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1

Bridge headwater afflux estimation using bootstrap resampling method

Kiraga Marta, Bajkowski Sławomir, Urbański Janusz

Archives of Civil Engineering

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2023

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Vol. 69, nr 1

21--37

EN

The bridge structure’s development causes a riverbed cross-sections contraction. This influences the flow regime, being visible during catastrophic floods. Then the flow velocity increases and water piles up upstream the bridge, where headwater afflux could be observed. These changes depend on the watercourse geometry and the bridge cross-section properties, especially on the degree of flow contraction under the bridge. Hydraulic conditions under the bridge depend on flow velocity, dimensions, and shape of abutments, the granulometric composition of bedload, which can be quantitatively characterized by hydraulic resistance coefficients. The research subject of headwater afflux is equated with the recognition of morphodynamic processes occurring along the passage route. The headwater afflux could be estimated by empirical formulas and by the energy method using Bernoulli’s law. Empirical methods are optimized by adopting various statistical criteria. This paper compares the headwater afflux values calculated using two existing empirical formulas, Rehbock and Yarnell, and compares them with the results of laboratory tests. Following the assumption that the free water surface is influenced by flow resistance, an attempt was made to include friction velocity in the empirical formulas. Based on the Authors’ database, the coefficients used were optimized using bootstrap resampling in Monte Carlo simulation. The analyses demonstrated that the formula best describing the phenomenon of headwater afflux upstream the bridge is an empirical formula built based on the historical Yarnell formula, which includes friction velocity value. The optimized equation provides an average relative error of 12.9% in relation to laboratory observations.

PL

Zabudowanie koryta rzeki filarami i przyczółkami mostu powoduje zwężenie jego przekroju. Wpływa to zmiany warunków przepływu, które widoczne są przede wszystkim podczas wezbrań katastrofalnych. Następuje wtedy zwiększenie prędkości przepływu oraz spiętrzenie wody przed mostem. Zmiany te zależą od geometrii koryta cieku oraz przekroju mostowego, a szczególnie stopnia zwężenia strumienia pod mostem. Warunki hydrauliczne pod mostem zależą od prędkości przepływu, wymiarów i kształtu podpór, składu granulometrycznego rumowiska, które scharakteryzować można ilościowo za pomocą współczynników oporów hydraulicznych. Tematyka badawcza spiętrzenia pod mostem stawiana jest na równi z rozpoznaniem procesów morfodynamicznych zachodzących na długości przeprawy. Spiętrzenie pod mostami określa się wzorami empirycznymi oraz metodą energetyczną wykorzystującą prawo Bernoulliego. Metody empiryczne optymalizuje się przyjmując różne kryteria statystyczne. W artykule porównano spiętrzenie pod mostem obliczone za pomocą dwóch znanych formuł empirycznych Rehbocka oraz Yarnella i porównano je z wynikami badań laboratoryjnych. Kierując się przesłanką, że na ukształtowanie swobodnego zwierciadła wody w rejonie mostu wpływają także opory przepływu, podjęto próbę włączenia prędkości dynamicznej do formuł empirycznych. Na podstawie własnej bazy danych współczynniki wykorzystanych formuł zoptymalizowano z użyciem metody bootstrap resampling w symulacji Monte Carlo. Przeprowadzone analizy wykazały, że formułą najlepiej opisującą zjawisko spiętrzenia pod mostem jest formuła empiryczna zbudowana na podstawie historycznej formuły Yarnella. Uwzględniając w niej prędkość dynamiczną i optymalizując uzyskano średni błąd względny 12.9%. Taka wartość średniego błędu względnego potwierdza słuszność przyjętego podziału pola prędkości na odpływie. Stwierdzono, że metoda bootstrap resampling w symulacji Monte Carlo stanowi użyteczne narzędzie inżynierskie przy optymalizacji formuł w badaniach hydraulicznych. Szczególnie cennym elementem artykułu jest wykorzystywanie próby danych historycznych.

