Web Services

Creating a Web-mapping Application for Fisheries Samples in George Washington Birthplace National Monument

PROBLEM

The National Park Service needs a custom web-mapping application that allows the user to input a buffer distance and query fish sampling sites for George Washington Birthplace National Monument.

ANALYSIS

Spatial queries using Structured Query Language (SQL) were used against a registered enterprise geodatabase to create a view that showed all the sampling locations where game fish and non-game fish species had been recorded (see related topic on Databases and Data Management page). The view was used to create a feature class that was imported into the geodatabase and published to the server. I used Esri’s Web AppBuilder to create a web-mapping application that showed the results of a user-defined query to locate either a game fish or a non-game fish using its common name by configuring a query widget. To allow a user to define a buffer distance required building a model using ModelBuilder and publishing the results as a geoprocessing service (Fig. 1). The geoprocessing service is consumed by adding it to a geoprocessing widget in the application.

Fig. 1. A model in ModelBuilder that was published as a geoprocessing service to allow a user to input a distance to buffer the fish sampling locations.

RESULTS

The web-mapping application includes standard features like configured pop-ups and the ability to print the map. Specialized features include the user’s ability to select a fish species and weight limit and output the results as a map layer (Figs. 2 and 3). The geoprocessing service allows the user to select a buffer distance and output the results as a map layer (Figs. 4 and 5).

Fig. 2. The interface that allows a user to run a customized query for specified fish species of a specified weight.
Fig. 3. The results of the custom query show the locations that meet the user’s specifications.
Fig. 4. The interface that allows the user to run a customized geoprocessing service (buffer) of the fish sampling locations.
Fig. 5. The results of the custom buffer process show the locations and the desired buffer.

REFLECTION

Relational database management systems allow a custom query to be created that can be published and used in a custom web-mapping application that allows a user to specify parameters for queries or geoprocessing services. Understanding how to use the relationships among the tables in the database and perform spatial queries can be applied to a variety of situations, allowing a wide range of customizations to web-mapping applications.


Creating a Web-mapping Application to Determine the Impact of a New Power Line in the New River Gorge National River

PROBLEM

A web-mapping application is needed to determine the impact of a proposed power line to the natural and cultural history of the New River Gorge National River. After building the database to house the data you need to publish the appropriate services and build the web-mapping application.

ANALYSIS

The data are in tabular and spatial format and are housed in an enterprise geodatabase (see related topic on Databases and Data Management page). I used Structured Query Language (SQL) to create a view of the vertebrate monitoring sites, and then created a feature class from this view and imported into the database. A model was created using ModelBuilder to allow the user to buffer a proposed power line so they could determine the impact on the vertebrate monitoring sites and the buildings (Fig. 1). The geoprocessing, feature, and mapping services were published and used in a web-mapping application.

Fig. 1. A model in ModelBuilder that was published as a geoprocessing service to allow a user to input a distance to buffer the fish sampling locations.

RESULTS

The web-mapping application allows the user to create a proposed power line and then run a geoprocessing service (using a user-defined input of buffer distance) that will show the buildings and vertebrate monitoring locations that would be impacted (Fig. 2). The results are drawn on the map and the user can click on the features that fall within the buffer to obtain information about the vertebrates or buildings that would be impacted by the power line (Fig. 3).

Fig. 2. The web-mapping application with the geoprocessing interface that shows the user-defined buffer distance.
Fig. 3. The web-mapping application shows the results of the custom buffer of the proposed power line. The user can click on a feature to see what would be impacted by the new power line.

REFLECTION

Web-mapping applications can bring data to a user to solve a variety of problems. I leveraged the power of a relational database management system to customize a query to create spatial data. I used custom geoprocessing to solve a unique problem. These skills can be applied to many types of data to answer many questions.

Developing a Mobile Data-Collection Tool for Assessing Wetlands

PROBLEM

              Methods are available for describing and assessing wetland condition and they vary in scope and detail from low detail to an intensive assessment. In general, field-assessment of a wetland is done using a paper form, but the functionality of mapping the wetland is missing. A web-mapping application is needed to demonstrate the feasibility of incorporating a mapping feature directly within a data-collecting form to assess and map wetlands simultaneously.

ANALYSIS

              I used Collector for ArcGIS to create this application. A file geodatabase is needed so that domains can be defined, which correspond to the fields that will be filled in with data once the wetland’s feature is drawn (Fig. 1). A new feature class is created in the geodatabase with fields using the domains just created. Symbology is set using the desired field, in this case, the wetland’s condition (Fig. 2). The data are published as a service, and in ArcGIS Online (AGOL) a web map is created with this layer and pop-ups are configured appropriately.

Fig. 1. Dialog box for defining the domain showing the properties associated with the buffer domain.
Fig. 2. Dialog box for setting symbology for each wetland, mapped based on the condition of the wetland.

RESULTS

              The data that were published is a feature service that can be added to a web map. The web mapping application allows a user to easily enter the outline of a wetland and all the properties associated with assessing the function of the wetland without any knowledge of GIS or web mapping (Fig. 3). The web map is automatically updated with the newly created wetland features when the data are submitted. Once the data are submitted the map and the data are available.

Fig. 3. Information about the condition of the wetland is entered as the wetland is mapped, once the map is saved this information is available to anyone using this map.

REFLECTION

              Collector for ArcGIS is a convenient tool that can be customized for a variety of mapping and data-collecting applications. I learned how to define domains to control the data that a user can input. I created this tool to be used for mapping wetlands as they were assessed because, in the past, I have used paper forms for collecting data and I had no way of mapping the wetland other than to collect coordinates. While most rapid wetland-assessment forms would include many more variables than presented here, this application was designed to serve as a proof-of-concept, or prototype. By understanding how to define a domain and create a feature class with fields that depend on these domains, this tool can be customized for any purpose. I already have plans to apply this tool for data collection for future projects.