Hydrologiczne aspekty funkcjonowania opóźniaczy odpływu w małej zlewni leśnej

• Autorzy: Palczyński M. , Paluch J. , Paruch A. , Pulikowski K. , Wojtowicz J.

Warianty tytułu

EN

Hydrological aspects of operation of run-off delayers in the small forest catchment area

• Języki publikacji: PL

Abstrakty

EN

A basic aim of actions, which have been undertaken in a research forest catchment area, was to slow down the water cycle and increase the area retention. There is assumption that they bring about a decrement of flow culmination of high waters and an increment of normal and low water flow. This is a way to equalization of water run-off, which is very important during water deficits of growing season. Within the scope of research done on the research catchment area two facilities, which was called by them author - J. Paluch a "run-off delayer" were installed. They operation based on a proper selection of inlet pipe for free flow of water in a specific volume, e.g.: a mean water flow enabled but bigger water flows kept until they reach an overflow crown, then overflow via the overflow crown and flow through a horizontal pipe (roat pipe culvert) in direction to lower parts of watercourse. In a sense the operation of run of-delayer can be comparable to the operation of dry storage reservoir with bottom outlet and tower overflow. Detailed descriptions of run off-delayers are available in a few reports [5, 6, 7, 8]. The researched object is located in the vicinity of Milicz town on the area of Landscape Park of Barycz Valley. The research has been done since January 2001. Except for two run-off delayers situated in the line of one watercourse also 4 water gauges, 4 limnographs and 6 piezometers were mounted (tab. 1). All of these facilities near these two run-off delayers as well as on an area so-called control catchment area - L 4 (free from run-off delayer) are installed. Meteorological conditions of hydrologic year are presented on Figure 2 and in Table 2. Total monthly precipitation during summer period was by far the higher than multiannual values. A range of a test of basic hydrological parameters was limited due to the values presented not including the whole hydrologic year. A course of changes of water stage recorded on water gauge 1, above run-off delayer 1, are presented on Figure 3. Larger runoff occurred after intensive precipitation in July 2001 brought about in a short time an accumulation of material layer about 20 cm thick. Fraction 0,5-0,1 mm there predominante due to being from 76% to 86% of sample masses. The next Figure (4) is about small reservoir which has been formed above lower run-off delayer II. Several diameters of inlet was replaced during research. Crosses on the X axis describe dates of diameters change. There is also a vertical line representing the height of overflow crown. The research also included water flow rate measurement on water gauge L 3, below the reservoir at run-off delayer II. A mean water flow in the research period amounted to about 0,01 m3/s. However, maximum value of July 20 (after precipitation 43 mm) amounted 1,85 m3/s (Figure 5). A rate of sedimentation and bank caving processes was by far the higher during high summer precipitation. That is way the run-off delayers was constructed based on both: an empirical formula which is recommended by the guidelines design for bridges and culverts [12] and Błaszczyks guidelines [1]. Because of subjective character of empirical formula, there is very often discrepancy between values calculated and those really measured [2]. Technical parameters of the run-off delayer was exaggerated on purpose. A proper size of diameter of the lower hole (the bottom outlet) there is especially important. The size was replaced due to determination of an optimal diameter. There used to be a few diameters: an initial 20 cm, then 5 cm and also 0 cm (completely closure). At present, there is a diameter of 8 cm used successfully. A proper selection of technical parameters for the run-off delayer, mounted in the small catchment areas without hydrological characteristic, is a problem which still need to be resolved. The other problem is a difficulty of exploitation, because of occurrence of the sedimentation process on a station of upper watercourse. Maximum water flow registered on cross section L 3 was almost 200 times as much as mean calculated value of water flow during the period of this research. Because of such difference between maximum and mean values of water flow into such small watercourse as researched one is, there are justified reasons for keeping high waters after precipitation, increasing the area retention and equalizing the water flow. Optimal using of resources of water from periodical excess is especially essential on the forest areas. There are opportunity to increase a natural water-control effect of forest by means of installations that delay the water run-off. A comparative analysis of selected limnograph readings from measurement points located in cross sections L1, L4 and L2, L3, follows that a clear difference occurred between times of rainfall raised-water stage and equalization this water which were recorded in cross sections L1, L4 and cross sections L2, L3. The foregoing differences were 2 to 4 hours earlier in cross sections L1, L4 than L2, L3. Although a comparison of limnograph readings from L1, L4 follows that time of beginning of rainfall raised-water stage was similar in both cases, the culmination (maximum stage) occurred even about 9 hours earlier in cross sections L4 than L1. In the other case, the culmination recorded in L4 occured also about 9 hours earlier than in cross sections L2, L3. At present, there is difficult to specify to what extent the time differences can follow from the operation of run off-delayers or from natural diversity between catchment areas and control-measurement cross sections, such as different size of catchment areas and natural slope of the lands. Not only is necessary to continue such research (which should take simultaneously both of scientific problems: environmental and technical) but also to receive results from a long time period and from a few researched objects as well as to make their wide, interdisciplinary interpretation.

