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1

Assessment of Large River Basin Approaching GIS and Computation of Simulation Techniques Using Latest Software

Patil Gauri, Kherde Rajesh

Ecological Engineering & Environmental Technology

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2024

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Vol. 25, iss. 1

360--368

EN

Advancements in computer techniques with a geographic information system (GIS) interface have greatly contributed to simulating river basins with a reasonable level of accuracy. It becomes possible to analyze and model various aspects of a river basin, such as water flow, land use, and hydrological processes. Water is essential for sustaining life. Previous studies revealed that effective watershed management requires an understanding of the impact of rainfall in the catchment area, but due to poorly gauged river basin, it becomes difficult to predict the hydrological response. In this context, hydrologic engineering centre – hydrologic modeling system (HEC-HMS) model is used to simulate surface runoff in different watersheds. The study simulated the Wainganga river basin, geographically located between longitude 78°0’–80°45’ E and latitudes 19°41’–22°50’ N. The model utilizes eighteen year data for rainfall extracted from Indian Meteorological Department with 0.25×0.25 grid. Similarly, evapotranspiration and observed discharge were extracted from India water resource information system. Shuttle radar topography mission dataset with digital elevation model of 30×30 m spatial resolution, extracted from United States of Geological Survey was an input to HEC-HMS 4.10. Different approaches with changing parameters were implemented for suitable simulation. SCS curve number method with Muskingum routing was implemented for study. The purpose of study was to compare the calculated and observed discharge as well as test model performance. Nash efficiency coefficients (NSE) were used for testing performance. The results show a satisfactory performance with NSE above 0.7 for basin. The description outlines, model can be used for assessing the behavior of large river basin.

2

Assessment of the risk of flooding in an urbanized area in response to heavy rains: case study of the Warsaw Chopin Airport

Barszcz Mariusz, Paweł, Baryła Anna, Stańczyk Tomasz, Brandyk Andrzej

Zeszyty Naukowe SGSP / Szkoła Główna Służby Pożarniczej

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2023

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Nr 87

121--139

EN

The paper presents the adaptation of the hydrodynamic Storm Water Management Model (SWMM) for the subcatchment area of the Służewiecki Stream in Warsaw, the major part of which is the area of the Chopin Airport. The SWMM model was used for calculating the water outflow from the studied urbanized area in response to rainfall with the probabilities of 20 and 10%, and then to assess the possibility of flooding as a result of rainwater spillage from the Airport drainage system. The scope of the work also comprised assessing the impact of the existing retention tanks at the Airport on the reduction of maximum flows in the Służewiecki Stream channel. Simulations in response to the rainfall event with a probability of 10% have shown that there are locations (sewer manholes) within the airport area where short-term rainwater overflows may potentially occur. Retention of rainwater in tanks and flow control through gate valves have a significant impact on a reduction of flows in the Słuzewiecki Stream, thus reducing the risk of flooding in the studied catchment area.

PL

W artykule przedstawiono adaptację hydrodynamicznego modelu Storm Water Management Model (SWMM) dla zlewni cząstkowej Potoku Służewieckiego w Warszawie, której przeważającą część stanowi teren Lotniska im. Chopina. Model SWMM zastosowano do obliczania odpływu wód z badanego obszaru zurbanizowanego w reakcji na opady deszczu o prawdopodobieństwach wystąpienia 20% i 10%, a następnie do oceny możliwości występowania podtopień w wyniku wylewania się wód deszczowych z systemu odwodnienia Lotniska. Zakres pracy obejmował również ocenę wpływu istniejących zbiorników retencyjnych na terenie lotniska na redukcję przepływów maksymalnych w kanale Potoku Służewieckiego. Symulacje dla opadu o prawdopodobieństwie 10% wykazały, że na terenie lotniska są miejsca (studzienki kanalizacyjne), w których potencjalnie mogą występować krótkotrwałe wylewy wód deszczowych. Retencjonowanie wód deszczowych w zbiornikach i sterowanie przepływami za pomocą zasuw ma duży wpływ na redukcję przepływów w Potoku Służewieckim, a tym samym na zmniejszenie zagrożenia występowania podtopień na obszarze badanej zlewni.

