Silverlight Web Mapping Interface for Sediment Pollution Assessment of Abandoned Developments Using Volunteered Geographic Information

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22 févr. 2014 (il y a 3 années et 5 mois)

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Silverlight Web Mapping Interface for Sediment Pollution Assessment of

Abandoned Developments Using Volunteered Geographic Information

Joshua D. Werts
1
, Elena A. Mikhailova
1
, Christopher J. Post
1
, and Julia L. Sharp
2

1
Department of Forestry and Natural Resources, Clemson University, SC 29634, USA

2
Department of Applied Economics and Statistics, Clemson University, SC 29634, USA


ABSTRACT



INTRODUCTION



Over
recent years, the upstate region of South
Carolina has experienced an unprecedented amount of
growth in population and in the area of developed land
(Allen and
Wyche
, 2008
).
In the past several years following
the burst of the housing bubble, an unprecedented number
of residential construction sites in upstate South Carolina
have been left unfinished. This may allow soil to erode into
streams and lakes past unmaintained erosion control
devices.
There is an urgent need to further identify the extent of this
problem and engage the public.


We have developed an online web mapping interface
to: 1.)
d
isplay sample photos and sites from the original
study, 2.)

allow
visitors
to submit the
location as well as
pictures and comments about their own subdivisions or sites
they have identified
, 3.) allow users to view and comment on
other users’ submissions, 4.) further map and identify the
overall extent of sediment pollution from abandoned
developments and/or identify hotspots of abandoned
developments for further analysis.


We have launched a pilot study to evaluate this
website’s usability based on effectiveness, efficiency,
satisfaction and the degree of public engagement (
Meng

&
Malczewski
, 2010).


CONCLUSIONS


We have developed a website utilizing the ESRI ArcGIS API
for Microsoft Silverlight and are currently collecting user
-
generated content and survey data to evaluate its usability
and overall effectiveness. Through this website, we hope to
inform the public about a critical soil and water resource
issue resulting from the current economic crisis. The
website is available at:
http://www.AbandonedDevelopments.com


ACKNOWLEDGEMENTS


We wish to thank and acknowledge the Greenville, Pickens,
and Spartanburg county GIS departments for making aerial
photos and GIS data available to us. Financial support for
this project was provided by South Carolina Water Resources
Center and the Clemson University Public Service and
Agriculture Next Generation Graduate Fellowship (PSA
-
NGGF).


REFERENCES

Figure 1
.
Basic Model for Website Functionality


RESULTS AND DISCUSSION


MATERIALS AND METHODS


RESULTS AND DISCUSSION


Contact:
Josh Werts, joshwerts@gmail.com, http
://www.joshwerts.com, http://www.AbandonedDevelopments.com


GIS analysis during the economic crisis (2010) indicated abandoned
and unfinished housing developments as a potential source of soil
erosion and sedimentation to water bodies in upstate South Carolina. Of
119 visited sites, approximately 40% contributed sediment directly to
streams. There is an urgent need to further identify the extent of this
problem and increase public awareness. An online GIS tool provides the
means to reach a large number of people and access local knowledge.
We developed an online web mapping interface utilizing the ArcGIS
Silverlight application programming interface to solicit volunteered
geographic information. The website allows the public to upload photos
and attributes of their own subdivisions or local problem areas and
explore other

submissions. The mapping interface integrates Silverlight 4,
Bing Maps, ArcGIS Server 10, and the Google
GData

Picasa API to create a
rich user experience. The website was made available to the public in
early February 2011 at http://www.AbandonedDevelopments.com.


Silverlight
-
enabled WCF web services
:


ArcObjects code for ArcSDE storage of new
submittal points and attributes.


Proxy connection to Picasa server for photo
functions.


Error logging to SQL Server database.



Google Picasa Web Albums Data API:


Storage and retrieval of uploaded photos.


Storage of photo comments.


Automatic generation of photo thumbnails.


Automatic generation of compressed image for
web display.


External server reduces load and storage on our
on
-
site server
.



RSS:


Publish RSS feed for new submissions.

Allen, J and B.
Wyche
.
2008. Growth projections for upstate South
Carolina.

Available
at

http://www.upstateforever.org/newsviews_other/ProjectedGrowth.p
df (accessed 1 May 2009). Upstate Forever, Greenville, SC.

ESRI
, Inc.
2010. ArcGIS Server 10,
Redlands, CA.

Meng
, Y. and J.
Malczewski
.

2010. Web
-
PPGIS usability and public
engagement: A case study in
Canmore
, Alberta, Canada. Journal of the
Urban and Regional Information Systems Association. 22(1): 55
-
64.

Red!

Web Mapping Interface Components (Figure 1):


ESRI ArcGIS API for Microsoft Silverlight:


Framework for Silverlight web mapping interface.


Displays site polygons, points, and polylines from
ArcGIS Server REST services and ArcSDE database.


Utilizes Bing Maps base layers.

Figure
2
. Site, features, and photo bar thumbnail display

Figure
3
. Photo display window

MATERIALS
AND METHODS

Figure
4
. Zoom map to photo location

Figure
5
. Submittal form

Usability and Public Engagement:


The website will be evaluated based on:


Effectiveness:


Percentage of users successfully completing
submissions.


Locational accuracy and correctness of
submissions.


Public perception of sedimentation from
abandoned developments before and after using
website.


Efficiency:


Time to complete submission and/or percentage
of users successfully completing submissions
(survey and custom events tracking submittal time
in Google Analytics).


Ease of learning:


How to navigate map (survey).


How to explore submittals (survey).


How to submit development (survey).



Satisfaction:


User’s overall satisfaction with interface (survey).


Will a website
like this
be
effective in promoting
environmental awareness and
change? (survey).



Public Engagement:


Google Analytics data (number of site visits, visitor
locations, time on site, number of images viewed,
etc.)

User Submissions
:


Displays user contributed photos and locations.


Allows for commenting from other users.


Submit Problem Development
:


Prompts for photo upload:


Uses GPS coordinates if photo is geo
-
tagged,
otherwise, prompts user to click on map in
proper location.


Submittal
form (
Figure 5
):



Does site appear abandoned?


How long since most recent activity on site?


Is sediment entering a stream?


Description of problem.

Phase II?

Main Web Mapping Interface Features:


Original Study Data:


Displays features and photos from sample of sites
documented in previous study. (
Figure 2
).


User clicks on point or polyline to identify feature.
Photo bar automatically scrolls to proper photo
and photo is opened in photo window (
Figure 3
).


Alternately, user selects thumbnail from photo
bar to load photo window and then has the option
to “Zoom map to pic location” (
Figure 4
).

RESULTS AND DISCUSSION