Variation in Groundwater Levels
Variation in Groundwater Levels
In the course of 1992 and the spring or 1993, groundwater levels dropped several meters in the region between the Rivers Danube and Tisza, more specifically in the southern part thereof, which aggravated the damage caused by the droughts. Incidentally, groundwater levels beneath most of the areas utilised by agriculture were situated at depths which directly or indirectly influenced the water supply of the topsoil layers. While most of the Great Plain’s area was covered in wetlands, swamps and bogs, there was always sufficient water to create the local precipitation. River regulation and the draining of the swamps and bogs eliminated this natural water reserve, and the region had to gradually adapt to the water quantities supplied by winter and springtime rains.
In 1970, during the great flood on the River Szamos, it rained practically every day on the affected area, and precipitation was unusually abundant in comparison with other areas of the country.
Prior to the 1980s, the historical average for the groundwater level in the Great Plain was 2 to 3 meters, which can be considered favourable for the vegetation.
Moreover, a drastic depression in ground water levels began from the early 1980s in the area between the Rivers Danube and Tisza, with the groundwater reaching the lowest Level of all time between 1990 and 1993, i.e., the unusually low-lying groundwater could not moisten the topsoil, or rather it could only replenish lost water to a very limited extent.
The winter of 1995/96 and the year of 1996 abound in extremes and unusual events (e.g., the flood of December 1995; the unusually long, snowy and severe winter; the abnormally abundant rains of May; and the rainstorms, hail and tornadoes of June).
After the mild and often snowless winters of past years, the winters of 1995/96 and 1996/97 were considered quite abundant in snow, perhaps even unusual in some respects.
In 1995, winter arrived unusually early – in early November – therefore, the winter of 1995/96 was reckoned not from December but November.
