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Dayat Roumi Lake, a vast body of permanent and shallow water in Morocco, is exposed to urban, tourist, and agricultural constraints. This human intervention can lead to microbial pollution of the lake ecosystem, hence the need to assess this contamination. For this reason, we undertook in this study an evaluation of the microbiological quality of the lake's water. Thus, seasonal water samples were taken at eight selected stations, taking into account the reception sites of the tributaries and anthropic activities. The parameters determined were: temperature (T), pH, dissolved oxygen (DO), electrical conductivity (EC), biological oxygen demand (BOD), chemical oxygen demand (COD), ammonium (NH4+), nitrates (NO3-), orthophosphates (OP), total phosphate (TP), total coliforms (TC), fecal coliforms (FC) and fecal streptococci (FS). The results reveal: - A high water conductivity exceeding the admissible value recommended by the Moroccan standard. - A significant presence of coliforms and fecal streptococci, in dry periods, exceeding the standards set by the WHO, which could be attributed to a summer temperature favorable to the development of coliforms. This fecal contamination leads to an increased consumption of dissolved oxygen (high BOD and low DO values) explaining the fish mortality in this period of the year. - The principal component analysis identified the sources of water quality degradation as domestic sewage, agricultural run-off, domestic waste, and human and animal excreta. - The hierarchical analysis divided the sampling stations into three different clusters. The results of the MQI classified the waters from not to highly polluted. Station 4 was classified as the most polluted site. The results of the DOC/BOD ratio showed a spatial and temporal heterogeneity of the biodegradability of the oxidizable matter present in the lake waters. For all these reasons, an effective management plan must be established to protect this water body from further pollution.

Humanity’s water needs are constantly increasing, however, under the action of humanity themselves, the reserves of this substance are, constantly, deteriorating in quantity and quality. It is, therefore, necessary to preserve the water reserves. However, any development of a hydrosystem’s quality conservation strategy is based on determining the chemical characteristics of its waters. Therefore, the objective of this study is to investigate the spatial and temporal variations of water quality in the Tiflet River, a watercourse in the northwest of Morocco, to estimate its degree of pollution and to determine its main sources of pollution. Thus, eight stations, distributed along the watercourse and positioned taking into account the potential sources of pollution, were fixed, and eleven physicochemical parameters were, seasonally, evaluated. Multivariate statistical techniques were used to assess variations in water quality and identify the main factors responsible for pollution. The results showed that wastewater discharges into the river can increase the water salinity, phosphorus load and organic pollution load of the river. The total loads of nitrogen and nitrate pollution were higher compared to the standard norms in the stations exposed to agricultural pollution and to the leaching of the watersheds, which could aggravate the eutrophication state of the river and stimulate the growth of aquatic vegetation. The organic pollution load recorded in the wet season is low, compared to that recorded in the dry season. Whereas, the nutrient load recorded during the dry season is low, compared to that recorded in the wet season. An overall pollution index was used, classifying surface waters from sub-clean to moderately polluted.

Groundwater is one of the most important natural resources that is overexploited and extensively polluted by human activity. Furthermore, drinking this dirty water might have major consequences for human health. Before using groundwater, it is consequently required to conduct a precise and regular assessment of its quality. Furthermore, for five monitoring stations in the Khemisset-Tiflet region, cluster analysis (CA), principal component analysis (PCA), and a fuzzy logic technique were utilized to analyze water quality. The CA classified the sample sites into three categories. The PCA identified temporal characteristics of water quality status. Group I include stations characterized by high temperature and low DO, COD, and BOD5 values. Group II includes stations characterized by high values of pH and low concentrations of NO3 -, Cl-, SO4 2- and turbidity. Group III includes stations characterized by high concentrations of NO3 -, Cl-, SO4 2- and turbidity and low concentrations of pH. In addition, fuzzy logic to reveal more information about groundwater quality. In effect, water quality in spring and winter was the best; the parameters responsible for the deterioration of water quality are NO3 -, Cl-, SO4 2- and turbidity. [ABSTRACT FROM AUTHOR]

As in many countries worldwide, deterioration of quality of water in Morocco's natural reserves continues, such that an inventory of qualities of these reserves has become necessary. Based on statistical analyses of the data collected by measuring nineteen physicochemical variables, and applying an index, the comprehensive pollution index, to those data, the quality of the waters of Lake Dayat Roumi, Morocco, were assessed. Waters of the lake are currently characterized by a salinity of 921.7 mg Cl−/L and 124.2 mg sulfates/L. The concentration of chloride exceeds the value indicated in the standard norms. This can affect the composition of the sediment, overlying water, and specific composition of biota in the lake. Status and trends of values of other parameters also indicate deterioration of water quality in this lake. Multivariate statistical analysis made it possible to differentiate four clusters of samples according to their physicochemical characteristics. These groups are due to inputs from three sources of materials: leaching of rocks from the watershed and plantations, discharge of domestic wastewater and runoff water. Samples taken from deeper parts of the lake indicate a depression of concentrations of dissolved oxygen during the hot season. The analysis results demonstrate the heterogeneous degradation of the water quality in the peripheral areas and deep parts of the lake, favored by the leaching of soils by rainwater, which, when sufficiently severe, can cause repeated mortalities of fishes. This situation requires regular water quality monitoring to develop a management plan for restoration of water quality in the lake to preserve valued ecological services. [ABSTRACT FROM AUTHOR]