"Municipalities as integrators and coordinators
in adaptation to climate change"
Hungary is a water superpower! – many people say. However, this statement is only partially true. Why? This is illustrated in the figure below. We obtain water from three different sources in Hungary: rainfall, groundwater resources and rivers. Let’s look at these three sources of water separately.
Unfortunately, there is not enough rainfall. It is true for most part of the country that every year there is less rainfall than it could evaporate if there was enough water. In the Great Plain, for example, the average annual precipitation is around 500 mm, but the evaporation potential is 800 mm, therefore 300 mm of rain is missing each year. Another problem with precipitation is the uneven distribution: some fall in the winter, which is not useful, and a significant part in the form of big thunderstorms, falling suddenly, which cannot penetrate to the ground, but flows through canals, streams and rivers. According to climate models, the distribution of precipitation will become even more uneven with global climate change, although it is already today.
The table below shows how many days do the 50%, 80%, and 90% of the annual precipitation fall at the LIFE-MICACC pilot sites, based on 50 years of rainfall data. The numbers are very similar by pilot sites, for example, half of the annual volume falls everywhere in less than three weeks.
1CARPATCLI database, based on daily rainfall data from 1961 to 2010
Our other source of water is groundwater. A lot of water is stored here safely, such as subsoil water, formation water, karst water. Under the surface, the impurities spread more slowly, the water stored here is clearer; it is not by chance that our drinking water comes from here (from sources and wells), not directly from rivers and lakes, which are immediately hit by pollution. In addition, groundwater is not directly in contact with air, so it does not evaporate and run out. The quality and quantity of groundwater is also much better protected than surface water, so we call it ‘water bank’.
If there is not enough rainfall somewhere, water shortages are often made up pf groundwater. That in itself is not a problem, because the groundwater is renewed. But it is a problem, if their rate of renewal us slow, often much slower than the rate at which we extract them. And while the exploitation is increasing, the rate of regeneration is slowing down: in fact, groundwater supplies can be renewed by allowing rainwater and rivers to seep into the soil from the surface. Wetlands, lakes, swamps, floodplains and forests provide the needed surface for this. In Hungary, however, most of the wetlands have been eliminated and many forests have been converted into arable land. As a result, groundwater levels in many parts of Hungary are decreasing. Every year we put less into the water bank than we lose, and our savings are dwindling.
Our third major source of water would be rivers, which is why they say Hungary is a great water power. Rivers carry about twice as much water as the rainfall in the Carpathian Basin each year. However, rivers are confined by dams, and their water does not overflow into floodplains, do not discharge into branches and backwaters, so they cannot replace groundwater and are not utilized.
It’s like saying that a lot of tourists visit Hungary, so we are a tourism power, even though they would just travel through the country on a highway, from Romania to Austria. If they not get off the highway they’re not tourists, just transit. The same is true of water: if we do not drive it out of the river bed, it will not be profitable.
Finally, in Hungary the water management approach today is based on the drainage of water: inland sewerage systems drain 1, 77 million m3 of water into rivers each year, from areas that are often droughty a few months later. Thanks to drainage-centric management, rivers discharge more water at the southern borders of the country (116 km3) than they flow in at the north (109 m3). Every year we lose about 7 km3 of water, which equals three and a half waters of Lake Balaton.
Hungary’s water balance based on the Hungarian National Atlas
So Hungary is constantly aridificating, our water supplies are dwindling, though we could have plenty of water if properly managed. Instead of draining the water, the solution would be to keep retain the water, in a small, natural way. The LIFE-MICACC project is working on this.
Written by Mátyás Farkas, WWF Hungary