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South Dakota State University

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Articles 61 - 64 of 64

Full-Text Articles in Physical and Environmental Geography

Dual Scale Trend Analysis Distinguishes Climatic From Anthropogenic Effects On The Vegetated Land Surface, K. M. De Beurs, C. K. Wright, G. M. Henebry Oct 2009

Dual Scale Trend Analysis Distinguishes Climatic From Anthropogenic Effects On The Vegetated Land Surface, K. M. De Beurs, C. K. Wright, G. M. Henebry

Natural Resource Management Faculty Publications

We present a dual scale trend analysis for characterizing and comparing two contrasting areas of change in Russia and Kazakhstan that lie less than 800 km apart. We selected a global NASA MODIS (moderate resolution imaging spectroradiometer) product (MCD43C4 and MCD43A4) at a 0.05◦ (∼5.6 km) and 500 m spatial resolution and a 16-day temporal resolution from 2000 to 2008. We applied a refinement of the seasonal Kendall trend method to the normalized difference vegetation index (NDVI) image series at both scales. We only incorporated composites during the vegetative growing season which was delineated by start of season and end …


Large Seasonal Swings In Leaf Area Of Amazon Rainforests, Ranga B. Myneni, Wenze Yang, Ramakrishna R. Nemani, Alfredo R. Huete, Robert E. Dickinson, Yuri Knyazikhin, Kamel Didan, Rong Fu, Robinson I. Negron Juarez, Sasan S. Saatchi, Hirofumi Hashimoto, Kazuhito Ichii, Nikolay V. Shabanov, Bin Tan, Piyachat Ratana, Jeffrey L. Privette, Jeffrey T. Morisette, Eric F. Vermote, David P. Roy, Robert E. Wolfe, Mark A. Friedl, Steven W. Running, Petr Votava, Nazmi El-Saleous, Sadashiva Devadiga, Yin Su, Vincent V. Salomonson Mar 2007

Large Seasonal Swings In Leaf Area Of Amazon Rainforests, Ranga B. Myneni, Wenze Yang, Ramakrishna R. Nemani, Alfredo R. Huete, Robert E. Dickinson, Yuri Knyazikhin, Kamel Didan, Rong Fu, Robinson I. Negron Juarez, Sasan S. Saatchi, Hirofumi Hashimoto, Kazuhito Ichii, Nikolay V. Shabanov, Bin Tan, Piyachat Ratana, Jeffrey L. Privette, Jeffrey T. Morisette, Eric F. Vermote, David P. Roy, Robert E. Wolfe, Mark A. Friedl, Steven W. Running, Petr Votava, Nazmi El-Saleous, Sadashiva Devadiga, Yin Su, Vincent V. Salomonson

GSCE Faculty Publications

Despite early speculation to the contrary, all tropical forests studied to date display seasonal variations in the presence of new leaves, flowers, and fruits. Past studies were focused on the timing of phenological events and their cues but not on the accompanying changes in leaf area that regulate vegetation–atmosphere exchanges of energy, momentum, and mass. Here we report, from analysis of 5 years of recent satellite data, seasonal swings in green leaf area of ~25% in a majority of the Amazon rainforests. This seasonal cycle is timed to the seasonality of solar radiation in a manner that is suggestive of …


A Historical Geography Of Lake Kampeska In The City Of Watertown, South Dakota, Joanita M. Kant Jan 2007

A Historical Geography Of Lake Kampeska In The City Of Watertown, South Dakota, Joanita M. Kant

Geography Faculty Publications

Many alterations in the hydrology of Lake Kampeska began with the arrival of masses of Anglo settlers in the 1870s. Why the lake has been altered is a complex issue linked to various natural physical processes which would have occurred even without the introduction of those settlers into the ecosystem. Those processes include weather, climate, sedimentation rates, lakebank erosion, chemical and mineral transport from soils, and flooding, among others. Besides those natural physical processes, mankind’s cultural processes have been at work. Disturbances in the lake’s hydrology are linked to land use changes associated with cultural values, such as the introduction …


Fire-Induced Albedo Change And Its Radative Forcing At The Surface In Northern Austrailia, Y. Jin, David P. Roy Jul 2005

Fire-Induced Albedo Change And Its Radative Forcing At The Surface In Northern Austrailia, Y. Jin, David P. Roy

GSCE Faculty Publications

This paper investigates the impact of fire on surface albedo and the associated radiative forcing over 56% of continental Australia encompassing the fire-prone northern tropical savanna. Fire-affected areas and albedos are derived for the 2003 fire season using daily Moderate Resolution Imaging Spectroradiometer (MODIS) surface reflectance data. Near-infrared and total shortwave albedos are observed to generally decrease after fire occurrence. Regionally, the total shortwave albedo drops by an average of 0.024, with increasing reductions as the dry season progresses and larger reductions in grasslands than woody savannas. These fire-induced albedo changes exert a positive forcing at the surface that increases …