Surface Water Drainage Research Articles

Anthropogenic Evolution of Zheltozems in the Sochi Sanatorium Area

The anthropogenic evolution of zheltozems (Acrisols) in the sanatorium zone of the Sochi agglomeration is characterized by a change in the acid-base properties and humus status of soils since the late 1920s. The pHwater shifted from 5.1 to 7.4 (mean values for soil genetic horizons) and the total exchangeable bases increased 2.4 times (from 17.2 to 41.2 cmol(+)/kg) in the topsoil and 1.3 times (from 15.9 to 21.0 cmol(+)/kg) in the structural-metamorphic gleyed BMg horizon. Soil alkalization typical for urban environment resulted in the suppression of eluviation of the upper part of the BMg horizon. Humus content remained at the same level (about 6.7%) in the topsoil, but increased (to 3.6–4.3% as compared to the initial 0.5–0.8%) in the subsoil. This transformation is caused by two factors: (1) the input of technogenic salts of metals with the surface runoff and drainage water, which are alkaline and transform the acid-base soil properties; (2) cultivation of soils (filling of the humus horizon of chernozem onto the soil surface) for planting exotic plants from dendroparks in sanatoriums. The soils are qualified for dark structural-metamorphic agrozems. There are small local areas of abrazems, and soils of subordinate landscapes in the lower parts of slopes adjacent to small streams are represented by chemozems over zheltozems. On steep slopes to the Black Sea coast without sanatorium infrastructure, almost untransformed typical zheltozems are formed under natural vegetation. With an increase in pH as a result of stronger anthropogenic transformation, the base saturation of zheltozems steadily decreases.

Retrospective analysis of urban malaria cases due to Plasmodium falciparum and Plasmodium vivax: the case of Batu town, Oromia, Ethiopia

Malaria is a major health problem in the world particularly in sub-Saharan Africa where 90% of malaria deaths occur. Likewise malaria is one of the leading causes of morbidity and mortality in Ethiopia. It has been reported that about 75% of the country is malarious where 60% of its population is at risk of this infection. Like many African countries, Ethiopian urban settings are characterized by poor housing, lack of sanitation and drainage of surface water which provide conducive environment for the breeding of vector mosquitoes for the transmission of malaria. There are few researches on urban malaria under the urban settings of Ethiopia. The purpose of this study was to assess the magnitude of malaria cases due to Plasmodium falciparum and Plasmodium vivax in Batu town, Oromia, Ethiopia. Retrospective laboratory confirmed malaria case record data of six years (2012–2017) were used to analyze the magnitude of malaria cases due to P. falciparum and P. vivax, in Batu town, Oromia, Ethiopia. The retrospective data analysis revealed an overall 21,797 malaria confirmed cases; of which 49.5% were due to P. falciparum and 50.5% were due to P. vivax, with a slight decline in malaria between 2012 and 2017. Malaria cases were recorded in both sexes and all age groups in the study area. From the result of the present analysis it can be concluded that both P. falciparum and P. vivax were the cause for malaria cases indicating malaria is still public health problem in Batu town. Therefore, appropriate strategic control measures must be designed to protect the public and eventually eliminate malaria from the area and the country as a whole.

Fish market infrastructure in Khulna city, Bangladesh

An investigation was carried out on fish market infrastructure of Khulna district to identify the infrastructure facilities of domestic fish market including species traded along with price and also to detect the constraints at different levels of trading recommending possible solutions according to standards. The investigation was conducted from November 2016 to June 2017 in three different markets of Khulna district namely Sandhya Bazar fish market, Aranghata Bypass Bazar fish market and Baikali Bazar fish market. In Khulna, a large number of people are involved in fish marketing. Market infrastructures of Khulna had grown up according to various influencing factors that controls the total system involved. The study was based on observation and field survey. Data were collected through eye observation, questionnaire interviews and focus group discussions. Several number of market agents including wholesalers, retailers were selected for questionnaire interviews and aratdars and fishermen were selected for focused group discussions. It was revealed that the infrastructure facilities were inadequate and poorly maintained. Fish sheds were not enough hygienic to protect the fish from contamination. Surface water drainage system was open and this situation degraded further environmental condition of the markets. Electricity maintenance was not up to the mark and there were no distillation process for the supplied water. This infrastructural condition does not support a hygienic condition for fish marketing to provide edible and quality fish. Total number of freshwater fish species traded in different markets was found 60 including 12 SIS, 34 culture and 14 capture. On the other hand 41 brackish and marine water species were found and 14 crustacean species of which 5 were freshwater prawn, 6 brackish water shrimp and 3 crabs. Therefore domestic market infrastructure is on a developing stage as being controlled by Khulna City Corporation (KCC). Establishment of ice factory, improvement of fish transport facilities, introduction of fish quality control measures were suggested to improve the fish marketing in the study area.
 Asian Australas. J. Biosci. Biotechnol. 2020, 5 (1), 122-134

