Nearly 90% of farming households in Senegal rely on rainfed agriculture; in recent years, climate change-induced disruptions to rainfall patterns and the ensuing depletion of water resources have had adverse effects on agricultural production, livelihoods, and food security. Recent studies recommend further assessment of the viability of and potential for Flood Residual Water Cultivation (FRWC) as an alternative growing strategy (i.e., to supplement or extend natural growing seasons). This study utilizes satellite imagery, GIS mapping, and crop analysis to identify areas with high potential for FRWC in Senegal's Sédhiou and Tambacounda regions, and recommends key crops that can be grown using FRWC and support food security. By calculating the Normalized Difference Water Index (NDWI) values based on historical data for the rainy season (September) and the first dry month after the rainy season (November) over a 9-year period, areas with flooding potential were identified and mapped. To assess the crop-growing potential for these mapped areas, we used crop reference evapotranspiration (ET) and determined daily water requirements for the select crops included in our analyses. indicated suitable FRWC areas along river valleys in both regions, with specific locations identified along the Gambia River, the Senegal River in the Bakel Department, and low-lying plains near Kidira and Gourel Bouri. It was observed that regions closer to the Sahara Desert required more water for crop production due to higher temperatures and evapotranspiration rates. Our study identified a total potential FRWC area of 20.7 km² and recommends short-duration crops like okra, French beans, and drought-tolerant crops such as sorghum for FRWC. The integration of FRWC with climate-smart management practices can aid in climate adaptation and economic empowerment in the studied regions, and in Sub-Saharan Africa at large.

Cold-water corals (CWCs) are considered vulnerable to environmental changes. However, previous studies have focused on adult CWCs and mainly investigated the short-term effects of single stressors. So far, the effects of environmental changes on different CWC life stages are unknown, both for single and multiple stressors and over long time periods. Therefore, we conducted a six-month aquarium experiment with three life stages of Car- yophyllia huinayensis to study their physiological response (survival, somatic growth, calcification and respira- tion) to the interactive effects of aragonite saturation (0.8 and 2.5), temperature (11 and 15 ◦C) and food availability (8 and 87 μg C L−1). The response clearly differed between life stages and measured traits. Elevated temperature and reduced feeding had the greatest effects, pushing the corals to their physiological limits. Highest mortality was observed in adult corals, while calcification rates decreased the most in juveniles. We observed a three-month delay in response, presumably because energy reserves declined, suggesting that short-term ex- periments overestimate coral resilience. Elevated summer temperatures and reduced food supply are likely to have the greatest impact on live CWCs in the future, leading to reduced coral growth and population shifts due to delayed juvenile maturation and high adult mortality.

The paper proposes a probabilistic approach to the assessment of the impacts of multipurpose dams. It is framed around the notion of Nature’s Contributions to People (NCP) in the setting of the Water-Energy-Food nexus. The socio-ecological context of the Tana River Basin in Kenya and the construction of two multipurpose dams are used to highlight co-produced positive and negative NCP under alternative river regimes. These regimes produce both damaging floods that ought to be controlled and beneficial floods that ought to be allowed. But the river regime that results from hydropower generation and flood risk reduction may not be the one that is most conducive to food and feed-based NCP. The approach relates the economic value of river-based NCP coproduction to the probability of flooding to derive the expected annual value of NCP and a NCP value-probability curve. The relation between NCP flows and flood characteristics is tested and estimated based on regression analyses with historical data. Results indicate that the net economic value of key NCP associated with multipurpose dams for local people and associated social equity effects largely depend on the frequency of flood events and on the way impacts are distributed across communities, economic sectors and time.

Adverse stress, such as the long-term restriction of food intake and activity in intensive production, leads to a depression-like mental state in sows. Mood disorder, such as depression, is a widely concerned animal welfare issue. However, little is known about the biological mechanisms that underlie mood disorders in pigs. This study is the first attempt to establish a pig depression model by acute stress. A total of 16 adult Bama pigs were divided into the control and model groups, with 8 pigs (half male and half female) per group. The pigs in the model group were restrained for 24 h in a dark and ventilated environment, with food and water deprivation. After the restraint, behavioral tests (feed intake, sucrose preference test, open field test, and novel object test) were used to evaluate apparent indicators. The levels of COR and ACTH in the serum and the levels of 5-HT, NE, and BDNF in the hippocampus and medial prefrontal cortex were detected using ELISA to identify the physiological state. After acute stress, pigs exhibited decreased feed intake and sucrose preference, increased serum COR levels, decreased hippocampal 5-HT levels, and exhibited more fear. Finally, the model was evaluated according to the weight of the test indicators. The overall score of the model was 0.57, indicating that modeling was feasible. Although the reliability and stability require further verification, this novel model revealed typical depression-like changes in behavior and provided a potential method to establish a model of depression in pigs.

