Search Results

You are looking at 1 - 3 of 3 items for

  • Author: Karolina Smarzyńska x
Clear All Modify Search
Open access

Zygmunt Miatkowski and Karolina Smarzyńska

Abstract

The goal of the paper was to determine surface water resources of an agricultural watershed representative for the areas of intensive crop production in the Kujawy region. This area is characterised by the lowest average annual precipitation in Poland and high water demands related to the intensive crop production.

Hydrological studies were carried out in 2007–2011 in the upper Zgłowiączka River watershed located in the eastern part of the analysed region. Over 90% of the study area is used as an arable land.

Water velocity in the river bed and water level were measured at the outlet of the watershed in the river cross-section Samszyce.

The upper Zgłowiączka River has a snow-rainfall hydrological regime, strongly modified by anthropogenic activities related to the intensive crop production and installation of subsurface drainage system. The study period was characterised by very large temporal variability of hydrological conditions. The mean annual outflow coefficient amounted to 18% and varied highly in time: from 3% in the average years to 62% in the abnormally wet 2011. Average discharge (SSQ) in the Samszyce river cross-section was equal to 0.25 m3·s−1, and the mean unit outflow – to 3.2 dm3·s−1·km−2. The results of the study show that disposable surface water resources of the Kujawy region are very small, especially in the summer half-year. Thus, their utilization as a potential source of water for crop irrigation can be taken into account only, if water excesses will be retained within the watershed and used in conjunction with groundwater resources.

Open access

Karolina Smarzyńska and Zygmunt Miatkowski

Abstract

Soil and Water Assessment Tool (SWAT) ver. 2005 was applied to study water balance and nitrogen load pathways in a small agricultural watershed in the lowlands of central Poland. The natural flow regime of the Zgłowiączka River was strongly modified by human activity (deforestation and installation of a subsurface drainage system) to facilitate stable crop production. SWAT was calibrated for daily and monthly discharge and monthly nitrate nitrogen load. Model efficiency was tested using manual techniques (subjective) and evaluation statistics (objective). Values of Nash–Sutcliffe efficiency coefficient (NSE), coefficient of determination (R 2) and percentage of bias for daily/monthly discharge simulations and monthly load indicated good or very good fit of simulated discharge and nitrate nitrogen load to the observed data set. Model precision and accuracy of fit was proved in validation. The calibrated and validated SWAT was used to assess water balance and nitrogen fluxes in the watershed. According to the results, the share of tile drainage in water yield is equal to 78%. The model analysis indicated the most significant pathway of NO3-N to surface waters in the study area, namely the tile drainage combined with lateral flow. Its share in total NO3-N load amounted to 89%. Identification of nitrogen fluxes in the watershed is crucial for decision makers in order to manage water resources and to implement the most effective measures to limit diffuse pollution from arable land to surface waters.

Open access

Jan Brzozowski, Zygmunt Miatkowski, Damian Śliwiński, Karolina Smarzyńska and Maria Śmietanka

Application of SWAT model to small agricultural catchment in Poland

Poland is obliged, like the other EU countries, to implement the Water Framework Directive - WFD (2000/60/WE) by the end of 2015. The main objective of WFD is to provide normative quality of all water resources. To reach this goal reduction of water polluter emission to the environment is needed. Our project focuses on pollution from agricultural sources which share in global pollution is high and growing still. As a pilot area, where the WFD is going to be implemented, small agricultural Zgłowiączka catchment was chosen.

The state monitoring of surface water quality for the catchment is conducted in three points along the Zgłowiaczka River. In each of these three points, nitrates concentration periodically significantly exceeds the allowable value of 50 mg NO3·dm-3. The highest average monthly values of nitrates concentration in years 1990-2007 occur in February, March and April, which indicates on agriculture as a source of pollution. The Zgłowiaczka catchment is an area where reduction of nitrogen run-off from agricultural lands to water resources is especially needed. The main topic of the research carried out in the Polish-Norwegian project is to propose different means for reduction of migration of nitrate to surface water based on modeling approach. In the paper a conception of creating buffer zones using SWAT model is presented. We considered fitting the buffer zone width, depending on the flow rate of water flowing from the fields to the stream. Using SWAT model interface a map of potential flow under the conditions of the intensive precipitation was generated. The next step was distribution over the whole Zgłowiączka catchment, places with high density of the temporal streams network. It was done using GRASS program. The map of stream "density" was done by assigning the raster number which is the sum of raster in the neighbourhood (radius of neighbourhood smaller or equal 25 raster). The choice of the most endangered subbasins was done on base of visual evaluation of the surface flow density map.

It is visible in the results that filter strips on endangered areas are far more effective and therefore more required. If the width of the vegetated buffer strips is not sufficient, it will not attain the desired effectiveness. Conversely, if the width is too great, it will cause agricultural land waste, preventing farmers' interest in cooperating with environmental preservation efforts. For the above reasons, it is important to set a reasonable width range. According to the results we are suggesting wider buffer zones in endangered subbasins and narrow in other subbasins.