{"id":20027388,"url":"https://github.com/huidaecho/mefa","last_synced_at":"2025-05-05T02:31:32.559Z","repository":{"id":138941530,"uuid":"608015034","full_name":"HuidaeCho/mefa","owner":"HuidaeCho","description":"Memory-Efficient Flow Accumulation (MEFA)","archived":false,"fork":false,"pushed_at":"2025-03-07T03:55:54.000Z","size":135,"stargazers_count":6,"open_issues_count":0,"forks_count":1,"subscribers_count":1,"default_branch":"master","last_synced_at":"2025-04-08T15:49:47.771Z","etag":null,"topics":[],"latest_commit_sha":null,"homepage":"","language":"C","has_issues":true,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":null,"license":"gpl-3.0","status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/HuidaeCho.png","metadata":{"files":{"readme":"README.md","changelog":null,"contributing":null,"funding":null,"license":"COPYING","code_of_conduct":null,"threat_model":null,"audit":null,"citation":null,"codeowners":null,"security":null,"support":null,"governance":null,"roadmap":null,"authors":null,"dei":null,"publiccode":null,"codemeta":null}},"created_at":"2023-03-01T06:16:38.000Z","updated_at":"2025-03-07T03:55:58.000Z","dependencies_parsed_at":null,"dependency_job_id":"a4f4bf92-41cd-4fa6-acc0-d163de4848a0","html_url":"https://github.com/HuidaeCho/mefa","commit_stats":null,"previous_names":["huidaecho/mefa"],"tags_count":0,"template":false,"template_full_name":null,"repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/HuidaeCho%2Fmefa","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/HuidaeCho%2Fmefa/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/HuidaeCho%2Fmefa/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/HuidaeCho%2Fmefa/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/HuidaeCho","download_url":"https://codeload.github.com/HuidaeCho/mefa/tar.gz/refs/heads/master","host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":252427886,"owners_count":21746293,"icon_url":"https://github.com/github.png","version":null,"created_at":"2022-05-30T11:31:42.601Z","updated_at":"2022-07-04T15:15:14.044Z","host_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub","repositories_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories","repository_names_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repository_names","owners_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners"}},"keywords":[],"created_at":"2024-11-13T09:10:06.362Z","updated_at":"2025-05-05T02:31:32.550Z","avatar_url":"https://github.com/HuidaeCho.png","language":"C","funding_links":[],"categories":[],"sub_categories":[],"readme":"# Memory-Efficient Flow Accumulation (MEFA)\n\nPart of the [Memory-Efficient I/O-Improved Drainage Analysis System (MIDAS)](https://github.com/HuidaeCho/midas)\n\nPlease cite [Cho (2023)](https://doi.org/10.1016/j.envsoft.2023.105771) when you use this algorithm or the [r.flowaccumulation](https://grass.osgeo.org/grass-stable/manuals/addons/r.flowaccumulation.html) [GRASS](https://grass.osgeo.org/) addon.\n\n**Citation**: Huidae Cho, July 2023. Memory-Efficient Flow Accumulation Using a Look-Around Approach and Its OpenMP Parallelization. Environmental Modelling \u0026 Software 167, 105771. [doi:10.1016/j.envsoft.2023.105771](https://doi.org/10.1016/j.envsoft.2023.105771). [Author's Version](https://idea.isnew.info/publications/Memory-efficient%20flow%20accumulation%20using%20a%20look-around%20approach%20and%20its%20OpenMP%20parallelization.pdf).\n\n![MEFA Graphical Abstract](https://idea.isnew.info/publications/Memory-efficient%20flow%20accumulation%20using%20a%20look-around%20approach%20and%20its%20OpenMP%20parallelization%20-%20Graphical%20abstract.png)\n\n* Raw data: 30-m NED for the entire Texas\n  * 1.8 billion cells including null\n  * 773 million cells without null\n* Red: MEFA\n* Blue and purple: Benchmark algorithms\n\nPredefined flow direction encodings in GeoTIFF: power2 (default, r.terraflow, ArcGIS), taudem (d8flowdir), 45degree (r.watershed), degree\u003cbr\u003e\n![image](https://github.com/user-attachments/assets/990f0530-fded-4ee5-bfbb-85056a50ca1c)\n![image](https://github.com/user-attachments/assets/a02dfc15-a825-4210-82c4-4c9296dafadc)\n![image](https://github.com/user-attachments/assets/64f5c65a-c7cc-4e06-a69f-6fccd6435426)\n![image](https://github.com/user-attachments/assets/fafef436-a5f2-464a-89a8-9f50a877932c)\n\nCustom flow direction encoding is also possible by passing `-e E,SE,S,SW,W,NW,N,NE` (e.g., 1,8,7,6,5,4,3,2 for taudem).\n\n## Requirements\n\n* C compiler with [OpenMP](https://www.openmp.org/) support\n* [GDAL](https://gdal.org/)\n\nFor Windows, use [MSYS2](https://www.msys2.org/) and [OSGeo4W](https://trac.osgeo.org/osgeo4w/) to install [GCC](https://gcc.gnu.org/) and [GDAL](https://gdal.org/), respectively.\n\n## How to compile MEFA\n\n```bash\nmake\n```\n\n## Benchmark algorithms\n\n* [MEFA-HP](https://github.com/HuidaeCho/high_performance_flow_accumulation) (algorithm index 7)\n* [HPFA](https://github.com/HuidaeCho/high_performance_flow_accumulation) (algorithm index 1)\n* [FastFlow](https://github.com/HuidaeCho/FastFlow) (Zhou's algorithm)\n* [AreaD8](https://github.com/dtarb/TauDEM)\n* [ArcGIS Pro Flow Accumulation](https://pro.arcgis.com/en/pro-app/latest/tool-reference/spatial-analyst/flow-accumulation.htm)\n\n## Pre-/post-processing scripts\n\n* [1.import_ned.zip](https://data.isnew.info/mefa/1.import_ned.zip)\n* [2.prepare_inputs.zip](https://data.isnew.info/mefa/2.prepare_inputs.zip)\n* [3.run_algorithms.zip](https://data.isnew.info/mefa/3.run_algorithms.zip)\n* [4.check_outputs.zip](https://data.isnew.info/mefa/4.check_outputs.zip)\n* [5.analyze_outputs.zip](https://data.isnew.info/mefa/5.analyze_outputs.zip)\n\n## Data\n\nInput flow direction files\n\n* [taud8.tif](https://data.isnew.info/mefa/taud8.zip): AreaD8\n* [fdr.tif](https://data.isnew.info/mefa/fdr.zip): Other algorithms\n\nOutput flow accumulation files\n\n* [meac.tif](https://data.isnew.info/mefa/meac.zip): MEFA\n* [mefahp.tif](https://data.isnew.info/mefa/mefahp.zip): MEFA-HP\n* [hpfa.tif](https://data.isnew.info/mefa/hpfa.zip): HPFA\n* [ffaczhou.tif](https://data.isnew.info/mefa/ffaczhou.zip): FastFlow\n* [tauad801.tif](https://data.isnew.info/mefa/tauad801.zip): AreaD8\n* [fac.tif](https://data.isnew.info/mefa/fac.zip): ArcGIS\n","project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fhuidaecho%2Fmefa","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Fhuidaecho%2Fmefa","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fhuidaecho%2Fmefa/lists"}