3

Strength reduction method in the stability assessment of vegetated slopes

Świtała Barbara

Architecture Civil Engineering Environment

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2023

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Vol. 16, no. 2

151--159

EN

The thoughtful design and mitigation of ecological slope stabilization measures rely heavily on the reliable assessment of the stability of vegetated slopes. This is a complex problem due to the many aspects of vegetation presence that must be taken into account. The numerical model should be able to consider mechanical root reinforcement and root water uptake, which can lead to soil desaturation. This paper presents the application of the strength reduction method to the Modified Cam-Clay model for unsaturated, root-reinforced soils, which allows for the quantitative estimation of slope stability. The technique is implemented in finite element software and tested using several numerical examples. Firstly, the sensitivity of the factor of safety to changes in root constitutive parameters is investigated. In the second example, the stability of the modelled slope is assessed under rainfall of a certain duration followed by progressively modifying soil strength parameters until failure occurs. Furthermore, slope stability is assessed for various durations of the rainfall period.

4

Digital Elevation Model resolution and its impact on the spatial pattern of rainfalltemperature prediction at the catchment scale: The case of the Mille catchment, Ethiopia

Bati Hirpo Gudeta

Meteorology Hydrology and Water Management. Research and Operational Applications

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2022

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Vol. 10, Iss. 1

26--46

EN

In a mountainous catchment, understanding the interaction between DEM resolution and climatic variables is essential for the accurate spatial interpolation of areal mean monthly and annual rainfall and temperature, which is required as an input for further applications such as hydrological and hydraulic modeling, agriculture, and environmental conservation. This case study applied the geostatistical interpolation technique, kriging with external drift (KED), with a digital elevation model (DEM) with various horizontal resolutions, which were used to assess the effects of the DEM horizontal resolutions on the spatial distributions of rainfall and temperature by focusing on interpolating the mean monthly and annual rainfall and temperature over a spatially diversified catchment. The assessment was undertaken using spatially and temporally complete sampled historical climatic datasets, and consequently, the spatial pattern of monthly and annual rainfall (temperature) from east to the west gradually increases or decreases following the DEM elevation increment along the same direction. As a result, the finer-resolution DEM (90-m SRTM-DEM) had a considerable impact on predicting the mean monthly minimum and maximum temperatures, whereas the resampled 500-m SRTM-DEM performed relatively better in mean monthly and annual rainfall and annual minimum temperature estimation values.

5

The analysis of the El Niño phenomenon in the East Nusa Tenggara Province, Indonesia

Karuniasa Mahawan, Pambudi Priyaji Agung

Journal of Water and Land Development

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2022

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no. 52

180--185

EN

Climate change causes various events, such as El Niño , and we experience their larger frequency. This study based on a quantitative approach uses observation data from the Umbu Mehang Kunda Meteorological Station and the Ocean Niño Index (ONI). As a result, East Sumba, which has an arid climate, has more challenges in dealing with drought and water deficits during El Niño. This study identifies rainfall when the El Niño phenomenon takes place in East Sumba through data contributing to the ONI value and dry day series from 1982 to 2019. The analysis was carried out by reviewing these data descriptively and supported by previous literature studies. The research found that there was a decrease in the accumulative total rainfall in El Niño years. The annual rainfall in the last six El Niño events is lower than the annual rainfall in the first six El Niño events. The dry day series is dominated by an extreme drought (>60 days) which generally occurs from July to October. This drought clearly has a major impact on livelihoods and causes difficulties in agriculture as well as access to freshwater. This results in crop failure, food shortages, and decreased income. The phenomenon triggers price inflation in the market and potential increase in poverty, hunger, and pushes the country further away from the first and second Sustainable Development Goals. This phenomenon and problems related to it need to be dealt with by multistakeholders.

6

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.

