Geography 482/582
Final Project: Watersheds in ArcHydro
Due Date:3/9/2011 in exam 2
Students are encouraged to use knowledge gained inside and outside class to createageodatabase database model in support of developing a Puget Sound coastal watershed database design being developed for WAGDA 2.0.
Students must work in teams of two or three persons. A project should use techniques and concepts learned in lecture and lab sections.
Project Products
There are five products associated with the final project. All students in group will receive the same score resulting from the assessment of the products.
1.Status Report 1: Problem Statement and Database Design (10 points) – due February 22 in lab section
1.1 Problem Statement
a. One-half to one-page description of content and scope of project.
b. A well-formed research question(s) with connection to the background problem statement.
The following phrasesmight be used in developing a research question:
- Protect existing habitats and prevent further losses in watersheds
- Restore the amount and quality of habitat and reduce fragmentation
- Reduce pollution from human and animal waste enteringPuget Sound
- Improve water quality and habitat by managing storm water runoff
- Provide water for people, fish and wildlife, and the environment
- Protect ecosystem biodiversity and recover imperiled species
c. Annotated bibliography of literature references (minimum 5) related to background issues.
1.2 Preliminary Database design – See Lesson 2 slides 25 - 49
a. Table that contains three columns: feature class names, definitions, and data source references WAGDA is not a direct source reference, use actual organization source name.
b. High-level schema diagram using ArcGIS Diagrammer, e.g. feature classes and feature datasets.
2. Status Report 2: Operations Design (10 points) – due March 1st in lab section
Operational geodatabase schema diagram using ArcGIS Diagrammer, with a table of attributes for each of the feature class, plus feature datasets, feature classes, relationship, domain, subtype, topology, and/or geometric network.
3.Final Project Presentation(15 points)(TBA)
Presentations delivered in section in last week of classes.
4. Final Project Report (35 points) due March 9 at exam 2
5.Student Peer Evaluation (required, separate from project report;due March 9 at exam 2.
Application Contexts for Enterprise GIS Database Management
Geog 482/582 is a database course,thus our focus involves preparation of a sub-basin/watershed database. Every database is commonly used by an application, or for that matter many applications as in an Enterprise GIS database context. There are at least two, and perhaps many more, contexts we can imagine.
One contextmight be a need for Puget Soundsub-basin characterizations that can be used for Envision land use modeling software as input to OpenNSPECT nonpoint source pollution modeling software. See the report on Puget Sound Alternative Futures that identifies seven sub-basins in the Puget SoundBasin(Bolte, J and Vache K. 2008). The Final Report (pdf) for the project is available here. Envision software was used to explore trajectories of change in the Puget Sound Region of Washington. The project undertook a broad analysis of the region focused on understanding impacts of alternative growth and development strategies on nearshore ecosystem processes and services. The study area contained a mixture of agriculture, forest, urban, and rural residential lands. The study was funded by the Washington Department of Fish and Wildlife. More information about Envision is available at More information about NSPECT is available at
A second context is developing landscape forms based on watershed characterizationfor use in the Intrinsic Landscape Aesthetic Resource Information Systems (ILARIS) developed by Jones and Jones (Jones, G. 2007). The motivation for option 2 stems from a need for watershed characterizations that can be used for explorations of watershed sustainability by stakeholder groups, particularly how transportation corridors influence watershed sustainability. For a brief overview of ILARIS see From the document: “Jones & Jones has created an open-source, watershed-based GIS tool to help landowners and community leaders identify the foremost examples of their regional landscape—their signature landscapes—and to support decision-making to protect these scenic, ecological, and culturally sensitive lands. The ILARIS model is adaptable and can be used to process the characteristic landscape data from any region. By measuring and monitoring the intrinsic aesthetic landscapes, we can help communities understand how comparatively rare these landscape features are in their own sub-regions, in the larger regions, and, in fact, in the world.
ILARIS Resource page
Note: Both contexts require ArcHydrodrainage characterization (see below), and therefore there is a single set of instructions to help you prepare the data no matter which option you choose.
