Northern Qatar Research Articles

Enhancing eggplant (Solanum melongena L.) yield and water use efficiency through optimized irrigation and nitrogen practices in open field conditions

This study evaluated the interactive effects of deficit irrigation and nitrogen application on eggplant growth and yield under water scarcity in Northern Qatar (2022–2023). Two irrigation regimes were tested: full irrigation (100 %, I2) and deficit irrigation (50 %, I1), along with three nitrogen levels: 100 kg N ha−1 (F3), 70 kg N ha−1 (F2), and 50 kg N ha−1 (F1). The six treatment combinations (I1,2 + F1,2,3.) were analyzed for vegetative growth, yield components, and overall yield. Deficit irrigation (I1) increased eggplant fruit yield by 17.86 % compared to full irrigation (I2) and improved shoot height, stem diameter, and SPAD index. Nitrogen application also significantly influenced vegetative growth, with the best results seen at 50 kg N ha−1. While average fruit weight did not differ significantly across nitrogen levels, the highest fruit yield was recorded under F1 and F2 treatments. Water use efficiency (WUE) was highest under deficit irrigation (I1) at the 70 kg N ha−1 level (I1 + F2), reaching 0.41 kg ha−1 mm−1. The lowest WUE of 0.23 kg ha−1 mm−1 was observed in I2 + F2, which also had the lowest fruit yield (24.43 t ha−1). Applying 70 kg N ha−1 during deficit irrigation (I1 + F2) produced the highest fruit yield compared to other treatments, although no significant difference was found with I1 + F1. The study highlights the importance of optimized nitrogen and irrigation management for maximizing eggplant production in water-limited environments.

Glass ornaments in the Late Islamic period: composition of glass bangles from northern Qatar

Glass ornaments in the Late Islamic period: composition of glass bangles from northern Qatar

Retrieval of suspended sediment concentration (SSC) in the Arabian Gulf water of arid region by Sentinel-2 data

Suspended sediment concentration (SSC) in water increases temperature and turbidity, limits the photosynthesis of aquatic plants, and reduces biologically available oxygen. It is important to study SSC in the coastal waters of the Arabian Gulf. Thus, this study mapped the SSC of coastal water between Al Arish and Al Ghariyah in northern Qatar using the spectral bands of the MultiSpectral Imager (MSI) of Sentinel-2 by calculating the Normalized Difference Suspended Sediment Index and Normalized Suspended Material Index. The results are studied using the Normalized Difference Turbidity Index and Modified Normalized Difference Water Index. The mapping of SSC in the water using NDSSI showed the presence of a high concentration of suspended sediments between Al Arish and Al Mafjar and a low concentration between Al Mafjar and Al Ghariyah. The mapping of NSMI showed values between 0.012 (clear water) and 0.430 (more suspended material) for the occurrence of suspended materials and supported the results of NDSSI. The study of turbidity using an NDTI image showed turbidity index values ranging from −0.44 (clear water) to 0.12 (high turbidity) and confirmed the occurrence and distribution of suspended sediments and materials in the water. The MNDWI image was able to discriminate clear water with bright pixels from silty sand and mud flats. The relationships between NDSSI, NSMI, and NDTI were correlated with in-situ measurements and studied to find suitable indices to map SSC. Regression analyses showed the strongest relationship between NSMI and NDTI (R2 = 0.95) next to NDSSI and NDTI, where NDTI had the strongest effect on NDSSI (R2 = 0.86). The satellite data results were evaluated by studying the physical parameters and spatial distribution of suspended sediments in the surface and bottom waters. In addition, the grain size distributions, mineral identification, and chemical element concentrations in the bottom sediment samples were studied.

Fossil Sirenia from the Pleistocene of Qatar: new questions about the antiquity of sea cows in the Gulf Region.

