EXAMINE THE PROBLEM OF RURAL WATER SUPPLY IN NIGERIA
MAN AND THE CYCLE
The hydrological cycle is one which water passes through a series of transportation and motions which and endlessly repetitive in kind and in the amount of water involved (Oyebande, 1998). According to Hitgen and Tarbucs (2002), the hydrological cycle is a gigantic world wide system powered by energy from the sun in which the atmosphere provides the vital link between the oceans.
The hydrological cycle has neither a beginning nor an end. But evaporation from the ocean is often chosen as convenient and logical starting phase.
Most of the moisture is adverted in land as vapour by air masses. The vapour condense to give precipitation (rainfall) on ocean h as completed of cycles and is ready to begin another. The one that falls o n land is disposed off in several way but ultimately the water infiltrate in the ground (soil moisture and ground water) known as infiltration, some are evaporated from the earth surface and transported or run-off into the ocean, seas or rivers. Some of the falling water are intercepted by vegetation (Hewlett, 1987).
Man also tempered with every part of the hydrological cycle. Run-off is stored behind dam; evapo-transpiration losses are reduced ground water is abstracted or is artificially recharged interception is harvested as rainwater from catchments roof and temporarily stored, while natural precipitation is artificially modified under suitable condition. Through the various uses of water man changes of circulations as well as its quality (Ayoade, 1988 and Ogebande, 1981).
It must be emphasized that the total global water quality is more or less fixed and cannot be changed by man. But man through his various activities deliberately or in deliberately modifies water storage pools and the direction and strength of the flow or linkage between men. Man has influence the hydrological cycle through water resource development projects such as the building of drain to store water, irrigation and hydroelectric power generation. Apart from these, man also engages in large-scale transfer or diversion of water through pipes from one location to another and often from one basis to another; man also influence the hydrological cycles through weather modification such as cloud seeding which induce rainfall.
Lastly man has influence the hydrological cycle through rural land u se and urbanization. (Ayoade, 1988).
In general the hydrological cycle which is the cease less movement of water by evaporation into the atmosphere by mass transportation on land and sea, by discharge or ground water to river and lakes and directly to the seas from glaciers and ice cap (Nace, 1981), is used to explain the whole process of water movement in the environment.
2.2 WATER
Water is a common resource quite abundant in nature but unfortunately not readily available to man in the form desired. Water is fundamentally important to all plants, animals and man (Ajewole, 2005).
Water is essential for life and life evolved in water, water is significant due to its unique chemical and physical properties. Water is made of two atoms of hydrogen and one of oxygen and because of the unique nature of the binding; water is a solvent for many minerals and can be exist in three states as liquid, gas (at 100oc) and as solid (at freezing temperature of below-4oc) (Nelson, et al., 2002, Mbagwu, 2000); water is the matrix of life. All biological reaction occurs in water and is the most versatile chemical formed within any metabolizing cell. (Urih, 1998).
2.3 SOURCES OF WATER
There are many sources of water. These include rain, spring, and pipe borne water, deep well, fountains and streams. These can be classified as surface water and ground water.
i. Surface Water
Surface water includes streams, rivers, oceans lakes and spring. It generally has been acceptable that surface water contains more harmful micro-organisms. Compared to other sources of water includes ground water and rainwater (Oyebode, 2005).
Rain water is relatively clean of hygienically collected. It can be regarded as safe. However, while falling rain picks up small amount of gases, irons, dust and particulate, matter from the atmosphere, the contamination of rainwater is dependent on the presence of contaminants in the atmosphere through which it travels. Atmospheric dust can add reasonable number of micro-organism, which is a normal soil in habitant (Shelton, 2005; Havele, 1996; Ogbemudiare, 2006).
When rainwater reaches the surface layer of the earth, it becomes surface water and is collected as ponds, streams, lakes and river, (Mbagwu, 2003). These collections of water dissolves and carries with it some of almost anything it touches, including that which is dumped into it by man and these constitutes impurities in water (Shelton, 2003). An apparently clean spring water or stream water may be dangerously contaminated without impediment on taste, odour or appearance (Smith, 1981).
The contamination of surface water has been associated with sewage and sewage effluents. The survey of pathogenic occurrence in the sewage system of urbanized area shows that pathogen presence in sewage and sewage effluents is the rule rather than the exception in the contamination of surface water. Treatment of sewage by sedimentation and activated sludge for example, reduces the concentration of pathogen by 1-21% (90-99% reduction) in bodies of water (Medema, et al., 1999). Steam water discharges also are major causes of rapid deterioration in surface water quality, sewage event bring an elevation of turbidity, suspended solids, organic matter and faecal contamination into drainage basin, caused by urban and agricultural run-off, discharges from stream water sewers and re-suspension of sediments.
The micro-biological quality of stream water varies widely and reflect human activities in the water shed; Geldreics (1990) found that stream water is combined sewers had more than 10-fold higher thermotolerent coliform levels (8.9 x 105-4.4. x 107/1) than separate stream water sewers (1.0 x 105 – 3.5 x 106/1).
Ohagi (1998) have shown that the systematic aspect of surface water contamination is that, in most cases the surface water are contaminated in urban or sub-urban area where the water is not consume due to the availability of other alternative source but flow to the rural area where these surface water is the key source of water supply.
Livestock are a well-known source of water borne pathogen (Craun et al., 1998) in many real cases of water borne disease outbreak, at least one representative pathogenic general including, cryptosporidium giardia, campylobacter, salmonella tersinia and escherichic coli 01H 57 are considered to be zoonotic. They are slied by infected livestock and may contaminate water source and thus may be transmitted and infects human (Medema et al., 1999).
ii. Groundwater
Groundwater sources include deep well boreholes and springs (Oyebode, 2005) well water and deep well water are not acceptable for potable water production for commercial purposes. This is because the general mode of sewage disposal is by the use of septic tanks and pit latrines in Nigeria. There are no sewer and modern sewage treatment plant. Except for a few factories, consequently, ground water is polluted to high degree by sewage dumps, pesticides from agricultural activities. Spring water as a good source of drinking water must be collected in a reservoir at the shortest possible distance from the source to prevent environment pollution (Pgment, 2000; Szewzyk, et al., 2002).