جعفر نشيد حميد سعيد

ABSTRACT: The key objective of this work is to investigate the impact of noise from generators on a residential area in Najaf, Iraq and to determine the optimal distance between the generator and the residential area. To achieve this objective, predictions were conducted and observations were collected at 3 downwind distances (7 m, 20 m, and 50 m) from the generator on selected dates of winter and summer (Jan 25-28 and Feb 1 and 10 and June 13-14, 2025). The observations showed that when the generators were in operation, noise levels exceeded the Iraqi standard and WHO guidelines. However, when the generators were not in use but the national grid was in operation, noise levels were below the Iraqi standards, except for maximum levels. In the absence of noise from the generators and national grids, the noise levels were below the standards. The noise generally decreased by 8 dBA when moving from 7m to 20m from the generator, and by 3 dBA when moving from 20 to 50 m. There was a negative relationship between wind speed and temperature on one hand, and noise level on the other hand, with a correlation coefficient of 0.45 to 0.65 with wind speed and 0.65 to 0.7 with air temperature. In contrast, the correlation with the relative humidity was positive (0.68). Also, a simple model was applied to analyze noise dispersion over a domain of 400m. The optimal distance estimated by both modeling and linear regression to meet the Iraq daytime standard of 60 dBA is 75 m and to meet the Iraqi nighttime standard of 50dBA is 120m. The results showed the predicted LAeq were overpredicted by 2% at 7m but underpredicted by 3% and 5% at 20m and 50m, respectively.

ABSTRACT: Urban thermal stress has become one of the most critical environmental challenges facing rapidly expanding cities, particularly in arid and semi-arid regions such as Najaf Governorate, Iraq. Accelerated urbanization, population growth, extensive impervious surfaces, and the decline of green spaces have intensified the urban heat island effect, leading to elevated air and surface temperatures and increased thermal discomfort for urban residents. Nature-Based Solutions (NBS), especially urban vegetation, represent a sustainable and environmentally friendly approach to mitigating urban thermal stress. Urban plants, including street trees, public parks, green belts, and urban gardens, play a vital role in regulating the urban microclimate through shading, evapotranspiration, reduction of solar radiation absorption, and improvement of surface thermal properties. These processes collectively contribute to lowering ambient temperatures, enhancing thermal comfort, and reducing energy demand for cooling in urban areas. This study aims to evaluate the effectiveness of urban vegetation as a nature-based solution for mitigating thermal stress in Najaf Governorate. The research focuses on analyzing the relationship between vegetation cover distribution and urban temperature patterns, considering land-use characteristics and urban morphology. Particular attention is given to the selection of plant species suitable for the local climatic conditions of Najaf, emphasizing native and drought-tolerant species that can withstand high temperatures, water scarcity, and harsh environmental conditions. The significance of this research lies in its contribution to sustainable urban planning and climate adaptation strategies in Najaf Governorate. By integrating urban vegetation into urban planning policies, cities can enhance environmental resilience, improve public health, and promote long-term ecological sustainability. The findings are expected to support decision-makers and urban planners in adopting nature-based solutions as a cost-effective and adaptive strategy to reduce thermal stress and improve the livability of cities under ongoing climate change.

Abstract. Road traffic is one of the primary sources of air pollution in urban areas and consequently causing health problems especially to those people who live close to the crowded roads. The objective of this study is to investigate the impact of traffic emission on Airport Road on the surrounding residential areas in Najaf, Iraq. To achieve this objective, a traffic survey, air quality and meteorological parameters were measured during morning times on both a weekend and a weekday at three different distances-50m, 100m and 150m from both sides (A and B) of the road. The air quality results showed that the traffic emission did not cause exceedances on the applicable standards for CO and NO2 at any of the sites during sampling period. The prediction results, using SCREEN model, showed that the maximum predicted concentrations of all three air pollutants (TVOC, CO and NO2) are under predicted for both cases (i.e., USEPA and EURO 6 emission factor) at all three distances from the road, except for NO2 at distances of 50m and 100m for both cases and the predictions of CO and NO2 using USEPA emission factor give much better results than those prediction using EURO 6 emission factor. Based on the results, the CO could be considered as the best indicator for identifying the traffic impact on surrounding residential areas.

