The presence of an economical solution to predict soil behaviour is essential for new construction areas. This paper aims to investigate the ultimate interpolation method for predicting the soil bearing capacity of An-Najaf city-Iraq based on field investigation information. Firstly, the engineering bearing capacity was calculated based on the in-site N-SPT values using dynamic loading for 464 boreholes with depths of 0–2 m, using the Meyerhof formula. The data then were classified and imported to the GIS program to apply the interpolation methods. Four deterministic and two geostatistical interpolation methods were applied to produce six bearing capacity maps. The statistical analyses were performed using two methods: the common cross-validation method by the coefficient of determination (R²) and root mean square error (RMSE), where the results showed that ordinary kriging (OK) is the ultimate method with the least RMSE and highest R². These results were confusing so, the backward elimination regression (BER) procedure was applied to gain the definite result. The results of BER show that among all the deterministic methods, the IDW is the optimal and most significant interpolation method. The result of geostatistical methods shows that EBK is the best method in our case than the OK method. BER also applied to all six methods and shows that IDW is the ultimate significant method. The results indicate no general ultimate interpolation method for all cases and datasets type; therefore, the statistical analyses must be performed for each case and dataset.

This study intends to evaluate university students’ awareness regarding water pollution in Iraq to show the environmental education contribution in reducing water pollution. The study was conducted in Wasit university, Wasit province, Iraq by field questionnaire survey with 388 students from the civil engineering department and engineering college. The questionnaires were divided according to the pollution causes into industrial, agricultural and sewage water pollutants. The data were analyzed utilizing the thematic analysis to assess environmental knowledge and awareness of water pollution risks. The results show that most students have high interest in environmental conservation, yet, a lack of education in general environmental education, as the educational curriculum focuses on theoretical aspects more than the practical ones. The results also show that the media role is inactive concerning environmental awareness of water pollution. This study provides a scientific view of policymakers for potential future conditions to find solutions that achieve sustainability goals.

Solid waste is one of the leading environmental problems affecting human lives. Selecting a landfill where waste is disposed of is a complicated issue that related to many factors and regulations. In this study, the optimal sanitary landfill site for An-Najaf city was assessed using the GIS and weight criteria method. Eight appropriate criteria were selected, which are: urban area, rivers, roads, soil types, elevation, wind, slope, and archaeological, historical and religious sites. Moreover, the weighting of the criteria by using experts’ opinion and previous similar literature. The “weighted overlay tool” is then applied to get a map of the significance index for selected landfill sites. Seven suitable sites with an area of 177,762,986 m² and form 0.62% from the total city area can accommodate the solid waste generated for a period, not less than ten years10 years.

Maintaining natural processes and supporting social and economic growth depend heavily on water supplies. However, Future climate is predicted to bring higher temperatures, which will increase evapotranspiration; lower precipitation totals; and changes in the seasonal pattern of precipitation. Iraq is more vulnerable to climate change than other nations due to the underdeveloped and fragile water management systems there, as well as the country’s desert and warmer environment and increasing sensitivity to extreme weather events. The present work aims to analyse the literature dealing with climate change’s effects on water resources in Iraq. The Scopus database was searched using the keywords (Iraq, models of climate change, and water resources). Most models study the effect of high temperatures and evaporation on water resources using different tools, the most important of which are SWAT, LARS-WG, and HEC-HM. The analysis of previous studies shows that the results of all the literature concordant that Iraq is on the verge of severe water scarcity due to high temperatures and the resulting decrease in rainfall, increase in evaporation, decrease in vegetation cover and increase in desertification.

The unified soil classification system (USCS) first proposed by Casagrande and subsequently developed by the Army Corps of Engineers. It widely used in many building codes and books. An-Najaf city is the most important city in Iraq due to its religious and spiritual value in the Muslim world, so it is fast expanding and continuous developing city in Iraq. The data from 464 boreholes in the study area for depths of 0–26 m have been used. 13 Soil samples were collected from each borehole with 13 depths level (0–26) m with 2 m intervals. The USCS was applied to the soil samples from 13 depth levels borehole. This research aims to create a geodatabase for soil properties for An-Najaf. The ArcGIS 10.5 software was used to interpolate the spatial data to produce 33 geotechnical maps for fine soil, coarse soil and USCS for 13 depth levels. For numerical soil data, Ordinary Kriging has been used for interpolation mapping of Fine and Coarse percentage data for each depth. For non-numerical (nominal) soil data (USCS class), the Indicator Kriging method is used. The results show that the coarse soil occupied 85–95% for depth 0–16 m and consist of (SP, SP-SM, SM) while fine soil occupied 5–15% consisting of (OL, CH, ML) subsequently, this soil when compacted has a permeability of pervious to semi impervious, good shearing strength, low to very low compressibility and acceptable workability as a construction material. The results also show that after 16 m depths until 26 m, the fine soil percentage increased to 40% with a coarse soil percentage of 60%, indicating changes in soil characteristics as the permeability became semi-pervious to impervious, fair shearing strength, medium compressibility and fair workability as a construction material. The study results will provide help and saving time, efforts and money in preliminary engineering designs.