Papers by ناصر سليمان ناصر العمرى
Geostatistical analysis using GIS for mapping groundwater quality: case study in the recharge area of Wadi Usfan, western Saudi Arabia
Arabian Journal of Geosciences, 2013
ABSTRACT The scarcity of water is one of the main issues in Saudi Arabia. In particular, the extr... more ABSTRACT The scarcity of water is one of the main issues in Saudi Arabia. In particular, the extreme climate in the form of less frequent rainfall affects the groundwater availability. Moreover, groundwater has been depleted by the increase in population. In this research, the spatial distribution of groundwater quality has been developed, and the prediction of groundwater chemical parameters has been made using geostatistical analysis in geographic information system (GIS) software. The study area is Madrakah village as the recharge area of Wadi Usfan located in the western region of Saudi Arabia. Ordinary kriging method was applied to map the spatial distribution of the groundwater chemistry. Most of the groundwater is not suitable for drinking purposes. Groundwater chemical parameters are decreasing toward the eastern part of Madrakah village. In predicting groundwater chemistry distribution maps, data transformation has been executed to reduce the skewness on most of the chemical parameters. The best semivariogram model for every parameter varies based on the root mean square error (RMSE) criterion. The groundwater chemical parameters, i.e., Na+, Mg2+, Cl−, conductivity, salinity, and total dissolved solid (TDS), have a strong spatial dependence, while, NO3 − and temperature have a moderate and weak spatial dependence, respectively.
Sustainability
The uncertainties in the time of concentration (Tc) model estimate from contrasting environments ... more The uncertainties in the time of concentration (Tc) model estimate from contrasting environments constitute a setback, as errors in Tc lead to errors in peak discharge. Analysis of such uncertainties in model prediction in arid watersheds is unavailable. This study tests the performance and variability of Tc model estimates. Further, the probability distribution that best fits observed Tc is determined. Lastly, a new Tc model is proposed, relying on data from arid watersheds. A total of 161 storm events from 19 gauged watersheds in Southwest Saudi Arabia were studied. Several indicators of model performance were applied. The Dooge model showed the best correlation, with r equal to 0.60. The Jung model exhibited the best predictive capability, with normalized Nash–Sutcliffe efficiency (NNSE) of 0.60, the lowest root mean square error (RMSE) of 4.72 h, and the least underestimation of Tc by 1%. The Kirpich model demonstrated the least overestimation of Tc by 4%. Log-normal distributio...
fig 07: Fitting an Equation to Reservoir Surface Area- Height Curve
fig 05: Dimensionless Surface Reservoir Area-Elevation Curve
fig 12: Relation between Diameter of outlet and the time of emptying the reservoir
Rating Curve of Dam outlet
fig 08: Dam Reservoir Contour Map
Flood and Sediment Hydrographs
One of the vital components in dam design is the dam outlet structure (the principle spillway). T... more One of the vital components in dam design is the dam outlet structure (the principle spillway). The current practice in the design of dams in arid zones is mainly based on design manuals developed by the US corps of engineers which apply to rivers and channels that have a continuous flow. These methods do not suit the conditions of arid zones where there is an intermittent flow due to intermittent rainfall events. A methodology has been developed in this paper for the design of dam outlets in arid zones. The methodology considers common features of the arid environment such as intermittent rainfall events, temporal variability of flow in the dam reservoir, and the shape of dam reservoir. A spreadsheet model has been developed to program the governing equations and implement the methodology. The theoretical back ground of the methodology is presented and applied on a proposed dam case study in Saudi Arabia. The corresponding performance curves of the dam outlet have been established.
fig 06: Dam Watershed Delineation Using WMS
Recent developments established deep learning as an inevitable tool to boost the performance of d... more Recent developments established deep learning as an inevitable tool to boost the performance of dense matching and stereo estimation. On the downside, learning these networks requires a substantial amount of training data to be successful. Consequently, the application of these models outside of the laboratory is far from straight forward. In this work we propose a self-supervised training procedure that allows us to adapt our network to the specific (imaging) characteristics of the dataset at hand, without the requirement of external ground truth data. We instead generate interim training data by running our intermediate network on the whole dataset, followed by conservative outlier filtering. Bootstrapped from a pre-trained version of our hybrid CNN-CRF model, we alternate the generation of training data and network training. With this simple concept we are able to lift the completeness and accuracy of the pre-trained version significantly. We also show that our final model compares favorably to other popular stereo estimation algorithms on an aerial dataset.
Jeddah city is located in the flood plain of a group of wadis from the east side. In 2009, the ci... more Jeddah city is located in the flood plain of a group of wadis from the east side. In 2009, the city is exposed to a devastating flood from one of the eastern wadis, called wadi Qows. More than 100 people were died, and properties' loss exceeded more than million of dollars. The current study aims at estimating the flood hydrograph of such storm (November 2009) and to delineate, via a simulation model, the flood impact on the urban areas in Jeddah. Consequently, a hydrological model is used first to estimate the flood produced from the rain storm in November 2009, and then a diffusive wave model (which is an approximation of the two dimensional Saint Venant equations) is developed, solved with the random walk theory, and programmed to delineate the inundation areas in Jeddah and to simulate the flood propagation in the city. Both models are integrated with GIS and satellite images to visualize the water depths and the inundation areas. The presented approach could be developed further as a decision support system for decision makers and planners to study any future hazards.
