Global warming is one of the most important reasons for the drought. 2024 is the next warmest year ever measured. Each successive month breaks the infamous temperature record compared to previous years. In short, the Earth's temperature is rising and along with this phenomenon, water is becoming increasingly scarce.
This year in terms of hydrology has been quite kind anyway. There were periods of snow cover in winter, the beginning of spring was quite wet, followed by a hot May and a hot June with thunderstorms and heavy rainfall. Nevertheless, we are talking about drought, which has already become a common phenomenon in our country
– says Dr hab. Iwona Wagner the Department of UNESCO Chair on Ecohydrology and Applied Ecology, Faculty of Biology and Environmental Protection, University of Lodz.
There are four types of droughts:
- atmospheric,
- agricultural (soil),hydrological and
- hydrogeological drought.
Atmospheric drought depends on the precipitation balance, i.e. the ratio between the amount of precipitation and how much water evaporates, explains Prof Wagner. – Now we are observing increased precipitation, but at the same time we are experiencing such high temperatures that evaporation is even higher. The latest drought report from the Institute of Soil Science and Plant Cultivation (IUNG) indicates that this has been worsening. For the period from 1 May to 30 June 2024, the average Climatic Water Balance (CWB) value for the country was 121 mm. This means that during this period, the amount of water evaporated from the surface of our country was 121 mm greater than the amount received with rainfall. This is a significant water deficit.
Agricultural drought, on the other hand, occurs when we see soil drying out. Over the past two months, it has affected more than 70% of municipalities in Poland, causing more than 20% yield losses compared to multi-year values. – Indeed, the effects of soil drought can most easily be seen in agriculture: plants grow worse, wither, flower less and bear less fruit. However, it is important to remember that this type of drought does not bypass non-agricultural areas either and its effects can also be seen in natural systems – adds Prof Wagner.
Hydrological drought takes place when the water level in rivers drops while hydrogeological drought when the groundwater level drops. – At present, according to official meteorological data, the latter two types of droughts do not occur in Poland, but it must be remembered that not all rivers, especially small ones, are monitored on an ongoing basis – says Prof Wagner.
Hydrogeological drought is the most dangerous one as it is most difficult to reverse – Groundwater is excessively brought to the surface because we use it in households, industry and increasingly also in agriculture. Meanwhile, this is an exploitation of a resource that we should start treating as non-renewable – alarms Prof Wagner. – Groundwater resources, although considered significant in Poland, are renewed in the perspective of tens or even hundreds of years. Bringing this high-quality water to the surface and pouring it onto quickly evaporating lawns or using it for washing cars is extremely wasteful.
Dr hab. Iwona Wagner
We see dry river beds more and more often in Poland, a phenomenon that did not occur in this part of Europe a dozen or so years ago. – This happens even in the east of the country, which is a wetland area and has so far been perceived as a kind of sponge. Now, even in non-industrialised areas, water levels are dropping and the soil is drying out, mainly due to high temperatures and evaporation – adds Prof Wagner
The effects of drought are easy to predict. Firstly, we should expect an increase in food prices, not only of vegetables and fruit, but also of cereals, dairy products and meat. We can expect water rationing in the near future. – In one of the Spanish regions, Catalonia, at the beginning of this year a regulation was introduced to reduce water consumption, which requires its reduction in agriculture by 80% and in cattle breeding by 50% - says Prof. Wagner. – It is not difficult to imagine how this type of regulation will affect food production and prices, and this is happening now and may soon also apply to our country.
However, the drought is not just affecting agriculture. Most Polish towns and cities are supplied with water from groundwater; a reduction in the groundwater level could mean problems with access to drinking water. – Already, dozens of appeals have been issued by local government units to reduce water consumption. These include requests not to water lawns, not to fill household swimming pools and to refrain from washing cars. There are several hundred such appeals every year – adds Prof Wagner. For now, these are appeals, but we can expect restrictions in the near future.
