Papers by Franco Montalto
The overlooked role of New York City urban yards in mitigating and adapting to climate change
Local Environment, 2014
How Are Low Impact Stormwater Control Measures Simulated by Different Computational Models?
World Environmental and Water Resources Congress 2011, 2011
Water Resources Research, 2007
1] Wetland restoration efforts are ongoing in many urban estuaries. In this context the hydrologi... more 1] Wetland restoration efforts are ongoing in many urban estuaries. In this context the hydrologic characteristics of restored wetlands are of paramount importance since the spatially and temporally variable position of the water table and of soil saturation establishes the oxidation state of the substrate, which, in turn, affects the wetland's biogeochemical composition and the biological communities it is capable of supporting. A relatively simple analytical model developed here describes tidal marsh hydrology from creek bank to interior, considering transient drainage, net meteorological inputs, and tidal effects. Given a series of physical and time-dependent inputs, the analytical solution derived predicts the position of the water table at points along a transect perpendicular to a tidal creek. Validation of the model using water table time series data collected along three transects at Piermont Marsh, a tidal wetland on the Hudson River in the New York/ New Jersey Estuary, indicates good general agreement between observations and predictions, although it may not be precise enough for some kinds of ecological applications. A sensitivity analysis on the model indicates that a range of pairs of transmissivity and specific yield values that increase with distance from the creek results in the same spatial and temporal fluctuations in the water table. This equifinality result is discussed as it relates to the predictive capacity of the model presented. Citation: Montalto, F. A., J.-Y. Parlange, and T. S. Steenhuis (2007), A simple model for predicting water table fluctuations in a tidal marsh, Water Resour. Res., 43, W03439,
Decentralised green infrastructure: the importance of stakeholder behaviour in determining spatial and temporal outcomes
Structure and Infrastructure Engineering, 2012
The traditional approaches to resolving urban stormwater problems include costly expansion of col... more The traditional approaches to resolving urban stormwater problems include costly expansion of collections systems and/or creation of in-line storage and treatment capacity. An emerging ‘green’ infrastructure (GI) approach would instead reduce runoff sources. An agent-based model is used to explore the spatiotemporal emergence of rain gardens and green roofs in Point Breeze, a 175 ha neighbourhood in South Philadelphia, PA, under two different scenarios. In the first, household GI adoption rules consider only economic self-interest and the physical compatibility of each GI technology with lot characteristics. In the second scenario, the adoption rules are enhanced based on insights into the possible behaviour of property owners, as intuited by the designers/authors over a two-year period using a variety of empirical methods. In Scenario 2, relevant knowledge and perceptions are transferred to household decision-makers through social networks, and exposure to GI is assumed to diffuse GI innovation. The two scenarios differ in the temporal rate of GI adoption in the neighbourhood at large (greater in Scenario 1), as well as in the spatial influence of early adopters in Scenario 2, underscoring the importance of stakeholder decisions in the ultimate the effectiveness of watershed-scale GI programs.
Wetlands, 2004
The objectives of this paper are to summarize existing knowledge on the hydrologic characteristic... more The objectives of this paper are to summarize existing knowledge on the hydrologic characteristics of tidal marshes in the New York/New Jersey (NY/NJ) Estuary, to document the extensive linkages between hydrology and tidal marsh function, to underline their importance in designing restoration projects, and to identify research needs in this area. Hydrologic processes are responsible for the evolution, inter-and intra-marsh variability, and functional value of tidal marshes. Hydrology also controls the movement of materials and organisms between estuaries, wetlands, uplands, and the atmosphere. The importance of hydrology to tidal marsh function is widely recognized by the scientific community. Hydrologic research in tidal wetlands of the NY/NJ Estuary, however, is lacking. Anthropogenic development activities have resulted in drastic losses of tidal wetland value, and restoration is now finally a priority in many of the region's natural resource management plans. The success of tidal marsh restoration efforts depends on how appropriately hydrologic factors and their interdependencies are recognized and incorporated into design; yet, little guidance about how best to restore tidal marsh hydrology is available. There is a need to document better the hydrologic characteristics of existing and historical tidal wetlands, to improve hydrologic modeling capabilities, and to accompany other ecological investigations in tidal marshes with hydrologic documentation.
