Semi-arid Mediterranean Climate Research Articles

Typology and classification of water quality in an intermittent river in a semi-arid Mediterranean climate.

The typology and classification of rivers are highly relevant concepts in the field of limnology and freshwater ecology. Water body typology systematically categorizes water bodies based on their natural attributes, while water body classification groups them based on specific criteria or purposes for management, regulatory, or administrative reasons. Both concepts play important roles in understanding and managing water resources effectively. This scientific article focuses on the ZAT River in Morocco as a model for studying low-flow and intermittent rivers. The objective is to develop an accurate model for the typology and classification of small, low-flow rivers into homogeneous classes based on natural and anthropogenic factors. The study also investigates the impact of human activities on altering the uniformity and reference nature of the water body. The typology of water bodies is carried out according to the European methodology specified in The European Commission's Water Framework Directive (WFD) in 2000. The classification of water bodies is conducted by assessing their chemical and biological quality using the weighted index (WI), the Iberian Biological Monitoring Working Group (IBMWP) index, and multivariate statistical methods such as principal component analysis (PCA) for confirming water quality assessment. The results indicate the possibility of dividing the basin into four water bodies. Water bodies show homogeneity in terms of chemical quality when human influence is minimal or during periods of high river flow. However, increased human influence and decreased river flows lead to heterogeneity in chemical quality, indicating an unstable state. This study is the first of its kind in arid and semi-arid intermittent rivers, where such an approach could be suggested to determine their typology and classification.

Inter-relations of precipitation, aerosols, and clouds over Andalusia, southern Spain, revealed by the Andalusian Global ObseRvatory of the Atmosphere (AGORA)

Abstract. The south-central interior of Andalusia experiences intricate precipitation patterns as a result of its semi-arid Mediterranean climate and the impact of Saharan dust and human-made pollutants. The primary aim of this study is to monitor the inter-relations between various factors, such as aerosols, clouds, and meteorological variables, and precipitation systems in Granada using ground-based remote sensing and in situ instruments including a microwave radiometer, ceilometer, cloud radar, nephelometer, and weather station. Over an 11-year period, we detected rain events using a physical retrieval method that employed microwave radiometer measurements. A composite analysis was applied to them to construct a climatology of the temporal evolution of precipitation. It was found that convective rain is the dominant precipitation type in Granada, accounting for 68 % of the rain events. The height of the cloud base is mainly distributed at an altitude of 2 to 7 km. Integrated water vapor (IWV) and integrated cloud liquid water (ILW) increase rapidly before the onset of rain. Aerosol scattering at the surface level and hence the aerosol concentration are reduced during rain, and the predominant mean size distribution of aerosol particles before, during, and after rain is almost the same. A meteorological environment favorable for virga formation is observed in Granada. The surface weather station detected rainfall later than the microwave radiometer, indicating virga according to ceilometer and cloud radar data. We used 889 rain-day events identified by weather station data to determine precipitation intensity classes and found that light rain is the main precipitation intensity class in Granada, accounting for 72 % of the rain-day events. This can be a result of the high tropospheric temperature induced by the Andalusian climate and the reduction of cloud droplet size by the high availability of aerosol particles in the urban atmosphere. This study provides evidence that aerosols, clouds, and meteorological variables have a combined impact on precipitation which can be considered for water resource management and improving rain forecasting accuracy.

Use of “Glass Curtain” Systems to Improve the Energy Efficiency and Thermal Comfort of Dwellings in a Warm Semi-Arid Mediterranean Climate

The dry Mediterranean climate (BShs) within a warm semi-arid climate (BSh) is the zone in Europe with the most annual hours of sunlight, and it has a smaller annual temperature variation than most climates. This allows the greenhouse effect caused by windows to be used to heat dwellings in winter. Balcony frameless retractable glazing systems known as “glass curtain” systems offer the highest proportion of glass and maximum openness in the façade, allowing for maximum sunlight and ventilation. This work studies a glazed terrace with a “glass curtain” in a dwelling on the Spanish Mediterranean coastline. The objective is to quantitatively determine the enhancement of the thermal comfort and energy efficiency of a dwelling using “glass curtain” systems. The modification of several design parameters of the glazed terrace is also analysed. The novelty of this study lies in demonstrating that the use and optimised design of “glass curtain” systems allows us to obtain nearly zero-energy buildings (nZEBs) and thermally comfortable dwellings all year round. The research methods include a comparison of the current thermal performance of the dwelling with and without a “glass curtain” system via on-site measurements. The study also evaluates the influence of modifying design parameters using computer simulations. The results show that “glass curtain” systems increase the indoor temperatures inside the dwelling by about 4 °C in winter and reduce the annual indoor thermal oscillation from more than 16 °C to only 10 °C. Consequently, such systems reduce heating energy needs by almost 60%. Glazed terraces using the proposed design parameters show further improvement regarding thermal comfort and practically eliminate heating and cooling needs.