2

Excavations in the vicinity of the antiflood embankments – calculating issues

Grodecki Michał

Studia Geotechnica et Mechanica

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2022

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Vol. 44, nr 2

138--147

EN

According to Polish law, it is prohibited to perform excavations or locate buildings closer than 50 m from the embankment. In order to obtain exemption from this ban, filtration and stability analysis of the embankment and excavation in the flood conditions have to be performed. This paper presents results of the numerical investigations on interactions between excavations and embankment. Complex nature of the problem is presented. Methodology of numerical simulations and real case examples are described.

3

Analiza zagrożenia powodziowego Kazimierza Dolnego

Krawczyk Przemysław, Całka Beata, Bielecka Elżbieta

Roczniki Geomatyki

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2022

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T. 20, z. 4(99)

81--91

PL

Powodzie to jedna z najczęstszych i najbardziej niszczycielskich klęsk żywiołowych na świecie, które mają negatywny wpływ na ludzi, środowisko i gospodarkę. Artykuł ma na celu modelowanie i ocenę ryzyka powodziowego wykorzystując jednowymiarowy model HEC-RAS oraz otwarte dane udostępniane przez Główny Urzędu Geodezji i Kartografii. Obszar badań obejmuje Kazimierz Dolny położony nad Wisłą. Badania przeprowadzono w trzech etapach. Po pozyskaniu danych z numerycznego modelu terenu i elementów doliny rzecznej (np. przekrojów poprzecznych doliny) oraz opracowaniu warstwy szorstkości na podstawie wskaźników Manninga, wymodelowano wody wezbraniowe dla powodzi dziesięcio-, stu- i pięćset letniej. Analiza ryzyka wykazała, że powódź 100-letnia powoduje już dość znaczne szkody w dobrach ludzkich i kulturowych, a powódź 500-letnia znacznie je powiększa, niszcząc 2016 budynków i zalewając obszar o powierzchni niemalże 207 ha.

EN

Flooding is one of the most frequent and devastating natural disasters in the world, generating negative impact to people, environment and economy. The paper aims in flood risk modelling and risk assessment based on one-dimensional HEC-RAS model and open data derived form the Head Office of Geodesy and Cartography. The research area covers the small historic city Kazimierz Dolny located on the Vistula River. The research was carried out in three stages. After digital elevation model and river valley elements (e.g. valley cross sections) data acquisition, as well as elaborating a roughness layer based on Manning's indicators, the ten-, one-hundred- and five-hundred-year floods water were modelled. The risk analysis showed that the 100-year flood is already causing quite significant damage to human and cultural assets, and the 500-year flood significantly increases it, destroying 2,016 buildings and flooding an area of almost 207 hectares.

4

Szkody powodziowe w obiektach budowlanych w latach 1997-2010 na przykładzie terenów południowej Polski

Bajno Dariusz, Grzybowska Agnieszka, Grucki Dawid, Fiutak Marcin

Przegląd Budowlany

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2022

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R. 93, nr 9-10

35--41

PL

W artykule poruszono problem uszkodzeń popowodziowych budynków i budowli, ich skutecznego diagnozowania oraz przywracania do wymaganego stanu użytkowego. Za przykład posłużyły tu dwa okresy powodziowe, lipiec 1997 r. i czerwiec 2010 r. Wskutek naporu wód powodziowych na sąsiadujące ze sobą obiekty budowlane skala powstałych w nich uszkodzeń nie była jednakowa. Autorzy podjęli próbę udzielenia odpowiedzi na pytanie: od czego zależał zakres uszkodzeń budynków i ich elementów składowych, a także zakres późniejszych napraw lub podejmowane decyzje o rozbiórce i czy przed takimi skutkami oddziaływań będzie można ustrzec się w przyszłości? Na czym polegał (jakie stosowano metody) i jak długo trwał proces oczyszczania oraz wysychania przegród, które wchłonęły spore ilości zanieczyszczonej chemicznie i bakteriologicznie wody? Na wybranych przykładach zostanie również opisany proces rewitalizacji uszkodzonych budynków.

