Physical and Environmental Geography | Open Access Articles

Sequias En El Sur De La Peninsula De Yucatan: Analisis De La Variabilidad Anual Y Estacional De La Precipitacion (Droughts In The Southern Yucatan Peninsula: Analysis Of The Annual And Seasonal Precipitation Variability), Sofia Mardero, Elsa Nickl, Birgit Schmook, Laura Schneider, John Rogan, Zachary Christman, Deborah Lawrence

Zachary Christman

Paper is in Spanish. English abstract: This study analyzes the spatial and temporal variability of precipitation across the Southern Yucatán Peninsula in Mexico, addressing the anomalies and trends of annual and seasonal precipitation as well as the occurrence of meteorological droughts, using rainfall data from nine weather stations during the period 1953-2007. Linear regression in the annual and seasonal rainfall were used to analyze the increase or decrease in precipitation trends over this period. Precipitation anomalies enabled the evaluation of the stability, deficit, or surplus of precipitation for each year or season, and a quintile method was used to …

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Prototype For Monitoring And Forecasting Fall Foliage Coloration In Real Time From Satellite Data, Xiaoyang Zhang, Mitchell D. Goldberg, Yunyue Yu

Xiaoyang Zhang

While determining vegetation phenology from the time series of historical satellite data has been widely investigated throughout the last decade, little effort has been devoted to real-time monitoring and short-term forecasting. The latter is more important for numerical weather modeling, ecosystem forecasting, forest and crop management, and health risk warning. In this study we developed a prototype approach for the real-time monitoring and short-term forecasting of fall foliage status (including low coloration, moderate coloration, near-peak coloration, peak coloration, and post-peak coloration) using temporal satellite observations. The algorithm combined the climatology of vegetation phenology and temporally available satellite observations to establish …

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Interannual Variations And Trends In Global Land Surface Phenology Derived From Enhanced Vegetation Index During 1982–2010, Xiaoyang Zhang, Bin Tan, Yunyue Yu

Xiaoyang Zhang

Land surface phenology is widely retrieved from satellite observations at regional and global scales, and its long-term record has been demonstrated to be a valuable tool for reconstructing past climate variations, monitoring the dynamics of terrestrial ecosystems in response to climate impacts, and predicting biological responses to future climate scenarios. This study detected global land surface phenology from the advanced very high resolution radiometer (AVHRR) and the Moderate Resolution Imaging Spectroradiometer (MODIS) data from 1982 to 2010. Based on daily enhanced vegetation index at a spatial resolution of 0.05 degrees, we simulated the seasonal vegetative trajectory for each individual pixel …

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Daily Modis 500 M Reflectance Anisotropy Direct Broadcast (Db) Products For Monitoring Vegetation Phenology Dynamics, Yanmin Shuai, Crystal Schaaf, Xiaoyang Zhang, Alan Strahler, David P. Roy, Jeffery Morisette, Zhuosen Wang, Joanne Nightingale, Jaime Nickerson, Andrew D. Richardson, Donghui Xie, Jindi Wang, Xiaowen Li, Kathleen Strabala, James E. Davies

Xiaoyang Zhang

Land surface vegetation phenology is an efficient bio-indicator for monitoring ecosystem variation in response to changes in climatic factors. The primary objective of the current article is to examine the utility of the daily MODIS 500 m reflectance anisotropy direct broadcast (DB) product for monitoring the evolution of vegetation phenological trends over selected crop, orchard, and forest regions. Although numerous model-fitted satellite data have been widely used to assess the spatio-temporal distribution of land surface phenological patterns to understand phenological process and phenomena, current efforts to investigate the details of phenological trends, especially for natural phenological variations that occur on …

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A Cross Comparison Of Spatiotemporally Enhanced Springtime Phenological Measurements From Satellites And Ground In A Northern U.S. Mixed Forest, Liang Liang, Mark D. Schwartz, Zhuosen Wang, Feng Gao, Crystal B. Schaaf, Bin Tan, Jeffrey T. Morisette, Xiaoyang Zhang

Xiaoyang Zhang

Cross comparison of satellite-derived land surface phenology (LSP) and ground measurements is useful to ensure the relevance of detected seasonal vegetation change to the underlying biophysical processes. While standard 16-day and 250-m Moderate Resolution Imaging Spectroradiometer (MODIS) vegetation index (VI)-based springtime LSP has been evaluated in previous studies, it remains unclear whether LSP with enhanced temporal and spatial resolutions can capture additional details of ground phenology. In this paper, we compared LSP derived from 500-m daily MODIS and 30-m MODIS-Landsat fused VI data with landscape phenology (LP) in a northern U.S. mixed forest. LP was previously developed from intensively observed …

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Full-Text Articles in Physical and Environmental Geography

Zachary Christman

Prototype For Monitoring And Forecasting Fall Foliage Coloration In Real Time From Satellite Data, Xiaoyang Zhang, Mitchell D. Goldberg, Yunyue Yu

Xiaoyang Zhang

Interannual Variations And Trends In Global Land Surface Phenology Derived From Enhanced Vegetation Index During 1982–2010, Xiaoyang Zhang, Bin Tan, Yunyue Yu

Xiaoyang Zhang

Xiaoyang Zhang

A Cross Comparison Of Spatiotemporally Enhanced Springtime Phenological Measurements From Satellites And Ground In A Northern U.S. Mixed Forest, Liang Liang, Mark D. Schwartz, Zhuosen Wang, Feng Gao, Crystal B. Schaaf, Bin Tan, Jeffrey T. Morisette, Xiaoyang Zhang

Xiaoyang Zhang