Spatial and temporal heterogeneity of runoff and soil loss dynamics under simulated rainfall 25Szabó, J. et al. Hungarian Geographical Bulletin 64 (2015) (1) 25–34. Spatial and temporal heterogeneity of runoff and soil loss dynamics under simulated rainfall Judit S Z A B Ó1, Gergely J A K A B 2 and Boglárka S Z A B Ó3 1 Department of Environmental and Landscape Geography, Eötvös Loránd University, Faculty of Science. H-1117 Budapest, Pázmány Péter sétány 1/C. E-mail: szabojuditalexandra@gmail.com 2 Geographical Institute, Research Centre for Astronomy and Earth Sciences, HAS. Budapest, H-1112 Budapest, Budaörsi út 45. E-mail: jakabg@mtafk i.hu 3 Department of Nature Conservation and Landscape Ecology, Szent István University, Faculty of Agricultural and Environmental Sciences. H-2100, Gödöllő, Páter K. u. 1. E-mail: bogi87@gmail.com DOI: 10.15201/hungeobull.64.1.3 Hungarian Geographical Bulletin 64 2015 (1) 25–34. Abstract The factors aff ecting soil erosion processes are complex and various, comprises two phases: detachment and transport by water. Previous studies indicated that initial moisture content, slope and soil crusts are playing an important role in soil erosion. The primary objectives of this study were to examine the sediment concentration and aggregate size distribution of the washed sediment. Aims were also to create diff erent season specifi cally modelled situations in order to check runoff rates on bare soils under heavy rainfall. The experiments were conducted with a laboratory-scale rainfall simulator using a 1/2 HH 40 WSQ fulljet nozzle on eutric calcaric Cambisol loamic. Altogether, 72 soil loss samples were collected (6 separate precipitations, 3 time periods, 4 particle size fractions). The experiments indicated that the runoff rate was not increased by the presence of soil crusts, and even less sediment occurs on crusted surfaces. This sediment contained smaller fractions compared to recently tilled surface. The sediment concentration increased with the slope angle, but the run- off rates probably depend rather on the micro-morphology and initial moisture content of the surface. The main erosion process is the raindrop erosion after inland inundation and drought in gentle slopes, while the intermediate period of the precipitation is the most erosive. In general, the ratio of the macro aggregates in soil losses decrease and the ratio of the smaller fractions increase with the time during a precipitation event. Changing climate conditions are shown to have an eff ect on agricultural production through the temporal and spatial distribution of the erosion rates. Keywords: soil erosion, rainfall simulation, runoff , aggregate size Introduction The soil loss by erosion is a widespread prob- lem in agricultural areas. Soil erosion proc- esses are aff ected by complex and various fac- tors, including two phases: detachment and transport by water. A laboratory-scale rainfall simulator is an ideal tool for examining both phases of soil erosion on arable soils since most of the infl uential factors can be simulated and examined by its help. The advantages of the laboratory scale rainfall simulators are the Szabó, J. et al. Hungarian Geographical Bulletin 64 (2015) (1) 25–34.26 cial rock fragments during rain splash ero- sion. GÓmez, J.A., and Nearing, M.A. (2005) analysed the natural surface roughness while the eff ects of the impervious surface runoff were studied by Pappas, E.A. et al. (2008). Both provided diff erent points of view re- garding surface roughness. Mohammad, A. and Adam, M. (2010) concentrated on the ef- fect of vegetation and land use. However, the major problem with this kind of applications is that various simulators and methodologies exist. All the essential variables that indicate sediment dynamics are to be taken into con- sideration, especially sediment concentra- tions, sediment yield and transportability of soil particles (Defersha, M.B. and Melesse, A.M. ₍2012). Nearing, M.A. et