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Floods are recurring events in Buenos Aires Province, mainly caused by high-intensity precipitation, and in some cases, they persist for long periods. The objective of this study is to analyze how the topography of the central-western portion of Buenos Aires Province determines the occurrence and the extent of floods. The presence of shallow lakes characterizes the area which is controlled by the topography. LANDSAT 5 and 8 images corresponding to periods of drought and flooding in the area were compared with topographic profiles and digital elevation models generated from SRTM 3 arc/sec data. The results showed that in those areas where there are aligned dunes, and after significant storm drain engineering works, during the wet periods, the lakes, their overflows, and the subsequent runoff to the east of Buenos Aires Province flow freely, limiting the flood areas. Due to this topography, the lakes became a more permanent feature of the landscape, even during extreme drought events. In contrast, in those areas where parabolic dunes predominate, the landscape is more affected by droughts and floods. During drought events, we observed a small number of shallow lakes, and during strong storms with high-intensity rainfall, the number of lakes increases and large flooded areas generate damage to agricultural fields and neighboring cities, either due to natural causes or improvised and illegal storm drains. Early warning of flood risks and a systematic territorial ordaining would be the key to the management of the area.

Floods are a consequence of extreme rainfall events. Although surface runoff generation is the origin of discharge, flood research usually focuses on lowlands where the impact is higher. Runoff and sediment delivery at slope and pedon scale receiving much less attention in the effort to understand flood behaviour in time and space. This is especially relevant in areas where, due to climatic and hydrogeological conditions, streams are ephemeral, so-called dry rivers (“wadis”, "ramblas" or “barrancos”) that are widespread throughout the Mediterranean. This paper researches the relationship between water delivery at pedon and slope scale with dry river floods in Macizo del Caroig, Eastern Iberian Peninsula. Plots of 1x1, 1x2, 1x4, and 2x8 m located in the “El Teularet” Soil Erosion and Degradation Research Station were monitored from 2004 to 2014 to measure soil and water delivery. Rainfall and flow at the dry river Barranco de Benacancil were also monitored. Results show that runoff and sediment discharge were concentrated in few events during the 11 years of research. A single flood event was registered in the channel on September 28, 2009, however, the runoff was registered 160 times at the plots. Runoff discharge was dependent on the size of the plots, with larger plots yielding lower runoff discharge per unit area, suggesting short runoff-travel distance and duration. Three rainfall events contributed with 26% of the whole runoff discharge, and five achieved 56% of the runoff. We conclude that the runoff generated at the plot scale is disconnected from the main channel. From a spatial point of view, there is a decrease in runoff coefficient along the slope. From a temporal point of view, the runoff is concentrated in a few rainfall events. These results show that the runoff generated at plot and slope scale does not contribute to the floods except for rainfall events with more than 100 mm day-1. The disconnection of the runoff and sediment delivery is confirmed by the reduction in the runoff delivery at plot scale due to the control of the length of the plot (slope) on the runoff and sediment delivery.

The objective of this work was to propose and evaluate a model to estimate transit water losses and surface runoff in a Brazilian semi-arid basin, fundamental components in the hydrological studies of the region, such as in the verification of hydrological connectivity. The study area was the Orós Reservoir Basin, located in the state of Ceará. The modeling of transit water loss and surface runoff were developed based on the work of Araújo and Ribeiro (1996) and Peter et al. (2014). In the proposed model, the parameter of loss in transit (k) was estimated at 0.027 km-1 for a section of the river basin, and when simulated for other stretches it provided good flow results at the end of the stretch, obtaining an NSE of 82%. The value of the runoff coefficient was estimated at 3% and when evaluating a spatial variation of this coefficient in the basin, the values varied from 2% to 12%, and the use of specialized runoff coefficient (RC) values promoted a higher NSE in the discharge simulation in the basin. It is concluded that the proposed model to estimate transit water losses and surface runoff demonstrated a high efficiency in the simulation of hydrological processes. The basin of Orós reservoir presented a high variability of the coefficient of surface runoff, justifying the need for a greater spatiality of this coefficient in heterogeneous environments.