Traditional rice (<i>Oryza sativa</i> L.) management (tillage and flooding) is unsustainable due to soil degradation and the large amount of irrigation water used, an issue which is exacerbated in the Mediterranean region. Therefore, there is a need to explore rice management strategies in order to improve water-use efficiency and ensure its sustainability. Thus, field experiments were conducted to determine the medium-term effects of different irrigation and tillage methods combined with a single compost application on water and rice productivity, as well as food safety in a semiarid Mediterranean region. The management systems evaluated were: sprinkler irrigation in combination with no-tillage (SNT), sprinkler irrigation in combination with conventional tillage (ST), which were implemented in 2015, and flooding irrigation in combination with conventional tillage (FT), and their homologues (SNT-C, ST-C, and FT-C) with single compost application in 2015. In reference to rice grain yield, the highest values were observed under ST treatment with 10 307 and 11 625 kg ha⁻¹ in 2018 and 2019 respectively; whereas between FT and SNT there were no significant differences, with 8 140 kg ha⁻¹ as mean value through the study. Nevertheless, sprinkler irrigation allowed saving 55% of the total amount of water applied in reference to flooding irrigation. Furthermore, the highest arsenic concentration in grains was found under FT but it decreased with compost application (FT-C) and especially with sprinkler irrigation, regardless of tillage management systems. However, sprinkler irrigation favors the cadmium uptake by plants, although this process was reduced under SNT in reference to ST, and especially under amended compost treatments. Therefore, our results suggested that a combination of sprinkler irrigation and compost application, regardless of the tillage system, could be an excellent strategy for rice management for the Mediterranean environment in terms of water and crop productivity as well as food safety.

The paper proposes a probabilistic approach to the assessment of the impacts of multipurpose dams. It is framed around the notion of Nature’s Contributions to People (NCP) in the setting of the Water-Energy-Food nexus. The socio-ecological context of the Tana River Basin in Kenya and the construction of two multipurpose dams are used to highlight co-produced positive and negative NCP under alternative river regimes. These regimes produce both damaging floods that ought to be controlled and beneficial floods that ought to be allowed. But the river regime that results from hydropower generation and flood risk reduction may not be the one that is most conducive to food and feed-based NCP. The approach relates the economic value of river-based NCP coproduction to the probability of flooding to derive the expected annual value of NCP and a NCP value-probability curve. The relation between NCP flows and flood characteristics is tested and estimated based on regression analyses with historical data. Results indicate that the net economic value of key NCP associated with multipurpose dams for local people and associated social equity effects largely depend on the frequency of flood events and on the way impacts are distributed across communities, economic sectors and time.

In this study, apricot-pit-based activated carbon was functionalized and used as a sorbent for the preconcentration of lead (Pb²⁺) in different water and food samples. The activated sorbent was modified with ethylenediaminetetraacetic acid (EDTA) to enhance its selectivity for the efficient removal of Pb²⁺ ions. The modified activated sorbent was characterized using FTIR, an SEM, BET, and TGA. The column adsorption method was used to study the adsorption capacity of synthesized and modified activated carbon and analyzed using atomic absorption spectrophotometry. A multivariate procedure, i.e., Plackett–Burman design (PBD) and central composite design (CCD), was studied for optimizing the adsorption process, which allows the optimization of multiple variables at the same time. An interference study was conducted to ascertain the selectivity of the developed method. The developed method was validated by assessing certified reference materials and additional standards for Pb²⁺ detection in real samples. To assess the precision of the proposed procedure, repeatability (RSD_r) and reproducibility (RSD_R) were calculated, which were determined to be <3.0 (n = 7) and <7.5 (n = 15), respectively. The obtained results revealed that the modified AC is a suitable and efficient sorbent for the preconcentration of Pb²⁺ in real water and food samples.

