The paper presents the results of 8-year investigations (1995–2002) carried out in two different objects – Samotwór and Miękinia near Wrocław. The investigations included analyses of the quality of ground and surface water, both for inflow and outflow. It was found that in the conditions of Polish agriculture, outflow control belongs to the most helpful ways of managing water resources. The final effects of outflow control depend mainly on hydrogeological conditions and exact respectation of the dates and heights of water damming with regard to hydrological events and agricultural land-use system.

The paper discusses the influence of the river training works done along the Łososina River, one of the Carpathian tributaries of the Dunajec, on the changes in the conditions of bedload transport in the river. Special attention is given to the parameter of unit bedload transport. It was important that the river training works reduced the bedload transport in the Łososina because this also decreased the sediment input to the Czchów water reservoir. Before the works the Łososina, having quite a large catchment (A = 410 km²), carried a significant amount of sediment. The main conclusion of the paper is that a properly executed river training reduces bedload transport along the river.

Model studies investigated six designs of a rapid hydraulic structure and their influence on the river bed downstream of the structure. The results of the laboratory experiments were compared with those of the calculations based on ten scour-forecasting formulae worked out by the following authors: Veronese, Chividini, Eggenberg, Jaeger, Chian Min Wu, Mavis and Laushey, Van der Meuler and Vinje, Martins, Mason, and Yang. The best results were obtained using the Jaeger, Van der Meuler and Vinje, Eggenberg, and Mavis and Laushey formulae. The worst results were achieved with the Veronese and Mason formulae.

A forecast about the process of silting was prepared for two small reservoirs – Brzóza Stadnicka (the higher one) and Brzóza Królewska (the lower one) – located on the same, hydrologically uncontrolled, stream Tarlaka. An analysis of the silting of the lower reservoir was performed taking into consideration the trap efficiency of the higher reservoir. The amount of the incoming sediment was calculated using the DR-USLE method. The trap efficiency was determined using Brune’s method, which allowed the use of Gončarov’s method in the next step. The forecast suggests that the life time of the Brzóza Królewska reservoir may be prolonged from 77 up to 124 years.

Research of water relations existing on formerly arable lands covered by forest was done within Wrocław between April 2000 and October 2002. The existing natural water system and the land reclamation system with two small reservoirs were found to have an advantageous effect on the amount of soil retention in the adjacent lands. Due to that system the moisture reserves in the soil profile were about 30–120 mm greater than in the area outside the range of influence of controlled water management, and at the end of growing seasons during the years with low precipitations and high air temperature the ground water table was around 40 cm higher.

Assessment of the present condition of the plants that were introduced to the banks of the water reservoir “Domaniów” to protect them against abrasion shows that about 25% of the trees and shrubs planted died back. The causes are heavy frosts, inundation, competition from grasses and damage done by people. The seedlings which survived develop rather poorly, probably because of the low soil fertility.Apart from the plants that were introduced for consolidation purposes, there are also numerous selfsown seedlings of trees and shrubs, originating from the neighbouring forests, orchards and trees. The seeds are dispersed by wind, forest animals and people. Among the seedlings those of Betula pendula, Pinus sylvestris and Quercus robur occur the most frequently. It is supposed that the existing plant succession would lead to the development of mixed pine forests which in the soil-and-climatic conditions of that area are climax associations.

Studies conducted during 1997–2002 in Jastków in the Lublin province investigated the use of a pond to remove contaminants from partly purified sewage discharged from a household soil-plant treatment plant. The pond (area 1190 m², mean depth 0.8 m) is situated in the bottom of the Ciemięga river valley and is supplied with pressure water. The water plants of the pond belong to the most eutrophication-resistent plants and play an important role in the treatment of household sewage by creating very good conditions for further elimination of the load of contaminants from the sewage discharged from the soil-plant bed. The studies showed that the pond plays a purifying function. The values of the analysed indicators of contamination are significantly lower for the water from the pond than for the sewage discharged from the soil-plant bed. The average values of COD_Cr and BOD₅ make it possible to include the water of the pond in purity class II or III. Only the mean concentrations of total phosphorus in this water exceed the norm for class III. The studies suggest that ponds should be used as an additional purifying element accompanying soil-plant sewage treatment plants.