al. (2005) modelled dif- ferent situations to present how the soil re- sponses to potential climate change. Among others Nearing, M.A. et al. (2005) pointed out on the climate change impact of runoff and erosion, as the increasing rainfall inten- sity and rainfall amount together “will have greater impact on runoff and erosion than changes in rainfall amount alone.” Recently, the meteorological conditions in Hungary got more and more inordinate. The probability of drought occurrence is estimated to increase; the wett est months are April and May while the driest are July and August (Bartholy, J. et al. 2014). Extreme rainfalls occur more often therefore agricultural areas will be potential- ly endangered by water erosion in a much wider range. This risk alternates during one year according to the diff erent seasons. The primary objectives of this study were to examine the sediment concentration and aggregate size distribution of the soil loss and to create diff erent season-specifi c mod- elled situations in order to check the runoff rates. Three approaches were in the focus of the experiments on bare soil under heavy rainfall: (1) Sedimentary crust formed after a pre- cipitation event (West, L.T. et al. 1992). The eff ect of this crust on sediment concentra- tion was examined in case of two diff erent slope steepnesses (5% and 12%) by applying followings: the eff ect of the soil heterogene- ity is negligible, easy to concentrate on one or two factors and this is a fast method (Grismer, M.E. 2010). According to Meyer, L.D. (1965) “The use of rainfall simulators generally pro- vides a more rapid, effi cient, controlled and adaptable tool than natural rainfall.” The first rainfall simulator in Hungary was designed by KazÓ, B. (1966) in order to study infi ltration, while Kerényi, A. (1986) concentrated on the role of initial erosion. Experiments were conducted to determine the erodibility (“factor K” in USLE equita- tion) of diff erent Hungarian soils using a fi eld scale rainfall simulator ₍Centeri, Cs. and Császár, A. 2003; Centeri, Cs. and Pataki, R. 2003; Jakab, G. and Szalai, Z. 2005; Kertész, Á. and Centeri, Cs. 2006; Centeri Cs. et al. 2011). Aggregates are groups of soil particles that are bound to each other. Their patt ern – soil structure – has an infl uence on the physical and chemical processes of soils. Aggregate stability is one of the most important proper- ties, which indicate soil resistivity against ex- ternal eff ects as raindrop impacted aggregate breakdown (Kerényi, A. 1986; Le Bissonnais, Y. et al. 1989). The aggregate breakdown process is also connected with crust forma- tion (West L.T. et al. 1992) and thus eff ects erosion rates. Erosion studies usually use the measure- ment of the sediment concentrations, runoff rates and aggregate stability in order to ex- amine the eff ect of the slope, initial moisture content, rainfall intensity, eff ect of the crust or the surface roughness on erosion rates (Jin, K. et al. 2008; Defersha, M.B. and Melesse, A.M. 2012). The literature on simulated soil erosion experiments suggests several approaches. Defersha, M.B. and Melesse, A.M. ₍2012) examined the eff ect of the initial moisture content and slope steepness on erosion, whereas Le Bissonnais,Y. et al. (1989) studied the aggregate breakdown mechanism and soil crusting on pre-wett ed and air-dry soils. Jomaa, S., et al. (2012) concentrated on initial moisture contents and on the eff ect of surfi - 27Szabó, J. et al. Hungarian Geographical Bulletin 64 (2015) (1) 25–34. two simulated rainfalls within following two days. (2) Two extreme soil moisture contents. The role of inland inundation and the drought were studied related to the changing climate conditions. (3) Periods of each precipitation were stud- ied beside the seasonal aspect. Aims were to compare the runoff dynamics and aggregate size distribution of the soil loss on diff erent surfaces. Rainfall simulation Three fundamental criteria are commonly considered