Download or read book Implementation of Digital Terrain Analysis to Capture the Effects of Wind Redistribution in Spatial Snow Modeling written by Adam Winstral and published by . This book was released on 1999 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spatial Patterns in Catchment Hydrology written by Rodger Grayson and published by CUP Archive. This book was released on 2001-08-06 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: Describes use of observed patterns in understanding and modelling hydrological response, for researchers and graduate students.
Download or read book Proceedings of the Western Snow Conference written by and published by . This book was released on 2003 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Digital Terrain Modelling written by Robert Joseph Peckham and published by Springer Science & Business Media. This book was released on 2007-10-12 with total page 327 pages. Available in PDF, EPUB and Kindle. Book excerpt: This publication is the first book on the development and application of digital terrain modeling for regional planning and policy support. It is a compilation of research results by international research groups at the European Commission’s Joint Research Centre, providing scientific support to the development and implementation of EU environmental policy. This practice-oriented book is recommended reading for practising environmental modelers and GIS experts working on regional planning and policy support applications.
Download or read book Digital Terrain Modeling written by Zhilin Li and published by CRC Press. This book was released on 2004-11-29 with total page 337 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by experts, Digital Terrain Modeling: Principles and Methodology provides comprehensive coverage of recent developments in the field. The topics include terrain analysis, sampling strategy, acquisition methodology, surface modeling principles, triangulation algorithms, interpolation techniques, on-line and off-line quality control in data a
Download or read book Hydrology in Mountain Regions written by Danny Marks and published by . This book was released on 2009 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Environmental Applications of Digital Terrain Modeling written by John P. Wilson and published by John Wiley & Sons. This book was released on 2018-02-15 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt: A digital elevation model (DEM) is a digital representation of ground surface topography or terrain. It is also widely known as a digital terrain model (DTM). A DEM can be represented as a raster (a grid of squares) or as a vector based triangular irregular network (TIN). DEMs are commonly built using remote sensing techniques, but they may also be built from land surveying. DEMs are used often in geographic information systems, and are the most common basis for digitally-produced relief maps. The terrain surface can be described as compromising of two different elements; random and systematic. The random (stochastic) elements are the continuous surfaces with continuously varying relief. It would take an endless number of points to describe exactly the random terrain shapes, but these can be described in practice with a network of point. It is usual to use a network that creates sloping triangles or regular quadrants. This book examines how the methods and data sources used to generate DEMs and calculate land surface parameters have changed over the past 25 years. The primary goal is to describe the state-of-the-art for a typical digital terrain modeling workflow that starts with data capture, continues with data preprocessing and DEM generation, and concludes with the calculation of one or more primary and secondary land surface parameters. Taken as a whole, this book covers the basic theory behind the methods, the instrumentation, analysis and interpretation that are embedded in the modern digital terrain modeling workflow, the strengths and weaknesses of the various methods that the terrain analyst must choose among, typical applications of the results emanating from these terrain modeling workflows, and future directions. This book is intended for researchers and practitioners who wish to use DEMs, land surface parameters, land surface objects and landforms in environmental projects. The book will also be valuable as a reference text for environmental scientists who are specialists in related fields and wish to integrate these kinds of digital terrain workflows and outputs into their own specialized work environments.
