Water retention and runoff formation in the Krkonoše Mts

ŠÍR M. & TESAŘ M. 2013: Water retention and runoff formation in the Krkonoše Mts. Opera Corcontica 50/S: 97–106.

Water retention and runoff formation in the Krkonoše Mts Retence vody a formování odtoku v Krkonoších MILOSLAV ŠÍR & MIROSLAV TESAŘ Academy of Sciences of the Czech Republic, Institute of Hydrodynamics, Pod Paťankou 30/5, 166 12 Praha 6, CZ, [email protected], [email protected]

Abstract Water retention and runoff formation have been studied in two basins located in the Giant Mts (Krkonoše in Czech, Karkonosze in Polish). The Labe basin (LB: area 53.06 km2, altitude 692 to 1,503 m a.s.l.), and the Modrý Potok basin (MP: area 2.62 km2, altitude 1,010 to 1,554 m a.s.l.) are located in the same natural conditions. The bedrock is formed by rocks of the crystalline complex. The prevailing soil types are Humic Podzols, Lithic Leptosols, and Dystric Histosol. The vegetative cover is formed by grass and spruce forest in the lower part, and artic-alpine tundra with dwarf pine in the upper part above the timberline. In September 2001, unusual rainfall of 348 mm/mo (LB) and 364 mm (MP) fell. Consequently, a runoff of 281 mm/mo (LB) and 262 mm/mo (MP) was generated. The maximum retention of water in the basin was 80 mm (LB) and 140 mm (MP). At the moment of peak runoff, water retention in the basins captured 40 % (LB) and 65 % (MP) of previous cumulative rain. In the Labe basin, anomalous fill-spill effect was observed: water supplied by rain caused a decrease of 40 mm in the soil water content. This resulted in a reduction of the water retention by 5 mm in the Labe basin. The conclusion, gained in both basins, is that the retention of water in the basin and particularly in the soil profile significantly reduced the peak runoff from the watershed. Keywords: mountain hydrology, runoff formation, catchment water retention, soil water movement

Abstrakt Ve dvou povodích v Krkonoších se studovala retence vody a formování odtoku. Povodí Labe (LB: plocha 53,06 km2, nadmořská výška 692 až 1 503 m n. m.) a povodí Modrý potok (MP: plocha 2,62 km2, nadmořská výška 1 010 až 1 554 m n. m.) se nacházejí ve shodných přírodních podmínkách. Geologické podloží je tvořeno krystalinikem. Převažujícími půdními typy jsou podzoly, leptosoly a organosoly. Vegetační pokryv je tvořen v nižších polohách travním porostem a smrkovým lesem. Nad hranicí lesa se nachází arkticko-alpinská tundra s klečovým porostem. V září 2001 na obě povodí spadla série dešťů s neobvykle vysokým úhrnem 384 mm/měsíc (LB) a 364 m/měsíc (MP). Následkem byl vysoký měsíční odtok, který dosáhl 281 mm/měsíc (LB) a 262 mm/měsíc (MP). Maximální retence dešťové vody v povodí v srpnu 2001 dosáhla 80 mm (LB) a 140 mm (MP). Při největším průtoku v uzávěrovém profilu povodí dosáhla retence vody v povodí 40 % (LB) a 65 % (MP) kumulativní srážky od počátku měsíce do okamžiku největšího průtoku. Na měřícím stanovišti v povodí Labe (LB) bylo pozorováno anomální proudění vody v půdě, při kterém déšť vsakující do půdy způsobil pokles zásoby vody v půdě o 40 mm. Tento jev se projevil snížením retence vody v celém povodí o 5 mm. V obou povodích byl získán shodný závěr, že retence dešťové vody v povodí, a zvláště v půdním profilu, podstatně snižuje maximální odtok vody z povodí při dlouhodobých deštích o vysokém úhrnu. Klíčová slova: horská hydrologie, formování odtoku, retence vody v povodí, pohyb půdní vody

