LONG-TERM GROUNDWATER REGIME TRENDS IN THE AGRICULTURAL AREAS

Abstract

Long-term data on hydrological regime change of the groundwater situated in moraine sandy loam and peat in Lithuanian karst zone presented in the article. The aim of the paper was on the basis of long-term groundwater studies to determine the water level trends.

Groundwater level fluctuations mainly dependent on the ground type. The nearest land surface groundwater level (61-174 cm) was measured in peat soil (well 1), in mineral soil (well 2) was deeper (309-584 cm). Correlation between data of the annual precipitation and groundwater level in mineral soils (r² = 0.416, t_{act .}= 3.48>t_95%=1.74) was more significant than in peat soils (r²= 0.185,  t_act.=1.96 >t_95%=1.74). The highest fluctuations of groundwater level was determined in mineral soil (well 2). According to Mann-Kendall test, the groundwater level significantly increased in February, April and December. Due to warmer winters decreased the duration and depth of the frost, frequent thaw, this cause increased feeding of aquifer in winter.

Keywords: groundwater level, karst zone, mineral soil, peat soil

Article DOI: http://doi.org/10.15544/RD.2017.107