GLC 2000 land cover map of the desert

GLC 2000 land cover map of the desert locust recession area First results E. Bartholomé, JRC Ispra M. Cherlet, FAO Rome 6/7/2021 GLC 2000 – “FIRST RESULTS” WORKSHOP JRC – Ispra, 18 -22 March 2002

The desert locust recession area 19°W – 80° 30’E, 46°N – 4°N Main focus on drylands 6/7/2021 GLC 2000 – “FIRST RESULTS” WORKSHOP JRC – Ispra, 18 -22 March 2002

Input data • S 10 NDVI for 2000 • Re-scaled in vegetation cover percentage • Soil effect removed (per-pixel method) • Temporal profile smoothed (see ad hoc presentation) 6/7/2021 GLC 2000 – “FIRST RESULTS” WORKSHOP JRC – Ispra, 18 -22 March 2002

Classification procedure Based on temporal profiles Rigid tresholds on: • Max vegetation cover in 2000 • Season duration cover • Seasonality: max in summer or winter, or double seasonality 1/3 time 6/7/2021 GLC 2000 – “FIRST RESULTS” WORKSHOP JRC – Ispra, 18 -22 March 2002

Rationale • Cover max – corresponds to max development of vegetation – Best correlates with above-ground biomass • duration Duration close to phenological definition, but time lag 6/7/2021 GLC 2000 – “FIRST RESULTS” WORKSHOP JRC – Ispra, 18 -22 March 2002

Classes Max cover 1 BARE AREAS 2 SPARSE HERBACEOUS VEGETATION - NOT ANNUAL TBC 100% 3 SPARSE HERBACEOUS VEG 9 4 CLOSED-OPEN HERBACEOUS VEG 5 SPARSE DECIDUOUS SHRUB AND SPARSE HERBACEOUS VEGETATION 75% 6 OPEN DECIDUOUS SHRUB AND OPEN HERBACEOUS VEGETATION 6 50% 8 7 SPARSE DECIDUOUS SHRUB AND SPARSE HERBACEOUS VEGETATION AND SPARSE TREE LAYER 4 10 6 8 5 7 8 OPEN DECIDUOUS SHRUB AND OPEN HERBACEOUS VEGETATION AND SPARSE TREE LAYER 9 CLOSED-OPEN DECIDUOUS SHRUB AND CLOSED- OPEN HERBACEOUS VEGETATION AND OPEN TREE LAYER 10 NOT DEFINED 25% 10% 5% 1 6/7/2021 2 3 3 6 9 12 months 1 The same applies for winter vegetation Growth and double season growth GLC 2000 – “FIRST RESULTS” WORKSHOP JRC – Ispra, 18 -22 March 2002 duration

Result 6/7/2021 GLC 2000 – “FIRST RESULTS” WORKSHOP JRC – Ispra, 18 -22 March 2002

Close-up (1) Sarir (Libya) Irrigated agriculture 6/7/2021 GLC 2000 – “FIRST RESULTS” WORKSHOP JRC – Ispra, 18 -22 March 2002

Close-up (2) Luxor (Egypt) double growing season 6/7/2021 GLC 2000 – “FIRST RESULTS” WORKSHOP JRC – Ispra, 18 -22 March 2002

Close-up (3) Senegal - Mauritania 6/7/2021 GLC 2000 – “FIRST RESULTS” WORKSHOP JRC – Ispra, 18 -22 March 2002

Observation 1 • Noise in the 3 -5% cover range Haruj es Sawda Volcano (Libya) 6/7/2021 GLC 2000 – “FIRST RESULTS” WORKSHOP JRC – Ispra, 18 -22 March 2002

Observation 2 • Specific year 2000 situation 1999 -2000 Land cover map 6/7/2021 2000 -2001 GLC 2000 – “FIRST RESULTS” WORKSHOP JRC – Ispra, 18 -22 March 2002

Observation 3 • Cropland not detected per se: low % of surface 6/7/2021 GLC 2000 – “FIRST RESULTS” WORKSHOP JRC – Ispra, 18 -22 March 2002

conclusions • The method seems efficient for dryland vegetation (bare soil correctly mapped!) • The method is sensitive to the specific year for very sparse vegetation • Some “soil contamination” • Need for regional analysis to label the land cover classes 6/7/2021 GLC 2000 – “FIRST RESULTS” WORKSHOP JRC – Ispra, 18 -22 March 2002