HYDROGEOLOGY Hydrogeology (hydro- meaning water, and -geology meaning the study of the Earth) is the area of geology that deals with the distribution and movement of groundwater in the soil and rocks of the Earth's crust, (commonly in aquifers). The term geohydrology is often used interchangeably. Some make the minor distinction between a hydrologist or engineer applying themselves to geology (geohydrology), and a geologist applying themselves to hydrology (hydrogeology). Ground water is water held within the interconnected openings of saturated rock beneath the land surface. The hydrologic cycle shows that when rain falls to the ground, some water flows along the land surface to streams or lakes, some water evaporates into the atmosphere, some is taken up by plants, and some seeps into the ground. As water begins to seep into the ground, it enters a zone that contains both water and air, referred to as the unsaturated zone or vadose zone. The upper part of this zone, known as the root zone or soil zone, supports plant growth and is crisscrossed by living roots, holes left by decayed roots, and animal and worm burrows. Below lies an intermediate zone, followed by a saturated capillary fringe, which results from the attraction between water and rocks. As a result of this attraction, water clings as a film on the surface of rock particles. Water moves through the unsaturated zone into the saturated zone, where all the interconnected openings between rock particles are filled with water. It is within this saturated zone that the term "ground water" is correctly applied. Ground water is held in aquifers. Aquifer is the term given to a rock unit that will yield water in usable quantities to wells or springs. An aquifer can be visualized as a giant underground sponge which holds water and which, under certain conditions, will allow water to move through it. Depending on the type, the aquifer may contain both the saturated and unsaturated zones, or just the saturated zone. The water-bearing rocks that compose aquifers consist either of unconsolidated (soil-like) deposits or consolidated rocks. Most consolidated rocks (otherwise known as bedrock) consist of rock and mineral particles of different sizes and shapes that have been welded together by heat and pressure or chemical reaction into a rock mass. Aquifers of this type are commonly composed of one or more of the following rocks: sandstone, limestone, granite, or lava. Water flows through these rocks through fractures, gas pores, and other openings in the rock. Most unconsolidated materials consist of material derived from the disintegration of consolidated rocks. Unconsolidated deposits include, in different types of unconsolidated deposits, some or all of the following materials in varying combinations: soil-like materials, gravel, sand, silt, clay, and the fragments of shells of marine organisms. Sand dunes and gravel piles are examples of unconsolidated material. Water flows through these materials through the natural openings between particles. Saudi Geophysical Consulting will help you dealing with: Artesian Well Isotope Methods Capillary Fringe Cone of Depression Confined or Artesian Aquifer Confining Layer Consolidated Rock Discharge Drawdown Ground water Ground Water Aquifer Overwithdrawal Perched Aquifer Permeability Pores Porosity Recharge Area or Zone Salt Water Intrusion Saturated Zone Spring Subsidence Surface Water Unconfined Aquifer Unconsolidated Materials Underground Water Unsaturated Zone Watershed Water Table Water Table Well Figure 01. Below, shows how can groundwater links can be severed by human activities or provide a direct pathway for underground water to become surface water. We have the methods and visualization tools that helps dealing with problems occurring in the course of groundwater modelling. Please contact us for further details about our HYDROGEOLOGY services.