in designing a rainfall simulator (Hall, M.J. 1970), namely, (1) the control of application rates in both time and space, (2) the reproduction of drop-size distribu- tions observed in diff erent intensities of natural rainfall at the corresponding application rates, (3) the reproduction of the terminal veloci- ties of drops in natural rainfall. Grismer, M.E. (2010) summarized the rainfall simulation methodology, the simulator types, the erosion models and the rainfall character- istics. Several authors reported many types of laboratory scale rainfall simulators those can be used for research (e.g. Le Bissonnais, Y. et al. 1989; GÓmez, J.A. and Nearing, M.A. 2005; Pappas, E.A. et al. 2008; Aksoy, H. et al. 2012; Defersha, M.B. and Melesse, A.M. 2012). According to Grismer, M. E (2010) the 80 per- cent of the simulators (both fi eld and labora- tory) are nozzle type simulators. In this study, a laboratory rainfall simula- tion procedure was developed and utilized to examine aggregate size distribution of the soil loss and the runoff rates during the pre- cipitation on diff erent surfaces, but using the same soil. Our laboratory scale rainfall simu- lator is situated in Eötvös Loránd University, Faculty of Science, Budapest. The fi rst stage of the simulator was designed by ZámbÓ and Weidinger (ZámbÓ, L. and Weidinger, T. 2006) (Photo 1). For the fi rst time, it had only an individ- ual (pin) drop-former system 9 m above the monolith. In these days 1/2 HH 40 WSQ ful- ljet nozzle, 1/2 HH 50 WSQ fulljet nozzle can be used, too. The soil sample fl ume is 0.5 m × 1.0 m × 0.2 m (0.1 m3) and its steepness is adjustable (0–40%). There are four taps on the bot- tom of the fl ume, so the leached water can be col- lected as well. The soft water from the plumbing runs through a pressure regulator system there- fore no water tank is needed during the simu- lations. Photo 1. The rainfall simulator: the rainfall simulator viewed from the front (a), drop-former system (b), the examined soil viewed from above with fall- ing droplets (c), and the satu- rated soil (d) Szabó, J. et al. Hungarian Geographical Bulletin 64 (2015) (1) 25–34.28 Methodology Rain simulation This paper presents data of six treatment com- binations: recently tilled (T) and crusty soil surface (C) on two diff erent slope steepness (5; 12), inland inundation (II) and drought (D) soil conditions on 2 percent slope steepness (Table 1). For each treatment the same 20 cm thick soil sample was packed into the fl ume overlaying a geotextile. 5T, 12T 2D treatments were applied on initially dry soil conditions, 5C, 12C treatments were applied on fi eld ca- pacity water content soil and 2II treatment was applied on the three weeks saturated soil. The distributed soil was taken in Ceglédbercel, Hungary (N47.249765°, E19.678761°, 150 m a.s.l.). The mean annual temperature in the studied area is 10.8 °C and the annual precipi- tation is around 600 mm (DÖvényi, Z. 2010). The eroded eutric calcaric Cambisol loamic has 18.8 percent of CaCO3, the total organic carbon (TOC) content is 1 percent, and the pH is 7.5. Drop forming nozzle system was chosen to examine the eff ect of intensive rainfall under diff erent seasonal situations. Later, the same nozzle system can be used during fi eld experi- ments in order to compare the results. The ex- periments were conducted in the laboratory using a 1/2 HH 40 WSQ fulljet nozzle which is widely used in rainfall simulation studies (Strauss, P. et al. 2000; Armstrong, Q. and Quinton, J.N. 2009). Since the cone basis of this nozzle was four times larger than the size of the monolith only one nozzle was applied. The simulated rainfall characteristics de- pend on the nozzle type used and the pres- sure applied. According to the measurements of Strauss, P. et al. (2000) the kinetic energy of the rainfall simulated by the nozzle 1/2 HH 40 WSQ is 17 kJ m-2 mm-1 at 20 kPa. This value would correspond to approximately 65 per- cent of the kinetic energy