Hydrologie : recherche actuelle

This research investigated the influence of the local geology on the groundwater potential of the two kunike chiefdoms (Sanda and Barina) in the Tonkolili District, Northern Sierra Leone. The local geology is made up of rocks typical of the West African Archean greenstone belt. The stratigraphic sequence is marked by the basic ultramafics followed by mafics (metavolcanics) and a metasedimentary unit i.e., quartzite and banded iron formations in a greenstone belt lying on or beside granitic basement rocks. The basement relationship of the granites to the supracrustals has been obliterated by intrusion of Late-Kinematic granites and by deformation and metamorphism during the Liberian tectonothermal event (=2700 Ma) which produced the dominant N-S to NNE-SSW trend. Because of the geology, aquifers in the studied area are located in two different lithologies-granitic terrain and schist belt. Aquifer characteristics such as transmissivity and yield were measured and compared for the different lithologies. Comparison results show that the yield is greater (0.03%) in the granitic terrain than in the schist belt. And this is because of the presence of clays in the schist belt. The research also revealed that groundwater is readily available in the area.

Study was conducted on the physico-chemical water properties of Zobe reservor Dutsinma, Katsina State Nigeria. Water samples were collected from four different sample stations i.e., Makera, Badole, Garhi and Bagaggadi respectively, for the period of one year (May 2015 to April 2016). Samples for Conductivity, pH, Dissolved Oxygen (DO), Temperature, Alkalinity, Turbidity, Hardness, Chloride, and Nitrate were collected during the morning hours, between 7:00 am to 9:00 am. The result showed variations in the monthly mean values of all the water quality parameters tested. The water is too turbid most especially during the beginning of raining season, despite this variation some of the values were within the tolerable range of the majority of tropical fresh water fish species. But the water cannot be used for domestic use unless it undergoes intensive treatment.

The current paper emphasizes on the study of the water resources of Iraq. Iraq is facing a dire water crisis due to the decrease in the quantities and degradation in the qualities of the water reaching its borders with the two rivers Tigris and Euphrates. The Euphrates and Tigris rivers provide more than 98% of Iraq’s water demands for the various purposes. Degradation of these rivers has become a serious problem. Analysis of the previous studies is made and the available data are collected. Most of the studies reached an important conclusion, Iraq face serious water shortage problem. Analysis and Expectation of the population size, study of the existing agricultural use and expansion of the cultivated land are presented. The consumption of water withdrawals for the three purposes Agricultural, municipal, and industrial use are analyzed and presented in the paper. In addition, the Expectations of the share per capita are made for the Future until 2100, depending on the expectations of population size and amount of water supply. The water power is studied and suggestions for the new plant are made. Furthermore, some of the discharged fresh water to the Arabian Gulf represents a loss of fresh water. Suggestion to save this loss by constructing a new dam to separate between the fresh and salt water upstream Basra city is suggested. Some of the collected data is included in the paper.

Similitude theory adapted to archaeological system analysis provides insight into thought processes underlying agricultural field-system designs used by Andean societies. A basic equation governing the optimum rate of food production dependent upon land, water, labor and technology resources is derived and compared to Chimu, Tiwanaku and Inka field-system designs. Actual designs are close to theoretical optimum designs demonstrating advanced engineering used in decision making underlying field-system designs. Further examples demonstrate how Andean societies managed land, water, labor and technology to provide economic advantage for their populations. The presentation illustrates that agricultural field-system designs were based upon scientific/economic principles and provide a further dimension as to how Andean societies successfully sustained their agricultural development.

Land-Surface Models (LSMs) exhibit large spread and uncertainties in the way they partition precipitation into surface runoff, drainage, transpiration and bare soil evaporation. To explore to what extent water isotope measurements could help evaluate the simulation of the soil water budget in LSMs, water stable isotopes have been implemented in the ORCHIDEE (ORganizing Carbon and Hydrology In Dynamic EcosystEms: the land-surface model) LSM. This article presents this implementation and the evaluation of simulations both in a stand-alone mode and coupled with an atmospheric general circulation model. ORCHIDEE simulates reasonably well the isotopic composition of soil, stem and leaf water compared to local observations at ten measurement sites. When coupled to LMDZ (Laboratoire de Météorologie Dynamique-Zoom: the atmospheric model), it simulates well the isotopic composition of precipitation and river water compared to global observations. Sensitivity tests to LSM (Land-Surface Model) parameters are performed to identify processes whose representation by LSMs could be better evaluated using water isotopic measurements. We find that measured vertical variations in soil water isotopes could help evaluate the representation of infiltration pathways by multi-layer soil models. Measured water isotopes in rivers could help calibrate the partitioning of total runoff into surface runoff and drainage and the residence time scales in underground reservoirs. Finally, co-located isotope measurements in precipitation, vapor and soil water could help estimate the partitioning of infiltrating precipitation into bare soil evaporation.