The effects of sewage treatment by a municipal sewage treatment plant were studied in Biała Podlaska. The object of study is a typical mechanical-biological sewage treatment plant with active deposit, receiving municipal and industrial sewage from Biała Podlaska and its surroundings. The plant has been designed to receive 13 500 m³ of sewage per 24 hours. At present the effective amount of the sewage treated is 11 000 m³ per 24 hours. In 2001 the mean efficiency of pollutant removal was the following: BOD₅ – 98.7%, COD_Cr – 95.4%, total suspended solids – 94.8%, total nitrogen – 81.7%, ammonium nitrogen – 98.3%, and total phosphorus – 91.5%. The results show that the sewage treatment plant in Biała Podlaska performs well which makes it possible to minimise a negative effect of sewage on the environment. The plant is an example of good design that may be followed in other objects of this type.

The paper presents the results of investigations into the efficiency of treatment of the waste rainwater drained from the Lublin Agricultural-and-Horticultural Market in Elizówka. The assessment of the treatment efficiency was carried out on the basis of four series of measurements made in different seasons of the year. The sewage samples were taken from two storage reservoirs. The following physicochemical properties of waste rainwater were determined: pH, temperature, conductivity, suspended matter, dissolved oxygen, BOD₅, COD_Cr, N-NH₄, N-NO₃, N-NO₂, PO₄, SO₄, K, Cl and Fe. In the sewage from reservoir No 1 (tight clarifier) the admissible values were exceeded several times; this referred particularly to the levels of suspended matter and conductivity. In the sewage from reservoir No 2, in which there is infiltration into the ground, all components, apart from pH which showed excessive values, were in the standard range. The values of the majority of indicators remained on a similar, normative level. The concentration of chlorides increased after snowmelt runoffs, but even at that time it did not exceed the admissible value. A considerable decrease in the quantity of most impurities after the passage of water from the clarifier to the retention-and-infiltration reservoir indicates that the treatment plant functions properly.

The pipe drainage runoff and the flow in a ditch within the “Szewce” object situated in Lower Silesia and the physicochemical composition of water in that object were investigated in the years 1977–1980, when the object was irrigated using municipal sewage, and during 1999–2002, i.e. eight years after the irrigation was ceased. The results show that irrigation with municipal sewage did not cause permanent changes in the soil-water environment. When the irrigation was stopped, the pipe drainage runoff and the flow in the ditch markedly decreased. There was also a decrease in the values of BOD₅ and the concentrations of phosphorus and ammonium nitrogen in the tested waters, and an increase in the concentrations of nitrate nitrogen and total nitrogen. The results obtained in 1999–2002 do not differ from the results achieved in other objects under a traditional agricultural land-use system.

An investigation was conducted to assess changes in the iron concentration in water flowing through a floating bed constructed of foam polystyrene grains. The filters were operated with three filtration velocities. Another aim of the study was to determine the amount of iron separated from water in the sedimentation process. The efficiency of bed flushing was investigated with the use of water, water and air, and water after prior air washing. The results of the study show that the iron concentration in water can be reduced by approximately 70–80%, but sole sedimentation accounts for about 40%. The best procedure for backwashing was air scouring before backwashing with water.

The distribution of temperatures in the ground in the surroundings of a hollowed fruit store during the storage period was calculated using the results of measurements made under real operational conditions. The effect of the object on the temperature in its vicinity was shown in diagrams depicting the fields of temperature in the ground. It was found that in the middle period of the storage season the isotherm 0 °C reached the depth of 1.5 m. Thus, the range of freezing established for the ground adjacent to the cooling chamber exceeded the standard depth of ground freezing accepted for the climatic zone appropriate for the location of a hollowed cold store.

Artificial intelligence enjoys great interest in several fields of science. Neural networks, novel technologies loosely based on biological learning, can be used to discover (learn) patterns that are not readily apparent in data. The paper focuses on some key aspects of applying such research techniques to shape rural space. Kohonen’s algorithm (Self-Organizing Map – SOM) was found to be useful in spatial structure analysis for separating areas with homogeneous features. The procedure was described and structured into a method comprising several stages.