of natural rainfall with the intensity of 50 mm h-1. Figure 1 shows Table 1. Details of the six treatments Simu- lation code Slope steep- ness % Surface Time min’ sec” Energy kJ m-2 mm-1 CU % Median drop size mm Aim of the treatment 5T 5C 12T 12C 2II 2D 5 5 12 12 2 2 Recently tilled Crusty Recently tilled Crusty After inland inundation After drought simulation 42’11” 32’43’’ 33’34” 8’45” 22’25” 29’22” 17 17 17 17 17 17 98 97 94 97 93 96 1.95 1.95 1.95 1.95 1.95 1.95 Bare soils in autumn and spring Eff ect of the crust Bare soils in autumn and spring Eff ect of the crust Extreme situation (summer) Extreme situation (summer) Fig. 1. Spatial distribution of simulated rainfall in mm after 20 minutes precipitation. The average intensity is 80 mm/h. a = 26–28 mm; b = 28–30 mm; c = 30–32 mm; d = 32–34 mm 29Szabó, J. et al. Hungarian Geographical Bulletin 64 (2015) (1) 25–34. the spatial distribution of simulated rainfall in mm after 20 minutes precipitation. The aver- age intensity is 80 mm h-1. Simulated rainfall intensity was held constantly for these tests. The Christiansen’s uniformity coeffi cient (CU) (Christiansen, J.E. 1942) which determine the uniformity of a sprinkler system was over 90 percent in case of all the six simulations, hence, the rainfall can be considered both spa- tially and temporary uniform. Each runoff event was divided into three temporal phases, therefore the eroded sedi- ment was collected in three periods (I, II, III) at three litres of the runoff intervals during the precipitation. Aims were to detect the temporal changes in aggregate sizes. Each three litre runoff phase soil loss was collected through sieve series with the following open- ings: 1 mm, 250 μm and 50 μm to a bucket. Therefore, by measuring the mass of frac- tions, the scale of the diff erent aggregates is obtained directly. The capacity limitation of the sieves was equal to the sediment amount of three litres of water. During this study a (2%), b (5%) and c (12%) slope steepness were applied which represented: a) fl at plain where the inland inundation took place, b) the average steepness of the agricultural areas in Hungary, c) the suggested steepest slope in arable land areas. Altogether 72 sample were collected (6 treat- ments × 3 time periods × 4 aggregate size frac- tions). The samples were used to calculate sed- iment concentration. Four sample repetitions of the untreated soil were also separated by this sieve system in prior to the measurements using the wet sieving method of Kemper, D.W. and Rosenau, R.C. (1986) as a control. The time was recorded after every 1 litre col- lected runoff . In the experiment 12C only three litres of runoff were collected (one period of the precipitation was represented by one litre run- off ) because the high amount of the sediment on the sieves. In the experiment 12T the time and litre data had to be corrected subsequently because of sieve sealing. Weights of dried soil losses were recorded at the nearest 0.01 g. Results and discussion The changes of necessary time for 1 litre run- off are presented on Figure 2. There are two points in the zero line, the fi rst point repre- sents the time when runoff was started and the second means the time of surface pond- ing without any runoff . Runoff started after a twice longer period in case of 2D when the drought was simulated, because of the formation of big rifts according to the arid period, and because these needed to be in- fi lled fi rst. Shortest time was needed for the runoff in case of 2II, when the inland inun- dation was simulated. Runoff starts almost immediately, which means signifi cantly 10 minutes diff erences (one fourth of the total time) (Table 1). To compare the 5T-5C and 12T-12C cases, the runoff started earlier from the crusty sur- faces. This was due to the bigger initial mois- ture content on the crusty surfaces compared to the tilled surfaces. Three diff erent runoff periods are separated on Figure 2. As fi rst stage the curves