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26 pages, 3252 KiB  
Article
LMFE: A Novel Method for Predicting Plant LncRNA Based on Multi-Feature Fusion and Ensemble Learning
by Hongwei Zhang, Yan Shi, Yapeng Wang, Xu Yang, Kefeng Li, Sio-Kei Im and Yu Han
Genes 2025, 16(4), 424; https://doi.org/10.3390/genes16040424 - 31 Mar 2025
Viewed by 526
Abstract
Background/Objectives: Long non-coding RNAs (lncRNAs) play a crucial regulatory role in plant trait expression and disease management, making their accurate prediction a key research focus for guiding biological experiments. While extensive studies have been conducted on animals and humans, plant lncRNA research [...] Read more.
Background/Objectives: Long non-coding RNAs (lncRNAs) play a crucial regulatory role in plant trait expression and disease management, making their accurate prediction a key research focus for guiding biological experiments. While extensive studies have been conducted on animals and humans, plant lncRNA research remains relatively limited due to various challenges, such as data scarcity and genomic complexity. This study aims to bridge this gap by developing an effective computational method for predicting plant lncRNAs, specifically by classifying transcribed RNA sequences as lncRNAs or mRNAs using multi-feature analysis. Methods: We propose the lncRNA multi-feature-fusion ensemble learning (LMFE) approach, a novel method that integrates 100-dimensional features from RNA biological properties-based, sequence-based, and structure-based features, employing the XGBoost ensemble learning algorithm for prediction. To address unbalanced datasets, we implemented the synthetic minority oversampling technique (SMOTE). LMFE was validated across benchmark datasets, cross-species datasets, unbalanced datasets, and independent datasets. Results: LMFE achieved an accuracy of 99.42%, an F1score of 0.99, and an MCC of 0.98 on the benchmark dataset, with robust cross-species performance (accuracy ranging from 89.30% to 99.81%). On unbalanced datasets, LMFE attained an average accuracy of 99.41%, representing a 12.29% improvement over traditional methods without SMOTE (average ACC of 87.12%). Compared to state-of-the-art methods, such as CPC2 and PLEKv2, LMFE consistently outperformed them across multiple metrics on independent datasets (with an accuracy ranging from 97.33% to 99.21%), with redundant features having minimal impact on performance. Conclusions: LMFE provides a highly accurate and generalizable solution for plant lncRNA prediction, outperforming existing methods through multi-feature fusion and ensemble learning while demonstrating robustness to redundant features. Despite its effectiveness, variations in performance across species highlight the necessity for future improvements in managing diverse plant genomes. This method represents a valuable tool for advancing plant lncRNA research and guiding biological experiments. Full article
(This article belongs to the Section Bioinformatics)
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16 pages, 10442 KiB  
Article
Exploring Convective Drying Behavior of Hydroxide Sludges Through Micro-Drying Systems
by Azeddine Fantasse, Sergio Luis Parra-Angarita, El Khadir Lakhal, Ali Idlimam, El Houssayne Bougayr and Angélique Léonard
Appl. Sci. 2025, 15(7), 3470; https://doi.org/10.3390/app15073470 - 21 Mar 2025
Viewed by 410
Abstract
The drying of hydroxide sludge is a critical step in its valorization process in drinking water treatment plants (WWTPs), due to the high energy requirements associated with this operation. This study investigates the convective drying behavior of hydroxide sludge using a convective micro-dryer, [...] Read more.
