This research aimed to prepare for spatial hydrological modeling using the Hydrologic Modeling System (HEC-HMS) by integrating different spatial technologies to study the Beht catchment area, which covers 4560 km2 and also has a perimeter of 414 km. Firstly, the approach was to extract...

This work focused on the collection and preparation of the data required for the hydrological modelling of the Beht catchment area, which covers an area of 4560 km² with a perimeter of 414 km, by combining the various spatial technologies, in particular geographical information systems (GIS), remote sensing, and digital terrain models (DTM), with hydrological models in order to prepare for spatial hydrological modelling used for flood forecasting. The methodology consists, at first, in the automatic extraction of the sub-basins and the drainage network. Then, edit these data using the HEC-GEO-HMS extension, and the preparation of the land use and land cover data for the elaboration of a Curve Number (CN) map of Beht watershed, then the import of the basin model into the Hydrologic Modeling System (HEC-HMS) to simulate the surface runoff using six extreme daily time series events.

The catchment area of Oued Larbaâ is located in the eastern prerif at the very eastern end of the large Innaouene basin, a stream of Oued Sebou (Lahrach. A et al, 1994)[1]. The objective of the study is to establish a quality comparison of the watershed during the dry and wet seasons. Eight...

This study presents a comprehensive analysis of hydrological alterations and environmental flow components in the Beht River basin in northwest Morocco, using a coupled approach involving the Soil and Water Assessment Tool (SWAT) for hydrological modeling, the Indicators of Hydrologic Alteration (IHA) for flow regime assessment, and the Standardized Precipitation Index (SPI) for drought characterization. The SWAT model, run on a daily time step, showed satisfactory performance in terms of statistical criteria for both calibration and validation periods, despite encountering limitations, and proved its ability to simulate and reproduce the hydrological behavior of the basin. Using the IHA, we investigated changes in the hydrological regime over two distinct periods, revealing significant hydrological alteration. The SPI analysis supported these findings by highlighting the variable impacts of dry and wet periods on the hydrological regime, thus validating the observed changes in river flow indicators. As a preliminary step toward establishing environmental flows in the Beht River, this study provides foundational insights into the temporal evolution of its hydrology. These findings offer a valuable basis for better water resource management and conservation in the region.

The hydrological cycle and local climate of a region are directly impacted by climate change. Rapid fluctuations in climate alter weather patterns, resulting in the occurrence of extreme weather phenomena. This study examines two basins situated in distinct regions of Morocco, each influenced by specific climatic conditions. The primary aim of this study is to examine the climatic changes occurring within the two watersheds. Initially, it involves a comparative analysis of annual precipitation and temperatures from 1982 to 2022. Subsequently, the study projects precipitation and temperatures for the period spanning from 2024 to 2100. This analysis relies on data collected from 13 stations, 8 in the Souss-Massa and 5 in the Ouergha regions, using the Statistical Downscaling Model (SDSM) version 4.2.9. The investigation employs the fourth generation coupled global climate model CanESM2. Precipitation data and historical temperature models are used to forecast future temperatures and precipitation, based on Representative Concentration Pathway (RCP) scenarios 4.5 and 8.5. The projected scenarios indicate a decrease in observed precipitation for the years 2040, 2060, and 2080, while temperatures are predicted to rise in both watersheds across all future scenarios.

Understanding and analyzing low river flows are some of key tasks of effective water management, particularly in Chile’s Mediterranean regions, where irregular rainfall distribution leads to drought and water scarcity. This study aims to assess low-flow trends in the four major Chilean river basins (Maipo, Rapel, Maule, and Biobío) by calculating three key hydrological indices: the mean annual minimum and maximum flows (MAM), the base flow index (BFI), and the standardized precipitation index (SPI), using data from 18 hydrometric stations. The indicators of hydrologic alteration (IHA) tool was applied to calculate the MAM and BFI to assess flow variability and groundwater contributions. The SPI was calculated to examine hydrological drought conditions and evaluate how these conditions affect river flow behavior, correlating reduced low river flows with precipitation trends at the beginning of the dry season. Statistical analysis was conducted through the ordinary least squares (OLS) test for normally distributed data, and non-parametric tests, including the Mann–Kendall test, as well as Sen’s slope estimation, for data not meeting normality requirements. The results, presented both analytically and graphically, reveal trends in river flow indices and variations across the river basins, identifying critical areas of reduced flow that may require enhanced water management strategies.