Introduction Several crucial factors contribute to runoff formation; rainfall intensity and its total, water retention in a catchment, and hydrophysical properties of soil and subsoil including water retention in the soil cover. A key issue in the research of runoff is the evalua-

tion of the share of each of these processes affecting runoff formation (KOSTKA & HOLKO 1997, TESAŘ et al. 2004a, 2004b, 2008, 2010, TROMP-VAN MEERVELD & MCDONNELL 2006a, 2006b). It was found that water retention in the soil and the entire basin significantly influences runoff formation (KOSTKA & HOLKO 1997). The crucial role

98

OPERA CORCONTICA 50/S 2013

of soil water in the runoff formation is well known because soil cover creates large water reservoirs (KUTÍLEK & NIELSEN 1994). In the Czech Republic, the retention capacity of the soil cover is one order higher than the volume of all artificial and natural water reservoirs. Typical water retention capacity of the soil cover ranges from 60 to 90 mm in the mountainous and submontane basins (DOLEŽAL et al. 2004). This study is devoted to the analysis of the runoff formation in two mountainous basins located in the Giant Mts, taking into account soil water movement and water retention in the catchments.

Material and methods Water retention and runoff formation have been studied in two basins in the Giant Mts (Fig. 1). The Labe basin and the Modrý Potok basin are located in the same natural conditions. They differ mainly in the catchment area: the Labe basin is 20 times larger than the Modrý Potok basin. Nevertheless, in terms of experimental hydrology, both cases can be regarded as small basins (HERMANN & SCHUMANN 2010). The Labe basin is situated in the western part of the Giant Mts. The area of this basin is 53.06 km2. The highest point is the Vysoké Kolo Mt. (1,503 m a.s.l.) and the minimum elevation of the closing profile in the vicinity of Špindlerův Mlýn is 692 m a.s.l. The average annual rainfall total was 1,519 mm; average annual

Fig. 1. The location of the Giant Mts, the Labe basin, the Labská Louka stand, and the Modrý Potok basin in the Czech Republic. Obr. 1. Poloha Krkonoš, povodí Labe, stanoviště Labská louka a povodí Modrý potok v České republice.

depth of runoff was 1,271 mm; and the runoff coefficient was 0.84. Average annual discharge in the closing profile was 2.14 m3/s; a 100-year flood is 175 m3/s. The Labská Louka stand is located in the Labe basin, close to the Labe river headspring, at an elevation of 1,370 m a.s.l. The climatic conditions correspond to the characteristics of the cold climatic zone (the average air temperature in January is about –6 °C, in July from 10 °C to 12 °C). The mean annual precipitation total ranges from 1,300 to 1,500 mm. The Labská Louka stand is situated on the flush surface (peneplain) of the bedrock. It consists of biotitic granite. The depth of the weathered zone ranges from units to tens of metres. The prevailing soil type is Dystric Histosol (WRB 1998). The physical geographic situation of the Labe basin is depicted in Fig. 2. On the Labská Louka stand, a monitoring station is located in the area covered by grass (marked as LLUM in Fig. 2). The Modrý Potok basin is located in the eastern part of the Giant Mts. The area of this basin is 2.62 km2. The highest point is the Studniční hora Mt. (1,554 m a.s.l.) and the minimum elevation of the closing profile is 1,010 m a.s.l. There are deposits of fluvial or fluviodeluvial sediments along the Modrý Potok brook. The soil types are Humic Podzols and Lithic Leptosols (WRB 1998) with a very thin humic layer. Deeper soil of about 60 cm can be found in the bottom part of the valley. The original spruce forest is represented in the lower part of this basin, and artic-alpine tundra with dwarf pine covers the upper part above the timberline. Climatic conditions correspond to the characteristics of the cold humid climatic zone. The mean annual precipitation total ranges from 1,200 to 1,300 mm. The mean air temperature in July is 12.1 °C. The maximum retention of water in the basin is about 70 mm (TESAŘ et al. 2004a). The physical geographic situation of the Modrý Potok basin is shown in Fig. 3. A monitoring station is placed in a valley meadow located below the forest margin (marked as VM in Fig. 3). Monitoring stations in the Modrý Potok basin and the Labe basin are located at an aerial distance of 13 km from each other. The following parameters have been measured at each monitoring station: rain intensity and total, global radiation, air temperature at two levels (5 and 200 cm above the soil surface), soil temperature at three depths (15, 30, 60 cm), the tensiometric pressure in the soil cover at four depths (15, 30, 45, 60 cm), and the averaged soil moisture content in the soil layer of 0–60 cm. Tensiometric pres-

