sistem de control si monitorizare_en
TRANSCRIPT
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Unwanted vegetation and abandoned lands detection and mapping
Motivations
Council Regulation (EC) No 73/2009 Article 6 Good agricultural and environmental condition
Minimum level of maintenance:
Ensure a minimum level of maintenance and avoid the deterioration of habitatsRetention of landscape features, including, where appropriate, hedges, ponds, ditches trees inline,
in group or isolated and field margins
Avoiding the encroachment of unwanted vegetation on agricultural land
Protection of permanent pasture
Objective
Develop a methodology for identification of unwanted vegetation, abandoned lands from satelliteimages to be used in visual photointerpretation CAPI
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Zona de studiu si datele folosite
The chosen study area is a part of Mehedinti county
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Procedures
From satellite images vegetation indices NDVI , MSAVI , MMSAVI was generated .
NDVI was generated for all HR images
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NDVI was selected because is probably the most commonly used index in the
last decades when studying vegetation.
Its deficiencies and advantages have been thoroughly studied and are actually well known. This provided to the project results a kind of point of reference fromwhere the performance of the other techniques was evaluated. NDVI is defined as:
.
where R and NIR represent the surface reflectance on the red and near
infrared regions of the spectrum, respectively.
MSAVI
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The modified soil-adjusted vegetation index (MSAVI) and its later revision, MSAVI2, are soil
adjusted vegetation indices that seek to address some of the limitation of NDVI when applied to areaswith a high degree of exposed soil surface.
where RED is the red band reflectance from a sensor, NIR is the near infrared band reflectance, and L is
the soil brightness correction factor. MSAVI uses the following formula to calculate L, where s is theslope of the soil line from a plot of red versus near infrared brightness values. :
Modified MSAVI
The formula of calculation is the same as in MSAVI , the only exception is instead of deducting
RED band from NIR , we deducted GREEN band from NIR
After the stage where all 3 indices (NVDI,MSAVI, MMSAVI) Fig. 1 a stack was created ,
NDVI,MSAVI,MMSAVI become a layer of the new image obtained like this Fig. 2 , Fig. 3 .
The stacks was classified using unsupervised classification ,obtained classe was gruped in 4
principal classes Fig. 5:
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NDVI 9 May NDVI 14 Jun NDVI 14 Jul
MSAVI 9 May MSAVI 14 Jun MSAVI 14 Jul
MMSAVI 9 May MMSAVI 14 Jun MMSAVI 14 Jul
Fig. 1
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Stacks
NDVI
MSAVI
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Stacks overview
NDVI MMSAVI MMSAVI
Stacks classification
NDVI MSAVI MMSAVI
Fig 3
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Diferente
NDVI MSAVI MMSAVI
Fig. 4
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Abandoned vs uncultivated land
Fig. 5
Abandoned land
Uncultivated landUncultivated land encroachement of unwanted vegetation
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Conclusions
- Vegetation indices classification can be a great help in taking decisions regarding GAECs- The method doesnt eliminate the classical visual interpretation on time series satellite images
To do in the future:Supervised classification
Initial masking of urban elements