Overflow Data of Rainwater Discharge Systems Determined from Run off Simulation of Pluviograph Records

1984 ◽  
Vol 16 (8-9) ◽  
pp. 297-309
Author(s):  
R Pecher
Keyword(s):  
Statistical Analysis ◽  
Rainfall Data ◽  
Annual Rainfall ◽  
Rainfall Analysis ◽  
Rainfall Variation ◽  
Runoff Variation ◽  
Sewer Systems ◽  
Run Off ◽  
Combined Sewer ◽  
Runoff Model

In the last years, the relieving activity of overflow structures in combined sewer systems was mainly determined by statistical analysis of rainfall data. Due to the rain lost on the surface of a drainage area and to the flow rétardation through the sewer network, the resulting runoff variation differs a lot from the rainfall variation. Therefore, the rainfall measurements of 4 rain gaging stations in Hamburg with a total of 67 recorded years and a rain gaging station in Berlin with 22 recorded years were used to carry out runoff simulations. First of all, a rainfall statistical analysis was performed with the measured rainfall data in order to determine the annual rainfall durations, depths and frequencies in relation to the average rain intensity. The annual overflow data from overflow structures (overflow weirs and overflow basins) of not prerelieved drainage areas were computed by means of a simplified runoff model. The so determined overflow data is considerably lower than the data of rainfall analysis. Hence, overflow data from overflow structures in combined sewer systems wouldn't be satisfying if they are derived from only statistical rainfall analysis. Recorded rainfall events should rather be transformed into runoff events and accordingly analysed. As there were only 5 rain gaging stations available, a generalization of the computed overflow data is still impossible. However, these overflow data seem to be on the whole plausible if compared with rainfall data which were performed in the past only during the summer months.

scholarly journals EI-Nino southern oscillation and rainfall varIation over Bangladesh

MAUSAM ◽  
2021 ◽  
Vol 47 (2) ◽  
pp. 157-162
Author(s):  
A. S. M. SABBIR AHMED ◽  
A. A. MUNIM ◽  
Q. N. BEGUM ◽  
A.M. Choudhury
Keyword(s):  
Southern Oscillation ◽  
Rainfall Data ◽  
Seasonal Rainfall ◽  
Annual Rainfall ◽  
Rainfall Analysis ◽  
Rainfall Variation ◽  
Climatic Regions

In the present study, an attempt has been made to examine the variations of rainfall over Bangladesh and to find possible correlation with EI-Nino/Southern Oscillation (ENSO). Four stations have been chosen from four different climatic regions of Bangladesh for this purpose, namely  Jessore, Dhaka. Barisal and Srimangal. The regions have been classified according to annual rainfall amounts. The rainfall data for forty three years, (1950-1992) have been analysed. The yearly mean rainfall shows a distinct negative decreasing tendency with the occurrence of ENSO.The seasonal rainfall analysis shows a somewhat better correlation.  

Statistical Methods of Storm Analysis

1984 ◽  
Vol 16 (8-9) ◽  
pp. 85-92 ◽  
Author(s):  
V D Vukmirović ◽  
J Ž Despotović
Keyword(s):  
Statistical Methods ◽  
High Intensity ◽  
System Analysis ◽  
Drainage System ◽  
Rainfall Data ◽  
Rainfall Analysis ◽  
Complex Information ◽  
Run Off

The purpose of this high intensity rainfall analysis is quantization of a rainfall phenomenon. Hereafter the statistical methods are presented but only the basis of these, also the application to some real rainfall data and finally the differences among those methods are discussed. The most important components of a calculation by different methods are presented by an example. The complex information concerning small duration high intensity rainfall is useful for both hydrologist and design engineer and also necessary for urban run-off calculations and drainage system analysis.

scholarly journals Rainfall Analysis of Vrishabhavathi Valley in Bengaluru Region

2019 ◽  
Vol 8 (4) ◽  
pp. 9287-9290
Keyword(s):  
Heavy Rainfall ◽  
Prediction Models ◽  
Rainfall Data ◽  
Annual Rainfall ◽  
Rapid Urbanization ◽  
Flood Prediction ◽  
Rainfall Analysis ◽  
North East ◽  
South West ◽  
South West Monsoon

