Ferrous VCI Papers - KPR ADCOR INC VCI Corrosion Protection Products
Presentación Índice de Sequía Agrícola VCI (Vegetation Condition Index)
description
Transcript of Presentación Índice de Sequía Agrícola VCI (Vegetation Condition Index)
Drought index based on remote sensing, using ’R’ and’raster’ package, in B́ıo-B́ıo region, Chile.
Francisco Zambrano Bigiarini
INIA
7 de diciembre de 2012
[email protected] (INIA) Drought index based en RS using R 7 de diciembre de 2012 1 / 35
Outline
1 General Review
2 Vegetation Condition Index (VCI)
3 Preliminary Results
4 Recommendations
[email protected] (INIA) Drought index based en RS using R 7 de diciembre de 2012 2 / 35
General Review
Drought and its Classification
DefinitionThere is not a precise definition of drought
• ’drought means a sustained, extended deficiency in precipitation’ (WMO,1986)
• ’the percentage of years when crops fail from the lack of moisture’ (FAO, 1983)
• .....
Depending on the field/context, a drought event can be
1 Meteorological: drought is usually based on long-term precipitation departures fromnormal.
2 Hydrological: drought refers to deficiencies in surface and subsurface water supplies.
3 Agricultural: drought occurs when there is insufficient soil moisture to meet the needs of aparticular crop at a particular time.
[email protected] (INIA) Drought index based en RS using R 7 de diciembre de 2012 4 / 35
General Review
Why use remote sensing for drought assessment?
Advantages
• Local and global monitoring.
• Spatial and temporal assesment.
• Widly used in the last two decades for monitoring vegetationcondition.
• A good choice for a developing country, which have insufficientdensity of weather stations
• Since 2000 we have data with highly temporal resolution and mediumspatial resolution from sensor MODIS.
[email protected] (INIA) Drought index based en RS using R 7 de diciembre de 2012 5 / 35
General Review
Normalized Difference Vegetation Index (NDVI)
In short
It is a measure of the vegetation health.
NDV I =NIR− V IS
NIR+ V IS(1)
−1 ≤ NDV I ≤ 1
But in agricultural, its value is abovezero.
0 − > poor vegetation condition.1 − > good vegetation condition
[email protected] (INIA) Drought index based en RS using R 7 de diciembre de 2012 6 / 35
General Review
Informatic tools for remote sensing and GIS
Wide variety of softwares
• Propietary (Very high cost applications): ENVI, ERDAS, ESRI, Matlab
• OpenSource: GRASS GIS, QGIS, ILWISS, R
What is needed?
• Procesing a huge amount of data raster.
• Perform sophisticated data analysis and graphics.
• Interact with other software.
• Work efficiently
[email protected] (INIA) Drought index based en RS using R 7 de diciembre de 2012 7 / 35
Vegetation Condition Index (VCI)
VCI features (Kogan,1994)
• Derived from the NDVI
• Was designed to separate the weather related component of NDVIfrom ecological factors.
• Reflects the spatial and temporal vegetation variability.
• Its a scaling of the NDVI between its maximum and minimum.
• Has excellent ability to detect drought and to mesure time of itsonset, intensity, duration, and impact on vegetation.
• Its value goes between 0 and 100 %
V CIi = 100NDV Ii −NDV Imin
NDV Imax −NDV Imin(2)
[email protected] (INIA) Drought index based en RS using R 7 de diciembre de 2012 9 / 35
Vegetation Condition Index (VCI)
Calculation example for a single pixel
1 We use data from MODIS sensor (2000-2012), 16 days composite.
2 Firstly we need an smoothed NDVI. (LOWESS (Cleveland,1981))
[email protected] (INIA) Drought index based en RS using R 7 de diciembre de 2012 10 / 35
Vegetation Condition Index (VCI)
Calculation example for a single pixel
[email protected] (INIA) Drought index based en RS using R 7 de diciembre de 2012 11 / 35
Vegetation Condition Index (VCI)
Calculation example for a single pixel
[email protected] (INIA) Drought index based en RS using R 7 de diciembre de 2012 12 / 35
Vegetation Condition Index (VCI)
NDVI and VCI, 2000-2012
[email protected] (INIA) Drought index based en RS using R 7 de diciembre de 2012 13 / 35
Preliminary Results
Whole region
[email protected] (INIA) Drought index based en RS using R 7 de diciembre de 2012 15 / 35
Preliminary Results
Whole region
[email protected] (INIA) Drought index based en RS using R 7 de diciembre de 2012 16 / 35
Preliminary Results
Spatial and temporal evolution in a drought season
[email protected] (INIA) Drought index based en RS using R 7 de diciembre de 2012 17 / 35
Preliminary Results
Spatial and temporal evolution in a drought season
[email protected] (INIA) Drought index based en RS using R 7 de diciembre de 2012 18 / 35
Preliminary Results
Spatial and temporal evolution in a drought season
[email protected] (INIA) Drought index based en RS using R 7 de diciembre de 2012 19 / 35
Preliminary Results
Spatial and temporal evolution in a drought season
[email protected] (INIA) Drought index based en RS using R 7 de diciembre de 2012 20 / 35
Preliminary Results
Spatial and temporal evolution in a drought season
[email protected] (INIA) Drought index based en RS using R 7 de diciembre de 2012 21 / 35
Preliminary Results
Spatial and temporal evolution in a drought season
[email protected] (INIA) Drought index based en RS using R 7 de diciembre de 2012 22 / 35
Preliminary Results
Spatial and temporal evolution in a drought season
[email protected] (INIA) Drought index based en RS using R 7 de diciembre de 2012 23 / 35
Preliminary Results
Spatial and temporal evolution in a drought season
[email protected] (INIA) Drought index based en RS using R 7 de diciembre de 2012 24 / 35
Preliminary Results
Spatial and temporal evolution in a drought season
[email protected] (INIA) Drought index based en RS using R 7 de diciembre de 2012 25 / 35
Preliminary Results
Spatial and temporal evolution in a drought season
[email protected] (INIA) Drought index based en RS using R 7 de diciembre de 2012 26 / 35
Preliminary Results
Spatial and temporal evolution in a drought season
[email protected] (INIA) Drought index based en RS using R 7 de diciembre de 2012 27 / 35
Preliminary Results
Spatial and temporal evolution in a drought season
[email protected] (INIA) Drought index based en RS using R 7 de diciembre de 2012 28 / 35
Preliminary Results
Spatial and temporal evolution in a drought season
[email protected] (INIA) Drought index based en RS using R 7 de diciembre de 2012 29 / 35
Preliminary Results
Spatial and temporal evolution in a drought season
[email protected] (INIA) Drought index based en RS using R 7 de diciembre de 2012 30 / 35
Preliminary Results
Spatial and temporal evolution in a drought season
[email protected] (INIA) Drought index based en RS using R 7 de diciembre de 2012 31 / 35
Preliminary Results
Spatial and temporal evolution in a drought season
[email protected] (INIA) Drought index based en RS using R 7 de diciembre de 2012 32 / 35
Recommendations
Recommendations
• Analysis in the agricultural area (LANDCOVER).
• Consider the period most sensitive for crop growth.
• Validation of the VCI, make regression analysis with some variables.(crop yield, biomass, rainfall,...)
• Make research in the sense to extend the time series of NDVI images(NOAA, AVHHR).
• Sophisticated time series analysis.
• Extend the analysis to whole country.
[email protected] (INIA) Drought index based en RS using R 7 de diciembre de 2012 34 / 35
Recommendations
Thanks?Questions?
[email protected] (INIA) Drought index based en RS using R 7 de diciembre de 2012 35 / 35