bluuebunny/crossref_metadata_2025 huggingface dataset:
Modelling impacts of climate and deposition changes on nitrogen fluxes in northern catchments of Norway and Finland
Authors: Kaste Ø. , Rankinen K. , Lepistö A.
Published: April 2010

Abstract. The Integrated Nitrogen model for Catchments (INCA) was applied to three upland catchments in Norway and Finland to assess the possible impacts of climate change and nitrogen (N) deposition on concentrations and fluxes of N in streamwater in cold regions of Europe. The study sites cover gradients in climate and N deposition from the southern boreal Øygard Brook (2.6 km2) in SW Norway, via the southern/middle boreal Simojoki River (3610 km2) in northern Finland to the sub-arctic Dalelva Brook (3.2 km2) in northern Norway. The INCA scenario simulations included future N deposition scenarios (current legislation and maximum feasible reduction) and climate scenarios for 2050 (ECHAM4/OPYC3; HadCM3) treated separately and in combination. As a result of climate change, the INCA model predicted markedly reduced duration and amounts of snow cover in all catchments. The occurrence of winter rainfall and melting periods was predicted to become more frequent so that more frequent floods in winter will to a large extent replace the regular snowmelt flood in spring. At the northernmost catchment, Dalelva, the predicted temperature increase might result in a doubling of the net mineralisation rate, thereby greatly increasing the amount of available inorganic N. At all catchments, the increased N supply was predicted to be largely balanced by a corresponding increase in N retention, and relatively small increases in NO3- leaching rates were predicted. This dynamic relationship is, however, strongly dependent on the temperature responses of the key N transformation processes modelled. A future reduction in N emissions and deposition, as agreed under current legislation, would have pronounced effects on concentrations of NO3- in streamwater at the southernmost catchment, Øygard, even following a climate change around 2050. At the more remote Dalelva and Simojoki catchments, the N emission reductions will be small compared to the internal N recycling processes, and climate change will to a large extent offset the effects of reduced N deposition. Keywords: catchments, surface water, scenarios, climate, hydrology, nitrogen deposition, nitrate leaching
Towards a nutrient export risk matrix approach to managing agricultural pollution at source
Authors: Hewett C. J. M. , Quinn P. F. , Whitehead P. G. , Heathwaite A. L. , Flynn N. J.
Published: April 2010

Abstract. A generic Nutrient Export Risk Matrix (NERM) approach is presented. This provides advice to farmers and policy makers on good practice for reducing nutrient loss and, hopefully, persuades them to implement such measures. Combined with a range of nutrient transport modelling tools and field experiments, NERMs can play an important role in reducing nutrient export from agricultural land. The Phosphorus Export Risk Matrix (PERM) is presented as an example NERM. The PERM integrates hydrological understanding of runoff with a number of agronomic and policy factors into a clear problem-solving framework. This allows farmers and policy makers to visualise strategies for reducing phosphorus loss through proactive land management. The risk of pollution is assessed by a series of informed questions relating to farming intensity and practice. This information is combined with the concept of runoff management to point towards simple, practical remedial strategies which do not compromise farmers’ ability to obtain sound economic returns from their crop and livestock. Keywords: nutrients, phosphorus, export, risk, decision support, matrix
Modelling monthly runoff generation processes following land use changes: groundwater–surface runoff interactions
Authors: Bari M. , Smettem K. R. J.
Published: April 2010

