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From the end of nineties of the 20th century, intense hydrologic and geomorphologic research is taking place in the Slovene Istria. As a part of this research also studies on soil erosion were undertaken in the period from 2005 to 2008. The field measurements were undertaken on closed 1 m2 large erosion plots under three different land uses (on bare soils in an olive grove, on an overgrown meadow, in a forest), placed south of the Marezige village in the Rokava River basin. We show weekly measurements of surface erosion (interrill erosion) for the period of 13 months (the end of March 2005 – the end of April 2006), as well as monthly and seasonal averages together with selected linear statistical correlations between soil erosion and weather parameters. From May 2005 to April 2006 the interrill erosion on bare soils in an olive grove with an inclination of 5.5° amounted to 9013 g/m2 (90 t/ha) that corresponds to surface lowering rate of 8.5 mm/yr; on an overgrown meadow with an inclination of 9.4° it amounted to 168 g/m2 (1,68 t/ha) that corresponds to surface lowering rate of 0.16 mm/ /yr; and in a forest with an inclination of 7.8° it amounted to 391 g/m2 (3,91 t/ha) and in a forest with an inclination of 21.4° it amounted to 415 g/m2 (4,15 t/ha), respectively, that corresponds to surface lowering rate of 0.4 mm/yr. agensi, marsikje pospe{eno zaradi delovanja ~loveka (goloseki, ~ezmerna pa{a, nadelava, gradnja poti) in živali, ki je intenzivnej{e od nastajanja prsti ...« (KOMAC & ZORN, 2005; ZORN, 2008). Stanje na podro~ju raziskav erozije tal v Sloveniji najbolje ponazori trditev zapisana pri oceni izvajanja Konvencije Združenih narodov o degradaciji tal v Sloveniji (OCENA, ... 2005): »... Erozija tal je v Sloveniji relativno malo raziskana ...«. Podobno trditev najdemo tudi pri ^ARMANOVI, MIKO{U in PINTARJEVI (2007). Podatke o dosedanjih raziskavah so zbrali KOMAC in ZORN (2005, 2007), doi:10.5474/geologija.2009.022 222 Matija Zorn & Matjaž Miko{ ZORN in KOMAC (2005), HRVATIN in sodelavci (2006) ter ZORN (2008). Pregled ~lankov v reviji Geologija kaže na zapostavljenost tega podro~ja tudi v slovenski geologiji, ~eprav so tla v zadnjem desetletju postala predmet intenzivnih geolo{kih, predvsem geokemi~nih raziskav (npr. SAJN et al., 2000; SAJN, 2001; SAJN & GOSAR, 2007). Slovenska Istra oziroma podrobneje pore~je Dragonje je bila za obmo~je meritev izbrana, ker so tu od konca 20. stoletja potekale intenzivnej{e raziskave nekaterih hidrolo{kih in geomorfnih procesov (npr. GLOBEVNIK, 2001; PETKOV{EK, 2002; BIZJAK, 2003; SRAJ, 2003; STAUT, 2004; KEESSTRA, 2006; MIKO, 2006; TOL, 2006). Poleg teh smo se lahko navezali tudi na nekatere morfogenetske {tudije (npr. KOKOLE, 1956; MELIK, 1960; SIFRER, 1965; 1997; PLACER, 2005a; 2005b) in starej{a dela o erozijskih procesih (npr. JEŽ, 1956/57; PAULI~, 1971; WRABER, 1971; NATEK, 1990). Skupna zna~ilnost omenjenih del je, da so bile meritve erozijskih procesov redke (npr. PETKOV{EK, 2002; KEESSTRA, 2006). Pogostej{a je bila uporaba razli~nih erozijskih modelov (npr. PETKOV{EK, 2000), {e posebej za ugotavljanje erozije tal (npr. GLOBEVNIK, 2001; PETKOV{EK, 2002; STAUT, 2004; KEESSTRA, 2006; MIKO, 2006; STAUT & MIKO{, 2008). Da bi naredili korak naprej od modeliranja erozije tal, smo marca 2005 za~eli z njenimi meritvami. Meritve so potekale do vklju~no avgusta 2008 (ZORN, 2007a; 2007b; 2008; ZORN & PETAN, 2007, 2008). V ~lanku predstavljamo meritve prvih 13 mesecev raziskovalnega obdobja (konec marca 2005 – konec aprila 2006).

Steep bare rocky slopes that are badlands at the same time, are a morphogenetic particularity of the flysch part of the Istrian Peninsula. On them, microrelief forms are of a short life cycle, since erosion processes are fast. On the basis of measurements of sediment production in flysch rocks on four erosion plots in the Rokava watershed situated south of the village of Marezige, we show in this paper how fast these processes are. The annual sediment production in flysch rocks is on average around 80 kg/m2, which means that the slope retreat rate is about 35 mm/year. Furthermore, weekly measurements of sediment production in flysch rock for the period of 15 months (from February 2005 till April 2006) are shown, as well as weekly and seasonal averages. Linear statistical correlations between sediment production in flysch rocks and weather conditions are also presented.