Degradation of the Vila Maria Spring in Garanhuns–PE

This research aimed to analyze the degradation of the Vila Maria spring, located in the Magano neighborhood in the municipality of Garanhuns in the state of Pernambuco. The municipality’s terrain is marked by undulated landform, especially hills, which allied to the accelerated rhythm of urban expansion without adequate planning, resulted in the occupation of risk areas such as slopes as well as environmental protection areas such as the adjacencies of springs. The analysis was carried out through a terrain modeling process in a geoprocessing environment and by data collected on visits to the study area. An analysis of the region’s NDVI from years 2008 to 2018 was also performed. The analysis confirmed the Vila Maria spring’s water degradation and found that it was aggravated by an inadequate disposal of rainwater through surface water drains which contributed to the intensification of erosive processes that generated a gully in the vicinity. The NDVI analysis found low average values with an increase from 2008 to 2018 during the wet season. This fact can be explained by the constant urban expansion which as has been utilizing slopes from the microbasin for the disposal of rainwater which allied to the constant flow of the Vila Maria spring, provides a constant supply of water to the vegetation cover. Moreover, it was possible to observe the misuse of the spring’s water flow by the public administration which has most of its flow integrated to the surface water drainage system and it is disposed at the bottom of the slope going through a high risk of contamination.

STRATEGY OF LAND MANAGEMENT AND GEODESIC SURVEYS DURING DESIGN AND CONSTRUCTION OF HIGHWAYS AND RAILWAYS

Purpose. To consider the strategy of land management in the context of determining the boundaries of earthworks during the projecting of highways and railways, in areas requiring the construction of water drain constructions. Explore design techniques in numerical projections. Prove the simplicity and convenience of the above method. Methodology. Using the method of projections with numerical marks, the issues of designing the earth's canvas and drainage facilities are considered. Findings. In the design of roads and railways in areas where it is possible to cross the road surface with superficial waters (in sections of the wells, in areas with a longitudinal slope of more than 3 %, in the places of turns and concave vertical curves in the longitudinal profile, in places of opposite slopes) it is necessary to predict – a system of surface drainage. An example of the creation of drainage cuvettes is given. Originality. The simplicity and ease of use of projections with numerical marks in designing roads is established. The method of construction of drainage cuvettes with removal of them from the eaves of the earth canvas is considered in detail, which is not sufficiently considered in the literature. Practical value. When designing and building roads, the first factors influencing the final result are the quality of geodetic surveys and design work. Therefore, it is important to study the issue of drainage of surface water from the earth's canvas, because the technical solutions adopted in the project should ensure both the safety of traffic and high transport and road performance indicators, as well as the durability of engineering structures with a minimum level of material and financial costs.

Remote sensing and sig contribution for the identification of the fracturation influence on the drainage network architecture in the High Ziz River basin, Central High Atlas, Morocco

Abstract This study aims to contribute to a better estimation of the density of fractures likely to favour the drainage of surface water in the High Ziz River (HZR) basin. The method adopted consists of the use of different airborne image processing techniques (filtering, enhancement and slope analysis) which allow a good discrimination of image discontinuities (lineaments) that can then be used for producing lineament maps. The influence of these lineaments on the underground flow is then studied. Indeed, it was possible to extract the lineament network, following the exploitation of remote sensing and an objectively completed analog analysis using the PCI Geomatica LINE module and its directional filters (Sobel directional filters by the ACP method), and to extract the hydrographic network of the HZR basin, using the ArcHydro tool. After superimposing these data, their thematic maps (of the lineament and hydrographic network) were developed. In addition, this comparison of the two hydrographic networks and lineament maps showed us very varied flow directions influenced by geological structures, particularly fracturing. The topography of the region also has a secondary impact on flows through the presence of slopes generally oriented towards the SE of the basin. The correlation of the results with the different directions of the orders of the hydrographic network allowed us to identify the potential effects of lineaments on the orientations of surface water circulation. In addition to these results, the realization of the Rose diagram indicated that the dominant trend in lineaments is N90–45N° (NE–SW).