Journal of Industrial Ecology, 2012
environmental impact green infrastructure greenhouse gas (GHG) emissions industrial ecology storm... more environmental impact green infrastructure greenhouse gas (GHG) emissions industrial ecology stormwater management urban hydrology
Journal of Hydrology, 2010
The reliability with which harvested rainwater can be used as a means of flushing toilets, irriga... more The reliability with which harvested rainwater can be used as a means of flushing toilets, irrigating gardens, and topping off air-conditioner serving multifamily residential buildings in New York City is assessed using a new rainwater harvesting (RWH) system reliability model. Although demonstrated with a specific case study, the model is portable because it is based on a nonparametric rainfall generation procedure utilizing a bootstrapped markov chain. Precipitation occurrence is simulated using transition probabilities derived for each day of the year based on the historical probability of wet and dry day state changes. Precipitation amounts are selected from a matrix of historical values within a moving 15 day window that is centered on the target day. RWH system reliability is determined for user-specified catchment area and tank volume ranges using precipitation ensembles generated using the described stochastic procedure. The reliability with which NYC backyard gardens can be irrigated and air conditioning units supplied with water harvested from local roofs exceeds 80% and 90%, respectively, for the entire range of catchment areas and tank volumes considered in the analysis. For RWH systems installed on the most commonly occurring rooftop catchment areas found in NYC (51-75 m 2 ), toilet flushing demand can be met with 7-40% reliability, with lower end of the range representing buildings with high flow toilets and no storage elements, and the upper end representing buildings that feature low flow fixtures and storage tanks of up to 5 m 3 . When the reliability curves developed are used to size RWH systems to flush the low flow toilets of all multifamily buildings found a typical residential neighborhood in the Bronx, rooftop runoff inputs to the sewer system are reduced by approximately 28% over an average rainfall year, and potable water demand is reduced by approximately 53%.
Journal of Hydrology, 2006
The topography, hydroperiod, water table, and selected edaphic characteristics are described for ... more The topography, hydroperiod, water table, and selected edaphic characteristics are described for Piermont Marsh, an irregularly flooded tidal marsh in the Hudson River Estuary, New York, USA. Despite variations in microtopography, overall the marsh is flat, and although the observations were conducted at a high point in the Estuary's 18.6 year metonic cycle, its surface was only inundated 10-12 times a month. Observations of spatial differences in the saturated hydraulic conductivity and surface infiltration rates are also discussed. 'Edge' portions of the marsh are characterized by a slightly higher, more uniform, more structured, less organic, and less hydrologically conductive substrate than found in the marsh interior. Preferential flow is facilitated by macropores in the creekbank wall. The water table is close to the marsh surface for a lesser percentage of the lunar month in the marsh 'edge' when compared to the interior, where it is almost always within 10 cm of the surface. The extent to which the spatial variability of these hydrologic characteristics determines the marsh's ability to provide various ecosystem services is also discussed and the implications of these observations on tidal marsh restoration efforts briefly presented. q
Journal of Environmental Engineering, 2006
The most common form of onsite domestic wastewater treatment in the United States is the septic s... more The most common form of onsite domestic wastewater treatment in the United States is the septic system. Although the design of these systems has been well established, no systematic evaluation of septic system performance exists for sloping hardpan soils. In this paper, we develop a simple hydrologic model for assessing the probability of failure for a set of hydrologic conditions, septic loading rates, and soil and landscape parameters that are readily available for sloping soils. To demonstrate the model capabilities, input data for a septic field of a two-person residence in the New York City drinking water basin in the Catskills was utilized. Our analysis showed that the saturated hydraulic conductivity, depth to the impermeable layer, and slope of the drain field are critical parameters to assess in the design and siting of these systems. We concluded that septic systems perform poorly in undulating landscapes where the hydraulic conductivity is low and the impermeable layer is close to the surface. Under prolonged rainfall conditions on these soils, the septic field and downslope field saturate, causing hydraulic failure of the septic system and saturation in the downslope field; as a result, effluent may be routed directly to streams via overland runoff.
Preliminary results of an agent-based simulation featuring the coupled hydrologic and human interactions typical of a rural Ethiopian village
groundwater-conference.uci.edu
ABSTRACT In semi-arid, developing world settings, hydrologic processes relate directly to poverty... more ABSTRACT In semi-arid, developing world settings, hydrologic processes relate directly to poverty reduction, agricultural productivity, gender, and other social issues. Understanding functional interrelationships between hydrologic processes and irrigation and domestic water use can improve the success rate of international aid projects and of achieving the Millennium Development Goals. One approach for evaluating these interrelationships is with coupled models of hydrologic, social, and agricultural systems. This paper presents ...
Development and Calibration of a High Resolution SWMM Model for Simulating the Effects of LID Retrofits on the Outflow Hydrograph of a Dense Urban Watershed
Low Impact Development for Urban Ecosystem and Habitat Protection, 2008
Most urban watershed models developed to comply with various regulatory programs can only be used... more Most urban watershed models developed to comply with various regulatory programs can only be used to approximate LID implementation in their existing configuration. These models were developed in order to simulate flow through the thousands of acres that ...