One of the largest and least documented populations of dugongs (Dugong dugon) resides in the coastal waters of the United Arab Emirates, and waters surrounding Saudi Arabia, Bahrain, and Qatar. The archaeological record of dugongs in the Gulf Region is abundant, but little is known about their fossil record in the region. Here we report an isolated sirenian rib fragment from the Futaisi Member of the Fuwayrit Formation near the town of Al Ruwais, in northern Qatar. The Fuwayrit Formation is a marine Pleistocene deposit exposed onshore in Qatar and the United Arab Emirates. Based on the correlative dating of the basal Futaisi Member with other onshore platforms, the rib fragment is approximately 125 ka. We propose that this isolated rib (likely the first rib from the right side) belongs to Dugongidae, with strong similarities to extant Dugong. We cannot, however, eliminate the possibility that it belongs to an extinct taxon, especially given its similarities with other fossil dugongid material from both Qatar and elsewhere in the world. Aside from reflecting the presence of Gulf seagrass communities in the Pleistocene, this occurrence also suggests that different (and potentially multiple) lineages of sirenians inhabited the Gulf Region in the geologic past.

Chlorophyll-a concentrations in the Arabian Gulf waters of arid region: A case study from the northern coast of Qatar

Remote sensing of spectrally active Chlorophyll-a (Chl-a) in the gulf water of an arid region is important to understand the spatial and temporal variations of phytoplankton and biomass in the water. This study characterizes the spectral absorption of Chl-a and detects and maps the Chl-a of Al Arish–Al Ghariyah coastal region of northern Qatar using the data of Hyperion of EO-1, MultiSpectral Instrument (MSI) of Sentinel-2, and Operational Land Imager (OLI) of Landsat-8 satellites. The study of image spectra of Chl-a of coastal water of the Al Ghariyah region using the Hyperion image showed spectral band absorptions near 450 and 475 nm in the blue region and around 640, 730, 760, and 830 nm in the red region. The analysis of Hyperion data using image spectra by linear spectral unmixing (LSU) method showed the occurrence of Chl-a in very shallow and shallow water. The mapping of Chl-a of the Al Arish–Al​ Ghariyah coastal region was carried out using MSI and OLI data by NDCI, 2BDA, 3BDA, and FLH violet algorithms, which showed the concentrations and distributions of the Chl-a in the region. The performance of the algorithms was studied using WorldView-3 data, which provided the R2 values of 60% and the best suitability of the NDCI algorithm and MSI data to map the concentration of Chl-a. All the results were validated using field measurements, in-situ measurements, and laboratory analyses of field samples. The measurements of Chl-a showed the occurrence of poor occurrence of Chl-a and confirmed the imagery results. The remote sensing results with physical and chemical parameters of water samples allowed us to assess Chl-a concentrations in the region. This study evaluates the sensor’s capability and applications of satellite data and algorithms to map concentrations of Chl-a in the Gulf waters of the arid region.

First volumetric records of airborne Cladosporium and Alternaria spores in the atmosphere of Al Khor (northern Qatar): a preliminary survey

Daily monitoring of airborne fungal spores was carried out for the first time in Al Khor city, Qatar, using a Hirst type 7-day recording volumetric spore trap, from May 2017 to May 2019. During the sampling period, the annual and monthly fluctuations, as well as intradiurnal variations of airborne fungal spore concentrations, were evaluated. Cladosporium, followed by Alternaria, were the spore types most abundant in the atmosphere of the city, with a strong interannual variability in the atmospheric concentrations being observed. The Annual Spore Integrals (ASIns) were 3334 and 1172 spore * day/m3 (2017–2018), and 6796 and 1538 spore * day/m3 (2018–2019) for Cladosporium and Alternaria, respectively. Total daily spore concentrations showed significantly positive correlations with mean, minimum, and maximum temperatures but significantly negative correlations with relative humidity. However, due to the scarce rainfalls’ days, we did not find a statistically significant correlations between Cladosporium and Alternaria spore concentrations and this parameter. Despite this, the spore peaks were strongly related to precipitations that occurred during the previous month. In general, no significant correlations were found with wind speed but, regarding wind direction, the higher percentage of spores were collected when wind blows from the 4th quadrant (NW). According to the intradiurnal pattern, Cladosporium fungal spores displayed their maximum daily concentration during 8:00–10:00 h in the morning, with a second peak in the afternoon, while for Alternaria, the maximum peaks were observed between 08:00 and 14:00 h. Because no consistent previous aerobiological studies exist from Qatar, the aim of this study is to define the seasonality and intradiurnal behaviour of these two airborne fungal spore and the role that, in such arid scene, the meteorological parameters play on the spore concentrations.

