Surface Runoff Coefficient Research Articles

Study of Land Use Change for Preparation of Watershed Management Planning

In an integrated approach, watershed management crucially needed to maintain condition and quality of watershed. Land use change is one of main causes of watershed condition and quality changing. Therefore, it required planning alternatives suggestions to prevent and recover the watershed degradation. The research was carried out to study about watershed changes and degradation due to land use change and investigating for the best alternative to restore Ciujung Watershed, Banten, Indonesia using Soil and Water Assessment Tool (SWAT) model. Research result showed that the reduced of forest area (plantation forest, primary dryland forest, secondary dryland forest) and the increased of dryland agricultural, dryland mixed farming (mixed with bush, plantation, rice fields and bushes) caused the increase of river flow. Several alternative soil and water conservation techniques as if reforestation, agroforestry, strip cropping, contour cropping, dam building and the application of bio-retention hole could be done for land management to maintain and improve the condition and quality of Ciujung Watershed which is indicated by a decrease in values of River Regime Coefficient (RRC), surface runoff coefficient, and sediment yield.

Investigating runoff formation dynamics: field observations at Cape Fear experimental plot.

In this paper, we explore the dynamics of surface runoff formation in an outdoor experimental plot, Cape Fear, by reporting the relationships among rainfall, runoff, and soil moisture for 101 rainfall-runoff events observed in the time span of more than five years (January 2014-March 2019). Cape Fear is a recently developed 7 × 7m2 experimental plot that combines features from both small scale facilities and catchment-scale experimental hillslopes, thus leveraging observation of major hydrological variables at high temporal and spatial resolution. Despite the small dimension and simplicity of the plot, the relations among hydrological variables are unexpectedly quite spread. Experimental results seem to suggest that Cape Fear runoff response presents an increasing and non-linear relationship with rainfall, with a surface runoff coefficient increasing for higher rainfall. Direct runoff apparently increases with soil moisture, while initial abstraction seems not to be influenced by rainfall and is found to decrease with increasing soil moisture. Observations suggest that complex interactions between soil moisture conditions and rainfall pattern properties modulate the plot response.

Surface runoff estimate in urbanized area from the Rangel Stream basin at São Sebastião do Paraíso/MG

Urban growth generates impacts over land usage and may alter the hydrological systems of a microbasin. The unregularized occupation impermeabilizes the soil and increase the volume and velocity of superficial runoff. Thus, inundation, flood and overflow occur in urban areas. In this context, this work’s objective was to quantify the impact of soil impermeabilization over the surface runoff coefficient in the microbasin of the Liso stream at São Sebastião do Paraíso county, Minas Gerais. Google Earth satellite images were used for the identification and determination of occupied urban areas, and ArcGis 10.4 software was utilized for letter elaboration, which determined the permeable areas. It was taken as hypothesis that the surface runoff coefficient is equal to one in impermeabilized areas. In addition, green areas and unoccupied allotments were considered as permeable areas. In order to determine the impermeabilized area, the permeable area was subtracted from the total area. The surface runoff coefficient was estimated as the relation between the impermeabilized area and the total urbanized area. The results have demonstrated that the urbanized area located in the microbasin grew 44,47% in ten years. Therefore, the estimate of surface runoff coefficient utilized in this paper can be a good alternative for city halls to analyze the urban growth and aid in the circumscription of residential areas or green areas, since it is a simple method which requires data easily generated through maps.

ANALISIS KOEFISIEN LIMPASAN PERMUKAAN KOTA MAKASSAR DENGAN METODE COOK

Rain falling on the Watershed will turn into a stream in the river, this is because the rainwater is not entirely infiltrated into the soil, the unabsorbed water is called surface runoff. Factors affecting runoff are meteorological elements and drainage elements. This study aims to calculate the surface runoff coefficient using land cover maps 2017 and 2050, slope and soil type as parameters. Cook method divides the watershed characteristics into 4 sections as parameters to calculate the runoff coefficient of topography, soil type, vegetation cover and surface deposit. Each parameter is weighted based on its characteristics to calculate the coefficient of surface runoff symbolized by the letter C. The analysis results show that in the year 2017 obtained the value of C = 0.4734 and for the year 2050 C = 0.4785. There's a difference of 0.0051 coefficient of runoff value between land use map and land cover in 2017 and 2050. The results of this study will be used to calculate the flood discharge design in the object of research in Makassar City.

