Shallow geophysical and hydrological investigations to identify groundwater contamination in Wadi Bani Malik dam area Jeddah, Saudi Arabia

The integration of geophysical techniques with hydrological investigation is frequently used for solving different geological and environmental problems including groundwater quality and exploration and seismic vulnerability assessment. In this research, the shallow geophysical techniques comprising of electrical resistivity profiling, vertical electrical sounding, and ground magnetic were used to identify the contaminated areas lying in the upstream and downstream of Almisk Lake in Jeddah. The chemical analyses of water samples collected from the wells located in the downstream and upstream areas were used to support these results as an increase in the total dissolved solids (TDS) shows a decrease in the resistivity value. The results of geophysical techniques and hydrochemical analyses show that the TDS values are significantly higher in the upstream area of dam than those of the downstream, which suggests that the contaminating source is lying in the upstream of the reservoir. Moreover, the dam was not completely successful to block the contamination because of improper base. The hydrochemical analysis and geophysical results clearly indicate that the groundwater is not suitable for drinking and irrigation purposes.

Morphometric Analysis of River Donga Watershed in Taraba State Using Remeote Sensing and Gis Techniques

As climate change infiltrate and influence every sphere of the globe, the continuous study of the drainage features and assessment of the drainage basin as a fundamental geomorphic unit in water resources development and management cannot be relegated. This work has considered the analytical description of the physical division of RDCA. The three domains of the morphometric parameters (linear, areal, and relief aspects of the basin) were considered for the analysis. Remote sensing and GIS techniques were adopted in the analysis of the data using hydrological and surface tool in ArcGIS 10.2. The acquired SRTM DEM was used to delineate the catchment area and major morphometric parameters were estimated. The results show that the basin is elongated with low leminiscate ratio. RDCA is a 7th order drainage basin, with an area of 11,355 km2, having a length of about 164 km2. Value of drainage density indicates moderate runoff potentials. Stream frequency, bifurcation ratio and constant channel maintenance indicate medium permeability and that the basin produces a flatter peak of direct runoff for a longer duration. Channel encroachment, land use and land cover change seems the cause of perennial flooding in the region than change in drainage features. This study provides scientific database for further comprehensive hydrological investigation of RDCA around which Kashimbilla dam is located.

HYDROLOGICAL PROPERTIES OF BRIBIN UNDERGROUND RIVER SYSTEM (Experience learned for Seropan River System Project)

This paper is principally aimed to express some hydrological aspects regarding to the 2006-2007time series investigation within Bribin River system. The concept of karst watershed and the Bribin System historical review is firstly presented in order to give the understandable viewpoint with reference to hydrological investigation conducted in this site. Afterwards, this paper illustrates some aspects of 2006-2007 Bribin System investigation such as site selection, equipments,measurements, and spatial-temporal results on discharge fluctuation, karst flow component ratio, and rainfall intensity. Lastly, this paper also evaluates the 2006-2007 investigation constriction and gives some recommendations related to the next Seropan River System study.