Multi-episodic recrystallization and isotopic resetting of early-diagenetic dolomites in near-surface settings

ABSTRACTThe lower Eocene Rus Formation in Qatar reflects carbonate deposition in a semirestricted to fully restricted marine setting on a shallow ramp. Petrographic, mineralogical, and geochemical evidence from three research cores show early diagenesis has extensively altered nearly every petrological attribute of these rocks despite not having been deeply buried. In southern Qatar, the lower Rus (Traina Mbr.) consists of fabric-retentive dolomite intervals that preserve mudstone, wackestone, and packstone textures that are interbedded with depositional gypsum beds. In northern Qatar, the same member is dominated by fabric-destructive planar-e dolomite, and evaporites are absent. In both northern and southern Qatar, the upper Rus (Al Khor Mbr.) is composed of fabric-retentive dolomite intervals as well as limestone intervals rich with Microcodium textures that display evidence of dedolomitization. Geochemical analysis reveals that the limestones have an average δ18Ocal of –10.73‰ VPDB and δ13Ccal of –7.84‰ VPDB, whereas average dolomite δ18Odol is significantly higher (–1.06‰ VPDB) but δ13Cdol values (–3.04‰ VPDB; range –10 to 0‰) overlap with δ13Ccal values. Additionally, δ13Cdol trends toward normal marine values with depth away from the calcite–dolomite contact in all three cores. Petrographic observations demonstrate that dolomite crystals are commonly included in calcite and partially to completely replaced by calcite in these intervals and suggests that dolomite formed before calcite in the Microcodium-bearing intervals. Furthermore, the dolomites are commonly cemented by gypsum in the Traina Mbr. in southern Qatar, suggesting that dolomitization may have also occurred before, or concurrent with, bedded gypsum formation and indicates that dolomitization occurred early. Early dolomites were subsequently replaced by Microcodium-bearing limestones at and immediately below paleo-exposure surfaces, and at greater depths recrystallized in mixed marine–meteoric fluids, producing a negative δ13Cdol signature that trends toward more positive values away from the limestone–dolomite contact. Lastly, the dolomites underwent another phase of recrystallization in either marine-dominated fluids or possibly a well-mixed aquifer setting, resulting in a near-0‰ δ18Odol signature but retaining the negative δ13C signature. These findings thus have implications for reconstructing the diagenetic history of carbonate rocks, as they suggest that early diagenesis of carbonates can be extremely complex, resulting in multiple stages of mineral replacement and isotopic exchange in meteoric and shallow marine fluids before significant burial. Furthermore, this study shows that dolomitization of a limestone does not necessarily prevent additional early diagenesis and multiple recrystallization events. Lastly, it emphasizes the importance of incorporating petrographic observations with geochemical data when interpreting the diagenetic history of carbonate rocks.

Agro-environmental sustainability and financial cost of reusing gasfield-produced water for agricultural irrigation

Produced water (PW) is the largest by-product generated from oil and gas extraction. Currently, half of the total PW volume is managed through environmentally-controverted and costly disposal practices. In dry regions, PW could be beneficially reused to irrigate crops reducing the overexploitation of freshwater resources. However, PW quality, and particularly its high salinity, sodicity and alkalinity, create uncertainties regarding the agro-environmental sustainability and the cost of this practice. The aim of this paper was to identify potential agro-environmentally sustainable irrigation schemes with gasfield-PW in hyper-arid Qatar and to estimate their operating costs. A soil-water model was used to simulate the irrigation of sugar beet with gasfield-PW under the climatic and soil conditions occurring in northern Qatar. Different irrigation strategies combining over-irrigation, PW blending with treated sewage effluent (TSE) and PW desalination were tested in order to protect the soil and the aquifer from salinisation and sodification. The operating costs of identified agro-environmentally sustainable scenarios were estimated through a cost analysis. In the case study, the simulations indicated that using an irrigation volume up to ∼300% of the crop water needs with a blend of two-thirds PW and one-third TSE (or desalinated PW) could preserve the soil stability, crop yield and groundwater quality. The least-cost option was to reduce the irrigation amount at a little over the crop water needs and mix PW with an equivalent volume of TSE or four equivalent volumes of desalinated PW which would cost $0.26/m3 and $0.46/m3 respectively. As traditional PW disposal practices cost between $0.06–$16.67/m3, reusing PW in irrigation is thus potentially a competitive PW management strategy for O&G firms.