Basal defoliation, salicylic acid and cyanocobalamin to ameliorate the physiological and biochemical characteristics of flood-irrigated ‘Crimson Seedless’ grapevines in a semi-arid Mediterranean climate

ABSTRACT There is a high retail demand for ‘Crimson Seedless’ grape. Cluster shape, berry size, colour, and sugar contents influence the overall fruit quality and marketability. In many commercial vineyards of flood-irrigated clay soils under warm and humid semi-arid climates, adequate irrigation may lead to an enhanced fruit set that could potentially be associated with restricted berry growth, compact clusters, and poor berry colour and taste. To assess the role of some agronomic practices that may influence the canopy microclimate, and affect primary and secondary metabolites, seven treatments arranged in a randomised complete block design (RCBD) system with three replicates each (three vines per replicate) were applied as follow; the control (T1), 5-leaf basal defoliation at pre-bloom (BDPB) (T2), BDPB + foliar spray (FS) of 200 mg · L–1 salicylic acid (SA) (T3), BDPB + FS of 20 mg · L–1 cyanocobalamin (CCA) (T4), 5-leaf basal defoliation at full bloom (BDFB) (T5), BDFP + SA (T6) and BDFB + CCA (T7). Foliar applications were applied at 1) 2 weeks after the beginning of vegetative growth, 2) full bloom and 3) veraison stages. The analysis of variance (ANOVA), the principle component analysis (PCA) and the two-way hierarchical cluster analysis (HCA) indicated that BDPB (T2) generally has a better effect than that of BDFB (T5). The most pronounced effect on vegetative growth (shoot length and leaf area), photosynthesis activity (leaf chlorophyll and carbohydrate contents), fruit weight and dimensions, and total yield was observed in the case of T3, followed by T6, whereas concerning berry firmness, colour (anthocyanins) and sensory characteristics (soluble solids: acids ratio, total sugars and phenols), the most pronounced effect was observed in the case of T4, followed by T7.

Spatiotemporal analysis of transition probabilities of wet and dry days under SSPs scenarios in the semi-arid Susurluk Basin, Türkiye

Precipitation, especially in regions dominated by the Mediterranean climate, is one of the most critical parameters of the hydrological cycle and the environment affected by climate change. One the one hand, the transition probabilities of wet and dry days in precipitation occurrence are a relatively new topic, on the other hand these are essential in defining the regional climate. For the first time, spatiotemporal variations of transition probabilities of wet and dry days in the Susurluk Basin, northwestern Türkiye, dominated by a semi-arid Mediterranean climate and also having a mountain climate, were analyzed based on the observation (1979–2014) and future terms (2030–2059 as short and 2070–2099 as long), under four Shared Socioeconomic Pathways (SSPs) scenarios. To do this, statistical downscaling was performed for 14 general circulation models (GCMs) from the CMIP6. By applying an ensemble of four high-performing GCMs, four indices for transition probabilities of wet and dry, i.e., a dry day following a dry day (FDD), a wet day following a dry day (FDW), a dry day following a wet day (FWD), and a wet day following a wet day (FWW), were calculated, and their changes were determined statistically. Monotonic and partial trends of the indices were also analyzed. According to the results, the FDD will increase in water year and wet period and autumn in the future, especially for the long term, in the basin dominated by the FDD (75 % in water year). The risks are higher in the western part of the basin, where human activities are intense, as the FDD is higher in this part than other parts especially in summer (90–100 %) in SSP3-7.0 and SSP5-8.5 scenarios for the long term. So, the length of consecutive dry days in the wet period and water year will increase in the basin, thus increasing the likelihood of droughts. As for the intra-term trends, the FDD increases and the FWW decreases in the water year and seasons in SSP3-7.0 and SSP5-8.5, contrary to the observation term.

