Estimating Daily Reference Evapotranspiration in a Semi-Arid Region Using Remote Sensing Data

Najmaddin, Peshawa M.; Whelan, M. J.; Balzter, Heiko

doi:10.3390/rs9080779

Cited by 32 publications

(24 citation statements)

References 48 publications

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“…The study region altitude ranges between 633 m to 1706 meters above sea level. The study area climate is hot and dry over summer and cold over winter (Najmaddin et al, 2017b). The mean annual precipitation is between 450-700 mm (Najmaddin et al, 2017a).…”

Section: Methodology 1 the Study Area And Soil Samples Locationsmentioning

confidence: 99%

Evaluating the Spatial Distribution of some Soil Geotechnical Properties Using Various Interpolation Methods (Case Study: Sulaimani Province, Iraq)

Najmaddin

Salih

Abdalla

2020

Journal of Soil Sciences and Agricultural Engineering

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Soil geotechnical parameters are important inputs for the prediction of ground suitability for construction projects. The aim of the study is the evaluation of spatial distribution of some soil geotechnical characteristics for Sulaimani governorate, northern Iraq which has a semi-arid climate. Sixty different soil specimens were taken from a distance of 2.0 meters from natural ground surface, around the Sulaimani city which are suitable for resettlement purposes. Several required laboratory experiments were performed to obtain some engineering properties of the collected soils according to ASTM standards, namely field water content, field wet density, initial void ratio (IVR), and degree of saturation (DS). Three different interpolation methods namely Inverse Distance Weighted (IDW), and Thin Plate Spline (TPS), which are deterministic interpolation methods in addition to and one geostatistical method, Ordinary Kriging (OK), were applied. Cross validation and accuracy assessment of model performance are also applied and analyzed. In general, the geostatistical method performance was compared with the deterministic methods. Ok method found to be more accurate and less biased method than the other two methods, which has lower RMSE (1.38%, 11.33%, 0.07 and 0.82 gm cm-3) and ME (-0.63%, 0.94%,-0.16 and 0.3 gm cm-3) for water content, DS, IVR and wet density respectively. According to the interpolation maps 65 to 70 % of study area is likely suitable for construction purposes compare to the other 30 to 35 %, which need some precautions for the suitability issue for construction projects. The results yielded in the reliability of the obtained soil geotechnical properties from geospatial maps, which may importantly engage to suitable engineering management application and modeling of land use.

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Section: Methodology 1 the Study Area And Soil Samples Locationsmentioning

confidence: 99%

Evaluating the Spatial Distribution of some Soil Geotechnical Properties Using Various Interpolation Methods (Case Study: Sulaimani Province, Iraq)

Najmaddin

Salih

Abdalla

2020

Journal of Soil Sciences and Agricultural Engineering

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“…Furthermore, considering that the experiment was not a closed air system, it therefore invalidated the relevance of R s . In addition, the parameter R s is dependent on duration of sunshine hours (DS) and maximum possible sunshine hours available whilst the parameter R a utilises the d r function which is the distance between the earth and the sun [19], thus providing further evidence in their exclusion in Eq 2. Therefore R n was computed as per Eq 3:…”