are posi- tioned in the zero line, without any runoff yet. The curves are diff erent, because of the chang- ing runoff rates and thus infi ltration rates till the runoff of the third litre suspension. The ratio of the runoff and infi ltration is constant during the third period (after the runoff of the third litre). The curves turn straight, which means that runoff and infi ltration are in bal- ance. The equations on Figure 2 show the third runoff periods of the 5T, 5C and 2II, 2D treatments. The curves of the 5T and 5C have the same steepness, which means that crust evaluated this way is not characterized by any infl uences on runoff rates except the length of the time period before the runoff changed. The curves of 12T, 12 C, 2II and 2D treatments are steeper than 5T and 5C curves, therefore a higher infi ltration rate is presumed in the latt er cases. High runoff rate from 2 percent slope are assumed to be related to the degrad- ed soil structure, but more experiments are needed in order to prove this phenomenon. The results of 12T were corrected and at 12C the duration of the precipitation was too short. Szabó, J. et al. Hungarian Geographical Bulletin 64 (2015) (1) 25–34.30 By this means the observed results were not examined in more detail. Figure 3 represents the average sediment concentration increase with the slope angle. Runoff on steeper slopes contains greater amount of soil particles compared to gentle slopes. Runoff rates are not infl uenced by slope angles and thus do not infl uence the ve- locity of runoff . Defersha, M.B. and Melesse, A.M. (2012) got the same results in three dif- ferent soil types with two diff erent moisture contents and under three diff erent rainfall intensities. On the other hand, Fox, D.M. et al. (1997) reported contradicting results on the slope dependence of the infi ltration and crust formation on runoff rates. They assume that this contradiction may be connected to the diff erent micro-morphology of the surfaces. Table 2 summarizes the sediment concen- tration changes during the precipitation. The concentration of the sediment is higher at the tilled surface except the third period of the treatment 12C where the steep slope increased the concentration of the sediment, but more data is needed to determine the highest concentration which has eff ect on the mean values in Figure 3. During the pre- cipitation in case of 12T fourfold measure of the sediment was washed down compared to the case of the 5T in the fi rst period. In the second period, the diff erences decreased threefold and to the end of the precipitation increased a litt le bit more than fourfold again. During the three periods of the precipitation, the rates in case of 5C and 12C treatments are bigger, 5.0, 3.5 and 5.0-fold respectively. Almost the same density sediment was washed down from the surfaces of 2II and 2D precipitation and there was no signifi cant diff erence between the periods of the pre- cipitation. It was one order less dense than the others (Table 2, Figure 3), therefore, we can state that extreme initial moisture con- tent has no eff ect on sediment concentration changes. Wett ing and drying cycles have in- fl uence on the soil structure (Bodner, G. et Fig. 2. The changes of necessary time for 1 litre runoff . There are two points in the zero line. The fi rst point represents the time of surface ponding. There is no any runoff yet. Second point means the time when runoff has started. The equations refer to the 5T, 5C and 2II, 2D treatments after the third litre of runoff . 