Using Climatic data in Diva GIS

Franck Theeten,Royal Museum for central AfricaCabin training 2013

Source data

• 1. Go on the ‘downloads’ part of the DIVA GIS website (http://www.diva-gis.org )

• 2. Select « Free Spatial data -> Global Climat data»• 3. 3 versions of the Worldclim datasets (Museum of

vertebrate zoology, University of Berkeley) are actually available they do no cover the oceans– 3.1: a direct link to the Worldclim website (

http://www.worldclim.org)– 3.2: The current climat data (1950-2000) produced in 2004– 3.3: a predictive model produced in 2003 by B. Govindsamy, P. B.

Duffy, J. Coquard), corresponding to the CCM 3 model of the American National Center for Athmospheric Research (NCAR)

Source data

• For this exercise, download and unzip

– 3.2: The current climat data (1950-2000) produced in 2004

Data preparation

• The climatic model must be used in combination with distribution data

• Open a background layer with the world boundaries

Importation of delimited text distribution data

• Open the ‘calipidae_exo_divagis_wgs84.csv’ file and import it into DivaGIS 1->Data2->Import point to Shapefile3->’From textfile (TXT)’4-> register the source file in ‘Input File’5-> Choose the appropriate delimiter (here ‘tab’)6-> Check that the X (latitude) and Y (longitude) columns correspond to the column and contain values fitting the same reference system as the project (here: decimal degrees)7-> a new shapefile will be created at the location defined in ‘Output File’ (by default, Diva GIS set it to the same folder as the original input file)

Importation of delimited text distribution data

Importation of delimited text distribution data

Selection of the relevant points

• 1: The calapiddae shapefiles contain coordinates in the wrong format that appear outside of the world boundaries and disturb the processing of data (this is actually a data quality issue)

• 2: We will exclude these data by creating a shapfile taking only the points within between longitude -180 and 180 and latitude -90 and latitude 90

Selection of the relevant points

• Ensure that the layer with the distribution data is the active one• Go on « Layer -> Select Features»

• Select the world boundaries by dragging the mouse on the screen to draw a bounding box (the points should be highlighted in yellow)

Selection of the relevant points

• Go on « Data-> Selection to new shapefile » to create a shapefile containing only the slected points (the shapefile should appear in the project)

Importation of the climatic database

• 1: Go to the « tools » tab• 2: click on « Options »• 3: Select «the Climate » tab in the form that

appears

Importation of the Climatic database

• In the Folder windows, give the location of the root of the directory containing the clumat files

• Define an explicit name in the windows situated left of the « Make default » button

• Click « Make Default »• Click « Apply »

Importation of the climatic database

Get climatic information bound to a specific location

• Enable the button• Clic on a location in the map

Get climatic information bound to a specific location

• Enable the button• Clic on a location in the map

Get climatic information bound to a specific location

• NB: the resolution of the grid linked to these statistics is available in « Tools->Options->Cell size»

Applying a color scheme to the climatic data

• 1) Click on « Data -> Climate->Map»

Applying a color scheme to the climatic data

• 2) Select the criteria you want to map in the « Output » drop down menu– 5 available

• minimum temperature• mean temperature• maximum temperature• Altitude• precipitation• ‘bioclim’ (combination of 19 variables)

• 3) Give the location of the output shapefile in « File »

Applying a color scheme to the climatic data

Viewing climatic data

• Select the distribution layer as active (calappidae_exo_divagis_wgs84only)

• Go on ‘Modeling’• Go on ‘BioClim/Domain’

Viewing climatic data • Several windows are available, linked to the 19 BioCLIM variables

– BIO1 = Annual Mean Temperature– BIO2 = Mean Diurnal Range (Mean of monthly (max temp - min temp))– BIO3 = Isothermality (BIO2/BIO7) (* 100)– BIO4 = Temperature Seasonality (standard deviation *100)– BIO5 = Max Temperature of Warmest Month– BIO6 = Min Temperature of Coldest Month– BIO7 = Temperature Annual Range (BIO5-BIO6)– BIO8 = Mean Temperature of Wettest Quarter– BIO9 = Mean Temperature of Driest Quarter– BIO10 = Mean Temperature of Warmest Quarter– BIO11 = Mean Temperature of Coldest Quarter– BIO12 = Annual Precipitation– BIO13 = Precipitation of Wettest Month– BIO14 = Precipitation of Driest Month– BIO15 = Precipitation Seasonality (Coefficient of Variation)– BIO16 = Precipitation of Wettest Quarter– BIO17 = Precipitation of Driest Quarter– BIO18 = Precipitation of Warmest Quarter– BIO19 = Precipitation of Coldest Quarter

Viewing climatic data

• Visualisation windows– Frequency (synchronized with the map)– Outliers data (global view on the 19 variables +

highligthing of outliers)– Histograms– Enveloppe (combination of 2 variables, contained

within a certain percentile, tje points within the envoeloppe are highlighted in yellow)

– Predict

Frequency

• The map is interactive (clicking on a point highlight on the map)

Outliers

• The horizontal axe corresponds to the 19 BioCLIM variables

Envelope

• This calculation use 2 variables and a percentile (applied on the 2 variables and then combined) to define an envelope. Points within the envelope appear yellow on the map (remember that marine observation do not fit BioCASe)