Abstract. A conceptual water balance model is presented to represent changes in monthly water balance following land use changes. Monthly rainfall–runoff, groundwater and soil moisture data from four experimental catchments in Western Australia have been analysed. Two of these catchments, "Ernies" (control, fully forested) and "Lemon" (54% cleared) are in a zone of mean annual rainfall of 725 mm, while "Salmon" (control, fully forested) and "Wights" (100% cleared) are in a zone with mean annual rainfall of 1125 mm. At the Salmon forested control catchment, streamflow comprises surface runoff, base flow and interflow components. In the Wights catchment, cleared of native forest for pasture development, all three components increased, groundwater levels rose significantly and stream zone saturated area increased from 1% to 15% of the catchment area. It took seven years after clearing for the rainfall–runoff generation process to stabilise in 1984. At the Ernies forested control catchment, the permanent groundwater system is 20 m below the stream bed and so does not contribute to streamflow. Following partial clearing of forest in the Lemon catchment, groundwater rose steadily and reached the stream bed by 1987. The streamflow increased in two phases: (i) immediately after clearing due to reduced evapotranspiration, and (ii) through an increase in the groundwater-induced stream zone saturated area after 1987. After analysing all the data available, a conceptual monthly model was created, comprising four inter-connecting stores: (i) an upper zone unsaturated store, (ii) a transient stream zone store, (ii) a lower zone unsaturated store and (iv) a saturated groundwater store. Data such as rooting depth, Leaf Area Index, soil porosity, profile thickness, depth to groundwater, stream length and surface slope were incorporated into the model as a priori defined attributes. The catchment average values for different stores were determined through matching observed and predicted monthly hydrographs. The observed and predicted monthly runoff for all catchments matched well with coefficients of determination (R2) ranging from 0.68 to 0.87. Predictions were relatively poor for: (i) the Ernies catchment (lowest rainfall, forested), and (ii) months with very high flows. Overall, the predicted mean annual streamflow was within ±8% of the observed values. Keywords: monthly streamflow, land use change, conceptual model, data-based approach, groundwater
Strontium isotope geochemistry of alluvial groundwater: a tracer for groundwater resources characterisation
Authors: Négrel P. , Petelet-Giraud E. , Widory D.
Published: April 2010

Abstract. This study presents strontium isotope and major ion data of shallow groundwater and river water from the Ile du Chambon catchment, located on the Allier river in the Massif Central (France). There are large variations in the major-element contents in the surface- and groundwater. Plotting of Na vs. Cl contents and Ca, Mg, NO3, K, SO4, HCO3, Sr concentrations reflect water–rock interaction (carbonate dissolution for Ca, Mg, HCO3 and Sr because the bedrock contains marly limestones), agricultural input (farming and fertilising) and sewage effluents (for NO3, K, SO4), although some water samples are unpolluted. Sr contents and isotope ratios (87Sr/86Sr vary from 0.70892 to 0.71180 along the hydrological cycle) in the groundwater agree with previous work on groundwater in alluvial aquifers in the Loire catchment. The data plot along three directions in a 87Sr/86Sr v. 1/Sr diagram as a result of mixing, involving at least three geochemical signatures–Allier river water, and two distinct signatures that might be related to different water-rock interactions in the catchment. Mixing proportions are calculated and discussed. The alluvial aquifer of the Ile du Chambon catchment is considered, within the Sr isotope systematic, in a larger scheme that includes several alluvial aquifers of the Loire Allier catchment. Keywords: : Loire river, major and trace elements, Sr isotopic ratio, alluvial aquifer, hydrology
Comparison of mercury in atmospheric deposition and in Illinois and USA soils
Authors: Krug E.C. , Winstanley D.
Published: April 2010

Abstract. It has been reported that most mercury (Hg) in USA soils is from atmospheric Hg deposition, mostly from anthropogenic sources. This paper compares the rates of atmospheric Hg deposition to amounts of Hg in Illinois and USA soils. The amounts of Hg in these soils are too great to be attributed mainly to anthropogenic atmospheric Hg deposition. Keywords: mercury, atmospheric deposition, soil, geology, Illinois, USA
Limited-area short-range ensemble predictions targeted for heavy rain in Europe
Authors: Sattler K. , Feddersen H.
Published: April 2010

