irrigated fields has positive values due to a steady increase in green biomass, and the temperature difference, on the contrary, is negative or zero, since healthy plants, with normal water supply, actively evaporate moisture to maintain optimal temperatures of biochemical processes. To develop these methods, ground data from 2017–2021 were used. Verification of the methods with ground data demonstrated acceptable accuracy (87% in the on-the-spot assessment of irrigated fields; 60–90% in the general assessment of irrigated areas), while the methods have significant potential for further improvement.
Źródło:
Journal of Ecological Engineering; 2022, 23, 11; 202--216
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Desertification detected in the Udhaim River Basin, Iraq. Based on Spectral Indices Derived from Remote Sensing Images
Autorzy:
Mail, Abd Al Salam Mohammed
Powiązania:
https://bibliotekanauki.pl/articles/2108226.pdf
Data publikacji:
2017-10-04
Wydawca:
Uniwersytet Warszawski. Wydział Geografii i Studiów Regionalnych
Tematy:
Desertification
GIS
remote sensing
spectral indices
Iraq
Opis:
In this study, changes in Land Use Land Cover (LULC) have been investigated over the Udhaim River Basin in Iraq by using spectral indices. NDVI, NDBI, NDWI, NDBaI, and CI represent respectively the vegetation, built-up, water bodies, bare-land, and soil crust of LULC. Two different images were acquired for the analysis, namely a Landsat 5 TM image from 1 July 2007 and a Landsat 8 OLI from 5 June 2015, both representing summer conditions. Results show that the percentages of vegetated land and water body areas have decreased. On the contrary, the percentages of built-up, bare land and soil crust areas have increased. The loss of vegetated areas and water body areas is a signal of land degradation leading to desertification, due to the combined effects of climate conditions, water deficit and human activities. Field observation shows that human activities have a significant impact on land degradation.
Źródło:
Miscellanea Geographica. Regional Studies on Development; 2017, 21, 3; 124-131
0867-6046
2084-6118
Pojawia się w:
Miscellanea Geographica. Regional Studies on Development
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Application of Remote Sensing Techniques and Spectral Analyzes to Assess the Content of Heavy Metals in Soil – A Case Study of Barania Góra Reserve, Poland
Autorzy:
Sobura, Szymon
Widłak, Małgorzata
Hejmanowska, Beata
Muszyńska, Joanna
Powiązania:
https://bibliotekanauki.pl/articles/2174645.pdf
Data publikacji:
2022
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
remote sensing
heavy metals
Sentinel-2
soil
spectral indices
Opis:
The understanding of the spatial and temporal dynamics of farmland processes is essential to ensure the proper crop monitoring and early decision making needed to support efficient resource management in agriculture. By creating appropriate crop management strategies, one can increase harvest efficiency while reducing costs, waste, chemical spraying, and inhibiting the impact of biotic and abiotic factors on crop stress. Only reliable spatial information makes it possible to comprehend the influence of various factors on the environment. The main objective of the research presented in the paper was to assess the possibility of using maps of vegetation and soil indices, such as NDVI, SAVI, IRECI, CIred-edge, PSRI and HMSSI, calculated on the basis of images from the Sentinel-2 satellite, to qualitatively determine the increased amount of heavy metals in the soil in the areas of small agricultural plots around the Barania Góra nature reserve in Poland. The conducted pilot project shows that the spectral indices: NDVI, SAVI, IRECI, CIred-edge, PSRI, and HMSSI, calculated on the basis of images from Sentinel-2, have the potential to assess the content of nickel zinc, chromium and cobalt in the soil on agricultural plots. However, the confirmation of the obtained results requires continuation of the research.
Źródło:
Geomatics and Environmental Engineering; 2022, 16, 4; 187--213
1898-1135
Pojawia się w:
Geomatics and Environmental Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
High accuracy Land Use Land Cover (LULC) maps for detecting agricultural drought effects in rainfed agro-ecosystems in central Mexico
Dokładne mapy użytkowania i pokrycia terenu (LULC) w śledzeniu suszy rolniczej w zasilanych opadowo agro-ekosystemach środkowego Meksyku
Autorzy:
Sierra-Soler, A.
Adamowski, J.
Qi, Z.
Saadat, H.
Pingale, S.
