Design and Performance Analysis of Terrain Modeling Architecture for WetlandsProject Overview

By Ricardo Veguilla, Javier Malave, Emmanuel Alonso

Overview

Introduction to Wetlands Terrain Modeling Project Description System Design

Introduction to Wetlands

a wetland is an environment "at the interface between truly terrestrial ecosystems...and truly aquatic systems...making them different from each yet highly dependent on both“

Mitsch & Gosselink, 1986

Description A geographic area with

characteristics of both dry land and bodies of water.

Wetlands typically occur in low-lying areas that receive fresh water at the edges of lakes, ponds, streams, and rivers, or salt water from tides in coastal areas protected from waves.

Flora is limited to those that are adapted to wet conditions.

Soil characteristic of a wet environment.

Influence Factors

The characteristics of wetlands are mainly determined by: The amount of water that flows in,

out, and is stored in the wetlands.

and are partially determined by: The sediment flowing with the river

water New river channels formed during

the floods.

Benefits to Wildlife

Provide a variety of food for fishes, waterfowl, and for other smaller organisms that are used as food for larger animals.

Protective emergent plants protect various species from predators.

Benefits to ManWetlands are the best flood control and

mitigation infrastructure known to man.

Wetlands absorb peak flood flows and later release them more slowly, reducing flood damage to property downstream.

Plant life associated with Wetlands help reduce the velocity of water currents.

Water is stored underground or in the

surface of lakes and swamps, reducing the need for building dams, embankments and floodgates which are costly and are known to fail.

How are wetlands lost? Urban or suburban development:

Filling and dredging wetlands for construction projects.

Development can also cause fragmentation of large wetland systems.

Agricultural activities: ditching, draining, and clearing wetlands for farming.

Mining for peat, coal, sand, gravel, and other products.

Natural threats: Erosion, sea level rise, droughts, hurricanes,

overgrazing by wildlife. Wetland Degradation:

Pollution (pesticides, heavy metals, sediments, domestic sewage, and fertilizers) quality of wetland waters.

Consequences of wetlands loss Flooding

Billions of dollars spend on flooding control infrastructure over the years.

Floods continue to seriously damage the property and livelihoods of thousands of persons.

Loss of wildlife habitat Up to 45% of rare and endangered

species rely to some extent on wetlands for their survival.

Declining water quality

Historical Data: China

Yangtze River Flood (1998) Deceased: Over 3,500 Houses destroyed: 7 million People left without a home: 20

millions Farmers who lost their crops: 15

million Number of people affected: 230

millions Estimated total economic losses:

round $32,000 millions.

Historical Data: China

Causes: The increase of settlements

construction on flood-prone areas. The increase destruction of wetlands

near lakes and river to accommodate more farming.

The increase of river basin deforestation.

Solutions: Wetland restoration. Stopping deforestation.

Historical Data: USA

In the 1600’s, over 200 million acres of wetlands existed in the lower 48 states.

In the mid-1970’s, only 99 million acres remained .

A loss of approximately 54% of the original acreage.

Historical Data: USA

Causes of wetlands loss from the mid-1950’s to the mid-1970’s:

87%: agricultural conversion 8%: urban development 5%: other development

Historical Data: USA

Per-State Data: California & Iowa — over 90% of

original wetlands. Nebraska — over 90% of wetlands in

the Rainwater Basin. Mississippi — 80% of original bottom

land hardwood forests. Louisiana — loses 30,000 to 40,000

acres of coastal wetlands each year. Michigan, Minnesota, Louisiana, North

Dakota, and Connecticut — lost over 50% of their original wetlands.

Historical Data: USA

Boston, Massachusetts — Protecting the Wetlands around Charles River saves around $17 million on flood control infrastructure, according to a study.

Harnessing Technology for Wetlands Preservation Using Remote Sensing and

Digital Terrain Modeling we can provide scientists with more powerful tools to study Wetlands in their current state as well as their changes through time.

Remote Sensing

The measurement or acquisition of information of an object or phenomenon by a recording device from a distance.

Benefits for Wetlands Study Remote sensing offers a synoptic

view of the spatial distribution and dynamics of hydrological phenomena, often unattainable by traditional ground surveys.

Most hydrological processes are dynamic. Therefore, they require frequent observation.

Digital Terrain Modeling The study of ground-surface relief

and pattern using computer tools.

Terrain topography is represented by a square-grid array of terrain heights, known as Digital Elevation Maps (DEMs).

Topographic attributes can be computed from digital terrain models.

Topographic Attributes obtainable from DEMsAltitudeUpslope heightAspect Slope Upslope slope Dispersal slopeCatchment slopeUpslope areaDispersal areaCatchment area

Specific catchment areaFlow path lengthUpslope lengthDispersal lengthCatchment lengthProfile curvaturePlan curvatureTangential curvature Elevation percentile

Information obtained from topographic attributesclimatevegetationpotential energysolar insolationevapotranspirationflora and fauna distribution and abundanceoverland and subsurface flowoverland flow attenuationflow accelerationconverging/diverging flowrunoff velocity, steady-state, and rate

precipitationtime of concentrationsoil-water contentsoil drainage ratesoil characteristicsimpedance of soil drainageland capability classgeomorphologyerosion ratesdeposition ratesediment yieldflow acceleration

Benefits for Wetlands Study Digital terrain models are basic

data pools for building comparative time series of topochronological change of terrain attributes.