Abstract. Inherent uncertainties in short-range quantitative precipitation forecasts (QPF) from the high-resolution, limited-area numerical weather prediction model DMI-HIRLAM (LAM) are addressed using two different approaches to creating a small ensemble of LAM simulations, with focus on prediction of extreme rainfall events over European river basins. The first ensemble type is designed to represent uncertainty in the atmospheric state of the initial condition and at the lateral LAM boundaries. The global ensemble prediction system (EPS) from ECMWF serves as host model to the LAM and provides the state perturbations, from which a small set of significant members is selected. The significance is estimated on the basis of accumulated precipitation over a target area of interest, which contains the river basin(s) under consideration. The selected members provide the initial and boundary data for the ensemble integration in the LAM. A second ensemble approach tries to address a portion of the model-inherent uncertainty responsible for errors in the forecasted precipitation field by utilising different parameterisation schemes for condensation and convection in the LAM. Three periods around historical heavy rain events that caused or contributed to disastrous river flooding in Europe are used to study the performance of the LAM ensemble designs. The three cases exhibit different dynamic and synoptic characteristics and provide an indication of the ensemble qualities in different weather situations. Precipitation analyses from the Deutsche Wetterdienst (DWD) are used as the verifying reference and a comparison of daily rainfall amounts is referred to the respective river basins of the historical cases.
Precipitation forecasts and their uncertainty as input into hydrological models
Authors: Kobold M. , Sušelj K.
Published: April 2010

Abstract. Torrential streams and fast runoff are characteristic of most Slovenian rivers and extensive damage is caused almost every year by rainstorms affecting different regions of Slovenia. Rainfall-runoff models which are tools for runoff calculation can be used for flood forecasting. In Slovenia, the lag time between rainfall and runoff is only a few hours and on-line data are used only for now-casting. Predicted precipitation is necessary in flood forecasting some days ahead. The ECMWF (European Centre for Medium-Range Weather Forecasts) model gives general forecasts several days ahead while more detailed precipitation data with the ALADIN/SI model are available for two days ahead. Combining the weather forecasts with the information on catchment conditions and a hydrological forecasting model can give advance warning of potential flooding notwithstanding a certain degree of uncertainty in using precipitation forecasts based on meteorological models. Analysis of the sensitivity of the hydrological model to the rainfall error has shown that the deviation in runoff is much larger than the rainfall deviation. Therefore, verification of predicted precipitation for large precipitation events was performed with the ECMWF model. Measured precipitation data were interpolated on a regular grid and compared with the results from the ECMWF model. The deviation in predicted precipitation from interpolated measurements is shown with the model bias resulting from the inability of the model to predict the precipitation correctly and a bias for horizontal resolution of the model and natural variability of precipitation.
Flood forecasting using a fully distributed model: application of the TOPKAPI model to the Upper Xixian Catchment
Authors: Liu Z. , Martina M. L. V. , Todini E.
Published: April 2010

Abstract. TOPKAPI is a physically-based, fully distributed hydrological model with a simple and parsimonious parameterisation. The original TOPKAPI is structured around five modules that represent evapotranspiration, snowmelt, soil water, surface water and channel water, respectively. Percolation to deep soil layers was ignored in the old version of the TOPKAPI model since it was not important in the basins to which the model was originally applied. Based on published literature, this study developed a new version of the TOPKAPI model, in which the new modules of interception, infiltration, percolation, groundwater flow and lake/reservoir routing are included. This paper presents an application study that makes a first attempt to derive information from public domains through the internet on the topography, soil and land use types for a case study Chinese catchment - the Upper Xixian catchment in Huaihe River with an area of about 10000 km2, and apply a new version of TOPKAPI to the catchment for flood simulation. A model parameter value adjustment was performed using six months of the 1998 dataset. Calibration did not use a curve fitting process, but was chiefly based upon moderate variations of parameter values from those estimated on physical grounds, as is common in traditional calibration. The hydrometeorological dataset of 2002 was then used to validate the model, both against the outlet discharge as well as at an internal gauging station. Finally, to complete the model performance analysis, parameter uncertainty and its effects on predictive uncertainty were also assessed by estimating a posterior parameter probability density via Bayesian inference.
Flood forecasting using medium-range probabilistic weather prediction
Authors: Gouweleeuw B. T. , Thielen J. , Franchello G. , De Roo A. P. J. , Buizza R.
Published: April 2010