ŠÍR & TESAŘ: WATER RETENTION AND RUNOFF

99

Fig. 2. Physical geographic situation of the Labe basin with closure profile in the vicinity of Špindlerův Mlýn (CPSM) and monitoring stations located in the Labská Louka meadow stand (LLUM – the Labská Louka upper meadow). Obr. 2. Fyzicko-geografická situace povodí Labe s uzávěrovým profilem v blízkosti Špindlerova Mlýna (CPSM) a poloha monitorovacích stanic umístěných na Labské louce (LLUM – Labská louka, horní louka). Fig. 3. Physical geographic situation of the Modrý Potok basin and position of monitoring stations. MSV – meteorological station Výrovka chalet; CPMP – closure profile of the Modrý Potok basin; VM – valley meadow located below the forest margin; SF – mature spruce forest; UM – upper meadow located above the forest margin; DW – dwarf pine forest located above the forest margin. Obr. 3. Fyzicko-geografická situace povodí Modrý potok a poloha monitorovacích stanic. MSV – meteorologická stanice u chaty Výrovka, CPMP – uzávěrový profil povodí Modrý potok, VM – údolní louka pod hranicí lesa, SF – dospělý smrkový les, UM – horní louka nad hranicí lesa, DW – klečový porost nad hranicí lesa.

100


sure was measured by water tensiometers. The soil moisture was determined using high frequency permittivity measurement (LICHNER et al. 2004). All values were recorded at ten-minute steps. The discharge at the closing profile of the Modrý Potok basin was measured using a pressure sensor and recorded at ten-minute steps. Runoff depth from entire basin area was determined as a discharge in the closing profile of a basin divided by the catchment area. Hourly sums of precipitation total and runoff depth were used for evaluation of actual water retention in the Modrý Potok basin. To calculate the actual water retention in the Labe basin, hourly sums of precipitation total and runoff depth provided by the CHMI were used. Evapotranspiration from both basins was determined with the help of the method described in the article of PRAŽÁK et al. (1994) using hourly values of air temperature and hourly totals of global solar radiation measured in monitoring station placed close to the Výrovka chalet on the watershed divide between both basins (marked as MSV in Fig. 3). The time course of cumulative rainfall depth was obtained by adding hourly precipitation from the beginning to the end of September 2001. Similarly, the time course of cumulative runoff depth was obtained. Cumulative rainfall depth and cumulative runoff depth were expressed in millimetres of water column.

Actual water retention in an entire basin area was derived as the difference between the cumulative rainfall depth and cumulative runoff depth assuming negligible transpiration (CZELIS & SPITZ 2003). Thus, the determined value is actually an increase or decrease of water content in the basin to the unknown initial value at the beginning of September 2001. Actual water retention was calculated in millimetres of water column.

Results Seven distinctive rain events were observed in the Modrý Potok meteorological station and the Labská Louka stand in September 2001. Four major discharge events were caused by four rain events (Fig. 4). Rain courses were very similar so that distinctive rain events corresponded in both basins (Fig. 4). The beginnings and ends of rain events were almost identical, and monthly rainfall depths were very similar (Tab. 1). A difference of about 5% is smaller than the standard uncertainty of about 10%, which is caused by rain variability (LAPIN & FAŠKO 1997). Monthly rainfall depth in the range of 348–364 mm formed 23–24% of the average annual rainfall total. This means that the discussed monthly rainfall was extreme.