Carbon dynamics as a function of soil moisture following repeated wet-dry cycles in irrigated soils

Drying-rewetting cycles are ubiquitous across natural and managed ecosystems. These cycles are known to mobilize carbon (C) in soils producing dramatic pulses in microbial respiration. While many factors contribute to these pulses, the drying-rewetting history of soils affecting carbon emissions remains unclear, especially in irrigated soils where soil moisture fluctuations are more repetitive and/or frequent than natural, seasonally influenced soils. To understand the controls of repeated wet-up and dry down effects on agricultural soils, we used a systems approach to examine the cross section of a furrow irrigated orchard to delineate soil C dynamics. Specifically, we compared two contrasting water regimes, (1) soils temporarily but repeatedly inundated during water delivery (i.e., furrows) and (2) soils at the base of trees (i.e., berms) that only receive water during precipitation events in a semi-arid Mediterranean climate. Overall, our findings show that the heterogeneous landscape of a furrow irrigated field results in two separate systems within the field scale in gaseous release of C as CO2, microbial selectivity of substrates, and mechanisms for C stabilization. By monitoring soil moisture as a function of depth for over two years, our results reveal that furrow soils undergo dramatic wet-dry cycles, while moisture within the berm is relatively constant. We were able to capture the distinct heterogeneity of soil moisture changes within the furrow and berm soils by continuously monitoring CO2 flux throughout water input events in both the wet and dry season. Soil CO2 efflux is suppressed upon irrigation within furrows, while carbon oxidation in berm soils exhibits pore-connectivity limitations that result in lower fluxes when dry. Solid phase soil C speciation determined by C 1s NEXAFS demonstrated C of higher aromaticity remained in furrow soil compared to berm soils. Microbial community analysis shows significantly different communities reside within berm and furrow soils, where furrow soils support more anaerobic metabolisms and spore-formers while berm soils have relatively higher abundance of aerobic microbes capable of degrading larger, more complex C compounds. Our findings show that water regime (periodic inundation vs episodic rainfall) controlling rewetting history can greatly differentiate C respiration within managed soils.

Leaf Area Duration and Crop Radiation Use Efficiency Determine Biomass Yield of Lignocellulosic Perennial Grasses under Different Soil Water Content

The aim of the present work was to assess the leaf area duration (LAD) and the radiation use efficiency (RUE) of six warm-season perennial biomass grasses (PBGs) in a two-year field trial in the semiarid Mediterranean climate under different soil water availability. Two ecotypes of giant reed (Arundo donax L., ARCT and ARMO), one ecotype of African fodder cane (Saccharum spontaneum L. subsp. aegyptiacum (Willd.) Hack., SAC) and three hybrids of Miscanthus (the commercial M. × giganteus J.M. Greef, Deuter ex Hodk., Renvoize, M × G, and two new seed-based hybrids, GNT9 and GNT10) were compared under three levels of soil water availability: rainfed, 50% and 100% of maximum crop evapotranspiration (ETm) restoration. The determination of RUE of perennial plants is controversial and has led to contrasting results in past studies. In the present work, LAD and RUE differed among crops and irrigation regimes, being positively affected by supplemental water inputs. SAC, ARCT and ARMO showed both high LAD and RUE, which determined the high biomass yield than both the commercial M × G and the improved Miscanthus hybrids GNT9 and GNT10. RUE was particularly high and less affected by soil water availability during the mid-season, while the effect of irrigation and the differences among the genotypes were larger during the late season. Adequate biomass yield can be achieved by sub-optimal soil water availability, thus reducing the water footprint and increasing the sustainability of these biomass perennial grasses selected for the Mediterranean climate.

