Linkages between rainfed cereal production and agricultural drought through remote sensing indices and a land data assimilation system : A case study in Morocco

Abstract

In Morocco, cereal production shows high interannual variability due to uncertain rainfall and recurrent drought periods. Considering the socioeconomic importance of cereal for the country, there is a serious need to characterize the impact of drought on cereal yields. In this study, drought is assessed through (1) indices derived from remote sensing data (the vegetation condition index (VCI), temperature condition index (TCI), vegetation health ind ex (VHI), soil moisture condition index (SMCI) and soil water index for different soil layers (SWI)) and (2) key land surface variables (Land Area Index (LAI), soil moisture (SM) at different depths, soil evaporation and plant transpiration) from a Land Data Assimilation System (LDAS) over 2000–2017. A lagged correlation analysis was conducted to assess the relationships between the drought indices and cereal yield at monthly time scales. The VCI and LAI around the heading stage (March-April) are highly linked to yield for all provinces (R = 0.94 for the Khemisset province), while a high link for TCI occurs during the development stage in January-February (R = 0.83 for the Beni Mellal province). Interestingly, indices related to soil moisture in the superficial soil layer are correlated with yield earlier in the season around the emergence stage (December). The results demonstrate the clear added value of using an LDAS compared with using a remote sensing product alone, particularly concerning the soil moisture in the root-zone, considered a key variable for yield production, that is not directly observable from space. The time scale of integration is also discussed. By integrating the indices on the main phenological stages of wheat using a dynamic threshold approach instead of the monthly time scale, the correlation between indices and yield increased by up to 14%. In addition, the contributions of VCI and TCI to VHI were optimized by using yield anomalies as proxies for drought. This study opens perspectives for the development of drought early warning systems in Morocco and over North Africa, as well as for seasonal crop yield forecasting.

• author: Bouras, El Houssaine ; Jarlan, Lionel ; Er-Raki, Salah ; Albergel, Clément ; Richard, Bastien ; Balaghi, Riad and Khabba, Saïd
• publishing date: 2020-12-02
• type: Contribution to journal
• publication status: published
• subject: Other Agricultural Sciences
• keywords: Agricultural drought, Cereal yield, Land data assimilation systems, Remote sensing, Semiarid region
• in: Remote Sensing
• volume: 12
• issue: 24
• article number: 4018
• pages: 35 pages
• publisher: MDPI AG
• external identifiers: scopus:85097575571
• ISSN: 2072-4292
• DOI: 10.3390/rs12244018
• language: English
• LU publication?: no
• additional info: Funding Information: Funding: This work was carried out within the framework of the Joint International Laboratory TREMA (http://lmi-trema.ma) (IRD, UCAM, DMN, CNESTEN, ABHT, and ORMVAH) and the ERANETMED03–62 CHAAMS ‘global CHange: Assessment and Adaptation to Mediterranean region water Scarcity’ project. The European Commission Horizon 2020 Programme for Research and Innovation (H2020) in the context of the Marie Sklodowska-Curie Research and Innovation Staff Exchange (RISE) action (REC project, grant agreement no. 645642), followed by the ACCWA project, grant agreement no. 823965) and by SAGESSE PPR/2015/48 ‘Système d’Aide à la décision pour la GEstion des reSSources en Eau’ are acknowledged for the mobility grants of E. Bouras. The H2020 PRIMA ALTOS project, MISTRALS/SICMED2 and PHC Toubkal #39064WG/2018 are also acknowledged for additional funding. E. Bouras was supported by a fellowship from the ARTS program from IRD, France. Funding Information: This work was carried out within the framework of the Joint International Laboratory TREMA (http://lmi-trema.ma) (IRD, UCAM, DMN, CNESTEN, ABHT, and ORMVAH) and the ERANETMED03?62 CHAAMS ?global CHange: Assessment and Adaptation to Mediterranean region water Scarcity? project. The European Commission Horizon 2020 Programme for Research and Innovation (H2020) in the context of the Marie Sklodowska-Curie Research and Innovation Staff Exchange (RISE) action (REC project, grant agreement no. 645642), followed by the ACCWA project, grant agreement no. 823965) and by SAGESSE PPR/2015/48 ?Syst?me d?Aide ? la d?cision pour la GEstion des reSSources en Eau? are acknowledged for the mobility grants of E. Bouras. The H2020 PRIMA ALTOS project, MISTRALS/SICMED2 and PHC Toubkal #39064WG/2018 are also acknowledged for additional funding. E. Bouras was supported by a fellowship from the ARTS program from IRD, France. Publisher Copyright: © 2020 by the authors. Licensee MDPI, Basel, Switzerland.
• id: 427c4074-830c-4c94-a383-1550553603b6
• date added to LUP: 2023-01-04 09:50:13
• date last changed: 2023-01-31 13:18:47