31Szabó, J. et al. Hungarian Geographical Bulletin 64 (2015) (1) 25–34. al. 2013) therefore erosion aff ects diff erently in extreme moisture content soils. The treat- ment of 2D and 2II had the lowest soil con- tent in the runoff because the structure of the soil and aggregate stability was very weak. Aggregates were easy to detach to elemen- tary particles, and due to the gentle slope, the runoff was able to transport only fi ner parti- cles. Initial erosion and raindrop impact are supposed to have more signifi cant infl uence on particle redistribution in these two cases. The lowest sediment concentration and high- est runoff rate were observed for 2B. Areas covered by inundation are generally fl at or have only gentle slopes hence the main risk there is not the runoff , rather the struc- ture degradation. The fraction content and sediment concentration are almost the same due to the degraded structure. The sediment concentration trend is the same in all cases during the precipitation. The second period is the most erodible, except the 12C when the sediment concentration increased (Table 2). Table 3 summarizes the results of all (72) soil loss samples and the 4 sample sets of the origi- nal soil. Washed sediment lacked macro ag- gregates larger than 1 mm. On the average, the diff erence is 38 percent between the ratio of the aggregates >1 mm in original soil sample and the soil loss. This fraction is underrepresented Fig. 3. The sediment concentrations and runoff rates of the six treatments Table 2. Sediment concentration changes during the precipitation in the six treatments Periods 5T 5C 12T 12C 2II 2D g l-1 Period I Period II Period III Whole precipitation 10.95 15.19 10.69 12.28 7.46 12.09 11.70 10.42 43.88 49.93 45.79 46.26 35.19 43.00 64.03 47.41 5.89 6.16 6.29 6.11 6.65 6.16 6.26 6.35 Szabó, J. et al. Hungarian Geographical Bulletin 64 (2015) (1) 25–34.32 in the sediment with less than 1 percent except for 12C. During the rain, there were no trends present, but the mass of the soil loss in this fraction was under 1 g (therefore the dynam- ics were not relevant). The lack of this fraction was probably connected to the raindrop impact and partly to macro aggregates broke down to micro aggregates (50–250 μm) and elementary particles (<50 μm) due to slaking (as it was also reported by Le Bissonnais, Y. 1996). Generally, the rate of the soil loss of recent- ly tilled surfaces (5T and 12T) was larger in the 250–1,000 μm fraction than in the soil loss of crusty surfaces (5C and 12C). The propor- tion of this fraction was also larger at 12 per- cent slope steepness with the exception of the I. period of 5T when this ratio is the largest. The proportion of 250–1,000 μm was under 10 percent in case of 2II and 2D. The fraction of 50–250 μm showed the larg- est proportions in the soil loss compared to the original soil sample. The same trend was presented in the 250–1,000 μm fraction, where the tilled surface and the slope in- creased the proportion of this fraction (with the exception of the I. period of 5T, where the dominant fraction is the 250–1,000 μm). Treatment 2II and 2D showed decreasing trend during the precipitation. Soil loss was larger than in the case of the orig- inal soil, concerning the fraction of <50 μm at all proportions. The largest ratio was found in treat- ment 2II, whilst the last period of the precipita- tion. This fraction was characteristic of treatment 2II and 2D has with over 50 percent rate. To conclude, the runoff was faster from crusty or wett er surfaces (5C, 12C, 2II), how- ever, larger aggregates were eroded from re- cently tilled surfaces (5T, 12T). The runoff of 2D started late but it was fast. The aggregate size distribution changed in the eroded sedi- ment, which depended on the time frame of the treatment. Conclusion Laboratory scale rainfall simulator was used to examine soil erosion and runoff under six diff erent conditions represented by diff erent seasonal situations. Our results showed that the same soil sample under the same precipi- tation was eroded totally diff erent. Crusting had no defi nite role in infi ltration mitigation; moreover, we measured ambiguous data re- garding soil loss reduction. In general, the ratio of the macro aggregates decreased and the ratio of the micro aggre- Table 3. The aggregate size distribution results of all the 72 sediment samples, and the 4 sample of the original soil