Evaluation of Costs and Efficiencies of Urban Low Impact Development (LID) Practices on Stormwater Runoff and Soil Erosion in an Urban Watershed Using the Water Erosion Prediction Project (WEPP) Model

Storm events and soil erosion can adversely impact flood control, soil conservation, water quality, the recreation economy, and ecosystem biodiversity in urban systems. Urban Low Impact Development practices (LIDs) can manage stormwater runoff, control soil losses, and improve water quality. The Water Erosion Prediction Project (WEPP) model has been widely applied to assess the responses of hydrology and soil losses to conservation practices in agricultural and forested areas. This research study is the first to calibrate the WEPP model to simulate streamflow discharge in the Brentwood watershed in Austin, Texas and apply the calibrated WEPP model to assess the impacts of LIDs. The costs and impacts of various LID scenarios on annual water balance, and monthly average, and daily runoff volumes, and sediment losses at hillslopes and at the watershed outlet were quantified and compared. The LID scenarios identified that native planting in Critically Eroding Areas (CEAs), native planting in all suitable areas, native planting in CEAs with detention ponds, and native planting in all suitable areas with detention ponds could reduce the predicted average annual stormwater runoff by 20–24% and sediment losses by 86–94% at the watershed outlet, and reduce the average annual soil loss rates on hillslope profiles in sub-watersheds by 86–87% with the lowest costs (USD 2991/yr–USD 5257/yr). Watershed/field characteristics, locations, areas, costs, and the effectiveness of the LID practices were essential in choosing the LID scenarios. These research results can help guide decision-making on the selection and implementation of the most economical and suitable LID practices to strengthen the climate resilience and environmental sustainability of urban systems.

Estimativa da erosão hídrica do solo pelo modelo Water Erosion Prediction Project na Sub-Bacia do Córrego do Gigante, sul de Minas Gerais

RESUMO Objetivou-se, no presente trabalho, monitorar e identificar precipitações erosivas e as perdas de solo (PSs) por meio de parcelas experimentais instaladas na Sub-Bacia do Córrego do Gigante, calibrar o modelo Water Erosion Prediction Project (WEPP) em sua versão encosta, tendo como base os resultados obtidos nas parcelas, e aplicá-lo na área da sub-bacia, para estimativa das PSs por erosão hídrica. O regime pluvial no período de estudo apresentou elevado grau de erosividade e de concentração, pois 57,3% dos eventos foram erosivos, dos quais, os quatro de maior magnitude, participaram com 47,2% da erosividade anual. As áreas contempladas pelas interações entre classe de solo, declividade (D) e uso de solo, nas parcelas experimentais, totalizaram 174,32 ha (50% da área da sub-bacia), cujos valores obtidos resultaram em PS média ponderada de 0,623 t ha-1 ano-1, e foram referência no ajuste do modelo WEPP na versão encosta, com estimativa de 0,651 t ha-1 ano-1. A aplicação do modelo sobre uma superfície com 93,0% de abrangência da sub-bacia resultou em uma estimativa de 0,802 t ha-1 ano-1 para a taxa de PS. As áreas de solo exposto, embora participando com apenas 7,9% da área da sub-bacia, produziram 85,1% das PSs estimadas, o que, por outro lado, reflete a influência positiva da cobertura vegetal na diminuição da erosão hídrica. Simulando a implantação de cobertura sob a forma de campo/pastagem e/ou reflorestamento, nas áreas de solo descoberto, as taxas de PS na sub-bacia reduziriam significativamente para 0,215 t ha-1 ano-1.

Kajian Potensi Erosi Di Daerah Aliran Sungai Babon Menggunakan Permodelan GeoWEPP

At the time of the high intensity of rainfall in Semarang, the water contained in the Babon River had overflowed, resulting in flooding of parts of the area adjacent to the Babon river flow. This matter has many factors, there are erosion and sediment produced. This study aims to study erosion potential in the Babon watershed, using the Geospatial Interface for Water Erosion Prediction Project (GeoWEPP) modeling. The results of the modeling are the amount of erosion rate and erosion distribution in the study area. The erosion prediction period in this study is in 2006 - 2015. Data needed in GeoWEPP operation are Digital Elevation Model, climate data, land use data, and soil type data. Based on the GeoWEPP process in the Babon watershed the erosion rate was 36.1 tons / ha / year and the sediment yield was 26075.2 tons / year. From the results of the erosion rate produced divided by the reasonable erosion rate get the Erosion Hazard Level index (TBE) of 3.6 or including medium TBE. Based on the distribution of erosion maps produced, the area experienced the greatest erosion rate in the Ungaran region. This is due to the fact that it belongs to the highlands and has a high slope value.

Measuring and Predicting Erosion on Sandy Roads to Inform Strategies for Sustainable Transport Network Management: A Case Study of the Great Sandy National Park, Australia

Different surveying methods were used to assess and illustrate road profile changes and sediment displacement over a six-month period at four sites on a sand road at Cooloola, Queensland, Australia. Total monthly traffic and total monthly rainfall (two-way ANOVA without replication, p < 0.05) had an effect on the mean centre dumpy level depths and sediment displacement at one site (correlation 0.81 for total monthly traffic/mean centre dumpy level depths), but not at the other three sites. Traditional road-surface field measurements showed large changes in volume and weight of sediment movement and Water Erosion Prediction Project (WEPP) modelling predicted an annual sediment yield (i.e., sand displacement from road) of 115.37 kg with a total sediment loss of 7,551.36 kg for each 120 m by 6 m site over the next 80 years. The methodology used can be applied to other national parks and protected areas and for the effective and sustainable management of sand road networks.

Predicting plot soil loss by empirical and process-oriented approaches. A review

Soil erosion directly affects the quality of the soil, its agricultural productivity and its biological diversity. Many mathematical models have been developed to estimate plot soil erosion at different temporal scales. At present, empirical soil loss equations and process-oriented models are considered as constituting a complementary suite of models to be chosen to meet the specific user need. In this paper, the Universal Soil Loss Equation and its revised versions are first reviewed. Selected methodologies developed to estimate the factors of the model with the aim to improve the soil loss estimate are described. Then the Water Erosion Prediction Project which represents a process-oriented technology for soil erosion prediction at different spatial scales, is presented. The available criteria to discriminate between acceptable and unacceptable soil loss estimates are subsequently introduced. Finally, some research needs, concerning tests of both empirical and process-oriented models, estimates of the soil loss of given return periods, reliability of soil loss measurements, measurements of rill and gully erosion, and physical models are delineated.

Evaluation of the effects of land consolidation in the Latyczyn village in terms of land protection against erosion on the slope scale

Soil erosion by water is an important economical issue strongly deteriorating environment and requiring remedial actions. The study was designed to evaluate antierosion effect of changes in the layout of plots from along to across slope as an effect of land consolidation. Moreover, rightness of leaving newly set out boundaries of plots without any protection (i.e. sodding) was evaluated. For this purpose simulations of use of additional anti-erosive measures were done. The Water Erosion Prediction Project (WEPP) model was used. Studies have shown that in addition to the design of transverse layout of parcels during consolidation, further antierosion measures may be necessary to reduce soil loss and sediment yield. In order to minimize soil losses outside the slope, boundaries between the newly designed fields should be sodded already in the post consolidation management. Limitation the amount of erosion over the entire slope requires use of additional protection measures in the upper part of slopes e.g. shelterbelts and antierosion crop rotations. WEPP model can be recommended for Provincial Bureaus of Surveying as a tool to support the development of assumptions for consolidation projects of lands threatened by erosion.