Accounting For Uncertainty In Determining The Economic Value Of Green Infrastructure Investments
Proceedings of the Water Environment Federation, 2012
ABSTRACT Green Infrastructure (GI) practices attempt to mitigate the impacts of urbanization thro... more ABSTRACT Green Infrastructure (GI) practices attempt to mitigate the impacts of urbanization through water harvesting, infiltration, evapotranspiration, and reuse on a small-scale. Proponents of GI programs for some time have justified their case based on the potential advantages in cost-effectiveness and wider economic benefits compared to conventional ‘grey’ infrastructure. Today, a growing acceptance of GI as an integral part of an overall stormwater management plans has elevated the need to ensure that public programs, especially if they are intended to meet regulatory requirements (e.g. Combined Sewer Overflow (CSO) Long Term Control Plan) meet the objectives.Uncertainties in GI performance, adoption rates, costs, and benefits can have significant implications on whether and where a GI program makes sense for municipalities, water utilities, and watershed managers. The issues are particularly important for programs that include some cost sharing because higher levels of public-supported costs reduce the balance to be paid by private entities and lead to higher rates of adoption.This paper discusses the integration of engineering, economics, and risk analyses in a model for assisting in GI program decision making. Specifically, the paper proposes a methodology for quantifying this uncertainty, allowing decision making to precede with better information and at a confidence the GI program is structured and targeted most effectively. Methods for quantifying uncertainty, producing output (such as the graphic below) and interpretation are discussed along with several applications.
Integrating human, natural and engineered systems and associated paradigms for infrastructure asset management
Proceedings of the Fourth International IABMAS Conference, Seoul, Korea, July 13-17 2008, 2008
Developments in LIDRA 2.0: A Planning Level Assessment of the Cost-Effectiveness of Low Impact Development
World Environmental and Water Resources Congress 2010, 2010
This paper describes the ongoing development of Low‐Impact‐Development Rapid Assessment Model (LI... more This paper describes the ongoing development of Low‐Impact‐Development Rapid Assessment Model (LIDRA), a planning level model for assessing the cost‐effectiveness of low impact development (LID) as a means of reducing runoff and runoff‐related problems in urban watersheds. ...
Risk Analysis Application for Assessing the Cost-Effectiveness of Low Impact Development for CSO Control Using LIDRA
Low Impact Development for Urban Ecosystem and Habitat Protection, 2008
Contrasting Perspectives Regarding Climate Risks and Adaptation Strategies in the New York Metropolitan Area after Superstorm Sandy
Journal of Extreme Events, 2014
Accounting for Uncertainty in Determining Green Infrastructure Cost-Effectiveness
Economic Incentives for Stormwater Control, 2011
Earth Perspectives, 2014
Background: Though the benefits of centralized water systems (e.g. improved publichealth, environ... more Background: Though the benefits of centralized water systems (e.g. improved publichealth, environmental protection, streamlined operations, economy of scale, reliability) are well known, these systems are not always feasible or appropriate. In developing world settings there has been growing interest by infrastructure experts,researchers, and international lending institutions in decentralized means of improving access to drinking water. While decentralized water systems with independent components may be less vulnerable to systemic failures, hazards, and extreme environmental events, centralized water systems are often associated with a higher quality of life. This study investigates stakeholder preferences regarding water infrastructure issues in Leogane, Haiti (population~300,000), a town situated at the epicenter of the January 2010 earthquake. Methods: The methodology included a paper survey, semi-structured interviews, and a participatory workshop.
Engineering Studies, 2014
Participatory engineering has been called for after major catastrophes, yet is often bypassed due... more Participatory engineering has been called for after major catastrophes, yet is often bypassed due to countervailing implementation of 'quick fixes'. While immediate expert-driven solutions may be attractive, in the long-term they may be ineffective and inconsistent with the goals and capacities of local stakeholders. This article discusses the findings of National Science Foundation research by a team of three engineers and one social scientist who visited Haiti twice, four and seven months after the January 2010 earthquake, to investigate community participation in water and sanitation engineering processes in Léogâne. Methods included interviews with local inhabitants, water-sector actors, and government agencies; inspections of the engineering of the existing water and sanitation system; surveys of the affected population; and a participatory workshop to which numerous community-based organizations were invited. The research tests the potential for engineers to develop stakeholder-based participatory processes in a post-disaster context, which is hypothesized to produce better outcomes than traditional top-down authoritative planning processes. Focusing on the sanitation sector within a multi-stakeholder arena, the article analyzes the potential for various kinds of interactions amongst actors during unfolding decision-making processes at multiple scales, and assesses how each might contribute to better post-disaster engineering and ultimately more sustainable water and sanitation systems.
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Papers by Franco Montalto