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Fury of nature: evaluating the impact of hailstorm on vegetation using sentinel 2 data at Moran, India

Neog Rituraj

Acta Geophysica

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2023

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Vol. 71, no. 6

3025--3039

EN

The primary objective of the study is to analyze the impact assessment of hailstorms on vegetation in the Moran region of Assam. The experiments employed sentinel-2A data of December, 2022 and January, 2023 for the computation of the NDVI, GNDVI, and MSAVI indices and their temporal dynamics. Further, LandScan gridded (1 k × 1 km) population data of 2021 have been used to portray the population affected in the study area. The result evidenced a significant decline in the mean NDVI (Normalized Difference Vegetation Index), GNDVI (Green Normalized Difference Vegetation Index), and MSAVI (Modified Soil Adjusted Vegetation Index) from the pre-hailstorm to the post-hailstorm period. The above indices declined from 0.270, 0279 and 0.416 in pre-hailstorm (24 December, 2022) period to 0.257, 0.269 and 0.410 in post-hailstorm period (3 January, 2023). Similarly, the area under healthy vegetation decreased from 72.06 and 103.55 sq km in 2022 to 60.74 and 96.35 sq km in 2023, based on GNDVI and MSAVI, respectively. The hailstorm affected the majority of villages as well as the population lying to the east of the NH-37, i.e., the Charaideo district of Assam. The Villages such Bagtali Sonowal, Demorukinar Changmai, Hatkhola gaon and Mout gaon experienced maximum damage to vegetation. Overall, 125.355 and 132.07 sq km of area considering both assessments (MSAVI & GNDVI with population) with a total population of about 131,342 are severely affected by hailstorm phenomena.

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Zestawy wyrobów do mocowania modułów fotowoltaicznych i kolektorów słonecznych w aspekcie wytrzymałości i bezpieczeństwa użytkowania

Frąckiewicz Piotr, Jakimowicz Marzena

Materiały Budowlane

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2021

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nr 7

41--44

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Pokrycie dachu z folii PVC zniszczone przez grad

Łodo A., Chodór M.

Materiały Budowlane

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2015

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nr 6

82--83

PL

W wyniku opadu gradu w trakcie majowej burzy w 2014 r. nastąpiła perforacja pokrycia z membrany PVC na dachu sześcioletniej hali przemysłowej oraz budynku socjalno-technicznego i administracyjnego. Zalanie hali po uszkodzeniu pokrycia było wynikiem błędnego zaprojektowania połączenia blach T55 z obudową ścian zewnętrznych i z płatwiami. Małe pochylenie połaci dachowej uniemożliwiło zmianę pokrycia z membrany PVC na blaszane.

EN

PVC roof membrane covering the six-year old industrial building, social and technical building as well as office building as a result of heavy spring hailstorm in May 2014 was perforated. Flooding industrial hall after damage of roofing resulted from incorrect design of connection between steel sheet T55 and purlin as well as external fittings. Small slope of roofing disabled change the PVC membrane on the new cover steel sheet.

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Very large hail occurrence in Poland from 2007 to 2015

Pilorz W.

Contemporary Trends in Geoscience

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2015

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Vol. 4, iss. 1

45--55

EN

Very large hail is known as a presence of a hailstone greater or equal to 5 cm in diameter. This phenomenon is rare but its significant consequences, not only to agriculture but also to automobiles, households and people outdoor makes it essential thing to examine. Hail appearance is strictly connected with storms frequency and its kind. The most hail-endangered kind of storm is supercell storm. Geographical distribution of hailstorms was compared with geographical distribution of storms in Poland. Similarities were found. The area of the largest number of storms is southeastern Poland. Analyzed European Severe Weather Database (ESWD) data showed that most of very large hail reports occurred in this part of Poland. The probable reason for this situation is the longest period of lasting tropical airmasses in southeastern Poland. Spatial distribution analysis shows also more hail incidents over Upper Silesia, Lesser Poland, Subcarpathia and Świętokrzyskie regions. The information source about hail occurrence was ESWD - open database, where everyone can add report and find reports which meet given search criteria. 69 hailstorms in the period of 2007 – 2015 were examined. They caused 121 very large hail reports. It was found that there is large disproportion in number of hailstorms and hail reports between individual years. Very large hail season in Poland begins in May and ends in September with cumulation in July. Most of hail occurs between 12:00 and 17:00 UTC, but there were some cases of very large (one extremely large) hail at night and early morning hours. However very large hail is a spectacular phenomenon, its local character determines potentially high information loss rate and it is the most significant problem in hail research.