Water-induced soil erosion and shallow landslides interact with each other and need to be studied in an integrated approach to understand hillslope sediment yields. The principal aim of this thesis was to study and model soil erosion and shallow landslides in an integrated way. The thesis presents results from laboratory and catchment-scale studies and modelling. A laboratory flume under a rainfall simulator was used for shallow landslide and soil erosion experiments using sandy and silty loess soils. In the experiments, landslide initiation, retrogressions and slip surface depths were measured and monitored directly or by using video camera recordings. Sediment and runoff were collected from the flume outlet every minute during landslides and every 10 minutes before and after landslides. Changes in the soil slope, after landslides, were recorded. Initially, six experiments including two repetitions were conducted using sandy soils at a 30º and 10º compound slope configuration, but with different soil profile depths. The experimental results showed that total and landslide-driven sediment yields were affected by the original soil profile depth; the greater the depth, the higher the sediment yield. Later, twelve other experiments were conducted on different slopes using silty loess soils. The experimental observations were used to validate an integrated modelling approach which includes WEPP for runoff and soil erosion modelling, a slope stability model for simulating shallow landslides, and a simple soil redistribution model for runout distance prediction. The model predictions were in good alignment with the observations. In all (sandy and silty loess) experiments, peak sediment discharges were related to the landslide events, proximity to the outlet and landslide volume. The post-failure soil erosion rate decreased as a function of changes in the slope profile. The GeoWEPP-SLIP modelling approach was proposed for catchment-scale modelling. The approach simulates soil erosion using the Hillslope and Flowpath methods in WEPP, predicts shallow landslides using a slope stability model coupled with the WEPP’s hillslope hydrology and finally uses a simple rule-based soil redistribution model to predict runout distance and post-failure topography. A case study application of the model to the Bowenvale research catchment (300 ha) showed that the model predictions were in good agreement with the observed values. However, the Hillslope method over-predicted the outlet sediment yield due to the computational weighting involved in the method. The Hillslope method predicted consistent values of sediment yield and soil erosion regardless to the changes in topography and land-cover in the post-failure scenarios. The Flowpath method, on the other hand, predicted higher values of sediment yield in the post-failure vegetation removal scenario. The effects of DEM resolution on the approach were evaluated using four different resolutions. Statistical analyses for all methods and resolutions were performed by comparing the predicted versus measured runoff and sediment yield from the catchment outlet and the spatial distribution of shallow landslides. Results showed that changes in resolution did not significantly alter the sediment yield and runoff between the pre- and post-failure scenarios at the catchment outlet using the Hillslope method. However, the Flowpath method predicted higher hillslope sediment yields at a coarser resolution level. Similarly, larger landslide areas and volumes were predicted for coarser resolutions whereas deposition volume decreased with the increase in grid-cell size due to changes in slope and flowpath distributions. The research conducted in the laboratory and catchment presented in this thesis helped understand the interactions between shallow landslides and soil erosion in an integrated approach.

