Urban water demand prediction based on climate change is always challenging for water utilities because of the uncertainty that results from a sudden rise in water demand due to stochastic patterns of climatic factors. For this purpose, a novel combined methodology including, firstly, data pre-processing techniques were employed to decompose the time series of water and climatic factors by using empirical mode decomposition and identifying the best model input via tolerance to avoid multi-collinearity. Second, the artificial neural network (ANN) model was optimised by an up-to-date slime mould algorithm (SMA-ANN) to predict the medium term of the stochastic signal of monthly urban water demand. Ten climatic factors over 16 years were used to simulate the stochastic signal of water demand. The results reveal that SMA outperforms a multi-verse optimiser and backtracking search algorithm based on error scale. The performance of the hybrid model SMA-ANN is better than ANN (stand-alone) based on the range of statistical criteria. Generally, this methodology yields accurate results with a coefficient of determination of 0.9 and a mean absolute relative error of 0.001. This study can assist local water managers to efficiently manage the present water system and plan extensions to accommodate the increasing water demand.
Troposphere height has extensive interaction with other atmospheric components; it gives a good indication of what happened inside; therefore, this work tried to investigate the heat rate effect on troposphere height, especially after the global warming intensity and increased temperature degree rate along the time; thus the study covered 13 years to understand the real behavior of troposphere. Data for this work was given from the European center for medium-range weather forecasting (ECMWF) over Baghdad city, the result showed that there is a fluctuation in troposphere height, and the difference between a higher and lower point in winter was about (120 m), and that was higher than its rate on summer which was about only (30 m), also the result denoted that the fluctuation frequency becomes lower in the late of the study period. On the other side, the study found that the coherence between temperature and troposphere height fluctuation becomes higher in summer than in winter. Still, in general, the troposphere height recorded an increasing trend over time of the study period. Keywords: Troposphere height, Temperature, Baghdad city, ECMWF, Seasonal variation.
The paper describes the technical means, methods, and results of experimental studies of the spread of ice-forming agents in the boundary layer of the atmosphere under the action of ground-based aerosol generator NAG-07M. Comparison of the data on sampling by an AVA 3-240-01S probe mounted aboard Vilga-35A aircraft with aerosol propagation calculations using a 3-D SeedDisp model shows 1. The concentration of silver iodide measured in the atmosphere was above background one to a height of 1200 m at distances of 3 to 9 km from the place of the generator installation. 2. The developed SeedDisp numerical model in general qualitatively correctly describes the distribution of silver iodide aerosols in the boundary layer and the free atmosphere under the action of ground-based aerosol generator NAG-07M. Thus, the coefficient of correlation of the measured and calculated by model values of the silver iodide particles concentration in the sub-cloud layer exceeded the value of 0.7.
Climate change became an important filed of research. It is believed that climate change may be one of the greatest threats facing the Earth's ecosystem. Recent years show increasing temperatures in various regions and/or increasing extremities in weather patterns. This research explore the trends in various weather elements over the Hillah city in central Iraq using Merra-2 data for 37 years (1980-2016). The results indicated that the most affected elements by climate change were the temperature and precipitation. Temperature trend is increasing while precipitation is slightly decreasing over the 37 years period. Other weather elements such as atmospheric pressure, relative humidity and wind showed no distinct trends and their patterns are those of arid and semi-arid regions. Low-pressure patterns and dry conditions during Summer and high-pressure patterns and wet Winter. The wind during Summer is higher than its values during Winter. The wind direction is mostly Northwesterly.
Most studies indicated that the values of atmospheric variables have changed from their general rates due to pollution or global warming etc. Hence, the research indicates the changes of direct solar radiation values over a whole century i.e. from 1900 to 2000 depending on registered data for four cities, namely (Mosul - Baghdad - Rutba - Basra. Moreover, attemptsto correlate the direct solar radiation with the temperature values have been recorded over that period. The results showed that there is a decreasing pattern of radiation quantities over time throughout the study period, where the value of direct radiation over the city of Baghdad 5550 w/m2 was recorded in the year 1900, but this ratio decreased clearly to approximately 5400 w/m2 in the year 2000, which is perhaps due to the increase of general pollution rates in the atmosphere. The results also showed that the city of Rutba recorded the highest annual rate of radiation quantities, and Baghdad with Mosul recorded the lowest radiation ratios compared to the rest of the cities, in addition to that there was a large convergence of radiation ratios between them to some extent. The results showed that there is a sharp drop in radiation ratios, specifically in the years1980and 1990. As for the extent of the relationship for solar radiation with temperature levels throughout the study period, it was found that there is an inverse relationship between them, and this confirms that the cause of high temperatures is not because of increased solar radiation, but it may rather due to other reasons such as increased greenhouse gases.
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