Fig. 4. Cumulative rain in the Modrý Potok basin and the Labská Louka meadow stand in September 2001. P1 to P7 denote distinctive rain events. Obr. 4. Kumulativní srážky v povodí Modrý potok a na stanovišti Labská louka v září 2001. P1 až P7 označují výrazné deště.


Tab. 1. Runoff coefficients in the Labe basin and the Modrý Potok basin in September 2001. Tab. 1. Odtokové koeficienty v povodí Labe a v povodí Modrý potok v září 2001. Monthly rain sum (mm)

Monthly runoff sum (mm)

Runoff coefficient (–)

Labe basin

348

281

0.81

Modrý Potok basin

364

262

0.72

In the Fig. 5, runoff and cumulative runoff in both basins are depicted. The runoff values in both basins were very similar (Fig. 5). The beginnings and ends of flood waves in both basins were almost identical, and the monthly runoffs of 262–281mm were very similar (Tab. 1). In the Labe basin, the maximum monthly discharge of 50.176 m3/s was reached at 10 am on 10th September. In the Modrý Potok basin, peak discharge of 1.501 m3/s was achieved about two hours later. The evapotranspiration was negligible (approx. 10 mm/mo) throughout September 2001, due to steady rain and low air temperature. Therefore, the actual water retention in a basin was derived as the difference between the cumulative rain depth and cumulative runoff depth from the entire basin supposing that the very small evapotranspiration can be ignored (CZELIS & SPITZ 2003).

101

Fig. 6 presents water retention in the Modrý Potok basin and the Labe basin and their difference in September 2001. The arrow “140 mm” denotes maximum water retention in the Modrý Potok basin. The arrow “80 mm” denotes maximum water retention in the Labe basin. The arrow “60 mm” denotes the maximum difference between water retention in both basins. As shown in Fig. 6, water retention played a significant role in runoff formation in both basins. The maximum water retention in the Modrý Potok basin during the rain P3 (at 8 am on 10th September) can be estimated at 140 mm. At this moment, the cumulative rain for September was 216 mm/mo. This means that 65% of the cumulative rain was stored in the basin and 35% formed cumulative runoff. The maximum water retention in the Labe basin during the rain P3 (10 pm on 10th September) was 80 mm (Fig. 6). At this moment, the cumulative rain for September was 200 mm. This means that 40% of the cumulative rain was stored in the basin, and 60% of the cumulative rain formed cumulative runoff. The amount of water retained in the basin at the time of maximum retention can be estimated as follows: 53.06 km2 x 80 mm = 4.3 million m3. This huge volume of water exceeded the total volume of 3.292 million m3 of the Labská reservoir located downstream of the closing profile of the Labe basin. The catchment area of the Labská reservoir is 60.54 km2, which is

Fig. 5. Runoff and cumulative runoff in the Modrý Potok basin and Labe basin in September 2001. D1 to D4 denote discharges caused by rain events P1 to P4 (see Fig 4). Obr. 5. Odtok a kumulativní odtok z povodí Modrý potok a povodí Labe v září 2001. D1 až D4 označují výrazné odtokové vlny zapříčiněné dešti P1 až P4 (viz obr. 4).

102


Fig. 6. Water retention in the Modrý Potok basin and Labe basin, and their differences in September 2001. Arrow 140 mm denotes maximum water retention in the Modrý Potok basin. Arrow 80 mm denotes maximum water retention in the Labe basin. Arrow 60 mm denotes maximum difference between water retention in both basins. Obr. 6. Retence vody v povodí Modrý potok a povodí Labe a rozdíl retence vody v obou povodích v září 2001. Šipka 140 mm značí maximální retenci vody v povodí Modrý potok. Šipka 80 mm značí maximální retenci vody v povodí Labe. Šipka 60 mm označuje maximální rozdíl retence vody v obou povodích.

