Search Results (2)

The potential of inland valleys to enhance food security and improve agricultural resilience to climate change in Africa is constrained by a limited understanding of their hydrological functioning and inadequate water management. In order to synthesize knowledge on hydrological responses in inland valley areas, this work reviewed 275 studies from tropical Sub-Saharan Africa (SSA). Data from the literature search were collected from Scopus™, ScienceDirect™, Web of Science™, Google Scholar™, and doctoral theses repositories such as ZEF, HAL, and Theses.fr, covering studies published from the inception of these databases through 31 May 2023. Our approach involved, firstly, a bibliometric analysis of all papers to gain insights into research trends and interests. Secondly, we performed a quantitative synthesis of results from 66 studies examining stream flows in a set of 79 inland valleys to better understand factors that govern runoff dynamics in these environments. Correlative analyses and clustering methods were applied to identify potential links between runoff and watershed physical parameters. The findings highlight the varied responses of inland valleys over both time and space, influenced by a combination of catchment drivers. The correlation matrices between hydrological indices and physical parameters indicate a strong relationship among runoff and a range of parameters, of which the most significant are rainfall (R² = 0.77) and soil silt content (R² = 0.68). Challenges in accurately spatializing information related to potential determining components of the water cycle, such as groundwater dynamics and soil moisture, seem to have limited the exploration of interactions between river flow, soil moisture, and groundwater. Future works should prioritize the development of accurate and user-friendly hydrological models that balance complexity and data availability to enhance the understanding of inland valley behavior at fine scales and consolidate food security in Africa. Full article

This work compares the applicability of several free-surface evaporation and runoff equations in simulating water level variations of small Mediterranean wetlands. The Amarga and Jarales wetland are two pilot sites with an evaporite-karst genesis located in southern Spain. The water level was continuously recorded in both wetlands, and exhaustive weather monitoring was performed. The combined datasets have permitted quantification of the surficial elements of their water budget (precipitation, runoff, and evaporation). Several campaigns of groundwater level measurements were also done to characterize the direction of groundwater flows. The morphometrical analysis of the Jarales wetland was accurately performed based on a LiDAR dataset. A total of 225 limnimetric simulations of the Jarales (90) and Amarga (135) wetlands were performed, combining different evaporation and runoff equations. During the study period, the curve number method, coupled with the Penman equation, reached the Jarales wetland’s best calibrations. The Vardavas–Fountoulakis modification of the Penman model fit better with the Amarga wetland record. The obtained results permit specification of the water budget of both wetlands during several years and confirm that the groundwater–surface water relationship affects the wetland hydric dynamic to different degrees. Nonetheless, the limnimetric models were calibrated for a short period, including dry years, making it necessary to extend the control period longer and validate the models under different hydroclimatic conditions. Finally, the differences between wetland functioning are explained in a conceptual hydrological model that can be useful for wetland conservation and management of related aquatic ecosystems. The understanding of the origin and fate of water in wetlands permits assessment of how future scenarios would affect hydric functioning and suggests adequate conservation measurements. Full article