Proceedings of the Symposium on Global and Environmental Monitoring: Proceedings of the Symposium on Global and Environmental Monitoring

Bibliographic data

Multivolume work

Persistent identifier:: 856665355

Title:: Proceedings of the Symposium on Global and Environmental Monitoring

Sub title:: techniques and impacts ; September 17 - 21, 1990, Victoria Conference Centre, Victoria, British Columbia, Canada

Year of publication:: 1990

Place of publication:: Victoria, BC

Publisher of the original:: [Verlag nicht ermittelbar]

Identifier (digital):: 856665355

Language:: English

Document type:: Multivolume work

Volume

Persistent identifier:: 856669164

Title:: Proceedings of the Symposium on Global and Environmental Monitoring

Sub title:: techniques and impacts; September 17 - 21, 1990, Victoria Conference Centre, Victoria, British Columbia, Canada

Scope:: XIV, 912 Seiten

Year of publication:: 1990

Place of publication:: Victoria, BC

Publisher of the original:: [Verlag nicht ermittelbar]

Identifier (digital):: 856669164

Illustration:: Illustrationen, Diagramme, Karten

Signature of the source:: ZS 312(28,7,1)

Language:: English

Usage licence:: Attribution 4.0 International (CC BY 4.0)

Editor:: International Society for Photogrammetry and Remote Sensing, Commission of Photographic and Remote Sensing Data

Publisher of the digital copy:: Technische Informationsbibliothek Hannover

Place of publication of the digital copy:: Hannover

Year of publication of the original:: 2016

Document type:: Volume

Collection:: Earth sciences

Chapter

Title:: [WA-5 WATER RESOURCES]

Document type:: Multivolume work

Structure type:: Chapter

Chapter

Title:: Spatial Modelling of Forest Watershed Processes. Lawrence Band, Steven Running, Joseph Coughlan, David Peterson, Jennifer Dungan,

Document type:: Multivolume work

Structure type:: Chapter

295 these conditions are generally the situations we are most interested in, it is important to efficiently parameterize the model to limit numerical inaccuracy and to allow detailed investigation of the resulting system behaviour. Because we are aggregating continuous parameter fields into the parameter sets for each discrete landscape unit (hillslope in this case) it is important to avoid aggregation over significantly different environments (such as north and south facing slopes). Besides filtering out the extreme responses of the system, the use of mean parameter values may yield significantly biased model results relative to the true mean system response in the presence of strong nonlinearity. While more linearized models would appear to avoid this problem, we point out that natural systems tend to be very nonlinear, hence the nonlinear form of FOREST-BGC and the important constraints on model parameterization in terms of the admissible variance or range of parameter values within a landscape unit. DISTRIBUTED PARAMETERIZATION - RESSYS Geographic Information Processing The prepartion of the landscape unit template and estimation of the model parameters for each hillslope involves a combination of digital terrain analysis, remote sensing, and geographic information processing. RESSYS is an integrated data and simulation system that is currently under construction to accomplish the data preprocessing, model parameterization, model execution and output production (figure 1). As can be seen a substantial amount of the computation and analysis is devoted to raw data processing and combination. The results of these processes are the assembly of the fixed site information for each landscape unit. This information is stored in a cartridge file (table 1, figure 1), which in combination with the seasonal base station meteorological information is fed info MT-CLIM which derives additional micrometeorlogical parameters for FOREST-BGC. The cartridge file acts as the parameter representation of the landscape. As alternative landscape objects can be defined to describe the landscape, such as composite watersheds, larger or smaller hillslopes, any cartridge file can be pulled out and another cartridge file inserted to model another representation of the landscape. This provides additional flexibility for exploration of efficient parameterization strategies. Digital Terrain Analysis A 30 meter resolution DEM (figure 2) was used to compute surface gradient and aspect, and to automatically extract the stream network and the set of hillslopes comprising the North Fork of Elk Creek. Band (1986, 1989) and Lammers and Band (1990) have described these steps in detail and they are not repeated here for the sake of brevity. At present we use a representation of the North Fork by seven stream links (the stretches of channel between stream junctions or a stream source and a junction) and fourteen hillslopes (two hillslopes draining into the two banks of each stream link, see figure 3.) Our methods allow the flexible decomposition of the watershed into a wide number of hillslopes, from just the mainstream up through the smallest tributaries. These different watershed representations would be stored as different cartridge files, but we will not discuss the effects of different watershed representation here as we use the fourteen hillslope watershed just for illustrative purposes. The gradient and aspect of each hillslope is retrieved by computing the resultant vector from the set of surface unit normal vectors of each DEM pixel in each hillslope. This effectively models each hillslope as a facet with the spherical mean

Access restriction

Copyright

fullscreen: Proceedings of the Symposium on Global and Environmental Monitoring (Part 1)

Multivolume work

Volume

Chapter

Chapter

Table of contents

Cite and reuse

Volume

Chapter

Image

Image fragment

Citation links

Citation recommendation