Snowfalls are important meteorological events affecting the physical environment of the Cantabrian Mountains. This work analyzes the effects of snow on several elements such as relief, landforms, ground climate and snowmelt waters. The ground thermal regime and associated parameters were studied using temperature data loggers and satellite images and were described in combination with observed geomorphological processes and landforms. A geomorphological map was drawn up and trends in climate patterns and runoff were calculated. Ground temperature monitoring in warm years is not optimal, though allow to know the limit conditions for developing cold processes. Results show that geomorphological processes are not significant and that solifluction deriving from snowmelt, is the only active process in years without freeze or with thick snow cover. Snowfall evolution in recent decades in correlation with flow water and climate features provide the certainty that snow distribution also affects efficacy in runoff generation and moves the flow peak in rivers due to early snowmelt.

The objective of this study was to evaluate the water balance in a Red-Yellow Latosol covered by a regenerating rainforest for 30 years in the Una River Basin between April 2016 and March 2017. Field capacity (FC) and permanent wilting-point values (PWP) used to calculate the available water capacity (AWC) in the soil were determined by the soil moisture characteristic curve obtained in pots, which made it possible to determine the soil residual water content (g / g) from the measurement of water tension in 15 Watermark (TM) sensors installed at depths of 40, 60 and 120 cm. Precipitation during the period (1962 mm) was obtained from the automatic weather station located 300 m from the experimental area. Soil surface runoff was obtained from 5 collectors distributed in the experimental area. Precipitation was characterized by a maximum of 454 mm in January 2017 and no rain in July 2016. The actual evapotranspiration was 744 mm. There were 56 runoff events (SR) totaling 60 mm. The average soil water tension remained below 37 kPa in 67% of the studied period, a condition that kept the soil moisture content high. The soil water balance of the tropical forest area, up to 120 cm deep, kept soil water content near its maximum capacity (173 mm) 49% of the time and saturated 51% of the time, so that it generated deep drainage beyond 120 cm deep and 1023 mm deep.

This study aims to evaluate the influence of the ground cover rate by crop residues and the rain time elapsed after the application of liquid swine slurry (LSS) under losses of water, sediments, and phosphorus (P). The study was carried out under a Humic Cambisols. Two areas were delimited: with and without the application of LSS. Each area was subdivided into four levels of crop residues: 5%, 35%, 65%, and 95%. Vegetable residues present in the area, from corn and black oat, were used. Three collecting gutters of 0.60 m² were installed in each subplot. Simulated rain was carried out on these, and the runoff volume collected for quantification and determination of losses. With LSS application, increase in the cover rate by crop residues reduces 0.3 mm h-1 the runoff volume and 1.67 mg m-2 reactive soluble P (H2O-P). The sediment losses in the first collection after the beginning of the rain were 23 times lower in the soil with 95% ground cover than in the soil with 5% ground cover. The loss of total P (total-P) decreases with the increase of the ground cover of the soil and increases in the same way with the increase of the time.

The 0-1 test algorithm is a new nonparametric method for detecting the presence of chaos in the nonlinear science disciplines. This test applies directly to the time series and does not depend on phase-space reconstruction. This thesis take logistic map as an example, the numerical results demonstrate the advantages of the method. Then, the runoff time series (2002-2009) collected by the six hydrologic stations (Tangnaihai, Lanzhou, Toudaoguai, Longkou, Sanmenxia and Huayuankou) of Yellow River, are selected to detect the existence of chaotic behaviour in different spatial scales. The asymptotic growth rates of Kc are 0.8751, 0.8985, 0.9783, 0.9793, 0.9848 and 0.9976, respectively. Multiple spatial scales runoff data of Yellow River Basin shows chaotic characteristic. The minimum value of Kc is in the upper reaches of the Yellow River (Tangnaihai). The maximum value of Kc is in the lower reaches of the Yellow River (Huayuankou). The spatial runoff process changes greatly in temporal and spatial scales. And drainage area is an important factor in causing chaos variation. The conclusion illustrates the feasibility of this method and provides scientific data for runoff prediction.

In this study, the performance of the HEC-HMS model was evaluated for the simulation of rain-runoff processes in a paramo basin of approximately 21. 8 km2, south of Ecuador. The calibration and validation comprises the period of July-2013 to June-2016 with daily data. The Soil Moisture Accounting (SMA) method was used to compute the water flow in the soil. For the rainfall distribution, the Thiessen method was used, while the Evapotranspiration was calculated with the Penman-Monteith equation. The results revealed that (1) 83% of the water infiltrates the soil while only 17% is retained in plants and the soil surface, (2) the water is retained for approximately 42 days before reaching the river and (3) that more than 60% of the flow corresponds to sub-surface flow.

