Ahmed Khalfan Al-Mayahi

Sultan Qaboos University | SQU · Department of Soils, Water and Agricultural Engineering

Accurate estimation of effective saturated hydraulic conductivity (Ksat) of a vadose zone with an underlying shallow perched aquifer is challenging. Standard pumping tests and double‐ring infiltrometers are unsuitable for this purpose. Therefore, a bailout test (BOT) was conducted in nine soil pits to evaluate the hydraulic properties of the vadose...

Purpose. Sulfur amendment plays an important role in the rehabilitation of saline and alkaline soils. Notably, the oxidation of elemental sulfur (S 0) is primarily controlled by microbial activity. The influence of S 0 amendments on its microbially-mediated oxidation in calcareous agricultural soils was investigated. Methods. Five different soils w...

Soil salinity threatens agricultural sustainability globally and is a significant challenge in Oman. Previous studies in Oman focused on examining the causality and spatiotemporal variation of groundwater and soil salinity, neglecting farmers' perceptions and attitudes toward salinity management. Therefore, this study evaluates (i) perceptions and...

This study aimed at investigating aircraft noise exposure levels, their annoyance, and potential health effects among communities living within airport catchment areas during the COVID-19 pandemic. Both field measurements and an online survey approach were used to investigate aircraft noise exposure levels, annoyance, and general health effects amo...

Recharge dams represent one of few engineering techniques to harvest flashfloods water in arid zones for augmenting the limited water resources. Formation of a low-permeable cake by deposition of suspended particles transported by ephemeral floods is a common problem for dams in arid regions (e.g. Oman, Saudi Arabia, Iran, and Tunisia). Accumulatio...

A shallow water table (SWT) rises up to several centimeters below the soil surface and even exfiltrates making surface impoundments that are common in humid climates. Recently, SWTs emerged even in arid and semi-arid regions of several metropolitan areas of the Arabian Gulf Cooperation Council (GCC) countries with a pernicious impact on the urban i...

Rises of the water table up to several centimeters below the ground surface and even exfiltration of groundwater into surface depressions are common in humid climates. Recently, a shallow water table (SWT) has emerged in several cities of the arid to semi-arid region of the Arabian Gulf Cooperation Council (GCC) countries that threatens the urban i...

Waterlogging of urban area soil in a hyperarid climate, caused by impedance of evapotranspiration due to land cover by an impervious pavement, is studied by a multidisciplinary team of researchers (hydropedeologists, hydrogeologists, groundwater engineers, soil physicists and mathematical modelers). In this paper, a study unique for an arid/hyperar...

Middle East and North African (MENA) countries over the decades are experiencing rapid industrial and infrastructural growth combined with being the global hub of oil and gas industries. These economic transformations are associated with release of air pollutants including urban air toxics (UAT) through industrial, traffic, and constructional activ...

Surface water impoundment in an unlined triangular ditch during a single managed aquifer recharge (MAR) infiltration pulse lasts for time Te, after which all initially disposed water seeps into a homogenous isotropic coarse soil. In ditches with initial water W0 with depth H0 and length L, the dyad (W0,H0) vanishes at t→Te. The ditch slope that min...

This study aimed at investigating aircraft noise exposure levels, their annoyance, and potential health effects among communities living within airport catchment areas during the COVID-19 pandemic. Both field measurements and an online survey approach were used to investigate aircraft noise exposure levels, annoyance, and general health effects amo...

Smart Capillary Barrier (SCB) has been recently promoted to decrease soil salinity and improve water use efficiency and the sustainability of arid land agriculture. In this study, we investigated the effect of SCB on soil microbial diversity, enumeration, and respiration in a tomato field trial. SCB soil and control (unstructured homogenous soils,...

Road traffic noise exposures have been recognized as serious environmental health concerns, especially in most developing countries with arid climate conditions, rapid increase in vehicle population and limited traffic management systems. The excessive noise exposure level is associated with increase in the incidence of cardiovascular diseases and...

Siltation of reservoir beds of recharge dams in arid climates seriously diminishes dams' storage capacity, lessens infiltration and deep percolation rates, increases water loss via evaporation, and ultimately lowers the recharge efficiency to the underlying unconfined aquifer. This study explores possibilities for enhancing the infiltration rate of...

The number and production capacities of greenhouse farms have been increased across the globe, driven by an effort for addressing food security problems related to the rapid population growth and the effects of climate change. As a result, there was a large increase in the number of greenhouse farm workers who are typically involved in chemical pre...

New water-conserving irrigation technologies are vital in arid countries. We investigated the effects of (i) soil substrates made of Smart Capillary Barrier Wick (SCB-W), consisting of silt loam blocks surrounded by sand-sheathes and irrigated with a sand wick cylinder (WC) as compared to a control (homogenous soil irrigated by the same wick system...

An isosceles triangle in a vertical cross-section of a trench is considered as a boundary from which free water in the trench seeps into a porous bed. A finite, initially impounded water volume vanishes from the channel and soil moisture moves in conjugation with surface water in a transient 2-D saturated-unsaturated regime. If capillarity is ignor...

An isosceles triangle in a vertical cross-section of a trench is considered as a boundary from which free water in the trench seeps into a porous bed. A finite, initially impounded water volume vanishes from the channel and soil moisture moves in conjugation with surface water in a transient 2-D saturated-unsaturated regime. If capillarity is ignor...

This study assessed the perception of urban residents of A'Seeb city, Oman, about the impact of their activities on environment. A sociological survey using questionnaire was used to know the residents' perceptions about urban gardening, municipal-waste disposal, and soil and water contamination. Viable pathogenic bacteria, water soluble metals, ba...

Omani home-gardens are jeopardized by the poor agronomic practices and unqualified gardeners. This study aimed to find: (i) gardening characteristics, practices and gardener’s perception to irrigation water management, soil preparation-fertility, (ii) determinants of use of water saving methods (WSM), and (iii) reasons for garden adoption. A questi...

Groundwater recharge dams represent one of few practical engineering techniques to augment the limited water resources. Formation of a low-permeable cake by deposition of suspended particles transported by ephemeral flashfloods is a common problem for dams in arid regions (e.g., Oman). The Al-Khoud dam, Oman, is considered in this study (Ebrahim et...

The accelerated rate of urbanization is affecting the soils that are fundamental ecological assets for cities and land-use planning. The use of urban soils for gardening and landscaping is very famous all over the world owing to its numerous benefits. This study was planned to investigate the impacts of different human activities on the characteris...