analysis and synthesis of data about floods in alexandra analysis and synthesis of data about floods in alexandra

/CreationDate (D:20070302092647) [Links], SMITHERS JC and SCHULZE RE (2000a) Development and evaluation of techniques for estimating short duration design rainfall in South Africa. The city is even planning to help some residents pay to flood-proof their houses, since bigger drainage projects will take years to complete. >> Some bridges may have one side that is lower than the other. ", King is not surprised by NPR's findings that residents of Southbridge are getting a worse deal on flood insurance compared with residents of wealthier, whiter parts of the state. Abstract. Flood depth grids or raster files contain a flood depth value within each cell in the raster. endobj Flood depth at a given point can help determine the impact to buildings, roads, or bridges. [Links], VAN BLADEREN D (1993) Application of historical flood data in flood frequency analysis, for the Natal and Transkei region. Are you sure you have typed the correct hostname? Models of data from the mapped areas with high risk of flooding will be possible for quantitative predictions of floods, such as forecasts of local water levels; [13] Analysis and Synthesis of Data Analysis and Synthesis of Data 68. It is recommended that the limitations of available flow records to estimate extreme flow events need to be urgently addressed. Stay safe and keep a safe following distance when driving., #flooding Region E Officers monitoring rising water levels along the Jukskei river near Setswetla Informal settlement, Alexandra pic.twitter.com/gT8H0u2Txq, City of Joburg EMS (@CityofJoburgEMS) February 8, 2020, Motorists are advised to avoid the Buccleuch Dr Bridge, due to flooding of Jukskei River. Stream flow-gauges located in KZN were selected for inclusion in the analysis based on the attributes of the gauges. Discontinuities at regional boundaries need to be investigated and the alternative approach of transferring hydrological information from gauged to ungauged sites within a region should be evaluated. /Rotate 0 Trigg says all but one of the families on his block left. A digital terrain model (DTM) raster can be added to the 3D scene to provide a realistic scene for illustrating the impact of the flood. Per- pass analysis of acute ischemic stroke clots: impact of stroke etiology on extracted clot area and histological composition - Journal of Distribution Future Energy Scenarios: Regional Review - South West licence area westernpower.co.uk - Western Power AREA II AREA II / RCRCA - Area II MN River Basin. 8. But the financial calculus there is different, because homeowners can afford flood insurance at least up to a point. Effective flood response planning begins with a better understanding of the potential flood impact. 339 0 obj <>/Filter/FlateDecode/ID[<89E9D5212B1D2248BF238A2327DBA6A1>]/Index[317 43]/Info 316 0 R/Length 109/Prev 157782/Root 318 0 R/Size 360/Type/XRef/W[1 3 1]>>stream endstream endobj 103 0 obj <>/Encoding<>>>>> endobj 65 0 obj <> endobj 66 0 obj <> endobj 146 0 obj <> endobj 20 0 obj <> endobj 25 0 obj <> endobj 156 0 obj <> endobj 147 0 obj <> endobj 137 0 obj <> endobj 133 0 obj <> endobj 127 0 obj <> endobj 107 0 obj <> endobj 126 0 obj <>stream These workflows include preparing the data for analysis, defining the flood impact area and the impact on infrastructure, facilities and buildings, sharing the flood impact information, visualizing the flood impact in 3D, and sharing the impact in 3D. 1420/3/07. The flooded roads can be an impediment to successful evacuations for first responders and community members when it is unknown which roads will be impacted. The Flood Impact Analysis ArcGIS Pro project includes a series of tasks to help guide you through the workflows below. endobj /Font 42 0 R Before the flood, Aaron Trigg says, there were baseball games and kids playing on the playground near his house in Rainelle. The result can be used to identify watch points for observers to report flood depth during the flooding event. xWnF}W\p{Ns[}PeGMr%j!3CTu~Xm'[?Wr8Ov]Wcj)y]% QKoszTM*WTyj#7 Sp9\1'TsF(qQr*rlPE9WVtoWn%kkrJ9q5r#([IDN`m<9XL5 ^b3{0a^5OY#ryF&OwH(IP`V{%HIr|q7:wct{,5 %PDF-1.5 % After the initial selection of gauges, additional gauges with 15-20 years of record were investigated for inclusion in the analysis in areas which did not have any gauges included in the initial selection. We believe in strength of global idea sharing and the power of education, so we work and develop the ReadkonG to help people all over the world to find the answers and share the ideas they are interested in. Using design to make life better for people. To conduct the flood impact analysis, complete the following steps: Accurate analysis and visualization of the flood impact analysis will depend on several factors such as: availability