The aim of the study was to evaluate the precipitation needs of mid-late and late potato using the method of cluster analysis. The research material was based on the results of COBORU (Research Centre for Cultivar Testing) experi-ments carried out in 1972–2001 for the pattern of mid-late and late potato grown on soils of rye complexes, at 23 research stations all over Poland. Meteorologi-cal data: monthly precipitation and the mean temperature of air during the vege-tation of potato were gathered from all the meteorological points functioning at COBORU experimental stations or from the nearest IMGW (Institute of Meteorology and Water Management) stations. For the evaluation of precipitation needs of potato the method of generalized cluster analysis was used. As a result of the method used, three clusters were selected. They differed significantly with regard to the values of 7 variables taken into consideration. The highest yield of potato (cluster 1) was obtained at average values of mean air temperature in the period from May to September (15.2oC), lower than the aver-age precipitation total in May (45 mm), moderate precipitation in June (65 mm) and more than average precipitation in July (90 mm), August (75 mm) and in September ...

Method of cluster analysis in homogenous catchments identification considering flood indexes and selected physiographic characteristics

One of educating activities aims is characteristic, grouping and classifi-cation of phenomena, objects and behaviors. Division of some group of objects, subjects or devices into subgroups plays very important role in standardization operations. A result of objective analysis of the tested set structure is the possi-bility to determine mutual relations between elements which create the set. This is particularly important in hydrology, especially in modeling of processes that oc-cur in catchments or drainage basins. Relations between catchments characteris-tics and hydrologic models’ parameters are extremely important in estimation of parameters of statistic distributions, evaluation of changes in catchments and prognosis of hydrological phenomena in uncontrolled catchments. The knowledge of the spatial distribution of hydrological characteristics is more and more often used in water management, especially during water management plans creation in the area of catchments or drainage basins. In order to estimate interesting hy-drological characteristics in uncontrolled catchments the method of regional fre-quency analysis is applied, which allows to allocate areas of homogenous type of the analyzed phenomenon. To allocate the homogenous areas methods of two or more variables regression, cluster analysis, kriging or artificial neural networks are applied, too. Grouping methods base on the internal division criterion, which is mathematic ...

THE APPLICATION OF THE STATISTICAL METHODS TO GROUNDWATER CHEMISTRY BASED ON EXAMPLE THE MAƁOPOLSKA VOIVODESHIP AREA

The aplication of selected methods of the hydrogeochemical statistical analysis is presented in the paper. Statistical methods were applied to initially identify of the formation processes of water chemical composition of groundwater within the Lesser Poland Voivodeship area. As results of the cluster analysis three clusters' set of forming the chemical composition of groundwater's was distinguished (fig. 2). A set of three factors forming the chemical composition of groundwaters was distinguished as a result of the factor analysis (fig. 3, tab. 1). All statistical methods used were found out to be susceptible upon hydrogeochemical anomaly. Taking into account the observed susceptible of cluster analysis its application makes it impossible to describe enough correctly the formation of the chemical composition of groundwaters within the study area. Using the factor analysis attained the best results but this method is also susceptible upon anomaly cases. The statistical methods used were found out as helpful. However, the interpretation of research results without the additionally factors is intractable, especially for the case of hydrogeochemical anomaly. ...