EN

The article deals with the problem of flood damage to buildings and structures, their effective diagnosis and restoration to the required operational condition. Two flood periods, July 1997 and June 2010, served as an example here. Due to the pressure of flood waters on adjacent building structures, the scale of damage to them was not the same. The authors attempted to answer the question: what did the extent of damage to buildings and their components depend on, as well as the scope of subsequent repairs or the decisions made about demolition, and whether it would be possible to avoid such effects in the future? What was it (what methods were used) and how long was the process of cleaning and drying the partitions, which absorbed large amounts of chemically and bacteriologically contaminated water? The process of revitalizing damaged buildings will also be described on selected examples.

5

Impact of rainfall trends on flood in Agnéby watershed

Konin N’Da Jean Claude, N’go Yao Alexis, Soro Gneneyougo Emile, Goula Bi Tié Albert

Journal of Water and Land Development

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2022

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no. 52

9--20

EN

The aim of this study is to analyse the spatio-temporal evolution of hydro-rainfall variables in the Agnéby watershed in a disturbed climatic context. Rainfall data from the stations of Arrah, Bongouanou, M’Batto, Akoupé, Céchi, Agboville, Adzopé, Sikensi, Abidjan Airport and Dabou as well as hydrometric data from the stations of Agboville, Offoliguié, M’Bessé and Guessiguié were used. The methodological approach is based on the application of independence and trend tests and spatio-temporal analysis of daily rainfall maxima, duration of consecutive rainfall events, number of rainfall events above a threshold and daily flow maxima. The hypothesis of independence justified the relevance of the choice of variables. The trend test showed the dynamic upward evolution of extreme rainfall and the decrease in the duration of consecutive rainy episodes, in the number of rainy episodes and in the flows feeding the main watercourse. Moreover, spatial analysis of daily maximum rainfall amounts above 120 mm, consecutive maximum rainfall amounts above 160 mm and Gumbel rainfall amounts above 190 mm indicated heavy rainfall in the southern part of the watershed. However, a decrease in rainfall is recorded in the areas covered by the stations of Arrah, Bongouanou, M’Batto, Ce chi and Akoupé. An increase in the flood flow calculated from the Generalized Extreme Value (GEV) between 76.60 m3∙s-1 and 225.70 m3∙s-1 is presented in the main river. The spatio-temporal variation in annual rainfall heights showed a high rainfall in the southern part of the watershed with a decrease in rainfall over the decades (1976-1985 and 1996-2005) followed by an increase over the decades (1986-1995 and 2006-2015). Despite the general decrease in rainfall, extreme rainfall has become frequent, causing flooding in the watershed.

6

Curve Flow-duration-Frequency. The flood modelling regime of the Wadi Mazafran catchment in the north of Algeria

Kourat Sofiane, Touaibia Bénina, Yahiaoui Abdelhalim

Journal of Water and Land Development

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2022

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no. 54

121--130

EN

Synthetic modelling of the flood regime is based on the overall knowledge of the hydrological regime in a catchment. The Flow-duration-Frequency (QdF) modelling is used to combine three parameters characterising flood with its mean or exceeded flow, its characteristic duration, and occurrence frequency. Which of these can be established locally at the extreme mean volume flow rates of a catchment reference hydrometric station? The determination of the reference QdF model in mean (volume) and exceeded flows requires two characteristics reflecting the flood regime in a catchment. The first is the characteristic flood duration and the second is the 10-year quantile of the annual maximum instantaneous flow. The comparison of the local situation to the reference QdF models enables to develop the final QdF model of the catchment and therefore the baseline QdF for exceeded and synthetic mono-frequency hydrographs. These are essential components in the study of flood risk mapping and the estimation of the instantaneous peak distribution from mean daily streamflow series.