ABSTRACT The aim of this study was to evaluate the loss of water and nutrients by laminar runoff in different soil tillage systems subjected to natural rainfall. Five experimental plots were established for the cultivation of cotton in the city of Campo Verde - MT, with the following treatments: CTDP = conventional soil tillage and planting of the cotton in the direction of the slope; CTCP = conventional tillage and contour planting; CP = tillage of soil with a disk harrow and a leveling harrow, followed by contour planting; CoP = tillage by two passes of a leveling harrow followed by contour planting; MTCP = minimum tillage with contour planting. The losses of water by laminar runoff in were determined by the stored volume and samples were taken to quantify nutrient losses in water (nitrite, nitrate, phosphate and potassium). The losses of water by runoff were highest for the CTDP; intermediate for the treatments CTCP, CoP and MTCP, and lowest for the CP. Potassium (K) was the nutrient that had the highest concentrations and losses in water: the highest values were found in the CTDP and CTCP tillage systems, whereas the lowest were observed for the CP, CoP, and MTCP treatments. The concentrations and the losses by water erosion of phosphate (PO43-), nitrite (NO2–), and nitrate (NO3–) were low in all of the soil tillage systems compared to the losses of K in this study.

This paper examines sediment yield rates and its response to control variables in the principal rivers of Colombian draining into the Caribbean and Pacific coasts. Based on a multi-year dataset of sediment load from six rivers, including Mira, Patía, and San Juan on the Pacific margin, and Magdalena, Atrato, and Sinú, on the Caribbean basin, various morphometric, hydrologic, and climatic variables were estimated in order to understand and predict the variation in sediment yield. A multiple regression model, including two control variables, runoff and relief ratio (the ratio of the maximum height of the drainage basin and the basin length), explains 83% of the variance in sediment yield. This model is efficient (ME = 0.93) and is a valuable tool for predicting total sediment yield from Colombian rivers. These two selected estimators refer to the relative importance of the fluvial transport component in the sediment routing system. Thus, regional-scale variance of sediment yield in the Andean basins of Colombia seems to be explained by the combined influence of tectonics (relief) and surface runoff available for weathering and transport processes. In general, high sediment yielded rivers are high runoff systems with narrow alluvial plains (i.e. Pacific rivers), while low sediment yielded rivers like the Caribbean systems, contain large sections with not significant gradient in their longitudinal profiles. These sections coincide with large floodplains, which all provide sediment storage capacity within the catchments. When considering the three gauged Pacific rivers at their furthest downstream stations, the combined annual sediment load from these rivers into the Pacific Ocean is ~40 Mt yr–1. In contrast, the Magdalena, Atrato and Sinu rivers deliver ~173 Mt yr-1 into the Caribbean. Overall, Andean rivers of Colombia exhibit the highest sediment yields of all medium-large sized rivers of South America due to the interplay of (1) high rates of runoff (1,750-7,300 mm yr-1), (2) steep relief within catchments, (3) low values of discharge variability (Qmax-Qmin), and (4) episodic sediment delivery due to either geologic events or climatic anomalies.

Episodes of precipitation are part of the climate variability of a region; however, when associated with impermeability processes of the soils and inefficient urban drainage, they increase the rates of floods and overflows events, which cause severe inconvenience and damage for the population. Thus, this study correlates the record of 60 occurrences of floods and overflows, in the Ronda stream watershed, located largely in the urban area of the city of Ponta Grossa, between the years 1980 and 2017. Half of the occurrences happened due to extreme events, that is, with precipitation equal to or greater than 50 mm. Many occurrences occurred in areas considered to be at risk, mainly in the floodplain of the Ronda stream.

