Dripping rainfall simulators are important instruments in soil research. However, a large number of non-standardized simulators have been developed, making it difficult to combine and compare the results of different studies in which they were used. To overcome this problem, it is necessary to become familiar with the design and performances of the current rainfall simulators. A search has been conducted for scientific papers describing dripping rainfall simulators (DRS) and papers that are thematically related to the soil research using DRS. Simulator design analysis was performed integrally, for simulators with more than one dripper (DRS>1) and with one dripper (DRS=1). Descriptive and numerical data were extracted from the papers and sorted by proposed categories, according to which the types and subtypes of used simulators are determined. The six groups of elements that simulators could consist of have been determined, as well their characteristics, representation and statistical analyses of the available numerical parameters. The characteristics of simulators are analyzed and presented, facilitating the selection of simulators for future research. Description of future simulators in accordance to the basic groups of simulator elements should provide all data necessary for their easier replication and provide a step closer to the reduction of design diversification and standardization of rainfall simulators intended for soil research.

Land degradation caused by erosion processes is a widespread global problem. Rain simulators are one of the tools often used to determine the resistance of soils to erosion processes. The aim of this publication is to present the process of the construction and calibration of a small, portable field simulator which would be implemented in research studies designed to determine the changes in the soils’ shear strength parameters in forested areas (in situ) caused by a change in soil moisture content achieved by the rain simulation. The constructed simulator consists of a metal frame, sprayers (with specific nozzles), a sediment funnel/tray made of metal, water and a sediment collector unit, a water tank and pump, and a set of rubber hoses, manometer, valves, reducers, adapters and other supplementary equipment. The calibration was carried out by using the pluviometric method. The choice of nozzles was based on the criteria of low water consumption (losses), the Christiansen uniformity coefficient (CU) and the possibility of achieving specific downpour intensities for the investigated area. The further calibration of the device consisted of determining the raindrop diameter and the distribution of the rainfall when the simulator is positioned on the slopes (7° and 15°). The achieved rain intensity was 1.7–1.9 mm/min, with a CU of 92.23–93.70% for the raindrop diameters (D₅₀) equal to 1.2 mm. The kinetic energy of the simulated rain (Ke) was 2.82∙10^–6 J. The constructed simulator proved itself to be in accordance with all of the given criteria, and it can successfully be implemented in research studies aimed at determining the resistance of forest soils to erosion processes, infiltration, and sediment yield.

Soil erosion is a global problem that negatively affects the quality of the environment, the availability of natural resources, as well as the safety of inhabitants. Soil erosion threatens the functioning of urban areas, which was the reason for choosing the territory of the Master Plan of Belgrade (Serbia) as the research area. The calculation of soil erosion loss was analyzed using the G2 erosion model. The model belongs to a group of empirical models and is based on the synthesis of the equation from the Revised Universal Soil Loss Equation (RUSLE) and the Erosion Potential Method (EPM). The estimation of soil degradation was analyzed in two time periods (2001 and 2019), which represent the time boundaries of the management of the Master Plan of Belgrade. The novel approach used in this research is based on using the land cover inventory as a dynamic indicator of the urbanization process. Land cover was identified using remote sensing, machine learning techniques, and the random forest algorithm applied to multispectral satellite images of the Landsat mission in combination with spectral indices. Climatic parameters were analyzed on the basis of data from meteorological stations (first scenario, i.e., 2001), as well as on simulations of changes based on climate scenario RCP8.5 (representative concentration pathways) concerning the current condition of the land cover (second scenario). A comparative analysis of the two time periods identified a slight reduction in total soil loss. For the first period, the average soil loss value is 4.11 t·ha−1·y−1. The analysis of the second period revealed an average value of 3.63 t·ha−1·y−1. However, the increase in non-porous surfaces has led to a change in the focus of soil degradation. Increased average soil loss as one of the catalysts of torrential flood frequencies registered on natural and semi-natural areas were 43.29% and 16.14%, respectively. These results are a significant contribution to the study of soil erosion in urban conditions under the impact of climate change.

Rainfall simulators represent often-used equipment for soil research. Depending on their performance, they could be appropriate for some soil research or not. The aim of this research is to provide insight into the capabilities of existing dripping rainfall simulators (DRS) to mimic natural rainfall and the frequency of simulated rainfalls of certain characteristics, facilitate the selection of rain simulators that would best meet the needs of soil research and to reach a step closer to the standardization of rainfall simulators. DRS performance was analyzed integrally, for simulators with more than one dripper (DRS>1) and with one dripper (DRS=1). A statistical analysis was performed for the performance of the DRS, wetted area, drop size, rainfall intensity, duration and kinetic energy. The analysis showed that DRS can provide rainfall that corresponds to natural rainfall, except in terms of the drop size distribution and wetted area. However, usually there are more factors that do not correspond to natural rainfall, such as the median drop size, volume and kinetic energy. Metal and plastic tubes (MT and PT) as the most present dripper types showed a strong relation between the outer diameter (OD) and drop size, while the inner diameter (ID) relation was moderate-to-weak. However, when increasing the range of MT drippers, for diameter size, the relation significance becomes very strong for bouts ID and OD. With the increase in the ID of PT, the relation deviates from the logarithmic curve that represents all drippers together. The sizes of the drops generated by the drippers are mostly in the range between 2 and 6 mm, while the number of drops smaller than 2 mm is relatively small. The intensity and duration of the simulated rain can be successfully produced to match natural values, with the most frequently simulated short-term rainfall of a high intensity. Most simulations were conducted at a fall height of up to 2 m, and then their number gradually decreases as the height gets closer to 5 m. Most simulations (58.6%) occur in the range between 20-90% KE, then 33.0% in a range of 90-100%, with only 8.4% lower than 20% KE.

Извод: Коренов систем има способност да стабилизује падине, поправком физичко-механичких особина земљишта на којем се развија. Морфологија и тенденција кореновог система да збија честице земљишта у једну монолитну масу, коју називамо био-армирано земљиште, доприносе повећању отпорности земљишта на смицање. У раду је приказана упоредна анализа стабилности падина поред путева без и са утицајем кореновог система. Анализе су рађене у циљу заштите саобраћајница, проналажењем оптималног облика кореновог система као алтернативног решења за стабилизацију падина поред путeва. На моделу падине симулиран je утицај четири група вегетације, издвојених на основу морфологије кореновог система (тањираст, срцаст, са израженом срчаницом и недефинисан облик). За сваку изабрану врсту je усвојена вредност кохезије "био-армираног" земљишта (c r). Софтвер за геотехничко нумеричко моделирање-GeoStudio 2007 је коришћен за све анализе стабилности падине. Прорачуном стабилности модела падине без утицаја вегетације утврђено је да падина није стабилна. Увођењем вегетационих група у анализу стабилности постиже се повећање стабилности падине. Највећи утицај на стабилност модела падине има групa 2.-вегетација која има корен са израженом срчаницом, следи група 1.-са срцастим кореном, док су група 3, тањирасти корен, и група 4, недефинисани облик кореновог система, дале најмање вредности. Приказани резултати представљају допринос у избору решења за стабилизацију падина поред путева и спречавању ерозионих процеса.