The study cover the impact of the new project on various aspects including air quality, water quality, biodiversity, oceanography, Archaeology, soil, noise, economy, social, risk assessment and tother aspecs

Abstract: Many recent studies have highlighted the substantial health-related impacts of particle number (PMno) rather than particle mass. The aim of this study is to determine the correlation of trace gases with PMno, to identify the chemical composition of particle different sizes and to predict the NOx and PMno over Yanbu Industrial City (YIC). Trace gases (NOx, SO2, H2S, O3, CO), PMno with diameter (7nm-10μm), traffic and meteorological parameters were measured at three sampling sites in YIC. The maximum PMno (333,971 cm-3) at downwind site#1 was about 2.5 times higher than that (123,842 cm-3) at upwind site#2 and about 1.2 times higher than that (263,572 cm-3) at downwind site#3. The average PMno distribution at downwind sites consisted of one distinguishable mode (nucleation mode<20nm) whereas the upwind site had two modes (the nucleation and the accumulation modes). The correlation of PMno with NO/NOx (r>0.7) are generally stronger than with NO2 at sites#1 and 2, whereas for site #3 the correlation between PMno with NO2/NOx are better than with NO. PMno has generally either weak or poor correlation with SO2 and CO, respectively. Particle samples of different sizes (7nm-10μm) were chemically analysed using ion chromatographic (IC) for inorganic ions and inductively coupled plasma mass spectrometry (ICP-MS) for trace metals at site#3. The ionic analysis revealed that sulfate and ammonium was mainly present in particle of size < 0.38μm while nitrate and chloride was mainly present in particles of size > 0.38μm. Non-sea salt sulfate was dominant in all particle sizes compared to the marine sulfate which is minor. The total sulfate and nitrate contributed 50.3% and 24.4% of the total ionic mass respectively followed by chloride (13.3%) and ammonium (10.6%). The trace-metals analysis results indicated that Na represented more than 94% of the total mass and the contributions of the remaining metals (Al, Sr, Zn, V, Cr, Fe, etc) were about 6%. A further part of this study consisted of the coupling of the WRF/CALMET system with the CALPUFF model, which was applied to predict NOx and PMno concentrations. The WRF model was employed to generate the meteorological input data for CALMET. WRF predictions were evaluated with surface data and upper air profiles using RASS/SODAR and radiosondes. WRF tends to underestimate the surface temperature on average with biases of up to -3.4oC and also underestimates temperature profiles with average biases ranging between -2.7 and -5.2oC when compared to the RASS profiler, but with a lower bias (< -2.4oC) when compared to radiosonde profiles. The mean wind speed bias for the majority of the cases was close to the benchmark of ±0.5m/s, but the mean wind direction bias for half of the cases exceeded the benchmark of 10o. It was concluded that WRF predictions can be used for air dispersion modeling to produce reasonable outputs. NOx predictions by CALPUFF showed that the contribution of the traffic to the highest concentrations during the nighttime was up to 80%, but after sunrise the contribution from industries became higher (up to 70%). The highest predicted NOx concentration (~313μg/m3) was much lower than the national ambient standard (660μg/m3) and the community area is affected much by industries during mid-morning hours when the wind shifting from land breeze to sea breeze. The fractional bias (FB) ranged between -0.1 and 1.06 indicating that the model tends to under-predict the NOx observations. PMno predictions of two sizes (7-40nm and 7nm-10μm) were derived based on the NOx predictions. All FB values were ranged between -0.1 and 0.5. It was concluded that PMno predictions were generally better than those of the NOx due mainly to adding the background term (intercept) for the PMno predictions.