of flood depth data in the form of raster, ground elevation data such as Digital Terrain Model (DTM) or lidar, and features describing the assets to be analyzed such as roads, bridges, and buildings. /Font 24 0 R This includes preliminary data analysis (data screening and outlier analysis), sensitivity analysis, identification of homogenous regions and suitable regional distribution models for the %PDF-1.6 % A limitation of using a single-site approach to flood frequency analysis is that relatively few gauging stations in South Africa have long record lengths (e.g. Ryan Kellman/NPR /Count 9 >> After screening of the data, only 122 stations were included in further analyses (Fig. >> Share the scene with your colleagues to help them understand the impact of local flooding on your community. "Not so much for myself, but for the people I could hear. As part of the development of the Joint Peak-Volume (JPV) methodology, Grgens (2007) developed a regionalised index flood approach to design flood estimation for South Africa. "The end result is that low valued homes are paying too much, and high valued homes are paying too little," she says. Flooding possible in parts of the Free State, Gauteng, North West, northern KZN and western Mpumalanga. A narrative synthesis can provide a first step in looking systematically at, and organising, the data. "Now, it was just silence," he remembers. These data are drawn from various sources including newspaper clippings, community- based records, data from the Red To create a water surface elevation raster, extract flooded areas, and crate the water surface elevation input geodatabase, follow the steps in the Prepare water surface elevation raster task. << The following sections provide a brief background to the RFFA methods used in this study. Here, flood insurance is already unaffordable for many residents, and climate-driven flood damage has already exceeded local resources. The tool will use your water depth geodatabase and the specified risk type to calculate the flood depth exposure to each building within the flood impact area. The catchment descriptors (Desi) included catchment area, equal area catchment slope, MAR90, and an index of the veld type zone or K-region. Third quarter 2019 conference call - November 1, 2019 - TC Energy. NsuAA} & Kukulka, T. (2003). Congress has considered such changes, as well as new requirements that flood risk be disclosed to homeowners and renters before they move in. June 12, 2022 . The new data show that flood insurance rates would need to more than quadruple to keep up with the costs of climate-driven flooding. WRC Report No. WRC Report No. Follow the steps in this task to learn how to use the Flood Impact Analysis solution. The poor performance of the JPV method with the regionalised LP3 distribution needs to be investigated. Likes trains and dogs and women's footy. The reliability of design values estimated from the observed data is dependent on the quality of the observed data and length of available record. /Parent 2 0 R /Resources << 10 0 obj FEMA's changes could also help reverse a decades-long trend of overdevelopment in floodplains. /ExtGState 26 0 R The frequency with which recorded flow stages exceed the maximum rated level needs to be quantified and the impact of not including these extreme events in the estimation of design floods in South Africa must be quantified. /Keywords () Based on the results in Table 1 and the typical results shown in Fig. 16 0 obj Use this task to share the depth elevation raster that was created previously to help improve the visualization of the 3D scene. Meanwhile, sea level rise and wetter, more-powerful hurricanes are threatening coastal towns. Hydrol. When large numbers of people don't have insurance or savings after a disaster, the effects can ripple through the community. /Height 64 5 0 obj The results from this study are applicable only to KZN and the performance of the various RFFA methods at a national scale needs to be investigated. /Font 14 0 R t_dn\\EfWoymJUYVl"ApGj{s,vkY"SVxgdNg-yn#]2AT2pfhAQ{y]=^ :a iF?My.iziHoAy%Fs0#~nh,Z. As summarised by Smithers (2012), many studies have shown that RFFA will result in more accurate and consistent estimates than at-site analyses (e.g. Equation 1 was used to estimate the MAF at ungauged sites (Mkhandi et al., 2000). 7 0 obj Analysis Techniques: Flood Frequency Analysis Example with Instantaneous Peak Data from Streamflow Evaluations for . Performance of regional flood frequency analysis methods in KwaZulu-Natal, South Africa, JC SmithersI, II, *; J StreatfieldII; RP GrayII; EGM OakesII, IBioresources Engineering, School of Engineering, University of KwaZulu-Natal, Private Bag X01, Scottsville, 3209, South Africa IIJeffares & Green (Pty) Ltd, 6 Pin Oak Avenue, Hilton, Pietermaritzburg, 3201, South Africa. /MediaBox [0 0 595 842] But for residents of the historically Black neighborhood of Southbridge in Wilmington, Del., it's a different story. As the cost of insurance goes up, many people who need flood insurance will likely be unable to afford it, leaving them to face lasting damage. e-mail: Smithers@ukzn.ac.za, All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License. Overhauling the National Flood Insurance Program could offer some relief to towns like Rainelle. /Rotate 0 10. 