Section: Plos Onementioning

confidence: 99%

Moistube irrigation (MTI) discharge under variable evaporative demand

2020

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We investigated the conceptual capability of Moistube irrigation (MTI) to discharge under zero applied positive pressure and under varied climatic conditions by inducing an artificial evaporative demand (Ed) or negative pressure around Moistube tubing. This study was premised on the null hypothesis that an artificially induced Ed or negative pressure does not impact MTI discharge. Moistube tubing was enclosed in a 1 m long PVC conduit. A 20 l water reservoir placed on an electronic balance provided a continuous supply of water whilst a three-speed hot air blower facilitated the radiative factor and advection process. The procedure was conducted under varied climatic conditions with three air velocity (ua) treatments namely; 1.2 m.s-1, 2.5 m.s-1, and 3.0 m.s-1 and the experiment run times were 159 h, 134 h and 10 h, respectively. The average temperature (Tave) and relative humidity (RH) data for ua = 1.2 m.s-1 were 53°C and 7.31%, whilst for ua = 2.5 m.s-1, Tave was 56°C and RH = 7.19%, and for ua = 3.0 m.s-1, Tave was 63°C and RH = 6.16%. The experimental data was input into the four variable Penman-Monteith method to compute the evaporative demand (Ed). For each Ed, the instantaneous mass flow rate (m˙) was recorded using an electronic balance and subsequently converted to volumetric flow rates. For each of the air velocities, the respective Ed values obtained were 0.16, 0.31 and 0.36 mm.d-1. The Bowen ratios (r) were well below 1 (r < 1), which suggested a sufficient supply of moisture to evaporate. For Ed = 0.16 mm.d-1 the vapour pressure deficit (VPD) was 113.08 mbars, whilst for Ed = 0.31 mm.d-1 and for Ed = 0.36 mm.d-1 the VPD were 129.93 mbars and 150.14 mbars, respectively. The recorded discharges (q) at normalised time (t*) = 1 h for Ed = 0.16 mm.d-1 was 7.67*10−3 l.hr-1.m-1 length, whilst for Ed = 0.31 mm.d-1 q = 14.5*10−3 l.hr-1.m-1 length, and for Ed = 0.36 mm.d-1 q = 20.8*10−3 l.hr-1.m-1 length. The imposed negative pressure causes an exponential increase in Moistube™ discharge, thus disproving the null hypothesis. The higher the evaporative demand the higher the discharge. This phenomenon allows MTI to be used for deficit irrigation purposes and allows irrigators to capitalize on realistic soil matric potential irrigation scheduling approach.

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“…These sites feature deep, dramatic cliff and gorge, occasional waterfall, rocky mountain slope, and mixed oak woodland, and grassland habitat. The study area climate has a semi-arid and an average (700 to 800) mm annual rainfall, most of which falls from November to April (Najmaddin et al, 2017a). Therefore, the period from November to April is defined as a high-flow period, during which the discharge at its highest, and the period from May to October is defined as a low-flow period, during which the discharge is at its lowest for the year (Najmaddin et al, 2017b).…”

Section: Site Descriptionmentioning

confidence: 99%

Self-Purification Capacity and Sag Curve of Qalachwalan-Leseer Zab River, in Sulaimanyah Governorate/Iraq

Ahmad

Barzinji

2019

Journal of Soil Sciences and Agricultural Engineering

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Qalachwalan-Lesser Zab River receives varieties of domestic and chemical wastes from settlements, recreational and agricultural lands that located around the river. Those possibly affect the capacity of natural self-purification. Water samples have been collected from five different points between Qalachwalan to Qaladza district and sag curve were applied to analyzed water quality parameters for the periods of August 2016 to May 2017. The results showed that the dissolved oxygen values varied from 4.81 mg L -1 during August to 10.35 mg L -1 in February, biochemical oxygen demand values ranged from 1.47 mg L -1 during November to 8 mg L -1 in March along the river. The statistical analysis between predicted and measured dissolved oxygen and biochemical oxygen demand showed that the less value of root mean square errors was 1.09 mg L -1 for the month of April and the highest value was 3.92 mg L -1 for dissolved oxygen during May and the less value for biochemical oxygen demand was 0.77 mg L -1 for August and the highest value 5.08 mg L -1 for March. The predicted dissolved oxygen overestimated measured dissolved oxygen by percent bias 12.5% for April and 74.9% for May and the predicted biochemical oxygen demand overestimated measured biochemical oxygen demand as well by 23.4% for August and 98.9 % for February. The purification factor varied from 0.03 to 4.45 for all over the periods. The results, indicating that the river was temporarily polluted and has a poor capacity for self-purify particularly during April that the average factor was 0.14.

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Estimating Daily Reference Evapotranspiration in a Semi-Arid Region Using Remote Sensing Data

Cited by 32 publications

References 48 publications

Evaluating the Spatial Distribution of some Soil Geotechnical Properties Using Various Interpolation Methods (Case Study: Sulaimani Province, Iraq)

Evaluating the Spatial Distribution of some Soil Geotechnical Properties Using Various Interpolation Methods (Case Study: Sulaimani Province, Iraq)

Moistube irrigation (MTI) discharge under variable evaporative demand

Self-Purification Capacity and Sag Curve of Qalachwalan-Leseer Zab River, in Sulaimanyah Governorate/Iraq

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