scholarly journals Scaling Effects of Elevation Data on Urban Nonpoint Source Pollution Simulations

Entropy ◽  
2019 ◽  
Vol 21 (1) ◽  
pp. 53
Author(s):  
Ying Dai ◽  
Lei Chen ◽  
Pu Zhang ◽  
Yuechen Xiao ◽  
Zhenyao Shen
Keyword(s):  
Scale Effects ◽  
Model Performance ◽  
Nonpoint Source ◽  
Entropy Method ◽  
Scaling Effects ◽  
Urban Catchment ◽  
Nps Pollution ◽  
Elevation Data ◽  
Urban Catchments ◽  
Natural Watersheds

The scale effects of digital elevation models (DEM) on hydrology and nonpoint source (NPS) pollution simulations have been widely reported for natural watersheds but seldom studied for urban catchments. In this study, the scale effect of DEM data on the rainfall-runoff and NPS pollution was studied in a typical urban catchment in China. Models were constructed based on the DEM data of nine different resolutions. The conventional model performance indicators and the information entropy method were applied together to evaluate the scale effects. Based on the results, scaling effects and a resolution threshold of DEM data exist for urban NPS pollution simulations. Compared with natural watersheds, the urban NPS pollution simulations were primarily affected by the local terrain due to the overall flat terrain and dense sewer inlet distribution. The overland process simulation responded more sensitively than the catchment outlet, showing prolonged times of concentration for impervious areas with decreasing DEM resolution. The diverse spatial distributions and accumulation magnitudes of pollutants could lead to different simulation responses to scaling effects. This paper provides information about the specific characteristics of the scale effects of DEM data in a typical urban catchment, and these results can be extrapolated to other similar catchments as a reference for data collection.

scholarly journals Optimal allocation of nonpoint source pollution control measures using two modern comprehensive evaluation methods

Water Policy ◽  
2018 ◽  
Vol 20 (4) ◽  
pp. 811-825
Author(s):  
Lei Wu ◽  
Xiaodan Tang ◽  
Xiaoyi Ma
Keyword(s):  
Pollution Control ◽  
Optimal Allocation ◽  
Comprehensive Evaluation ◽  
Fuzzy Comprehensive Evaluation ◽  
Nonpoint Source ◽  
Control Measures ◽  
Nutrient Loss ◽  
Vegetative Filter Strips ◽  
Filter Strips ◽  
Nps Pollution

Abstract Nonpoint source (NPS) pollution has been studied for many years but it exhibits random, widespread, complex uncertainties which make it difficult to manage and control. We employ group decision-making utilizing the fuzzy comprehensive evaluation method (FCE) and the analytic hierarchy process method (AHP) and comparatively evaluate the optimal allocation of NPS pollution control measures. Here, we present the top-three evaluation results ranked as follows: combination of contour tillage and vegetative filter strips (CT & VFS), vegetative filter strips (VFS), and combination of contour tillage and fertilizer reduction and vegetative filter strips (CT & FR & VFS). The fourth, fifth and sixth results by FCE method are chemical fertilizer reduction (FR), returning farmland to forest or pasture (RF), and combination of contour tillage and fertilizer reduction (CT & FR), while the corresponding results by AHP method are returning farmland to forest or pasture (RF), combination of contour tillage and fertilizer reduction (CT & FR), and fertilizer reduction (FR). The seventh results for each of the two methods are contour tillage (CT), which has a positive but limited effect on nutrient loss reduction. Our results provide new underlying insights needed to guide the resonable allocation of NPS pollution control measures.

scholarly journals Developing a Reliability Index of Low Impact Development for Urban Areas

Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2961
Author(s):  
Yang Ho Song ◽  
Jung Ho Lee ◽  
Eui Hoon Lee
Keyword(s):  
Urban Areas ◽  
Distance Measure ◽  
Low Impact Development ◽  
Drainage System ◽  
Reliability Evaluation ◽  
Nonpoint Source ◽  
Evaluation Technique ◽  
Storm Water Management Model ◽  
Primary Reference ◽  
Urban Catchments

