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Wyświetlanie 1-4 z 4
Tytuł:
Use of high spatial resolution satellite data for monitoring and characterization of drought conditions in the Northwestern Algeria
Autorzy:
Abbes, M.
Hammed, A.
Lafrid, A.
Mahi, H.
Nehal, L.
Powiązania:
https://bibliotekanauki.pl/articles/89204.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Wydział Geoinżynierii, Górnictwa i Geologii. Instytut Górnictwa
Tematy:
drought
Northwestern Algeria
SPI
NDVI
linear regression
satellite imagery
Opis:
Over the last decades, Algeria has witnessed intense and persistent drought periods characterized by a significant rainfall deficit. The Northwestern Algeria, such as the most south Mediterranean regions, is marked by alternating wet and dry periods and mixing between Atlantic and Mediterranean airs. In a climate context increasingly disturbed by anthropogenic activities, it is essential to analyze the dry episodes at spatial and temporal scales. In order to understand this problem, this work aims to use the potential of Landsat satellite imagery for monitoring drought conditions in the Cheliff watershed in the northwestern Algeria. As known, the behavior of vegetation is strongly related to climate changes. On this basis, a comparison of the variations in the standardized normalized difference vegetation index (NDVI) and those of the drought indices calculated from meteorological data was implemented. In fact, the rainfall series from fifty meteorological stations were analyzed. The standardized precipitation index (SPI) was calculated for the years 1987, 2000, 2006, 2011 and 2015, corresponding to the acquisition dates of Landsat images. Similarly, an extraction of the NDVI values was performed for each meteorological station. The linear regression between SPI and NDVI showed a good correlation. Thus, the obtained results enabled establishing a new drought index based essentially on satellite data. This index represents the advantage for monitoring spatially the drought phenomena and can solve the problem of climatic data lack.
Źródło:
Mining Science; 2018, 25; 71-99
2300-9586
2353-5423
Pojawia się w:
Mining Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spatial and Temporal Variability of Moisture Condition in Soil-Plant Environment using Spectral Data and Gis Tools
Autorzy:
Grzywna, H.
Dąbek, P. B.
Olszewska, B.
Powiązania:
https://bibliotekanauki.pl/articles/123280.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
drought
soil moisture
NDVI
Sentinel-2
satellite data
remote sensing
Opis:
The studies on agricultural droughts require long-term atmospheric, hydrological and meteorological data. On the other hand, today, the possibilities of using spectral data in environmental studies are indicated. The development of remote sensing techniques, increasing the spectral and spatial resolution of data allows using remote sensing data in the study of water content in the environment. The paper presents the results of the analysis of moisture content of soil-plant environment in the lowland areas of river valley using the spectral data from Sentinel-2. The analyses were conducted between February and November 2016. The spectral data were used to calculate the Normalize Differential Vegetation Index (NDVI) which provided the information about the moisture content of the soil-plant environment. The analyses were performed only on grasslands, on 22 objects located in the research area in the Oder river valley between Malczyce and Brzeg Dolny, Poland. The NDVI values were correlated with the hydrological and meteorological parameters. The analyses showed spatial and temporal variability of the moisture conditions in the soil-plant environment showed by the NDVI variability and existence some relationships between the climatic and spectral indices characterizing the moisture content in the environment.
Źródło:
Journal of Ecological Engineering; 2018, 19, 6; 56-64
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelling causality between agricultural and meteorological drought indices in the Corong River basin, East Java Indonesia
Autorzy:
Affandy, Nur A.
Iranata, Data
Anwar, Nadjadji
Maulana, Mahendra A.
Prastyo, Dedy D.
Jaelani, Lalu M.
Suryadi, F. X.