ABSTRACT: Ultramafic (UM) rocks are defined as igneous rocks that contain more than 90% of mafic minerals. Soils derived from ultramafic rock are generally nutrient-deficient and have concomitant high concentrations of potentially phytotoxic trace elements (Ni, Cr, Co, Mn). Consequently, to assess the dynamics of nutrients and metals in the ultramafic complex of Niquelândia (Brazil), soil solutions have been sampled in soils characterized by high Cr(VI) availability. The metal contents in surficial water have also been analyzed to investigate the metals’ leaching and mobility. Soil solutions featured low nutrient contents, a large Ca:Mg imbalance, and high Ni and Cr concentrations. Chromium was present in its toxic dissolved form (Cr(VI)) in the soil and surficial solutions. Metals concentrations were often above the toxic limit for biota and were therefore able to affect soil functioning. Ni behavior in the topsoil appeared to be primarily controlled by organic matter, while Cr was more likely to be released from Fe-oxides by anionic exchange. This result agreed with the Cr(VI) lability assessed using isotopic exchange kinetics in a companion study. In these serpentinic tropical soils, the highly leached Fe-oxide horizons appear to play a large role in the sequestration and diffuse leaching of labile Cr(VI) and Ni, respectively, in the deeper part of soil profiles and the topsoil. At the catchment scale, surficial solutions results suggest that metals may be exported to surrounding ecosystems that are not adapted to these metals.

Through the implementation of geographic information systems (GIS) and images of the study area obtained by remote sensors, the curve number method (NC) was implemented in this research, in order to determine potential recharge zones in two micro-basins in the aquifer region called Zona Bananera, located in the department of Magdalena in Northern Colombia. Potential infiltration of the area was estimated and the hydrological response for precipitation events with different return periods was evaluated. The predominant hydrological soil groups were found to be A and B, with 77.4% (84115.2 ha) in the Sevilla River micro-basin and 81.6% (7466.1 ha) in La Aguja micro-basin. The Sevilla River micro-basin showed both the best water regulation and enhancement of the infiltration process, evidenced by the existence of low as well as medium values ​​of curve number and potential surface runoff. The highest values ​​of potential runoff were in the middle and lower part of the micro-basins, where there are extensive areas covered with banana crops; indicating that anthropic intervention is a determining factor in the area’s hydrological response. Under current conditions, the micro-basins show a minimal risk of erosive processes for rainfall with return periods of less than 5 years, due to runoff occurrence of less than 100 mm. Within the study area, it was found that approximately 3380 hectares show favorable conditions to contribute to the recharge of the Zona Bananera aquifer, making it a strategic conservation area.

This article discusses the use of green roofs as rainfall water storage in its soil matrix. The methodology is analytical based on mathematical models, where runoff produced in an urban area is compared with current conditions of ordinary roofs with ceramic or bituminous materials as the original scenario, against another where green roofs are used. The study area is located in the Palavecino municipality of Lara state in Venezuela, in the flood zone of Quebrada Tabure. In this research, a quantitative comparison of the direct runoff hydrographs of the proposed scenarios was used, obtaining as a main result the reduction of runoff between 60% and 80% according to the period of return. An interesting point of this research was the incorporation of the routing of hydrographs on the roofs, reducing even more the peak flow over 90%, and delaying the peak time of the generated hydrographs between 10 and 12 minutes while the total duration of the hydrographs increase more than three times.

ABSTRACT The greater probability of small rainfall events occurring in semi-arid regions, and the little understanding of their role in hydrological processes, has led to this investigation of surface runoff generated during these events in two adjacent micro basins in the Brazilian semi-arid region. The types of plant cover to be investigated were the Phytogeographical Caatinga Domain under regeneration for 35 years (CPDReg) and thinned CPD (CPDThin), which consisted of the elimination of trees with a diameter of

The objective of this paper is to present the development and application of a method to estimate the heavy metal (HM) contribution derived from the wash-off by runoff on road-deposited sediments (RDS) in a high-altitude megacity (Bogota, Colombia). The method is based on the development of a HM wash-off equation which considers two processes: HM transportation and HM leaching. HM contribution by runoff ranges between 24.7% and 50.3%, relative to the total mass per unit area of HMs associated with dry-weather RDS (Mn, Cd, As, Zn, Cu, Ba, Pb, and Fe). The HMs that show a greater contribution are Cd, Zn, and Mn. RDS size fraction below 250 μm contributes on average 81.6% of the total HM load washed-off by runoff. The findings suggest that the RDS size fraction below 250 μm must be the reference fraction for the control systems design of HM pollution in Bogota city.