ArcHydro Model for Surface Water Resources
Arc Hydro is a geospatial data model for water resources that operates within ArcGIS (Maidment, 2003). The data model supports hydrologic simulation models for obtaining a deeper understanding of surface water systems. The Arc Hydro data model is composed of four feature datasets – drainage, network, hydrographic, and channel.
You are provided step-by-step instructions for a drainage analysis of WRIA9 (Water Resource Inventory Area 9—the Green/Duwamish and Central Puget Sound Watershed). The major functionalities are available in the Arc Hydro tools for Raster Analysis. You will have to translate the instructions to apply to Snoqualmie watershed in four scales:1)2,560 acres (10.3599524 square kilometers)2) 640 acres (2.58998811 square kilometers)3)160 acres (0.647497028 square kilometers), and 4)40 acres (0.161874257 square kilometers).(See step 28 for details)
*****This guide below is not a part of your final report*****
Preparations:
Copy the data from your student folder. ThelabAssignment5 folder contains the following folders and files:
labAssignment5\data\wria9mask
labAssignment5\data\wtrcrs_wria9.shp
ArcHydro Tools 1.3 for ArcGIS 9.2/9.3 can be downloaded from
After unzip, please read “QuickStart.txt”that can be found in the package carefully before installation. This txt file provides what you might need for a successful installation.
Creating Stream Network Geodatabase in WRIA9 using ArcHydro
1.Open ArcCatalog and create a new folder “LabAssignment5”. Then create a new personal geodatabase named “ArcHydrowria9” in the folder. Close ArcCatalog.
2.Open ArcMap and create a new empty map, and save it as “ArcHydrowria9.mxd”. Then, right click on the menu bar and select “ArcHydro Tools”.
(Please note: this interface (1.2 version) is a bit different from what you will see when using 1.3 version)
3.Also, Spatial Analyst Extension needs to be activated.
4.First, you need to set ‘Target Location’. The location of the vector, raster, and time series data can be explicitly specified using the function “ApUtilities” “Set Target Location”. (It is on the ArcHydro Toolbar.)
5.Set both ‘DefaultConfig’ and ‘HydroConfig’ (double click on them) tofollowing paths:
- Raster Data: C:\....\LabAssignment5\ArcHydro\
- Vector Data: C:\....LabAssignment5\ArcHydro\ArcHydrowria9.mdb
- Time Series: C:\....LabAssignment5\ArcHydro\ArcHydrowria9.mdb
6.Add wtrcrs_wria9.shpand wria9mask (DEM) to TOC.
Now, we are going to start “Terrain Preprocessing”. We will use DEM to identify the surface drainage pattern. Once preprocessed, the DEM and its derivatives can be used for watershed delineation and stream network.
DEM Reconditioning:
7.This function modifies a DEM by imposing linear feature onto it (burning/fencing). For a full reference to the procedure refer to the web link
8.On ArcHydro Toolbar, select “Terrain Preprocessing” “DEM Manipulation”“DEM Reconditioning”
9.Select wria9maks for ‘Raw DEM’ and wtrcrs_wria9 for ‘Agree Stream’ and leave the default name AgreeDEM for ‘Agree DEM’, click “OK”
10.Leave ‘Define Agree parameters’ as the default values, click “OK”
11.Click “NO” when it asks you to raise the DEM for the negative elevations, and then click “OK”. (In this case, it is not necessary to eliminate the negative values because all those negative value are located on the shoreline.)
Fill Sinks:
12.If a cell is surrounded by other cells with higher elevation, water is trapped in that cell and cannot flow. This function fills the sinks in a grid by modifying the elevation value to eliminate these problems. Select “Terrain Preprocessing” “DEM Manipulation” “Fill Sinks”
13.Make sure that the input for DEM is “AgreeDEM” and the output Hydro DEM is named by default value “Fil”.
14.When the process is successfully completed, click “OK”.A layer called “Fil” will be added to the map view.
Flow Direction:
15.This function computes the flow direction for a given grid. The values in the cells of the flow directioin grid indicate the direction of the steepest descent from that cell. Select “Terrain Preprocessing Flow Direction”.
