{"type":"script","doc_desc":{"producers":[{"name":"Reproducibility WBG","abbr":"DECDI","affiliation":"World Bank - Development Impact Department","role":"Verification and preparation of metadata"}],"prod_date":"2025-10-13","version":"1"},"project_desc":{"authoring_entity":[{"name":"Bramka Arga Jafino","affiliation":"The World Bank","email":"bjafino@worldbank.org"},{"name":"Ruben Jongejan","affiliation":"The World Bank","email":"ruben.jongejan@jongejanrmc.com"},{"name":"Mathijs van Ledden","affiliation":"The World Bank","email":"mvanledden@worldbank.org"},{"name":"Kasper Lendering","affiliation":"The World Bank","email":"kasper@awa-consult.com"},{"name":"Jasper Verschuur","affiliation":"Delft University of Technology","email":"j.verschuur@tudelft.nl"},{"name":"Debashish Paul Shuvra","affiliation":"The World Bank","email":"dshuvra@worldbank.org"},{"name":"Swarna Kazi","affiliation":"The World Bank","email":"skazi1@worldbank.org"}],"title_statement":{"title":"Reproducibility package for An Exploration Of System-Wide Flood Protection Standards For Coastal Polders In Bangladesh","idno":"RR_BGD_2025_442"},"data_statement":"Some data is restricted and has not been included in the reproducibility package. For more details, please refer to the individual data entries and the README file. ","software":[{"name":"Python","version":"3.9.23"}],"scripts":[{"title":"Reproducibility package for An Exploration Of System-Wide Flood Protection Standards For Coastal Polders In Bangladesh","date":"2025-10","notes":"Computational reproducibility verified by Development Impact (DECDI) Analytics team, World Bank.","instructions":"See README in reproducibility package.","file_name":"RR_BGD_2025_442","zip_package":"RR_BGD_2025_442.zip"}],"repository_uri":[{"name":"Reproducible Research Repository (World Bank)","uri":"https:\/\/reproducibility.worldbank.org"}],"production_date":"2025-10-13","abstract":"Bangladesh has demonstrated how investments in coastal flood protection save lives, reduce economic losses, and protect development gains. Yet, its cost effectiveness depends on the design standards, which are currently selected on a project-by-project basis. This is because at present, there is no law, policy or agency guidance to guide or inform decisions on design standards for coastal polders in Bangladesh. To inform the discussion on appropriate flood protection standards for Bangladesh\u2019s coastal polders, this paper investigates what these standards would look like if they were based on cost-benefit analyses.  \n\nThis study finds that implementing differentiated flood protection standards across the coastal polders can be a cost-effective strategy for further suppressing flood risks, reducing up to 27.5% of the total cost and flood risks (i.e., from US$ 23.4 billion investment cost + US$ 11 billion flood risk to US$ 18.6 billion investment cost + US$ 6.7 billion flood risk). This includes the substantial investment in bank protection needed (~US$5 billion), irrespective of the flood protection standards, to maintain the alignment of the present embankments around the coastal polders. Areas like Khulna (with significant economic activity and natural cyclone buffering from the Sundarbans) stand out as candidates for extra-high protection, because the cost to elevate defenses is relatively low while the benefits are substantial. While the absolute values of the economically optimal protection levels are subject to considerable uncertainty, a sensitivity analysis confirms the robustness of the finding that there is considerable value in flood protection level differentiation. \n\nFlood protection standards are rarely based on economic considerations alone. They could also be informed by the desire to reduce life safety risk or combat poverty. It is recommended that the implications of applying different perspectives on the tolerability of risks to determine differentiated flood protection standards are carefully explored in consultation with stakeholders.  ","geographic_units":[{"name":"Bangladesh","code":"BGD"}],"keywords":[{"name":"Flood Protection"},{"name":"Resilience"},{"name":"Disaster Risk Management"},{"name":"Optimization"},{"name":"Infrastructure Planning"}],"topics":[{"id":"Q54","uri":"https:\/\/www.aeaweb.org\/econlit\/jelCodes.php?view=jel","vocabulary":"Journal of Economic Literature (JEL)","name":"Climate \u2022 Natural Disasters and Their Management \u2022 Global Warming","parent_id":"Q5"},{"id":" O18","uri":"https:\/\/www.aeaweb.org\/econlit\/jelCodes.php?view=jel","vocabulary":"Journal of Economic Literature (JEL)","name":"Urban, Rural, Regional, and Transportation Analysis \u2022 Housing \u2022 Infrastructure","parent_id":"O1"},{"id":" O21","uri":"https:\/\/www.aeaweb.org\/econlit\/jelCodes.php?view=jel","vocabulary":"Journal of Economic Literature (JEL)","name":"Planning Models \u2022 Planning Policy","parent_id":"O2"},{"id":" O10","uri":"https:\/\/www.aeaweb.org\/econlit\/jelCodes.php?view=jel","vocabulary":"Journal of Economic Literature (JEL)","name":"General","parent_id":"O1"}],"output":[{"type":"Working Paper","description":"Policy Research Working Papers (PRWP)","title":"An Exploration Of System-Wide Flood Protection Standards For Coastal Polders In Bangladesh"}],"language":[{"name":"English","code":"EN"}],"disclaimer":"The