7

Compare and evaluate the performance of structural flood risk management options

Dwijendra Ngakan K.A., Majdi Ali

Journal of Water and Land Development

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2022

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no. 54

172--176

EN

One of the most important natural phenomena that causes harmful damage around the world is the occurrence of sudden and severe floods. There are various solutions to deal with floods. Among the structural measures of flood risk management, we can mention the construction of levee, detention basin, channel modification, and a combination of the mentioned measures. Manafwa is a flood-prone area in Uganda currently protected by a 6.6 m high levee. Unfortunately, the existing levee does not have ideal performance, and the probability of failure is very high. Therefore, the main purpose of this study is to compare seven flood management measures in the flood-prone area of Manafwa and to select the best flood risk management proposal. These management measures are: 1) construction of a levee with a height of 6.5 m, 2) construction of a levee with a height of 7 m, 3) construction of a levee with a height of 7.5 m, 4) construction of a levee with a height of 8 m, 5) channel modification, 6) detention basin and 7) a combination of structural measures of channel modification and detention basin. The results show that although building a levee with a height of 8 m is more expensive than other options, but it reduces the expected annual flood damage to about USD30.5 thous.

8

Flow Rate Determination as a Function of Rainfall for the Ungauged Suhareka River

Kusari Laura, Osmanaj Lavdim, Shehu Hana, Bungu Samir

Journal of Ecological Engineering

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2022

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Vol. 23, nr 4

110--121

EN

For ungauged rivers, when there are no hydrological measurements and there is a lack of data on perennial flow rates, the latter one to be determined based on other hydrological data. The river Suhareka catchment represents a similar case. Since there is no data on Suhareka’s flow rates, the authors of this study aimed for the flow rate determination based on rainfall measurements. From the available data on annual precipitation (monthly sums) provided by the Kosovo Hydrometeorological Institute for the Suhareka hydrometric station, the observed monthly rainfall data for 30 years were analysed. Those gaps were initially filled by connecting the hydrometric station in Suhareka with those of Prishtina, Prizren and Ferizaj, and as a result a fairly good fit was ensured. Moreover, the intensity-duration-frequency curves were formed using the expression of Sokolovsky, as a mathematical model of the dependence I (T, P). For a transformation of rainfall into flow, the American method SCS was used. As a result, the equation for the Suhareka River basin was derived, which enabled the determination of maximum inflows, for different return periods. The results obtained through this paper, indicates that even for ungauged river basins the peak flows can be determined from available rainfall data.

9

Zator na Wiśle w rejonie Płocka w lutym 2021 r.

Pawłowski Bogusław, Kolerski Tomasz

Gospodarka Wodna

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2022

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Nr 5

4--8

PL

Powodzie zimowe, związane z zatorami lodowymi, są coraz częściej traktowane jako zjawisko rzadkie lub całkowicie wyeliminowane. Opisana w artykule sytuacja pokazała, że zator nadal może prowadzić do poważnego zagrożenia powodziowego, bardzo trudnego do zneutralizowania. Omówiono sytuację hydrologiczną zimą 2021 r. oraz przyczyny gwałtownego wzrostu ilości lodu w korycie Wisły w rejonie Płocka. Przedstawiono również wyniki pomiaru wypełniania koryta rzeki lodem. Prześledzono proces formowania się zatoru, jego konsekwencje oraz akcję lodołamania. Zwrócono uwagę na postępujące wypłycanie się zbiornika.

EN

Winter floods related to ice jams are increasingly often treated as rare or definitely eliminated phenomena. Situation described in the article indicates that jams may still constitute a serious flood threat, which is very difficult to neutralise. The article discusses the hydrological situation in winter 2021 and the reasons behind sudden accumulation of ice in the Vistula riverbed in the Płock region. It also presents the results of measurement of the riverbed filling with ice. The authors described the jam forming process, its consequences and the ice-breaking action. They also pointed out to the progressing reservoir shallowing.

