MODELING WHEAT YIELD BY USING PHENOLOGYCAL METRICS DERIVED FROM SENTINEL2 IN ARID AND SEMI-ARID REGIONS- A case study in MOROCCO-

ABSTRACT  Context and background Wheat is one of the oldest cultivated plants in the world and has always been one of the most important staples for millions of people around the world and especially in North Africa, where wheat is the most used crop for typical food industry. Thus, an operational crop production system is needed to help decision makers make early estimates of potential food availability Yield estimation using remote sensing data has been widely studied, but such information is generally scarce in arid and semi-arid regions such as North Africa, where interannual variations in climatic factors, and spatial variability in particular, are major risks to food security.Goal and Objectives: The aim of this study is to develop a model to estimate wheat yield based on phenological metrics derived from SENTINEL-2 NDVI images in order to generalize a spatial model to estimate wheat yields in Morocco's semi-arid conditionsMethodology:The 10 m NDVI time series was integrated into TIMESAT software to extract wheat phenology-related metrics during the 2018-2019 agricultural season, the period in which ground truth data was collected.  Through the multiple stepwise regression method, all phenological metrics were used to predict wheat yield. Moreover, the accuracy and stability of produced models were evaluated using a K-fold cross-validation (K-fold CV) method.Results:The results of the obtained models indicated a good linear correlation between predicted yield and field observations (R2 = 0.75 and RMSE of 7.08q/ha). The obtained method could be a good tool for decision makers to orient their actions under different climatic conditions

Typologie du zircon des granitoïdes de Bouskour et d'Ougnat (Saghro, Anti-Atlas, Maroc) : Comparaison et signification géodynamique Zircon typology of Bouskour and Ougnat granitoids (Saghro, Anti-Atlas, Morocco) : comparison and geodynamic implication

International audienceLes granitoïdes de Bouskour et de l'Ougnat (Saghro, Anti-Atlas) représentent respectivement les intrusions les plus proches et les plus éloignées par rapport à l'accident majeur de l'Anti-Atlas. Ils sont composés à Bouskour de diorite quartzique, de granodiorite à amphibole et de granite à biotite et à Ougnat de diorite quartzique, de granodiorite à amphibole/biotite et de granite à grenat. La typologie du zircon appliquée à ces granitoïdes montre l'existence de trois tendances magmatiques dans les deux boutonnières. Une tendance granodioritique ou moyennement potassique représentée par les diorites quartziques et les granodiorites dans ces deux ensembles et une tendance calco-alcaline plus potassique représentée par le granite à biotite à Bouskour. Ces deux suites possèdent une origine hybride croûte-manteau. Le granite à grenat de l'Ougnat représente la troisième tendance avec une origine plutôt crustale. Cette répartition montre que le composant crustal augmente depuis Bouskour jusqu'à l'Ougnat impliquant un épaississement crustal au niveau de Saghro au cours du Néoprotérozoïque. Both the Bouskour and the Ougnat granitoids belong to Sahgro intrusions, which are near and far from the major Anti-Atlas accident respectively. These complexes are composed of quartz diorite, amphibole granodiorite and garnet granite in Bouskour, and quartz diorite, amphibole/biotite granodiorite and garnet granite in Ougnat hills. Zircon typology in these granitoids shows three magmatic trends. First, a medium-K calc-alkaline granodiorite trend formed by quartz diorites and amphibole granodiorites in both complexes. Second, the biotite granites of Bouskour record a high-K calc-alkaline trend. Both trends have a hybrid mantle-crust origin. Garnet granite represents the third trend with a crustal origin. These signatures recorded by the Saghro granitoids suggest crustal thickening during the Neoproterozoic