Fig. 7. Water retention, cumulative rain, and cumulative runoff in the Labe basin in the period of 5–11th September 2001. P1 and P2 denote distinctive rain events; arrows RA, RB, RC denote water retention at times A, B, C. Obr. 7. Retence vody, kumulativní srážka a kumulativní odtok v povodí Labe v období 5.–11. září 2001. P1 a P2 značí výrazné deště, šipka RA, RB, RC značí retenci vody v okamžicích A, B, C.


close to the catchment area of the studied Labe basin 53.06 km2. This example shows why the flood risk in submontane areas, resulting from the small retention capacity of mountain basins, cannot be entirely eliminated by the construction of dams and reservoirs in river valleys, although they can significantly reduce flood damage. Fig. 7 illustrates water retention, cumulative precipitation and cumulative runoff in the Labe basin in the period of 5–11th September 2001. P1 and P2 denote distinctive rain events; arrows RA, RB, RC denote water retention at times A (at 10 am on 8th Septem-

103

ber), B (at noon on 9th September), and C (at midnight on 11th September). In time B, the water retention decreased compared to time A. Fig. 8 shows the same episode in the Modrý Potok basin. Fig. 9 represents the soil water content and cumulative precipitation in the Labská Louka stand in the period of 5–11th September, 2001. The arrow 40 mm denotes the drop in the soil water content between A and B (at noon on 9th September). At time A, the soil water content in the soil layer of 0–60 cm reached a maximum value of 238 mm. In the time interval A – B, the infiltration of 10-mm rainwater induced

Fig. 8. Water retention, cumulative rain, and cumulative runoff in the Modrý Potok basin in the period of 5–11th of September 2001. P1 and P2 denote distinctive rain events; arrows RA, RB, RC denote water retention at times A, B, C. Obr. 8. Retence vody, kumulativní srážka a kumulativní odtok v povodí Modrý potok v období 5.–11. září 2001. P1 a P2 značí výrazné deště, šipka RA, RB, RC značí retenci vody v okamžicích A, B, C.

Fig. 9. Soil water content and cumulative rain in the Labská Louka meadow stand in the period of 5–11th September 2001. Arrow 40 mm denotes the drop in the soil water content at time B caused by the fill-spill effect. Obr. 9. Zásoba vody v půdě a kumulativní srážky na stanovišti Labská louka v období 5.–11. září 2001. Šipka 40 mm značí pokles zásoby vody v půdě v okamžiku B způsobený anomálním prouděním vody v půdě.

104


the outflow of 37-mm water stabilised in the soil before the rain. Therefore, the total outflow of rain and soil water from the soil profile into the bedrock was 47 mm. This phenomenon, known as the fillspill effect, caused substantial drying of the soil cover (Fig. 9) and reduced the water retention by 5 mm in the Labe basin (arrow RB in Fig 7). Tab. 1 shows monthly rainfall totals, monthly runoff depths, and runoff coefficients in both basins. Runoff coefficient is the fraction of runoff depth and rainfall total. Monthly runoff coefficients in the range of 0.72–0.81 seem to be quite high; however, they closely match the long-term runoff coefficient of 0.84 in the Labe basin. The unusually high longterm runoff coefficient is mainly caused by the melting of the huge volume of snow accumulated in the highest areas of the basin in the spring.