Abstract. Following the developments in short- and medium-range weather forecasting over the last decade, operational flood forecasting also appears to show a shift from a so-called single solution or 'best guess' deterministic approach towards a probabilistic approach based on ensemble techniques. While this probabilistic approach is now more or less common practice and well established in the meteorological community, operational flood forecasters have only started to look for ways to interpret and mitigate for end-users the prediction products obtained by combining so-called Ensemble Prediction Systems (EPS) of Numerical Weather Prediction (NWP) models with rainfall-runoff models. This paper presents initial results obtained by combining deterministic and EPS hindcasts of the global NWP model of the European Centre for Medium-Range Weather Forecasts (ECMWF) with the large-scale hydrological model LISFLOOD for two historic flood events: the river Meuse flood in January 1995 and the river Odra flood in July 1997. In addition, a possible way to interpret the obtained ensemble based stream flow prediction is proposed.
Utility of different data types for calibrating flood inundation models within a GLUE framework
Authors: Hunter N. M. , Bates P. D. , Horritt M. S. , De Roo A. P. J. , Werner M. G. F.
Published: April 2010

Abstract. To translate a point hydrograph forecast into products for use by environmental agencies and civil protection authorities, a hydraulic model is necessary. Typical one- and two-dimensional hydraulic models are able to predict dynamically varying inundation extent, water depth and velocity for river and floodplain reaches up to 100 km in length. However, because of uncertainties over appropriate surface friction parameters, calibration of hydraulic models against observed data is a necessity. The value of different types of data is explored in constraining the predictions of a simple two-dimensional hydraulic model, LISFLOOD-FP. For the January 1995 flooding on the River Meuse, The Netherlands, a flow observation data set has been assembled for the 35-km reach between Borgharen and Maaseik, consisting of Synthetic Aperture Radar and air photo images of inundation extent, downstream stage and discharge hydrographs, two stage hydrographs internal to the model domain and 84 point observations of maximum free surface elevation. The data set thus contains examples of all the types of data that potentially can be used to calibrate flood inundation models. 500 realisations of the model have been conducted with different friction parameterisations and the performance of each realisation has been evaluated against each observed data set. Implementation of the Generalised Likelihood Uncertainty Estimation (GLUE) methodology is then used to determine the value of each data set in constraining the model predictions as well as the reduction in parameter uncertainty resulting from the updating of generalised likelihoods based on multiple data sources.
Biogeochemistry of the Kem' River estuary, White Sea (Russia)
Authors: Shevchenko V. R. , Dolotov Y. S. , Filatov N. N. , Alexeeva T. N. , Filippov A. S. , Nöthig E.-M. , Novigatsky A. N. , Pautova L. A. , Platonov A. V. , Politova N. V. , Rat'kova T. N. , Stein R.
Published: April 2010

Abstract. The biogeochemistry of the river-sea interface was studied in the Kem' River (the largest river flowing to the White Sea from Karelian coast) estuary and adjacent area of the White Sea onboard the RV "Ekolog" in summer 2001, 2002 and 2003. The study area can be divided into 3 zones: I - the estuary itself, with water depth from 1 to 5m and low salinity in the surface layer (salinity is lower than 0.2psu in the Kem' River and varies from 15 to 20psu in outer part of this zone); II - the intermediate zone with depths from 5 to 10m and salinity at the surface from 16 to 22psu; III - the marine zone with depths from 10 to 29 m and salinity 21-24.5psu. Highest concentrations of the suspended particulate matter (SPM) were registered in the Kem' mouth (5-7mg/l). They sharply decreased to values <1mg/l towards the sea. At beginning of July 2001, particulate organic carbon (POC) concentration in the river mouth was 404µg/l and POC content in total SPM was 5.64%. In the marine part of the studied area the POC concentration varied from 132 to 274µg/l and the POC contents in suspended matter increased to 19-52.6%. These studies show, that the majority of riverborne suspended matter in the Kem' estuary deposits near the river mouth within the 20psu isohaline, where sedimentation of the suspended matter takes place. The role of fresh-water phytoplankton species decreases and the role of marine species increases from the river to sea and the percentage of green algae decreases and the role of diatoms increases. The organic carbon (Corg) to nitrogen (N) ratio (Corg/N) in both suspended matter and bottom sediments decreases from the river to the marine part of the mixing zone (from 8.5 to 6.1 in the suspended matter and from 14.6 to 7.5 in the bottom sediments), demonstrating that content of terrestrial-derived organic matter decreases and content of marine organic matter increases from the river mouth to the sea. The Kem' estuary exhibits a similar character of biogeochemial processes as in the large Arctic estuaries, but the scale of these processes (amount of river input of SPM, POC, area of estuaries) is different.
Rainfall and throughfall chemistry in the Atlantic Forest: a comparison between urban and natural areas (São Paulo State, Brazil)
Authors: Forti M. C. , Bicudo D. C. , Bourotte C. , de Cicco V. , Arcova F. C. S.
Published: April 2010

