Climate change poses a significant threat to agricultural productivity, particularly in regions vulnerable to extreme temperatures and water scarcity, such as Irbid, Jordan. This study assesses the future impacts of projected shifts in precipitation and temperature on wheat yields, using the Decision Support System for Agrotechnology Transfer (DSSAT) model for calibrating and validating under local agro-environmental conditions. Two shared socioeconomic pathways (SSP3-7.0 and SSP5-8.5), representing high-emission and fossil-fuel-intensive futures, were evaluated across mid- and late-century periods (2030–2060 and 2070–2100). The DSSAT model was calibrated using local field data to simulate crop phenology, biomass accumulation, and nitrogen dynamics, showing strong agreement with observed grain yield and harvest index, thereby confirming its reliability for climate impact assessments. Yield projections under each scenario were further analyzed using machine learning algorithms—random forest and gradient boosting regression—to quantify the influence of individual climate variables. The results showed that under SSP5-8.5 (2030–2060), precipitation was the dominant factor influencing yield variability, underscoring the critical role of water availability. In contrast, under SSP3-7.0 (2070–2100), rising maximum temperatures became the primary constraint, highlighting the growing risk of heat stress. Predictive accuracy was higher in precipitation-dominated scenarios (R² = 0.81) than in temperature-dominated cases (R² = 0.65–0.73), reflecting greater complexity under extreme warming. These findings emphasize the value of integrating well-calibrated crop models with climate projections and machine learning tools to support climate-resilient agricultural planning. Moreover, practical adaptation strategies, such as adjusting planting dates, using heat-tolerant varieties, and optimizing irrigation, are recommended to enhance resilience. Emerging techniques such as seed priming show promise and merit integration into future crop models. The findings support SDG 2 and SDG 13 by informing climate-resilient food production strategies.

Urban areas face challenges with water scarcity, and the use of non-conventional water resources for uses not requiring potable quality is being promoted more and more by governments and international agencies. However, non-conventional water resources, such as rainwater and greywater, need to be treated before use to avoid health risks and possible nuisance (smell, bacteria and algae proliferation in storage tanks, etc.). This study is aimed at demonstrating the feasibility of a system reusing treated greywater for toilet flushing, relying on a nature-based treatment technology—ground-based green façades—with limited maintenance requirements which is therefore easily replicable for decentralized treatment systems, like those of greywater reuse at building scales. The demonstrative system has been installed at the University of Jordan’s Al-Zahra dormitory in Amman and uses a degreaser as the primary treatment followed by ground-based green façade technology as a secondary treatment mechanism. The effluent is stored in an underground tank and directed to a tertiary treatment mechanism with UV lamps to remove pathogens before being reused for lawn irrigation and toilet flushing. Samples from influent and effluent were analyzed for various physical, chemical, and microbiological characteristics. The degreaser significantly reduced turbidity, TSS, total BOD₅, and total COD levels in greywater. When combined with the green wall façades, the system demonstrated high removal efficiencies, particularly for turbidity, TSS, total COD, and total BOD₅. The treated effluent met irrigation reuse standards for all the parameters, including total coliform and E. coli concentrations. The UV disinfection unit proved to be an effective post-treatment step, ensuring that water quality standards for reuse were met. The system’s overall performance highlights its ability to manage low- to medium-strength greywater. Results suggest the applied green wall system has significant potential for wider adoption in urban settings.

Decentralized graywater treatment using nature-based systems represents a sustainable, low-energy alternative to centralized wastewater technologies, particularly in water-scarce regions. This study evaluates the performance of a rain-garden-based constructed wetland implemented at Zain Park in Jerash, Jordan, for on-site graywater treatment and potential non-potable reuse. The system consists of two filtration beds with multi-layer gravel–sand media planted with ornamental vegetation to promote physical filtration, adsorption, and biologically mediated transformations. Influent and effluent samples were monitored monthly from April 2024 to January 2025 and analyzed for biodegradable and oxidizable organic fractions (BOD₅ and COD), nutrients (TN, PO₄³⁻), suspended solids, turbidity, salinity indicators, and microbial parameters (E. coli and total coliform). Average removal efficiencies reached 98% for BOD and 96% for COD, while turbidity and TSS were reduced by more than 96%, indicating effective organic degradation and particulate retention. Nutrient removal was moderate, with 40% reduction in Total Nitrogen and 74% in nitrate, reflecting partial nitrification–denitrification and plant uptake. Microbial removal was variable, with an average reduction of 0.8 log₁₀ (64.7%) for E. coli and 1.1 log₁₀ (82.6%) for total coliforms, indicating that passive filtration alone may not ensure complete pathogen attenuation. Post-treatment disinfection and substrate enhancements (aeration and plant selection) can strengthen system efficiency and support sustainable graywater reuse in water-stressed regions, contributing directly to SDG 6 (Clean Water and Sanitation), SDG 11 (Sustainable Cities and Communities), and SDG 12 (Responsible Consumption and Production). These findings support the applicability of compact constructed wetland systems as decentralized wastewater treatment solutions in arid and semi-arid urban environments.