The drying of hydroxide sludge is a critical step in its valorization process in drinking water treatment plants (WWTPs), due to the high energy requirements associated with this operation. This study investigates the convective drying behavior of hydroxide sludge using a convective micro-dryer, with air heated to temperatures between 70 °C and 110 °C, velocities ranging from 1 m/s to 3 m/s, and constant absolute humidity of 0.005 kg of water per kg of dry air. The process was continuously monitored through X-ray microtomography, allowing the nondestructive observation of external surface texture evolution, shrinkage, and crack formation. A significant shrinkage, with a volume reduction ranging from 30% to 45%, was observed as the moisture content decreased. The experimental data were used to develop a characteristic drying curve specific to hydroxide sludge, which remained consistent across different operational conditions. The results showed that increasing air temperature and velocity enhanced the drying flux and reduced drying time, while higher air humidity produced the opposite effect. Additionally, the crack formation observed towards the end of the drying process was associated with internal moisture transfer limitations. Effective diffusivity increased with air temperature, highlighting the significant impact of temperature on the activation energy of the drying process. These findings provide valuable insights for optimizing the energy efficiency of sludge-drying operations. Full article
(This article belongs to the Special Issue New Approaches to Water Treatment: Challenges and Trends)
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15 pages, 3780 KiB  
Article
Evaluation of Various Drying Methods for Mexican Yahualica chili: Drying Characteristics and Quality Assessment
by Diana Paola García-Moreira, Neith Pacheco, Harumi Hernández-Guzmán, Younes Bahammou, Zakaria Tagnamas, Ivan Moreno and Erick César López-Vidaña
Processes 2024, 12(9), 1969; https://doi.org/10.3390/pr12091969 - 13 Sep 2024
Cited by 4 | Viewed by 1406
Abstract
As one of the main chili varieties in Mexico, Yahualica chili requires year-round availability. This study examines the feasibility of five drying methods (open-air, solar, microwave, freeze-drying and shade drying) used to preserve this culturally and economically valuable product. The results show the [...] Read more.
As one of the main chili varieties in Mexico, Yahualica chili requires year-round availability. This study examines the feasibility of five drying methods (open-air, solar, microwave, freeze-drying and shade drying) used to preserve this culturally and economically valuable product. The results show the drying duration and rate for solar drying with varying air temperatures (40, 50, 60, and 70 °C) and airflows (150, 200, 250, and 300 m3/h) and microwave drying with varying power levels (90, 160, 360, and 600 W). Convection drying efficiency increased with temperature and airflow, according to the findings. Microwave drying significantly reduced drying time, and higher powers further accelerated moisture removal. Open sun and shade drying was the slowest, and open sun drying was also susceptible to factors compromising quality. Total Phenolic Content (TPC), Total Capsaicinoids Content (TCC), and antioxidant activity had a positive effect, since the drying methodologies favored the release of these compounds. Full article
(This article belongs to the Special Issue Advanced Drying Technologies in Food Processing)
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19 pages, 4858 KiB  
Article
Lady’s Mantle Flower as a Biodegradable Plant-Based Corrosion Inhibitor for CO2 Carbon Steel Corrosion
by Katarina Žbulj, Gordana Bilić, Katarina Simon and Lidia Hrnčević
Coatings 2024, 14(6), 671; https://doi.org/10.3390/coatings14060671 - 25 May 2024
Cited by 3 | Viewed by 1416
Abstract
Due to issues with the corrosion problem in the petroleum industry and the use of less ecologically acceptable corrosion inhibitors, great emphasis, within research on corrosion inhibitors, is now being put on green corrosion inhibitors (GCIs). In this study, Lady’s mantle flower extract [...] Read more.
Due to issues with the corrosion problem in the petroleum industry and the use of less ecologically acceptable corrosion inhibitors, great emphasis, within research on corrosion inhibitors, is now being put on green corrosion inhibitors (GCIs). In this study, Lady’s mantle flower extract (LMFE) has been observed as a plant-based GCI for carbon steel in a simulated CO2-saturated brine solution. The effectiveness of the inhibitor in static and flow conditions has been determined using potentiodynamic polarization with Tafel extrapolation and electrochemical impedance spectroscopy (EIS). In static conditions, the inhibitor has been tested at concentrations from 1 g/L to 5 g/L with an increment of 1 g/L per measurement, while, in dynamic (flow) conditions, the inhibitor has been tested at concentrations from 3 g/L to 6 g/L with an increment of 1 g/L per measurement. All measurements were performed at room temperature. EIS and potentiodynamic polarization methods showed that LMFE achieves maximum effectiveness in protecting carbon steel from corrosion when added at a concentration of 4 g/L in static conditions and at a concentration of 5 g/L in flow conditions. The test methods proved that the inhibitory effectiveness of LMFE is greater than 90% in both test conditions (static and flow). The inhibitor efficiency was attributed to the adsorption of LMFE on the carbon steel surface, which was demonstrated by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). A biodegradability of 0.96 and a toxicity of 19.34% for LMFE were determined. The conducted laboratory tests indicate that LMFE could be used as an effective corrosion inhibitor for CO2 carbon steel corrosion. Full article
(This article belongs to the Special Issue Investigation on Corrosion Behaviour of Metallic Materials)
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22 pages, 3464 KiB  
Article
Assessment of GPM Satellite Precipitation Performance after Bias Correction, for Hydrological Modeling in a Semi-Arid Watershed (High Atlas Mountain, Morocco)
by Myriam Benkirane, Abdelhakim Amazirh, Nour-Eddine Laftouhi, Saïd Khabba and Abdelghani Chehbouni
Atmosphere 2023, 14(5), 794; https://doi.org/10.3390/atmos14050794 - 27 Apr 2023
Cited by 7 | Viewed by 2643
Abstract
Due to its important spatiotemporal variability, accurate rainfall monitoring is one of the most difficult issues in semi-arid mountainous environments. Moreover, due to the inconsistent distribution of gauge measurement, the availability of precipitation data is not always secured and totally reliable at the [...] Read more.