Runoff Response to Soil Moisture and Micro-topographic Structure on the Plot Scale

Structural hydrological connectivity has been proposed to describe the geological structure of the landscape as well as to explain hydrological behaviors. Indices based on the topological or soil condition were developed to interpret their relationships. While previous studies mainly focused on well-instrumented catchments which are narrow in humidity or temperate zone, the hydrological responses to structural connectivity at the plot and hill slope scale as well as in arid or semi-arid climate conditions remain unclear. This study was conducted in the semi-arid mountainous region of northern China in Haihe Basin which is the source of water of about 350 million people. Experiments were conducted during the rainy season in 2012 and 2013 using four runoff plots. Two indices, flow path length (FL) based on topography and integral connectivity scale length (ICSL) based on soil moisture conditions, developed to represent hydrological connectivity structure and the runoff response to rainfall were analyzed. The results showed that the surface runoff coefficient was strongly and positively linearly correlated to FL, and the correlation between subsurface flow and ICSLs was quadratic. Plots with shorter FL required more rainfall to generate surface runoff. In the shallow soil layer, when the ICSLs are relatively low, the soil can store more water and less rainfall feeds subsurface runoff. Further analysis indicated that improved shallow soil connectivity conditions might enhance the water-holding capacity and lead to lower water yields for each event. This study demonstrated that hydrological structure connectivity could explain the mechanism of runoff generation in semi-arid areas while further experiments should be undertaken to find the threshold-like relationship between FL and surface runoff as well as the influence of plant cover on hydrological behaviors.

Analysis of the effect of land use changes on hydrology characteristics. Case study: the catchment area of Koto Panjang Hydroelectric Power

This study aims to analyze the hydrological characteristics as a result of changes in land use with the help of the SWAT hydrological model and can provide recommendations on the best land use in the Koto Panjang Electric Power catchment area. Based on the results of the analysis using the SWAT hydrological model, it was seen that there were effects of land use changes in 2011 and 2014 on hydrological characteristics; yield of water (WATER YLD) of 2,413.38 mm, and 1.008, 65 mm, runoff coefficient (C) of 0.19 and 0.063 respectively, and river regime coefficient (KRS) of 11.449 and 12.212, respectively. The best land use to be developed in agricultural cultivation areas as a recommendation to maintain water stability in the Koto Panjang hydropower catchment area is a simple and complex agroforestry pattern in scenario III, which is run together with hydrological characteristics in the form; water yield (WATER YLD) of 1,038.41, surface runoff coefficient (C) of 0.023, and river regime coefficient (KRS) of 11.13. The hydrological characteristics in scenario III are far better than 2014 land use characteristics (existing).

Simulation study on effect of permeable pavement on reducing flood risk of urban runoff

Permeable pavement is part of the low impact development (LID) measurement, which can decrease urban surface runoff coefficient and flood peak flow. In this paper, a two-way, six-lane road in Nanjing was selected as the study area. Storm water management model (SWMM) was used to simulate the effect of different pavement structures (drainage surface, permeable pavement and permeable road) under different rainfall conditions on reducing surface runoff and controlling urban stormwater. The simulation results show that the drainage surface can reduce part of surface runoff, but it has no influence on the reduction and hysteresis of flood peak. The permeable pavement can reduce part of surface runoff and flood peak and can delay peak time. The permeable road has better effect on reducing runoff coefficient and flood peak, which can effectively reduce the pressure of urban drainage and reduce the risk of stormwater flood.