Feasibility assessment of the use of basic oxygen furnace slag in open graded asphalt courses

India is the world’s third largest steel producer with a production of 97.8 million tonnes in 2017. Steel slag is obtained as a by-product from steel-making industries during the conversion of iron to steel. Steel slag possesses favorable angularity and strength properties. This study aims to utilize basic oxygen furnace (BOF) steel slag as coarse aggregate for open graded asphalt courses (OGACs). OGAC is a special hot-mix asphalt wearing course that is designed for higher air voids to achieve quick drainage of surface water and better wet weather performance. High air voids in OGAC are created with the use of a higher proportion of uniformly graded coarse aggregates and low amount of fines. In this study, use of BOF slag in OGAC mixes is evaluated through 0% (control mix), 25%, 50%, 75% and 100% replacement of coarse natural aggregate. Further, two types of modified asphalt binders are used: polymer-modified and crumb rubber-modified binder for evaluation of OGAC mixes with and without BOF slag. OGAC mixes are evaluated for volumetric characteristics (bulk density and air voids), stone-on-stone contact, binder draindown, and raveling resistance. Raveling resistance is evaluated through Cantabro abrasion loss test under both unaged and aged conditions. Results of the study indicate that an increase in steel slag content enhances the stone-on-stone contact and improves the resistance to raveling of OGAC mixes. Based on statistical analysis through analysis of variance (ANOVA), binder content and slag replacement percentage are found to have significant influence on the properties of OGAC mixes.

The Design, Construction and Maintenance of a SuDS management Train to Address Surface water Flows by Engaging the Community: Gawilan Refugee Camp, Ninewah Governate, Kurdistan Region of Iraq

AbstractRefugee camps are set up under crisis conditions in the Kurdistan Region of Iraq by the United Nations High Commissioner for Refugees (UNHCR) with Water, Sanitation and Hygiene (WASH) installed as a matter of course. However, in general, little account is taken of surface-water drainage or greywater management until the camp floods or greywater streams become an environmental or health issue. This article reports on the construction of a sustainable drainage systems (SuDS) management train in a refugee camp with the community and local non-governmental organizations to address excess surface water and lack of greywater management in this most challenging of environments. There is thus potential to influence policy, at the first stages of planning, to encourage the installation of drainage as well as WASH. SuDS mimic nature by percolating water into the ground, storing it and allowing slow conveyance to reduce the storm peak, improve water quality and provide space for amenity for residents and for biodiversity. By encouraging the water to infiltrate, polluted standing water between dwellings and on the street is reduced, so that human and environmental health is improved, with the potential to address nuisance-insect-breeding sites. Site walkovers, workshops and meetings engaged residents in the design process from the very beginning. The design produced by the community was professionally drawn up and passed to the UNHCR and local management engineers for comment and approval; this article describes the process of designing and constructing the first SuDS-management train to be built in a humanitarian setting.

Draining Doha: a sustainable approach to water management in an arid region

This paper describes the development of surface water drainage infrastructure to serve Doha, the capital of Qatar, a relatively young and developing city in the Middle East. It discusses the impact of increased urbanisation on flood risk, and the strategies developed and used to provide sustainable drainage systems, and surface and groundwater reuse on a scale not usually seen in a dense urban environment.

Skid resistance and surface water drainage performance of engineered cementitious composites for pavement applications

Engineered Cementitious Composite (ECC) is a unique class of the high performance fiber-reinforced cement-based material showing extreme tensile ductility of several percent. Few studies have reported potential use of ECC for rigid pavement applications. The critical shortcoming of ECC for roadway application is on the surface texture. ECC lacks coarse aggregates, which leads to low skid resistance and surface drainage. In this study, corundum is first incorporated as fine aggregates into ECC mix (ECC-Cor) to improve the surface micro-texture. The resulting ECC-Cor possesses satisfactory mechanical performance and high skid resistance (BPN > 70). ECC-Cor also shows good durability and the micro-textures can last for more than 100,000 load cycles. While the addition of corundum significantly enhances the micro-texture and skid resistance, improvement on macro-texture and surface drainage is marginal. Further surface treatment with grooves successfully improves the functional performance, not only by minimizing the risk of hydroplaning (water outflow time < 4 s) but also by improving the skid resistance (BPN > 90). An empirical model, which correlates water drainage to macro-texture and pavement geometries of ECC, is proposed.

