scholarly journals Classification of Small-Scale Eucalyptus Plantations Based on NDVI Time Series Obtained from Multiple High-Resolution Datasets

2016 ◽  
Vol 8 (2) ◽  
pp. 117 ◽  
Author(s):  
Hailang Qiao ◽  
Mingquan Wu ◽  
Muhammad Shakir ◽  
Li Wang ◽  
Jun Kang ◽  
...  
Keyword(s):  
Time Series ◽  
High Resolution ◽  
Small Scale ◽  
Eucalyptus Plantations ◽  
Ndvi Time Series

"Blend-then-Index" or "Index-then-Blend": A Theoretical Analysis for Generating High-resolution NDVI Time Series by STARFM

2018 ◽  
Vol 84 (2) ◽  
pp. 65-73 ◽  
Author(s):  
Xuehong Chen ◽  
Meng Liu ◽  
Xiaolin Zhu ◽  
Jin Chen ◽  
Yanfei Zhong ◽  
...  
Keyword(s):  
Time Series ◽  
High Resolution ◽  
Theoretical Analysis ◽  
Ndvi Time Series

scholarly journals In situ quantification of supraglacial cryoconite morphodynamics using time-lapse imaging: an example from Svalbard

2011 ◽  
Vol 57 (204) ◽  
pp. 651-657 ◽  
Author(s):  
Tristram D.L. Irvine-Fynn ◽  
Jonathan W. Bridge ◽  
Andrew J. Hodson
Keyword(s):  
Time Series ◽  
High Resolution ◽  
Time Series Data ◽  
Time Lapse ◽  
Random Motion ◽  
Biologically Active ◽  
Series Data ◽  
Small Scale ◽  
Meteorological Forcing ◽  
Ice Surface

AbstractThere is growing recognition of the significance of biologically active supraglacial dust (cryoconite) for glacial mass balance and ecology. Nonetheless, the processes controlling the distribution, transport and fate of cryoconite particles in the glacial system remain somewhat poorly understood. Here, using a 216 hour time series of plot-scale (0.04 m2) images, we quantify the small-scale dynamics of cryoconite on Longyearbreen, Svalbard. We show significant fluctuations in the apparent cryoconite area and dispersion of cryoconite over the plot, within the 9 day period of observations. However, the net movement of cryoconite across the ice surface averaged only 5.3 mm d−1. High-resolution measurements of cryoconite granule motion showed constant, random motion but weak correlation with meteorological forcing factors and no directional trends for individual particle movement. The high-resolution time-series data suggest that there is no significant net transport of dispersed cryoconite material across glacier surfaces. The areal coverage and motion of particles within and between cryoconite holes appears to be a product of differential melting leading to changes in plot-scale microtopography, local meltwater flow dynamics and weather-dependent events. These subtle processes of cryoconite redistribution may be significant for supraglacial albedo and have bearing on the surface energy balance at the glacier scale.

A rationale for using local and regional point rainfall data for design and analysis of urban storm drainage systems

1998 ◽  
Vol 37 (11) ◽  
pp. 7-14 ◽  
Author(s):  
P. S. Mikkelsen ◽  
H. Madsen ◽  
K. Arnbjerg-Nielsen ◽  
H. K. Jørgensen ◽  
D. Rosbjerg ◽  
...  
Keyword(s):  
Time Series ◽  
High Resolution ◽  
Regional Distribution ◽  
Regional Analysis ◽  
Rainfall Data ◽  
Annual Rainfall ◽  
Small Scale ◽  
Sampling Errors ◽  
Actual Length ◽  
Geographical Variations

The Danish measuring network for high-resolution rainfall data consists of approximately 70 tipping bucket rain gauges of which 41 have been operated for more than 10 years. The gauges are separated by one to 300 km and cover an area of 43,000 km2. Significant geographical variations of extreme rainfall characteristics have been observed. Part of these variations can be explained by correlation with the mean annual rainfall and the existence of a metropolitan effect in the Greater Copenhagen area. The remaining variation may be attributed to sampling errors and small-scale spatial variations close to the gauges. Engineering methodologies all require rain data of some kind, ranging from design storms based on idf-curves for use in simple calculations to high-resolution time series for use in detailed simulation studies. A comprehensive regional analysis was carried out to account for the geographical variation and to improve estimation for large return periods exceeding the actual length of the measured time series. Ideally, rainfall data used as input to urban drainage calculations should always be based on regional rain information. Regional design storms can be made readily available based on theory developed in this study. However, a satisfactory framework for generating synthetic rain series from regional rain information is not yet available. Thus, there will still be a need for using historical rain series in the near future. To improve the basis for choosing representative historical rain series all the Danish gauges have been classified according to their deviations from the regional distribution.

scholarly journals Mapping Mediterranean Forest Plant Associations and Habitats with Functional Principal Component Analysis Using Landsat 8 NDVI Time Series

2020 ◽  
Vol 12 (7) ◽  
pp. 1132 ◽  
Author(s):  
Simone Pesaresi ◽  
Adriano Mancini ◽  
Giacomo Quattrini ◽  
Simona Casavecchia
Keyword(s):  
Principal Component Analysis ◽  
Time Series ◽  
Principal Component ◽  
Component Analysis ◽  
Functional Principal Component Analysis ◽  
Mediterranean Forest ◽  
Plant Associations ◽  
Functional Principal Component ◽  
Ndvi Time Series

The classification of plant associations and their mapping play a key role in defining habitat biodiversity management, monitoring, and conservation strategies. In this work we present a methodological framework to map Mediterranean forest plant associations and habitats that relies on the application of the Functional Principal Component Analysis (FPCA) to the remotely sensed Normalized Difference Vegetation Index (NDVI) time series. FPCA, considering the chronological order of the data, reduced the NDVI time series data complexity and provided (as FPCA scores) the main seasonal NDVI phenological variations of the forests. We performed a supervised classification of the FPCA scores combined with topographic and lithological features of the study area to map the forest plant associations. The supervised mapping achieved an overall accuracy of 87.5%. The FPCA scores contributed to the global accuracy of the map much more than the topographic and lithological features. The results showed that (i) the main seasonal phenological variations (FPCA scores) are effective spatial predictors to obtain accurate plant associations and habitat maps; (ii) the FPCA is a suitable solution to simultaneously express the relationships between remotely sensed and ecological field data, since it allows us to integrate these two different perspectives about plant associations in a single graph. The proposed approach based on the FPCA is useful for forest habitat monitoring, as it can contribute to produce periodically detailed vegetation-based habitat maps that reflect the “current” status of vegetation and habitats, also supporting the study of plant associations.

scholarly journals Land Cover Classification of an Area Susceptible to Landslides Using Random Forest and NDVI Time Series Data

2020 ◽  
Author(s):  
Tatiana Dias Tardelli Uehara ◽  
Anderson Reis Soares ◽  
Renata Pacheco Quevedo ◽  
Thales Sehn Korting ◽  
Leila Maria Garcia Fonseca ◽  
...  
Keyword(s):  
Time Series ◽  
Random Forest ◽  
Land Cover ◽  
Time Series Data ◽  
Land Cover Classification ◽  
Series Data ◽  
Ndvi Time Series
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