Digital terrain modeling visualization tools can provide scientists with new data analysis approaches.

Proposed System Description A terrain visualization system for

Wetlands monitoring and analysis based on digital elevation maps from the Envisat earth-observation satellite, and developed with Java and OpenGL.

Features

Spatial-temporal modeling of terrain data.

Data reduction, level-of-detail rendering, and data caching.

Database integration. Flexible Viewing mechanism

allowing a great variety of visualization options.

Landmarking (3D bookmarks) Animation scripting and

recording.

Architecture

Application

1 *

TerrainModel

TerrainViewWindow

1

1

Render

Modify

11

«uses»

«uses»

«utility»TerrainViewFactory

«utility»TerrainModelFactory

Creates

Creates

«uses» ViewControls TerrainView

TerrainView

TerrainView

VirtualCamera

1

*

1

1

LightSource

1

1

1

*

TerrainModel

1

*

«utility»TerrainModelFactory

Cre

at e

s

«uses»

LandmarkAnimation

TerrainModel

TerrainModel

3DModelProvider

3DModel

DataHistory

TerrainAttributes

1

1

1

1

1

1

1

1

3DShader

1 *

3DModelProvider Data Flow

Terrain Data [Source Format]

Terrain Data [Generic Format]

Terrain Data [Downsampled Data]

Terrain Data [OpenGL Primitives]

Data Downsampling

Source Acquisition

Format Conversion

Tesselation

3DModelProviderDB-SourceReader

LocalFile-SourceReader

RemoteFile-SourceReader

DEM-Translator

TIN-Translator

«interface»DataSourceReader

GML-Translator

«interface»DataFormatTranslator

«interface»DataDownsampler

Average-Downsampler

Bicubic-Downsampler

Subsampling-Downsampler

«interface»DataModelGenerator

PolygonMesh-ModelGenerator

BezierMesh-ModelGenerator

1

1

1 1

1

1

1

1

Re

adD

ata

Re

adD

ataR

ead

Data

3DModelProvider

«uses»

DataCache

«interface»DataStorageWriter

Comments

Full pipeline required only for off-line use (local files).

Pre-computed data could available on database.

Data caching would minimize re-computation and re-downloading.

Data Request Flowchart

PrecomputedData Available?

Query Remote Source

Local or Remote Source?

Remote

Yes

Download Precomputed

Data

Query Local Source

Local

Yes

No

PrecomputedData Available?Computed

DataNo

Load Data

Data Request

Dat

abas

e

Local Storage

Store Data in Cache

Read Local Precomputed Data

Terrain Visualization capabilities

One TerrainView per window, multiple windows.

Multiple TerrainModel per view. TerrainViewFactory controls how

the multiple TerrainModels are combined (vector overlay, displacement, transparency, etc).

Each TerrainModel is rendered by its 3DShader object.

Possible TerrainView Combinations

Terrain Data Visualization Capabilities Not limited to terrain visualization. Considerable amount of

information already obtainable from DEMs.

Use 3D data visualization techniques to present terrain attributes and other aggregated data.

Can be combined with the actual 3D terrain model, or displayed on a separate window.

Possible Data Visualization Views

Additional Capabilities

Animation: Camera movement recording and

playback.

Animated TerrainModel Transition TerrainView with multiple

TerrainModels Transition controlled by Animator

object.

Additional Capabilities

Stereoscopic Rendering for Terrain and Data Visualization

3DShaders for different stereoscopic techniques.

Questions

References: A statistical approach for the analysis of the relation

between low-level performance information, the code and the environment. - Nayda G. Santiago, Diane T. Rover, Domingo Rodriguez - To appear in INFORMATION : An International Journal

Terrain Analysis: Principles and Applications, Edited by John P. Wilson and John C. Gallant. ISBN 0-471-32188-5 © 2000 John Wiley & Sons, Inc.

High Resolution Digital Terrain Models of Shallow Lake Basins – Toward Modeling Dynamics of Sedimentation for Multithematic Ecosystems Research. – Elmar Csaplovics. D. Frisch, M. Englich & M. Sester, eds, “IAPRS”, Vol 32/4, ISPRS Commisision IV Symposium on GIS - Between Vision and Applications, Stuttgartm, Germany.

References: Open Geospatial Consortium

http://www.opengeospatial.org/ LandXML

http://www.landxml.org/ JOGL Project

https://jogl.dev.java.net/ Computer Based Terrain Visualization Techniques

http://astronomy.swin.edu.au/~pbourke/modelling/terrainvis/ Data reduction in terrain modeling

http://astronomy.swin.edu.au/~pbourke/modelling/terraindata/ Remote Sensing Glossary

http://www.casde.unl.edu/vn/glossary/intro.htm Wikipedia – The Free Encyclopedia

http://www.wikipedia.org/ Wetland around the World

http://www.lethsd.ab.ca/mmh/grade5/wetlands/page3.htm Puerto Rico, Humedales

http://pr.water.usgs.gov/public/online_pubs/wsp_2425/ Los Humedales

http://cremc.ponce.inter.edu/humedales.htm Natural History – Geography – Maps – Hydrology

http://iprac.aspira.org/iprac_histnat.htm Ecosistemas de Puerto Rico

http://www.ceducapr.com/ecosistemas.htm National Wetlands Inventory

http://wetlandswms.er.usgs.gov/layer_info.html Building Wetlands

http://www.epa.gov/region02/water/wetlands/prdf.pdf