In this paper, a methodology has been presented to show the combination of groundwater and transp... more In this paper, a methodology has been presented to show the combination of groundwater and transport models, satellite images and uncertainty quantification to visualize the flow pattern and the transport mechanisms for decision makers. The methodology has been applied on a wastewater lake, called Buraiman or (Almusk) lake, that has been the dumping site of Jeddah's sewage wastewater since about ten years. Various flow scenarios has been considered to match the aquifer response under the limited data collected from the literature and satellite images. The Monte-Carlo methodology together with GIS and satellite images are useful tools to account for uncertainty and limitations of the data. The envelope maps that are generated by the Monte-Carlo approach to account for uncertainty are practical tools in the process of decision support system for decision makers and planners.
This paper presents a convection-decay model for simulating the transmission of flood waves in ep... more This paper presents a convection-decay model for simulating the transmission of flood waves in ephemeral channels in arid zones. The model is formulated and solved numerically by finite difference method on spreadsheet. The model has been applied on Yiba represented catchment in Saudi Arabia. The results are fairly good. Based on the proposed model, the average flood wave speed for the short reach is 10 km/hr and the average decay factor is 0.78 (hr ). For the long reach is the average speed is 7.4 km/hr and the average 1 decay factor is 0.26 (hr ). The results are fairly good. The model is capable of simulating flood wave movement 1 in ephemeral streams.
د / د اﻟﻔﻘﻲ ﻋﻤﺮو / د ﻋﻮﻳﻌﺔ ﺣﺎﺗﻢ / اﻟﻌﻤﺮي ﻧﺎﺻﺮ اﻟﻤﻠﺨﺺ : ﻟﻘﺪ ﺗ ﻢ اﻟﺒﺤﺚ ... more د / د اﻟﻔﻘﻲ ﻋﻤﺮو / د ﻋﻮﻳﻌﺔ ﺣﺎﺗﻢ / اﻟﻌﻤﺮي ﻧﺎﺻﺮ اﻟﻤﻠﺨﺺ : ﻟﻘﺪ ﺗ ﻢ اﻟﺒﺤﺚ هﺬا ﻓﻲ ﻃﺮﻳﻘﺔ ﺗﻄﻮﻳﺮ ﺗﺠﻤﻊ ﺎت اﻟﻤﻠﻮﺛ ﺔ وﺣﺮآ ﺔ اﻟﺠﻮﻓﻴ ﺎﻩ اﻟﻤﻴ ﻧﻤﺎذج ﺑﻴﻦ ﻞ اﻟﻨﻘ ﺎت وﻣﻴﻜﺎﻧﻴﻜﻴ اﻟﺴﺮﻳﺎن ﻧﻤﻂ ﻟﺮؤﻳﺔ وذﻟﻚ اﻟﺮﻳﺒﺔ وﺗﻘﺪﻳﺮ اﻟﺼﻨﺎﻋﻴﺔ اﻷﻗﻤﺎر وﺻﻮر ﻲ ﻓ ﺔ اﻟﻮاﻗﻌ ﺤﻲ اﻟﺼ ﺮف اﻟﺼ ﺮة ﺑﺤﻴ ﻰ ﻋﻠ ﺔ اﻟﻄﺮﻳﻘ ﻖ ﺗﻄﺒﻴ ﻢ ﺗ ﺪ وﻟﻘ ﺮار اﻟﻘ ﻨﺎﻋﺔ ﻟﺼ ﺎن ﺑﺮﻳﻤ ﺔ ﻣﻨﻄﻘ ) ﺪة ﺟ -اﻟﺴ ﺔ اﻟﻌﺮﺑﻴ ﺔ اﻟﻤﻤﻠﻜ ﻌﻮدﻳﺔ ( ﻲ واﻟﺘ ﻚ اﻟﻤﺴ ﺮة ﺑﺤﻴ ﺪﻋﻰ ﺗ ﻲ واﻟﺘ ﺣﻮاﻟﻲ ﻣﻨﺬ اﻟﻤﺠﺎري ﻣﻴﺎﻩ دﻓﻦ ﻣﻜﺎن آﺎﻧﺖ 10 ﺳﻨﻮات . ﺔ ﻣﺘﻨﻮﻋ ﺎت ﻣﺨﻄﻄ ﺔ دراﺳ ﻢ ﺗ ﻦ ﻣ ﺎ ﺗﺠﻤﻴﻌﻬ ﻢ ﺗ ﺪودة ﻣﺤ ﺎت ﺑﻴﺎﻧ ﺖ ﺗﺤ ﺎﻩ ﻟﻠﻤﻴ ﺔ اﻟﺤﺎﻣﻠ اﻟﻄﺒﻘﺔ ﻓﻌﻞ رد ﻟﻤﺤﺎآﺎة ﻟﻠﺴﺮﻳﺎن اﻷﻗﻤﺎر وﺻﻮر اﻟﺴﺎﺑﻘﺔ اﻟﺪراﺳﺎت اﻟﺼﻨﺎﻋﻴﺔ . ﻧﻈ ﻊ ﻣ ﻣﻮﻧﺘﻜﺎرﻟﻮ ﻃﺮﻳﻘﺔ أﻇﻬﺮت وﻟﻘﺪ ﻢ أﻧﻬ ﻨﺎﻋﻴﺔ اﻟﺼ ﺎر اﻷﻗﻤ ﻮر وﺻ ﺔ اﻟﺠﻐﺮاﻓﻴ ﺎت اﻟﻤﻌﻠﻮﻣ ﺎ ﺔ اﻟﺮﻳﺒ ﻞ ﻟﺘﺤﻠﻴ ﺪة ﻣﻔﻴ أدوات اﻟﻤ ﻲ ﻓ ﻨﻘﺺ واﻟ ﻌ ﺎت ﻠﻮﻣ . ﺪ وﻟﻘ ﺖ أﺛﺒﺘ ﻲ اﻟﺘ ﺎآﻦ اﻷﻣ ﺢ ﺗﻮﺿ ﻲ واﻟﺘ ﺮف اﻟﻈ ﺮاﺋﻂ ﺧ ﺎﻋﺪ ﺗﺴ ﻲ واﻟﺘ ﺔ ﻋﻤﻠﻴ ﺔ ﻃﺮﻳﻘ ﻲ ه اﻟﻤﺬآﻮرة اﻟﻄﺮﻳﻘﺔ أن ﻟﻠﺘﻠﻮث ﺗﺘﻌﺮض ﺪﻋﻴﻢ ﻟﺘ ﺎم آﻨﻈ واﻟﻤﺨﻄﻄﻴ اﻟﻘﺮار ﺻﻨﺎع ﻣﻨﻪ ﻟﻴﺴﺘﻔﻴﺪ اﻟﻘﺮار ﻦ .
