Water Pollution Sources
Water has a big importance in our life; it stays on the base of biosphere existence; the water is a habitat for aquatic plants; it has kinetics and potential energy useful for the human being and necessary for nature; water is the main cause of the surface relief modeling, is an agent of cooling in technique and in the nature; is the prim matter in economy; it is a way of transport for ships but and for substances dissolved; is way of hygiene for cleaning (washing); it is a therapeutically agent and so on.
On the Earth the water consists a constant quantity and we can't influence it, like other resources. The human dirties the water. If we use too much water, we damage the aquatic habitat, the nature and the environment, in general. For having desired water without affection the stable of the development , we have to know it and to understand it, because with its banal appearance the water in reality is a whole universe. The water forms on our planet a real shield for Earth, that is named the hydrosphere and it is in relation with atmosphere, lithosphere, and biosphere. The hydrosphere consists form 3 parts: the water from the atmosphere (meteoritic), the water from the surface of land (surface water) and the water belief the land (ground water).
Hydrographical network and water monitoring stations
|For hole centuries there were made big efforts to determinate it's quantity and water's reappearance. All the quantity of water from our planet is estimate for 1,4 mild km 3 .
In comparison with the rest of the Europe and Romania Republic of Moldova is a country with redoes resources of water. In spite of a lot accumulation, the volume of surface waters and the debit of the rivers are small. The density of hydrographic network is, on average, 0,48 km/km 2 , varying from 0.84 km/km 2 in the north of the country to 0.12 km/km 2 in the east part. The main sources of rivers water ensuring are rainfalls and snowmelt runoff.
The hydrographic net of Republic of Moldova is represented trough 3621 rivers and rivulets, including 7 which have the length over 100 km, and other 247 - over 70 km, 57 lakes with the surface of 62,2 km 2 and about 3000 artificial water basins. The total length of the rivers is bigger then 16000 km. The Nistru (annual debit - about 10 km 3 ) and Prut (debit - about 2,4 km 3 ) with the sections of 630 km and 695 km marks the border between the Republic of Moldova, Ukraine and Romania.
The biggest natural lakes are situated on the course of Prut (Beleu, Dracele, Rotunda, Fontan) and the river Nistru (Bîc, Ros, Nistrul Vechi). The biggest artificial accumulation reservoirs are Costesti - Stînca on the river Prut (435 mln. m 3 ) and Dubasari on the Nistru river (277,4 ml. m 3).
Water ecosystem (River Prut)
The base characteristics of the main courses and of the biggest reservoirs of water from the Republic of Moldova are shown in table 1 and 2.
An especial role in ground balance of water has the underground waters. They take active part in the hydrologic cycle like a component part of the underground water debit. In the Republic of Moldova about 40% of the population uses the underground water with hydrostatic pressure and from the first aquatic horizon (without pressure).
A source of underground water
A particular value for the republic has the waters from shallow and underground aquifers. On the Republic of Moldova territory, in conformity with the statigraphic principles it is note 17 complexes and water horizons: phreatic, Quaternary, Middle Sarmatian, Lower Sarmatian - Badenian, Cretaceous, Upper Sarmatian, Tortonian, Paleocene, Jurassic superior, Jurassic medial, Pontic and so on .
After the aim and mod of using in practice, the underground waters can be divided in drinking, technical, mineral, industrial and thermal. These kinds of underground waters can be found on all the territory of the Republic of Moldova .
The underground drinking waters are stored in the Quaternary, pontician, meotician, sarmatian, cretacic and silurian rocks. The others aquifers contain salted waters (30 and 80,0 and more g/dm 3 ). About 16% of artesian waters have used in the centralized alimentation with water in the Republic of Moldova . The freatic waters are used for non-centralized water supply. Its used volume in the rural localities in comparison with other water sources constitutes 95 – 100%.
On the territory of the Republic of Moldova there are about 6600 deep artesian wells . In 2002, only 3,100 of them were estimated to be operational. The rest of them were abandoned and presently they do not belong to any legal owner. The freatic groundwater is used intensively in rural area being supplied through some 250,000 shallow wells and springs.
The deep groundwater reserves are, according to an estimate made in 1981 for a period of 25 years, 3,173,000 m 3 /day. The reserves of shallow groundwater have not been estimated yet, but it is known that some 50,000 m 3 of shallow groundwater are used per day.
The underground technical water is of the same age like the drinking waters. In some cases the same shallow wells are used for supply with technical and drinking water, but like a rule the technical water is used in boiler rooms, zootechnic things, agriculture and so on. From the total sum of water resources 2602,0 thousands m 3 /day consist the drinking water resources and 573,0 thousands m 3 /day - technique waters. Data's of the volume used of technique water are missing.
The Republic of Moldova has a large spectrum of underground mineral waters. The aquifers of different ages are situated on the depth 200 –1000 m. Nowadays are known 16 deposits of mineral water and 13 deposits are on the stage of research. The mineral waters are divided in 2 categories: mineral drinking waters and therapeutically waters.
The mineral waters can be found on all territory of the Republic of Moldova . The most known deposits are: Soroca, Varnita, Balti, Racoarea Codrilor, Chisinau, Camenca, etc. Its mineralization is equal 1,0 –10,0 g/dm 3 . The therapeutically mineral waters can be found in Northeast of the country and contain sulfur hydrogen, iodine, bromine and other chemical elements (lithium, radon, strontium, boron).
The industrial waters contain rare chemical elements, which can be extracted from water and used in different practices and industries. In our country this kind of water is spread in South, North- East, North-Vest into Mesozoic and Paleozoic rock.
The more spreader are deposits of water with iodine etc. The mineralizing is equal to 1 – 120 mg/dm 3 , iodine – to 1 –60 mg/dm 3 , bromine – to 20-250 mg/dm 3 and He to 15 ml/dm 3 .
Water ecosystem (River Nistru)
The thermal waters are spreader in the river Prut valley and in South of the Republic of Moldova . The age of the voters is different, with subterranean position between 100-1000 m and more. The temperature of water constitutes 20 ° -80 ° C; the debit is of 10 – 100 m 3 /day. The thermal water is ununiformly spreader on territory of Republic of Moldova . The most important resources of these waters are concentrated in valleys of the rivers Nistru and Prut .