Abstract. Two areas in the Atlantic Forest (São Paulo State, Brazil), with contrasting environments in respect of human occupation, were monitored from 1999 to 2001. One area named PEFI (23°38'08''-23°40'18'' S and 46°36'48''-46°38'00'' W) at an altitude of 798 m a.s.l., 526.4 ha in area and about 50 km from the sea, lies in a State Park within the largest metropolis of South America - São Paulo. The other area, named CUNHA (between 23°13'18'' and 23°16'10'' S and 45°02'53'' and 45°05'15'' W) about 1050 m a.s.l. with an area of 2854 ha and about 15 km from the sea, is also within a State Park in the Atlantic Forest, but is surrounded by rural areas and small villages. For each area, the rainfall and throughfall chemistry were examined and pH and Na+, K+, Mg2+, Ca2+, NH4+, Cl-, NO3- and SO42- as well as trace metals were determined. Compared with PEFI, CUNHA is characterised by low chemical fluxes and the largest differences are for the ions such as Ca2+, H+, NO3- and SO42- which are mainly anthropogenic in origin. Differences in throughfall chemical fluxes are linked to the nutritional status of the trees.
The impact of broadleaved woodland on water resources in lowland UK: II. Evaporation estimates from sensible heat flux measurements over beech woodland and grass on chalk sites in Hampshire
Authors: Roberts J. , Rosier P. , Smith D. M.
Published: April 2010

Abstract. The impact on recharge to the Chalk aquifer of substitution of broadleaved woodland for pasture is a matter of concern in the UK. Hence, measurements of energy balance components were made above beech woodland and above pasture, both growing on shallow soils over chalk in Hampshire. Latent heat flux (evaporation) was calculated as the residual from these measurements of energy balances in which sensible heat flux was measured with an eddy correlation instrument that determined fast response vertical wind speeds and associated temperature changes. Assessment of wind turbulence statistics confirmed that the eddy correlation device performed satisfactorily in both wet and dry conditions. There was excellent agreement between forest transpiration measurements made by eddy correlation and stand level tree transpiration measured with sap flow devices. Over the period of the measurements, from March 1999 to late summer 2000, changes in soil water content were small and grassland evaporation and transpiration estimated from energy balance-eddy flux measurements were in excellent agreement with Penman estimates of potential evaporation. Over the 18-month measurement period, the cumulative difference between broadleaved woodland and grassland was small but evaporation from the grassland was 3% higher than that from the woodland. In the springs of 1999 and 2000, evaporation from the grassland was greater than that from the woodland. However, following leaf emergence in the woodland, the difference in cumulative evaporation diminished until the following spring.
The impact of broadleaved woodland on water resources in lowland UK: III. The results from Black Wood and Bridgets Farm compared with those from other woodland and grassland sites
Authors: Roberts J. , Rosier P.
Published: April 2010