PREPARATIONS FOR REMEDIATION OF A FORMER SURFACE MINE – A TECHNICAL RECLAMATION AREA

The reclamation area for secondary float energy by-products is located on a spoil heap, 45m thick and 30 years old, and consists mostly of clay stone with high plasticity. When depositing a first 18m high stack, it was necessary to verify stability and to analyse deformations during the reclaiming operation. Stability and deformation depend on the shallow groundwater level. Therefore, it was necessary to propose a technical solution for drainage of the structure concerned. This can be divided into two parts: drainage of surface water and drainage of the shallow underground water. It means a complex solution for the entire construction that would not be possible without long-term monitoring of the construction and field mapping. Completion of the proposed facilities will increase the stability of the reclamation area and it will then be possible to continue with remediation of the former surface mine.

Automated Extraction of Drainage Channels and Roads through Deep Learning

Abstract. The National Map provides geospatial data that support various uses such as resource management, disaster response, and science investigations. To properly support these needs, data themes of the National Map must be regularly updated and spatially integrated as the features on the ground change because of environmental or man-made events. The elevation theme of the National Map is managed through the 3D Elevation Program (3DEP), which is currently (2019) coordinating collection of high resolution (HR) elevation data for the United States over an eight-year period (Sugarbaker et al. 2014). Through this program, lidar point-cloud data are being collected for the conterminous United States, Hawaii, and U.S. territories, with coarser resolution interferometric synthetic aperture radar (ifsar) data being collected for the remote areas of Alaska. HR digital elevation models (DEMs) can be generated at 1 and 3 meter resolution from the lidar point-cloud data and are also furnished by 3DEP.This research develops automated methods to update the hydrography and transportation themes of the National Map in a manner that integrates with the HR elevation and image layers. Surface water drainage networks can be extracted from a HR DEM using flow-direction and flow-accumulation modelling, but results of these methods vary depending on environmental conditions and the existence of anthropogenic features that may affect the accuracy of the elevation model, such as vegetative cover, roads, bridges, and other urban structures. Hydrologic conditioning or enforcement of a HR DEM overcome some of these issues and improve flow modelling for drainage network extraction through techniques such as filtering (Passalaqua et al. 2010), filling sinks (Tarboton 1997), cutting channels through embankments at culvert and bridge locations (Poppenga et al. 2012), or burning-in existing streams (Maidment 1996). However, drainage network extraction results can vary substantially with these techniques and the methods generally require some manual intervention and/or tuning of parameters (Poppenga et al. 2013). Consequently, additional work is needed to streamline and further automate such methods for the various landscape conditions within the United States.

A retrospective analysis on the transmission of Plasmodium falciparum and Plasmodium vivax: the case of Adama City, East Shoa Zone, Oromia, Ethiopia

BackgroundMalaria is more often considered a problem of the rural poor and the disease has been overlooked in urban settings for centuries due to the assumption that economic development in urban areas results in better life conditions, such as improved housing, drainage system and environmental changes that makes urban areas not conducive for breeding of the malaria vector. But, for many African countries, including Ethiopia, in most urban areas, although there are rapid developments, they are characterized by poor housing, lack of sanitation and drainage of surface water that would provide favourable conditions for vector breeding. Limited studies have been conducted as far as urban malaria is concerned in Ethiopia. The purpose of this study was to assess the status of falciparum and vivax malaria transmission in Adama City, Eastern Shoa Zone, Oromia, Ethiopia. Understanding the local epidemiology of malaria will help policy makers and other stakeholders to design and implement tailored cost effective and efficient intervention strategies targeting urban malaria.MethodsThe study was designed to analyse 5-year trends of malaria burden by two co-endemic species in Ethiopia (Plasmodium falciparum and Plasmodium vivax) and its annual and seasonal transmission pattern in the city, by using retrospective data on malaria burden by species, malaria related inpatient department (IPD) and outpatient department (OPD) consultations from 2013/14 to 2017/18.ResultsOPD retrospective data analysis indicated that adolescents and adults (≥ 15 years of age) were most affected by P. vivax 43.5% (2986/6862) and P. falciparum 31.7% (2179/6862). Plasmodium vivax was found to be a predominant species in causing malaria burden in the city exhibiting less seasonal occurrence, and the relative burden of P. vivax is gradually increasing from year to year over P. falciparum.ConclusionMalaria is endemic to the city showing a public health problem. The productive group of the community, adolescents and adults, were most affected exacerbating poverty. Plasmodium vivax was found to be the highest malaria burden in the city and the observed epidemiological shift from P. falciparum to P. vivax calls for additional tailored intervention strategies to reduce the associated burden.