7

Climate Change and its Effect on the Energy Production from Renewable Sources – A Case Study in Mediterranean Region

Gjika Eralda, Basha Lule, Sokoli Arnisa

Journal of Ecological Engineering

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2022

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Vol. 23, nr 12

285--298

EN

In terms of climate forecasting, the Mediterranean region is among the most difficult. It is correlated with the five significant subtropical high pressure belts of the oceans and is symbolized by dry and hot summer and cold and rainy winter. Due to its location in the area, Albania is particularly susceptible to climatic changes. It has been noted that summertime sees the greatest temperature increases. More intense heat waves that stay longer and occur more frequently are anticipated in the eastern Mediterranean. The seasonal patterns of precipitation have not changed, but the amount of rain has become more intense. The effects of climate change have drawn attention to various renewable energy sources, including solar and wind power. In this study, the changes and prospective in average temperature, rainfall, humidity, CO2 emission and their impact in energy production were investigated. Several different models such as Auto Regressive Integrated Moving Average method; Prophet algorithm; Elastic-Net Regularized Generalized Linear Model; Random Forest Regression models; Prophet Boost algorithm; have been built for the study and prediction of each variable. The appropriate models are used to determine the anticipated values of the indicators for a period of four years. The prediction shows an increase in CO2 emission which leads to a decrease in energy production by hydropower. These findings suggest the use of other renewable sources for energy production in the country and the Mediterranean region.

8

The Variability of Surface Chlorophyll-a in Lake Rawa Pening within Five-Month Observations

Amelia Karla, Nuringtyas Satria Bagus, Setiawan Riza Yuliratno, Setyobudi Eko, Adharini Ratih Ida, Aryudiawan Candra, Maslukah Lilik

Ecological Engineering & Environmental Technology

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2022

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Vol. 23, iss. 4

173--178

EN

Lake Rawa Pening is a natural lake in the Semarang Regency of Central Java Province, Indonesia, and its existence is pivotal to the surrounding communities as it provides ecological, economic, and social benefits. The ecosystem health of Rawa Pening can be represented by chlorophyll-a concentration because it indicates phytoplankton biomass, nutrient availability, and fish resources. Hence, the present study aims to disentangle the monthly variability of surface chlorophyll-a in Rawa Pening Lake by analyzing water samples that were collected once a month from nine stations within five-month observations (September 2020 to January 2021). The samples were analyzed using spectrophotometric method. Results showed that the highest surface chlorophyll-a concentration (23.33 mg/m3) took place in December, while the lowest concentration (12.64 mg/m3) occurred in October. The monthly variability of surface chlorophyll-a was likely controlled by variation of rainfall, with the highest (18.72 mm) and the lowest (12.33 mm) rainfall happened in December and October, respectively. The present study also indicates the anthropogenic activities such as agricultural activities, floating food stands, aquaculture, and tourist boats may contribute to surface chlorophyll-a variability in Rawa Pening Lake.

9

Rainfall and rainy days trend and ENSO phenomena in Himalayan Kingdom of Bhutan

Sharma Vasker, Adhikari Kirtan

Acta Geophysica

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2022

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Vol. 70, no 4

1855--1869

EN

The study explores the seasonal rainfall and rainy days trend in the Himalayan Kingdom of Bhutan. Mann-Kendall and Sen’s slope test was applied to detect the trend and magnitude of the trend for both the rainfall and rainy days. The trends are also analyzed with respect to the elevation of the climatic stations. Further, an attempt has been made to recognize the El-Ni ño-Southern Oscillation (ENSO)-rainfall interaction using station-based rainfall with the ENSO cycle considering the period of 33 years. Cross-correlation of ENSO and rainfall with respect to elevation has also been presented. The trend analysis showed that in the localized regions, both the rainfall and rainy days trend was significantly declining, however, the trend in most of the stations is hardly conspicuous which may be attributed to the influence of the orographic phenomena. From the ENSO-rainfall assessment, it was observed that rainfall in the southern foothills correlates negatively with the ENSO phenomena indicating intense rainfall after 1–2 months of the cooling phase of the Pacifc Ocean. However, such an ENSO effect is not observed in the majority of the meteorological stations which may be attributed to the location of the station in the mountainous region where the topography affects the rainfall variation.