Download or read book Digital Terrain Analysis in Soil Science and Geology written by Igor Florinsky and published by Academic Press. This book was released on 2012 with total page 398 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This book is the first attempt to synthesize knowledge on theory, methods, and applications of digital terrain analysis in the context of multiscale problems of soil science and geology. The content of the book is based on long-standing, interdisciplinary research of the author. The book is addressed to geomorphometrists, soil scientists, geologists, geoscientists, geomorphologists, geographers, and GIS scientists (at scholar, lecturer, and postgraduate student levels, with mathematical skills). This book is also intended for the GIS professionals in industry and research laboratories focusing on geoscientific and soil research. The book is divided into three parts. Part I represents main concepts, principles, and methods of digital terrain modeling. Part II discusses various aspects of the use of digital terrain analysis in soil science. Part III looks at applications of digital terrain modeling in geology"--
Download or read book Measurement Modeling and Remote Sensing of Snow Cover in Areas of Heterogeneous Vegetation written by David Selkowitz and published by . This book was released on 2005 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt: Numerous studies have demonstrated that vegetation canopies affect snow accumulation and ablation processes. In addition, estimates of remotely sensed snow covered area can be biased by the presence of an overlying vegetation canopy. Consequently, any attempts to measure, model, or map the distribution of snow in a region with heterogeneous vegetation cover would benefit from a more complete understanding of both the relationship between vegetation density and snow cover on the ground as well as the relationship between remotely sensed snow covered area and actual snow covered area under various vegetation densities. The research presented here explores both of these relationships. Chapter 2 describes, qualitatively and quantitatively, the relationship between canopy gap fraction (the inverse of canopy density) and snow accumulation at fine spatial scales in Glacier National Park, Montana. Gap fraction and snow cover data from two winters were compared along eight vegetation-snow transects representing a range of landscape types, including dense forest, variable density forests with openings, forest-grassland mosaics, and burned-unburned forest mosaics. The data suggest that the relationship between gap fraction and snow accumulation depends on the range of gap fraction values considered. For gap fraction values less than 40%, a significant positive linear relationship exists between gap fraction and snow accumulation. For gap fraction values between 40% and 90%, the relationship is poorly defined, most likely due to the influence of the spatial patterning of vegetation on wind scouring/deposition of snow which cannot be captured by a simple metric such as gap fraction. When gap fraction exceeds - 90%, snow cover is almost always shallow or nonexistent due to wind scouring and high solar radiation loads. The poorly defined relationship between gap fraction and snow accumulation in the range of 40-90% gap fraction is not highly problematic because this gap fraction range represents only 24% of the landscape, and the 60-90% range of gap fraction where the gap fraction-snow accumulation relationship is least pronounced represents only 5% of the landscape. The results from these vegetation-snow surveys indicate that at fine spatial scales where topographic variability is minimal, canopy density can explain a substantial portion of the variability in snow accumulation that would otherwise remain unexplained. The high variance in snow accumulation in the 60-90% gap fraction range and the relatively small sample size presented here make it unrealistic, however, to infer an optimum gap fraction for snow accumulation in Glacier National Park or anywhere else. Chapter 3 provides an assessment of methods for modeling and mapping spatiotemporal variability in snow cover in Glacier National Park. SnowModel, a relatively new physically-based snow evolution model that accounts for the influence of vegetation on snow processes, was used to simulate the spatial distribution of snow water equivalent at hourly time steps for an 850 km2 model domain in eastern Glacier National Park. The standard implementation of SnowModel uses an image of land cover type to adjust snow accumulation and ablation for the effects of vegetation. In this non-standard implementation, the model was parameterized using a weighting scheme that allowed the model to utilize a Landsat-derived image of gap fraction to adjust snow accumulation and ablation in a more precise manner than would have been possible if only land cover type information was available. In situ measurements suggest the model did a reasonable job simulating snow evolution patterns and the differences in snow evolution associated with different vegetation densities. Weaknesses in this implementation of SnowModel appear to be its tendency to overestimate snow in the easternmost portion of the model domain (where a significant rain shadow effect exists) and overestimate snow in exposed areas. Due to a lack of in situ measurements at the scale of the model output, it was not possible to conclusively determine if the incorporation of fine scale (28.5 m pixel) information on forest canopy density improved model accuracy. MODIS-derived images of binary and fractional snow covered area were also evaluated. The binary product consistently mapped a higher percentage of the study area as snow covered than the fractional product. Spatial patterns of snow covered area were similar for the MODIS-derived products and the results from the implementation of SnowModel. Unfortunately, the remotely sensed snow covered area products could not be used to evaluate the model's treatment of snow evolution under different vegetation conditions because gap fraction influences the mapping of snow covered area for the remotely sensed products. Understanding how remotely sensed estimates of snow covered area are influenced by gap fraction density will hopefully allow for these products to be used as a validation tool for spatially distributed model results in areas of heterogeneous vegetation in the future.
