ABSTRACT. – Changes of the groundwater regime in the area located between the Rivers Danube and Tisza. Flatlands, especially the Great Hungarian Plain (also known as Alföld) play a significant role in the economic life of Hungary and play a determining role in agriculture and sylviculture. The hydrographical relations of flatlands define the framework of crop farming, within this the changes and movement of ground water in space and time.During the last decades the ground water regime of the Great Hungarian Plain has gone through significant changes. In certain regions, especially in the higher parts of the area located between the Rivers Danube and Tisza (also known as Duna-Tisza köze) the ground water level was significantly and permanently below the average of many years, which created new conditions and risks mainly for agriculture and forest management.
Key words: flatland, alluvial plain, groundwater, groundwater monitoring well, ground water level decline, risks, natural environment.