SPATIAL ANALYSIS OF LAND USE IN BUMIAJI SUBDISTRICT, BATU CITY, EAST JAVA, INDONESIA

The Bumiaji area is an upstream river basin that has undergone land changes from an undeveloped to a developed area, which may cause a disturbance in the river basin. This research investigates the river basin using secondary data covering land use, land slope, rainfall, and soil types. The quality indicator of a river basin is measured from the quantity of surface runoff. The bigger the scale of the surface runoff is, the lower the quality of the river basin. This research aims to examine the effect of land use changes on the river basin condition, using surface runoff as the indicator. The result shows that the change of land use at Bumiaji affects the surface runoff coefficient and river discharge increment in the Bumiaji river basin. It is concluded that the runoff coefficient (C) increased in sub-river basins one to four, while it decreased in sub-river basin five.

Sensitivity Analysis of the Surface Runoff Coefficient of HiPIMS in Simulating Flood Processes in a Large Basin

To simulate flood processes at the basin level, the GPU-based High-Performance Integrated Hydrodynamic Modelling System (HiPIMS) is gaining interest as computational capability increases. However, the difficulty of coping with rainfall input to HiPIMS reduces the possibility of acquiring a satisfactory simulation accuracy. The objective of this study is to test the sensitivity of the surface runoff coefficient in the HiPIMS source term in the Misai basin with an area of 797 km2 in south China. To achieve this, the basin was divided into 909,824 grid cells, to each of which a Manning coefficient was assigned based on its land use type interpreted from remote sensing data. A sensitivity analysis was conducted for three typical flood processes under four types of surface runoff coefficients, assumed a priori, upon three error functions. The results demonstrate the crucial role of the surface runoff coefficient in achieving better simulation accuracy and reveal that this coefficient varies with flood scale and is unevenly distributed over the basin.

Effects of land use on soil properties and hydrological processes at the point, plot, and catchment scale in volcanic soils near Turrialba, Costa Rica

Deforestation and conversion to crop land and pasture in tropical regions has important effects on hydrological processes including increased flooding and reduced drought flows. We investigated: 1) differences in soil characteristics between four tropical land uses (forest, coffee, sugar cane and pasture), and 2) how hydrological processes differ between these four land uses. We measured bulk density, saturated hydraulic conductivity (Ksat), soil moisture content, catchment discharge and conducted infiltration, mass balance, and dye tracing tests at four catchments within the Reventazón watershed near Turrialba, Costa Rica at the point scale, the plot scale (1m3), and the catchment scale (1–6ha). While most of the soil characteristics between the field sites were similar, bulk density at the forest site (0.7gcm−3) was significantly lower than bulk density at the other field sites (1.0gcm−3). At the forest and coffee sites, Ksat (>32mmhr−1) was at least twice the Ksat (<13mmh−1) at the sugar cane and pasture sites. During mass balance experiments at the plot scale, sugar cane and pasture had greater surface runoff and lateral flow coefficients (>30%) than the coffee and forest (<16%). Irrigated dye experiments revealed roots and macropores were important flow paths in the forest and coffee sites, while machinery, cattle compaction, and lack of large roots impacted the sugar cane and pasture hydrological processes. At the surface, seasonal soil moisture in the sugar cane and pasture sites was consistently greater than in soils of the forest and coffee sites. At the catchment scale, discharge was minimal (<10%). The sugar cane site had the greatest catchment scale discharge coefficient (7%), event frequency, depth and rate. Overall, the forest and coffee land use had greater water storage capacity, hydraulic conductivity, and percolation compared to the pasture and sugar cane sites. The interplay of different root distributions, compaction, and different soil moisture dynamics affected infiltration and storage dynamics. These findings have important implications for tropical groundwater recharge and runoff predictions.

MODEL OF SOIL AND WATER CONSERVATION MEASURES APPLICATION BASED ON DISTRICT SPATIAL PLANNING IN MAMASA WATERSHED, SOUTH SULAWESI