Vrishabhavathi valley is a part of river Arkavathi. It covers parts of Bengaluru Urban and Ramanagara districts with an area of 381.46 sq. kms. Due to rapid urbanization in Bengaluru lot of pervious strata is converted into non-pervious concrete or asphalt surfaces. Rainfall is a major event, which is resulting flood in Bengaluru city. Recently observed heavy rainfall, rapid urbanization, encroachment of streams and water bodies are the major causes of flooding in Bengaluru. Disturbance to human activities and damages to properties has been observed in Vrishabhavathi valley region due to heavy rainfall especially in heavy rain events. Rainfall data analysis has been carried out statistically and graphically on Vrishabhavathi valley from 1970 to 2018. Rainfall analysis was made on converting daily rainfall data to monthly average data and seasonal analysis of rainfall has made for three different monsoon seasons Pre- monsoon, South- West and North- East monsoon, distribution and frequency of rainfall has been analyzed and results are represented graphically. From the annual rainfall study it is observed that less rainfall variations till 1990 and rainfall pattern seem to be increasing constantly from 1990’s onwards till 2018, particularly in the months of August, September and October. The rainfall contribution during south-west monsoon is almost equal to 50% of total annual rainfall. Rainfall analysis is essential to develop appropriate flood prediction models utilizing latest rainfall data collected (KSNDMC Telemetric station data) and available geospatial data to address the issues of urban flood observed in many locations in Vrishabhavathi valley region and in Bengaluru.

Flooding in Jamaica with assessment of riverine inundation of Port Maria, St Mary

2013 ◽  
Vol 184 (1-2) ◽  
pp. 165-170 ◽  
Author(s):  
Arpita Mandal ◽  
Anuradha Maharaj
Keyword(s):  
Extreme Rainfall ◽  
Curve Number ◽  
Flood Plain ◽  
Coastal Areas ◽  
Rainfall Data ◽  
Annual Rainfall ◽  
Small Island ◽  
Extreme Rainfall Event ◽  
Ungauged Catchments ◽  
Run Off

Abstract Flash flooding, from extreme rainfall is one of the major natural disasters affecting Jamaica and other small island states of the Caribbean. Flooding in Jamaica is mainly riverine, coastal and depression with the major coastal towns being affected owing to their location on low lying areas. Such localization is driven by increase in urbanization and tourism along the coastal areas. The present work aims in a broad discussion of the flooding in Jamaica with special reference to riverine flooding of Port Maria, the capital of St Mary, one of the parishes lying in the high rain zone of the island and being affected by repeated events of flooding. Analysis of the extreme rainfall event of November 23rd–24th, 2006 shows that it exceeded the 30 yr annual rainfall of the area and the 100 yr return period as calculated from 30 yr annual rainfall data for the island. The Port Maria river lacks a gauging station to monitor flow data and flood discharge peaks. Several methods are used to calculate the run-off in such small ungauged catchments. In this study the Soil Conservation Systems Curve Number (CN) method was used to calculate the run-off from the measured rainfall data using empirical equations. Results show an unprecedented high of 13–14 inches affecting the buildings and other infrastructures, leading to the collapse of a newly constructed bridge over the river Port Maria. The town continues to get flooded from intense short duration rainfall continuing to affect life and property. Flood plain maps exist for the larger watersheds of the island but smaller yet flood prone ones have not been mapped so far. Hence this becomes very important to create a floodplain map showing the extent of the runoff from rainfall with respect to the buildings and other infrastructures of the area. The present work thus aims in creating a spatial distribution map of the runoff from the rainfall measurements aiding in developing a no build zone for this and for other low lying coastal areas of the island.

scholarly journals Long term rainfall trend over meteorological sub divisions and districts of India

MAUSAM ◽  
2021 ◽  
Vol 68 (3) ◽  
pp. 439-450
Author(s):  
SURINDER KAUR ◽  
SUMANT KUMAR DIWAKAR ◽  
ASHOK KUMAR DAS
Keyword(s):  
Uttar Pradesh ◽  
Kendall Test ◽  
Rainfall Data ◽  
Annual Rainfall ◽  
Positive Trend ◽  
Rainfall Analysis ◽  
Increasing Trend ◽  
Long Term Trend ◽  
Agriculture Water

In this paper the long term trend of annual and seasonal rainfall over different districts, Meteorological (Met.) sub-divisions and whole India have been studied using the long term rainfall data for the period from 1901 to 2013. The changes in amount and pattern of rainfall have a significant impact on agriculture, water resources management and overall economy of the country. Mann-Kendall test is applied to check the significance of the trend. Linear Regression and Theil-Sen’s non parametric test has been applied to estimate the trend. The study is carried out for 632 districts and 34 sub divisions of India by utilizing the gridded rainfall data (0.25° × 0.25°) over the main land except Andaman & Nicobar and Lakshadweep islands. Many authors have studied that extreme events are increasing but there is no trend in Pan India’s rainfall. It is observed from the annual rainfall analysis 10% of the number of districts are showing significant increasing trend and 13% significant decreasing (mainly in Uttar Pradesh) trend whereas irrespective of high and low rainfall regions, 10% area of the country is showing significant increasing trend and 8% of the area of the country showing significant decreasing trend in annual rainfall. In Meteorological Sub divisions, east & west UP are showing significant negative trend and some of the coastal sub divisions are showing positive trend. It is also observed that the country’s rainfall is not showing any trend.

