Tomasz Kowalik, Włodzimierz Kanownik, Andrzej Bogdał, Agnieszka Policht-Latawiec
Uniwersytet Rolniczy, Kraków
Abstract
The aim of the paper was an assessment of the change in the structure of small upland catchment use on quality parameters of water flowing away from its area. The objective was realized through analysis of values and concentrations of selected water physicochemical indices, which were obtained by systematic research conducted during two periods, when the catchment use changed significantly.
The research was conducted in the Rzyki G catchment situated in the Beskid Mały Mountains area, in the village of Rzyki, in the western part of the Malopolska Region. It is the basic catchment of the Wieprzówka river, which flows into the Skawa River in its lower course. The catchment, of 47.50 ha and mean width of 0.525 km, has a slightly elongated, compact shape and clearly formed valley, through which the only watercourse, 0.575 km long Rzyki G is flowing. Mean weighed height of the area is 425 m a.s.l, whereas an average land slope is 12.2%. The catchment is covered by relatively shallow, skeletal and strongly acid dystrophic brown soils, which are characterized by a considerable compactness, high capillary capacity and poor permeability. Rzyki G catchment is of a typically agricultural character. In 1995–1996 the arable lands, covering 68.7% of the total area, prevailed in the structure of agricultural lands. Forests with plantings and grasslands constituted respectively 8.4 and 16.2% of the area. Non-agricultural land occurred sporadically (2.4%), whereas 4.3% of the area was used as built-up area. 15 years later (the period of 2010–2011) the arable land acreage diminished by 46.6%, whereas the share of permanent turf covered area, including grasslands, increased by 29.4%. Also the catchment afforestation rate grew slightly, as well as the built-up area, respectively by 2.7 and 1.7%.
Hydrochemical analyses were conducted in the years 1995–1996 and 2010–2011. Water samples were collected from the Rzyki G watercourse between once and four times a month. pH was measured on-site, whereas the concentrations of ammonium and nitrate nitrogen, phosphates, sulphates, calcium, magnesium, sodium, potassium, chlorides and iron were assessed in laboratory by means of reference methods. The empirical data base was analysed statistically using selected descriptive statistics and non-parametrical U Mann-Whitney’s significance test. Water quality was determined on the basis of the domestic executive act, in compliance with 2000/60/WE Directive of the European Parliament and council dated 23 October,2000. Apart from hydrochemical analyses, a detailed inventory of the area was conducted during both periods of investigations. Using cartographic materials and GIS tools, the current state of use and physiographic characteristics of the catchment were developed.
On the basis of the data analysis it was found that in result of the change in the catchment area use, from arable lands to permanent turf-covered areas, concentrations of most of the analyzed chemical indices of water in the Rzyki G watercourse, i.e. biogenic substances (N-NH4+, N-NO3-, PO43-), as well as sulphates and iron decreased significantly. Mean values of the indices allowed to classify the water in both periods to I class of the ecological state, however in single water samples from 1995–1996 period, the values of ammonium nitrogen and phosphate concentrations classified water to the state below good, whereas in case of nitrate nitrogen to II class. Fulfillment of the requirements stated by the Framework Water Directive concerning the achieving and maintenance of good water quality will require a new approach to shaping the agricultural space, including the changes in the way of management and use of strongly sculptured catchments. Obtained research results confirm the advantageous effect of turf covered area on water quality and therefore the advisability of using ecotones along watercourses and water reservoirs as biogeochemical barriers limiting migration of fertilizer components from agricultural areas to surface waters.
Słowa kluczowe
użytkowania terenu zlewni, wskaźniki jakości wody
Effect of Change of Small Upland Catchment Use on Surface Water Quality Course
Keywords
catchment land use, water quality parameters
Pełny text / Full text
PDF (Polish)
