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.

2

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

3

CHyF and other Models

4

● 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

5

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

6

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

6

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

7

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

8

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?

10

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

12

CCMEO’s GeEAU Program: here