Are carbonate barrier islands mobile? Insights from a mid to late‐Holocene system, Al Ruwais, northern Qatar

AbstractBarrier islands are important landforms in many coastal systems around the globe. Studies of modern barrier island systems are mostly limited to those of siliciclastic realms, where the islands are recognized as mobile features that form on transgressive coastlines and migrate landward as sea‐level rises. Barrier islands of the ‘Great Pearl Bank’ along the United Arab Emirates coast are the best‐known carbonate examples. These Holocene islands, however, are interpreted to be anchored by older deposits and immobile. The mid‐Holocene to late‐Holocene depositional system at Al Ruwais, northern Qatar, provides an example of a mobile carbonate barrier island system, perhaps more similar to siliciclastic equivalents. Sedimentological and petrographic analyses, as well as 14C‐dating of shells and biogenic remains from vibracored sediments and surface deposits, show that after 7000 years ago a barrier system with a narrow back‐barrier lagoon formed along what is now an exposed coastal zone, while, contemporaneously, a laterally‐extensive coral reef was forming immediately offshore. After 1400 years ago the barrier system was forced to step ca 3 km seaward in response to a sea‐level fall of less than 2 m, where it re‐established itself directly on the mid‐Holocene reef. Since that time, the barrier has retreated landward as much as 1000 m to its current position, exposing previously‐deposited back‐barrier lagoonal sediment at the open‐coast shoreline. In modern neritic warm‐water carbonate settings mobile barrier island systems are rare. Their construction and migration may be inhibited by reef formation, early cementation, and the relative inefficiency of sourcing beach sediments from open carbonate shelves. Carbonate barrier island systems likely formed more commonly during geological periods when ramps and unrimmed shelves predominated and in calcite seas, when meteoric cementation was minimized as a result of initial calcitic allochem mineralogy. As with their siliciclastic analogues, however, recognition of the influence of these transient landforms in the rock record is challenging.

Qatar’s Wind Energy Potential with Associated Financial and Environmental Benefits for the Natural Gas Industry

This study analyzes the possibility to use the wind’s kinetic energy to produce electricity in Northern Qatar for the natural gas processing industry. An evaluation of the wind potentiality is performed based on a thorough analysis of parameters such as wind speed and direction, temperature, atmospheric pressure, and air density. In addition, based on the measured parameters, a commercial wind turbine is selected, and a case study is presented in order to quantify the energy that a wind farm could produce and its environmental benefits. Furthermore, an economical assessment is made to quantify the repercussions that it could produce if this wind farm substitutes a fraction of the energy demand (within the oil and gas field) that is currently generated by traditional hydrocarbons. The results indicate that the environmental parameters, led by a 5.06 m/s wind speed mean, allow the production of wind energy in the area with an annual CO2 savings of 6.813 tons in a 17 MW wind power plant. This enables Qatar to reduce its internal oil and gas consumption. As a result, the amount of hydrocarbon (natural gas) saved could be used for exportation purposes, generating a positive outcome for the economy with a cost savings of about 3.32 million US$ per year through such a small size wind power plant. From the energy production point of view, the natural parameters enable a single wind turbine to produce an average of 6995.26 MWh of electricity. Furthermore, the wind farm utilized in the case study is capable of generating an average of 34.976 MWh in a year.