A defining characteristic of the urbanization is the transformation of existing pervious areas into impervious areas during development. This leads to numerous hydrologic and environmental problems such as an increase in surface runoff due to excess rainfall, flooding, the deterioration of water quality, and an increase in nonpoint source pollution. Several studies propose supplementary measures on environmental change problems in development areas using the low impact development technique. This study investigated the reduction of nonpoint source pollutant loads and flooding in catchments through urban catchment rainfall–runoff management. For the quantitative assessment of flood disasters and water pollution problems, we propose a reliability evaluation technique. This technique refers to a series of analysis methods that determine the disaster prevention performance of the existing systems. As the two factors involve physical quantities of different dimensions, a reliability evaluation technique was developed using the distance measure method. Using the storm water management model, multiple scenarios based on synthetic rainfall in the catchment of the Daerim 2 rainwater pumping station in Seoul, South Korea, were examined. Our results indicate the need for efficient management of natural disaster risks that may occur in urban catchments. Moreover, this study can be used as a primary reference for setting a significant reduction target and facilitating accurate decision making concerning urban drainage system management.

Ecological revetments for enhanced interception of nonpoint source pollutants: a review

2020 ◽  
Vol 28 (3) ◽  
pp. 262-268
Author(s):  
Pengcheng Wang ◽  
Jiaqi Ding ◽  
Yan He ◽  
Difang Wang ◽  
Chengjin Cao ◽  
...  
Keyword(s):  
Pollution Control ◽  
Riparian Zone ◽  
Terrestrial Ecosystems ◽  
Optimization Methods ◽  
Transitional Zone ◽  
Nonpoint Source ◽  
Effective Control ◽  
Future Research ◽  
Nps Pollution ◽  
Nonpoint Source Pollutants

The riparian zone is a transitional zone between aquatic and terrestrial ecosystems and is also the only passage for surface runoff to enter a river. The role of the riparian zone as a means for intercepting nonpoint source (NPS) pollution has been receiving growing attention and, in recent years, various ecological revetments have been developed to strengthen the interception of runoff pollutants. This research reviews the current development of ecological revetments in terms of NPS pollution control with a focus on the key functions and optimization methods of vegetation allocation and substrate configuration. Future research on improving the ecological revetments for enhanced NPS pollution control are also highlighted. This review is intended to provide a technical reference for the optimization and implementation of ecological revetment projects, and possible pathways for the effective control of NPS pollution.

scholarly journals Review of Watershed-Scale Water Quality and Nonpoint Source Pollution Models

Geosciences ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 25 ◽  
Author(s):  
Lifeng Yuan ◽  
Tadesse Sinshaw ◽  
Kenneth J. Forshay
Keyword(s):  
Water Quality ◽  
Model Selection ◽  
Nonpoint Source Pollution ◽  
Assessment Tool ◽  
Nonpoint Source ◽  
Screening Tools ◽  
Simulation Program ◽  
Management Model ◽  
Watershed Scale ◽  
Nps Pollution

Watershed-scale nonpoint source (NPS) pollution models have become important tools to understand, evaluate, and predict the negative impacts of NPS pollution on water quality. Today, there are many NPS models available for users. However, different types of models possess different form and structure as well as complexity of computation. It is difficult for users to select an appropriate model for a specific application without a clear understanding of the limitations or strengths for each model or tool. This review evaluates 14 more commonly used watershed-scale NPS pollution models to explain how and when the application of these different models are appropriate for a given effort. The models that are assessed have a wide range of capacities that include simple models used as rapid screening tools (e.g., Long-Term Hydrologic Impact Assessment (L-THIA) and Nonpoint Source Pollution and Erosion Comparison Tool (N-SPECT/OpenNSPECT)), medium-complexity models that require detail data input and limited calibration (e.g., Generalized Watershed Loading Function (GWLF), Loading Simulation Program C (LSPC), Source Loading and Management Model (SLAMM), and Watershed Analysis Risk Management Frame (WARMF)), complex models that provide sophisticated simulation for NPS pollution processes with intensive data and rigorous calibration (e.g., Agricultural Nonpoint Source pollution model (AGNPS/AnnAGNPS), Soil and Water Assessment Tool (SWAT), Stormwater Management Model (SWMM), and Hydrologic Simulation Program Fortran (HSPF)), and modeling systems that integrate various sub-models and tools, and contain the highest complexity to solve all phases of hydrologic, hydraulic, and chemical dynamic processes (e.g., Automated Geospatial Watershed Assessment Tool (AGWA), Better Assessment Science Integrating Point and Nonpoint Sources (BASINS) and Watershed Modeling System (WMS)). This assessment includes model intended use, components or capabilities, suitable land-use type, input parameter type, spatial and temporal scale, simulated pollutants, strengths and limitations, and software availability. Understanding the strengths and weaknesses of each watershed-scale NPS model will lead to better model selection for suitability and help to avoid misinterpretation or misapplication in practice. The article further explains the crucial criteria for model selection, including spatial and temporal considerations, calibration and validation, uncertainty analysis, and future research direction of NPS pollution models. The goal of this work is to provide accurate and concise insight for watershed managers and planners to select the best-suited model to reduce the harm of NPS pollution to watershed ecosystems.