Download or read book Digital Terrain Modeling written by Naser El-Sheimy and published by Artech House Publishers. This book was released on 2005 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Here's the first truly comprehensive guide to digital terrain modeling that provides you with a thorough, mathematically rigorous treatment of DTM generation, manipulation, and analysis techniques and applications in a single volume. It describes photogrammetric data capture, direct georeferencing systems, LIDAR, IFSAR and other data acquisition techniques, and explains how to determine the most appropriate DTM generation technique for any given project. You find a detailed treatment of DTM data structures, including storage and compression techniques for gridded data, as well as data filtering and smoothing procedures.
Download or read book Digital Terrain Analysis and Simulation Modeling to Assess Spatial Variabilty of Soil Water Balance and Crop Production written by Bruno Basso and published by . This book was released on 2000 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Digital Terrain Analysis Third Edition written by Igor Florinsky and published by Elsevier. This book was released on 2025-01-01 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Digital Terrain Analysis, Third Edition, synthesizes the knowledge on methods and applications of digital terrain analysis and geomorphometry in the context of multi-scale problems in soil science, geology, and polar research. Divided into four parts, the book examining the main concepts, principles, and methods of digital terrain modeling; methods for analysis, modeling, and mapping of spatial distribution of soil properties; techniques for recognition, analysis, and interpretation of topographically manifested geological features; and finally the brand new fourth part investigates polar research. Digital Terrain Analysis, Third Edition, is an updated and revised edition, providing both a theoretical and methodological basis for understanding and applying geographical modeling techniques. Presents an integrated and unified view of digital terrain analysis in both soil science and geology Includes a rigorous description of the mathematical principles of digital terrain analysis Provides both a theoretical and methodological basis for understanding and applying geographical modeling Adds a brand new section on Digital Terrain Modeling in polar research, as well as updated information, methods and figures from previous edition chapters
Download or read book Snow Accumulation Distribution Inferred from Time lapse Photography and Simple Modelling written by and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The spatial and temporal distribution of snow accumulation is complex and significantly influences the hydrological characteristics of mountain catchments. Many snow redistribution processes, such as avalanching, slushflow or wind drift, are controlled by topography, but their modelling remains challenging. In situ measurements of snow accumulation are laborious and generally have a coarse spatial or temporal resolution. In this respect, time-lapse photography shows itself as a powerful tool for collecting information at relatively low cost and without the need for direct field access. In this paper, the snow accumulation distribution of an Alpine catchment is inferred by adjusting a simple snow accumulation model combined with a temperature index melt model to match the modelled melt-out pattern evolution to the pattern monitored during an ablation season through terrestrial oblique photography. The comparison of the resulting end-of-winter snow water equivalent distribution with direct measurements shows that the achieved accuracy is comparable with that obtained with an inverse distance interpolation of the point measurements. On average over the ablation season, the observed melt-out pattern can be reproduced correctly in 93% of the area visible from the fixed camera. The relations between inferred snow accumulation distribution and topographic variables indicate large scatter. However, a significant correlation with local slope is found and terrain curvature is detected as a factor limiting the maximal snow accumulation.
Download or read book Advances in Digital Terrain Analysis written by Qiming Zhou and published by Springer. This book was released on 2009-09-03 with total page 462 pages. Available in PDF, EPUB and Kindle. Book excerpt: Terrain analysis has attracted research studies from geographers, surveyors, engineers and computer scientists. The contributions in this book represent the state-of-the-art of terrain analysis methods and techniques in areas of digital representation, morphological and hydrological models, uncertainty and applications of terrain analysis. The book will appeal to postgraduate and senior undergraduate students who take advanced courses in GIS and geographical analysis.