Suitable identification of underground dam locations, using decision-making methods in a semi-arid region of Iranian Semnan Plain

The problem of water shortage has always been one of the most principle issues in the world. Due to the seasonality of the surface water drainages and subsurface structures in semi-arid and arid regions, it is necessary to use structures like underground dams. Underground dams are structures that are constructed on the waterways of the groundwater and cause the water to rise and store in its reservoir. Due to the costly and timely location of underground dams, the use of GIS techniques along with decision-making methods is considered as one of the tools used in these studies. The study area is located on the northwest of Semnan province in Iran. The purpose of this study was to determine the proper location of underground dam with using decision-making methods. In this research, at the first step, the necessity of selecting a subsurface water drainage structure that stores and controls flow of water in semi-arid and arid areas are reviewed. At second step, a number of criteria influence upon the decision-making process during the identification of the most suitable site is concerned. Step three was applying AHP technique to prioritize eight different locations, concerning diverse aspects including economic, environmental, technical, and social. At the fourth step, the techniques of TOPSIS and EDAS are applied resulting in prioritizations that appear to have approximately ranked the same. Finally, four axes as the best ones were able to be offered as agreed upon by all groups regarding the sites of underground dam construction.

Impact of urbanization on the river Yamuna basin

ABSTRACT This paper analyses the pattern of urbanization and its impact on the quality and quantity of flow in the Yamuna river basin, India. The Yamuna river basin is a part of Great Ganga–Brahmaputra basin in India. During the last two decades, the basin has undergone urbanization at an unprecedented rate. The number of cities and towns in the basin has significantly increased over the last few decades, leading to an increase in water demand and reduction in water holding capacity in the basin. Urbanization has resulted in adverse impacts on the surface water drainage system that often gets clogged up due to siltation. Although the flow during the monsoon season has increased in the river Yamuna, the water availability during the dry season is still not adequate to meet various competing demands. An adverse impact of urbanization has been on the quality of river flow, which has deteriorated largely due to the disposal of untreated industrial and domestic sewage in the river. Due to urbanization, the flooding events in the basin, both in terms of magnitude and frequency, have exhibited an increasing pattern. Consequently, the vulnerability of thickly populated areas along the river has increased. Several implementable measures for sustainable development and flood risk management of the river Yamuna basin have been suggested in this paper. The results of the study presented herein could be effectively utilized by basin managers and planners to mitigate the adverse impacts of urbanization in river Yamuna basin.

Multi-criteria evaluation of suitable sites for termite mounds construction in a tropical lowland

Termite mounds influence ecosystem heterogeneity and contribute to the stabilization of the system under global change. A number of environmental factors influence the distribution, height, diameter and designs of termite mounds but these factors are not only poorly understood, they cannot be extrapolated for everywhere. In this study, we employed a ground based survey and Geographical Information System (GIS) technique to map 156 km2 study area in Keffi, Nigeria. The aims were to (1) estimate the density and area covered by termite mounds, (2) sample and identify species types and how they are distributed, and (3) use five environmental factors (elevation, geology, surface water drainage, land use/land cover and static water level) to model suitable sites for mounds construction. A total of 361 mounds were mapped representing a density of about 0.8 mounds ha−1 and covering only about 0.31% of the studied area. Next, the effect of the five chosen environmental factors on the geographic distribution, life status, height and diameter of mounds and species diversity were analysed and their relationships plotted in pairwise comparison matrices using the Saaty's Analytical Hierarchy Process. Normalized rates for classes in each factor and corresponding weights were computed and aggregated using the Weighted Linear Combination method. The result depicted that moderate to low elevation (270–330 m amsl), rock cover types that are more susceptible to weathering (schist), cultivated areas and shallow water table zones are most favourable for termites to build mounds. The result obtained in this study shows a promising correlation between the environmental factors and termite mounds distribution. The proposed model can easily be replicated in a different but similar multi-land use and rock cover types.