Due to its important spatiotemporal variability, accurate rainfall monitoring is one of the most difficult issues in semi-arid mountainous environments. Moreover, due to the inconsistent distribution of gauge measurement, the availability of precipitation data is not always secured and totally reliable at the instantaneous time step. As a result, earth observation of precipitation estimations could be an alternative for overcoming this restriction. The current study presents a framework for either the hydro-statistical evaluation and bias correction of the Global Precipitation Measurement (GPM) Integrated Multi-SatellitE Retrievals version 06 Early (IMERG-E), Late (IMERG-L), and Final (IMERG-F) products. On a sub-daily duration, from the Taferiat rain gauge-based station, which was used as a benchmark from 1 September 2014 to 31 August 2018. Statistical analysis was performed to examine each precipitation product’s performance. The results showed that all Post_Real_Time and Real_Time IMERG had a high level of awareness accuracy. The IMERG-L results were statistically similar to the gauge data, succeeded by the IMERG-F and IMERG-E. The Cumulative Distribution Function (CDF) has been employed to adjust the precipitation values of the three IMERG products in order to decrease bias estimation. The three products were then integrated into the “HEC-HMS” hydrological model to assess their dependability in flow modeling. Six flood occurrences were calibrated and validated for each product at 30-minute time steps. With a mean Nash-Sutcliffe coefficient of NSE 0.82, the calibration findings demonstrate that IMERG-F provides satisfactory hydrological performance. With an NSE = 0.80, IMERG-L displayed good hydrological utility, slightly better than IMERG-E with an NSE = 0.77. However, when the flood events were validated using the initial soil conditions, IMERG F and IMERG E overestimated the discharge by 13% and 10%, respectively. While IMERG L passed the validation phase with an average score of NSE = 0.69. Full article
(This article belongs to the Special Issue Advances in Hydrometeorological Ensemble Prediction)
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21 pages, 28395 KiB  
Article
Machine-Learning-Based Downscaling of Hourly ERA5-Land Air Temperature over Mountainous Regions
by Badr-eddine Sebbar, Saïd Khabba, Olivier Merlin, Vincent Simonneaux, Chouaib El Hachimi, Mohamed Hakim Kharrou and Abdelghani Chehbouni
Atmosphere 2023, 14(4), 610; https://doi.org/10.3390/atmos14040610 - 23 Mar 2023
Cited by 27 | Viewed by 6087
Abstract
In mountainous regions, the scarcity of air temperature (Ta) measurements is a major limitation for hydrological and crop monitoring. An alternative to in situ measurements could be to downscale the reanalysis Ta data provided at high-temporal resolution. However, the relatively coarse spatial resolution [...] Read more.
