RESULTS

Evapotraspiration maps – Nile Delta (DLR – CU/CLAC)

Evapotranspiration (ET) values were obtained from 46 images for the region of Nile Delta (Egypt) and 42 for Kairouan Region in Tunisia in the period November 2017 – October 2018 (MODIS – MOD16A2 ET / Latent Flux 500 m pixel resolution product).

In order to obtain ET variability between seasons, data sets were segregated between dry and humid periods. Dry season within the Delta -Nile comprises the months between May – October 2018 (23 images) whereas humid season is between November 2017 and April 2018 (23 images). Dry periods in Kairouan on the other hand occurs between the months April and August (2018) while humid periods comprehend the months between November (2017) and February (2018) with 22 and 16 images respectively.

Mean values for annual, dry and humid seasons were estimated based on the calculation of percentiles 50th in order to visually identify areas with highest and lowest ET values.

Humid season mean MODIS16A2 evapotranspiration values of the Nile Delta Egypt for the reference year 2018

Dry season mean MODIS16A2 evapotranspiration values of the Nile Delta Egypt for the reference year 2018

Annual mean MODIS16A2 evapotranspiration values of the Nile Delta Egypt for the reference year 2018

Rainy season mean MODIS16A2 evapotranspiration values of the Kairouan Region Tunisia for the reference year 2018

Dry season mean MODIS16A2 evapotranspiration values of the Kairouan Region Tunisia for the reference year 2018

Annual mean MODIS16A2 evapotranspiration values of the Kairouan Region Tunisia for the reference year 2018

Estimation of EVI anomalies (drought indices) for Egypt (Nile Delta) and Tunisia (Medenine and Kairouan)

In order to investigate vegetation stress from crop fields over the past two decades in Egypt (Nile Delta) and Tunisia (Medenine and Kairouan), a robust and straightforward approach was applied to detect temporal and spatial patterns of vegetation condition derived from remote sensing data. Moderate Resolution Spectroradiometer (MODIS) Enhanced Vegetation Index (EVI) (MOD13Q1 Version 6, 250 m spatial resolution, 16- days composite) was applied to investigate vegetation periods between 2001 -2018.

Results from the model shown drought remarkable variability and patterns between study regions. Major negative anomalies trends (Figure 2) in Nile Delta were visible for the years 2001, 2002, 2003 and 2010. Medenine (Figure 4) on the other hand presented similar anomalies for the years 2001, 2002 and 2010 with a returning event on the year 2013.

Similar to Nile Delta and Medenine, the Kairouan region (Figure 6) shown a comparable tendency for the first 2 years and a recurring negative anomaly event over the years 2008 and 2013.

EVI anomaly map Kairouan

EVI anomaly map Medenine

EVI anomaly map Delta Nile

EVI anomaly time series Kairouan

EVI anomaly time series Medenine

EVI anomaly time series Delta Nile