Powiązania:
https://bibliotekanauki.pl/articles/292428.pdf
Data publikacji:
2015
Wydawca:
Instytut Technologiczno-Przyrodniczy
Tematy:
drought
LULC maps
remote sensing
spectral indices
mapy LULC
susza
teledetekcja
wskaźniki spektralne
Opis:
Satellite remote sensing provides a synoptic view of the land and a spatial context for measuring drought impacts, which have proved to be a valuable source of spatially continuous data with improved information for monitoring vegetation dynamics. Many studies have focused on detecting drought effects over large areas, given the wide availability of low-resolution images. In this study, however, the objective was to focus on a smaller area (1085 km2) using Landsat ETM+ images (multispectral resolution of 30 m and 15 m panchromatic), and to process very accurate Land Use Land Cover (LULC) classification to determine with great precision the effects of drought in specific classes. The study area was the Tortugas-Tepezata sub watershed (Moctezuma River), located in the state of Hidalgo in central Mexico. The LULC classification was processed using a new method based on available ancillary information plus analysis of three single date satellite images. The newly developed LULC methodology developed produced overall accuracies ranging from 87.88% to 92.42%. Spectral indices for vegetation and soil/vegetation moisture were used to detect anomalies in vegetation development caused by drought; furthermore, the area of water bodies was measured and compared to detect changes in water availability for irrigated crops. The proposed methodology has the potential to be used as a tool to identify, in detail, the effects of drought in rainfed agricultural lands in developing regions, and it can also be used as a mechanism to prevent and provide relief in the event of droughts.
Teledetekcja zapewnia synoptyczny ogląd Ziemi i kontekst przestrzenny do pomiarów efektów susz, co okazało się cennym źródłem ciągłych danych dla monitorowania dynamiki roślinności. Wiele badań koncentrowało się na śledzeniu skutków suszy na rozległych obszarach ze względu na łatwą dostępność obrazów o małej rozdzielczości. Celem przedstawionej pracy była jednak analiza mniejszego obszaru (1085 km2) z użyciem zdjęć Landsat ETM+ (wielospektralna rozdzielczość 30 m, panchromatyczna – 15 m) oraz przeprowadzenie dokładnej klasyfikacji użytkowania i pokrycia powierzchni terenu (ang. Land Use Land Cover – LULC) z zamiarem określenia z dużą dokładnością skutków suszy w poszczególnych klasach. Terenem badań była Tortugas-Tepezata zlewnia II rzędu rzeki Moctezuma, zlokalizowana w stanie Hidalgo w środkowym Meksyku. Klasyfikację LULC przeprowadzono z użyciem nowej metody bazującej na dostępnych dodatkowych informacjach i analizie trzech zdjęć satelitarnych wykonanych w różnym czasie. Opracowana na nowo metodyka LULC zapewniła dokładność w granicach od 87,88 do 92,42%. Spektralne wskaźniki dla roślinności i wilgotności gleby oraz roślin wykorzystano do wykrycia anomalii w rozwoju roślinności spowodowanych suszą. Ponadto zmierzono i porównano powierzchnię zbiorników wodnych w celu sprawdzenia zmian w dostępności wody do nawadniania upraw. Proponowana metodyka może służyć jako narzędzie szczegółowej identyfikacji skutków suszy w zasilanych opadowo obszarach rolniczych oraz jako mechanizm zapobiegania i łagodzenia skutków suszy.
Źródło:
Journal of Water and Land Development; 2015, 26; 19-35
1429-7426
2083-4535
Pojawia się w:
Journal of Water and Land Development
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Use of Spatial Remote Sensing to Study the Temporal Evolution of the Water Retention of Al Massira Dam in Morocco
Autorzy:
Bounif, Mohammed
Rahimi, Abdelmejid
Boutafoust, Rachid
El Mjiri, Ikram
Powiązania:
https://bibliotekanauki.pl/articles/2202368.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
spatial remote sensing
Al Massira dam reservoir
spectral indices
Landsat
satellite image
Doukkala
irrigated perimeter
Opis:
In Morocco, irrigated agriculture is still very much linked to the climate and the water retention of dams. With climate change, this country is experiencing recurrent drought, which has led to deficits in water inflow from the rivers to the various dams. The Al Massira dam, the area of study, does not escape this trend. This dam is the only surface water source for the irrigated area of Doukkala. Therefore, special attention must be paid to monitoring this resource at this dam. Thus, the proposed study examined the possibilities offered by spatial remote sensing to improve the current information system. It aims to evaluate this dam’s reservoir by exploiting the data generated by using satellite images. The Landsat satellite images were used to assess the area of this dam by adopting an approach combining spectral indices with thresholding. Then, the existing relationship between the area of the dam lake were examined, determined by spatial remote sensing and its water retention measured in situ. The results obtained revealed a strong correlation between the two parameters. Therefore, a study was conducted to find the best model for predicting the dam’s impoundment based on its lake. The second-degree polynomial model showed a better performance. Given the results obtained, it is recommended to use geospatial methods in the current and prospective monitoring and steering system of water resources.
Źródło:
Journal of Ecological Engineering; 2023, 24, 2; 340--349
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-5 z 5

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