scholarly journals A Semi-distributed Model for Predicting Faecal Coliform in Urban Stormwater by Integrating SWMM and MOPUS

2019 ◽  
Vol 16 (5) ◽  
pp. 847 ◽  
Author(s):  
Xiaoshu Hou ◽  
Lei Chen ◽  
Jiali Qiu ◽  
Yali Zhang ◽  
Zhenyao Shen
Keyword(s):  
Model Simulation ◽  
Model Performance ◽  
Faecal Coliform ◽  
Distributed Model ◽  
Urban Stormwater ◽  
Management Planning ◽  
Comparable Performance ◽  
Urban Catchments ◽  
Simulation Results ◽  
Swmm Model

The microbial contamination of urban stormwater has an important impact on human health and stormwater reuse. This study develops an exploratory semi-distributed model, MOPUS_S, which can simulate faecal coliform levels in separate sewer systems in urban catchments. The MOPUS_S was built by coupling the SWMM model and the microbial MOPUS model. The parameters associated with the deposition and wash-off of microorganisms were more influential than those related to microorganism survival processes. Compared to other existing bacterial models, MOPUS_S showed comparable performance in predicting faecal coliform concentrations. The performance varied largely between rainfall events, with Nash-Sutcliffe efficiency (NSE) values ranging from −5.03 to 0.39 and R2 ranging from −0.02 to 0.83, respectively. The model simulation results for low and medium concentrations were better than those for the peak concentrations. Poor simulation results of peak concentrations obviously affect the overall model performance. In general, MOPUS_S could be capable of predicting the faecal coliform load in urban catchments and be a useful tool for urban stormwater management planning.

Technical Guidance for Implementing BMPs in the Coastal Zone

1993 ◽  
Vol 28 (3-5) ◽  
pp. 129-135 ◽  
Author(s):  
R. E. Frederick ◽  
S. A. Dressing
Keyword(s):  
Coastal Zone ◽  
Best Management Practices ◽  
Local Governments ◽  
Management Practices ◽  
Technical Assistance ◽  
Nonpoint Source ◽  
Nonpoint Pollution ◽  
Nps Pollution ◽  
Management Measures ◽  
Technical Guidance

The U.S. Environmental Protection Agency (EPA) and the National Oceanic and Atmospheric Administration (NOAA) released the Guidance Specifying Management Measures for Sources of Nonpoint Pollution in Coastal Waters on January 14, 1993. This document is EPA's technical guidance on the best affordable ways to reduce or prevent nonpoint source (NPS) pollution in the coastal zone. The authors believe that it is currently the most comprehensive summary of best management practices (BMPs) available. The guidance contains BMPs for the control of NPS pollution from agriculture, forestry, urban areas, marinas, and hydromodification (channels, dams, and stream and shoreline erosion). Wetlands, riparian areas, and vegetated treatment systems are addressed in the guidance as additional options to control nonpoint pollution. The guidance also includes monitoring and compliance tracking techniques to accompany the management measures. EPA and NOAA are developing approaches to help states, local governments, and affected parties understand and use the technical guidance in their coastal nonpoint source programs. Although final decisions have not yet been made, this paper summarizes the current thinking regarding this technical assistance.

scholarly journals Scale effect challenges in urban hydrology highlighted with a distributed hydrological model