<p>Erozija predstavlja vrlo složen fizički proces u kome pod dejstvom atmosferskih sila nastaju&nbsp;destruktivne promene na povr&scaron;inskom sloju zemlji&scaron;ta. Kada je osnovni agens pokretanja&nbsp;čestica zemlji&scaron;ta vetar, govori se o eroziji vetrom ili eolskoj eroziji. Eolska erozija je&nbsp;specifičan proces koji se odvija u izrazito složenim okolnostima uzajamnog delovanja&nbsp;brojnih prirodnih i antropogenih faktora uglavnom stohastičkog karaktera, zbog čega je&nbsp;njeno istraživanje kompleksan naučno-istraživački problem.</p><p>Osnovni cilj sprovedenih istraživanja je bio da se na izabranim lokalitetima Deliblatske&nbsp;pe&scaron;čare, najvećeg i najznačajnijeg područja takve vrste u Evropi, uspostavi praćenje stanja&nbsp;procesa eolske erozije, odnosno neposrednim, sistematskim merenjima u terenskim&nbsp;uslovima ustanove količine eolskog nanosa &ndash; pronos nanosa, odrede dominantni pravci&nbsp;njegovog kretanja, defini&scaron;e njegova unutargodi&scaron;nja raspodela i utvrdi efekat vegetacije na&nbsp;smanjenje intenziteta eolske erozije. U toku četvorogodi&scaron;njeg perioda su po prvi put na&nbsp;ovim prostorima, na istom lokalitetu, sprovedena uporedna istraživanja eolske erozije&nbsp;primenom mehaničkih hvatača nanosa i metoda zasnovanih na praćenju aktivnosti&nbsp;radionuklida ve&scaron;tačkog porekla 137Cs u zemlji&scaron;tu, čije količine služe da se posebnim&nbsp;teorijskim modelima pretvore u gubitke zemlji&scaron;ta.</p><p>Praćenje procesa eolske erozije je vr&scaron;eno od 2006. do 2009. godine na lokalitetu Cvjićev vis,&nbsp;koji je izabran kao karakterističan, jer je pored centralne pozicije na Deliblatskoj pe&scaron;čari,&nbsp;obrađivani povr&scaron;inski sloj zemlji&scaron;ta bio bez za&scaron;tite od vetra. Paralelno sa ovim merenjima,&nbsp;na lokalitetu Dragićev hat &ndash; rasadnik, praćenje procesa eolske erozije vr&scaron;eno je na dva&nbsp;merna mesta u periodu od maja 2006. godine do aprila 2007. godine u uslovima postojanja&nbsp;za&scaron;titne uloge vegetacionog pokrivača i/ili vegetacionog pojasa. Merenje intenziteta eolske&nbsp;erozije je realizovano statičnim hvatačima nanosa tipa deflametar (dimanzija ulaznog&nbsp;otvora 10 x 10 cm) orijentisanih prema određenim pravacima (N, NE, E, SE, S, SW, W, NW) da bi potpuno definisali procese eolske erozije u vektorskom smislu. Kvantifikacija eolskog nanosa statičnim hvatačima stalno usmerenim prema određenim pravcima duvanja vetrova, omogućila je da se posebno evidentiraju i razlikuju &bdquo;sumarna&rdquo; produkcija eolskog nanosa (aritmetički zbir zahvaćenih količina nanosa iz svih hvatača) i &bdquo;rezultujuća&rdquo; količina eolskog nanosa (vektorski zbir), jer te veličine određuju pored ukupno pokrenute količine eolskog nanosa (produkcija nanosa) i delove nanosa koji se transportuju van granica&nbsp;erozionog polja (gubitak zemlji&scaron;ta), generalni pravac i smer njegovog kretanja.</p><p>Merenja eolske erozije na lokalitetu Cvijićev vis za period 2006-2009. godine su ukazala na&nbsp;značajne procese eolske erozije koji su definisani srednjim godi&scaron;njim pronosom nanosa od&nbsp;4,48 kg m-1. Ustanovljeno je da su ukupno zahvaćene količine nanosa na 8 hvatača bile &Sigma; =&nbsp;25,94, 20,92, 52,98 i 43,47 kg m-1 god-1, a pronosi nanosa &Sigma;&#39; (&Sigma;/8) = 3,24, 2,61, 6,62 i 5,43 kg&nbsp;m-1 god-1 u 2006., 2007., 2008. i 2009. godini respektivno.