Abstract. In the United Kingdom the planting of broadleaved woodland has led to concerns about the impact on water resources. Comparative studies, typically using soil water measurements, have been established to compare water use of broadleaved woodland and grassland. The diversity of outcomes from these studies makes it difficult to make any consistent prediction of the hydrological impact of afforestation. Most studies have shown greater drying of soils under broadleaved woodland than under grass. However, two studies in a beech wood growing on shallow soils above chalk at Black Wood, Micheldever, Hampshire showed little overall difference between broadleaved woodland and grass, either in soil water abstraction or in evaporation. Two factors are thought to contribute to the different results from Black Wood. It is known that evaporation can be considerably enhanced at the edges of woodlands or in small areas of woodlands. The studies at Black Wood were made well within a large area of fairly uniform woodland. Other studies in which a difference occurred in soil drying between broadleaved woodland and grass used measurements made in small areas of woodlands or at woodland edges. Another important difference between comparison of woodland at Black Wood and grassland growing nearby, also on shallow soils above Chalk, compared to other broadleaved woodland/grass comparisons, growing on other geologies, is the influence of the Chalk. Although vegetation such as grass (and woodland) does not populate the chalk profusely with roots, water can be removed from the Chalk by the roots which proliferate at the soil/chalk interface and which can generate upward water movement within the Chalk. Published work showed that only in a very dry summer did the evaporation from grass growing on shallow soils above chalk fall below potential. In broadleaved woodland/grass comparisons on non-chalky soils it is possible that moisture deficits in the soil below the grass may reach critical levels and reduce evaporation below that of the woodland with which it is being compared.
Lanthanum, cerium, praseodymium and yttrium in waters in an upland acidic and acid sensitive environment, mid-Wales
Authors: Nea C.
Published: April 2010

Abstract. The less than 0.45 mm filterable lanthanum (La), cerium (Ce), praseodymium (Pr) and yttrium (Y) concentrations in rainfall, cloud water, stream and groundwater in the upper River Severn catchments of mid-Wales are presented, based on up to ten years of weekly data. Results show that for rainfall, there is enrichment in the rare earth (RE) elements, especially under conditions of small volume of catch. However, within the correlations, there is a 'forked' relationship, with one line of high La, Ce and Pr with low Y, corresponding to clear pollutant events and the other with relatively low La, Ce and Pr and higher Y to background conditions. Cloud water and stream waters show a simpler relationship indicating two types of source. Cloud, stream and ground water show no split in pattern, with singular linear relationships between the rare La, Ce, Pr and Y. However, in many cases the monitoring of the streams and groundwaters post-dates the rainfall period with high pollutant Ce inputs. RE element concentrations vary systematically, in general decreasing with increasing volume of catch for cloud-water. For the streams, occasionally, there are relatively high Ce and La concentrations (up to about a tenth the maximum in rainfall), which occur in the same year as the corresponding high values in rainfall. Apart from these anomalous periods, RE element concentrations increase with decreasing pH and increasing aluminium concentrations; RE elements are mobilised under acidic conditions. The river waters are particularly enriched in Y relative to La, Ce and Pr, both in terms of average concentrations and values normalised to standard continental shales. The RE element level in the streams is variable and seems to be linked to the main soil types within the catchment; gleys in particular show higher concentrations than their peat and podzolic counterparts. On average, groundwaters are enriched in the RE elements relative to the stream but the link with pH and aluminium observed in the stream is much weaker.
Uncertainty of solute flux estimation in ungauged small streams: potential implications for input-output nutrient mass balances at stream reach scale
Authors: Butturini A.
Published: April 2010

Abstract. Input-output mass balances within stream reaches provide in situ estimates of stream nutrient retention/release under a wide spectrum of hydrological conditions. Providing good estimates of the mass balances for nutrients depends on precise hydrological monitoring and good chemical characterisation of stream water at the input and output ends of the stream reach. There is a need to optimise the hydrological monitoring and the frequencies of water sampling to yield precise annual mass balances, so as to avoid undue cost - high resolution monitoring and subsequent chemical analysis can be labour intensive and costly. In this paper, simulation exercises were performed using a data set created to represent the instantaneous discharge and solute dynamics at the input and output ends of a model stream reach during a one year period. At the output end, stream discharge and water chemistry were monitored continuously, while the input end was assumed to be ungauged; water sampling frequency was changed arbitrarily. Instantaneous discharge at the ungauged sampling point was estimated with an empirical power model linking the discharge to the catchment area (Hooper, 1986). The model thus substitutes for the additional gauge station. Simulations showed that 10 days was the longest chemical sampling interval which could provide reach annual mass balances of acceptable precision. Presently, the relationship between discharge and catchment area is usually assumed to be linear but simulations indicate that small departures from the linearity of this relationship could cause dramatic changes in the mass balance estimations.
Light limitation of primary production in high latitude reservoirs
Authors: Sahlberg J. , Rahm L.
Published: April 2010

