Implementation of Low Impact Development Concept for New Town Construction in the Republic of Korea

2013 ◽  
Vol 742 ◽  
pp. 30-33 ◽  
Author(s):  
Ree Ho Kim ◽  
Jung Hun Lee ◽  
Mik Yeong Kim ◽  
Hyun Dong Lee
Keyword(s):  
Urban Areas ◽  
Hydrological Cycle ◽  
Low Impact Development ◽  
Development Planning ◽  
Ecosystem Functions ◽  
Natural Ecosystem ◽  
Urban Flood ◽  
Flow Control Devices ◽  
The Republic ◽  
Storm Drain

New approach in stormwater management is urgent to address those water related problems and supplement the limitations of existed water management system. It should have functions to restore water and heat cycles in urban areas, that is, to restore hydrological cycle by promoting infiltration and evaporation, to secure water resources, to alleviate heat island phenomena, to prevent urban flood, and to conserve and restore the ecosystem. LID practices are one of prominent measures to mitigate the impacts of development and urbanization. It is important to have a LID approach in the step of site development planning. LID facilities could be categorized as flow control devices, detention, retention, vegetated filtration, infiltration and treatment. LID emphasizes local, decentralized solutions that capitalize on the beneficial services that natural ecosystem functions can provide. LID also focuses on controlling urban runoff and pollution right at the source, rather than at the end of the storm drain outlet. Since there are many different aspects of LID approach, the policy to promote or regulate LID should consider water, energy and ecology conservation.

A new methodology for surcharge risk management in urban areas (case study: Gonbad-e-Kavus city)

2016 ◽  
Vol 75 (4) ◽  
pp. 823-832 ◽  
Author(s):  
Farhad Hooshyaripor ◽  
Jafar Yazdi
Keyword(s):  
Urban Areas ◽  
Pareto Front ◽  
Low Impact Development ◽  
Optimal Solution ◽  
Curve Number ◽  
Hydrologic Model ◽  
Storm Event ◽  
Nsga Ii ◽  
Urban Flood ◽  
Conflicting Objectives

This research presents a simulation-optimization model for urban flood mitigation integrating Non-dominated Sorting Genetic Algorithm (NSGA-II) with Storm Water Management Model (SWMM) hydraulic model under a curve number-based hydrologic model of low impact development technologies in Gonbad-e-Kavus, a small city in the north of Iran. In the developed model, the best performance of the system relies on the optimal layout and capacity of retention ponds over the study area in order to reduce surcharge from the manholes underlying a set of storm event loads, while the available investment plays a restricting role. Thus, there is a multi-objective optimization problem with two conflicting objectives solved successfully by NSGA-II to find a set of optimal solutions known as the Pareto front. In order to analyze the results, a new factor, investment priority index (IPI), is defined which shows the risk of surcharging over the network and priority of the mitigation actions. The IPI is calculated using the probability of pond selection for candidate locations and average depth of the ponds in all Pareto front solutions. The IPI can help the decision makers to arrange a long-term progressive plan with the priority of high-risk areas when an optimal solution has been selected.

scholarly journals An Exploratory Optimal Framework of Low Impact Development Measures Spatial Arrangement based on Source Tracking for Urban Flood Mitigation

2021 ◽  
Author(s):  
Wenchao Qi ◽  
Chao Ma ◽  
Hongshi Xu ◽  
Zifan Chen ◽  
Kai Zhao ◽  
...  
Keyword(s):  
Urban Areas ◽  
Flood Hazard ◽  
Low Impact Development ◽  
Spatial Arrangement ◽  
Source Tracking ◽  
Urban Flood ◽  
Tracking Method ◽  
Source Areas ◽  
Optimization Framework ◽  
Flood Source

Abstract Urban areas are vulnerable to flooding as a result of climate change and population growth and thus rainstorm-induced flood losses are becoming increasingly severe. Low impact development (LID) measures are a storm management technique designed for controlling runoff in urban areas, which is critical for solving urban flood hazard. Therefore, this study developed an exploratory simulation-optimization framework for the spatial arrangement of LID measures. The proposed framework begins by applying a numerical model to simulate hydrological and hydrodynamic processes during a storm event, and the urban flood model coupled with the source tracking method was then used to identify the flood source areas. Next, based on source tracking data, the LID investment in each subcatchment was determined using the inundation volume contribution ratio of the flood source area (where most of the investment is required) to the flood hazard area (where most of the flooding occurs). Finally, the resiliency and sustainability of different LID scenarios were evaluated using several different storm events in order to provide suggestions for flooding predictions and the decision-making process. The results of this study emphasized the importance of flood source control. Furthermore, to quantitatively evaluate the impact of inundation volume transport between subcatchments on the effectiveness of LID measures, a regional relevance index (RI) was proposed to analyze the spatial connectivity between different regions. The simulation-optimization framework was applied to Haikou City, China, wherein the results indicated that LID measures in a spatial arrangement based on the source tracking method are a robust and resilient solution to flood mitigation. This study demonstrates the novelty of combining the source tracking method and highlights the spatial connectivity between flood source areas and flood hazard areas. Further, the framework acts as a strategic tool for the effective spatial arrangement design of LID measures.