In mountainous regions, the scarcity of air temperature (Ta) measurements is a major limitation for hydrological and crop monitoring. An alternative to in situ measurements could be to downscale the reanalysis Ta data provided at high-temporal resolution. However, the relatively coarse spatial resolution of these products (i.e., 9 km for ERA5-Land) is unlikely to be directly representative of actual local Ta patterns. To address this issue, this study presents a new spatial downscaling strategy of hourly ERA5-Land Ta data with a three-step procedure. First, the 9 km resolution ERA5 Ta is corrected at its original resolution by using a reference Ta derived from the elevation of the 9 km resolution grid and an in situ estimate over the area of the hourly Environmental Lapse Rate (ELR). Such a correction of 9 km resolution ERA5 Ta is trained using several machine learning techniques, including Multiple Linear Regression (MLR), Support Vector Regression (SVR), and Extreme Gradient Boosting (Xgboost), as well as ancillary ERA5 data (daily mean, standard deviation, hourly ELR, and grid elevation). Next, the trained correction algorithms are run to correct 9 km resolution ERA5 Ta, and the corrected ERA5 Ta data are used to derive an updated ELR over the area (without using in situ Ta measurements). Third, the updated hourly ELR is used to disaggregate 9 km resolution corrected ERA5 Ta data at the 30-meter resolution of SRTM’s Digital Elevation Model (DEM). The effectiveness of this method is assessed across the northern part of the High Atlas Mountains in central Morocco through (1) k-fold cross-validation against five years (2016 to 2020) of in situ hourly temperature readings and (2) comparison with classical downscaling methods based on a constant ELR. Our results indicate a significant enhancement in the spatial distribution of hourly local Ta. By comparing our model, which included Xgboost, SVR, and MLR, with the constant ELR-based downscaling approach, we were able to decrease the regional root mean square error from approximately 3 C to 1.61 C, 1.75 C, and 1.8 C, reduce the mean bias error from −0.5 C to null, and increase the coefficient of determination from 0.88 to 0.97, 0.96, and 0.96 for Xgboost, SVR, and MLR, respectively. Full article
(This article belongs to the Special Issue Statistical Approaches in Climatic Parameters Prediction)
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15 pages, 2402 KiB  
Article
Rheological Behavior and Characterization of Drinking Water Treatment Sludge from Morocco
by Fantasse Azeddine, Parra Angarita Sergio, Léonard Angélique, Lakhal El Khadir, Idlimam Ali and Bougayr El Houssayne
Clean Technol. 2023, 5(1), 259-273; https://doi.org/10.3390/cleantechnol5010015 - 16 Feb 2023
Cited by 13 | Viewed by 3567
Abstract
Drinking water treatment generates a high amount of pasty by-product known as drinking water treatment sludge (DWTS). The chemical composition, microstructure and rheological behavior of DWTS are of utmost importance in the calculation, design, optimization, commissioning and control of its treatment processes. The [...] Read more.
Drinking water treatment generates a high amount of pasty by-product known as drinking water treatment sludge (DWTS). The chemical composition, microstructure and rheological behavior of DWTS are of utmost importance in the calculation, design, optimization, commissioning and control of its treatment processes. The purpose of this research was to characterize the DWTS from the drinking water treatment plant of Marrakech (Morocco), aiming to help future researchers and engineers in predicting its hydrodynamic behavior. The first part of this study was devoted to the physical structure and the chemical composition of sludge. The second part was oriented towards the study of the mechanical properties; a penetration test and a rotational rheology test were performed. For the first test, a force–length penetration diagram was plotted in order to calculate the hardness, the cohesiveness and the adhesiveness of DWTS. For the second test, the shear stress and the apparent viscosity were plotted and fitted to five rheological models, as function of the shear rate, aiming to describe the rheological behavior of samples. The obtained results reveal that the drinking water treatment sludge from Marrakech is a porous, amorphous and highly adhesive material, with a shear-thinning (pseudoplastic) rheological behavior that can be described according to the Herschel–Bulkley model (better in low-rate stresses, R² = 0.98) or the Windhad model (better in high shear rates, R² = 0.96) and is mainly composed of silica, aluminum and iron oxides. Full article
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22 pages, 6524 KiB  
Article
Smart Weather Data Management Based on Artificial Intelligence and Big Data Analytics for Precision Agriculture
by Chouaib El Hachimi, Salwa Belaqziz, Saïd Khabba, Badreddine Sebbar, Driss Dhiba and Abdelghani Chehbouni
Agriculture 2023, 13(1), 95; https://doi.org/10.3390/agriculture13010095 - 29 Dec 2022
Cited by 50 | Viewed by 15738
Abstract
Smart management of weather data is an essential step toward implementing sustainability and precision in agriculture. It represents an important input for numerous tasks, such as crop growth, development, yield, and irrigation scheduling, to name a few. Advances in technology allow collecting this [...] Read more.