Size, μm Untreated soil 5T 5C 12T 12C 2II 2D % Period I >50 50–250 250–1,000 1,000< 4.81 24.63 32.00 38.57 32.56 19.84 46.96 0.64 29.59 47.88 22.49 0.04 14.08 52.50 32.77 0.66 36.54 29.87 31.74 1.85 52.70 43.07 3.93 0.29 70.16 19.91 9.63 0.30 Period II >50 50–250 250–1,000 1,000< 4.81 24.63 32.00 38.57 29.43 44.58 25.81 0.18 51.12 35.13 13.53 0.22 12.46 49.22 37.52 0.79 33.86 36.72 28.26 1.16 79.88 14.01 5.73 0.38 72.87 17.65 9.31 0.16 Period III >50 50–250 250–1,000 1,000< 4.81 24.63 32.00 38.57 38.01 42.75 18.64 0.61 49.97 37.69 12.19 0.14 13.30 49.91 35.96 0.84 28.99 40.93 28.44 1.64 80.06 13.47 6.10 0.37 72.38 18.79 8.62 0.21 33Szabó, J. et al. Hungarian Geographical Bulletin 64 (2015) (1) 25–34. gates and clay fraction increased in the sedi- ment during the precipitation. Larger amount of sediment was transported from steeper slopes by runoff , but larger aggregates were washed down from the tilled surface. The most erodible fractions play an important role in nutrient supply of agricultural areas thus the erosion protection is relevant. Changing climate conditions have even more eff ect on agricultural production through the temporal and spatial distribution of the erosion rates. It is necessary to understand the erosion proc- esses under diff erent conditions. The next stage of our research is to perform more experiments at the laboratory by using other soil samples and to compare and verify the results live on the fi eld. Further studies are planned concerning the elementary particles of the aggregate fraction, the organic matt er content and the clay mineral composition of the sediment. Future aims are to fi nd the main reason of surfi cial variability, i.e. to detect the diff erences among the seasonal erosion char- acteristics under heavy rainfall situations. R E F E R E N C E S Aksoy, H., Erdem Unal, N., Cokgor, S., Gediklia, A., Yoonb, J., Kocaa, K., Incia, S.B. and Erisc, E. 2012. A rainfall simulator for laboratory-scale assessment of rainfall-runoff -sediment transport processes over a two-dimensional fl ume. Catena 98. 63–72. Armstrong, Q. and Quinton, J.N. 2009. Pumped rainfall simulators: the impact of rain pulses on sediment concentration and size. Earth Surface Processes and Landforms 34. (9): 1310–1314. Bartholy, J., Pongrácz, R. and Pieczka, I. 2014. How the climate will change in this century? Hungarian Geographical Bulletin 63. (1): 55–67. Bodner, G., Scholl P. and Kaul, H.P. 2013. Field quantifi cation of wett ing–drying cycles to predict temporal changes of soil pore size distribution. Soil and Tillage Research 133. 1–9. Centeri, Cs. and Császár, A. ₂₀₀₃. A talajképződés és az erózió által kiváltott talajpusztulás kapcsolata a Tihanyi-félsziget példáján (The connection of soil formation and erosion induced soil loss in the Tihany Peninsula). Tájökológiai Lapok 1. (1): 81–85. Centeri, Cs. and Pataki, R. 2003. Hazai talajerodál- hatósági értékek meghatározásának fontossága a talajveszteség tolerancia értékek tükrében (Impor- tance of determining Hungarian soil erodibility values in connection with the soil loss tolerance values). Tájökológiai Lapok 1. (2): 181–192. Centeri, Cs., Jakab, G., Szalai, Z., Madarász, B., Sisák, I., Csepinszky, B. and BírÓ, Zs. 2011. Rainfall simulation studies in Hungary. In Soil Erosion: Causes, Processes and Eff ects. Ed.: Fournier, A.J. New York, NOVA Science Publisher, 177–217. Christiansen, J.E. 1942. Irrigation by Sprinkler. Agriculture Experimental Station Bulletin 37. 1–124. Defersha, M.B. and Melesse, A.M. 2012. Eff ect of rainfall intensity, slope and antecedent moisture content on sediment concentration and sediment enrichment ratio. Catena 90. 47–52. DÖvényi, Z. (ed.) 2010. Magyarország kistájainak katasztere (Cadastre of natural micro-regions of Hungary). 2. átdolgozott és bővített kiadás. Budapest, MTA Földrajztudományi Kutatóintézet, 876 p. Fox, D.M., Bryan, R.B. and Price, A.G. 1997. The in- fl uence of slope angle on fi nal infi ltration rate for interrill conditions. Geoderma 80. (1–2): 181–194. GÓmez, J.A. and Nearing, M.A. 2005. Runoff and sedi- ment losses from rough and smooth soil surfaces in a laboratory experiment. Catena 59. 