Water scarcity is a major problem in many countries especially in arid and semi-arid areas. The s... more Water scarcity is a major problem in many countries especially in arid and semi-arid areas. The scarcity of water is further stressed by the growing demand due to increase in economic activities and population growth in developing countries. Added to these stresses, is the uncertain climate change and its consequences on water resources, especially in Arid and Semi-arid zones. Attention has to focus on developing a strategic management plan to preserve the resource from abusing, contamination and trying to maximize the resource. Nowadays, numerous governmental organizations are seeking evaluation of the existing water resources and estimation of future water resources in the Kingdom of Saudi Arabia. This knowledge is vital for decision makers to achieve the strategic plans of the country. Hydrological records (such as time series of daily rainfall, evaporation, runoff from intermittent streams etc.) in arid and semi-arid regions have extensive periods of zero values. Traditional approaches such as moving averaging techniques (MA), autoregressive models (AR), combined autoregressive moving average models (ARMA) and autoregressive-integrated-moving average models (ARIMA) could only be used when the time series is Gaussian. However, if the time series is not Gaussian, a transformation has to be applied before these models could be used, however, such tranformation does not always work. The dry-wet days' models are available in the literature. These models are mainly formulated in a context of Markov chain theory. The formal way of application of Markov model is that, the transition probability between dry and wet days are assumed stationary. In this paper an attempt is made to address such records in arid and semi-arid regions. The use of Markov chain seems promising in arid regions. The model is conceptually simple yet mathematically sound it is capable of addressing descrite data (intermittent series). Two spreadsheet models have been developed to check the probability distribution of the rainfall data at some stations and the other model is to calculate the Markov chain parameters form the data series and generate some future values of the rainfall and checking the model performance in a global sense.
Animation of generated realizations of monthly rainfall depth at Amlog Station in KSA
ABSTRACT
Climate variability is becoming a fact; many locations in the world are suffering from either ext... more Climate variability is becoming a fact; many locations in the world are suffering from either extreme floods or extreme droughts. Nowadays engineers and scientists are exploring tools to analyze this variability and try to quantify it and include in climate models in order to improve model predictions. In this paper, a spectral density function (SDF) approach is going to be utilized to analysis annual rainfall signals in the south western part of the Kingdom of Saudi Arabia. Through the SDF approach the climate cycles has been inferred from the data. Some longest annual rainfall stations (7 stations) with records between 42 years to 50 years are analyzed. Results show multiple cyclic components with significant variances. The common cycle for the seven stations has a period of 26 years (almost quarter of a century). This cycle has the strongest impact on rainfall climate variability for almost all stations in comparison with other cycles.
fig 07: Fitting an Equation to Reservoir Surface Area- Height Curve
Uploads
Papers by ناصر سليمان ناصر العمرى