</p><p>Pronosi nanosa za period od maja 2006. do aprila 2007. godine su pokazali da je na<br />lokalitetu Cvijićev vis koga karakteri&scaron;u neobraslost i otvorenost povr&scaron;ine zabeležen najveći&nbsp;intenzitet eolske erozije na godi&scaron;njem nivou koji je 4 puta veći u odnosu na lokalitet&nbsp;Dragićev hat &ndash; rasadnik I koga karakteri&scaron;u neobraslost i za&scaron;tićenost povr&scaron;ine i 30,2 puta veći&nbsp;u odnosu na Dragićev hat &ndash; rasadnik II koga karakteri&scaron;u obraslost i za&scaron;tićenost zemlji&scaron;ta. Na&nbsp;lokalitetu Dragićev hat &ndash; rasadnik I intenzitet eolske erozije na godi&scaron;njem nivou je 7,5 puta&nbsp;veći od onog na lokalitetu Dragićev hat &ndash; rasadnik II.</p><p>Gubici zemlji&scaron;ta izraženi preko rezultujućih mesečnih pronosa nanosa (vektorski zbir)<br />iznosili su 5,13, 2,04, 4,31 i 11,94 kg m-1 u 2006., 2007., 2008. i 2009. godini respektivno, a&nbsp;procentualni udeo godi&scaron;njih gubitaka zemlji&scaron;ta u odnosu na ukupnu produkciju nanosa&nbsp;(aritmetički zbir) se kretao od 8,1% do 27,5. Rezultujući pravac kretanja eolskog nanosa u&nbsp;toku perioda istraživanja bio je jugoistok - severozapad (SE-NW) pod uticajem dominantnog&nbsp;jugoistočng vetra &bdquo;Ko&scaron;ava&rdquo;.</p><p>Iako se najpouzdanije determinisanje eolske erozije i njenih efekata postiže na osnovu&nbsp;neposrednih sistematskih merenja u realnim terenskim uslovima, počev od kraja pro&scaron;log&nbsp;veka se sve vi&scaron;e primenuju i metode praćenja radionuklida iz radioaktivnih padavina,&nbsp;posebno 137Cs, u cilju procene gubitaka zemlji&scaron;ta i prostornog rasporeda eolskog nanosa.</p><p>Ukupan broj uzetih uzoraka za metodu praćenja količina 137Cs je iznosio 149, od kojih je bilo&nbsp;9 inicijalnih uzoraka (3 profila po 3 uzorka), 14 osnovnih uzoraka (2 profila po 7 uzoraka), 32&nbsp;ostala uzorka (8 profila po 4 uzorka), 36 referentnih uzoraka (9 profila po 4 uzorka) i 58&nbsp;uzoraka uzetih zrakasto po određenim pravcima (N, NE, E, SE, S, SW, W, NW).</p><p>Osnovni uzorak na neobrađenom zemlji&scaron;tu sa detektovanom količinom 137Cs od 10.603,57&nbsp;Bq m-2 predstavlja uporednu vrednost, tj. lokalni padavinski ulaz 137Cs za modele&nbsp;pretvaranja količina 137Cs u količine izgubljenog zemlji&scaron;ta. Ovaj uzorak odslikava sredinu na&nbsp;kojoj su sprovedena istraživanja i predstavlja uporednu vrednost koja može korektno da&nbsp;defini&scaron;e procese eolske erozije.</p><p>Za pretvaranje izmerenih količina 137Cs u količine izgubljenog zemlji&scaron;ta po modelima&nbsp;Walling-a kori&scaron;ćen je najjednostavniji proporcionalni model (PM) za obrađena zemlji&scaron;ta, a&nbsp;najprimenjeniji model profilne distribucije (PDM) za neobrađena zemlji&scaron;ta u okviru najnovije verzije PC-kompatibilnog softverskog paketa u Microsoft Excel Add-Ins varijanti. Modelom profilne distribucije (PDM) za sve uzorake uzete na eksperimentalnom području dobijeni su prosečni gubici zemlji&scaron;ta od 207,06 t ha-1 god-1 i 2,10 cm. Model Basher &amp; Webb je dao prosečne gubitke zemlji&scaron;ta od 212,18 t ha-1 god-1 i 2,09 cm. Gubici zemlji&scaron;ta dobijeni modelima pretvaranja količina 137Cs u količine izgubljenog zemlji&scaron;ta ukazuju na značajne procese eolske erozije definisane jakom i ekscesivnom eolskom erozijom.</p><p>Za 58 uzoraka zemlji&scaron;ta uzetih na tačkama raspoređenih zrakasto po određenim pravcima&nbsp;(N, NE, E, SE, S, SW, W, NW), pored koncentracija i količina 137Cs i 210Pbex, određene su&nbsp;prostorne koordinate X i Y i nadmorske visine uzetih uzoraka. Prostorne distribucije&nbsp;koncentracija 137Cs i 210Pbex izražene su izolinijama, a kreiranani su i 3D prikazi u procentima&nbsp;odstupanja 137Cs i 210Pbex od lokalnog padavinskog ulaza 137Cs i 210Pbex. U oba slučaja je&nbsp;primetan dominantan uticaj pravca jugoistok - severozapad (SE-NW), odnosno jugoistočnog&nbsp;vetra &bdquo;Ko&scaron;ava&rdquo;.</p><p>Komparativna analiza ovih metoda je ukazala na validnost u kvantifikaciji procesa eolske&nbsp;erozije i mogućnost njihove primene u budućnosti, a dobijeni rezultati produkcije eolskog&nbsp;nanosa i gubitaka zemlji&scaron;ta su dali doprinos oceni stanja degradacije zemlji&scaron;ta i ugroženosti Deliblatske pe&scaron;čare.