Erosion is the main form of degradation in the world, consequently of loss of soil, water and nutrients, provoking direct and indirect damages. The objective of this work is to quantify N, P and K losses by water erosion under simulated rainfall conditions by the application of six erosion tests in continuous cultivation of seasonal cycle species, including isolated and intercropped crops. The study was carried out in the field at the Experimental Station of Agronomy in Eldorado do Sul (RS), Brazil, in a typical Dystrophic Red Argisol. For the analysis of nutrient loss, six erosion tests with simulated rainfall were applied to the treatments between the end of October and mid-December, using the rain simulator with swivel arms of Swanson. The losses ofNand P were influenced by surface conditions,with the partial removal of crop residues and the non-mobilization of the soil. The exception was K, due to its high solubility in the soilwith a lowcolloidal activity, which was easily lost in the soilwater surface runoff, regardless of total soil surface coverage by crop residues.

A combination of high temporal variability and spatial heterogeneity of rainfall, soil surfaces, and plant cover is the cause of the complex hydrological response in arid/semiarid regions. Under these premises, long-term monitoring is necessary to capture drivers controlling the response of these areas and to be able to model and predict their reaction. A succinct, up-to-date review of the databases and results produced by two representative micro-catchments in the most arid extreme of Europe, Almería (SE Spain), is presented with the aim to show how the different precipitation patterns, during a 20-year period, influence the hydrological behavior on different lithologies and soil surfaces. The problems encountered about the functioning of these experimental stations, including the generation and maintenance of long-term databases, is also reviewed.

ABSTRACT Changes in the Brazilian Forest Code (BFC) have soften the criteria for recovery and conservation of permanent preservation areas (PPAs), enhancing processes related to surface runoff. The aim of this study is to understand the effects of changes in PPA classification criteria established by BFC of 2012 to the detriment of BFC from 1965 considering the surface runoff response in the basin draining the upper Marrecas River valley in the flow peaks. The HEC–HMS model was used to simulate flow peaks considering three land-use scenarios, representative of the current use, adapting it to PPAs fitted to the BFC of 1965 and 2012 and seven precipitation return periods. In the proposed scenarios, the use of BFC of 2012, to the detriment of that from 1965, would imply a PPA reduction from 44.5% to 13.7%, resulting in a 22.1% increase in the average flow peaks, not representing, however, a significant reduction in the flow peaks when compared to the scenario representing the current land use. Therefore, when compared to BFC of 1965, in the Brazilian new Forest Code PPAs were reduced by 69.2%, increasing peak flows by up to 30.7%, thus minimizing the legal possibilities of flood mitigation to the urban perimeter of Francisco Beltrão, Paraná State, Brazil.

A portable rainfall simulator was built for assessing runoff and soil erosion processes at interrill scale. Within this study, requirements and constraints of the rainfall simulator are identified and discussed. The focus lies on the calibration of the simulator with regard to spatial rainfall homogeneity, rainfall intensity, drop size, drop fall velocity and rainfall kinetic energy. These parameters were obtained using different methods including a Laser Precipitation Monitor. A detailed presentation of the operational characteristics is given. The presented rainfall simulator setup featured a rainfall intensity of 45.4 mm·h-1 with a spatial homogeneity of 80.4% based on a plot area of 0.64 m². Because of the comparatively low drop height (2 m), the diameter-dependent terminal fall velocity (1.87 m·s-1) was lower than benchmark values for natural rainfall. This conditioned also a reduced rainfall kinetic energy (4.6 J·m-2·mm-1) compared to natural rainfall with same intensity. These shortfalls, a common phenomenon concerning portable rainfall simulators, represented the best possible trade-off between all relevant rainfall parameters obtained with the given simulator setup. Field experiments proved that the rainfall erosivity was constant and replicable.

ABTSRACT Erosion risk mapping and assessment are important for planning of natural resource management tool. The objective of this study was to simulate different scenarios of land use in the Sub-Middle of the São Francisco River Basin using the Soil and Water Assessment (SWAT) model to analyze the effects of changes in sediment yield, making comparisons with the present land use classification. The scenario analysis was (i) vegetation type characteristic of the semiarid region, (ii) growing corn and (iii) bare soil. For calibration procedure, the first three years of time series from 1993 to 1994 were validated using data from 1995 to 2004. The SWAT model employs the Modified Universal Soil Loss Equation (MUSLE) to compute soil erosion data. The results of simulations for different land uses allowed the identification of areas with a high potential for erosion by water. The major impact produced by sediment inflow was in the bare soil scenario, corresponding to an increase of 93.7% over the current land use. The landscape management in river basins using SWAT model can help identify areas particularly susceptible to erosion process.

