observation of underground water level in the area of forest estate "sremska mitrovica " during 2000 and 2001

Abstract

Observation of underground water level in the area of "Jasensko-Belilo", which belongs to the Forest Estate "Sremska Mitrovica", started in 1999. The measurements were performed by means of 2 piezometers set up approximately perpendicularly to the river Sava, forming profile number 1 (Fig.1). The results of these measurements (Fig. 2, 3) show a significant lowering of groundwater level in 2000. The reason is most likely the unfavorable rainfall amount and distribution during that year (Table 2). A much better situation was during 2001 when the minimal groundwater level was up to 2 meters and it was considered to be the result of a favorable amount of rainfall and its distribution during the year (Tables 2, 3). It was noticed that Carpinus betulus appears instead of flowering ash (Fraxinus ornus), which is a good sign that generally the level of underground water is lowering. Also, the phenomenon that pedunculate oak (Quercus robur) gradually loses its natural regeneration capability also confirms the trend of lowering underground water level. If this trend continues, oak will be in a very near future naturally substituted by less valuable species, probably Turkey oak (Quercus cerris). If groundwater wells along the river Sava reach the vicinity of this area, which is a plan for the Belgrade city water supply, the trend of groundwater table lowering will be even more expressed and it will certainly endanger the existence of all valuable forest species in this area.