A holistic digital workflow methodology to shifting towards net zero energy urban residential buildings in a semi-arid climate

Given the looming threats of climate change and the rapid worldwide urbanization, it is a necessity to prioritize the transition towards a carbon-free built environment. This research study provides a holistic digital methodology for parametric design of urban residential buildings with regard to the Mediterranean semi-arid climate zone of Morocco in the early design phase. The morphological parameters of the urban residential buildings, namely the buildings’ typology, the distance between buildings, the urban grid’s orientation, and the window-to-wall ratio, are evaluated in order to identify the key combinations of passive and active solar design strategies that determine the high energy performing configurations, based on the introduced Energy Performance Index (EPI), which is the ratio between solar BIPV production to maximum available installed BIPV capacity and the normalized thermal energy needs. Through an automated processing of 2187 iterations via Grasshopper, we simulate daylight autonomy, indoor thermal comfort and solar rooftop photovoltaic and building integrated photovoltaic (BIPV) energy potential. Then, we analyze the conflicting objectives of energy efficiency measures, active solar design strategies, and indoor visual comfort in the decision-making process that supports our goal of getting closer to net zero urban residential buildings. The digital workflow showed interesting trends in reaching a balanced equilibrium between performance metrics influenced by the contrasting impact of solar exposure on indoor daylight autonomy and thermal energy demand. Furthermore, the study's findings indicate that it is possible to achieve an annual load match exceeding 66,56 % while simultaneously ensuring an acceptable visual indoor comfort (sDA higher than 0.4). The findings also highlight the important role of the BIPV system in shifting towards the net zero energy goal, by contributing up to 30 % of the overall solar energy output and covering up to 20 % of the yearly self-consumption. Moreover, the energy balance evaluation on an hourly basis indicates that BIPV system notably enhances the daily load cover factor by up to 5.5 %, particularly in the case of slab SN typology, throughout the different seasons.Graphical representations of the yearly, monthly and hourly load matches and the hourly energy balance of the best performing configurations provide a thorough understanding of the potential evolution of the urban energy system over time as a result of the gradual integration of active solar electricity production.

Monitoring and performance evaluation of a green wall in a semi-arid Mediterranean climate

Green walls are gaining popularity as a sustainable cladding solution for buildings, offering various advantages for the built environment and human well-being. However, there is a lack of research on plant selection guides and field data in semi-arid Mediterranean climates, limiting our understanding of green wall potential. To address these gaps, this study assesses the hygrothermal and sound insulation performance of a modular living wall in a semi-arid Mediterranean climate and develops a plant-selection guideline for green wall applications. The experiment involves a comparative assessment between the modular living wall and a bare-wall-reference facade. Measurements of air temperature, relative humidity, and sound pressure were taken, along with thermal imaging, to record the surface temperatures of the experimental facades. Results reveal that the modular-living wall significantly decreased dry-bulb air temperature (up to 8 °C) and reduced sound pressure by up to 5.1 dB. Additionally, relative humidity in the air cavity behind the modular living wall consistently increased by 6.6%, with a maximum absolute humidity differential of 8.6 g/kg. Thermal imaging showed a surface temperature difference of up to 27 °C, with foliage having a higher leaf-area-index proving more efficient in reducing the surface temperature of the green wall.Overall, the modular living wall effectively protected building walls from high solar radiation and temperatures, resulting in reduced energy requirements for space cooling. However, proper irrigation and plant health maintenance are necessary. This study fills important research gaps, providing valuable insights into the potential benefits and performance of green walls in semi-arid Mediterranean climates.

Assessment of Sidi Abed mountain flora richness through endemic, rare and threatened species in Tiaret, Algeria

To present day, no study has been carried out on the local flora of the Sidi Abed Mountain. Situated southern the city of Tiaret considered as natural barrier before steppe area. Phyto-ecological surveys with 100 m2 Braun-Blanquet minimum area were conducted 75 species, belonging to 29 families and 66 genera has been established. Asteraceae (20%), Fabaceae (10.7), Poaceae (10.7), Lamiaceae (6.7%), Apiaceae (5.3%) and Asparagaceae (5.3) were the most representative families covering more than 50% of the inventoried families. Moreover, Therophytes (48%) are majorly dominant with a notable decrease of the phanerophytes (5,3%) and increase of Hemicryptophytes (22.7%). Predominance of the Mediterranean biogeographic type species with a percentage of (41.3%) followed by the Euro-Mediterranean (10.7%) and West-Mediterranean (10.7%) typical for Mediterranean semi-arid climate. 2 endemic species were present and rarity reached 9% combined of rare (4%) and quite rare (5%). Among the taxa analyzed, 8 are included in the International Union for Conservation of Nature red list with different status and 2 are on the Algerian list of protected non-cultivated species.

