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Since the early 1980s, several regions of Morocco have experienced alternating series of wet and dry periods related to climate change, with significant consequences for the country’s economy. This study aims to map flood hazards by using a hydraulic modeling approach, with a specific focus on the Oued (river) Zaouiat Sidi Hamza passing through Zaouiat Sidi Hamza township belonging to the High Ziz watershed (province of Midelt, region of Drâa-Tafilalet, Morocco). Hydraulic modeling and flood simulation were carried out followed by mapping of the flood hazard. The Oued Zaouiat Sidi Hamza River can cause torrential flooding issues, particularly during periods of heavy storms, impacting agricultural land and certain buildings on both river banks. All the cultivated areas developed alongside the river are at risk of flooding. Moreover, undermining and erosion of the river’s banks lead to rising high-water levels and flooding agricultural terraces. The use of geographic information systems and hydraulic modeling tools is essential to gain a deeper understanding of this situation. Also, the mapping of lineaments and fractures in the study area, carried out by satellite image processing, helped to quantify the directional influence of these lineaments on the flow of the hydrographic network, on the orientation of the circulation of surface water, and on the storage of groundwater. According to this study, the most vulnerable areas to flooding and erosion are those that receive the most water in the basin and have steep slopes. Decision-makers can use the results to produce development plans tailored to combat these risks and raise awareness among the population concerned, improving water resource evaluation and forecasting, as well as improving agricultural production.

The current study consists of evaluating surface water pollution using an integrated approach based on pollution assessment indices and statistical approaches (principal component analysis (PCA), logistic regression (LR) analysis, and cluster analysis (CA)). Thirty-four water samples from the High Ziz basin (semi-arid area), occupied by abandoned mine sites in SE Morocco, were collected and analysed for physicochemical parameters and heavy metals (Cu, Zn, Fe, Pb, Ni, and Cd). The mean concentrations of Pb, Zn, Cu, and Fe in the water samples were 41.9 mg/L, 14.8 mg/L, 20.1 mg/L, and 8.1 mg/L, respectively. The large part of the samples is in a near neutral high metal zone based on the plot of heavy metals (Fe+Cu+Pb+Zn+Ni) versus pH. The HPI, HEI, and CI pollution indices were found to average around 586.2, 321.8, and 315.8 respectively, these show strong correlations with heavy metals. The HPI, CI, and HEI values were above 100 as critical pollution index value. These indices indicate that the surface water samples are critically polluted with respect to studied heavy metals. Therefore, the high metal content of the studied samples should be of great concern for the irrigation activity. Moreover, the water quality index (WQI) shows that 76% of the water samples are unsuitable for drinking. The CA analysis grouped 34 samples into four clusters according to the similarity proprieties observed in water quality. Furthermore, the total variance is explained by 75.7% of the water quality with four components according to PCA analysis. Based on LR analysis, the hazard area is strongly correlated with the river system near abandoned mine sites, agricultural and urban areas. The water quality in the study area is controlled by natural/geogenic processes according to the interpretation of pollution indices and statistical approaches (PCA, CA, and LR). The distribution intensity of Pb, Zn, Cu, and Fe metals in the study area's surface water constitutes an environmental concern and needs a monitoring network for sustainable water resources management.

This study aims to contribute to a better estimation of the density of fractures likely to favour the drainage of surface water in the High Ziz River (HZR) basin. The method adopted consists of the use of different airborne image processing techniques (filtering, enhancement and slope analysis) which allow a good discrimination of image discontinuities (lineaments) that can then be used for producing lineament maps. The influence of these lineaments on the underground flow is then studied. Indeed, it was possible to extract the lineament network, following the exploitation of remote sensing and an objectively completed analog analysis using the PCI Geomatica LINE module and its directional filters (Sobel directional filters by the ACP method), and to extract the hydrographic network of the HZR basin, using the ArcHydro tool. After superimposing these data, their thematic maps (of the lineament and hydrographic network) were developed. In addition, this comparison of the two hydrographic networks and lineament maps showed us very varied flow directions influenced by geological structures, particularly fracturing. The topography of the region also has a secondary impact on flows through the presence of slopes generally oriented towards the SE of the basin. The correlation of the results with the different directions of the orders of the hydrographic network allowed us to identify the potential effects of lineaments on the orientations of surface water circulation. In addition to these results, the realization of the Rose diagram indicated that the dominant trend in lineaments is N90–45N° (NE–SW).

One of the adverse impacts of climate change is drought, and the complex nature of droughts makes them one of the most important climate hazards. Drought indices are generally used as a tool for monitoring changes in meteorological, hydrological, agricultural and economic conditions. In this study, we focused on meteorological drought events in the High Ziz river Basin, central High Atlas, Morocco. The application of drought index analysis is useful for drought assessment and to consider methods of adaptation and mitigation to deal with climate change. In order to analyze drought in the study area, we used two different approaches for addressing the change in climate and particularly in precipitation, i) to assess the climate variability and change over the year, and ii) to assess the change within the year timescale (monthly, seasonally and annually) from 1971 to 2017. In first approach, precipitation data were used in a long time scale e.g. annual and more than one-year period. For this purpose, the Standardized Precipitation Index (SPI) was considered to quantify the rainfall deficit for multiple timescales. For the second approach, trend analysis (using the Mann-Kendall (M-K) test) was applied to precipitation in different time scales within the year. The results showed that the study area has no significant trend in annual rainfall, but in terms of seasonal rainfall, the magnitude of rainfall during summer revealed a positive significant trend in three stations. A significant negative and positive trend in monthly rainfall was observed only in April and August, respectively.