The depositional history of near-surface Qatar aquifer rocks and its impact on matrix flow and storage properties

Carbonates and evaporites of Paleogene age form the shallow-aquifer rocks mantling most of Qatar, including the Paleocene and Lower Eocene Umm er Radhuma Formation and the Lower to Middle Eocene Rus and Dammam Formations. A core-based study was carried out to improve general understanding of the stratigraphic controls on aquifer matrix properties in Qatar. A cumulative total of 377 m of 10-cm-diameter core was recovered from three boreholes in central and northern Qatar, drilled to depths of greater than 120 m. Sedimentological attributes of these rocks were investigated through core and thin-section description, X-ray diffraction-based mineralogical assessment, as well as whole-rock stable isotopic analysis and integrated with interpretation of gamma-ray logs. Stratigraphic correlation of the penetrated intervals was then undertaken using sequence stratigraphic concepts and isotope stratigraphy (δ13C trends) in the context of recently published regional paleomaps and structural studies. In the area of Qatar, the Umm er Radhuma Formation and the overlying Traina Member of the Rus Formation were deposited in marine settings of two different basins. These basins, which extended to the south and north of Qatar, respectively, are interpreted to have been separated by a topographic high, the location of which was controlled by the presence of high-angle normal faults. The southern basin was more restricted and was the site of extensive evaporite and clay-rich siliciclastic deposition during early stages of Rus Formation. Similar evaporites and fine siliciclastic deposits are not observed in time-equivalent strata of the northern basin. During subsequent deposition of the Al Khor Member of the Rus Formation, as well as the Dammam Formation, the basins appear to have been interconnected, and fine-grained siliciclastic deposits are interbedded with, but subordinate to, carbonate strata across Qatar. Most rocks recovered for this study are dolomitic, and dolomitic rocks free of other mineral phases tend to have significant porosity (20–50%) and permeability (10–1000 mD). Decreased connectivity, flow, and storage capacity are caused by (1) the presence of gypsum beds and nodules (only southern Qatar, upper Umm er Radhuma Formation, and Rus Formation), (2) the presence of pore-occluding clays (typically palygorskite) to varying degrees in all formations, and (3) the occurrence of diagenetic calcites, most commonly in the Dammam Formation. Aquifer quality of the near-surface rocks of Qatar is in large part a function of their depositional history and is to a degree predictable using reconstruction of basin architecture, as well as sequence stratigraphic concepts.

Groundwater dynamics in fossil fractured carbonate aquifers in Eastern Arabian Peninsula: A preliminary investigation

Eastern Arabian Peninsula represents the main natural groundwater discharge area of the Arabian platform fossil aquifer system. In such settings, connections between aquifers could strongly affect the flow dynamics, water quality and availability as well as karst formation and landscape evolution. Geological structures such as folds and faults are central to aquifer connectivity, yet their role on groundwater flow is poorly understood. Herein, we perform mapping of exposed and buried structural features in the Qatar Peninsula using Landsat, Sentinel-2 and ALOS-PalSAR scenes, correlated with field, GPR and isotopic data to assess their role in aquifer connections and groundwater dynamics. Our results suggest that ENE-WSW oriented fold-related faults act as vertical conduits along which artesian upward leakages from the deep Aruma aquifer take place into the shallower main aquifer unit (i.e. Umm er Radhuma and Rus) in southern Qatar Peninsula. On the other hand, downward leakage from the freshwater lens in the Dammam aquifer take place in northern Qatar Peninsula. The deep, brackish, and gaseous-rich waters ascending along faults in south Qatar Peninsula, in addition to degrading the water quality in the main aquifer unit, enhance dissolution of carbonates and evaporites leading to strong karstification that produces abundant collapse features. Our findings suggest that structure controls can add significant complexity to recharge mechanisms and groundwater dynamics in fossil aquifers. Future large-scale radar subsurface mapping will be essential to resolve the variability of the water heads in such areas and its correlation to structural discontinuities.

Hydrogeochemical Evaluation of Groundwater in Parts of Shamal, Northern Qatar

Hydrogeochemical analyses of groundwater samples in Shamal area were undertaken to assess the groundwater chemistry of the area and hence determine its suitability for irrigation and other purposes. Thirteen groundwater samples were freshly collected from different functional wells in the area and were analyzed for different physico-chemical parameters. The analyzed parameters include TDS, EC, major cations and anions. The water quality study shows that EC ranges from 7891.88-20 736.84 μS/cm, TDS values range from 5050.80-13 271.58 mg/l. Analytical study of water samples shows that sodium varies from 1316.38-3432.39 mg/l, calcium varies from 300.81-799.93 mg/l, magnesium varies from 126.66-381.81 mg/l, potassium varies from 74-181.02 mg/l, chloride values range from 2177.75-6058 mg/l, sulphate values range from 743.87-2448.79 mg/l and bicarbonate values range from 23.13-240.3 mg/l. The high concentrations of sodium and chloride ions are indicators of saline water intrusion. The analyses of the hydrogeochemical ratios were also done to highlight the groundwater genesis and origin of mineralization. The water samples were analyzed for suitability for irrigation using various classification criteria and mathematical formula. The results from analysis of KR, SAR, SSP, PS, EC and %Na all indicate that the water in the area is unfit for use in irrigation.