scholarly journals Sustainability of the Public Water Supply and Sewerage Services Operating System: A Case Study on the Example of the Czech Republic

2016 ◽  
Vol 47 (1) ◽  
pp. 32-39 ◽  
Author(s):  
M. Hájek ◽  
L. Petružela
Keyword(s):  
Czech Republic ◽  
Water Supply ◽  
Hydrological Cycle ◽  
State Regulation ◽  
Ecosystem Functions ◽  
Public Water Supply ◽  
Natural Ecosystem ◽  
Water Services ◽  
The Czech Republic ◽  
Environmental Objectives

Abstract Water services, as a necessity for natural ecosystem functions and a key output from public governance, play a crucial role in forming sustainable relationships between natural, economic, and social factors in the development of society. Primarily, these relationships relate to the natural impacts of weather and climate on the variability of the hydrological cycle. Secondary relationships exist between providers and consumers of the services. Services provided by operators of public water supply and sewerage systems are a specific segment of water services. Their sustainability is controlled on the one hand by public regulation and and on the other by a combination of economic, social, and environmental objectives and the means by which they are achieved. The aim of this paper is, based on the parameters of supply and demand, to quantify the most important aspects of sustainable management of water supply and sanitation enterprises in connection with the current model for state regulation. The methodology is based on an examination of consumer behaviour indicators which can be interpreted from ‘water bills’. The comparison of household expenditure on water services in the Czech Republic shows that some are already approaching, and even exceeding, the limit of what is considered social acceptability.

scholarly journals ‘Back to the Future’—Oak wood-pasture for wildfire prevention in the Mediterranean

2021 ◽  
Vol 58 (2) ◽  
pp. 41-48
Author(s):  
Erwin Bergmeier ◽  
Jorge Capelo ◽  
Romeo Di Pietro ◽  
Riccardo Guarino ◽  
Ali Kavgacı ◽  
...  
Keyword(s):  
Urban Areas ◽  
Forest Policy ◽  
Coniferous Forest ◽  
Development Planning ◽  
Land Abandonment ◽  
Natural Ecosystem ◽  
Multiple Use ◽  
Tree Species Composition ◽  
Wood Pasture ◽  
The Mediterranean

In the summer of 2021, enormous wildfires in the Mediterranean eliminated huge areas of mainly coniferous forest, destroyed adjacent settlements and claimed the lives of many people. The fires indicate effects of climate change and expose consequences of rural demographic changes, deficits in regional and touristic development planning and shortcomings in forest policy. This forum article highlights the dimensions of the problem, calls for a paradigm shift and shows solutions. Land abandonment, woody plant encroachment and non-reflective afforestation are leading to increasing amounts of combustible biomass. To prevent disastrous fires in future, fundamental changes in tree species composition, forest structure and management are essential. Plantations of reseeding pines are to be substituted by spacious or periodically open woodlands of long-lived trees with resprouting capacity such as Mediterranean oaks. Biomass-reducing practices including wood-pasture have to be revived in rural and peri-urban areas. Exemplary fire-resistant multifunctional oak woodlands occur throughout the Mediterranean. Urgent and medium-term measures in the burnt areas include promoting natural ecosystem regeneration, developing regionalized seed banks and nurseries to support native genetic resources, fostering vegetation mosaics of groves and multiple-use open and coppice woodland maintained by traditional practices, and in general forest management aiming at fuel biomass reduction and a policy counteracting land abandonment.

scholarly journals Predicting Accurate Urban Flooding from Nuisance Flows to Major Disasters

10.29007/81mt ◽  
2018 ◽  
Author(s):  
Noemi Gonzalez-Ramirez ◽  
Fernando Nardi ◽  
James S. O'Brien
Keyword(s):  
Surface Water ◽  
Urban Areas ◽  
Flood Hazard ◽  
Water Flooding ◽  
System Capacity ◽  
Urban Flooding ◽  
Urban Flood ◽  
Building Roof ◽  
Building Collapse ◽  
Storm Drain