10

Rola suchego zbiornika przeciwpowodziowego Szalejów Górny na rzece Bystrzyca Dusznicka ze szczególnym uwzględnieniem jego zdolności do redukcji fali wezbraniowej

Połomski Maksymilian

Gospodarka Wodna

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2022

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Nr 6

24--30

EN

Role of the Szalejów Górny flood control dry reservoir on the Bystrzyca Dusznicka River with particular regard to its ability to reduce flood waves

11

Impact of Land Use/Cover Changes on the Flow of the Zarqa River in Jordan

Shammout Maisa'a W., Shatanawi Khaldoun, Al-Bakri Jawad, Abualhaija Mahmoud M.

Journal of Ecological Engineering

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2021

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Vol. 22, nr 10

40--50

EN

This paper investigated the impact of land use/cover changes on the flow of the Zarqa River in Jordan over a period of twenty-eight years. The land use/cover maps were derived using a set of medium spatial images with full scenes for the years 1989, 2002, 2011 and 2017. These images correspond to the river flow data for the same hydrological rainy seasons. The component of the river flow consists of the base-flow, flood and contribution of effluent from treatment plants. Base-flow was separated from hydrographs and effluent contribution was obtained. Runoff coefficient was determined as the ratio of flood volume to rainfall volume. The land use/cover maps were classified as urban fabrics, bare rocks, open rangelands and bare soils, agricultural areas, agro-forestry, and water bodies. During the study period, urban areas increased from 4.87% to 16.14%, and agricultural areas increased from 21.69% to 31.66%. The areas of rangelands and bare soil decreased from 34.91% to 22.57% and bare rocks from 35.98% to 27.57%, respectively. The increase in urban and agricultural areas resulted in runoff coefficient improvement from 1.89% in 1989/1990 to 2.72% for 2016/2017. The results could be useful for planners and decision makers for future flow management in the Zarqa River Basin. The approach and results of this study confirm the findings of similar studies for land and water management.

12

Flood Damage Assessment Using River Water Levels – A Case Study of a Town Located in the North Mazovian Lowland (Poland)

Muszyński Robert, Kocur-Bera Katarzyna

Journal of Ecological Engineering

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2021

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Vol. 22, nr 2

200--212

EN

Flooding is a very dangerous phenomenon, causing both direct and indirect damage. The preventive actions result from the awareness of the danger and consequences of floods. In the affected areas, an important stage of management includes preventing and minimizing losses. The article presents a method for estimating the flood losses using flood hazard maps and taking into account the updated prices. Particular emphasis was placed on different risk levels of risk that are due to a flood in the examined location. The analysis was performed for the city through which three rivers flow. The generally available flood hazard maps in the Computerized National Protection System (Polish acr. ISOK), which include the information on the depth of the floodwater and land use classes, help estimate the financial losses. The research has shown that the greatest material losses caused by flooding are usually incurred in residential areas. On the basis of the results obtained, it was also determined that asset revaluation with time has a significant impact on the level of estimated losses. The article uses the methodology implemented in the Flood Risk Maps, which present the negative consequences for the population and the scope of flood losses. The results were compared with the author’s interpretation.

13

Zagrożenie powodziowe Gdańska Przyczyny, przebieg i skutki powodzi w lipcu 2001 r. w Gdańsku. Część II

Majewski Wojciech

Gospodarka Wodna

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2021

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Nr 12

16--20

PL

W artykule, który stanowi II część publikacji (Gospodarka Wodna 6/21 str. 9–16) przedstawiono przyczyny i przebieg powodzi miejskiej w Gdańsku, jej skutki w różnych miejscach Gdańskiego Węzła Wodnego oraz doraźnie wykonane naprawy zniszczonej infrastruktury miejskiej. Bezpośrednią przyczyną powodzi był intensywny opad deszczu skoncentrowany głównie na obszarze zlewni Kanału Raduni (KR), przebiegającego u podnóża wzgórz morenowych i wzdłuż szlaku komunikacyjnego prowadzącego do Gdańska. Zlewnia KR uległa w ostatnich latach intensywnej urbanizacji, co spowodowało uszczelnienie jej znacznej powierzchni i przyspieszenie spływu powierzchniowego.

