Search results for "surface runoff"
showing 10 items of 241 documents
Rainwater Reuse in Urban Areas: A Mathematical Model and a Long-Term Modelling Approach
2018
Natural water resources are becoming increasingly limited due to global-scale climate change and water availability issues have become so severe that they must be addressed. Given these issues, reuse of wastewater and rainwater provides a promising way to cope with water shortages. This paper describes an investigation into the efficiency of rainwater usage systems. A conceptual model was built to assess the behaviour of rainwater tanks and their effectiveness in coping with water shortages. The study is based on a long-term simulation (12 years) of different rainwater reuse tank schemes. The associated reductions in residential freshwater demand (water reuse efficiency) and wet-weather run…
Long-Range Ecogeomorphic Processes
2013
Processes operating at larger spatial scales interact with those operating at smaller scales (discussed in the previous chapter) to produce spatial patterns in drylands. Hydrological processes operating at the catchment scale, the effects of grazing, fire, water and wind erosion are considered separately and in relation to their interactions with propagules and plants. The chapter concludes with a consideration of the extent to which feedbacks are central to pattern formation.
Urban Storm-Water Quality Management: Centralized versus Source Control
2010
The continuous growth of urban areas and the increasing public awareness of the environmental impacts of storm water have raised interest on the quality of the receiving water bodies. In the past two decades, many efforts have been directed at improving urban drainage systems by introducing mitigation measures to limit the negative environmental impacts of storm water. These mitigation measures are generally called best management practices (BMPs), sustainable urban drainage systems, or low impact developments, and they include practices such as infiltration and storage tanks that reduce the peak flow and retain some of the polluting materials. Choosing the best mitigation measure is still …
A Check of Water Drop Impact Effects on Surface Soil Saturated Hydraulic Conductivity
2020
The post-tillage dynamics of the surface soil saturated hydraulic conductivity, Ks, was studied at the Masse experimental station (central Italy, silty-clay-loam soil). A sequence of experiments was performed by rainfall simulation on two replicated micro-plots (width 1 m, length 0.92 m, slope 16%) established on bare soil. Each high-intensity rainfall simulation was preceded by a low-intensity wetting phase. The soil water content, w, was measured before wetting and both before and after simulation. Runoff was measured at 5 min intervals. The infiltration rate was calculated as the difference between rainfall intensity and runoff rate. Finally, Ks was assumed to be equal to the infiltratio…
Pinus halepensis M. versus Quercus ilex subsp. Rotundifolia L. runoff and soil erosion at pedon scale under natural rainfall in Eastern Spain three d…
2017
Abstract Afforestation aims to recover the vegetation cover, and restore natural ecosystems. The plant species selected for restoration will determine species richness and the fate of the ecosystem. Research focussing on the impact of vegetation recovery on soil quality are abundant, especially on fire affected land and where rehabilitation, afforestation and restoration projects were carried out. However, little is known about how different plants species affect soil erosion and water losses, which are key factors that will impact the fate of the afforested land. Aleppo pine (Pinus halepensis M.) is the species commonly used for afforestation in the Mediterranean and is very successful whe…
The green roofs for reduction in the load on rainwater drainage in highly urbanised areas
2021
AbstractRapid weather phenomena, particularly sudden and intense rainfall, have become a problem in urban areas in recent years. During heavy rainfall, urban rainwater drainage systems are unable to discharge huge amounts of runoff into collecting reservoirs, which usually results in local flooding. This paper presents attempts to forecast a reduction in the load on the rainwater drainage system through the implementation of green roofs in a case study covering two selected districts of Opole (Poland)—the Old Town and the City Centre. Model tests of extensive and intensive roofs were carried out, in order to determine the reduction of rainwater runoff from the roof surface for the site unde…
Rainfall and water yield in Macizo del Caroig, Eastern Iberian Peninsula. Event runoff at plot scale during a rare flash flood at the Barranco de Ben…
2021
[EN] Floods are a consequence of extreme rainfall events. Although surface runoff generation is the origin of discharge, flood research usually focuses on lowlands where the impact is higher. Runoff and sediment delivery at slope and pedon scale receiving much less attention in the effort to understand flood behaviour in time and space. This is especially relevant in areas where, due to climatic and hydrogeological conditions, streams are ephemeral, so-called dry rivers (¿wadis¿, "ramblas" or ¿barrancos¿) that are widespread throughout the Mediterranean. This paper researches the relationship between water delivery at pedon and slope scale with dry river floods in Macizo del Caroig, Eastern…
Assessing hydrological connectivity inside a soil by fast-field-cycling nuclear magnetic resonance relaxometry and its link to sediment delivery proc…
2017
Connectivity is a general concept used to represent the processes involving a transfer of matter among the elements of an environmental system. The expression “hydrological connectivity inside the soil” has been used here to indicate how spatial patterns inside the soil (i.e., the structural connectivity) interact with physical and chemical processes (i.e., the functional connectivity) in order to determine the subsurface flow (i.e., the water transfer), thereby explaining how sediment transport due to surface runoff (i.e., the soil particle transfer) can be affected. This paper explores the hydrological connectivity inside the soil (HCS) and its link to sediment delivery processes at the p…
Measuring hydrological connectivity inside soils with different texture by fast field cycling nuclear magnetic resonance relaxometry
2022
Abstract The locution “hydrological connectivity inside the soil” is generally used to disclose how the spatial patterns inside the soil affect the physical–chemical processes at a molecular level to influence water transfer into the soil, the surface runoff and related sediment transport. Fast Field Cycling (FFC) Nuclear Magnetic Resonance (NMR) relaxometry has been used to measure both structural and functional connectivity by two indexes indicated as structural (SCI) and functional (FCI) connectivity index. Here, FFC-NMR relaxometry has been applied to analyze three samples: two non-degraded soils, having different grain-size distribution, and a degraded soil sampled in a badland area. P…
Urban Stormwater Management, A Tool for Adapting to Climate Change: From Risk to Resource
2020
The effects of climate change on rainfall in the Mediterranean region are manifested in an overall decreasing trend, and greater irregularity in annual volumes and the city of Alicante is no exception. In addition, there has also been a spread of the urbanised area, which has led to an increase in the flood risk in urban areas (due to a greater runoff and the occupation of flood hazard areas) and drought events due to an increase in the water demand. In light of these new scenarios, the Mediterranean cities should design adaptation systems based on rainwater harvesting within the framework of a circular economy. This study analyses the integration of rainwater in flood and water demand mana…