&nbsp;</p><p>&nbsp;</p> / <p>Erosion is a very complex physical process which, under the impact of atmospheric forces,&nbsp;creates destructive changes on the soil surface layer. In case the primary agent of particle&nbsp;movement is wind, we talk about wind or aeolian erosion. Aeolian erosion is a specific&nbsp;process which occurs in extremely complex situations of mutual interaction of numerous&nbsp;natural and anthropogenic factors of mainly stochastic properties making its research a&nbsp;complex scientific-research problem.</p><p>The main goal of conducted research was to monitor the process of aeolian erosion at the&nbsp;chosen localities of Deliblato Sands, the largest and the most important area of the kind in&nbsp;Europe. In other words, the goal is to determine the quantities of aeolian sediment &ndash;&nbsp;sediment transport by direct systematic measurements in field conditions, determine&nbsp;dominant direction of sediment transport, define its annual distribution and determine the&nbsp;effect of vegetation on reducing the intensity of aeolian erosion. During a four-year period,&nbsp;for the first time in this area, i.e. at the same locality, a comparative research of aeolian&nbsp;erosion have been conducted using the mechanical sediment trap and activities based on&nbsp;137Cs radioisotope tracing technique for estimating soil losses using special theoretical&nbsp;models.</p><p>The monitoring of aeolian erosion processes was conducted during the period 2006 &ndash; 2009&nbsp;at Cvijićev vis which was chosen as a typical locality since it was, apart from the central&nbsp;position on Deliblato Sands, a cultivated surface without any wind protection. Alongside&nbsp;with these measurements, at Dragićev hat &ndash; nursery garden, the monitoring of aeolian&nbsp;erosion was conducted on two measurement points during the period May 2006 &ndash; April&nbsp;2007 in areas with the protective vegetative covers and/or vegetative belts. Aeolian erosion&nbsp;intensity measurement was performed by static sediment traps of the type &ldquo;deflametre&rdquo;&nbsp;(dimension of entry opening 10 x 10 cm) oriented on certain directions (N, NE, E, SE, S, SW,&nbsp;W, NW) in order to define the aeolian erosion processes in vector terms. The quantification&nbsp;of aeolian sediment using static traps constantly facing certain wind blowing directions enabled to log and differentiate &ldquo;summary&rdquo; yield of aeolian sediment (arithmetic sum of all sediment quantities from all traps) and &ldquo;resulting&rdquo; quantity of aeolian sediment (vector sum), since those quantities determine not only the entire amount of transported aeolian sediment (sediment yield) but also the sediment transported outside the areas of erosion field (soil loss), bur also the general direction of its transport.</p><p>Aeolian erosion measurement on Cvijićev vis for the period 2006 &ndash; 2009 indicated the<br />significant aeolian erosion processes which were defined by medium annual ediment<br />transport of 4.48 kg m-1. It has been determined that the total quantities of moved<br />sediment were 25.94, 20.92, 52.98 and 43.47 kg m-1 year-1, and sediment transport 3.24,&nbsp;2.61, 6.62 and 5.43 kg m-1 year-1 in 2006, 2007, 2008 and 2009 respectively.</p><p>Sediment transport for the period May 2006 &ndash; April 2007 showed that on Cvijićev vis which&nbsp;is characterized by bareness and openness there was the biggest aeolian erosion &ndash; four&nbsp;times bigger compared to Dragićev hat &ndash; nursery garden I characterized by bareness and&nbsp;protectiveness and 30.2 times bigger compared to Dragićev hat &ndash; nursery garden II&nbsp;characterized by overgrown condition and protectiveness of erosive field. At the locality&nbsp;Dragićev hat &ndash; nursery garden I the aeolian erosion was recorded 7.5 times bigger&nbsp;compared to the one recorded on Dragićev hat &ndash; nursery garden II.