Thermal energy performance of compressed earth building in two different cities in Moroccan semi-arid climate

The assessment of the thermal energy performance of earth-based buildings with respect to the semi-arid Mediterranean climate of Morocco is scarce, even if the country is historically known for its earthen dwellings. According to this need, this work aims to understand and evaluate the indoor thermal comfort and energy performances of passive building in two different locations. We have used EnergyPlus modeling tool and in addition, the monitored ten-day indoor temperatures in two different thermal zones in the test prototype to justify the empirical validation of Building Energy Model. The findings demonstrate, the use of compressed earth blocks coupled with passive design strategies provides better comfort and great sustainability. Thus, the summer discomfort hours are reduced about 12% for both cities compared to conventional building. However, the combination of semi-arid climate-responsive passive design has allowed to reach a thermal energy intensity reduction difference from 20 to 65 kWh.m−2. y−1.

Retrieving Soil Moisture at the Field Scale from Sentinel-1 Data over a Semi-Arid Mediterranean Agricultural Area

In this work, superficial soil moisture is estimated from SAR data at the field scale on agricultural fields over which the relationship between the co-polarized backscattering coefficient (γ0VV) and the measured soil moisture (SSMv) is both direct and inverse. An inversion algorithm is adapted to the charateristics of the single field and applied to SAR signal differences. The differences of SAR signal are obtained from a change detection (CD) method applied on the VV band of the Sentinel-1 SAR mission. In the CD method, the variations of the total backscattered signal due to sharp changes in vegetation and soil roughness are excluded from the dataset by using a machine learning algorithm. The retrieval method is applied on a low vegetated agricultural area in Spain, characterized by a semi-arid mediterranean climate and where in situ soil moisture data are available. Good results are obtained not only over fields characterized by direct γ0VV/SSMv relationship, reaching values of correlation coefficient and RMSE up to r=0.89 and RMSE=0.042 m3/m3, but also over fields with inverse relationship, obtaining in this case values up to r=0.84 ad RMSE=0.026 m3/m3. Although the inverse relationship between the backscattering coefficient and the measured soil moisture is not yet well understood in the field of soil moisture estimation from radar data, for the present case, checking the nature of this relationship was fundamental in order to accordingly adapt the soil moisture retrieval algorithm to the dataset characteristics.

Exploring Energy Retrofitting Strategies and Their Effect on Comfort in a Vernacular Building in a Dry Mediterranean Climate

This research explores the energy behaviour of a traditional house on the Mediterranean coast of south-eastern Spain. The objective of the work is to determine the optimal passive strategies for rehabilitating a traditional house, improving its energy savings and comfort, considering the characteristics of the warm semi-arid Mediterranean climate. The main novelty of this article is that it demonstrates that the limits imposed by current regulations, based on globalised climate strategy approaches, undermine the energy efficiency capacity that passive solutions in vernacular architecture already employed. The methodology used consists of a systematised multi-objective study of various energy rehabilitation strategies. Four strategies were studied: raising the thermal insulation of enclosures, improving thermal insulation and solar control glazing with movable shading devices, increasing the size of windows and introducing the use of natural ventilation enhanced by ceiling fans. The results show that simultaneous improvement of these parameters reduces cooling and heating requirements by up to 87%, reducing the energy consumption of air conditioning systems. Indoor temperatures are also maintained within the comfort limits set by regulations for 91% of hours per year without the need for air conditioning systems. This results in a passive energy-efficient and comfortable house almost all year round. This work offers an alternative solution to the comfort standards of current Spanish regulations and demonstrates the need to adapt Fanger’s analytical method for comfort estimation. The research concludes that the comfort criteria of current energy regulations should be modified to better adapt the design criteria to the dry Mediterranean climate.

Decoupling factor, aerodynamic and canopy conductances of a hedgerow olive orchard under Mediterranean climate