REVIEW OF WHEAT YIELD ESTIMATING METHODS IN MOROCCOvvvvvvv

Wheat is one of the oldest crops in the world and has always been one of the most important staple foods for millions of people around the world, especially in North Africa, where wheat is the most dominant crop. The importance of wheat yield estimation is well known in agricultural management and policy making at regional and national levels. In semi-arid areas such as the case of Morocco, an operational cereal yield estimating system that could assist decision makers in planning annual imports is needed. In some developed countries, several effective tools are now available to monitor crops and optimize farm-level decisions by combining crop simulation models with seasonal forecasts. However, few tools are used to effectively manage crops at the farm level to cope with climate variability and risk. The following article presents an overview of current methods used for wheat yield estimation in the world and in Morocco. Various sections describing traditional methods, simulation models, and remote sensing. Then a section is devoted to the estimation methods used in Morocco and their efficiencies. This article is very useful for researchers working on this subject because it brings together all the methods of estimating wheat yields worldwide and classifies them into categories and then situates Morocco, which is a relevant example of a North African country that is a leader in the use of spatial techniques and in the monitoring of crops, and wheat in particular

Inventory and Assessment of Geosites and Geodiversity Sites of the Ait Attab Syncline (M’goun Unesco Geopark, Morocco) to Stimulate Geoconservation, Geotourism and Sustainable Development

The Ait Attab syncline, in the southwestern part of the Moroccan Central High Atlas (CHA), is a vast basin characterised by an exceptional geodiversity illustrating the complete sedimentary series in the CHA. This series offers the opportunity to study regional palaeogeography, transgressive and regressive megasequences, Jurassic-Cretaceous volcanism and Atlas tectonics, and various fossils, including dinosaur footprints. The study area also harbours considerable landscape and cultural wealth that can play a significant role in sustainable geotourism and geoeducation development. To promote and protect this geoheritage wealth, the present work provides the first quantitative and qualitative inventory of geosites of interest by adopting Brilha’s (2016) method. Thus, 3 geotrails covering 8 geosites and 11 geodiversity sites have been selected. The evaluation of these sites confirms their scientific and educational importance, which helps understand the geological, tectonic and palaeogeographical evolution of the Ait Attab syncline. The tourist value of these sites is also high, explained by the high interpretative potential of the geosites and their location as a gateway to the M’Goun Unesco geopark. The degradation risk assessment showed that most of these sites have a medium risk, except for palaeontological and magmatic sites, which have a high degradation risk

Monitoring of forest cover dynamics in eastern area of Béni-Mellal Province using ASTER and Sentinel-2A multispectral data

This study aimed to monitor and analyze the spatial and temporal dynamic of forest cover in Eastern area of Beni-Mellal Province (Morocco), using multispectral ASTER and Sentinel-2A MIS images acquired in 2001 and 2015, respectively. The supervised classification algorithm and NDVI were combined within a GIS environment to quantify the extent and density change of forest cover stands, i.e., Holm oak, Aleppo pine, Thya, Zea oak, Crops & others and Bare ground. The classification overall accuracy was 97.76 and 95.80% in 2001 and 2015 images, respectively. The result revealed an overall forest cover change with an increase in forested area. All species stands showed expansion at the expense of the bare ground and crops & others classes. The density maps showed a net density change with an expansion of dense forest class. The observed forest cover expansion may be due to the favourable climate in the examined period, the protection, the reforestation programs and the regeneration through clandestine cutting. These results constituted the first attempt at mapping and monitoring of forest cover change in the study region that used a remote sensing-based product. They will help authorities and forest managers for the development of sustainable forest conservation and management decisions

Monitoring of forest cover dynamics in eastern area of Béni-Mellal Province using ASTER and Sentinel-2A multispectral data

<p>This study aimed to monitor and analyze the spatial and temporal dynamic of forest cover in Eastern area of Beni-Mellal Province (Morocco), using multispectral ASTER and Sentinel-2A MIS images acquired in 2001 and 2015, respectively. The supervised classification algorithm and NDVI were combined within a GIS environment to quantify the extent and density change of forest cover stands, i.e., Holm oak, Aleppo pine, Thya, Zea oak, Crops & others and Bare ground. The classification overall accuracy was 97.76 and 95.80% in 2001 and 2015 images, respectively. The result revealed an overall forest cover change with an increase in forested area. All species stands showed expansion at the expense of the bare ground and crops & others classes. The density maps showed a net density change with an expansion of dense forest class. The observed forest cover expansion may be due to the favourable climate in the examined period, the protection, the reforestation programs and the regeneration through clandestine cutting. These results constituted the first attempt at mapping and monitoring of forest cover change in the study region that used a remote sensing-based product. They will help authorities and forest managers for the development of sustainable forest conservation and management decisions.</p