10

Assessment of urbanization impact on urban heat island effect and rainfall for the Surat city

Sharma Arpit, Kale Ganesh D.

Acta Geophysica

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2022

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Vol. 70, no 1

243--264

EN

Population growth and urbanization lead to urban heat island (UHI) phenomenon. Urbanization is occurring at a very high rate in the Surat city. Thus, the study of the urbanization impact on the UHI effect for the Surat city is performed in the present study through studying the impact of land use land cover on the land surface temperature of urban and sub-urban areas of the Surat city over the period May 1998 to May 2018. Also, these effects are compared with that of a nearby sub urban taluka Kamrej, which showed that temperature in urban areas is more than that of the sub-urban areas. Aforesaid facts clearly showing the existence of the UHI effect in the Surat city. As urbanization contributes to climate change, its effects on rainfall are studied by comparing rainfall trends of urban and sub-urban areas of the Surat city and nearby sub-urban area Kamrej. Trend analysis showed that trend magnitude values are higher for the urban areas than sub-urban areas, indicating that UHI effect increases rainfall in urban areas. Hotspot analysis is also performed for the Surat city corresponding to May 2018 to recognize hot spots and cold spots. As the Surat city is highly urbanized, thus, hotspots are more than cold spots.

11

214Bi/214Pb radioactivity ratio three-year monitoring in rainwater in Prague

Ambrosino Fabrizio, Thinová Lenka, Hýža Miroslav, Sabbarese Carlo

Nukleonika

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2020

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Vol. 65, No. 2

115--119

EN

Continuous monitoring of natural gamma radiation in air has been carried out, during December 2014 – January 2018, with 1-min cyclic measurement in Prague, Czech Republic using a NaI(Tl) probe. The 214Bi/214Pb ratio as a tracer in rainwater has been investigated to study its variations related to both the ambient dose equivalent rate per hour and the amount of rainfall. A hybrid methodology for time series analysis, composed of the aggregation of two signal decomposition methods (multiple linear regression and empirical mode decomposition) and one forecasting method (support vector regression), has been applied to identify the anomalies in the studied signals in order to better find correlations among them. The results show a strong correlation between the ambient dose equivalent rate and the 214Bi/214Pb ratio values and between both these signals and rainfall amount≥5 mm/h. Furthermore, the considered descendants of radon are mainly responsible for the overall ambient dose equivalent rate.

12

Wheat yield response and seasonal salt profile evolution under irrigation with saline waters in a semi-arid region

Cheraghi Seyed A. M.

Journal of Water and Land Development

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2020

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no. 44

26--32

EN

Scarcity of fresh water resources is the major constraint for agricultural development in Iran as in many other regions with arid and semi-arid climate. With the pressure on fresh water resources, the use of un-conventional water resources including brackish, saline and sewage water has received greater attentions in recent years. The objective of this study was to assess the impact of farmers' practices using saline groundwater on wheat yield and soil salinity in a Mediterranean climate of Fars province in southern Iran. The study was carried out in several commercial wheat production regions for two years. Chemical analysis of irrigation waters, volume of applied irrigation water, electrical conductivity of soil saturation extract (ECe) and yield were measured in each field. General information on agronomic practices was also collected using a questionnaire. Results demonstrate that waters with salinities higher than what has been classified as “suitable for irrigation” are being used for the production of wheat crop. Analysis of wheat yield response to saline irrigation water showed that for water salinities up to 10.7 mS∙cm–1 (threshold value) variation in yield was relatively minor, above which wheat yield decreased at a greater rate. Root zone salinity profiles showed the effect of winter rainfall in reducing soil salinity. It is concluded that although acceptable yields are obtained with some of the highly brackish waters, over application of these waters would threaten the sustainability of crop production in the region.

13

Rainfall-river discharge modelling for flood forecasting using Artificial Neural Network (ANN)

Obasi Arinze A., Ogbu Kingsley N., Orakwe Chukwuemeka L., Ahaneku Isiguzo E.