The degree of coupling between canopy and atmosphere, through the decoupling factor Ω, well describes the behaviour of a crop concerning its water use and carbon dioxide exchange. Super high-density hedgerow olive orchard system is in great expansion all over the world and, since it has a complex field structure in rows of adjacent trees, investigations are necessary to assess the Ω patterns, as well as aerodynamic (ga) and canopy (gc) conductances in different water conditions. In this study, in a hedgerow olive orchard (cv. “Arbosana”) submitted to full (FI) and regulated deficit irrigation (RDI), cropped under a Mediterranean semi-arid climate (southern Italy), Ω has been determined using gc, as deduced by inverting the Penman-Monteith equation, and ga, by upscaling the wind speed measured in a close station to the canopy; the transpiration has been measured by sap flow thermal dissipation method. The results showed that this olive orchard results very well coupled to the atmosphere, in any soil water conditions; Ω is generally very low, being during daytime equal in mean to 0.021±0.003 ms-1 and 0.018±0.004 ms-1 for RDI and FI, respectively. This condition is linked to ga and gc values; in fact, canopy conductance is much smaller than the aerodynamic one in any water and climatic conditions, except when all canopy surfaces are saturated in water. In this latter case, the gc assumes the highest values due to the contribution of the part of conductance attributable to the structure of the orchard.

The effect of altitude on soil organic carbon content in semi-arid mediterranean climate

One of the most effective means in the combating climate change and desertification is soil organic carbon (SOC) management. However, land use puts a high pressure to fragile SOC pools particularly in semi-arid environments where SOC decomposition rate is high due to low soil moisture. Therefore, at higher elevations of Mediterranean Basin with cooler temperature SOC is higher than the coastal plains due to the better soil moisture contents. Agricultural pressure on highlands has increased in recent years because of the relatively low water requirement of crops. The purpose of this study is to analyze and determine the SOC dynamics in relation to the variations of soil physical and chemical characteristics from different elevations, ranging from 64 meters to 756 meters at semi-arid Mediterranean climate. SOC revealed decreases versus altitude increases that varied from 24.7 to 38.7 t ha-1 with a correlation coefficient of 0.527. The main driver of decreasing SOC by elevation is most probably displacing of fine particles from surface horizons by accelerated erosion at sloping and cultivated lands of higher altitudes. As a result, it is necessary to focus both on the plant pattern along with land management techniques for enhancing soil organic matter in agricultural production for enhancing SOC at higher elevations.

Physiological responses of three field-grown species (Ceratonia siliqua, Eucalyptus camaldulensis, and Moringa oleifera) to water deficits in a Mediterranean semi-arid climate

Reforestation of degraded drylands calls for the selection of species with the capacity to withstand water scarcity. In this current study we have assessed, the physiological responses of three field-grown species (Ceratonia siliqua, Eucalyptus camaldulensis and Moringa oleifera) to water deficits in semi-arid regions in order to suggest a potential species for rehabilitation programs. The physiological behavior of the given species was studied in three irrigation schemes: subsurface drip irrigation (applied weekly), tank irrigation (applied monthly), and unirrigated plants. In a stressed state, an assessment of relative water content (RWC), water potential (pre-dawn water potential PWP and midday water potential MWP) and stomatal conductance revealed three contrasting physiological responses. First, C. siliqua stomata remained open with a high RWC at low water potentials. Consequently, this species tolerated water deficits by decreasing its leaf water potential, primarily associated with osmotic adjustment. On the other hand, E. camaldulensis was found to be a drought-avoider species, mutated to a water-saving strategy by complete stomatal closure. Finally, for the extreme case, M. oleifera showed leaf shedding under water deficit conditions. These different physiological responses allowed these species to survive water deficits, and consequently, could be considered suitable candidates for rehabilitating degraded semi-arid areas.

Multi-environment analysis enhances genomic prediction accuracy of agronomic traits in sesame.

Introduction: Sesame is an ancient oilseed crop containing many valuable nutritional components. The demand for sesame seeds and their products has recently increased worldwide, making it necessary to enhance the development of high-yielding cultivars. One approach to enhance genetic gain in breeding programs is genomic selection. However, studies on genomic selection and genomic prediction in sesame have yet to be conducted. Methods: In this study, we performed genomic prediction for agronomic traits using the phenotypes and genotypes of a sesame diversity panel grown under Mediterranean climatic conditions over two growing seasons. We aimed to assess prediction accuracy for nine important agronomic traits in sesame using single- and multi-environment analyses. Results: In single-environment analysis, genomic best linear unbiased prediction, BayesB, BayesC, and reproducing kernel Hilbert spaces models showed no substantial differences. The average prediction accuracy of the nine traits across these models ranged from 0.39 to 0.79 for both growing seasons. In the multi-environment analysis, the marker-by-environment interaction model, which decomposed the marker effects into components shared across environments and environment-specific deviations, improved the prediction accuracies for all traits by 15%-58% compared to the single-environment model, particularly when borrowing information from other environments was made possible. Discussion: Our results showed that single-environment analysis produced moderate-to-high genomic prediction accuracy for agronomic traits in sesame. The multi-environment analysis further enhanced this accuracy by exploiting marker-by-environment interaction. We concluded that genomic prediction using multi-environmental trial data could improve efforts for breeding cultivars adapted to the semi-arid Mediterranean climate.