Dissertation (MSc (Geoinformatics))--University of Pretoria, 2023. | The challenge of meeting the growing demands for water, energy, and food is further complicated by the impact of climate and land use and land cover (LULC) change. The Mpumalanga Province where agricultural production compete with coal mining for land and water consumption is a prime example of challenges involved in sustaining the water, food, and energy. A more holistic understanding of LULC can help in managing competing land use objectives, leading to improved climate change adaptation strategies. The Water-Energy-Food (WEF) nexus is an effort to address challenges affecting WEF sectors by taking into consideration the inter-relatedness and interdependencies between these sectors to balance their perspectives and management. As a result, this study aimed to undertake a pragmatic approach that is based on geospatial analytical methods to support WEF nexus climate change adaptation in South Africa’s Mpumalanga Province. To achieve this, the study investigated the impact of LULC change on WEF resources by analyzing South African National Land Cover (SANLC) data from 1990, 2014, 2018 and 2020 using Geographical Information Systems (GIS) and remote sensing techniques. The study also located the recently completed and ongoing adaptation projects that contribute to the WEF nexus in the study area. As such, the logistic regression model was implemented using three scenarios to understand the drivers of the location of the WEF nexus-based climate change adaptation interventions or actions spanning from environmental to socio-economic drivers. Scenario 1: Model based on environmental variables only; Scenario 2: socio-economic variables only and scenario 3: combining environmental and socio-economic variables. Based on the understanding of the drivers and spatial estimation, a framework or model was developed to synthesize and prioritize potential areas of climate change adaptation intervention or action in Mpumalanga Province. The results of LULC change over the study period (1990 – 2020) show that the LULC areas under agriculture, built-up areas, mines and quarries increased from 18.84%, 2.33%, 0.61% in 1990 to 23.73%, 3.41% and 0.79% in 2020, respectively. While grasslands have decreased from 37.36% in 1990 to 30.39% in 2020. All of these changes have a direct impact on water supplies, energy sources, and food production. It was evident that more interventions were associated with areas of extreme climatic variables (e.g., drought related). All models were statistically significant, with Area Under the Curve (AUC) = 72% for scenario 1; 67% for scenario 2 and 73% for scenario 3. The results of the spatial estimation revealed that the northeastern region and northwestern region of the Mpumalanga Province should be prioritized for adaptation interventions. This work provided a broader view of the impact of resource use and management on the overall environment and societal well-being. The results obtained from this study indicate that the use of geospatial tools can be beneficial in the planning and prioritization of activities related to climate change adaptation. | Water Research Commission (WRC) | Geography, Geoinformatics and Meteorology | MSc (Geoinformatics) | Unrestricted | Faculty of Natural and Agricultural Sciences

The European Green Deal has set climate and energy targets for 2030 and the goal of achieving net zero greenhouse gas emissions by 2050, while supporting energy independence and economic growth. Following these goals, and as expected, the transition to “green” renewable energy is growing and will be intensified, in the near future. One of the main pillars of this transition, particularly for Mediterranean countries, is solar photovoltaic (PV) power. However, this is the least land-efficient energy source, while it is also highly competitive in food production, since solar parks are often developed in former agricultural areas, thus resulting in the systematic reduction in arable lands. Therefore, in the context of PV energy planning, the protection and preservation of arable lands should be considered a key issue. The emerging technology of agrovoltaics offers a balanced solution for both agricultural and renewable energy development. The sustainable “symbiosis” of food and energy under common lands also supports the specific objective of the post-2020 Common Agricultural Policy, regarding the mitigation of and adaptation to the changing climate, as well as the highly uncertain socio-economic and geopolitical environment. The purpose of this study is twofold, i.e., (a) to identify the state of play of the technologies and energy efficiency measures of agrovoltaics, and (b) to present a comprehensive analysis of their interactions with the water–energy–food–land nexus. As a proof of concept, we consider the plain of Arta, which is a typical agricultural area of Greece, where we employ a parametric analysis to assess key features of agrovoltaic development with respect to energy vs. food production, as well as water saving, as result of reduced evapotranspiration.

The paper proposes a probabilistic approach to the assessment of the impacts of multipurpose dams. It is framed around the notion of Nature's Contributions to People (NCP) in the setting of the Water-Energy-Food nexus. The socio-ecological context of the Tana River Basin in Kenya and the construction of two multipurpose dams are used to highlight co-produced positive and negative NCP under alternative river regimes. These regimes produce both damaging floods that ought to be controlled and beneficial floods that ought to be allowed. But the river regime that results from hydropower generation and flood risk reduction may not be the one that is most conducive to food and feed-based NCP. The approach relates the economic value of river-based NCP co-production to the probability of flooding to derive the expected annual value of NCP and a NCP value-probability curve. The relation between NCP flows and flood characteristics is tested and estimated based on regression analyses with historical data. Results indicate that the net economic value of key NCP associated with multipurpose dams for local people and associated social equity effects largely depend on the frequency of flood events and on the way impacts are distributed across communities, economic sectors and time.