Irrigation of ornamental gardens-Dr. Árpád Tóth (ed.)

Irrigation water
Water is a product that occurs on and below the surface of the earth.It is a natural resource that is in constant circulation and whose quantity does not vary significantly. Since ancient times, water has played an important role in shaping life on earth, production and socio-economic development. Almost all aspects of modern socio-economic life are linked to water. Water and society are in constant interaction.
From the plant's point of view, water is a source of food.and a means of transport for food, and a means of transport through evaporation.protection against excessive warming, provides the necessary tension in the plant cells, andand finally, through its constituents, it is an irreplaceable nutrient.
The utility of water is its natural properties which make it suitable for meeting human needs.
These economically significant properties are:
(a) its forms,
(b) its biological,
(c) its physical and
(d) its chemical properties.
(a) The main characteristics of the forms in economic terms can be summarised as follows:
Surface waters are characterised by their high mass, the ability to move due to the difference in elevation of the watercourses, the time and spaceThey are characterised by a high degree of variability in volume over time and space, rapid recharge, significant erosion and sediment transport, and high bio-organism content. The economically important characteristics of evaporating waters are that they vary rapidly in space and time, have a large macro- and microclimatic variability, and are highlymicro- and microclimates and play a self-cleaning
role in the water cycle.
Groundwaters have a larger volume of water stored at any one time than the surface waters of continents, and their capacity for movement is significantly smaller. The spatial and temporal variability of their volume is smaller and their recharge is slower. They have a lower content of living organisms and are therefore more suitable for drinking water and micro-irrigation.
b) The biological properties of water are of great economic importance. Its versatile physiological role is well known. As a basic element of plant life, it also plays a crucial role in agricultural production. Under domestic conditions, the production of 1 kg of plant dry matter requires 250-1000 l of water. The fertility of the soil, the basis of crop production, is also dependent on water conditions, but the fertility of the soil is also dependent on the water content of the soil.However, soil conditions can also modify the water balance (runoff, evapotranspiration).
For many organisms, water is a medium that provides a habitat. It is through the life functions of beneficial micro-organisms that grow in water that the natural biological self-purification of water takes place. Among the harmful biological properties, water also harbours viruses and bacteria that are harmful to health.
c) The most important of the physical properties of water is its positional energy, which is derived from its topography and can be converted into other energies with relatively favourable efficiency. The property of water to entrain and drift bodies of greater specific gravity than itself is the basis of natural soil erosion.
The high specific heat of water is used in the climate forcing of the seas, in heat transfer and heat extraction.
d) The chemical property of water is that it is a constituent of many compounds and reacts readily with a large proportion of substances. In many cases, this chemical property has harmful effects, such as the so-called "water vapour", which can impair the stability of concrete and reinforced concrete structures.
The first step in planning irrigation is to clarify the possibility of obtaining water. In the water balance of Hungary, the revenue side is estimated at about 168 km3 per year.
Of this, 112 km3 comes from across the border, 56 km3 falls in our country, of which 5 km3 run off, leaving 117 km3 of water on our southern border. The volume of water flowing in can be considered stable in the long term, as the catchments of our major rivers are located in
high mountain ranges (Alps, Carpathians). The daily flow, synchronised with precipitation, can change towards the extremes. In the case of the Danube, the hydroelectric power plants in Austria store a significant amount of water and smooth out fluctuations in the water volume.
The amount of irrigation water officially used today is about 0.3 km3 per year. This amount is within the margin of error of the annual water balance estimate and does not significantly affect the stocks.