Smart management of weather data is an essential step toward implementing sustainability and precision in agriculture. It represents an important input for numerous tasks, such as crop growth, development, yield, and irrigation scheduling, to name a few. Advances in technology allow collecting this weather data from heterogeneous sources with high temporal resolution and at low cost. Generating and using these data in their raw form makes no sense, and therefore implementing adequate infrastructure and tools is necessary. For that purpose, this paper presents a smart weather data management system evaluated using data from a meteorological station installed in our study area covering the period from 2013 to 2020 at a half-hourly scale. The proposed system makes use of state-of-the-art statistical methods, machine learning, and deep learning models to derive actionable insights from these raw data. The general architecture is made up of four layers: data acquisition, data storage, data processing, and application layers. The data sources include real-time sensors, IoT devices, reanalysis data, and raw files. The data are then checked for errors and missing values using a proposed method based on ERA5-Land reanalysis data and deep learning. The resulting coefficient of determination (R2) and Root Mean Squared Error (RMSE) for this method were 0.96 and 0.04, respectively, for the scaled air temperature estimate. The MongoDB NoSQL database is used for storage thanks to its ability to deal with real-world big data. The system offers various services such as (i) weather time series forecasts, (ii) visualization and analysis of meteorological data, and (iii) the use of machine learning to estimate the reference evapotranspiration (ET0) needed for efficient irrigation. To this, the platform uses the XGBoost model to achieve the precision of the Penman–Monteith method while using a limited number of meteorological variables (air temperature and global solar radiation). Results for this approach give R2 = 0.97 and RMSE = 0.07. This system represents the first incremental step toward implementing smart and sustainable agriculture in Morocco. Full article
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24 pages, 7075 KiB  
Article
Medium-Resolution Mapping of Evapotranspiration at the Catchment Scale Based on Thermal Infrared MODIS Data and ERA-Interim Reanalysis over North Africa
by Alhousseine Diarra, Lionel Jarlan, Saïd Khabba, Michel Le Page, Salah Er-Raki, Riad Balaghi, Soufyane Charafi, Abdelghani Chehbouni and Rafiq El Alami
Remote Sens. 2022, 14(20), 5071; https://doi.org/10.3390/rs14205071 - 11 Oct 2022
Cited by 4 | Viewed by 3069
Abstract
Accurate quantification of evapotranspiration (ET) at the watershed scale remains an important research challenge for managing water resources in arid and semiarid areas. In this study, daily latent heat flux (LE) maps at the kilometer scale were derived from the two-source energy budget [...] Read more.
Accurate quantification of evapotranspiration (ET) at the watershed scale remains an important research challenge for managing water resources in arid and semiarid areas. In this study, daily latent heat flux (LE) maps at the kilometer scale were derived from the two-source energy budget (TSEB) model fed by the MODIS leaf area index (LAI), land surface temperature (LST) products, and meteorological data from ERA-Interim reanalysis from 2001 to 2015 on the Tensift catchment (center of Morocco). As a preliminary step, both ERA-Interim and predicted LE at the time of the satellite overpass are evaluated in comparison to a large database of in situ meteorological measurements and eddy covariance (EC) observations, respectively. ERA-Interim compared reasonably well to in situ measurements, but a positive bias on air temperature was highlighted because meteorological stations used for the evaluation were mainly installed on irrigated fields while the grid point of ERA-Interim is representative of larger areas including bare (and hot) soil. Likewise, the predicted LE was in good agreement with the EC measurements gathered on the main crops of the region during 15 agricultural seasons with a correlation coefficient r = 0.70 and a reasonable bias of 30 W/m2. After extrapolating the instantaneous LE estimates to ET daily values, monthly ET was then assessed in comparison to monthly irrigation water amounts provided by the local agricultural office added to CRU precipitation dataset with a reasonable agreement; the relative error was more than 89% but the correlation coefficient r reached 0.80. Seasonal and interannual evapotranspiration was analyzed in relation to local climate and land use. Lastly, the potential use for improving the early prediction of grain yield, as well as detecting newly irrigated areas for arboriculture, is also discussed. The proposed method provides a relatively simple way for obtaining spatially distributed daily estimates of ET at the watershed scale, especially for not ungauged catchments. Full article
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17 pages, 3960 KiB  
Article
Hydro Statistical Assessment of TRMM and GPM Precipitation Products against Ground Precipitation over a Mediterranean Mountainous Watershed (in the Moroccan High Atlas)
by Myriam Benkirane, Nour-Eddine Laftouhi, Saïd Khabba and África de la Hera-Portillo
Appl. Sci. 2022, 12(16), 8309; https://doi.org/10.3390/app12168309 - 19 Aug 2022
Cited by 6 | Viewed by 2208
Abstract
The tropical Rainfall Measuring Mission TRMM 3B42 V7 product and its successor, the Global Precipitation Measurement Integrated Multi-satellitE Retrievals for GPM IMERG high-resolution product GPM IMERG V5, have been validated against rain gauges precipitation in an arid mountainous basin where ground-based observations of [...] Read more.