Abstract. To explore the effects of vertical mixing on the primary production in a northern reservoir, a Lagrangian particle dispersion model was coupled to a 1-D reservoir model where the vertical mixing was calculated using a k-ε model together with an empirically-based deep-water eddy viscosity. The primary production of each phytoplankton cell is assumed to be a function of the ambient light and not to be nutrient limited. The photoadaption follows first-order kinetics where the photoadaptive variables, a, b, and Pm, describe the coefficients of the photosynthesis-irradiance curve. The model is applied to the northern reservoir Akkajaure, which is strongly regulated with a mean and maximum depth of 30 m and 100 m respectively. Based on the release of 1000 particles (plankton), the model calculated the mean primary production of each plankton, during four different growing seasons. Vertical mixing has a substantial effect on the vertical distribution of phytoplankton and, thus, on the primary production in a reservoir. It was found that primary production was greater in a cold summer with weak stratification than in a warm summer when the reservoir was more stratified.
A conceptual glacio-hydrological model for high mountainous catchments
Authors: Schaefli B. , Hingray B. , Niggli M. , Musy A.
Published: April 2010

Abstract. In high mountainous catchments, the spatial precipitation and therefore the overall water balance is generally difficult to estimate. The present paper describes the structure and calibration of a semi-lumped conceptual glacio-hydrological model for the joint simulation of daily discharge and annual glacier mass balance that represents a better integrator of the water balance. The model has been developed for climate change impact studies and has therefore a parsimonious structure; it requires three input times series - precipitation, temperature and potential evapotranspiration - and has 7 parameters to calibrate. A multi-signal approach considering daily discharge and - if available - annual glacier mass balance has been developed for the calibration of these parameters. The model has been calibrated for three different catchments in the Swiss Alps having glaciation rates between 37% and 52%. It simulates well the observed daily discharge, the hydrological regime and some basic glaciological features, such as the annual mass balance.
Bringing it all together
Authors: Dooge J. C. I.
Published: April 2010

Abstract. The various elements of the hydrological cycle are discussed in outline from the point of view of making progress in analysis through appropriate simplification of these complex processes. Parallels between stochastic and deterministic analysis and between linear and non-linear conceptual models are emphasised. Reference is made to similarities and contrasts between analysis over the range of scales from the water molecule to the global water balance.
A robust and parsimonious regional disaggregation method for deriving hourly rainfall intensities for the UK
Authors: Maréchal D. , Holman I. P.
Published: April 2010

Abstract. A regional rainfall disaggregation method from daily to hourly intensities is presented for the entire UK, which was developed for use with regionalised hydrological and water quality models. The approach is based on the inter-dependence of the hourly rainfall intensities during a rainfall event. The analysis of 23 229 days with at least 15 mm of precipitation from 238 weather stations throughout the UK allowed regional parameters for climatically homogeneous regions of the UK to be derived for each season. The method reproduces well the main statistical characteristics of the data (mean, minimum and maximum intensity and standard deviation). The method is fully operational, computationally efficient and can be applied to any location throughout the UK.
Effects of spatial variability of precipitation for process-orientated hydrological modelling: results from two nested catchments
Authors: Tetzlaff D. , Uhlenbrook U.
Published: April 2010

Abstract. The importance of considering the spatial distribution of rainfall for process-oriented hydrological modelling is well-known. However, the application of rainfall radar data to provide such detailed spatial resolution is still under debate. In this study the process-oriented TACD (Tracer Aided Catchment model, Distributed) model had been used to investigate the effects of different spatially distributed rainfall input on simulated discharge and runoff components on an event base. TACD is fully distributed (50x50 m2 raster cells) and was applied on an hourly base. As model input rainfall data from up to 11 ground stations and high resolution rainfall radar data from an operational C-band radar were used. For seven rainfall events the discharge simulations were investigated in further detail for the mountainous Brugga catchment (40 km2) and the St. Wilhelmer Talbach (15.2 km2) sub-basin, which are located in the Southern Black Forest Mountains, south-west Germany. The significance of spatial variable precipitation data was clearly demonstrated. Dependent on event characteristics, localized rain cells were occasionally poorly captured even by a dense ground station network, and this resulted in insufficient model results. For such events, radar data can provide better input data. However, an extensive data adjustment using ground station data is required. Therefore, a new method was developed that considers the rainfall intensity distribution. The use of the distributed catchment model allowed further insights into spatially variable impacts of different rainfall estimates. Impacts for discharge predictions are the largest in areas that are dominated by the production of fast runoff components. To conclude, the improvements for distributed runoff simulation using high resolution rainfall radar input data are strongly dependent on the investigated scale, the event characteristics, the existing monitoring network and, last but not least, the applied model.
Characterization of the field saturated hydraulic conductivity on a hillslope: measurement techniques, data sensitivity analysis and spatial correlation modelling
Authors: Fallico C. , Migliari E. , Troisi S.
Published: April 2010