Discussion The physics of the fill-spill effect is the subject of contemporary research activities (GLASS & YARRINGTON 2003, FÜRST et al. 2009). TESAŘ et al. (2004b) gave the following description of the fill-spill effect. In the basin Liz (Czech Republic, Bohemian Forest), two coupled anomalous phenomena in soil water flow were observed: (1) in some situations, the water supplied by rain caused a pronounced decrease in the soil water content. (2) In these periods, the soil water movement could be explained only by assuming an irregularly oscillating outflow of soil water into lower horizons. An explanation of the oscillatory discharge of soil water is given in the article by PRAŽÁK et al. (1992). When the soil moisture content exceeds a certain threshold value, gravity-driven flow of the soil water arises. In such a situation, a large volume of water starts to flow through the soil into the bedrock (spill phase). When the soil moisture content drops below the threshold value, gravity-driven flow vanishes and it is replaced by diffusion flow, during which water moves slowly from the soil into the bedrock (fill phase). Therefore, the fill-spill effect can be formulated as follows: There is a threshold value of the soil moisture content. If the soil moisture content is smaller than the threshold value, water is filling soil pores (fill phase) without leaking into the underlying bedrock. If the soil moisture content is greater, water is released from the soil (spill phase). In the Labe basin, the threshold value of the

volumetric soil water content is approx. 40%. This corresponds to the maximum value of the soil water content of 240 mm in the soil layer of 0–60 cm at time A (at 10 am on 8th September) in Fig. 9. The fill-spill effect is characterised by non-monotonicity of the soil saturation pattern: the soil saturation first increases (during the fill phase) and then, despite the continuous influx of rain water, it starts decreasing (during the spill phase). This non-monotonicity is called saturation overshoot. An example of the saturation overshoot is shown in Fig. 9. The spill phase begins in time A when the soil water content is maximal and ends at time B when the soil water content is minimal. Saturation overshoot in gravity-driven fingers was experimentally observed by GLASS et al. (1989), SELKER et al. (1992) and LIU et al. (1994) and many others. The most comprehensive experimental work was done by BAUTERS et al. (2000) and DICARLO (2004, 2007). FÜRST et al. 2009 explained why saturation overshoot can never be obtained as a solution of the Richards’ equation (KUTÍLEK & NIELSEN 1994). Consequently, this effect remains outside the scope of standard porous media flow models often used for description of the soil water movement. During the fill-spill effect, a large volume of water flows through the soil into the bedrock (TESAŘ et al. 2004b). Therefore, at the basin scale, this phenomenon creates some part of the runoff. Let us make a highly speculative estimate of the volume of water that was drained due to the fill-spill effect from the soil cover into bedrock in the period of 5–11th September, 2001 in the Labe basin. The quantity of water, which was released from the Labe basin during the fill-spill effect, can be estimated as follows: 53.06 km2 x 5 mm = 0.3 million m3. If we submit that the retention of water in the Labe basin in the absence of fill-spill effect would have increased by 10 mm, as in the Modrý Potok basin (arrow RB in Fig. 8), then this would be the discussed volume of 53.06 km2 x 5 mm + 53.06 km2 x 10 mm = 0.8 million m3. The size of the area probably affected by the fillspill effect can be ranged by these limits: minimum = 53.06 km2 x 5/40 mm = 6.6 km2, maximum = 53.06 km2 x 15/40 mm = 19.9 km2. This means that 13 to 38 % of the entire basin area could be affected by the fill-spill effect. The fill-spill effect often occurs at high soil saturation (TESAŘ et al. 2004a, 2008, 2010). This means that


hydrologic conditions, in which the fill-spill effect may occur, can be a source of flood risk, especially in the case of flash floods. The fill-spill effect was observed in the Bohemian Forest, the Giant Mts and other mountains (PRAŽÁK et al. 1992, TROMP-VAN MEERVELD & MCDONNELL 2006a, 2006b). Understanding of soil water movement and runoff formation enables an increase in the lead time of runoff prediction, which is important for the design of early warning systems for flash floods detection (NOAA 2010). As an output of the above described findings concerning the spill-fill effect affecting outflow of water from the soil cover the early warning system (EWS) for flash floods was designed and created in the head water region of the Giant Mts (TESAŘ & ŠÍR, 2013). The commonly used EWS has been supplemented by the monitoring of the state (using water tensiometers) and amount (with the help of soil moisture meters) of water in the soil profile.

