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Temporal variability in spatial correlation of daily rainfall

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

Spatial and temporal characteristics of high-intensive rainfall in northern Tunisia

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

Calculation of mass transport of pollutants via storm water discharge

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

Numerical simulation of saltwater intrusion into Laccadive Island aquifers due to climate change

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

An analysis of the rainfall time structure by box counting-some practical implications

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 wheat and soil

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

Lateral bromide distribution in a vertic clay soil

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

Some Eulerian and Lagrangian statistical properties of rainfall at small space-time scales

Management of urban hydrological systems requires a knowledge of short-term and small-scale rainfall properties. Small catchment areas, dense building structures, a high degree of impermeable areas, and resulting rapid runoff, mean that the properties of individual rain cells are important considerations. Accordingly, this paper characterizes mainly spatial rainfall properties on a scale suitable

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The infiltration equations according to Horton and Philip are applied to 52 double-ring infiltrometer tests performed in a small semiarid catchment in northern Tunisia. Spatial variability in infiltration properties is analysed as regards the coefficients of the two equations. Different geomorphological zones display different infiltration characteristics even if there is large variability within

Transport and sedimentation of pollutants in a river reach : A chemical mass balance approach

The River Höje in the south of Sweden is a typical receiving water for urban and rural runoff. Mass balance calculations over a 17‐month period indicate that pollutants are retained in the sediments of the investigated 5‐km‐long reach of the stream (90 tons of biochemical oxygen demand (BOD7), 850 tons of chloride, 2.1 tons of copper, 3.2 tons of zinc, and 1.0 ton of lead). Other pollutants such a

Rainfall estimation in the Chikugo River Basin by Atmospheric downscaling using artificial networks

For the proper water resources management of the Chikugo River basin, the prediction of both drought and heavy rainfall needs to be carried out by the conventional and engineering method which can be useful to for the practitioners who work on the water resources management and flood control. A relatively simple and efficient way to estimate local and regional rainfall, as well as other hydrometeo

Parameterization of rain cell properties using an advection-diffusion model and rain gage data

To reduce flooding risks and improve urban drainage management, there is a need to increase the forecasting accuracy for rainfall models on small typical urban time and space scales. Increased rainfall forecasting accuracy will in turn improve runoff prediction and thus, prevent flooding hazards, decrease pollution discharge through combined sewers, increase waste water treatment efficiency, etc.

Heavy Metal Transport in Different Drip-Irrigated Soil Types with Potato Crop

Heavy metal (HM)-polluted soil is a serious concern, especially as brackish water is widely used for irrigation purposes in water-scarce countries. In this study, the HYDRUS-2D model was used to simulate HM (copper (Cu), lead (Pb), and zinc (Zn)) transport through agricultural land cultivated with potato crops under surface drip irrigation to explore the potential groundwater contamination risk. T

Temporal rainfall disaggregration based on scaling properties

The present study concerns disaggregation of daily rainfall time series into higher resolution. For this purpose, the scaling-based cascade model proposed by Olsson (1998) is employed. This model operates by dividing each rainy time period into halves of equal length and distributing the rainfall volume between the halves. For this distribution three possible cases are defined, and the occurrence

Predicting Soil Saturated Water Conductivity Using Pedo-Transfer Functions for Rocky Mountain Forests in Northern China

Soil physicochemical properties and macropore spatial structure affect saturated hydraulic conductivity (Ks). However, due to regional differences and long measurement time, Ks is tedious to quantify. Therefore, it is of great importance to find simplified but robust methods to predict Ks. One possibility is to use pedo-transfer functions (PTFs). Along this line, stratified sampling was carried ou