253–266. Grismer, M.E. 2010. Rainfall Simulation Studies – A Review of Designs, Performance and Erosion Measurement Variability. TSC Rainsim workshop. 110 p. Hall, M. J. 1970. A critique of methods of simulating rainfall. Water Resources Research 6. (4): 1104–1113. Jakab, G. and Szalai, Z. 2005. Barnaföld erózióérzé- kenységének vizsgálata esőztetéssel a Tetves-patak vízgyűjtőjén (Brown soill erodibility measurements in the Tetves Stream catchment using rainfall simu- lator). Tájökológiai Lapok 3. (1): 177–189. Jin, K., Cornelis, W.M., Gabriels, D., Schiettecatte, W., De Neve, S., Lu, J., Buysse, T., Wu, H., Cai, D., Jin, J. and Harmann, R. 2008. Soil management eff ects on runoff and soil loss from fi eld rainfall simulation. Catena 75. (2): 191–199. Jomaa, S., Barry, D.A., Brovelli, A., Heng, B.C.P., Sander, G.C., Parlange, J.-Y. and Rose, C.W. 2012. Rain splash soil erosion estimation in the presence of rock fragments. Catena 92. 38–48. KazÓ, B. 1966. A talajok vízgazdálkodási tulajdon- ságainak meghatározása mesterséges esőztető készülékkel (Assessment of water management properties of soils with rainfall simulator device). Agrokémia és Talajtan 15. (2): 239–252. Kemper, D.W. and Rosenau, R.C. (1986) Aggregate sta- bility and aggregate size distribution. In: Klute, A. (Ed.), Methods of Soil Analysis Part 1. ASA-SSSA, Madison, WI, 425–442. Kerényi, A. 1986. Az iniciális erózió laboratóriumi vizsgálata homokon és szerkezetes talajokon (Laboratory simulation study on the initial erosion of sand and soils with well developed structure). Agrokémia és Talajtan 35. 18–38. Kertész, Á. and Centeri, Cs. ₂₀₀₆. Hungary. In Soil erosion in Europe. Eds. Boardman, J. and Poesen, J. Chichester, John Wiley & Sons Ltd. 139–154. Szabó, J. et al. Hungarian Geographical Bulletin 64 (2015) (1) 25–34.34 Le Bissonnais, Y. 1996. Aggregate stability and asses- sment of soil crustability and erodibility: I. Theory and methodology. European Journal of Soil Science 47. 425–437. Le Bissonnais, Y., Bruand, A. and Jamagne, M. 1989. Laboratory experimental study of soil crusting: relation between aggregate breakdown mechanism and crust structure. Catena 16. 377–392. Meyer, L.D. 1965. Simulator of rainfall for soil erosion research. Transactions of the ASAE 8. (1): 63–65. Mohammad, A.G. and Adam, M.A. 2010. The impact of vegetative cover type on runoff and soil erosion under diff erent land uses. Catena 81. 97–103. Nearing, M.A., Jetten, V., Baffaut, C., Cerdan, O., Couturier, A., Hernandez, M., Le Bissonnais, Y., Nichols, M.H., Nunes, J.P., Renschler, C.S., Souchére, V. and Van Oost, K. 2005. Modelling response of soil erosion and runoff to changes in precipitation and cover. Catena 61. (2): 131–154. Pappas, E.A., Smith, D.R., Huang, C.W.D. and Shuster Bonta, J.V. 2008. Impervious surface impacts to runoff and sediment discharge under laboratory rainfall simulation. Catena 72. (1): 146–152. Strauss, P., Pitty, J., Pfeffer, M. and Mentler, A. 2000. Rainfall simulation for outdoor experiments. In Current Research Methods to Assess the Environmental Fate of Pesticides. Eds. Jamet, P. and Cornejo, J. Idaho Falls, USA, INRA Editions, 329–333. West, L.T., Chiang, S.C. and Norton, L.D. 1992. The morphology of surface crusts. In Soil Crusting: Chemical and Physical Processes. Advanced Soil Science. Eds Sumner, M.E. and Stewart, B.A. Boca Raton, Lewis Publisher, 73–92. ZámbÓ L. Weidinger T. 2006. Karsztkorróziós talaj- hatás néhány tényezőjének vizsgálata esőszimu- lációs kísérletek alapján (Investigations of karst corrosional soil eff ects based on rainfall simulator experiment). In Táj, környezet és társadalom. Ünnepi tanulmányok Keveiné Bárány Ilona professzor asszony tiszteletére. Eds.: Kiss, A., MezŐsi, G. and SÜmeghy, Z. 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