In Poland, 64% of people live in cities, i.e. in a hot, over-dried environment. – This is not good for our health; over-drying increases asthma, allergies, chronic diseases, respiratory and cardiovascular diseases – adds Prof Wagner.
It will also become increasingly difficult to relax by the water. – There will be fewer places to rest, water quality is also deteriorating and blue-green algae blooms are increasing. These are all effects of drought and high temperatures – says Prof Wagner.
What to do? Is there still a chance to prevent these changes? Firstly, carbon emissions need to be reduced in line with current assumptions. In February, the European Commission unveiled an ambitious new target to reduce net greenhouse gas emissions by 90% by 2040 compared to 1990. The entire world should achieve emission neutrality by 2050. – We also need to start thinking seriously about water – says prof. Wagner. – We need to change our thinking about water management and start treating it as a priority – both globally, from the country's point of view, but also at local levels. The EU Water Framework Directive obliges Member States to manage watersheds. Each river catchment is a basic area for space management and all decisions in its area should be made knowing its water balance. – We need to know how much water goes into the catchment, what its ability to retain water is and how much water we can use for which purposes. To improve the availability of water resources, we should increase the number of forests, wetlands and meadows. In forested and agricultural areas, the creation of ponds, i.e. small natural reservoirs with lots of plants, is recommended – says Prof Wagner. – These are small changes that can significantly improve the hydrological situation. The recently hotly debated proposal for a regulation of the European Parliament and of the Council on the restoration of natural resources (Nature Restoration Law) is precisely the law whose implementation, at negligible cost, will greatly help in the fight against drought.
There are many small and inexpensive solutions that can be implemented. The idea is to retain water that escapes into rivers and through rivers into the sea in the landscape. And in cities this problem is even greater, because after each rain, water is drained via concrete surfaces into the sewage system and carried outside the city. – Cities must change their thinking about water. Every city with more than 100,000 inhabitants has a municipal climate change adaptation plan that includes so-called blue-green infrastructure, i.e. areas of greenery and open water – says Prof Wagner. – The problem is that not all cities take these provisions seriously, and again, we are talking about small and relatively inexpensive solutions that can have a very positive effect, provided they are introduced universally.
First of all, we need to move away from levelling the terrain. – Developers really don't have to flatten every piece of land – Wagner says. – Leaving unevenness or small depressions can, in the long run, improve the attractiveness of the housing estate under construction and will retain water in many places, allowing it to soak in. It will provide coolness, greenery, but also the presence of birds and small animals. Such solutions have already been used successfully for years abroad.
Another solution is to unseal surfaces or not to seal newly created surfaces during the investment process. – These are simple ideas using various types of grates and permeable surfaces that will direct water from rainfall into the soil and not into the sewage system – explains Prof. Wagner. Another important point is the management of rainwater from roofs. – You can try green roofs, but this is quite an expensive solution and is only possible in new buildings – says Prof. Wagner. – However, rainwater can be brought from roofs to rain gardens, reservoirs, absorption basins or ponds. This is my favourite solution because it is very conducive to biodiversity.
The next point is the drainage of water from roads and streets, which is necessary for the safety and passability of cities. – But the water does not have to be discharged into the sewage system, it can flow onto the lawn. We just need to remember that water usually flows downwards, so lawns should be lower than roads, which, for some reason I don't understand, is not remembered in our country – says Wagner.
Tree planting is still the cheapest and most effective solution. The cost of planting one tree is relatively low, given that it grows over time and is able to retain up to several hundred litres of water on its crown, trunk and in its root system. It also improves soil structure, promoting soil retention. However, we must provide trees with access to rainwater so that they do not have to be watered "from the tap".
These are all solutions that do not generate huge costs but can significantly improve urban living comfort and effectively combat drought. – It is important that they are applied universally, because a single green roof and a single pond will do nothing to deal with the increasingly urgent problem of drought, adds Prof Wagner. – A change in thinking about water is needed.
Source: Faculty of Biology and Environmental Protection, University of Lodz
Text: Justyna Kowalewska (3PR), Michał Gruberski
Photo: Iwona Wagner