Search results for " basin"
showing 10 items of 838 documents
Decadal oscillations of the aquatic chemistry of river waters in Latvia
2018
Abstract. Water quality changes of surface waters can be used to assess human impact intensity, but of importance is to consider also impacts of climate change/variability and naturally occurring changes of environmental quality. In Latvia, during the recent decades a major reduction of anthropogenic pressure has happened due to restructuring of economy and industrial production, resulting in major decrease of loading of many groups of pollutants. However, trends and driving factors for other groups of substances have not been much studied. Long term (1980–2012) results of hydrochemical monitoring, performed in rivers of Latvia, are analysed during this study in connection with long-term se…
WATER MANAGEMENT PROBLEMS AT THE BUKÓWKA DRINKING WATER RESERVOIR’S CROSS-BORDER BASIN AREA IN TERMS OF ITS ESTABLISHED FUNCTIONS
2015
The paper covers the analysis of water management problems in the cross-border reservoir basin of Bukówka, located at the Bóbr river, at 271+540 km of its course, below the Czech-Polish border, in Dolnośląskie Voivodeship. The problems of water management in the context of the reservoir’s functions have been analyzed; these are: flood control, the provision of water during low water level periods for the Water Treatment Plant in Marciszów, the provision of drinking water for the city of Wałbrzych as well as the provision of proper flow in the Bóbr river bed downstream from the reservoir. Due to its localization right below the border with the Czech Republic, the reservoir is exposed to a nu…
Parametric uncertainty or hydrological changes?
2014
Abstract. The model calibration is the way of hydrologists for searching also a physical interpretation of complex interactions acting within a basin. Actually, it can be frequently noticed how model calibration performed on a given time-window may converge to a point in the parameter space that could be distant from another obtainable calibration of the model in the same basin but considering a different time window. Is that again parametric uncertainty or does the trajectory in the parametric space relate about to a slow hydrological basin change? This paper depicts a possible path for detecting changes' signatures in a streamflow time series. In particular, the paper seeks to draw a way …
Assessment of the changes of COD and color in rivers of Latvia during the last twenty years
1998
Analysis of long-term records of the concentrations of water color and chemical oxygen demand for nine river sites in Latvia is reported. The period of observations lasted for the last 20 years. Characteristic features of data include non-normal distributions, serial correlation, seasonality and presence of mostly significant downward trends. In Latvia, the main water quality changes could be explained by the changes of anthropogenic impact and the type of catchment management over the last 20 years.
Potential of historical meteorological and hydrological data for the reconstruction of historical flood events – the example of the 1882 flood in sou…
2009
Abstract. This paper presents a hydrometeorological reconstruction of the flood triggering meteorological situation and the simulation of discharges of the flood event of December 1882 in the Neckar catchment in Baden-Württemberg (southwest Germany). The course of the 1882 flood event in the Neckar catchment in southwest Germany and the weather conditions which led to this flood were reconstructed by evaluating the information from various historical sources. From these historical data, daily input data sets were derived for run-off modeling. For the determination of the precipitation pattern at the end of December 1882, the sparse historical data were modified by using a similar modern day…
Climate and extreme rainfall events in the Mono river basin (West Africa): investigating future changes with Regional Climate Models.
2020
This study characterizes the future changes in extreme rainfall and air temperature in the Mono river basin where the main economic activity is weather dependent and local populations are highly vulnerable to natural hazards, including flood inundations. Daily precipitation and temperature from observational datasets and Regional Climate Models (RCMs) output from REMO, RegCM, HadRM3, and RCA were used to analyze climatic variations in space and time, and fit a GEV model to investigate the extreme rainfalls and their return periods. The results indicate that the realism of the simulated climate in this domain is mainly controlled by the choice of the RCMs. These RCMs projected a 1 to 1.5 °
Generation of Natural Runoff Monthly Series at Ungauged Sites Using a Regional Regressive Model
2016
Many hydrologic applications require reliable estimates of runoff in river basins to face the widespread lack of data, both in time and in space. A regional method for the reconstruction of monthly runoff series is here developed and applied to Sicily (Italy). A simple modeling structure is adopted, consisting of a regression-based rainfall–runoff model with four model parameters, calibrated through a two-step procedure. Monthly runoff estimates are based on precipitation, temperature, and exploiting the autocorrelation with runoff at the previous month. Model parameters are assessed by specific regional equations as a function of easily measurable physical and climate basin descriptors. Th…
The Use of Non-Conventional Water Resources as a Means of Adaptation to Drought and Climate Change in Semi-Arid Regions: South-Eastern Spain
2019
Drought is a climatic risk with notable repercussions on water supply systems. The aim of this study is to analyze the principal measures for management and planning implemented during recent decades in south-eastern Spain (Segura River Basin) to respond to drought situations, focusing on the role played by non-conventional water resources (desalination and treated water). The results demonstrate that the study area (despite being one of the driest places of Spain) is less vulnerable to drought than regions with an Atlantic climate and greater availability of water. This has been possible thanks to the integration of non-conventional water resources as a means of adaptation to confront this…
Spectrofluorimetric study of dissolved organic matter in River Salaca (Latvia) basin waters
2012
Dissolved organic matter (DOM) in surface waters influences mineral weathering, nutrient cycling, aggregation of particulate matter and photochemical reactions in waters and aquatic communities. In this study, the effectiveness of UV and fluorescence measurements in distinguishing the origin of DOM and processes within the river basin were analyzed using the River Salaca basin as an example. The basin of River Salaca is characterized by low anthropogenic pressure, however, the water color during the last few decades has increased (an effect known as brownification). As tools to study the composition of dissolved organic substances in waters of the River Salaca and its tributaries the use of…
Sequence of deformation in the sicilidi units (northern sicilian chain)
2004
The foredeep deposits of Northern Sicily, indicated as Sicilidi units, have undergone different deformations' since Oligocene time. The resulting tectonic Structures, analysed in several outcrops in the Eastern Madonie Mts, are 1 cm-to- 100 m in scale and are similar to the larger structures forming the Sicily belt, allowing for scale extrapolation. Also the overprinting relationships of the minor structures recorded in the so-called Tufiti di Tusa reflect the sequence of fault activation which determined the present-day geometry of the tectonic units, suggesting that the tectonic evolution of the foreland basin developed during the stacking of the Maghrebide fold-and-thrust belt. The overp…