Vulnerability analysis of building structures to floods

PurposeThere is evidence of increasing urban floods being aftermath of climate change. The purpose of this paper is to present findings-related analysis of vulnerability of building structures in informal settlements to floods and associated coping strategies.Design/methodology/approachThe study adopted a case study strategy, supported by field surveys and laboratory experiments. The informal settlement taken as case study is Sunna sub-ward. Field surveys involved interviews, questionnaires and observations and tests were conducted to determine the strength of walls, blocks and mortar.FindingsThe findings reveal that vulnerability of building structures to floods are due to poor quality of materials used in construction of houses which are influenced by income levels, location (lower areas of Sunna sub-ward) and inadequate storm water drainage system. Moreover, socio-economic vulnerabilities do exist in the settlements and are related to lack of peace of mind, outbreak of disease and expenses related to repairing of flood affected houses. Coping strategies used in the sub-ward for built structures are building barrier walls at the front door of the house and use multiple strategies which are supported by reactive and recovery strategies.Research limitations/implicationsThe findings of this study were mostly affected by limited knowledge of respondents on construction materials and processes.Practical implicationsFindings of the paper provide an insight on the effects of climate change on building structures in informal settlements and coping strategies in place to protect buildings. The outputs can be used for any other informal settlement in Dar es Salaam the only limitation is the terrain.Originality/valueThe paper recommends use of quality building materials and technicians/artisans, improvement of surface water drainage and training of residents on the effects of climate change and variability. In addition, promising coping strategies should be adopted while those under-performing should be discouraged as they increase the cost burden among the urban poor.

The Effects of Urban Spatial Development on Coastal Ecosystems: The Case of Mersin, Turkey

In the process of urbanization, protection of ecosystems and ensuring the continuity of the services they provide are very important in terms of the functionality of life support systems. Otherwise, degradation in ecosystems can have negative consequences for different dimensions, such as biodiversity decline, over-consumption of resources and climate change. In this context, as a result of urbanization, the loss of surface water drainage areas, the interruption of the continuity of green corridors and the increase in the size of impermeable surfaces cause problems in terms of sustainable development. Therefore, the attempts to ensure urban spatial development in harmony with natural areas in coastal areas are one of the most important issues of the planning agenda. The aim of the study is to reveal the relationship between the urban development pattern and the natural areas in the context of sustainable urban development, in the case of Mersin a coastal city in southern of Turkey. For this purpose, an interdisciplinary approach by using geographic information systems and remote sensing has been applied to understand the urban spatial patterns of Mersin. A multi-temporal change by using a series of satellite images for the three periods of 1987-2000-2015 have been analyzed. Threshold values was employed to detect built-up land and non-built-up land on the images. The results revealed that Mersin has spatially grown more than 6 times since 1980. The spatial growth is observed to increase by 80 % between 1987 and 2000 and by 60 % between 2000 and 2015. Under these circumstances, the development in Mersin has resulted in critical problems about decreasing of natural area in size, disconnecting of green network and degradation of coastal ecosystem. The results of the paper highlight the importance of determining the measurable variables for analyzing problems of urban forms for the future development strategies of cities.

Comparing cost‐effectiveness of surface water flood management interventions in a UK catchment

Despite significant consequences caused by recent events, surface water flooding has historically been of lower priority relative to fluvial and coastal risks in UK flood management. Legislation and research proposes a variety of innovative interventions to address this; however, widespread application of these remains a challenge due to a number of institutional, economic, and technical barriers. This research applies a framework capable of fast and high‐resolution assessment of intervention cost‐effectiveness as an opportunity to improve available evidence and encourage uptake of interventions through analysing permutations of type, scale, and distribution in urban catchments. Fast assessment of many scenarios is achieved using a cellular automata flood model and a simplified representation of interventions. Conventional and green strategies are examined across a range of design standard and high‐magnitude rainfall events in an urban catchment. Results indicate high‐volume rainwater capture interventions demonstrate a significant reduction in estimated annual damage costs, and localised surface water drainage interventions exhibit high cost‐effectiveness for damage reduction. Analysis of performance across a wide range of return periods enhances available evidence for option comparison decision support and provides a basis for future resilience assessment of interventions.

Infiltration capacity of cracked pavements

Understanding the hydrological behaviour of urban surfaces is imperative in the design of surface water drainage systems and flood mitigation strategies, as well as for the modelling of groundwater recharge and pollution. This study has examined the hydrological behaviour of cracked impervious surfaces through field infiltration testing and image analysis of the cracks themselves. Infiltration tests were undertaken on a section of concrete slab pavers paving. The results showed that cracks in impervious surfaces allow significant volumes of water to infiltrate through them, with infiltration rates comparable to those found in sands and gravels. Using a regression model, infiltration rates were related directly to crack characteristics obtained from image processing software, thereby enabling the first published quantitative link between percentage cracked area and infiltration capacity. The implications of accounting for this infiltration for surface water management systems are estimated to be in the order of £20 million annually for the construction industry in England.