Powiązania:
https://bibliotekanauki.pl/articles/28411634.pdf
Data publikacji:
2023
Wydawca:
Instytut Technologiczno-Przyrodniczy
Tematy:
drought
river basin
standard normalisation difference vegetation index
NDVI
standardised precipitation evapotranspiration index
SPEI
time series regression
Opis:
The Lamongan Regency is an area in East Java, Indonesia, which often experiences drought, especially in the south. The Corong River basin is located in the southern part of Lamongan, which supplies the irrigation area of the Gondang Reservoir. Drought monitoring in the Corong River basin is very important to ensure the sustainability of the agricultural regions. This study aims to analyse the causal relationship between meteorological and agricultural drought indices represented by standardised precipitation evapotranspiration index (SPEI) and standard normalisation difference vegetation index (NDVI), using time series regression. The correlation between NDVI and SPEI lag 4 has the largest correlation test results between NDVI and SPEI lag, which is 0.41. This suggests that the previous four months of meteorological drought impacted the current agricultural drought. A time series regression model strengthens the results, which show a causal relationship between NDVI and SPEI lag. According to the NDVI-SPEI-1 lag 4 time series model, NDVI was influenced by NDVI in the previous 12 periods, and SPEI-1 in the last four periods had a determinant coefficient value of 0.4. This shows that the causal model between SPEI-1 and NDVI shows a fairly strong relationship for drought management in agricultural areas (irrigated areas) and is considered a reliable and effective tool in determining the severity and duration of drought in the study area.
Źródło:
Journal of Water and Land Development; 2023, 58; 178--188
1429-7426
2083-4535
Pojawia się w:
Journal of Water and Land Development
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ susz na wskaźniki teledetekcyjne grądu wysokiego i boru mieszanego w Lesie Młochowskim - analiza zobrazowań satelitarnych Sentinel-2 lasów objętych ochroną ścisłą oraz gospodarczych w latach 2017-2021
The influence of drought on remote sensing indicators of hornbeam and mixed coniferous forest in the Mlochowski Forest - analysis of Sentinel-2 satellite images of protected and economic forests in 2017-2021
Autorzy:
Kotlarz, J.
Powiązania:
https://bibliotekanauki.pl/articles/2136480.pdf
Data publikacji:
2021
Wydawca:
Instytut Badawczy Leśnictwa
Tematy:
susza
grad wysoki
bor mieszany
teledetekcja
Znormalizowany Wskaznik Wegetacji
znormalizowany roznicowy wskaznik wody
wskaznik NDWI zob.znormalizowany roznicowy wskaznik wody
wskaznik wilgotnosci MSI
satelita Sentinel-2
drought
NDVI
NDWI
MSI
Sentinel-2
oak-hornbeam forest
mixed coniferous forest
Opis:
The purpose of this paper was to describe processes that took place in the Łowicz-Błonia plain during the long-term drought of 2018 and the series of short-term droughts in 2019. For our analysis we used multispectral satellite images of high- ground hornbeam and mixed coniferous forest in the Młochowski Forest from 2017–2021. Sentinel-2 images provided the means to investigate the impact of mild droughts on the values of the NDVI (Normalized Difference Vegetation Index), NDWI (Normalized Difference Water Index), and MSI (Moisture Stress Index) as well as their monthly variability and differences between forest divisions. During periods without drought, the variability of all three indices was typical for each phase of the vegetation cycle: in the spring months the value of NDVI and MSI increased, NDWI decreased. During the autumn months, the behavior of the indicators reversed. In the period of long-term drought in 2018, the NDWI was higher in forest divisions with aspecies composition characteristic of a mixed coniferous forest compared to divisions with a higher share of deciduous trees such as oaks and hornbeams, including the rigorously protected area of high–hornbeam forest. NDWI was the only index to show a downward trend during mild droughts, while during moderate droughts, also a decrease in NDVI and MSI was observed. This was most clearly seen in deciduous forests. We did not observed any correlation of NDVI, NDWI, or MSI with the protection status of the forest or the absence thereof
Źródło:
Leśne Prace Badawcze; 2021, 82, 3; 87-100
1732-9442
2082-8926
Pojawia się w:
Leśne Prace Badawcze
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-4 z 4

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