Journal of Water and Land Development

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2020

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no. 44

98--105

EN

This study is aimed at evaluating the applicability of Artificial Neural Network (ANN) model technique for river discharge forecasting. Feed-forward multilayer perceptron neural network trained with back-propagation algorithm was employed for model development. Hydro-meteorological data for the Imo River watershed, that was collected from the Anambra-Imo River Basin Development Authority, Owerri – Imo State, South-East, Nigeria, was used to train, validate and test the model. Coefficients of determination results are 0.91, 0.91 and 0.93 for training, validation and testing periods respectively. River discharge forecasts were fitted against actual discharge data for one to five lead days. Model results gave R2 values of 0.95, 0.95, 0.92, 0.96 and 0.94 for first, second, third, fourth, and fifth lead days of forecasts, respectively. It was generally observed that the R2 values decreased with increase in lead days for the model. Generally, this technique proved to be effective in river discharge modelling for flood forecasting for shorter lead-day times, especially in areas with limited data sets.

14

Assessment of hydrological alteration from 1996 to 2017 in Brantas watershed, East Java, Indonesia

Indarto Indarto, Andiananta Pradana Hendra, Wahyuningsih Sri, Umam Muhammad K.

Journal of Water and Land Development

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2020

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no. 46

121--130

EN

Climate, land use, and land cover change can propagate alteration to the watershed environment. The interaction between natural and human activities probably accelerates the change, a phenomenon that will generate serious environmental problems. This study aims to evaluate the change in the hydrological regime due to natural and human-induced processes. The study was conducted in Brantas watershed, Indonesia, which is the largest watershed in East Java. This area is populated by more than 8 million inhabitants and is the most urbanized area in the region. An analysis of rainfall time series use to shows the change in natural phenomena. Two land-use maps at different time intervals were used to compare the rapid development of urbanization, and the discharge from two outlets of the sub-watersheds was employed to assess hydrological changes. The indicator of hydrological alteration (IHA) method was used to perform the analysis. The daily discharge data are from 1996 to 2017. The research results show an increase in flow (monthly, 1-day, 3-day, 7-day, 30-day, and 90-day flows) in the two sub-watersheds (Ploso and Kertosono) from the pre-period (1996–2006) to the post-period (2007–2017).

15

Zagospodarowanie wód opadowych i roztopowych na przykładzie mareckiego systemu kanalizacji deszczowej

Urbanek Maciej, Zgoła Andrzej, Hosaja Mateusz, Chojecka Justyna

Gaz, Woda i Technika Sanitarna

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2020

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Nr 7-8

23--31

PL

Niniejszy artykuł przedstawia racjonalizatorskie podejście do problemu zagospodarowania wód opadowych i roztopowych na przykładzie mareckiego systemu kanalizacji deszczowej, przybliżając kolejne etapy działania gminy od sporządzenia prostych modeli na podstawie wzoru Błaszczyka aż do opracowania zaawansowanych modeli hydrodynamicznych, przy zastosowaniu oprogramowania SWMM (Storm Water Management Model) w oparciu o Polski Atlas Natężeń Deszczów Miarodajnych (PANDa) [8]. Zwraca się szczególną uwagę na kompleksowe podejście do projektowania sieci kanalizacji deszczowej wraz z analizą warunków hydrogeologicznych oraz z uwzględnieniem topografii miasta i możliwości wykorzystania istniejących zbiorników wodnych oraz rowów melioracyjnych, jak również w odniesieniu do koncepcji przebudowy ulic [9]. Podejście takie pozwala na efektywne wydatkowanie pieniędzy z budżetu gminy oraz prowadzi do konsekwentnego powstawania sprawnego systemu zagospodarowania wód opadowych na terenie całego miasta. Należy dążyć do jak największego wykorzystania wód opadowych na obszarze ich powstawania oraz do minimalizowania ilości wód odprowadzanych bezpowrotnie do cieków płynących, np. do rzek. Autorzy prezentują prawidłowe podejście do modelowania oraz projektowania systemu sieci kanalizacji deszczowej, z uwzględnieniem możliwie wysokiego udziału retencji wód opadowych oraz rewitalizacji istniejących zbiorników wodnych (stawów pogliniankowych), co dodatkowo poprawi walory rekreacyjne miasta.