Download or read book The Effects of Digital Elevation Model Resolution on the Calculation and Predictions of Topographic Wetness Indices written by and published by . This book was released on 2011 with total page 145 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the largest exports in the Southeast U.S. is forest products. Interest in biofuels using forest biomass has increased recently, leading to more research into better forest management BMPs. The USDA Forest Service, along with the Oak Ridge National Laboratory, University of Georgia and Oregon State University are researching the impacts of intensive forest management for biofuels on water quality and quantity at the Savannah River Site in South Carolina. Surface runoff of saturated areas, transporting excess nutrients and contaminants, is a potential water quality issue under investigation. Detailed maps of variable source areas and soil characteristics would therefore be helpful prior to treatment. The availability of remotely sensed and computed digital elevation models (DEMs) and spatial analysis tools make it easy to calculate terrain attributes. These terrain attributes can be used in models to predict saturated areas or other attributes in the landscape. With laser altimetry, an area can be flown to produce very high resolution data, and the resulting data can be resampled into any resolution of DEM desired. Additionally, there exist many maps that are in various resolutions of DEM, such as those acquired from the U.S. Geological Survey. Problems arise when using maps derived from different resolution DEMs. For example, saturated areas can be under or overestimated depending on the resolution used. The purpose of this study was to examine the effects of DEM resolution on the calculation of topographic wetness indices used to predict variable source areas of saturation, and to find the best resolutions to produce prediction maps of soil attributes like nitrogen, carbon, bulk density and soil texture for low-relief, humid-temperate forested hillslopes. Topographic wetness indices were calculated based on the derived terrain attributes, slope and specific catchment area, from five different DEM resolutions. The DEMs were resampled from LiDAR, which is a laser altimetry remote sensing method, obtained from the USDA Forest Service at Savannah River Site. The specific DEM resolutions were chosen because they are common grid cell sizes (10m, 30m, and 50m) used in mapping for management applications and in research. The finer resolutions (2m and 5m) were chosen for the purpose of determining how finer resolutions performed compared with coarser resolutions at predicting wetness and related soil attributes. The wetness indices were compared across DEMs and with each other in terms of quantile and distribution differences, then in terms of how well they each correlated with measured soil attributes. Spatial and non-spatial analyses were performed, and predictions using regression and geostatistics were examined for efficacy relative to each DEM resolution. Trends in the raw data and analysis results were also revealed.
Download or read book The MAP Program written by Roger H. Twito and published by . This book was released on 1987 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Improving Snow Deposition Magnitude and Heterogeneity Using Historic Snow Patterns in the California USA Sierra Nevada written by Justin Matthew Pflug and published by . This book was released on 2021 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mountainous snow-covered landscapes in the Western United States behave like natural reservoirs, storing water during cold winter periods and sustaining snowmelt-driven streamflow vital for agriculture, municipalities, hydropower generation, and local ecosystems. In these regions, the timing and duration of spring snowmelt, and the resulting streamflow, are driven by both total snow volume and its spatial distribution across the landscape. Yet, our ability to model mountainous snow magnitude at hillslope spatial scales ( 100 m resolution) is hindered by uncertainties in snowfall and misrepresentations of snow processes like wind redistribution, preferential deposition, and avalanching. Fortunately, snow deposition in mountainous landscapes is driven by the interaction between prevailing snowstorm characteristics and static features like terrain and vegetation, often resulting in interannually repeatable snow distribution patterns. This dissertation investigated the value of repeatable snow patterns in the California Sierra Nevada using an unprecedented collection of ground-based, airborne, and satellite-based snow observations. We investigated how historic information about snow distribution and real-time snowpack observations could be combined to infer snow magnitude at hillslope spatial scales using both statistical and numerical modeling approaches. In Chapter 2, we began by calculating snow depth pattern repeatability at 25 m spatial resolution using a set of 47 airborne lidar snow depth observations in the Upper Tuolumne river watershed spanning water-years 2013 through 2019. Our results showed that normalized snow depth patterns between observation dates with similar relative amounts of snow accumulation and depletion, similar seasonal timing, and similar snow extents, were well-correlated in space (median r 0.84). This pattern repeatability could be used to infer watershed-scale snow depth distribution using the relationship between a snow depth pattern from a different year and a small subset of real-time observations covering