River crossing bridges in low-gradient floodplains can be affected by limited conveyance, backwater control, and scour-related foundation risk. This study evaluates a proposed IL 13 bridge replacement over the Mid Fork Saline River, Illinois, using HEC-RAS 1D steady-flow modeling, hydrologic inputs from USGS StreamStats for a drainage area of 236.45 mi², bridge opening analysis, multiple-opening interpretation, and HEC-18 scour assessment. Natural, existing, and proposed conditions were compared under design floods and Ohio River tailwater scenarios. The proposed bridge increased the effective waterway opening under all evaluated hydraulic scenarios, with increases of approximately 68.5–79.5% under the no-tailwater case, 76.1–76.9% under the 10-year Ohio River tailwater case, and 71.7–72.1% under the 50-year Ohio River tailwater case. Bridge opening velocity decreased by about one-third, indicating lower local hydraulic intensity and improved conveyance through the main opening. Contraction scour was not controlling, while computed pier scour decreased by approximately 8–10% and the controlling right abutment scour decreased slightly. Because empirical HEC-18 scour equations can have large uncertainty, commonly approaching an order of a factor of two in practical scour prediction, these reductions are interpreted only as comparative trends. They do not provide a basis for reducing foundation design requirements, but they indicate that the proposed replacement does not worsen the controlling scour response. Overall, the replacement improves hydraulic compatibility, reduces local hydraulic stress, and does not worsen the governing scour response. The study supports SDG 9, SDG 11, and SDG 13 in a hydraulic-infrastructure sense by promoting resilient bridge serviceability, safer transport connectivity, and adaptation-oriented flood risk assessment; however, full life-cycle carbon, cost, and network-resilience metrics were outside the scope.

This secondary-data integrated assessment combines national wastewater treatment records, two national sludge reports, Jordanian regulatory criteria, published agronomic evidence, engineering scenarios, and a previously prepared spatial screen. The present national context includes 33 municipal wastewater treatment plants (WWTPs), but the analytical sources cover different historical plant sets. The 2020 GIZ report surveyed 29 operating WWTPs and reported sludge-quality data for 25 plants, comprising 28 plant-stage records. The 2014 USAID strategy covered 28 WWTPs, with metal data for 9 plants and six nutrient samples from 3 plants. In the GIZ records, mean concentrations were 3.44 mg Cd kg⁻¹, 7.93 mg Pb kg⁻¹, 603.79 mg Zn kg⁻¹, and 111.86 mg Cu kg⁻¹ dry solids. Maximum concentration-to-limit ratios were 1.00 for Cd, 0.103 for Pb, 0.525 for Zn, and 0.377 for Cu. USAID nutrient samples averaged 3.93% total N, 1.71% total P, and 0.71% total K. GIZ estimated 101,533–108,719 t dry solids yr⁻¹ in 2020 and 128,540–149,332 t yr⁻¹ in 2035. USAID produced lower estimates of 50,947 and 72,418 t yr⁻¹ for the same years, showing major model uncertainty. The source spatial screen mapped 10,150.28 km², including 745.62 km² of protected rangeland reserves. Excluding those reserves leaves 9404.66 km² for further regulatory and field screening. The results support controlled reuse based on batch testing, pathogen reduction, nitrogen and phosphorus budgets, and long-term soil monitoring.

The excessive use of conventional NPK fertilizers can reduce nutrient use efficiency due to nutrient losses, emphasizing the need for controlled-release fertilizer systems. This study aimed to prepare and evaluate olive pomace-derived biochar (BC) as a carrier for nitrogen–phosphorus–potassium (NPK) fertilizer and assess its effects on nutrient release and lettuce performance. Biochar was produced by pyrolysis at 400 °C and loaded with NPK fertilizer. The BC/NPK composite was characterized using Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD), nutrient-release behavior was evaluated in deionized water and soil. The cumulative nutrient release reached 64% in deionized water and 91% in soil. Under greenhouse conditions, BC/NPK applied at 100% and 75% NPK rates increased lettuce fresh weight, plant height and leaf number to 163.33 and 183.67 g, 23.00 and 23.67 cm, 34 and 36, respectively. Moreover, BC/NPK reduced nitrate accumulation in lettuce leaves, with nitrate concentrations decreasing in outer leaves to 10 and 0.73 mg g⁻¹ and in inner leaves to 2 and 1.33 mg g⁻¹ at the 100% and 75% rates, respectively. These findings demonstrate that olive pomace-derived BC/NPK is a promising slow-release fertilizer capable of improving crop performance while supporting sustainable nutrient management and agricultural waste valorization.