16.Make sure that the input file for Hydro DEM is “Fil” and the output ‘Flow Direction grid’ is named as “Fdr”.
17.Click “OK” when the operation completed.
18.Open the attribute table of “Fdr”. You can give an interpretation for the values in the Value field of the Flow Direction table.
Flow Accumulation:
19.This function computes accumulated flow as the accumulated weight of all cells flowing into each downslope cell in the output raster. More information about flow accumulation at:
20.Select “Terrain Preprocessing ”“Flow Accumulation”.
21.Make sure that the input file for ‘Flow Direction Grid’ is “Fdr” and the output ‘Flow Accumulation Grid’ is named as “Fac”. Click “OK”.
22.Click “OK” when the operation is successfully completed. The flow accumulation grid “Fac” will be added to the map view.
23.One-click on the color ramp of “Fac” in TOC, and choose “Invert” to invert color ramp.
24.In TOC, movewtrcrs_wria9 to the top and make this layer visible.
25.Compare the stream layer with the flow accumulation file in order to estimate the flow accumulation value representing stream in WRIA9. (Transparency at 75%is needed to show the comparison between the two layers)
Stream Definition:
26.The Stream Definition calculates a stream grid containing a value of “1” for all the cells in the input flow accumulation grid that have a value greater than given threshold. All other cells in the Stream grid will contain no data. Select “Terrain Preprocessing”“Stream Definition”.
27.Confirm that the input file for ‘Flow Accumulation Grid’ is “Fac” and the output ‘StreamGrid’ is named as “Str”. Click “OK”.
28.Enter stream threshold to initiate stream:
Area (square kilometer): 0.161874 (number of cells will change automatically)
The smaller threshold will result in a denser stream network and usually in a greater number of delineated catchments.
29.Click “OK”. The stream grid “Str” will be added to the map view.
Stream Segmentation:
30. This function creates a grid of stream segments that have a unique identification. A segment may be a head segment. Or it may be defined as a segment between two segment junctions. All the cells in a particular segment have the same Grid code that is specific to that segment. Select “Terrain Preprocessing” “Stream Segmentation”.
31.Make sure that inputs of Flow Direction Grid and Stream Grid are “Fdr” and “Str”, respectively. And the output ‘Link Grid’ is named as “Lnk”. Click “OK”, when the process is successfully completed.
Catchment Grid Delineation:
32.The Catchment Grid Delineation function creates a grid in which each cell carries a value indicating which catchment the cell belongs. The value corresponds to the value carried by the stream segment that drains into that area, defined in the stream segment link grid. Select “Terrain Preprocessing” “Catchment Grid Delineation”.
33.Confirm that the inputs of Flow Direction Grid and Link Grid are “Fdr” and “StrLnk”, respectively. And the output file ‘Catchment Grid’ is named as “Cat”. Click “OK”. Click “OK” after the process is successfully completed.
Catchment Polygon Processing:
The three functions Catchment Polygon Processing, Drainage Line Processing and Adjoint Catchment Processing convert the raster data developed so far to vector format. The raster data created so far have been stored in a folder named “Layers”. The vector data will be stored in a feature dataset also named “Layers” within the geodatabase.
The feature dataset created by Catchment Polygon Processing reportedly inherits the extent from the top layer in the ArcMap document map view. Therefore the top layer should be one that occupies the full extent needed. If the layer on the top is of lesser extent then some polygons may be omitted and Adjoint Catchment Processing step to be done later will fail.
34.Select Terrain Preprocessing Catchment Polygon Processing.
35.Make sure that the input ‘Catchment Grid’ is “Cat” and the output ‘Catchment’ is named as “Catchment”. Then, click “OK”
36.Click “OK” again, when the process is successful completed.
37.Now you have a new catchment layer (vector data). Examine its attribute table. Notice that each catchment has a HydroIDassigned which is a unique identifier within the ArcHydro geodatabase. Each catchment also has Shape_Length and Shape_Area field. These quantities are automatically computed when a feature class becomes part of a geodatabase.You can also open ArcCatalog to examine whether the data you created have been placed in your folder.