The tropical Rainfall Measuring Mission TRMM 3B42 V7 product and its successor, the Global Precipitation Measurement Integrated Multi-satellitE Retrievals for GPM IMERG high-resolution product GPM IMERG V5, have been validated against rain gauges precipitation in an arid mountainous basin where ground-based observations of precipitation are sparse, or spatially undistributed. This paper aims to evaluate hydro-statically the performances of the TRMM 3B42 V7 and GPM IMERG V05 satellite precipitations products SPPs, at multiple temporal scales, from 2014 to 2017. SPPs are compared with the gauge station and show good results for both statistical and contingency metrics with notable values R > 0.94. Moreover, the rainfall-runoff events implemented on the hydrological model were performed at 3-hourly time steps and showed satisfactory results based on the obtained Nash–Sutcliffe criteria ranging from 94.50% to 57.50%, and from 89.3% to 51.2%, respectively. The TRMM product tends to underestimate and not capture extreme precipitation events. In contrast, the GPM product can identify the variability of precipitation at small time steps, although a slight underestimation in the detection of extreme events can be corrected during the validation steps. The proposed method is an interesting approach for solving the problem of insufficient observed data in the Mediterranean regions. Full article
(This article belongs to the Special Issue Geomorphology in the Digital Era)
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7 pages, 1563 KiB  
Proceeding Paper
Towards Smart Big Weather Data Management
by Chouaib EL Hachimi, Salwa Belaqziz, Saïd Khabba and Abdelghani Chehbouni
Chem. Proc. 2022, 10(1), 54; https://doi.org/10.3390/IOCAG2022-12240 - 10 Feb 2022
Cited by 2 | Viewed by 1553
Abstract
Smart management of weather data is pivotal to achieving sustainable agriculture since weather monitoring is linked to crop water requirement estimation and consequently to efficient irrigation systems. Advances in technologies such as remote sensing and the Internet of Things (IoT) have led to [...] Read more.
Smart management of weather data is pivotal to achieving sustainable agriculture since weather monitoring is linked to crop water requirement estimation and consequently to efficient irrigation systems. Advances in technologies such as remote sensing and the Internet of Things (IoT) have led to the generation of this data with a high temporal resolution which requires adequate infrastructure and processing tools to gain insights from it. To this end, this paper presents a smart weather data management system composed of three layers: the data acquisition layer, the data storage layer, and the application layer. The data can be sourced from station sensors, real-time IoT sensors, third-party services (APIs), or manually imported from files. It is then checked for errors and missing values before being stored using the distributed database MongoDB. The platform provides various services related to weather data: (i) forecast univariate weather time series, (ii) perform advanced analysis and visualization, (iii) use machine learning to estimate and model important climatic parameters such as the reference evapotranspiration (ET0) estimation using the XGBoost model (R2 = 0.96 and RMSE = 0.39). As part of a test phase, the system uses data from a meteorological station installed in the study area in Morocco. Full article
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26 pages, 4402 KiB  
Article
A Calibration/Disaggregation Coupling Scheme for Retrieving Soil Moisture at High Spatio-Temporal Resolution: Synergy between SMAP Passive Microwave, MODIS/Landsat Optical/Thermal and Sentinel-1 Radar Data
by Nitu Ojha, Olivier Merlin, Abdelhakim Amazirh, Nadia Ouaadi, Vincent Rivalland, Lionel Jarlan, Salah Er-Raki and Maria Jose Escorihuela
Sensors 2021, 21(21), 7406; https://doi.org/10.3390/s21217406 - 8 Nov 2021
Cited by 4 | Viewed by 3078
Abstract
Soil moisture (SM) data are required at high spatio-temporal resolution—typically the crop field scale every 3–6 days—for agricultural and hydrological purposes. To provide such high-resolution SM data, many remote sensing methods have been developed from passive microwave, active microwave and thermal data. Despite [...] Read more.