EN

The paper, which is the 2nd part of the publication (Gospodarka Wodna 6/21 pp. 9–16), presents the reasons and the run of urban flood in Gdańsk, its results in various parts of Gdańsk Water Node and immediate repairs of damaged city infrastructure. The basic cause of the flood was a very intensive rainfall concentrated on the catchment of Radunia Channel (RCh) which runs at the foot of morraine hills and along the main road leading to Gdańsk. The catchment of RCh was in recent years intensively urbanized, what resulted in the sealing of the terrain and accelerating of surface runoff.

14

Zagrożenie powodziowe Gdańska. Gdański Węzeł Wodny. Część I

Majewski Wojciech

Gospodarka Wodna

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2021

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Nr 6

9--16

PL

Prezentowana I część artykułu Zagrożenia powodziowe Gdańska obejmuje opis Gdańskiego Węzła Wodnego, w skład którego wchodzi system rzek i kanałów wraz z istniejącą infrastrukturą hydrotechniczną w postaci progów, jazów i przepustów. Na tym obszarze, w lipcu 2001 r. wystąpiła powódź błyskawiczna, spowodowana intensywnym opadem deszczu. Przedstawiono charakterystykę elementów wchodzących w skład GWW oraz warunków przepływu.

EN

This 1st part of the article entitled Flood threat to Gdańsk describes the Gdańsk Water Note, composed of a system of rivers and channels together with the existing hydraulic infrastructure including sills, weirs and culverts. In July 2001, a flash flood occurred in this area, caused by intensive precipitations. The article presents the characteristics of GWN’s elements and the flow conditions.

15

Geospatial Analysis of the Impact of Flood and Drought Hazards on Crop Land and Its Relationship with Human Migration at the District Level in Uttar Pradesh, India

Islam Zubairul, Singh Sudhir Kumar

Geomatics and Environmental Engineering

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2021

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Vol. 15, no. 4

117--127

EN

The main objective was to explore the connection between flood and drought hazards and their impact on crop land and human migration. The Flood and Drought effect on Cropland Index (FDCI), hot spot analysis and the Global Regression Analysis method was applied for the identification of the relationship between human migration and flood and drought hazards. The spatial pattern and hot and cold spots of FDCI, spatial autocorrelation and Getis-OrdGi* statistic techniques were used respectively. The FDCI was taken as an explanatory variable and human migration was taken as a dependent variable in the environment of the geographically weighted regression (GWR) model which was applied to measure the impact of flood and drought hazards on human migration. FDCI suggests a z-score of 4.9, which shows that the impact of flood and drought frequency on crop land is highly clustered. In the case of the hot spots analysis, out of seventy districts in Uttar Pradesh twenty-one were classified as hot spot and eight were classified as cold spots with a confidence level of 90 to 99%. Hot spot indicate maximum and cold spots show minimum impact of flood and drought hazards on crop land. The impact of flood and drought hazards on human migration show that there are fourteen districts where migration out is far more than predicted while there are ten districts where migration out is far lower.