2) with 92 stations from South Africa, of which 8 stations were used for independent testing of the method. [Links], SMITHERS JC (2012) Review of methods for design flood estimation in South Africa. Use this task to choose which flood impact layers to share, such as the flood impact area, impacted roads, bridges, and buildings for each flood scenario. /MediaBox [0 0 595 842] This approach is known as regional flood frequency analysis (RFFA) and utilises data from several sites to estimate the frequency distribution of floods at each site. streams discussed herein, is the use of consistent methods for data synthesis, . This task is designed to step through a standardized process to create and analyze the impact of each flood scenario on your community. /Resources << This task requires that you have a water surface elevation (WSE) geodatabase as described in the Prepare flood depth and elevation data task. /Creator (deskPDF 2.55) You will assume the role of a mapping technician responsible for analyzing the potential flood impact for your community. /Rotate 0 Data from 74 flow gauging stations and inflows to dams were used in the regionalisation, with the distribution of stations as shown in Fig. /Contents 37 0 R This task allows you to create 3D flood levels from raster input data. [Links], STEDINGER JR, VOGEL RM and FOUFOULA-GEORGIOU E (1993) Frequency analysis of extreme events. Visualization of 3D flood levels is more powerful when shown together with other 3D layers such as 3D buildings, 3D trees, and detailed elevation. (2000), Haile (2011) and Grgens (2007) encompass the whole of South Africa. Flooding is a common hazard in Nezahualcoyotl, a Mexican city just outside the nation's capital. Brittany Patterson contributed reporting from West Virginia. /ProcSet [/PDF /Text] The result is a 3D version of the 2D raster data. While the Haile method resulted in the smallest MAREM,D value, the average slope of the estimated vs. observed floods is considerably less than 1, indicating that the Haile method generally underestimates the floods computed from the observed data. Use the Create depth elevation raster task to create the depth elevation raster. More than 4 million houses and small apartment buildings across the contiguous U.S. have substantial risk of expensive flood damage, according to data released by the First Street Foundation, a nonprofit research organization that studies flood risk and housing. /Type /Page endobj The town is a bellwether for a future in which flood insurance is increasingly unaffordable and climate-driven flood damage exceeds local resources in many places. "It's shocking," says John Wyatt, a member of the Rainelle City Council. As shown in Fig. The method developed by Van Bladeren (1993) is applicable for RMF Regions 5.0 to 5.6 in Natal and Transkei. It offers a broad range of benefits, which are . 681/1/00. /ProcSet [/PDF /Text] The planning stages were survey, data inventory, data analysis, synthesis, and riverscape concept. He is confident that the city's plan will lead to significantly less flooding. You can also symbolize the impacted roads for each flood impact area. 71 0 obj <> endobj 68 0 obj <>stream Touring the world with friends one mile and pub at a time You will assume the role of a mapping technician responsible for creating the flood impact analysis and sharing the results with emergency management, public works, and planning agencies. hide caption. Research Report RC 15658. As shown in Fig. [Links], VAN DER SPUY D and RADEMEYER PF (2010) Flood Frequency Estimation Methods as Applied in the Department of Water Affairs. Water surface elevation data can be used to calculate bridge heights above flood stages and to visualize the flood stages as 3D surfaces. >> Practitioners in South Africa generally estimate design floods by performing a frequency analysis of gauged flow data at a given location, if flow data are available at the site of interest, or by using an event-based rainfall-runoff model, for example, using the rational method, unit hydrograph method, or Soil Conservation Services method adapted for conditions in South Africa (SCS-SA). A survey undertaken by Campbell et al. Water Research Commission, Pretoria. If you still need help you can always visit the WordPress Support Forums. /Font 36 0 R The criteria used were length of record, with gauges included for record lengths > 20 years, start and end date of