Soil moisture (SM) data are required at high spatio-temporal resolution—typically the crop field scale every 3–6 days—for agricultural and hydrological purposes. To provide such high-resolution SM data, many remote sensing methods have been developed from passive microwave, active microwave and thermal data. Despite the pros and cons of each technique in terms of spatio-temporal resolution and their sensitivity to perturbing factors such as vegetation cover, soil roughness and meteorological conditions, there is currently no synergistic approach that takes advantage of all relevant (passive, active microwave and thermal) remote sensing data. In this context, the objective of the paper is to develop a new algorithm that combines SMAP L-band passive microwave, MODIS/Landsat optical/thermal and Sentinel-1 C-band radar data to provide SM data at the field scale at the observation frequency of Sentinel-1. In practice, it is a three-step procedure in which: (1) the 36 km resolution SMAP SM data are disaggregated at 100 m resolution using MODIS/Landsat optical/thermal data on clear sky days, (2) the 100 m resolution disaggregated SM data set is used to calibrate a radar-based SM retrieval model and (3) the so-calibrated radar model is run at field scale on each Sentinel-1 overpass. The calibration approach also uses a vegetation descriptor as ancillary data that is derived either from optical (Sentinel-2) or radar (Sentinel-1) data. Two radar models (an empirical linear regression model and a non-linear semi-empirical formulation derived from the water cloud model) are tested using three vegetation descriptors (NDVI, polarization ratio (PR) and radar coherence (CO)) separately. Both models are applied over three experimental irrigated and rainfed wheat crop sites in central Morocco. The field-scale temporal correlation between predicted and in situ SM is in the range of 0.66–0.81 depending on the retrieval configuration. Based on this data set, the linear radar model using PR as a vegetation descriptor offers a relatively good compromise between precision and robustness all throughout the agricultural season with only three parameters to set. The proposed synergistical approach combining multi-resolution/multi-sensor SM-relevant data offers the advantage of not requiring in situ measurements for calibration. Full article
(This article belongs to the Special Issue Applications and Downscaling of Remote Sensing Soil Moisture)
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26 pages, 2000 KiB  
Review
A Review of Irrigation Information Retrievals from Space and Their Utility for Users
by Christian Massari, Sara Modanesi, Jacopo Dari, Alexander Gruber, Gabrielle J. M. De Lannoy, Manuela Girotto, Pere Quintana-Seguí, Michel Le Page, Lionel Jarlan, Mehrez Zribi, Nadia Ouaadi, Mariëtte Vreugdenhil, Luca Zappa, Wouter Dorigo, Wolfgang Wagner, Joost Brombacher, Henk Pelgrum, Pauline Jaquot, Vahid Freeman, Espen Volden, Diego Fernandez Prieto, Angelica Tarpanelli, Silvia Barbetta and Luca Broccaadd Show full author list remove Hide full author list
Remote Sens. 2021, 13(20), 4112; https://doi.org/10.3390/rs13204112 - 14 Oct 2021
Cited by 111 | Viewed by 13906
Abstract
Irrigation represents one of the most impactful human interventions in the terrestrial water cycle. Knowing the distribution and extent of irrigated areas as well as the amount of water used for irrigation plays a central role in modeling irrigation water requirements and quantifying [...] Read more.
Irrigation represents one of the most impactful human interventions in the terrestrial water cycle. Knowing the distribution and extent of irrigated areas as well as the amount of water used for irrigation plays a central role in modeling irrigation water requirements and quantifying the impact of irrigation on regional climate, river discharge, and groundwater depletion. Obtaining high-quality global information about irrigation is challenging, especially in terms of quantification of the water actually used for irrigation. Here, we review existing Earth observation datasets, models, and algorithms used for irrigation mapping and quantification from the field to the global scale. The current observation capacities are confronted with the results of a survey on user requirements on satellite-observed irrigation for agricultural water resources’ management. Based on this information, we identify current shortcomings of irrigation monitoring capabilities from space and phrase guidelines for potential future satellite missions and observation strategies. Full article
(This article belongs to the Special Issue Irrigation Mapping Using Satellite Remote Sensing)
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27 pages, 6309 KiB  
Article
Optimizing the Sowing Date to Improve Water Management and Wheat Yield in a Large Irrigation Scheme, through a Remote Sensing and an Evolution Strategy-Based Approach
by Salwa Belaqziz, Saïd Khabba, Mohamed Hakim Kharrou, El Houssaine Bouras, Salah Er-Raki and Abdelghani Chehbouni
Remote Sens. 2021, 13(18), 3789; https://doi.org/10.3390/rs13183789 - 21 Sep 2021
Cited by 19 | Viewed by 4327
Abstract
This study aims to investigate the effects of an optimized sowing calendar for wheat over a surface irrigation scheme in the semi-arid region of Haouz (Morocco) on irrigation water requirements, crop growth and development and on yield. For that, a scenario-based simulation approach [...] Read more.