Two-dimensional flood models are becoming increasing more accurate in simulating surface water flooding. Concurrently flood hazard maps have higher resolution to support flood mitigation planning. Most flood studies focus on large river flooding (~ 100-yr flood), but in urban areas, emergency access and evacuation routes are needed for frequent rainfall and flood events (< 10-yr return periods). Urban flooding is more complex than river margin flooding and requires significantly more model detail to accurate access risk and hazard for frequent storms. Urban flooding is an event characterized by its frequent repetitive and systematic impact on population and urban infrastructure. Detailed urban flood inundation is now being performed with spatially and temporally variable rainfall and infiltration, channel and street flow, hydraulic structures, surface water storm drain exchange, building loss of storage and flow obstruction, building collapse, levee/wall overtopping and collapse, groundwater flow, sediment scour/deposition and mudflows. In residential neighborhoods, shallow flooding is controlled by streets, buildings, walls and storm drain facilities. Several flood model details and their impact on shallow flooding are discussed including spatially variable storm intensities on pervious and impervious surfaces, surface water exchange with limited storm drain system capacity, and building roof runoff. Several predictive strategies are highlighted to simulate flooding from nuisance flows to major disasters.

scholarly journals An Optimized Approach for Extracting Urban Land Based on Log-Transformed DMSP-OLS Nighttime Light, NDVI, and NDWI

2021 ◽  
Vol 13 (4) ◽  
pp. 766
Author(s):  
Yuanmao Zheng ◽  
Qiang Zhou ◽  
Yuanrong He ◽  
Cuiping Wang ◽  
Xiaorong Wang ◽  
...  
Keyword(s):  
Urban Development ◽  
Urban Areas ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Development Planning ◽  
Urban Land ◽  
Sustainable Urban Development ◽  
Land Use Patterns ◽  
Water Index ◽  
Nighttime Light

Quantitative and accurate urban land information on regional and global scales is urgently required for studying socioeconomic and eco-environmental problems. The spatial distribution of urban land is a significant part of urban development planning, which is vital for optimizing land use patterns and promoting sustainable urban development. Composite nighttime light (NTL) data from the Defense Meteorological Program Operational Line-Scan System (DMSP-OLS) have been proven to be effective for extracting urban land. However, the saturation and blooming within the DMSP-OLS NTL hinder its capacity to provide accurate urban information. This paper proposes an optimized approach that combines NTL with multiple index data to overcome the limitations of extracting urban land based only on NTL data. We combined three sources of data, the DMSP-OLS, the normalized difference vegetation index (NDVI), and the normalized difference water index (NDWI), to establish a novel approach called the vegetation–water-adjusted NTL urban index (VWANUI), which is used to rapidly extract urban land areas on regional and global scales. The results show that the proposed approach reduces the saturation of DMSP-OLS and essentially eliminates blooming effects. Next, we developed regression models based on the normalized DMSP-OLS, the human settlement index (HSI), the vegetation-adjusted NTL urban index (VANUI), and the VWANUI to analyze and estimate urban land areas. The results show that the VWANUI regression model provides the highest performance of all the models tested. To summarize, the VWANUI reduces saturation and blooming, and improves the accuracy with which urban areas are extracted, thereby providing valuable support and decision-making references for designing sustainable urban development.

Housing Finance Reform: Should There Be a Government Guarantee?

2011 ◽  
Vol 01 (04) ◽  
pp. 811-822 ◽  
Author(s):  
Richard K. Green
Keyword(s):  
Rural Areas ◽  
Urban Areas ◽  
The United States ◽  
Economic Stress ◽  
Mortgage Market ◽  
Best Interest ◽  
Finance Reform ◽  
Fixed Rate ◽  
The Great Depression ◽  
The Republic