Depletion of watershed carrying capacity cannot be omitted from mismanagement of the watershed. The integration between SWAT model and remote sensing data are able to identify, assess, and evaluate watershed problem as well as a tool to apply the mitigation of the problem. The aim of this study was to arrange the scenario of watershed management, and decide the best recommendation of sustainable watershed management of Mamasa Sub Watershed. The best recommendation was decided by hydrology parameters, e.i. surface runoff, sediment, and runoff coefficient. Hydrology characteristics of Mamasa Sub Watershed was analyzed based on land use data of year 2012 and climate data for period of 2010-2012. The scenarios were application of bunch and mulch in slope 1-15%; bunch terrace (scenario 1), mulch and strip grass in slope 15-25% (scenario 2), alley cropping in slope 25-40% (scenario 3), and combination scenario 1, 2, 3 with agroforestry in slope &gt; 40% (scenario4). Surface runoff value of Mamasa Sub Watershed is 581.35 mm, while lateral flow, groundwater flow, runoff coefficient, and sediment yield of 640.72 mm, 228.17 mm, 0.29, and 187.213 ton/ha respectively. Based on the scenarios simulation, the fourth scenario was able to reduce surface runoff and sediment yield of 33.441% and of 51.213%, while the runoff coefficient declined to 0.194. Thereby, the fourth scenario is recommended to be applied in Mamasa Sub Watershed so that the sustainability in the watershed can be achieved.

Model of Soil and Water Conservation Measures Application based on District Spatial Planning in Mamasa Watershed, South Sulawesi

Depletion of watershed carrying capacity cannot be omitted from mismanagement of the watershed. The integration between SWAT model and remote sensing data are able to identify, assess, and evaluate watershed problem as well as a tool to apply the mitigation of the problem. The aim of this study was to arrange the scenario of watershed management, and decide the best recommendation of sustainable watershed management of Mamasa Sub Watershed. The best recommendation was decided by hydrology parameters, e.i. surface runoff, sediment, and runoff coefficient. Hydrology characteristics of Mamasa Sub Watershed was analyzed based on land use data of year 2012 and climate data for period of 2010-2012. The scenarios were application of bunch and mulch in slope 1-15%; bunch terrace (scenario 1), mulch and strip grass in slope 15-25% (scenario 2), alley cropping in slope 25-40% (scenario 3), and combination scenario 1, 2, 3 with agroforestry in slope &gt; 40% (scenario4). Surface runoff value of Mamasa Sub Watershed is 581.35 mm, while lateral flow, groundwater flow, runoff coefficient, and sediment yield of 640.72 mm, 228.17 mm, 0.29, and 187.213 ton/ha respectively. Based on the scenarios simulation, the fourth scenario was able to reduce surface runoff and sediment yield of 33.441% and of 51.213%, while the runoff coefficient declined to 0.194. Thereby, the fourth scenario is recommended to be applied in Mamasa Sub Watershed so that the sustainability in the watershed can be achieved.

Modeling Surface Runoff and Water Fluxes over Contrasted Soils in the Pastoral Sahel: Evaluation of the ALMIP2 Land Surface Models over the Gourma Region in Mali

Abstract Land surface processes play an important role in the West African monsoon variability. In addition, the evolution of hydrological systems in this region, and particularly the increase of surface water and runoff coefficients observed since the 1950s, has had a strong impact on water resources and on the occurrence of floods events. This study addresses results from phase 2 of the African Monsoon Multidisciplinary Analysis (AMMA) Land Surface Model Intercomparison Project (ALMIP2), carried out to evaluate the capability of different state-of-the-art land surface models to reproduce surface processes at the mesoscale. Evaluation of runoff and water fluxes over the Mali site is carried out through comparison with runoff estimations over endorheic watersheds as well as evapotranspiration (ET) measurements. Three remote-sensing-based ET products [ALEXI, MODIS, and Global Land Evaporation Amsterdam Model (GLEAM)] are also analyzed. It is found that, over deep sandy soils, surface runoff is generally overestimated, but the ALMIP2 multimodel mean reproduces in situ measurements of ET and water stress events rather well. However, ALMIP2 models are generally unable to distinguish among the two contrasted hydrological systems typical of the study area. Employing as input a soil map that explicitly represents shallow soils improves the representation of water fluxes for the models that can account for their representation. Shallow soils are shown to be also quite challenging for remote-sensing-based ET products, even if their effect on evaporative loss was captured by the diagnostic thermal-based ALEXI. A better representation of these soils, in soil databases, model parameterizations, and remote sensing algorithms, is fundamental to improve the estimation of water fluxes in this part of the Sahel.