Application of Benfratello's method to estimate the spatio-temporal variability of the irrigation deficit in a Mediterranean semiarid climate

Abstract This work presents a novel, spatially distributed, GIS-based application of Benfratello's conceptual method (developed in the 1960s) to estimate the climatic water deficit and the irrigation deficit at the field and basin scales. Explicit analytical relationships are obtained to define the deficit uncertainty on the basis of the interannual variability of temperature and precipitation. With this model, we aim at proposing a rather simple and effective tool to deal with the complicated issues of assessing the soil water balance, determining the irrigation deficit and managing the water resources in semiarid agricultural environments, in the context of climatic, land-use and anthropogenic changes. In order to test this new application, the model was applied to estimate the irrigation deficit of the Bonifica della Capitanata consortium in the Apulia region, one of the most important agricultural districts in Southern Italy and in the whole Mediterranean area, in four different historical land-use scenarios. The first results of the application seem encouraging, as by using a limited amount of parameters we estimated an irrigation demand which is in agreement with the irrigation volumes supplied by the consortium. The different land-use cases are discussed in the light of an application of the Budyko curve.

Mapping of potential groundwater recharge sites in the Smaâla area (Central Morocco)

Groundwater recharge is the process that allows water to percolate through permeable/or fractured rocks, and to enter an aquifer. Due to the large permeability of fractures at various scales, aquifers can store large quantities of water; therefore, such aquifers could be good candidates for water exploitation. In following this research, we propose the fractal dimension (FD) as an efficient tool to analyse and quantify the density and complexity of fractures as an index to assess the potentiality of groundwater recharge. The work was carried out in the region of Smaâla, Central Morocco, characterised by semi-arid Mediterranean climate with a mean annual temperature above 26 °C, and an average annual precipitation of 302 mm. In this area, the fracture networks associated with the Hercynian orogeny, were mapped and then quantified by the FD calculated using the box-counting method. The obtained results indicated that the Smaâla area can be divided according to the fracture density into three zones: zones of low FD (≈1.3–1.4) identified as poor groundwater recharge sites, spread in the southeast part of the study area; zones of medium FD (≈1.4–1.5) identified as good to moderate groundwater recharge sites, scattered across the western and southern part of the study area; and zones of high FD (≈1.5–1.61) identified as good to excellent groundwater recharge sites, scattered to the northeast and central part of the study area. Through this study, it seems that the fractal approach can be used as a representative parameter to assess the potentiality and availability of groundwater.

Use of unripe grape wine as a tool for reducing alcohol content and improving the quality and oenological characteristics of red wines

In Mediterranean viticulture, climatic conditions are the main factors that determine grape composition and wine quality. Global warming is causing an increase in the accumulation of soluble solids in grapes, leading to early harvests that result in wines with high alcohol and low phenolic content and colour intensity. The aim of this research was to determine the effectiveness of mixing wines vinified from grapes with different maturation degrees from two consecutive vintages (2018 and 2019) in order to obtain wines with lower pH, lower alcohol content and higher phenolic compound concentration. The wine obtained after mixing wine from unripe grapes (URG) with second harvest (H2) wines significantly improved the physicochemical, chromatic and phenolic characteristics compared to the first harvest (H1) wine. On the other hand, the URGH2 wine had significantly lower alcohol content and pH and higher titratable acidity than the H2 wine. URGH2 maintained its colour intensity in both years and similar values of anthocyanin and tannin in 2018 compared to H2. All the wines were subjected to sensory analysis and the panelists were able to differentiate the wines in a triangle sensory test; the URGH2 wine was preferred in both years. These results show that the blend of unripe grape with wines from technologically mature grapes to reduce alcohol content and improve wine colour could be a useful tool for mitigating the problems caused by global warming in a warm and semiarid Mediterranean climate.