Disinfection by-products of chlorine dioxide (chlorite, chlorate, and trihalomethanes): Occurrence in drinking water in Qatar

The occurrence of chlorine dioxide (ClO2) disinfection by-products (DBPs) in drinking water, namely, chlorite, chlorate, and trihalomethanes (THMs), was investigated. Two-hundred-ninety-four drinking water samples were collected from seven desalination plants (DPs), four reservoirs (R), and eight mosques (M) distributed within various locations in southern and northern Qatar. The ClO2 concentration levels ranged from 0.38 to <0.02 mg L−1, with mean values of 0.17, 0.12, and 0.04 mg L−1 for the DPs, Rs, and Ms, respectively. The chlorite levels varied from 13 μg L−1 to 440 μg L−1, with median values varying from 13 to 230 μg L−1, 77–320 μg L−1, and 85–440 μg L−1 for the DPs, Rs, and Ms, respectively. The chlorate levels varied from 11 μg L−1 to 280 μg L−1, with mean values varying from 36 to 280 μg L−1, 11–200 μg L−1, and 11–150 μg L−1 in the DPs, Rs, and Ms, respectively. The average concentration of THMs was 5 μg L−1, and the maximum value reached 77 μg L−1 However, all of the DBP concentrations fell within the range of the regulatory limits set by GSO 149/2009, the World Health Organization (WHO), and Kahramaa (KM).

Determination of 137Cs activity in soil from Qatar using high-resolution gamma-ray spectrometry

With interest in establishing baseline concentrations of 137Cs in soil from the Qatarian peninsula, we focus on determination of the activity concentrations in 129 soil samples collected across the State of Qatar prior to the 2011 Fukushima Dai-ichi nuclear power plant accident. As such, the data provides the basis of a reference map for the detection of releases of this fission product. The activity concentrations were measured via high-resolution gamma-ray spectrometry using a hyper-pure germanium detector enclosed in a copper-lined passive lead shield that was situated in a low-background environment. The activity concentrations ranged from 0.21 to 15.41Bq/kg, with a median value of 1Bq/kg, the greatest activity concentration being observed in a sample obtained from northern Qatar. Although it cannot be confirmed, it is expected that this contamination is mainly due to releases from the Chernobyl accident of 26 April 1986, there being a lack of data from Qatar before the accident. The values are typically within but are sometimes lower than the range indicated by data from other countries in the region. The lower values than those of others is suggested to be due to variation in soil characteristics as well as metrological factors at the time of deposition.

Coastal Zone Habitat-Use by Birds in Qatar: Insights from a Rapid Assessment Method During Spring Migration

In the western part of the Arabian/Persian Gulf, coastal habitats such as intertidal wetlands and mangroves are scarce and poorly studied. We conducted a rapid assessment survey of bird species richness and abundance at the Fuwairit khor lagoon in northern Qatar, using a line transect count scheme to collect data from six different generic habitat types, repeated during five consecutive days in late April 2013. To further analyze the ecological requirements of the surveyed bird assemblage per habitat type, we assigned ecological guild categories to each species and distinguished among migrants, local, and regional breeders. Mangrove and intertidal mudflats hosted the highest bird densities and the most distinctive assemblages, while the beach habitat had high concentrations of birds but relatively few species. In contrast to the wetland habitats, near-shore marine areas and dune habitats had very limited numbers of birds and a relatively depauperate species assemblage. Employing a habitat perspective in a quantitative bird survey method shows that birds are effective biodiversity indicators for a rapid survey of coastal features in a poorly-studied region of the Arabian/Persian Gulf.