38.40 acres / 0.161874257 square kilometers This function converts the input Stream Link grid into a Drainage Line feature class. Select Terrain Preprocessing Drainage Line Processing
39.Confirm that the inputs of Stream Link Grid and Flow Direction Grid are “StrLnk” and “Fdr”, respectively. And the output is named as “DrainageLine”.
40.Click “OK”. Click “OK” when the process is successfully completed.
41.Open the attribute table of “DrainageLine”. Each row has a HydroID assigned that is a unique identifier within the geodatabase (different from Catchment HydroID). The GridID field gives the identifier of the catchment in which each polyline resides.
Adjoint Catchment Processing:
42.This function creates the aggregated upstream catchment from the “Catchment” feature class. For each catchment that is not a head catchment, a polygon representing the whole upstream area draining to its inlet point is created and stored in a feature class that has an “Adjoint Catchment” tag. This feature class is used to speed up the point delineation process.
43.Select Terrain Preprocessing Adjoint Catchment Processing
44.Make sure that the input of Drainage Line is “DrainageLine” and input of Catchment is “Catchment”. And the output Adjoint Catchment has the default name “AdjointCatchment”.
45.Click “OK”; then, click “OK” again when the process is successfully completed.
Drainage Point Processing:
46.The Drainage Point Processing function allows generating the drainage points associated to the catchments. Select Terrain Preprocessing Drainage Point Processing.
47.Make sure that the input of Flow Accumulation Grid is “Fac” and input of Catchment Grid is “Cat”. And the output Drainage Point has the default name “DrainagePoint”.
48.Click “OK”; then, click “OK” again when the process is successfully completed.
49.Examine the attribute table of DrainagePoint, notice that HydroID are the unique values.
Now, you have had DrainageLine, Catchment, and DrainagePoint. You are going to use these three feature classes to create Hydro Network using ArcHydro Tool.
Hydro Network Generation:
50.This function uses DrainageLine, Catchment and DrainagePoint feature classes to create network features and the associated geometric network. It also creates a relationship class between new HydroJunction feature class and Catchment feature class called HydroJunctionHasCatchment.
51.On ArcHydro Toolbar, select Network Tools Hydro Network Generation
52.Make sure that the input of Drainage Line, Catchment, and DrainagePoint are “DrainageLine”, “Catchment”,and “DrainagePoint”, respectively. And the output Hydro Edge and Hydro Junction have the default name “HydroEdge” and “HydroJunction”.
53.Click “OK”when the process is successfully completed. The “HydroNetwork Properties” window will show up. Usethe default values and click “OK”.
54.Examine feature classes and attribute tables of HydroEdge and HydroJunction. A Catchment/Watershed is a polygon which is connected to the Hydro Network through a relationship to the HydroJunction at its outlet. HydroID of the HydroJuction is assigned to be the JunctionID of the Catchment/Watershed
Store Flow Direction:
55.Store Flow Direction function reads the flow direction for a set of edges from the network and writes the value of the flow direction to a FlowDir field defined in the XML in the Edge feature Class. Select Network Tools Store Flow Direction
56.Put HydroEdge as an input in the Hydro Edge. Then, click “OK”
Set Flow Direction:
57.The Set Flow Direction tool sets the flow direction for selected/all edges in a network edge feature class. Select Network Tool Set Flow Direction
58.Make sure that the input file of the Hydro Edge is “HydroEdge”. Click “OK”
59.Then, go back to “Set Flow Direction” under Network Tool. Select “With Digitized Direction” and click “OK”. The flow direction is set for the Hydro Edge in the digitized direction.
ArcHydro Tools enablesthe creation ofa geodatabase for surface water resource applications. There are other functions in this tool that support watershed processing and attribute tools. For more information, see ESRI’s Web site for ArcGIS data models at
Additional Data
Both contexts might require additional data. The following table is an example of coastal database model features/processes and potential geospatial data types (Nyerges et al. 2007) that are associated with applications deemed important in coastal data management synthesized from various literature. See Nyerges et al. 2007 paper (URL in references).