Processes of runoff generation operating during the spring and autumn seasons in a permafrost catchment on semi-arid plateaus

There is a lack of knowledge about how to quantify runoff generation and the hydrological processes operating in permafrost catchments on semi-arid plateaus. To understand how freeze-thaw cycles affect runoff generation processes in permafrost catchments, a typical headwater catchment with continuous permafrost on the Tibetan Plateau was measured. A new approach is presented in this study to account for runoff processes on the spring thawing period and autumn freezing period, when runoff generation clearly differs from that of non-permafrost catchments. This approach introduces a soil temperature-based water saturation function and modifies the soil water storage curve with a soil temperature threshold. The results show that surface soil thawing induced saturation excess runoff and subsurface interflow account for approximately 66–86% and 14–34% of total spring runoff, respectively, and the soil temperature significantly affects the runoff generation pattern, the runoff composition and the runoff coefficient with the enlargement of the active layer. The suprapermafrost groundwater discharge decreases exponentially with active layer frozen processes during autumn runoff recession, whereas the ratio of groundwater discharge to total runoff and the direct surface runoff coefficient simultaneously increase. The bidirectional freezing of the active layer controls and changes the autumn runoff processes and runoff composition. The new approach could be used to further develop hydrological models of cold regions dominated by permafrost.

Comparison of the results of a small-plot and a large-plot rainfall simulator – Effects of land use and land cover on surface runoff in Alpine catchments

Many surveys with differently sized rainfall simulators have been conducted in the past to study runoff and erosion processes on the plot scale. Concerning the understanding of runoff processes on the slope scale, comparative studies have shown that sprinkling devices with large plot sizes (≥40m2) produce more representative results than small-plot rainfall simulators (4m2 and less). Nevertheless, the latter ones are frequently used due to their portability and the reduced effort and water demand compared to large-plot simulations. In this study the results of torrential rain (100mm h−1) experiments using a small (1m2) dripper device and a large (40–80m2) spray device are compared regarding to identify site characteristics which allow estimating the representativeness of surface runoff coefficients measured with a small-plot rainfall simulator. We conducted 39 small-plot (1m2) and 14 large-plot (40–80m2) rainfall simulations at eight selected experimental sites in the Eastern Alps with differing land cover, land use, intensity of grazing and antecedent soil moisture content. At sites with intensive grazing, due to topsoil compaction and the shortened flow path, the small-plot device delivered significantly higher runoff coefficients than the large-plot device. At mainly mowed grassland sites with at most a short grazing period in autumn both sprinkling devices showed similar results or even lower runoff coefficients compared with the results of the large-plot simulator. The measured surface runoff coefficients strongly depended on antecedent soil moisture content and grazing intensity.

Investigation of permeability of open graded asphalt mixture considering effects of anisotropy and two-dimensional flow

The objective of this study is to investigate the anisotropic effect of permeability and measure permeability of open graded friction course (OGFC) mixtures under the combined horizontal and vertical water flow. The anisotropic effect of permeability of OGFC mixture was investigated using a customized testing method. The ratios of maximum and minimum permeability coefficients were found in the range of 1.4–1.7 for different mixtures. In addition, considerable differences were observed for the permeability measured in the opposite directions with the same water flow path. A special permeameter was developed to measure permeability coefficient and surface runoff coefficient under two-dimensional water flow considering the effect of rainfall intensity and transverse cross slopes. The testing results show that the permeability of OGFC mixture is affected by rainfall intensity and transverse cross slope in addition to the air voids. These factors affect the effective air voids available for water flow and thus water saturation level in the OGFC mixture. The results indicate that the traditional one-direction flow method may not be adequate to accurately evaluate the permeability of asphalt mixtures with large air voids.

