TEST SITES
THE NILE DELTA
The Nile Delta is located in the central part of the Egyptian Mediterranean coastline of approximately 1000 km. It is one of the oldest densely cultivated areas in the world. The Nile Delta supports more than 60% of Egypt’s agricultural land. Approximately 85% of Egyptian water resources (mainly supplied by the Nile) are committed to irrigation of the 3.4 million hectares of cultivated lands, and about 65% of these agricultural activities are within the delta area. The delta cultivates mixed crops (wheat, corn, rice, and other crops), vegetables, citrus fruits, some cotton, and groundnuts.
The Nile delta lands could be considered as problematic lands regarding their fine texture, poor drainage, as well as the saltwater intrusion into the groundwater table. Therefore, these soils are threatened by land degradation processes, as drought, soil compaction, and salinization, more than any other alluvial soils. Moreover, the delta region hosts about 41% of the country’s population although it represents about 2% of the total country’s area; therefore the urban encroachment and land degradation are also adding additional driving forces of land cover changes as clearly observed in different regions under arid and semi-arid climatic conditions.
OPTIMED working for optimum planning and adaptation strategies in the Egyptian Delta to optimize water usage in agricultural activities and reduce the expected risk exposure.
MEDENINE AREA
For this study, three olive orchards were selected as the experimental study area in Medenine Governorate to explore the use of Remote Sensing data (high resolution) for the assessment of drought affected olive groves
Zammour test area
The orchard is a family olive grove located in Zammour, which is a typical mountainous olive growing area of southern Tunisia, situated at about 35 km West of Medenine (33° 16′ 04,91”N, 10 ° 11′ 16,53” E). This orchard covers 0.6 ha. The climate is of Mediterranean arid type with hot and dry summers and mild winter, having an annual rainfall of 194 mm. Located in a mountainous region, the inter-annual variability shows more or less long series of wet years or dry years. Successive dry years of less than 100 mm / year are rare in the region. The average annual temperature is 18.7◦C, the coldest month is December (mean minimum daily temperature 14◦C) and the warmest month is July (mean maximum daily temperature 25◦C). The olive trees were planted at 36 trees/ha (16m*16m), cultivars Chemlali and Zalmati, in a downhill under soil and water conservation structures and were grown under rainfed conditions.
Dar Dhaoui test area In the plain area , the experiment was carried out from April 2019 in an olive orchard of Dar Dhaoui, which is located 31 km East of Medenine (33° 17′ 32,62” N, 10° 47′ 03,43”E). This orchard covers 15 ha. The region is characterized by a Mediterranean arid climate with yearly averages of 150 mm rainfall, 1170 mm ET0 and high temperatures in the summer (higher than 35 °C). This orchard contained 60 year-old olive trees (Olea europaea L.), cultivars Zalmati and Chemlali. The tree 24 * 24 m apart were grown under rainfed condition.
Zarzis test area The olive orchard of Zarzis is situated in the coastal plain of Medenine, southeastern Tunisia (33° 34’ 49’’ N, 11° 02’ 12’’ E). This orchard covers 1,12 ha. The climate is of upper arid type with temperate winter, having an annual rainfall of 245 mm. The average annual temperature is 20◦C, the coldest month is December (mean minimum daily temperature 8◦C) and the warmest month is July (mean maximum daily temperature 37◦C). This orchard contained 22 olive trees planted with a spacing 24 * 24 m, cultivars Chemlali and Zalmati, were grown under rainfed condition.
MERGUELLIL PLAIN (TUNISIA)
The Merguellil plain is located on the Kairouan plain (35 ° 30 ′ – 35 ° 50 ′ N; 9 ° 10 ′ – 10 ° 10 ′ E), in Central Tunisia. It is a part of Merguellil downstream catchment composed by the large and flat Kairouan alluvial plain that extends over about 3000 km2. It covered an area of 300 km2 close to the Haouareb dam. The plain is located in the semi-arid region of Tunisia where precipitation is highly variable in time and space with frequently occurring drought events. The rainy season lasting from October to May, with the two rainiest months being October and March. Average annual rainfall is around 300 mm, average annual temperature is 19.2 °C and average potential evapotranspiration is close to 1600 mm. because surface water ressources are limited and unreliable spatial and temporal availability, groundwater is pumped for irrigation and to supply drinking water to the Kairouan region. The landscape is mainly flat and dominated large irrigated fields caracterized by traditional crops (Piments, tomatoes, market gardens associated with fruits trees and olive trees), in the south part. Rainfed cereals and olive trees dominated the south part. In Merguellil plain, olive tree, the symbolic figure of the landscapes of the Mediterranean, is cultivated in rainfed (traditional) with an inter-row of 10 to 20 m ; and irrigated with an inter-row 4 to 7m (intensive), in solo or with intercropped (cereals, market gardening and arboriculture).