{"id":1168822,"date":"2021-03-23T16:56:52","date_gmt":"2021-03-23T23:56:52","guid":{"rendered":"https:\/\/www.esri.com\/arcgis-blog\/?post_type=blog&p=1168822"},"modified":"2024-01-31T09:55:13","modified_gmt":"2024-01-31T17:55:13","slug":"hms-prepro-an-automated-gis-toolbox-for-extracting-cloud-based-data-delineating-watersheds-and-calculating-hydrological-parameters","status":"publish","type":"blog","link":"https:\/\/www.esri.com\/arcgis-blog\/products\/arcgis-desktop\/water\/hms-prepro-an-automated-gis-toolbox-for-extracting-cloud-based-data-delineating-watersheds-and-calculating-hydrological-parameters","title":{"rendered":"HMS-PrePro: An Automated GIS Toolbox for Extracting Cloud-based Data, Delineating Watersheds, and Calculating Hydrological Parameters"},"author":4911,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"open","ping_status":"closed","template":"","format":"standard","meta":{"_acf_changed":false,"_searchwp_excluded":""},"categories":[23051],"tags":[572002,230422,23371,25631,37771],"industry":[],"product":[421922,37031,36991],"class_list":["post-1168822","blog","type-blog","status-publish","format-standard","hentry","category-water","tag-arcgis-living-atlas","tag-data","tag-hydrology","tag-spatial-analysis","tag-water","product-arcgis","product-spatial-analyst","product-arcgis-desktop"],"acf":{"short_description":"HMS-PrePro is an ArcGIS preprocessing tool that was designed to improve GIS-based watershed modeling.","flexible_content":[{"acf_fc_layout":"content","content":"

HMS-PrePro is an ArcGIS preprocessing tool that was designed to improve GIS-based watershed modeling. The tool rapidly creates a basin model and estimates hydrological parameters for any watershed in the world by connecting the user to Esri\u2019s Living Atlas of the World<\/a> and automating spatial analysis<\/a> steps.<\/p>\n

When the user specifies a watershed boundary, HMS-PrePro connects to ArcGIS REST API Servers<\/a> and uses the watershed location as a common denominator to link distinct spatial datasets for the area of interest. Authoritative datasets are extracted from Living Atlas servers and downloaded to the user\u2019s computer for further processing. Common datasets required for standard hydrological modeling are obtained, including land cover<\/a>, terrain elevation<\/a>, and hydrological soils<\/a> data. Instead of requiring the user to search a plethora of websites, each with unique formats, and then download, extract, and process the data locally, HMS-PrePro automates these steps within a matter of minutes. The data is stored and managed locally in a format that is amenable to typical hydrological modeling.<\/p>\n

The tool then performs a series of spatial analysis steps to delineate the watershed by linking with the Arc Hydro Toolbar<\/a> and the Hydrology Toolset<\/a> in ArcGIS ArcMap. The program manipulates the digital elevation model (DEM) and performs terrain processing steps for delineating the watershed boundary into catchments, reaches, and longest flow paths. The DEM processing in HMS-PrePro follow the standard steps used by Arc Hydro, including:<\/p>\n

Fill Sinks, Flow Direction, Flow Accumulation, Stream Definition, Stream Segmentation, Catchment Grid Delineation, Catchment Polygon Processing, Drainage Line Processing, and Longest Flow Path (see Arc Hydro Tutorial<\/a>)<\/p>\n

With the datasets downloaded and the DEM processed, the tool then assigns a unique hydrological identifier to each watershed element for connecting common features. The aforementioned steps are executed in succession when the user runs the HMS-PrePro GetData<\/em> script tool. Runtimes vary depending on the size of the watershed, computing capability, internet speed, and user-specified stream definition threshold (see Arc Hydro Tutorial<\/a>); however, observed execution times are generally between 3 – 5 minutes.<\/p>\n

The user may then run the HMS-PrePro Preprocess Basin<\/em> script tool to estimate a variety of common hydrological parameters using the downloaded datasets. Execution times for this script tool are generally less than one minute. Hydrological methods supported by HMS-PrePro include:<\/p>\n

Canopy Method, SCS Curve Number Lag Method, TR-55 Lag Method, SCS Curve Number Loss Method, Green and Ampt Loss Method, Lag Routing, Muskingum-Cunge Routing, SCS Unit Hydrograph, Clark Unit Hydrograph, Snyder Lag Method
\n(see HEC-HMS User\u2019s Manual<\/a>)<\/p>\n

Parameters are estimated using a series of spatial analysis steps and appended to the local Catchment and Reach shapefiles. An output text file is then created in the format necessary to be automatically read by the U.S. Army Corps of Engineers HEC-HMS<\/a> hydrological software for creating a Basin Model<\/a>, which describes the physical properties of the watershed system prior to calibrating and applying atmospheric conditions. While the output text file is specific to HEC-HMS, the tool\u2019s functionalities of creating a comprehensive hydrological basin model using web-based datasets and parameter estimates may be used to streamline initialization steps for a variety of hydrological applications. Data downloading, processing, and spatial analysis are common steps, that are typically lengthy and tedious, for preparing a watershed model from GIS datasets, irrespective of the final simulation software used to route the rainfall into runoff hydrographs.<\/p>\n

The tool\u2019s conceptual framework was originally presented in a 2016 ArcUser Article<\/a> as a novel way to improve hydrological modeling by connecting the user with authoritative, seamless, cloud-based datasets, such as those hosted in Esri\u2019s Living Atlas of the World. At that time, the tool was not operational for public use but was rather a proposed concept for improving existing hydrological techniques. HMS-PrePro was deployed as a public software in 2020 with the publication of the article \u201cGIS preprocessing for rapid initialization of HEC-HMS hydrological basin models using we-based data services\u201d in Environmental Modelling & Software (here<\/a>).<\/p>\n