This study investigates the impact of climate change and land use change on water resources and food security in Jordan. The country is dominated by arid climate with limited arable land and water resources, where the per capita share of water is less than 145 m³/year. The study focused on crop production and water resources under trends of anticipated climate change and population growth in the country. Remote sensing data were used to determine land use/cover changes and rates of urbanization, which took place at the cost of the cultivable land. Recession of irrigated areas led to lesser food production and food security. Outputs from crop production and water requirements models, in addition to regression analysis, were used to estimate the projected increase in agricultural water demand under the scenarios of increased air temperature and reduced rainfall by the years 2030 and 2050. Results indicated that problems of water scarcity and food insecurity would be exacerbated by climate change and increased population growth. To move from the tragedy of the commons towards transcendence, the study emphasized the need for adaptive measures to reduce the impacts of climate change on water resources and food security. The challenge, however, would remain the development and the efficient use of new water resources as a means for future sustainable development.

This study compares saturated hydraulic conductivities ( ${\mathrm{K}}_{\mathrm{s}}$ ) of three sandy soils such as coarse, medium and fine sand. The ${\mathrm{K}}_{\mathrm{s}}$ was obtained using three different methods: empirical methods based on the grain size analysis, the relative effective porosity model (REPM), and breakthrough curve analyses based on tracer tests. Column drainage tests were performed to characterize the water retention properties of the samples, which are required in the REPM. Bench scale tracer tests with various conditions were conducted to obtain reasonable linear velocities of the samples using breakthrough curve analyses and then ${\mathrm{K}}_{\mathrm{s}}$ was estimated using Darcy’s law. For the REPM, the differences of ${\mathrm{K}}_{\mathrm{s}}$ for the coarse and fine sand soils were less than one order of magnitude; however, the difference of ${\mathrm{K}}_{\mathrm{s}}$ values between the empirical methods and the breakthrough curve analyses was larger than one order of magnitude. The comparison results suggest that the REPM can be a reliable method for estimating ${\mathrm{K}}_{\mathrm{s}}$ for soil grains, and is cost effective due to its experimental simplicity.

Polarization and depolarization current (PDC) measurements of insulation oil alone can be used for faults identification. From measurement of healthy oil conditions at different moisture levels and after faults, fault identification can be achieved by comparing the PDC pattern of an oil sample against the PDC fingerprints. Furthermore, a graph plot establishes a relationship between oil sample conductivity and moisture level as well as between oil sample's measured capacitance and moisture level. These curves can be used to evaluate the oil moisture conditions and the fault type. This paper seeks to find the PDC pattern of the biodegradable oil (Envirotemp ® FR3™) at different moisture levels and after being subjected to different types of fault: partial discharge, arcing, and overheating. The experiment was carried out in the laboratory to obtain the PDC patterns generated by the oil. Changes in the PDC pattern of biodegradable oil from its fingerprint due to the increased moisture level in the oil or because of faults that occurred to the oil sample were identified. These can help in predicting the biodegradable oil-filled transformer's condition and can give some indication of the maintenance work that should be taken on the transformer.

The threat of land degradation by salinization in Jordan has been increasing over the last decades. Therefore, information about the response of local cultivars to salinity is needed to help farmers choose the most productive cultivars for areas with salt-affected soils. A recently released durum wheat cultivar Um Qais (Triticum turgidum subsp. durum) has shown to be productive under normal conditions but to date there are no known studies on its tolerance to salinity. Two experiments were conducted to investigate the response of Um Qais cultivar to salinity. A field experiment was carried out in the Jordan Valley, which is known for its hot, dry climate during the summer and low rainfall and moderate temperature during the winter. Three water salinity levels (S): S1 (2 dS m⁻¹), S2 (4 dS m⁻¹), and S3 (8 dS m⁻¹) with three irrigation amounts (R) (control = 120% (R1), 100% (R2), and 70% (R3)) were used in the field. A greenhouse experiment was conducted using four levels of saline water (S): S1 (0.65 dS m⁻¹), S2 (4 dS m⁻¹), S3 (8 dS m⁻¹), and S4 (10 dS m⁻¹). In both experiments, the leaf area index (LAI) and canopy height were measured during three growth stages, tillering, flag leaf, and maturity. The number of grains, grain yield, and above-ground biomass were measured after harvesting while soil salinity and pH were measured every three weeks during the growing season. The results showed that the maximum reduction in yield was of the 28% in the field experiment when the average soil salinity was of 6.8 ± 1.1 (standard error) dS m⁻¹ at the middle stages of the season. Significant changes were shown in the treatments of the field experiments for maximum LAI, number of grains, and aboveground biomass, but not for plant height. For the greenhouse treatments, about 60% of the maximum grain yield was obtained when the average soil salinity was 9.94 ± 1.89 dS m⁻¹ at the middle stage. Grain yield was the most sensitive parameter to the increase in soil salinity during the season. According to the findings of both experiments, Um Qais can be cultivated in moderately saline soils.

An estimate of evapotranspiration (ET) is needed for many applications in diverse disciplines such as agriculture, hydrology, and meteorology. The objective of this study was to compare two methods for estimating daily actual ET (ETa) from six sites located in four different ecological zones within Jordan. The first method used the analytical land–atmosphere radiometer model (ALARM) and the dimensionless temperature procedure, whereas the second method used ETa calculated from the FAO-56 reference evapotranspiration. ALARM converts general remotely sensed surface temperatures to aerodynamic temperature. Standard meteorological data from weather stations were used with both methods, and the Moderate Resolution Imaging Spectroradiometer (MODIS)–based leaf area index, surface temperature, and albedo were obtained to estimate ETa, using the former method. A validation study was conducted on an alfalfa field in Jordan Valley using ALARM and the American Society of Civil Engineers’ (ASCE) method, which is very similar to FAO-56 except it uses alfalfa as a reference crop. Because this alfalfa field was irrigated and because of warm air advection, ET rates based on measurements of soil moisture change ranged from about 6 to 10 mm day−1. For this range, the root-mean-square error (RMSE) for ALARM was 0.87 mm day−1 and the coefficient of determination r 2 was 0.36, whereas the RMSE for ASCE was 1.25 mm day−1 and r 2 = 0.06. There was good agreement between minimum, maximum, and average ETa for the two methods at all sites except for Irbid, for which the minimum and, consequently, the average were different. Much of the site-to-site and temporal variability was found to be statistically significant. Reasons for this variability include soil types, vegetation cover, irrigation, and warm advection.