Providing safe drinking water to people in developing countries is an urgent worldwide water problem and a main issue in the UN Sustainable Development Goals. One of the most efficient and cheapest methods to attain these goals is to promote the use of slow sand filters. This review shows that slow sand filters can efficiently provide safe drinking water to people living in rural communities not s

The transformation of rainfall into runoff is one of the most important processes in hydrology. In the past few decades, a wide variety of automated or computer-based approaches have been applied to model this process. However, many such approaches have an important limitation in that they treat the rainfall-runoff process as a realization of only a few parameters of linear relationships rather th

Time-domain reflectometry (TDR) is an electromagnetic technique for measurements of water and solute transport in soils. The relationship between the TDR-measured dielectric constant (Ka) and bulk soil electrical conductivity ([sgrave]a) to water content (θW) and solute concentration is difficult to describe physically due to the complex dielectric response of wet soil. This has led to the develop

The present study aimed at investigating whether a nonlinear and scaling approach is suitable for statistically characterizing the spatial variability of soil geochemical element contents at field conditions. Spatial distributions of 20 soil geochemical elements' contents in an agricultural field soil were investigated. Two indicators of nonlinear scaling were employed, empirical probability distr

A total of 200 heavy rainfall events with duration from 1 to 10 days were studied regarding maximum point depth, duration, areal extent, storm centre distribution, and seasonal distribution. The data base includes daily rainfall recordings from 78 stations in the Hongru River basin, an upper tributary to the Huai River, from 1955 to 1987. The 12 380 km2 large basin is situated on the outskirts of

In developing countries, the use of mathematical models in hydrological forecasting is increasing, making for optimal planning and management of water resources systems. Such application, however, faces different problems. One of these problems is that computers may not be available. Even if they are available, computer time is expensive. Hence, there is a need for simple models which can be run o

Spring water, however, is often formed in complex geological formations and therefore it is difficult to determine the catchment area contributing to the flow. The Sayanokami spring, located in western part of Fukuoka City, Japan, is such a spring and an important water resource for the local agriculture. In order to better understand the hydrological properties of infiltration and groundwater pro

Spatial variation patterns of soil water content are investigated along a bare soil transect covering a crest-to-crest spacing (about 60 m) in a shifting sand dune area. Soil water content analyses from gravimetrical soil sampling and neutron probe observations are shown to give different information regarding variability patterns. Gravimetrical sampling displays a large effect of a small rainfall

The spatial properties of the correlation structure based on daily rainfall data from 67 stations throughout Tunisia over a 5‐year period are examined. The correlation structure is generally markedly anisotropic as influenced by topography and the coast. These two factors seem to influence the correlation pattern differently during different months. The mean areas within the 0.7 correlation isolin

Composite correlation fields based on a 5‐year record of daily rainfall at 67 stations throughout Tunisia were used to investigate spatial and temporal properties of rainfall fields. The composite correlation fields had in general banded or elliptical patterns and with the elongations generally along the coastline or the topographical ridges. The banded patterns occurred usually during the rainy s

When dealing with urban design, it is essential to have knowledge of the magnitude of the spatial variability of short high-intensive rainstorms. Most of the studies of high-intensive rainfall, conducted during recent years, concern regions with a humid climate. Still, the largest temporal and spatial variations in rainfall are to be found in arid and semi-arid regions. This paper sums up findings

The National Swedish Environmental Protection Board recommends a standard value method for calculation of mass transport of pollutants via storm water sewer systems. In this paper mass transport calculations based on this method are compared with actual measurements. Measurements during one and a half years in the city of Lund show high amounts of leakage and drainage into the storm water sewer sy

Ratios for urban discharge and recipient flow during different time intervals are presented and discussed. The quality of the urban discharge is illustrated through pollutographs.-Authors

Saltwater intrusion is a serious environmental problem in coastal subsurface water systems around the world. In the development of subsurface water protection and rehabilitation strategies in the coastal areas, mathematical models play an important role. This paper discusses the role of subsurface water contamination models in planning, management and regulation, with a focus on generic and site s

The scale-invariant behavior of the rainfall time structure was investigated by applying the box counting method to rainfall time series. Two years of minute observations, 90 years of daily observations and 170 years of monthly observations were analyzed and the results were interpreted and related to physical properties of the rainfall process. This paper discusses the question of whether an hypo

Field variability of element concentrations in crops is important to consider for nutrient application as well as for evaluation of environmental hazards. The paper gives an analysis of spatially sampled wheat plant tissue in the field to determine spatial properties of 20 elements for a partly sludge-applied agricultural soil in northern Tunisia. A comparison is made with the spatial variability

In order to control the transport of toxic elements, dissolved salts, and nutrients in agricultural areas, information on the spatial variability of field-scale transport properties is needed. To evaluate this for an unsaturated layered clayey soil, tracer tests were conducted at the Cherfech experimental field research station in Tunisia. Bromide-tagged water was infiltrated under ponding conditi