16

Designation of Flood Risk Zones Using the Geographic Information System Technique and Remote Sensing Data in Wasit, Iraq

Rasn Kouther Hasheem, Nsaif Qutaiba Abdulwahhab, Al-Obaidi Mudhar A., John Yakubu Mandafiya

Geomatics and Environmental Engineering

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2021

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Vol. 15, no. 3

129--140

EN

Floods are a great concern for people and infrastructure, and this is an is‑sue which has increased in several regions around the globe in recent years. This study aims to evaluate flood risk areas and create a flood risk map using in‑tegrated remote sensing data and a geographic information system (GIS) in the Wasit governorate – eastern Iraq. Specifically, GIS‑based multi‑criteria analy‑sis (MCA) was used to map flood hazard areas using a four‑criteria layer which is as follows: flow accumulation, slope, rainfall, and elevation. These four layers are standardized and combined using the overlay approach in ArcGIS software and a final map was produced. The study area was divided into five zones based on the results map, namely: very low, low, medium, high, and very high, according to the flood risk area. The resulting map indicates that over 60% of the study area is likely to experience a high and very high level of propensity of flooding. This study could be useful for government planners and decision‑makers to predict potential flooding areas and enhance flood management plans.

17

Powódź stulecia w Niemczech

Geodeta : magazyn geoinformacyjny

|

2021

|

nr 8

22--23

18

Żuławska powódź z 1888 roku obrazami zapisana

Lidzbarski Ryszard

Forum Eksploatatora

|

2021

|

Nr 3 (114)

56-64

PL

Na przestrzeni wieków mieszkańcy Żuław Wiślanych zmagali się z licznymi powodziami. Wiele z nich powodowało katastrofalne zniszczenia. Powódź z 1888 roku nie była największą, ale przyśpieszyła realizację odkładanych od 127 lat inwestycji, mających ograniczyć skutki występujących powodzi. W efekcie wykonano w 1895 roku nowe Ujście Wisły do morza, przebudowano obwałowania jej oraz Nogatu. W okolicy Mątowskiego Cypla dokonano kolejnej zmiany podziału rozpływu wód tych rzek.

19

Środowiskowe skutki powodzi na Żuławach Wiślanych

Lidzbarski Ryszard

Forum Eksploatatora

|

2021

|

Nr 2 (113)

74-81

PL

Wędrując w czasie po Żuławach Wiślanych nie trudno dostrzec wszech obecnej wody, przyczyniającej się do urodzaju i bogactwa tych ziem. Niestety żyzne tereny delty Wisły przez wieki narażone były również na niszczycielskie działanie jej nadmiaru. Skutkiem były liczne powodzie wywierające piętno w naturalnym środowisku.

20

Mapping food extend and its impact on land use/land cover and settlements variations: a case study of Layyah District, Punjab, Pakistan

Soomro Shan-e-hyder, Hu Caihong, Boota Muhammad Waseem, Soomro Mairaj Hyder Alias Aamir, Jian Shengqi, Zafar Zeeshan, Li Xiaoping

Acta Geophysica

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2021

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Vol. 69, no. 6

2291--2304

EN

Floods are the most frequent and most distractive natural disaster around the globe. Pakistan is facing frequent flooding since 1929 and foods in the Indus river basin cost more than 7000 lives and caused mighty changes in land use and land covers (LULC) since 1947. District Layyah hit by food on August 1, 2010. Landsat ETM+ with 30 m spatial resolution was utilized to investigate the LULC changes in district Layyah for the 2010 food. It was revealed water area increased 8.05% from July 3 (379.13 km2 ) to August 20 (656.02 km2 ) in district Layyah. Vegetation cover increased from 1149.62 km2 on July 3 to 1842.23 km2 on August 20 in district Layyah and showed a 20.13% increment. Barren/built-up area showed a decrement of 28.18% from 1911.72 km2 in pre-food analysis to 941.90 km2 in the post-food analysis. Total 15 union councils (UC) of district Layyah were affected by food from which 10 lies in tehsil Layyah and 5 belongs to tehsil Karor Lal Esan. Flood affects 177 settlements in district Layyah from which 156 belong to tehsil Layyah and 21 were from tehsil Karor Lal Esan. These results suggest that the impacts of the food on LULC need more attention to cope with the challenge of frequent flooding and impacts in Pakistan.