Abstract The objective of this work was to assess the risk of phosphorus losses by runoff through an index based on the degree of P saturation (DPS), in cropland soils of Southern Brazil. Sixty-five highly representative cropland soils from the region were evaluated. Three labile P forms were measured (Mehlich-1, Mehlich-3, and ammonium oxalate), and four P sorption indexes were tested (phosphorus single sorption point and Fe+Al determined with the three extractors). Water-extractable P (WEP) was used as an index of P susceptibility to losses by surface runoff. The DPS was determined from the ratio between labile P and each sorption index. DPS values obtained from the ratio between Mehlich-1 P and the single P sorption point ranged from 1 to 25%, whereas those from Mehlich-1 P and Fe+Al (ammonium oxalate) ranged from 1 to 55%. All DPS types were highly correlated with WEP. From a practical stand point, the DPS obtained with both P and Fe+Al extracted with Mehlich-1 can be used to estimate the risk of P losses by runoff in soils of Southern Brazil.

ABSTRACT Eutrophication of surface waters remains a major use-impairment in many countries, which, in fresh waters, is accelerated by phosphorus (P) inputs from both point (e.g., municipal waste water treatment plants) and nonpoint sources (e.g., urban and agricultural runoff). As point sources tend to be easier to identify and control, greater attention has recently focused on reducing nonpoint sources of P. In Brazil, agricultural productivity has increased tremendously over the last decade as a consequence, to a large extent, of increases in the use of fertilizer and improved land management. For instance, adoption of the “4R” approach (i.e., right rate, right time, right source, and right placement of P) to fertilizer management can decrease P runoff. Additionally, practices that lessen the risk of runoff and erosion, such as reduced tillage and cover crops will also lessen P runoff. Despite these measures P can still be released from soil and fluvial sediment stores as a result of the prior 10 to 20 years’ management. These legacy sources can mask the water quality benefits of present-day conservation efforts. Future remedial efforts should focus on developing risk assessment indices and nonpoint source models to identify and target conservation measures and to estimate their relative effectiveness. New fertilizer formulations may more closely tailor the timing of nutrient release to plant needs and potentially decrease P runoff. Even so, it must be remembered that appropriate and timely inputs of fertilizers are needed to maintain agricultural productivity and in some cases, financial support might also be required to help offset the costs of expensive conservation measures.

El presente trabajo de investigación se realizó empleando modelos matemáticos, con la finalidad de comparar la escorrentía producida en un urbanismo con condiciones actuales de techos de tejas criollas, contra otro donde se usan estructuras o dispositivos de almacenamiento y retención de agua en casas, patios, parcelas, calles y contra urbanismos en general. Se seleccionó una zona de estudio en el Estado Lara (Venezuela), en el municipio Palavecino, en las inmediaciones de la Quebrada Tabure, considerando los techos verdes desde el punto de vista de reductores de escorrentía. Se elaboró una aplicación llamada “TechosVerdes.py” en el programa de licencia libre Python, con aproximadamente 4600 líneas de código para calcular los hidrogramas de los techos, patios, calles y áreas verdes, basándose en un mosaico creado con imágenes tipo raster en el programa Quantum Gis. La investigación se basó en la comparación directa de trece escenarios hipotéticos, donde se utilizó techos verdes y adicionalmente, tanques de almacenamiento y brocales, con un escenario original en condiciones actuales, sin alteraciones. Se obtuvo como resultado en los hidrogramas calculados para los escenarios hipotéticos, que el caudal pico disminuye, achatándose el hidrograma. This research was carried out using mathematical models in order to compare the runoff from an urban planning with handmade tiles roofs in actual conditions, with one where structures or storage devices and water retention in houses, yards are used, parcels, streets and housing complexes in general. A study area in the state of Lara, Venezuela, in Palavecino municipality, near Quebrada Tabure, was selected and green roofs are considered from the point of view of reducing runoff. An application called "TechosVerdes.py" was made under the license free Python program with approximately 4600 code lines was developed to calculate hydrographs from roofs, patios, streets and green areas, based on a mosaic created with type raster images in the Quantum Gis program. The research was based on the direct comparison of thirteen scenarios where green roofs were used and additionally, storage tanks and parapets, with an original scenario on current conditions without alterations. In the hydrographs produced by hypothetical scenarios it was determined that the peak flow decreases squashing the hydrograph.