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

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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

Spatial Modelling of Forest Watershed Processes Lawrence Band, Ramakrishna Nemani, University of Toronto Steven Running, Joseph Coughlan, University of Montana David Peterson, Jennifer Dungan, NASA/Ames Research Center ABSTRACT A geographic information processing and modelling system is under construction for the simulation of forest watershed processes over a range of spatial scales. The system organizes all environmental information by a formal landscape feature model, utilizing the hillslopes and drainage lines of a watershed as the spatial framework for storage and manipulation of model parameters. Parameters are derived from a combination of remotely sensed imagery, digital terrain data, digitized soil maps and base station meteorologic data. Simulation is distributed over the watershed area by seperately parameterizing and simulating hydroecologic processes for each hillslope. INTRODUCTION We describe a system for automating the spatial data handling, model parameterization and simulation of forest ecosystem processes within watersheds of varying scales. We link an existing ecosystem model, FOREST- BGC, which simulates the cycles of water, carbon and nitrogen between soil, canopy and atmosphere (Running and Coughlan, 1988), with a set of algorithms specifically designed to stratify and manipulate spatial data in a watershed. The system is designed to first identify and extract all stream channels and hillslopes in a watershed as data objects, and build a hierarchical database in which the data objects are explicitly defined in relation to all other objects in the natural watershed hierarchy. The data model used here includes all hillslopes and stream channel links as the most primitive objects, from which composite objects of larger hillslopes, subcatchments and watersheds can be easily formed by use of a formal geomorphic model of drainage basins. FOREST-BGC simulates the net primary productivity (NPP) and évapotranspiration (ET) of a forest stand. Extensive sensitivity analysis of FOREST- BGC has shown the most important parameters are net radiation (R), atmospheric vapor pressure deficit (VPD), canopy leaf area index (LAI), air temperature (T) and the available soil water capacity (SWC). In mountainous environments, the close coupling of these parameters with the topography suggests that use of hillslope objects to spatially aggregate the parameters results in lower internal parameter variance and higher between unit (hillslope) parameter variance. The relatively conservative range of net radiation over a hillslope facet compared to the range expected over arbitrarily located grid cells (such as AVHRR pixels) allows a much greater discrimination of well expressed and observable landscape patterns that otherwise may be filtered out. In addition, hillslopes, stream channels and watersheds are functional hydrologic units as sources and conveyors of water, and allow aggregation into larger functional units, unlike arbitrarily located grid cells. In order to discriminate parameter values between hillslopes, it is necessary that parameters be estimated at significantly higher spatial resolution than that of the hillslopes. Consequently, high resolution imagery and terrain data must be used to produce initial parameter fields, from which the hillslope parameterization is developed. In this paper, RESSYS (Regional

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