Hidrológiai Közlöny 1988 (68. évfolyam)

6. szám - Pálfai Imre: A belvizek hidrológiai jellemzése

PALFAI I.: Bclvizhidroldgia 329 Salamin P. 1942. Tanulmány a hazai belvízrendezésről. Hidrol. Közi., 22, 1—6: 76—122. Salamin P. 1966. Vízrendezések. Mérnöki Továbbképző Intézet kiadványa. M. 166. Tankönyvkiadó. Budapest. Sági K. 1968. A nyári félévi esőkből öntözött területen keletkezett lefolyás ós a lefolyásra ható néhány tényező. Öntözéses Oazd., 6, 1: 17—23. Szeifert Oy. 1965 A Nyírség komplex vízgazdálkodása. Vízügyi Közi., 47, 4: 435—474. Szesztay K. 1956. Belvízmennyisógek meghatározása és előrejelzése csapadékból. Vízügyi Közi., 38, 2:215— —299. Szőcs J. 1967. Az 1965—1966. óvi téli-tavaszi belvízvédekezés. Vízügyi Közi., 49, 1: 5—30. Trümmer Á. 1945. Az 1940—42. óvi vízmentesítési munkálatok. Vízügyi Közi., 27, 1—i: 28—42. Vágás I. 1967. Az 1966. évi belvizek keletkezését kialakító hidrológiai tényezők. Hidrol. Közi., 47, 1: 34—30 Vágás I. 1984. Az árvízi hurokgörbe. Hidrol. Közi., 64, 6: 333—341. Kézirat beérkezett: 1987. november 2. Közlésre elfogadva: 1988. május 22. Hydrology of undrained runoff in Hungary Pálfai, I. Abstract: A report is presented on the liydrological study on inundations by undrained runoff, which was compiled for the Hungarian National Master Plan of Water Management and expanded subsequently. As such it supplements the Master Plan and earlier papers alike (OVH, 1984; Pálfai, 1986). The objective is to present -— relying on the observation (lata available at the district water authorities — a comprehensive picture about the undrained runoff situation in Hungary. The more relevant earlier publications based on measurements and observations are listed in the introduction (Chapter 1). The characteristics of inundations by undrained runoff are dealt with in Chapter 2. The variations over the year of inundations surveyed between 1961 and 1985 in the area of the Lower Tisza Valley District Water Authority (denoted as VI in Fig. 2) are illustrated in Fig. 7. and expressed in 1000 hectare units. The three typical inundation seasons: winter-spring, summer and autumn are clearly reflected thereby. The national peak values, the annual peak values and the total magnitude of the areas inundated annually are compiled (hectare units) in Table 1. The largestannualinundations related to the size of the catchment, in hectares/km

2 units are presented in Table 2 for the six largest plain-land catchments (I to VI). The distribution (probability of occurrence) of inundations is illustrated in Fig 3. The winter-spring inundation (1970) will be seen to last substantially longer than in summer (1975) from Fig. 4. The average depth of inundation is normally 10—20 cm, exceptionally 40—50 cm. The geographic variability of inundations is represented in terms of relative frequency (for the eastern part of the Hungarian Plains) in terms of relative frequency on Fig 5. From the entire map (OVH, 1984) it will be seen that in Hungary 1,9 million hectares are exposed to inundation by undrained runoff. The extent of such exposure can be estimated for any particular area usingEq.(l) in combination with similar, but more detailed maps. Surface runoff is considered in Chapter 3. The variations in runoff for the 1961—1985 period is illustrated in Fig. 6. (mm/d units) for the left-hand region along the Lower Tisza (denoted by the serial no. 33 in Fig. 11). The distribution of the annual and seasonal (winter-spring, summer, autumn) maxima is shown in Fig. 7. The runoff peaks of 10% probability of occurrence in tde other régiónál-units were given in an earlier report (Pálfai, 1986). The maximum values range between 3—4 mm/d and 0,4—0,5 mm/d. When comparing the data the size of the catchment can be eliminated using a correction factor calculated from Eq. (2), where A and A„ are the catchment sizes and n = = 0,16—0,50. The duration surface of runoffs on the left-hand side of the Lower Tisza is shown in Fig. 8. The results of distribution studies on monthly runoffs for the same region are summarized in Fig. 9, while the data on annual runoff L, annual precipitation P and the annual runoff coefficient (a) calculated as the ratio thereof are compiled in Table 3. The distribution of annual runoffs is to be seen in Fig. 10. The national average of plain-land runoff for the years 1961—1985 is 40—45 mm. The geographical distribution was shown in earlier papers (Pálfai, 1985; 1986). The normal values of the annual runoff coefficient in the catchments of the Hungarian Plains are compiled in Table 4 and illustrated in Fig. 11. The average related to the Plains is 0,076. The inundation : runoff relationship is considered in Chapter 4. The runoff rating curve (Pálfai, 1986) and the runoff loop (Fig. 12) are suggested for expressing this relationship. By summing consecutively the water volumes over the inundated areas and those yielded by runoff it is possible to estimate the maximum of the total undrained runoff, which may be two to three times as large as the runoff peak. Keywords: inundation by undrained runoff, exposure, runoff, runoff coefficient PÁLFAI IMRE szakmai munkásságának összefoglalóját a Hidrol. Közt. 1987/2—3. számának 69. oldalán közöltük.