</p><p>Soil loses expressed through the resulting monthly sediment transport (vector sum)<br />equalled 5.13, 2.04, 4.31 and 11.94 kg m-1 in 2006, 2007, 2008 and 2009 respectively, and&nbsp;the percentage share of annual soil losses compared to total sediment yield (arithmetical&nbsp;sum) varied between 8.1% and 27.5%. The resulting aeolian sediment movement direction&nbsp;was SE-NW under the influence of the dominant southeast wind &ldquo;Koshava&rdquo;.</p><p>Even though the most reliable determination of aeolian erosion and its effects is based on&nbsp;direct systematic measurements in real time conditions in the field, starting from the end&nbsp;of the last century the methods of tracking radionuclide from radioactive precipitation,&nbsp;especially 137Cs, for the purposes of estimating the soil loss and spatial distribution of&nbsp;aeolian sediment, have been used increasingly.</p><p>The total number of samples taken for the method of monitoring the quantity of 137Cs was&nbsp;149, 9 of which were initial samples (3 profiles with 3 samples each), 14 main samples (2&nbsp;profiles with 7 samples each), 32 remaining samples (8 profiles with 4 samples each), 36&nbsp;reference samples (9 profiles with 4 samples each) and 58 samples taken radially on certain&nbsp;directions (N, NE, E, SE, S, SW, W, NW).</p><p>The main sample taken from the uncultivated land with the detected quantity of 137Cs of&nbsp;10,603.57 Bq m-2 represents the comparative value, i.e. local precipitation input of 137Cs for&nbsp;the models of 137Cs quantities conversion into the quantities of lost soil. This sample depicts&nbsp;the area where the research was conducted and represents the comparative value which&nbsp;can properly define the aeolian erosion processes.</p><p>For converting the measured quantities of 137Cs into the quantities of lost soil using Walling&nbsp;model the simplest proportional model (PM) for cultivated land was used and the most&nbsp;appropriate profile distribution model (PDM) for uncultivated soil with the newest version&nbsp;of PC compatible software package in Microsoft Excel Add-Ins. Using the profile distribution model (PDM) on all samples taken from the experimental area the quantities of average soil loss obtained were 207.06 t ha-1 year-1 and 2.10 cm. Basher &amp; Webb model gave the average soil loss of 212.18 t ha-1 year-1 and 2.09 cm. Soil loss calculated using the conversion of 137Cs quantities into the soil loss quantities indicate the significant aeolian processes defined by strong and excessive aeolian erosion.</p><p>For 58 soil samples taken from areas radially distributed on certain directions (N, NE, E, SE,&nbsp;S, SW, W, NW), apart from 137Cs and 210Pbex concentrations and quantities, spatial&nbsp;coordinates X and Y were determined as well as the altitude of taken samples. Spatial&nbsp;distribution of 137Cs and 210Pbex quantities are represented by isolines, and also 3D&nbsp;demonstrations were created showing the percentage of deviation of 137Cs and 210Pbex from&nbsp;the local precipitation input of 137Cs and 210Pbex. In both cases, the dominant direction SENW&nbsp;was noticeable, i.e. the southeast wind &ldquo;Koshava&rdquo;.</p><p>The comparative analysis of these methods indicated the validity in the quantification of&nbsp;aeolian erosion process and the possibility of its application in the future and the obtained&nbsp;results of aeolian sediment yield and soil loss contributed to determining the state of soil&nbsp;degradation and vulnerability of Deliblato Sands.</p>