Breakthroughs in Geospatial Analysis Applied to Mountains and Fish

By Richard A. Marston


Mountain regions are significant to human activities in a variety of ways, and some of these same characteristics combine to present a non-trivial challenge to those who wish to study them using geospatial techniques.Mountains cover 52% of Asia, 36% of North America, 25% of Europe, 22% of South America, 17% of Australia, and 3% of Africa...making up in total 24% of the Earth's continental surfaces (Bridges 1990).Mountains provide water for half of the world's population (Price 2002). In semiarid and arid regions this proportion is even larger.In Wyoming, for example, only 15% of the state experiences a water surplus, with mountains supplying water to the remaining 85% of the state (Ostresh et al.1990).

In mountains are found the deepest river gorges, steepest hillslopes, and some of the world's largest and most erosive rivers.Mountains provide critical habitat for many species of wildlife, mineral deposits, timber resources, hydropower potential, plus dramatic scenery.With great expenditure of human energy, terraced agriculture turns steepland environments into productive cropland with long-term sustainability.Where principles of terrain evaluation have been ignored, human occupation of mountains leads to inevitable encounters with natural hazards: earthquakes, volcanoes, floods, slope failures, lightning, wildfires, high winds, and extremes of temperature and radiation.

Human pressures on mountain resources has led to international conflict between highland and lowland countries, perhaps most notably in south Asia where subsistence farmers in the Nepal Himalaya have been blamed (in large part incorrectly) by India and Bangladesh for flooding, sedimentation and stream channel shifting in the Ganges River Plain and Delta (e.g., see Ives and Messerli 1989).In my own research, I have used remote sensing and GIS analyses of floods and slope failures to help dispel the notion that deforestation is responsible for these hazards in the Himalayas and in the lowland countries to the south (Marston et al.1996, 1998).Because all of these attributes of mountains have distinct spatial-temporal expression, the potential remains high for application of geographic information technologies.

Recent breakthroughs in geospatial analysis have allowed earth scientists to study mountain environments in new ways.Some of this exciting work is highlighted in two newly published books: Geographic Information Science and Mountain Geomorphology, edited by Bishop and Shroder (2004); and Geographic Information Systems in Fisheries, edited by Fisher and Rahel (2004).The 14 chapters in the Bishop and Shroder book promote GIS as a "powerful enabling technology," but more attention is devoted to GIS-based analysis and modeling for extracting and generating information about process-form adjustments and space-time relationships.The book presents thorough coverage of exciting topics in the physical geography of mountains using GIScience concepts and geospatial techniques: digital terrain representation, remote sensing, geostatistics, artificial intelligence, cartography and visualization, mountain hazards, surface hydrology, snow and ice, regional climate, and tectonic geomorphology and landscape evolution. 

Some of the highest rates of erosion ever measured on our planet have been reported for mountain regions, in particular the Nanga Parbat Massif in Pakistan, by combining field data with geomorphometry of DEM data sets, remote sensing, and process modeling.Some major disasters in mountain settings could have been avoided had geospatial analyses been applied.Advances in field-based GPS (global positioning system) and remote sensing techniques, such as LIDAR (light detecting and ranging), provide a wealth of new data to be incorporated in GIS analysis of mountain regions.

Some of the major challenges posed by mountains to GIS-based numerical modeling include: 1) choosing data resolutions that capture the heterogeneity of mountain environments; 2) acquiring data that is accurately and precisely georeferenced in regions that are often remote, inaccessible and poorly monitored; 3) avoiding, reducing and removing errors in DEMs and DTMs; 4) incorporating heterogeneous and non-linear mountain processes and variables into the governing equations of existing models; 5) conducting sensitivity analyses and accuracy assessments in regions where remote sensed or modeled data may be more accurate than what can be gathered from classical field work; and 6) generating and disseminating GIS outputs in ways that are ethical and accessible to people potentially affected by the findings.These issues or ones similar to them affect GIS-based modeling everywhere, but can be exacerbated by the special conditions and constraints imposed by mountain settings.

The Geographic Information Systems in Fisheries book contains numerous examples of using GIS to describe and explain fish species distributions, individual habitat variables and overall habitat suitability in mountain streams and beyond, including lakes, reservoirs, coastal waters and the ocean.The concluding chapter makes the point that the future of GIS in fisheries will depend on obtaining environmental data more economically and integrating those data with spatially explicit population dynamic models to improve decision making about fishery resources.3-D display and analysis of habitat information remains another ongoing concern in fisheries management.Research supported by major funding is currently underway across the country government research labs, at universities and in consulting firms ...using GIS to describe, explain and predict fish abundance as a function of watershed characteristics and 2-D and 3-D depictions of stream habitat.Public pressure on federal and state agencies to protect and enhance fisheries requires development of geospatial tools to assess and predict potential habitat quality across wide ranging areas where field surveys are too expensive and too time consuming.

In mountain environments and other settings where fisheries are significant, a common need of interest to readers of Directions Magazine is the call for linking spatial and temporal analyses.This is also one of the recurrent themes explored by geographers, but developing spatio-temporal techniques has lagged.In my own research, I have sought to understand the controls on lateral migration of rivers, and the effects river instability has on river and floodplain resources.Unfortunately, current GIS representations (maps) are static, while fish are moving (as anyone who fishes knows only too well) and rivers are shifting (as engineers and land owners know only too well). The TerraSeer Space-Time Intelligence SystemTM, or STISTM, is a new platform designed to address the need of earth scientists, fisheries scientists and others working in dynamic environments.The possible business applications of STIS were discussed in an April 2004 edition of Directions Magazine. STIS offers great possibility for modeling geomorphic evolution of mountains and for modeling habitat use by fish.STIS generated maps move, which allows the user to visualize data changes through time.Spatial data (e.g., river location, fish distributions) can be displayed as maps, tables, or graphs.Moreover, it is possible to perform geostatistics over time and at any point in time.

The most difficult problem facing environmental scientists, including mountain geographers and fisheries ecologists, is to separate environmental change due to human activities from change that would have occurred without human influence.Look for GIScience and geospatial techniques to play an increasing role in resolving this question, particularly as analysis over space and time are linked through platforms such as STIS.

References Cited

Bishop, Michael P.and John F.Shroder, Jr.2004.Geographic Information Science and Mountain Geomorphology.Springer-Verlag: Chichester, UK, 486 pp.

Bridges, E.M.1990.World Geomorphology.Cambridge University Press: Cambridge, U.K., 260 pp.

Fisher, William L.and Frank J.Rahel.2004.Geographic Information Systems in Fisheries.American Fisheries Society: Bethesda, MD, 275 pp.

Ives, Jack D.and Bruno Messerli.1989.The Himalayan Dilemma: Reconciling Development and Conservation.Routledge: London, UK, 295 pp.

Marston, Richard A., Jack Kleinman and Maynard Miller.1996.Geomorphic and forest cover controls on monsoon flooding, central Nepal Himalaya.Mountain Research and Development 16 (3): 257-264.

Marston, Richard A., Maynard M.Miller and Lochan P.Devkota.1998.Geoecology and mass movement in the Manaslu-Ganesh and Langtang-Jugal Himals, Nepal.Geomorphology 26: 139-150.

Ostresh, Larry M., Richard A.Marston and Walter M.Hudson.1990.Wyoming Water Atlas. Wyoming Water development Commission: Cheyenne, WY, 124 pp.

Price, Martin F.2002.Mountains.Voyageur Press: Stillwater, MN, 72 pp.

Published Thursday, October 14th, 2004

Written by Richard A. Marston

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