Non-agricultural activity is the main factor in the economic development of rural areas. The paper describes and analyses the spatial diversity of the basic resources and non-agricultural activity of rural areas in the Kujawy-Pomorze province and attempts to assess the level of economic development of these areas with the use of two methods, one of which is evaluation of the gross value added. It was found that the highest level of development is characteristic of suburban rural areas situated in the vicinity of the largest and economically strong cities like Bydgoszcz and Toruń.

Studies of water, mud and rush vegetation in Lake Trackie, carried out in 2001 to determine the influence of anthropogenic factors, showed that the phytolittoral area decreased in comparison with 1991 [Ciecierska 1994]. One hundred and fourteen plant species were recorded; none of them was a protected species or one of special natural value. Sixteen plant communities were identified, five of which created a protection zone of the lake. As compared to the state of 1991 [Ciecierska 1994], there was an increase in the area covered by mud and rush communities and a reduction in the area of water phytocenoses. The ratio of the area occupied by water plants to that with rush vegetation indicates that the latter plays now a more important role in the lake. The rise in the values of the synanthropisation index (W_s) and the synanthropic quotient (Il_syn) points to the increased impact of endogenic factors of anthropogenic origin on the phytolittoral of the lake, resulting in its dysharmonious development. The values of the phytocenotic diversity index (H) remained stable during ten years, which suggests that the lake is able to recover if the inflow of allogenic nutrients is cut off.

Studies of the accumulation of heavy metal ions in the organs of common broom Cytisus scoparius were carried out in 2002 on the population occurring in the area of the former shooting range “Muszaki-Jagarzewo” on the Masurian Plain. The herb, roots, flowers and seeds of common broom contain alkaloids, mostly spartein and sarotamine, which makes them useful in treating heart and kidney diseases. The levels of metal ions in the organs of this plant, which is abundant in the study area, were determined to assess whether the plants growing there are suitable as a herbal raw material. Manganese and zinc were accumulated the most intensively by the common broom organs, with the levels being the highest in the leaves, stems and flowers, and the lowest in fruits.

The aim of the research was to evaluate the influence of middle-field forest patches on the agricultural plantations situated in the areas threatened with water erosion. The yielding of winter wheat and winter rape was investigated during 1997–1999 in the area of Chełm (Lublin province). The studies covered also chosen physical and chemical properties of soils. The crops were harvested from the plots located at different distances from the edge of a forest patch with trees 5 m high. It was found that the properties of soils did not have any significant impact on the grain yield of wheat or the seed yield of rape. The poorest yields were observed in the immediate vicinity of the forest patch. The width of the area affected by the patch did not exceed the height of the trees.

The present study concerns the effect of weather conditions and of the biometrical characteristics of forest on the course and dynamics of changes in air temperature in the vertical profile of forest. The aim of research was to compare the values and patterns of air temperature in a spruce stand and on a mountain meadow. The investigations were conducted in a 30-year-old spruce stand situated in the area of the Experimental Forest Station in Krynica. The stand grows at an altitude of 800 m on a gentle slope of eastern exposure, on the mountain forest site, in the conditions of a temperate cool climate. The meadow is located under the same geographical and climatic conditions, at a distance of 200 m from the wall of the stand. In July 1996, two 34-hour series of measurements were performed. Air temperature was measured every hour with Assmann’s psychrometer at a height of 5, 50 and 150 cm above ground level. In the spruce stand the temperature differences in the vertical profile were greater than in the open area. In the forest and on the meadow the averages of air temperature were similar. Maximum temperatures occurred near the active surface and were higher in the open area. Minimum temperatures at both measuring stations were similar. The daily amplitudes of air temperature increased towards the active surface. The vertical gradients of air temperature in the forest were always negative while on the meadow they changed according to the time of the day, wind velocity and precipitation.

The paper describes a method for preparing a climatological elaboration in the form of a calendar. The climatological calendar shows the time and space distribution of weather types (as defined by Woś [1999]) throughout the year. Thus, it can provide a useful tool for scheduling work in forestry, horticulture and agriculture, and for planning and organising climatic treatment programmes and leisure, tourist and recreation activities.