105

a small basin should be the same as in a large basin assuming the same natural conditions (HERMANN & SCHUMANN 2010).

Souhrn Příspěvek analyzuje retenci vody a formování odtoku na příkladu povodí Labe a povodí Modrého potoka v Krkonoších. V září 2001 tato místa ovlivnila výrazná dešťová episoda, kdy úhrn srážek dosáhl 384 mm/ měsíc resp. 364 mm/měsíc. To se následně projevilo i ve zvýšené měsíčným odtoku. Anomální proudění vody v půdě (tzv. fill-spill efekt), které bylo zaznamenáno na sledovaném ploše v Povodí Labe, však může ovlivnit (snížit) retenční schopnost dešťové vody v povodí a zvýšit rychlost odtoku. To hraje významnou roli pro predikci bleskových povodní. Podrobný monitoring těchto procesů je základem pro vybudování systému včasného varování.

Conclusions In September 2001, unusual rainfall of 348 mm/mo in the Labe basin (LB) and 364 mm/mo in the Modrý Potok basin (MD) fell. Consequently, a runoff of 281 mm/mo (LB) and 262 mm/mo (MD) was generated. The maximum water retention in the basins was 80 mm (LB) and 140 mm (MD). At the moment of peak runoff, water retention in the catchment captured 40 % (LB) and 65 % (MD) of cumulative rain. In the Labe basin, anomalous fill-spill effect was observed: water supplied by rain caused a decrease of 40 mm in the soil water content. This resulted in reducing water retention in the catchment by 5 mm. The conclusion, gained in both basins, is that the retention of water in the basin and particularly in the soil profile significantly reduced the peak runoff. These results suggest that, in both basins, similar rain triggered similar runoffs events, regardless of their significantly different basin area. Therefore, it can be reasonably assumed that due to the large similarity of natural conditions, identical transport processes affected on runoff formation. Consequently, it is possible to consider that the results obtained in two studied small basins are representative for the whole Giant Mts. This finding confirms the basic idea of hydrological research conducted in two studied small basins: mechanisms of runoff formation in

Acknowledgements The work has been supported by the Technology Agency of the Czech Republic (Project TA02021451).

References BAUTERS T. W. J. DICARLO D. A. STEENHUIS T. & PARLANGE J.-Y. 2000: Soil water content dependent wetting front characteristics in sands. Journal of Hydrolology 231–232: 244–254. CZELIS R. & SPITZ P. 2003: Retence vody v povodí při povodních. Acta Hydrologica Slovaca 4, 2: 233–241. DICARLO D. A. 2004: Experimental measurements of saturation overshoot on infiltration. Water Resources Research 40: W04215, DOI:10.1029/2003WR002670 DICARLO D. A. 2007: Capillary pressure overshoot as a function of imbibition flux and initial water content. Water Resources Research 43: W08402, DOI:10.1029/2006WR005550.

106


DOLEŽAL F. KVÍTEK T. SOUKUP M. KULHAVÝ Z. & TIPPL M. 2004: Czech highlands and peneplains and their hydrological role, with special regards to the Bohemo-Moravian Highland. In: HERRMANN A. SCHROEDER U. (eds), Studies in Mountain Hydrology. IHP/ HWRP-Berichte 2: 41–56. FÜRST T., VODÁK R., ŠÍR M. & BÍL M. 2009: On the incompatibility of Richards’ equation and finger-like infiltration in unsaturated homogeneous porous media. Water Resources Research 45: W03408, DOI:10.1029/2008WR007062.

PRAŽÁK J., ŠÍR M., KUBÍK F., TYWONIAK J. & ZARCONE C. 1992: Oscillation phenomena in gravitydriven drainage in coarse porous media. Water Resources Research 28: 1849 –1855. PRAŽÁK J., ŠÍR M. & TESAŘ M. 1994: Estimation of plant transpiration from meteorological data under conditions of sufficient soil moisture. Journal of Hydrology 162: 409–427. SELKER J. PARLANGE J.-Y. & STEENHUIS T. 1992: Fingered flow in two dimensions: 2. Predictingfinger moisture profile. Water Resources Research 28: 2523 –2528.