materials in the reproducibility packages are distributed as they were prepared by the staff of the International Bank for Reconstruction and Development\/The World Bank. The findings, interpretations, and conclusions expressed in this event do not necessarily reflect the views of the World Bank, the Executive Directors of the World Bank, or the governments they represent. The World Bank does not guarantee the accuracy of the materials included in the reproducibility package.","license":[{"name":"Modified BSD3","uri":"https:\/\/opensource.org\/license\/bsd-3-clause\/"}],"contacts":[{"name":"Bramka Arga Jafino","affiliation":"The World Bank","email":"bjafino@worldbank.org"},{"name":"Reproducibility WBG","affiliation":"The World Bank","email":"reproducibility@worldbank.org"}],"datasets":[{"name":"Coastal Adaptation Risk Data","note":"Files location: Input\/Risk_summary_polder.csv. \nThe raw input data is collected from two unpublished datasets: (i) Polder-level present and future risk estimates per impact category from Verschuur et al. (2023) and (ii) the 'Cost of Coastal Adaptation Tool' developed by TU Delft (2020). Interested readers may contact Swarna Kazi (skazi1@worldbank.org), Bramka Arga Jafino (bjafino@worldbank.org), or Jasper Verschuur (j.verschuur@tudelft.nl) to inquire about data.","access_type":"The data is restricted and not included in the reproducibility package. ","citation":"Verschuur, J., Jafino, B. A., & Kazi, S. (2025). Polder-level present and future risk estimates and Cost of Coastal Adaptation Tool outputs [dataset]. Delft University of Technology & World Bank.","uri":"https:\/\/datacatalog.worldbank.org\/int\/data\/dataset\/0066919\/flood_risk_summary_of_bangladesh_coastal_polders"},{"name":"Bangladesh Coastal Zone Boundaries","uri":"https:\/\/geodata.ucdavis.edu\/gadm\/gadm4.1\/gpkg\/gadm41_BGD.gpkg","access_type":"Data is publicly available, but does not allow redistribution, and it is not included in the reproducibility package.","note":"Files location: Input\/coastalzone.gpkg. Geopackage of the Bangladesh coastal zone, containing ADM2 districts used in the analysis. \nThe authors used the ADM_ADM_2 layer and manually retained only the following districts: Bagerhat, Barguna, Barisal, Bhola, Chandpur, Chittagong, Cox\u2019s Bazar, Feni, Gopalganj, Jessore, Jhalokati, Khulna, Lakshmipur, Narail, Noakhali, Patuakhali, Pirojpur, Satkhira, and Shariatpur. All other districts were removed using QGIS.  ","license_uri":"https:\/\/gadm.org\/license.html","license":"GADM license","citation":"GADM. (2023). GADM v4.1: Bangladesh (GPKG) [dataset]. University of California, Davis. Available at https:\/\/geodata.ucdavis.edu\/gadm\/gadm4.1\/gpkg\/gadm41_BGD.gpkg"},{"name":"Flood risk summary of Bangladesh coastal polders","uri":"https:\/\/datacatalog.worldbank.org\/int\/data\/dataset\/0066919\/flood_risk_summary_of_bangladesh_coastal_polders","note":"Geopackage containing information on coastal polders in Bangladesh. \nFiles location: Input\/polders_file.gpkg. The base shapefile is publicly accessible from the BWDB GIS portal (https:\/\/gis.bwdb.gov.bd\/arcgis\/apps\/webappviewer\/index.html?id=38d89295444d46578cbce6d534b0d17f), but additional variables were manually merged from the 'Cost of Coastal Adaptation Tool' (TU Delft, 2020), including: T, 10, 25, 100, Dec. Height [m], b-value, Average elevation (mPWD), a-value, h0-value, and embankment_height. \nFurther, five variables (coastaldyke, riverdyke, slope protection coastal, slope protection river, and bank protection) were added through expert inference by Jasper Verschuur and Kasper Lendering. Interested readers may contact Swarna Kazi (skazi1@worldbank.org), Bramka Arga Jafino (bjafino@worldbank.org), or Jasper Verschuur (j.verschuur@tudelft.nl) to inquire about data.","access_type":"The data is restricted and not included in the reproducibility package. ","citation":"Verschuur, J., Jafino, B. A., & Kazi, S. (2025). Polder-level present and future risk estimates and Cost of Coastal Adaptation Tool outputs [dataset]. Delft University of Technology & World Bank."}],"reproduction_instructions":"To reproduce the results, a new user should:\n\n1. Recreate the environment using the `environment.yml` file.\n2. Open the notebook `Optimal_polder_protection_clean.ipynb`.\n3. Run the notebook.\n\nThe data used in this paper is currently restricted. It is available in the Development Data Hub (DDH) under a restricted-access license. Therefore, the Jupyter notebook executed by the replicators, along with the generated outputs, is included in the reproducibility package so users can compare the reproduced results with those in the paper.\n\n","technology_requirements":"Runtime: 10 hours","technology_environment":"*Note: The following specifications reflect the environment used by the replicator. They may differ from the technical specifications listed in the authors\u2019 README file, which correspond to the authors\u2019 own computing environment.*\nPaper exhibits were reproduced on a computer with the following specifications:\n\u2022 OS: macOS Sequuoia\n\u2022 Processor: Apple M4 Pro\n\u2022 Memory available: 24 GB"},"tags":[{"tag":"DOI"},{"tag":"Open Code"},{"tag":"Restricted Data"}],"schematype":"script"}