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

294 Ecosystem Simulation System) is outlined. We explain and illustrate the flow of information from raw Thematic Mapper imagery, 30 meter digital elevation models (DEM) and digitized soils maps through the derivation of the important model parameter fields, extraction and definition of a terrain feature (object) model of a watershed and aggregation of the parameter fields into each discrete landscape object, and the final distributed simulation and reporting of results. As an example, we illustrate the parameterization and simulation of the North Fork of Elk Creek, a 17 sq.km, experimental watershed in the Garnet Range of western Montana. This watershed is in steep mountainous topography, with relatively thin Qolluvial soils. The mainstreams trend east- west, so that the major slopes are largely north or south facing, with the exception of more complex areas in the headwaters of the basin. The vegetation is dominated by dense conifer canopies on north facing slopes and more open canopies with a grass understory on south facing slopes, although previous logging activity prior to 1960 and more recent fires have influenced the forest pattern in some locations. MODEL DESCRIPTION As mentioned above, FOREST-BGC is a stand level model of forest ecosystem processes, driven by micrometeorologic and local soil conditions. While the main products of the model (in the form we are currently operating it) are ET and NPP, a host of intermediate and parallel products are computed, including the seasonal trajectories of soil water content, leaf water potential and runoff, which are very useful for validation purposes. In this respect the modeler has the opportunity to check the internal consistancy of the model with a suite of observations and measurements that can be made in the field, and not be limited simply to ’tuning’ the model to produce proper ET and NPP output. This sets the model apart from a number of empirical regression based approaches to the problem. FOREST-BGC has been previously described in detail by Running and Coughlan (1988) and is discussed here just in sufficient detail to present RESSYS. Required input data includes daily meteorogical conditions for a base station and site specific data for the forest stand, in this case, for each hillslope or portion of a hillslope. Site specific information includes topographic, soil and canopy information, specifically the aspect and gradient of the surface, SWC, LAI and elevation. A semi- empirical model, MT-CLIM, extrapolates the base station climatic data using accepted principles of mountain meteorology by considering the elevation, aspect and gradient of the landscape units relative to the base station (Running, Nemani and Hungerford, 1987). The model calculates canopy interception, evaporation, transpiration, runoff, photosynthesis, growth and maintenance respiration. Precipitation is routed through the canopy and into the snowpack or soil water where it becomes available for root uptake. Leaf transpiration is calculated with a Penman-Monteith equation based on micrometeorologic conditions, LWP and LAI, and drives the uptake and conductance of soil water under the constraints of physiologic conductance and soil water potential terms. Canopy photosynthesis is a function of C02 diffusion gradient, a radiation and temperature controlled mesophyll C02 conductance, the canopy water vapor conductance, LAI and the daylength. Average canopy radiation is computed from Beers Law for shortwave radiation canopy extinction, with species specific physiologic parameters. Of significance to our parameterization strategy is the strong nonlinearity of FOREST-BGC under certain conditions. This tends to occur most often when one or more model parameters becomes limiting, such as the effect of soil water at the onset of moisture stress. As

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