scholarly journals Statistical analysis of seasonal rainfall data in Chandigarh: A case study

2021 ◽  
Vol 889 (1) ◽  
pp. 012024
Author(s):  
Kaamun ◽  
Sahil Arora
Keyword(s):  
Statistical Analysis ◽  
Goodness Of Fit ◽  
Seasonal Forecast ◽  
Rainfall Data ◽  
Seasonal Rainfall ◽  
Annual Rainfall ◽  
Maximum Rainfall ◽  
The Past

Abstract The following research focuses on Chandigarh’s annual rainfall of past 50 years i.e. from 1968 to 2017. Parameters like Kurtosis, Variance, Goodness of Fit, Mann-Kendall’s Test were performed along with total annual forecast as well as seasonal forecast was predicted. Seasonal rend was also studied so as to study in detail about the past, present, and future of rainfall in Chandigarh. This study was performed with the help of MS-Excel and ExcelStat. A rising trend was found in Chandigarh for total as well as seasonal rainfall with a maximum rainfall of 1510.9 mm in the year of 1996 and a minimum of 371.1 mm in year 1987, other than this Sen.’s slope was 6.431 whereas skewness was found to be 0.6018.

Infectious rain? Evaluation of human pathogen concentrations in stormwater in separate sewer systems

2019 ◽  
Vol 80 (6) ◽  
pp. 1022-1030 ◽  
Author(s):  
Christiane Schreiber ◽  
Sophie-Bo Heinkel ◽  
Nicole Zacharias ◽  
Franz-Michael Mertens ◽  
Ekkehard Christoffels ◽  
...  
Keyword(s):  
River System ◽  
Traffic Load ◽  
Human Pathogens ◽  
Residential Areas ◽  
Sewer System ◽  
Sewer Systems ◽  
Run Off ◽  
Combined Sewer ◽  
High Concentrations ◽  
The Eu

Abstract Separate sewer systems collect and discharge rainwater directly into surface water bodies. In residential areas covering moderate traffic load these are alternative drainage routes to avoid combined sewer overflow discharge and to keep rivers clean as required by the EU Water Framework Directive. This overflow's microbial quality, however, needs to be evaluated, since stormwater run-offs are potential pathways for pathogens into river systems. Between 2010 and 2016, two separate sewer systems in North Rhine-Westphalia (Germany) were investigated. The stormwater outflow was sampled during discharge events and microbiologically analysed. The results showed high concentrations of Escherichia coli (1,100–1,100,000 CFU/100 mL) and Clostridium perfringens (20–13,000 CFU/100 mL). Campylobacter and Salmonella were detected in 97% and 43% of the samples. Giardia cysts were more often detected (31.6%) than Cryptosporidium oocysts (10.5%). The sources of human pathogens in rainwater run-off are heterogeneous. While roads have already been declared as chemical polluters via rainwater run-off, our study detected supplementary pollution of mainly faecal microorganisms. Presumably, failed connections in the sewer system itself are important sources of human pathogens. We suggest treatment of stormwater run-offs before being discharged into the river system.

scholarly journals Changes in rainfall patterns on the upper Ecuadorian Andean mountains: Analysis of extreme precipitation, ENSO effects and shifts of annual rainfall variation

2020 ◽  
Vol 11 (3) ◽  
Author(s):  
Paulina Rosana Lima Guamán ◽  
Jorge Luis Santamaría Carrera ◽  
Margarita Flor
Keyword(s):  
Water Resources ◽  
Water Resource ◽  
Extreme Precipitation ◽  
Annual Rainfall ◽  
Rainfall Runoff ◽  
Rainfall Variation ◽  
Runoff Variation ◽  
Extreme Precipitation Events ◽  
And Shifts ◽  
Precipitation Events

Rainfall in the upstream drainage area of the Ecuadorian Andean Mountains (EAM) is an important source of water supply in populated areas. Managing water resource projects depend on rainfall-runoff variation. Even though, it is difficult to understand the mechanism that controls rainfall variation because of the influence of several global and local hydrological processes, this type of research is needed to improve the management of water resources. Understanding these processes is complex due to inaccessibility to these remote zones leading to inefficacy in the monitoring of these gauge stations. Furthermore, there are reports that exposed that climatic anomalies are affecting rainfall-runoff processes around the world. These climate changes cause two main problems in urban infrastructure. First, the occurrence of extreme precipitation events increasing the risk of flooding. Second, changes on annual rainfall variation that could lead to water scarcity in the management of water resource projects. This study focuses on improving the understanding of rainfall trends at EAM and its implications in the management of water resources. The results indicate that 71% of extreme precipitation events were registered in the second period of the last twenty years (1995 – 2015) with severe short rainfall events, during ENSO years in the EAM, threatening hydraulic facilities.

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