GLASS R. J., PARLANGE J.-Y. & STEENHUIS T. 1989: Mechanism for finger persistence in homogenous unsaturated, porous media: Theory and verification. Soil Science 148: 60–70.

TESAŘ M. & ŠÍR M. 2013: Early Warning System for Flash Floods in the Krkonoše Mts. The Supplementum of Opera Corcontica 50: 107–112.

GLASS R. J. & YARRINGTON L. 2003: Mechanistic modelling of fingering, non-monotonicity, fragmentation, and pulsation within gravity/ buoyant destabilized two-phase/unsaturated flow. Water Resources Research 39: 1058 –1067.

TESAŘ M., ŠÍR M., KREJČA M., FIŠÁK J. & POLÍVKA J. 2010: Soil water movement during the extreme precipitation in the Šumava Mts and in the Krkonoše Mts in August 2002. Folia Geographica, Series Geographica – Physica 16: 67–73.

HERMANN A. & SCHUMANN S. (eds) 2010: Status and perspectives of hydrology in small basins. IAHS Publication 336: 316 p.

TESAŘ M., ŠÍR M. & DVOŘÁK I. J. 2004a: Vliv vegetačního porostu a jeho změn na vodní režim půd v pramenných oblastech Krkonoš (Influence of vegetative cover changes on the soil water regime in head water areas in the Krkonoše Mts). Opera Corcontica 41: 30–37.

KOSTKA Z. & HOLKO L. 1997: Soil moisture and runoff generation in small mountain basin. Publication of the Slovak Committee for Hydrology Vol. 2. Slovak Committee for Hydrology, Bratislava. 91 pp. KUTÍLEK M. & NIELSEN D. R. 1994: Soil hydrology. Catena Verlag, Cremlingen – Destedt. 370 pp.

TESAŘ M., ŠÍR M., LICHNER Ľ. & FIŠÁK J. 2008: Extreme runoff formation in the Krkonoše Mts in August 2002. Soil & Water Research 3 (Special Issue 1): 147–154.

LAPIN M. & FAŠKO P. 1997: Inter-sequential variability of atmospheric precipitation totals in Slovakia. Acta Meteorologica Universitatis Comenianae 25: 33–74.

TESAŘ M., ŠÍR M., PRAŽÁK J. & LICHNER Ľ. 2004b: Instability driven flow and runoff formation in a small catchment. Geologica Acta 2, 1: 147–156.

LICHNER Ľ., HOLKO L., ČIPÁKOVÁ A., ŠÍR M. & TESAŘ M. 2004: New devices and techniques for hydrological observation. In: WEBB B. (ed.), Proceedings of the British Hydrological Society 1: 447–452.

TROMP-VAN MEERVELD H. J. & MCDONNELL J. J. 2006a: Threshold relations in subsurface stormflow: 1. A 147-storm analysis of the Panola hillslope. Water Resources Research 42: W02410, DOI:10.1029/2004WR003778.

LIU Y., STEENHUIS T. S. & PARLANGE J.-Y. 1994: Formation and persistence of fingered flow fields in coarse grained soils under different moisture contents. Journal of Hydrology 159: 187–195.

TROMP-VAN MEERVELD H. J. & MCDONNELL J. J. 2006b: Threshold relations in subsurface stormflow: 2. The fill and spill hypothesis. Water Resources Research 42: W02411, DOI:10.1029/2004WR003800.

NOAA 2010: Flash Flood Early Warning System Reference Guide. University Corporation for Atmospheric Research. 204 pp.

WRB 1998: World reference base for soil resources. World Soil Resources Reports Vol. 84. FAO, Rome. 88 pp.

Water retention and runoff formation in the Krkonoše Mts

Recommend Documents