mark sondheim & marie-eve martin highlights and demonstrations · hydrography program...
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Hydrography ProgramHighlights and Demonstrations
2018-05-09, RestonNorth American Mapping
Mark Sondheim & Marie-Eve Martin
Overview
➔ Common Hydrology Features model: CHyF (chief)➔ Linked Open Data: LOD
● Stream Gauge Data
● Groundwater Data
● Meteorological Data
● Etc.
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CHyF: A product of innovation and collaboration
● The National Hydro Network in Canada does not provide sufficient support for analysis. Drainage boundaries do not exist and neither does support for upstream/downstream navigation.
● The US model is very rich, but it is complicated. ExtendingIt across all of Canada would be lengthy and expensive.
● This issue raises the question: are there alternatives based on advances in computer science and software engineering?
● And the related question: are there alternatives that will provide high performance, but require much lower maintenance?
NRCan
IJC
QuébecOntario
NOAA
USGS
ECCC
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CHyF and other Models
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● Many models of hydrological features have been put forward over the last 40 years.
● HY_Features is a new OGC conceptual standard. CHyF extends it and provides an implementation.
● CHyF leverages fast computation, including AI.
1980s Today
Google Maps
Fast Spatial Algorithms
Computing Power
US NHD
BC 1:50K Watershed Atlas
BC 1:20K Freshwater Atlas
US NHDPlus
HY_Features
Canada NHN
CHyF
Ontario Hydro Network
US NHDPlus HR
Québec GRHQ
Basic digitizing GPS positioning, web servicesLimited computational capability Extensive computational capability
CHyF’s Development
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HY_FeaturesUnderwritten by
● Open Geospatial Consortium
● World Meteorological Organization
CHyFLessons learned
Conceptualframework
Leveraging
Advances in Computation● Advances in graph theoretic
algorithms ● Advances in vector algorithms● AI related algorithms● Advances in computing
Hydro Harmonization Projects● International Joint Commission● US Geological Survey● Natural Resources Canada● Environment and Climate
Change Canada
Expert Consultation● 2017 Hydro Online Survey:
hydrologists, other specialists● Direct interaction
CHyF as a Key Component of Hydrological Analysis
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Services
Data
Apps
CHyFNavigation
Web Services
Hydrological Web Services
Linked DataWeb Services
GeospatialWeb Services
Meteorological Web Services
CHyF HydrologyFeatures
Data Store
Land Use / Land Cover Data Store
Hydrometric Station
Data Store
Groundwater Monitoring Data Store
Municipal Boundaries Data Store
CHyFConditioned
DEMData Store
Meteorological Data Store
Pollution Path Routing
FloodPrediction
Water Supply Analysis
Climate Change
Assessment
Emergency Response Support
Web Browsers & Search Engines
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CHyF Technical Characteristics
● Makes use of graph theory, like road navigation and social media analysis
● Defines catchments in a hydrologically meaningful way
● Expected to scale well, from local to continental scales
● Promise of much lower maintenance with far easier updating
● Its use with linked open data has been demonstrated
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CHyF’s Elementary Flowpaths & Catchments
● Elementary flowpaths (each of the line segments, dot to dot, a - k)
● Elementary catchments(each of the areas, A - K)
● Nexuses(each of the white, green, and red dots)
AB
HCE
G D
F
I
J
K
j
i4
d
c
b
a
h
g
f
e
i1i2
i3
i5
i6 i7i8
i9
k
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CHyF leverages Graph Theory
A watershed is represented by a hy-graph: (i) typically one big sub-graph, representing connected areas, and
(ii) many small sub-graphs, representing disconnected areas.
One big sub-graph, from the previous example
Assume two isolated lakes and an isolated stream network are also present. Each would have its own sub-graph.
T0
T1 T2 T3
W ← ∑ Ti
The watershed (or a series of watersheds) is represented by W, a single hy-graph.
● The graph must be directed and acyclic. ● All parts of the land/waterscape are referenced in the hy-graph.
9Cenotes and subsurface flows could be handled in a similar fashion.
Technical Environment● CHyF Services
○ The software is open source under Apache License 2. It can be used in an open source stack with the Geospatial Data Abstraction Library (GDAL), QGIS, PostGIS, etc.
○ Although not demonstrated yet, it is likely that with some minor extensions it could be used with ArcGIS Pro using ArcPy.
● CHyF Data
○ GeoJSON, GeoPackage, GML?, Shapefile?
○ WMS, WFS?
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External Advisory Committee● James Craig, Ph.D., P.Eng. – Chair
Canada Research Chair in Hydrologic Modelling and Analysis, Associate Professor, Civil and Environmental Engineering, University of Waterloo
● Wayne Jenkinson, Ph.D., P.Eng.Senior Engineering Adviser, International Joint Commission
● Kevin Shook, Ph.D., P.Eng.SGI Canada Research Fellow, Global Institute for Water SecurityResearch Fellow, Centre for Hydrology, University of Saskatchewan
● Bernhard Lehner, Ph.D.Associate Professor, Department of Geography, McGill University
● John GaiotMapping and Geomatics, Ontario Ministry of Natural Resources
● Daniel BlaisDirection de l'expertise en biodiversité; Ministère du Développement durable, de l'Environnement et de la Lutte contre les changements climatiques 11
North America● Seamless coverage at all scales● Either a common model everywhere,
or interoperable models, supporting:○ Networks of waterbody features○ Networks of catchments○ Navigation services through the networks
CanadaUSA
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CCMEO’s GeEAU Program: here