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The destruction of the Aravali hills has led to significant loss of vegetation and soil cover.
The degradation has disrupted local biodiversity, according to a study in Earth Science Informatics.
The study used the Enhanced Vegetation Index (EVI) to assess biomass condition, finding the lowest values (0 to -0.2) in the upper central Aravalli region of Nagaur district.
The regions in the upper and lower Aravali range recorded high positive rates of carbon flux as they received high rainfall and had protected areas
Aravalli range
The Aravalli Range is a mountain range in Northern-Western India
Rajasthan occupies 80% of the world’s oldest hill range, while other States — Haryana, Delhi, and Gujarat — have 20% share in the terrain.
With a length of 692 km and a width variation of 10 km to 120 km, Aravali forms an ecotone zone between Thar desert and the Gangetic plain, in a semi-arid environment.
The range comprises over 500 hillocks, and the altitude of its highest peak, Guru Shikhar in Mount Abu, is 1,722 metres
The Aravalli Range, an eroded stub of ancient mountains, is believed to be the oldest range of fold mountains in India. (Residual fold mountain)
The natural history of the Aravalli Range dates back to times when the Indian Plate was separated from the Eurasian Plate by an ocean
It is part of the Indian Shield that formed from a series of cratonic collisions
Enhanced Vegetation Index (EVI)
The EVI is a spatial tool in remote sensing that can be used to estimate the biomass and carbon sequestration potential of forests.
It is also used to monitor the health of forests over large areas by detecting changes in vegetation.
It is regarded as the modified version of Normalized Difference Vegetation Index (NDVI) with a high potentiality of vegetation monitoring by correcting all the external noises.
Vegetation Indices are calculated from the bilateral surface reflectance that has been concealed for cloud, smoke, aerosols, water, cloud shadows, etc.
The value of EVI generally ranges from -1 to 1.
A value closer to 1 represents healthy vegetation and a value closer to 0 represents unhealthy vegetation.
EVI uses the blue, red, and NIR band
It incorporates an “L” value to adjust for canopy background, “C” values as coefficients for atmospheric resistance, and values from the blue band (B).
These enhancements allow for index calculation as a ratio between the red (R) and near infrared (NIR) values, while reducing the background noise, atmospheric noise, and saturation in most cases.
Carbon flux
The direction and rate of transfer, or flow, of carbon between Earth’s carbon pools, such as the oceans, atmosphere, land, and other living things.
Carbon fluxes can be :
natural exchanges, such as land-atmosphere and ocean-atmosphere fluxes,
anthropogenic exchanges, such as urban carbon fluxes.
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