EN

The article presents a rationalized approach to the problem of stormwater management based on the example of rainwater drainage system in Marki, bringing closer the successive stages of municipal authorities, from the simple models based on the Błaszczyk formula to the advanced hydrodynamic models using the SWMM (Storm Water Management Model) software based on the Polish Atlas of Rains Intensities PANDa [1]. Particular attention is paid to a complex approach to designing a rainwater drainage system with an analysis of hydrogeological conditions and taking into account the topography and the possibility of using existing water reservoirs and ditches, also referring to a concept design for streets redevelopment [2]. Such an approach allows to spend money from the municipal budget in more effective way and leads to the consistent creation of an efficient stormwater management system throughout the city. One should strive to maximize the use of rainwater in the area of the rainfall and to minimize the amount of water irretrievably released to watercourses, e.g. rivers. The authors present the valid approach to modeling and designing a rainwater drainage system, considering the highest share of stormwater retention and the revitalization of existing water reservoirs (clay ponds), which will further improve the recreational value of the city.

16

Understanding the hydrometeorological characteristics and relationships in the semiarid region of Maharashtra (western India): implications for water management

Todmal Rahul S.

Acta Geophysica

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2020

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Vol. 68, no. 1

189--206

EN

In spite of enormous investment for water harvesting in Maharashtra, the issue of water defciency persist. Therefore, with the proper understanding of recent (1975–2014) hydrometeorological characteristics in the semiarid region of Maharashtra, the study endeavored to suggest management strategies to optimize the water resources. To understand the inherent characteristics of rainfall, runof, dam storages and groundwater, statistical techniques including descriptive statistics, correlation, regression and Student’s t test were applied. The monsoon rainfall has notable control over the water resources. As the study region characterized by signifcantly low water availability with high variability which is accountable for higher frequency and intensity of drought, it should be prioritized while formulating a judicial plan for water management. The major rivers of Maharashtra follow the unimodal pattern of rainfall. Whereas the study area displays a peculiar character of the bimodal and unimodal regimes of rainfall and runof, respectively, this highlights the role of hydrological losses. However, it also indicates that there is a wide scope to harvest surface water, particularly during the months of September and October. Interestingly, the inter-annual variability in the extreme rainfall and runof events over the study basins is observed to be higher in India. Most of the water (>50%) received during fashy rainfall events drains out through fashy discharges. The impoundment of this water and modifed irrigation schedule by considering the recent hydrological characteristics may diminish the variability and defciency of surface and subsurface water. Furthermore, for the precise forecast of water availability in the study area, ENSO condition needs to incorporate, as it has a signifcant connection with rainfall and runof.

17

The added value of spatially distributed meteorological data for simulating hydrological processes in a small Mediterranean catchment

Gara Ahlem, Gader Khouloud, Khlifi Slaheddine, Vanclooster Marnik, Jendoubi Donia, Bouvier Christophe

Acta Geophysica

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2020

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Vol. 68, no. 1

133--153

EN

The purpose of this paper was to demonstrate the added value of the spatial distribution of rainfall and potential evapotranspiration (PE) in the prediction of the discharge for a small Mediterranean catchment located in the Medjerda basin in Tunisia, i.e. the Raghay. We compare therefore the performance of a conceptual hydrological model available in the ATHYS platform, using global and spatial distributed input data. The model was implemented in two diferent ways. The frst implementation was in a spatially distributed mode, and the second one was in a non-distributed lumped mode by using spatially averaged data weighed with a Thiessen-interpolated factor. The performance of the model was analysed for the distributed mode and for the lumped mode with a cross-validation test and through several modelling evaluation criteria. Simultaneously, the impact of the spatial distribution of meteorological data was assessed for the two cases when estimating the model parameters, the fow and water amounts, and the fow duration curves. The cross-validation of the split-sample test shows a preference for the spatially distributed model based on accuracy criteria and graphical comparison. The distributed mode required, however, more simulation time. Finally, the results reported for the Raghay indicated that the added value of the spatial distribution of rainfall and PE is not constant for the whole series of data, depending on the spatial and temporal variability of climate data over the catchment that should be assessed prior to the modelling implementations.