An experiment was performed for estimation of turbidity over Jeddah during Spring (March, April and May 1993). The measurements include direct. diffuse and global radiation. on clear days. The data are also incorporated ill a radiation model for estimation of different components a t'solar radiation over Jeddah, The results showed thai the turbidity and consequently the amount of aerosols in the atmosphere was maximum in April. This was accompanied by a strong south to southwest wind. The coefficient of turbidity (/f) reached (0. 9) on 6 April. a very turbid dUY . On this day. the wave length exponent ( IX) approached zero. The diurnal variation of the turbidity showed an increase started at noon and extended all afternoon The average Spring turbidity in Jedduh is (0.18). The results of the model indicate that rbe average percentage difference between the measured and the calculated direct. diffuse and global radialion are 8%. 15% and 5% respectively. The model used was successful. with an over all precision for direct and global radiation of 10% for Jeddah, This gives confidence that this model probably with some improvements. can be used for estimating global radiation over Jcddah on clear days when measurements of this parameters are not available.

استقرارية الغلاف الجوي تلعب دور مهم في انتشار الملوثات الغازية في الهواء المحيط بالقرب من سطح الارض حيث عندما يكون الغلاف الجوي مستقر يؤدي الى حبس الملوثات الغازية من الانتشار وبالتالي ترتفع تراكيز التلوث بشكل كبير بينما عندما تكون حالة الغلاف الجوي غير مستقر يؤدي الى عمليات خلط عالية وبالتالي ينخفض مستوى تركيز التلوث الغازي بالقرب ن سطح الارض

الحلقة النقاشية غطت المحاور التالية: - انواع السحب والظروف الجوية المناسبة لتكونها - أمثل على انواع السحب وماهية السحب الممطرة وكيفية تحديد ذلك عند مشاهدتها - اعطاء صور للاقمار الصناعية التي توضح نوع السحب

عقدت حلقة نقاشية بقسم علوم البيئة لمناقشة نتائج الدراسة التي أجريت لتحديد العلاقة بين التراكيز العددية للجزيئات العالقة بمختلف احجامها (قطر 7 نانومتر وحتى 10 ميكرومتر) مع عدد من الملوثات الغازية حيث تم جمع قياسات الجزيئات العالقة وكذلك الملوثات الغازية (مثل أكاسيد النيتروجين وثاني أكسيد الكبريت وكبريتيد الهيدروجين واول أكسيد الكربون والاوزن) وعناصر الارصاد الجوية في ثلاثة مواقع في احدى المدن الصناعية في الممكلة العربية السعودية وكان اثنان من هذه المواقع تقع في اتجاه الرياح السائدة والموقع الثالث عكس الاتجاه السائد وأظهرت نتائج الدراسة التالي: - هناك علاقة قوية بين الجزيئات العالقة ذات الاحجام 7 الى 200 نانومتر وغاز أكسيد النتيروجين خاصة في مواقع اتجاه الرياح بسبب أن هذا الغاز ينبعث أولاً كأول اكسيد النتيروجين قبل أن يتحول الى ثاني أكسيد النيتروجين وتضعف العلاقة عن مقارنتها بجزيئات العالقة التي يزيد قطرها عن 200نانومتر - العلاقة بين التراكيز العددية للجزيئات العالقة بمختلف احجامها وغازات ثاني أكسيد الكبريت وكبريتيد الهيدروجين ضعيفة جداً بسبب أن انبعاث هذه الغازات يعتمد بشكل كبير على نسبة الكبريت في الوقود المستخدم لدى الصناعات ووسائل النقل. - العلاقة بين التراكيز العددية للجزيئات العالقة في جميع الاحجام وغاز الاوزون عكسية بسبب التحولات الكيميائية لاكاسيد النتيروجين الى غاز الاوزون بوجود الاشعة الشمسية