Data Elements

Species’ probability of occurrence

What is probability of occurrence?

Probability of occurrence is the chance of finding the potential habitat area of a particular species inside a pixel based on given occurrence points and climatic parameters. The resolution of the final probability distribution map is 1km* 1km. Hence probability of occurrence in our case is the chance of finding potential habitat area of a species inside the area of 1km * 1km. The value for probability of occurrence ranges from 0-1000 where 0 means no probability of finding the species whereas 1000 means 100% chance of finding the particular species. This range can be normalized by dividing the standard values by 10 to get a percentage scale ranging from 0-100.

How many levels will the probability of occurance have?

The Probability of occurrence will be divided into 3 classes/levels namely:

  • High:Probability of occurrence>=75%
  • Moderate:Probability of occurrence>=50% and <75%
  • Low:Probability of occurrence>50%

Holdridge Life Zones

What are life zones? HLZ is a climate based vegetation classification scheme used to segregate a particular area into various life zones.Biotemperature,precipitation,potential evapotranspiration and elevation are the four major parameters used in HLZ classification. The resolution of the HLZ map depends on the resolution of the input climatic variables. If climatic data from Worldclim is used , the resolution will be identical to the resolution of the potential habitat area map i.e, 1km*1km.

How many different types of zones are there?

This can range between anywhere 15-25. However, the major zones are:

  • Alpine
  • Subalpine
  • Cool Temperate
  • Warm Temperate
  • Subtropical
  • Tropical

The additional zones are generated by further subdividing the above mentioned zones based on elevation and latitude.Currently 21 life zones were identified on the map generated by using the climatic data from Worldclim.

Climate change scenarios

According to the 5th assessment report of IPCC,four Representative Concentration Pathways(RCP) are identified. The RCPs predicts how the emission will evolve in time which consequently will give rise to different climatic conditions in the future.Various environmental and socio economic models are used to derive the RCPs. We are using the RCP 4.5 and 8.5 climatic scenarios.The RCP 4.5 more or less tries to mimic the business as usual trend of development with CO2 emissions peaking around the mid of the 21st century and slowly stabilizing towards the end of the century. The RCP 8.5 scenario is the worst case scenario which assumes the CO2 emissions will go in an overshoot mode giving rise to extreme climate change.