This study aims to investigate the effects of an optimized sowing calendar for wheat over a surface irrigation scheme in the semi-arid region of Haouz (Morocco) on irrigation water requirements, crop growth and development and on yield. For that, a scenario-based simulation approach based on the covariance matrix adaptation–evolution strategy (CMA-ES) was proposed to optimize both the spatiotemporal distribution of sowing dates and the irrigation schedules, and then evaluate wheat crop using the 2011–2012 growing season dataset. Six sowing scenarios were simulated and compared to identify the most optimal spatiotemporal sowing calendar. The obtained results showed that with reference to the existing sowing patterns, early sowing of wheat leads to higher yields compared to late sowing (from 7.40 to 5.32 t/ha). Compared with actual conditions in the study area, the spatial heterogeneity is highly reduced, which increased equity between farmers. The results also showed that the proportion of plots irrigated in time can be increased (from 40% to 82%) compared to both the actual irrigation schedules and to previous results of irrigation optimization, which did not take into consideration sowing dates optimization. Furthermore, considerable reduction of more than 40% of applied irrigation water can be achieved by optimizing sowing dates. Thus, the proposed approach in this study is relevant for irrigation managers and farmers since it provides an insight on the consequences of their agricultural practices regarding the wheat sowing calendar and irrigation scheduling and can be implemented to recommend the best practices to adopt. Full article
(This article belongs to the Special Issue Remote Sensing in Irrigated Crop Water Stress Assessment)
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21 pages, 2853 KiB  
Article
Cereal Yield Forecasting with Satellite Drought-Based Indices, Weather Data and Regional Climate Indices Using Machine Learning in Morocco
by El houssaine Bouras, Lionel Jarlan, Salah Er-Raki, Riad Balaghi, Abdelhakim Amazirh, Bastien Richard and Saïd Khabba
Remote Sens. 2021, 13(16), 3101; https://doi.org/10.3390/rs13163101 - 6 Aug 2021
Cited by 70 | Viewed by 8781
Abstract
Accurate seasonal forecasting of cereal yields is an important decision support tool for countries, such as Morocco, that are not self-sufficient in order to predict, as early as possible, importation needs. This study aims to develop an early forecasting model of cereal yields [...] Read more.
Accurate seasonal forecasting of cereal yields is an important decision support tool for countries, such as Morocco, that are not self-sufficient in order to predict, as early as possible, importation needs. This study aims to develop an early forecasting model of cereal yields (soft wheat, barley and durum wheat) at the scale of the agricultural province considering the 15 most productive over 2000–2017 (i.e., 15 × 18 = 270 yields values). To this objective, we built on previous works that showed a tight linkage between cereal yields and various datasets including weather data (rainfall and air temperature), regional climate indices (North Atlantic Oscillation in particular), and drought indices derived from satellite observations in different wavelengths. The combination of the latter three data sets is assessed to predict cereal yields using linear (Multiple Linear Regression, MLR) and non-linear (Support Vector Machine, SVM; Random Forest, RF, and eXtreme Gradient Boost, XGBoost) machine learning algorithms. The calibration of the algorithmic parameters of the different approaches are carried out using a 5-fold cross validation technique and a leave-one-out method is implemented for model validation. The statistical metrics of the models are first analyzed as a function of the input datasets that are used, and as a function of the lead times, from 4 months to 2 months before harvest. The results show that combining data from multiple sources outperformed models based on one dataset only. In addition, the satellite drought indices are a major source of information for cereal prediction when the forecasting is carried out close to harvest (2 months before), while weather data and, to a lesser extent, climate indices, are key variables for earlier predictions. The best models can accurately predict yield in January (4 months before harvest) with an R2 = 0.88 and RMSE around 0.22 t. ha−1. The XGBoost method exhibited the best metrics. Finally, training a specific model separately for each group of provinces, instead of one global model, improved the prediction performance by reducing the RMSE by 10% to 35% depending on the provinces. In conclusion, the results of this study pointed out that combining remote sensing drought indices with climate and weather variables using a machine learning technique is a promising approach for cereal yield forecasting. Full article
(This article belongs to the Special Issue Advances in Remote Sensing for Crop Monitoring and Yield Estimation)
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