Evaluation of soil erosion rates in the southern half of the Russian Plain: methodology and initial results

Abstract. The Russian Plain (RP) is divided into two principally different parts. The northern half of the RP is a predominantly forested area with a low proportion of arable fields. In contrast, the southern half of the RP has a very high proportion of arable land. During the last 30 years, this agricultural region of the RP has experienced considerable land use transformation and changes in precipitation due to climate change have altered soil erosion rates. This paper describes the use of erosion model calculations and GIS spatial analytical methods for the evaluation of trends in erosion rates in the RP. Climate change (RIHMI World Data Center, 2016), land use transformation and crop rotation modification (Rosstat, 2016; R Core Team, 2016) are the main factors governing erosion rates in the region during recent decades. It was determined that mean annual erosion rates have decreased from 7.3 to 4.1 t ha−1 yr−1 in the forest zone mostly because of the serious reduction in the surface runoff coefficient for periods of snowmelt. At the same time, the erosion rates have increased from 3.9 to 4.6 t ha−1 yr−1 in the steppe zone due to the increasing frequency of heavy rain-storms.

Surface runoff estimation from various land use in Mapili Watershed using SCS Curve Number and Geographic Information System

Mapili watershed which is located in West Sulawesi is dominated by secondary forest and agriculture land. The condition of the watershed is affected by land use and soil type. Land use is a form of interaction between man and land in order to meet their needs. Soil is function from organism, climate, topographic, material, and time. This information then will affect the hydrological condition in the watershed, especially surface runoff. The objective of study is to analyze the surface runoff in Mapili watershed. SCS curve number method that integrates with geographic information system was used in the analysis. The highest surface runoff value is about 887.6 mm and the highest of surface runoff coefficient is about 0.31.

Spatial evaluation of impacts of increase in impervious surface area on SCS-CN and runoff in Nagpur urban watersheds, India

The changing land use due to rapid urbanization has profound impact on the runoff in urban watersheds. The spatial analysis in urban watersheds is felt necessary for management of surface and subsurface water regimes. Significant increase in impervious zones was observed in Nagpur urban watersheds between 2000 and 2012 having impacts on runoff, and even flash floods were observed. This study presents spatial and temporal impacts of change in urban built-up area on curve number (CN) and runoff during the years 2000 and 2012. The study also analyzes effect of slope on CN values and shows that CN increases with slope. High-resolution satellite images were used to map impervious surface areas (ISAs) which show an increase of 0.9 to 34 % during 2000–2012. Spearman’s and Pearson’s coefficients have been generated to establish relationship between runoff, impervious surface areas, vegetation index, slope, and runoff coefficient. It has been hypothetically assumed that if 100, 50, and 25 % rooftop rainwater harvesting is considered, the estimated runoff reduces in 2012 as compared to the year 2000. The study suggests that increase in impervious areas within urban watersheds can be utilized for groundwater augmentation adopting rooftop rainwater-harvesting techniques and to prevent flash floods.

Characteristics of the surface–subsurface flow generation and sediment yield to the rainfall regime and land-cover by long-term in-situ observation in the red soil region, Southern China

Land cover and rainfall regime are two important factors that affect soil erosion. In this paper, three land cover types – grass cover, litter cover and bare land – were employed to analyze surface runoff, subsurface flow and sediment loss processes in relation to the rainfall regimes in the red soil region of China. Five rainfall regimes were classified according to 393 rainfall events via a k-means clustering method based on the rainfall depth, duration and maximum 30-min intensity. The highest surface runoff coefficient and erosion amount were found on bare land in all five rainfall regimes, and the lowest were found on grass cover. The litter cover generated the highest subsurface flow rate, followed by the grass cover; the lowest was on bare land. For grass cover and litter cover plots, rainfall events of rainfall regime IV which had the longest duration, greatest depth and lowest intensity had the highest surface runoff coefficient, soil erosion amount and subsurface flow rate. For bare land, storm rainfall events of rainfall regime V had the highest intensity, lowest depth and duration, had the highest surface runoff coefficient and soil erosion amount, but the lowest subsurface flow rate. The highest subsurface flow rate of bare land happened in rainfall regime IV. Surface cover was urgently needed to reduce soil erosion. When the lands under dense surface cover, more attention should be paid to rainfall events that of long duration, high depth but low in intensity which commonly occurred in spring. The interactions of surface–subsurface flow and its effects on soil erosion and nutrient loss were worth considering in the red soil region.