Water quality is a significant criterion in matching water demand and supply. Securing adequate freshwater quality for both human and ecological needs is thus an important aspect of integrated environmental management and sustainable development.\nAssessment of water quality can be defined as the analysis of physical, chemical and biological characteristics of water. Statistical techniques such as cluster analysis (CA), discriminant analysis (DA), factor analysis (FA) and principal components analysis (PCA) are widely used which have been discussed in this review. Another approach for water quality assessment is water quality indices which aim at giving a single value to the water quality of a source reducing great amount of parameters into a simpler expression and enabling easy interpretation of monitoring data. In this review, various water quality indices (WQI) used for assessing surface water quality are discussed. As different National and International Agencies involved in water quality assessment and pollution control defines water quality criteria for different uses of water considering different indicator parameters, so there are numerous WQI specific to any region or area. An attempt to cover statistical techniques and different water quality indices developed worldwide, their background and application area has been made here.

Strength and permeability assessment of concrete structures, such as open channels are considered to be of great importance. Aggregates make up the major part of the concrete mix. So, their effect on concrete specifications should be investigated. For this reason, this paper presents the strength and permeability results of the 28-day concrete specimens made of granite, andesite, siliceous, lime, marble and tuff aggregates. In this investigation, “Cylindrical chamber” and “Twist-off” methods were used to assess the permeability and surface strength, respectively. The obtained results illustrate that rock stone has a higher strength compared with the concrete specimens made of the aggregates of the same rock stone and there is a direct linear relationship between the compressive strength of the rock stone and concrete specimens and their surface strength obtained using the “twist-off” method. Furthermore, a significant correlation was revealed between the strength and density of the saturated surface dry aggregates on one part and the strength and the penetrated water volume into the concrete specimens on the other part. The results convey that, as the water absorption of the aggregates and the permeability of the rock decrease, the strength of the concrete specimens made of the same rock stone increases, while their permeability decreases. Furthermore, it was observed that, as the strength of the concrete specimens increases, their permeability decreases. The specimens, revealing higher strength and lower permeability were made of granite, andesite, siliceous, lime, marble and tuff aggregates, respectively.