18

Impact of convection and stability parameters on lightning activity over Andhra Pradesh, India

Umakanth N., Satyanarayana G. Ch., Simon B., Kumar Prashant, Rao M. C.

Acta Geophysica

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2020

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Vol. 68, no. 6

1845--1866

EN

This paper brings out the interconnection of fash rate density (FRD) with convection and stability parameters over Andhra Pradesh (AP), India. The convection parameters include rainfall, relative humidity, specifc humidity, surface air temperature (SAT) and air temperature (at 850 mb). The stability parameters include convective available potential energy (CAPE), lifted index, K-index, total totals index (TTI), humidity index and total precipitable water. Both convective and stability parameters indicate good correlation with lightning activity. SAT and AT 850 mb have shown good correlations with lightning, which is a clear indication of interaction between warm air and dry air. CAPE and TTI have shown strong positive correlation with lightning activity. The correlation coefcient between FRD and CAPE is 0.81. We have also studied the infuence of convective and stability parameters during lightning and no lightning activity. Later, we also attempted the estimation of lightning activity by using artifcial neural network model. By using convection and stability parameters, six learning algorithms were used for training the artifcial neural network. Scaled conjugate gradient backpropagation training algorithm has given the better estimation, whereas resilient backpropagation training algorithm has shown the poor estimation of FRD.

19

Analysis of various thermodynamic instability parameters and their association with the rainfall during thunderstorm events over Anakapalle (Visakhapatnam district), India

Umakanth N., Satyanarayana G. Ch., Simon B., Rao M. C., Kumar M. Tanooj, Babu N. Ranga

Acta Geophysica

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2020

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Vol. 68, no. 5

1549--1564

EN

Thunderstorm events usually take place in cumulonimbus clouds which are complemented with intense rainfall and highspeed winds. In general, rainfall parameter has massive signifcance when compared to other parameters. In this paper, a group of thunderstorm-related stability parameters were analyzed for pre-monsoon season only. Later, we also tried to study the association between thunderstorm-related stability parameters and rainfall parameter in pre-monsoon season over Anakapalle (Visakhapatnam district) during 2001–2010. We have utilized ERA-Interim ECMWF reanalysis daily datasets for this study. We also tried to compare IMD thunderstorm occurrence days with NOAA CPC-calculated rainfall days in pre-monsoon season over Anakapalle region for every year during 2001–2010. Out of those parameters, upward vertical velocity, convective available potential energy, K-index (KI), humidity index and total totals index parameters have shown good thresholds supporting the rainfall activity during pre-monsoon season. Later, we have also attempted the prediction of DCI and KI parameters over Anakapalle region using artifcial neural network (ANN) and auto-regressive moving average (ARMA) techniques. In comparison between the two techniques, ANN technique has shown good correlation with ERAInterim ECMWF reanalysis data.

20

Natężenia opadu deszczu przyjmowane do różnych celów

Dąbrowski Wojciech

Rynek Instalacyjny

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2019

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Nr 10

80--84

PL

W artykule przedstawiono przegląd literatury dotyczącej wyboru natężenia opadu określanego dla różnych celów. Rozpoczęto od wartości przyjmowanych do wymiarowania lokalnych systemów odwodnień, poprzez krótkie kanały, do dużych systemów kanalizacyjnych. Opisano szczegółowo dwie racjonalne metody wymiarowania kanalizacji stosowane w Polsce. Następnie podano wartości intensywności opadów przyjmowane do projektowania systemów oczyszczania wód deszczowych.

EN

A literature review on different rain intensities selected for different purposes was presented. The selection started from the values used for designing of local area draining systems, through short sewers to large sewerage systems. Two rational methods used for designing of sewerage systems in Poland were described in details. Then selection of rain intensities were described for designing of storm water treatment systems.