In 2007 and 2008, the mortgage market failed. It failed in a number of dimensions: Default rates rose to their highest levels since the great depression, and mortgage liquidity ground to a halt. This failure has produced recriminations: Blame has been laid at the feet of borrowers, brokers, lenders, investment banks, investors and government and quasi-government entities that guaranteed mortgages. These recent events have produced an important debate: Whether the U.S. mortgage market requires a federal guarantee in order to best serve consumers, investors and markets. My view is that such a guarantee is necessary. I will divide my argument into four areas: (1) I will argue that the United States has had a history of providing guarantees, either implicit or explicit, regardless of its professed position on the matter. This phenomenon goes back to the origins of the republic. It is in the best interest of the country to acknowledge the existence of such guarantees, and to price them appropriately before, rather than after, they become necessary. (2) I will argue that in times of economic stress, such as now, the absence of government guarantees would lead to an absence of mortgages. (3) I will argue that a purely "private" market would likely not provide a 30 year fixed rate pre-payable mortgage. I think that this is no longer a particularly controversial statement; what is more controversial is whether such a mortgage is necessary — I will argue that it is. (4) I will argue that in the absence of a federal guarantee, the price and quantity of mortgages will vary across geography. In particular, rural areas will have less access to mortgage credit that urban areas, central cities will have less access than suburbs. Condominiums already are treated less favorably than detached houses, and this difference is likely to get larger in the absence of a guarantee.

Effects of riffle–step restoration on hyporheic zone chemistry in N-rich lowland streams

2006 ◽  
Vol 63 (1) ◽  
pp. 120-133 ◽  
Author(s):  
Tamao Kasahara ◽  
Alan R Hill
Keyword(s):  
Urban Areas ◽  
Hyporheic Zone ◽  
Stream Water ◽  
Ion Concentration ◽  
Hyporheic Exchange ◽  
Ecosystem Functions ◽  
Exchange Flow ◽  
Nutrient Inputs ◽  
Lowland Streams ◽  
Hyporheic Zones

Stream restoration projects that aim to rehabilitate ecosystem health have not considered surface–subsurface linkages, although stream water and groundwater interaction has an important role in sustaining stream ecosystem functions. The present study examined the effect of constructed riffles and a step on hyporheic exchange flow and chemistry in restored reaches of several N-rich agricultural and urban streams in southern Ontario. Hydrometric data collected from a network of piezometers and conservative tracer releases indicated that the constructed riffles and steps were effective in inducing hyporheic exchange. However, despite the use of cobbles and boulders in the riffle construction, high stream dissolved oxygen (DO) concentrations were depleted rapidly with depth into the hyporheic zones. Differences between observed and predicted nitrate concentrations based on conservative ion concentration patterns indicated that these hyporheic zones were also nitrate sinks. Zones of low hydraulic conductivity and the occurrence of interstitial fines in the restored cobble-boulder layers suggest that siltation and clogging of the streambed may reduce the downwelling of oxygen- and nitrate-rich stream water. Increases in streambed DO levels and enhancement of habitat for hyporheic fauna that result from riffle–step construction projects may only be temporary in streams that receive increased sediment and nutrient inputs from urban areas and croplands.

Bi-directional Coupling of an Unstructured Triangular Meshes-based Integrated Hydrodynamic Model for Heterogeneous Feature-based Urban Flood Simulation

2021 ◽  
Author(s):  
Guoqiang Peng ◽  
Zhuo Zhang ◽  
Tian Zhang ◽  
Zhiyao Song ◽  
Arif Masrur
Keyword(s):  
Water Flow ◽  
Urban Areas ◽  
Overland Flow ◽  
Coupled Model ◽  
Flood Simulation ◽  
Urban Flood ◽  
Essential Condition ◽  
Flow Processes ◽  
Feature Based ◽  
Heterogeneous Feature

Abstract Urban pluvial flash floods have become a matter of widespread concern, as they severely impact people’s lives in urban areas. Hydrological and hydraulic models have been widely used for urban flood management and urban planning. Traditionally, to reduce the complexity of urban flood modelling and simulations, simplification or generalization methods have been used; for example, some models focus on the simulation of overland water flow, and some models focus on the simulation of the water flow in sewer systems. However, the water flow of urban floods includes both overland flow and sewer system flow. The overland flow processes are impacted by many different geographical features in what is an extremely spatially heterogeneous environment. Therefore, this article is based on two widely used models (SWMM and ANUGA) that are coupled to develop a bi-directional method of simulating water flow processes in urban areas. The open source overland flow model uses the unstructured triangular as the spatial discretization scheme. The unstructured triangular-based hydraulic model can be better used to capture the spatial heterogeneity of the urban surfaces. So, the unstructured triangular-based model is an essential condition for heterogeneous feature-based urban flood simulation. The experiments indicate that the proposed coupled model in this article can accurately depict surface waterlogged areas and that the heterogeneous feature-based urban flood model can be used to determine different types of urban flow processes.

Sign in / Sign up

Export Citation Format

Share Document