Between rocks and a hard place: prehistoric funerary practices at Wādī Ḍebayʿān, northern Qatar

Archaeological survey by the Qatar National Historic Environment Record Project (QNHER) in 2009, led to the discovery of a Neolithic flint scatter, a settlement and an ancient, raised shoreline associated with higher, mid‐Holocene sea levels at Wādī Ḍebayʿān, north‐western Qatar (Al‐Naimi et al. 2010, 2011; Cuttler, Tetlow &amp; Al‐Naimi 2011). The QNHER project is a collaboration between Qatar Museums and the University of Birmingham, which over the past five years has developed a national geospatial database for the recording of archaeological sites and historic monuments in Qatar. A significant aspect of the project involved archaeological survey and excavation in advance of major construction projects. Between 2012 and 2014 excavations at Wādī Ḍebayʿān revealed a burial of a typology previously unknown in Qatar, the unmarked graves (Cuttler, Al‐Naimi &amp; Tetlow 2013).

First report of false smut disease caused by Graphiola phoenicis on date palm trees in Qatar

Date palm (Phoenix dactylifera) is the most important fruit tree in the state of Qatar and is widely planted in rural areas. In urban areas it is a common ornamental and shade plant, grown in parks and gardens and alongside roads. During spring and summer of 2001 and 2002, several date palm trees located in Al Ka'ban area (northern Qatar) showed symptoms typical of false smut disease. The fungus results in subepidermal spots on both sides of the pinnae (leaflets) and on the rachis, with small, black sori developing in abundance on old fronds. Once the spores have disseminated, only the rough black craters of the sori remain. More severe infections and damage were observed in areas of higher humidity, especially in Al Mashrub, located in the northeast coastal strip. Severe infection reduces tree growth and date production through premature death of leaves. The sori were 1-3 mm in diameter, occurred on both sides of the pinnae and were typically more abundant in the apical regions. These superficially resembled a scale insect or mealy bug infestation, but closer examination revealed the exudation of powdery yellow spores on whitish filaments. Spores were spherical to ellipsoidal, 3-6 μm in diameter and had a thick, smooth hyaline wall. The fungus was identified as Graphiola phoenicis (Djerbi, 1983), commonly known as false smut disease. It is also known as graphiola leaf spot and palm leaf pustule. Disease attacks were most common on 7- to 10-year-old palm trees and most evident on the older fronds. The disease has now spread to date palm groves throughout the country, but more quickly where trees are planted at higher densities (4-5 m spacing). False smut disease is now affecting individual date palm trees in the north, central and south areas of Qatar. False smut disease has previously been recorded on P. dactylifera in India, Egypt and Brazil (CAB International, 2003), Libya (Edongali, 1996) and Kenya (Kung'u & Boa, 1997). This is the first report of Graphiola phoenicis occurring on date palm trees in Qatar.

Determination of aquifer properties in northern Qatar for application to artificial recharge

Abstract The aquifer system in Qatar has been heavily exploited for agricultural purposes for over 20 years, leading to a decline in groundwater quality. In 1992 the Ministry of Municipal Affairs and Agriculture appointed Entec to carry out a two-year study into the feasibility of using artificial recharge to restore the aquifer system. This study involved field testing and modelling of the Rus and Umm Er Radhuma (UER) aquifers at four sites. Step, constant rate and tracer injection/reabstraction tests were carried out on each aquifer at each site. The step tests on boreholes in the UER indicated that non-Darcian behaviour occurred in the aquifer and extended a significant distance from the pumping boreholes. This was not observed during the step tests on boreholes in the Rus. A variety of techniques were used to analyse data from the constant rate tests and these provided a range of values for standard aquifer parameters as well as allowing a conceptual model of flow processes in the aquifer to be developed. This understanding was used in developing finite difference solute transport models to replicate the results from the tracer tests. Values of dispersivity of 0.5–5 m were derived for the Rus aquifer whilst values in the range 10–150 m were derived for the UER. Effective porosities were high at around 0.2 for both aquifers.

Lithostratigraphy and framework of sedimentation of the subsurface Paleogene succession in northern Qatar, Arabian Gulf

Lithostratigraphy and framework of sedimentation of the subsurface Paleogene succession in northern Qatar, Arabian Gulf