flow record, the percentage of values in the AMS where the recorded stage exceeded the limits of the rating curve for the flow-gauging station, the number of values in the AMS which were flagged as having missing data during the year, and the period of the year when the missing data occurred. hide caption. Hence, the need for consistent screening and checking of the flow data is required in order to identify reliable data records that can be used for design flood estimation. NPR also found that homeowners who are getting a better deal on flood insurance live in whiter neighborhoods. [Links], MIDGLEY DC, PITMAN WV and MIDDLETON BJ (1994) Surface water resources of South Africa 1990. Jay, D. A. The 3D web scene can be shared with stakeholders who are responsible for flood response planning and flood mitigation planning. The Flood Impact Analysis project includes a task workflow that provides a structured sequence using tasks and steps. However, limitations of event-based methods include the assumption that the exceedance probability of the flood event is the same as the exceedance probability of the rainfall event, i.e., the 100-year return period flood event is assumed to result from a 100-year return period rainfall event, and the antecedent soil moisture condition in the catchment prior to extreme rainfall events is not taken into account. A description for each task in this group is listed below. 10 also confirm the poor performance of the JPV method when the regionalised LP3 distribution is used. *@V4YH|@Mn C|I@6'yg The Flood Impact Analysis ArcGIS Pro project includes a series of tasks to help guide you through these workflows. endobj Ryan Kellman/NPR Those places include wealthy neighborhoods in Sarasota, Fla., Charleston, S.C., and exclusive suburbs of Chicago, Houston, Los Angeles and New York. >> << President Biden has said that helping Americans adapt to a hotter Earth in an equitable way is one of his priorities. /ColorSpace /DeviceRGB After the flood, that changed. /Type /XObject Water SA 38 (4) 633-646. 317 0 obj <> endobj /Type /Page Van Bladeren (1993) derived growth curves using both continuously recorded data and discharges derived from historical flood information from the Natal and Transkei regions. If anything, residents are slightly overpaying. /MediaBox [0 0 595 842] Four and a half years later and we still have so many buildings in town that are just destroyed." IBM Research Division, Yorktown Heights, New York, USA. Charles Sauriol Conservation Area Salmon Run. /Rotate 0 In: Parker DJ (ed.) And new data make it clear that many households and communities cannot afford the mounting costs. 356 pp. Once the analysis is completed, share the results with community stakeholders who can use the information to begin flood response or mitigation planning. /ProcSet [/PDF /Text] Mkhandi et al. The result of this study was the basic concepts of ecotourism development, which were realized in . "It's just inequitable, and it's hurting the people who need the insurance the most by charging them way too much," flood expert Carolyn Kousky says. This task allows you to analyze impacted roads by calculating depth of flooding for each road segment for any number of flood levels. mqplHj-&t NP{(pJ mkA|$ rT5(dm2KIb H[g![a>-9ANe7N?v7AN6&-0+2j}E{L 4 0 obj 00vtt0h 1sFGGgqt0v` bLEBD^`-@B`SC:w;8? The Pearson Type 3 (P3) distribution fitted by probability weighted moments (PWM) was found to be the best distribution in all regions in South Africa, with the exception of SAF13 where the Log-Pearson Type 3 (LP3) distribution fitted by the Method of Moments (MM) was used. J. 2007-11-01T21:39:30-07:00 As it got dark, he could hear people screaming for help. /ProcSet [/PDF /Text] "A lot of people in Rainelle were poor, and they didn't have any insurance. hbbd```b``SA$Sdfe ed7?d+XnA$We R $xNc yE` A critical aspect of RFFA is the identification of relatively homogenous flood response regions. << This general underestimation by the Haile method is confirmed by the performance of the RFFA methods in estimating the 50-year return period floods shown in Fig. /ProcSet [/PDF /Text] tj -H330\H20B1 A where: MAF = mean annual flood (m3s-1), CONSTANT = regionalised parameter, AREA = catchment area (km2), and EXPONENT = regionalised parameter. 9, 67.4% of the gauges in KZN had a single unique maximum value in the AMS, whereas 15.7% of the gauges had the same maximum value in more than 20% of the years, which is an indication that the rating table used to convert the observed river stage into discharge had been exceeded. /Rotate 0 He's running for mayor, and he imagines Rainelle hosting an Appalachian music festival and attracting hiking tourists. 45 (3) 449-464. With no money for repairs, many people took what they could salvage and left Rainelle for good. ln(Index Flood Peak) = Bo + B1 ln(Des1) + B2 ln(Des2) + B3 ln(Des3) + .(3).