2018 ◽  
Vol 22 (1) ◽  
pp. 331-350 ◽  
Author(s):  
Abdellah Ichiba ◽  
Auguste Gires ◽  
Ioulia Tchiguirinskaia ◽  
Daniel Schertzer ◽  
Philippe Bompard ◽  
...  
Keyword(s):  
Scale Effect ◽  
Hydrological Model ◽  
Scale Effects ◽  
Model Performance ◽  
Scale Dependence ◽  
Urban Hydrology ◽  
Distributed Data ◽  
Hydrological Models ◽  
Multi Scale ◽  
Scale Modelling

Abstract. Hydrological models are extensively used in urban water management, development and evaluation of future scenarios and research activities. There is a growing interest in the development of fully distributed and grid-based models. However, some complex questions related to scale effects are not yet fully understood and still remain open issues in urban hydrology. In this paper we propose a two-step investigation framework to illustrate the extent of scale effects in urban hydrology. First, fractal tools are used to highlight the scale dependence observed within distributed data input into urban hydrological models. Then an intensive multi-scale modelling work is carried out to understand scale effects on hydrological model performance. Investigations are conducted using a fully distributed and physically based model, Multi-Hydro, developed at Ecole des Ponts ParisTech. The model is implemented at 17 spatial resolutions ranging from 100 to 5 m. Results clearly exhibit scale effect challenges in urban hydrology modelling. The applicability of fractal concepts highlights the scale dependence observed within distributed data. Patterns of geophysical data change when the size of the observation pixel changes. The multi-scale modelling investigation confirms scale effects on hydrological model performance. Results are analysed over three ranges of scales identified in the fractal analysis and confirmed through modelling. This work also discusses some remaining issues in urban hydrology modelling related to the availability of high-quality data at high resolutions, and model numerical instabilities as well as the computation time requirements. The main findings of this paper enable a replacement of traditional methods of “model calibration” by innovative methods of “model resolution alteration” based on the spatial data variability and scaling of flows in urban hydrology.

scholarly journals Improved estimation of flood parameters by combining space based SAR data with very high resolution digital elevation data

2009 ◽  
Vol 13 (5) ◽  
pp. 567-576 ◽  
Author(s):  
H. Zwenzner ◽  
S. Voigt
Keyword(s):  
High Resolution ◽  
Flood Mapping ◽  
Scaling Effects ◽  
Data Set ◽  
Digital Elevation ◽  
Geometric Precision ◽  
Elevation Data ◽  
Lidar Dem ◽  
Sar Data ◽  
Very High

Abstract. Severe flood events turned out to be the most devastating catastrophes for Europe's population, economy and environment during the past decades. The total loss caused by the August 2002 flood is estimated to be 10 billion Euros for Germany alone. Due to their capability to present a synoptic view of the spatial extent of floods, remote sensing technology, and especially synthetic aperture radar (SAR) systems, have been successfully applied for flood mapping and monitoring applications. However, the quality and accuracy of the flood masks and derived flood parameters always depends on the scale and the geometric precision of the original data as well as on the classification accuracy of the derived data products. The incorporation of auxiliary information such as elevation data can help to improve the plausibility and reliability of the derived flood masks as well as higher level products. This paper presents methods to improve the matching of flood masks with very high resolution digital elevation models as derived from LiDAR measurements for example. In the following, a cross section approach is presented that allows the dynamic fitting of the position of flood mask profiles according to the underlying terrain information from the DEM. This approach is tested in two study areas, using different input data sets. The first test area is part of the Elbe River (Germany) where flood masks derived from Radarsat-1 and IKONOS during the 2002 flood are used in combination with a LiDAR DEM of 1 m spatial resolution. The other test data set is located on the River Severn (UK) and flood masks derived from the TerraSAR-X satellite and aerial photos acquired during the 2007 flood are used in combination with a LiDAR DEM of 2 m pixel spacing. By means of these two examples the performance of the matching technique and the scaling effects are analysed and discussed. Furthermore, the systematic flood mapping capability of the different imaging systems are examined. It could be shown that the combination of high resolution SAR data and LiDAR DEM allows the derivation of higher level flood parameters such as flood depth estimates, as presented for the Severn area. Finally, the potential and the constraints of the approach are evaluated and discussed.

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