The quantitative and qualitative evaluation of water resources in the Polish rivers

There is a tendency in water management to identify the resources of surface waters with the river discharge expressed by the intensity of the flow. However, such evaluation of resources is not advisable bacause of the difficulties in water-economic balancing of the basin, since it does not take into account the water contained in the wetted profile of the river bad. With heavy pollution of the water flowing in the river bed this fact may have a considerable influence on the accuracy of the balance. The above reasons have become a basis for the introduction of a new means for the evaluation of resources of flowing waters, namely a momentum, i.e. the quantity of the water motion in a stream, expressed by the equation. ln ZA= ∫ Q · dl lm or with Q = FV ln ZA= ∫ F · V · dl lm where: 1n - lm - the length of the relevant river section in m, Q - the mean flow intensity at the given section of the stream in m³ s⁻¹, F - the prewetted cross section of the stream bed in m² V - the velocity of water flow in ms⁻¹. The evaluation of the quality ofwater resources has been carried out for 83 rivers in the Vistula basin and in 52 rivers in the Oder basin by means of the stream momentum method. These resources are identified with SNQ (Mean Minimum Discharge). It has been found that in the Vistula and in the Oder basins the smallest quantities of resources were clustered in class I of cleanness (about. 0,5%). The heavily polluted waters and out-of-class waters comprised as much as 93% of all water resources in the Vistula basin, and 81 % in the Oder basin. The situation is better in Pomerania region, where class I waters make 10% of resources, and only 25% are waters in class III and off-limit cleanness waters. The non-deficiency rivers, fully capable of satisfying unlimited needs, are characterized very heavy pollution. Almost half of all the water resources in deficiency rivers, of limited posibilities of satysfying the needs, are outside any classification. The mean momentum duration of the polluted water resources (class III and off-limit cleanness) is 8- 10 days. The best situation prevails in the rivers of Pomerania (1-4 days), the worse is in the Noteć (51 days), the Bóbr (24 days) and the Oder (29 days)

Evaluation of the surface water discharge in the Raszynka River catchment area

W pracy omówiono warunki przyrodnicze i użytkowanie ziemi w zlewni Raszynki wpadającej do Utraty, scharakteryzowano dostępne dane hydrologiczne i sposoby ich wykorzystania w opracowaniu charakterystyk hydrologicznych. Zlewnia nie jest kontrolowana, lecz istnieją fragmentaryczne dane o stanach wody z okresu 1953–1960 i kilka pomiarów przepływu. Dane te, wraz z wynikami pomiarów własnych, wykorzystano w prezentowanych analizach. Ponadto posłużono się danymi dla profilu Krubice na Utracie, której zlewnię przyjęto jako analog w obliczaniu charakterystyk przepływu wody w Raszynce. Oceniono przepływy charakterystyczne i prawdopodobne dla profilu w Michałowicach na Raszynce (profil zamykający zlewnię o powierzchni 61,5 km&#178).The paper discusses natural conditions and land use in the Raszynka River (a tributary of the Utrata River) catchment area. The available hydrological data and the methods of their utilization have been characterized with a view to determining hydrological characteristics. The catchment is not monitored, there exist, however, some fragmentary data about water levels from the period of 1953–1960 as well as several discharge measurements. These data, together with the author´s own measurements, have been used in the presented analysis. Furthermore, the authors have used the data for the Krubice profile on the Utrata River whose catchment area was assumed as an analogue in calculating discharge characteristics in the Raszynka River. The characteristics and probable discharges have been estimated for the Michałowice profile on the Raszynka River, which closes the catchment area of 61.5 km&#178