Słowa kluczowe

PL

gospodarka wodna; obserwacje hydrologiczne; opady

• Wydawca: Wydawnictwo Politechniki Krakowskiej im. Tadeusza Kościuszki
• Czasopismo: Czasopismo Techniczne. Środowisko
• Rocznik: 2002
• Tom: R. 99, z. 5-Ś
• Strony: 85--95
• Opis fizyczny: Bibliogr. 12 poz., tab., wykr., il.

Twórcy

autor

Palczyński M.

• Instytut Kształtowania i Ochrony Środowiska Akademii Rolniczej we Wrocławiu

autor

Paluch J.

• Instytut Kształtowania i Ochrony Środowiska Akademii Rolniczej we Wrocławiu

autor

Paruch A.

• Instytut Kształtowania i Ochrony Środowiska Akademii Rolniczej we Wrocławiu

autor

Pulikowski K.

• Instytut Kształtowania i Ochrony Środowiska Akademii Rolniczej we Wrocławiu

autor

Wojtowicz J.

• Instytut Kształtowania i Ochrony Środowiska Akademii Rolniczej we Wrocławiu

Bibliografia

• [1] Błaszczyk W., Projektowanie sieci kanalizacyjnych, Arkady 1965.
• [2] Byczkowski A., Ciepielowski A., Warunki powstawania i metody obliczania wód wielkich w małych zlewniach, Gospodarka Wodna nr 11/1974, s. 423-429.
• [3] Mapa gospodarczo-przeglądowa gleb i siedlisk Leśnictwa Dziewiętlin, Biuro Urządzania Lasu i Geodezji Leśnej w Brzegu (stan na dzień 01.01.1996).
• [4] Materiały do Bilansu Wodnego Polski XI "Opady zmierzone w dorzeczu Odry w latach 1920-1940, Wydawnictwo Komunikacyjne, Warszawa 1955.
• [5] Palczyński M., Paluch J., Próba określenia możliwości sterowania spływem wód powodziowych, Zeszyty Naukowe Akademii Rolniczej we Wrocławiu Nr 387, Konferencje XXVII, Zagrożenie powodziowe w Sudetach, s. 79-85.
• [6] Paluch J., Koncepcja rozwoju systemów przeciwpowodziowych w strefach wododziałowych cieków wodnych, Wiadomości Melioracyjne i Łąkarskie nr 2/1998, s. 65-70.
• [7] Paluch J., Paruch A., Pulikowski K., Palczyński M., Wojtowicz J., Preliminary estimation of effective use of retention of small catchment areas for flood protection. Electronic Joumal of Polish Agricultural Universities. 2001 Volume 4 Issue 2 Sedes Environmental Development. www.ejpau.media.pl/series/volume4/issue2/environment/art-04.html.
• [8] Paluch J., Wykorzystanie retencji zlewni cząstkowych do ochrony wód powierzchniowych i podziemnych, cz. I, Gospodarka Wodna nr 5/1999, s. 172-176, cz. 11, Gospodarka Wodna nr 6/1999, s. 213-216, cz. III, Gospodarka Wodna nr 7/1999, s. 258-262.
• [9] Partyka T., Lasy w środowisku przyrodniczo-geograficznym Polski - stan i tendencje rozwoju, Sylwan nr 1-2/1989, s. 12-14.
• [10] Tyszka J., Hydrologicznie użyteczne funkcje lasu, Gospodarka Wodna nr 7/1985, s. 158-159.
• [11] Wiszniewski W., Atlas opadów atmosferycznych w Polsce 1891-1930.
• [12] Wytyczne projektowania obiektów i urządzeń budownictwa specjalnego w zakresie komunikacji, Światła mostów i przepustów WP-D 12, Wydawnictwo Katalogów i Cenników, Warszawa 1973.