Abstract. In the context of studies aiming at the estimation of effective parameters for unsaturated zone modelling, this work tackles the problem of experimental data quality, considering the large collection of data gathered at an experimental site equipped for unsaturated zone hydraulic monitoring in the alluvial basin of a Calabrian river, in the South of Italy. Focusing attention on field saturated hydraulic conductivity, the in-site measurement techniques by tension disc and pressure ring infiltrometers are considered, pointing out the main indications for the correct use of each measuring approach; laboratory techniques are also considered. Statistical data analysis showed that the measurements performed by tension disc infiltrometer supplied values of hydraulic conductivity which are on average lower and more homogeneous than the values provided by the other measurement techniques considered. Sensitivity analysis was then carried out by Monte Carlo simulation on the parameter sampling achieved by field measurement techniques in order to evaluate the influence of any possible small measurement errors on the data. Sensitivity analysis showed that both ring and disc infiltrometer are tools reliable enough for the in situ measurements of field saturated hydraulic conductivity. Finally, after a data merging procedure giving origin to different sets of data, the spatial correlation structure of field saturated hydraulic conductivity is investigated, using well-known geostatistical techniques.
Landslide susceptibility mapping of Cekmece area (Istanbul, Turkey) by conditional probability
Authors: Duman T. Y. , Can T. , Gokceoglu C. , Nefeslioglu H. A.
Published: April 2010

Abstract. As a result of industrialization, throughout the world, the cities have been growing rapidly for the last century. One typical example of these growing cities is Istanbul. Today, the population of Istanbul is over 10 millions. Depending on this rapid urbanization, new suitable areas for settlements and engineering structures are necessary. For this reason, the Cekmece area, west of the Istanbul metropolitan area, is selected as the study area, because the landslides are frequent in this area. The purpose of the present study is to produce landslide susceptibility map of the selected area by conditional probability approach. For this purpose, a landslide database was constructed by both air – photography and field studies. 19.2% of the selected study area is covered by landslides. Mainly, the landslides described in the area are generally located in the lithologies including the permeable sandstone layers and impermeable layers such as claystone, siltstone and mudstone layers. When considering this finding, it is possible to say that one of the main conditioning factors of the landslides in the study area is lithology. In addition to lithology, many landslide conditioning factors are considered during the landslide susceptibility analyses. As a result of the analyses, the class of 5–10° of slope, the class of 180–225 of aspect, the class of 25–50 of altitude, Danisment formation of the lithological units, the slope units of geomorphology, the class of 800–1000 m of distance from faults (DFF), the class of 75–100 m of distance from drainage (DFD) pattern, the class of 0–10m of distance from roads (DFR) and the class of low or impermeable unit of relative permeability map have the higher probability values than the other classes. When compared with the produced landslide susceptibility map, most of the landslides identified in the study area are found to be located in the most (54%) and moderate (40%) susceptible zones. This assessment is also supported by the performance analysis applied at end of the study. As a consequence, the landslide susceptibility map produced herein has a valuable tool for the planning purposes.
Research on evaporation of Taiyuan basin area by using remote sensing
Authors: Jin X. , Wan L. , Su Z.
Published: April 2010

Abstract. Taiyuan basin is enclosed by hills and mountains, located in the middle of Shanxi province, standing between longitudes 111°40'–113°00'E and latitude 37°00'–38°00'N. With various types and wide distribution, the mineral resources are very abundant in this basin area. However, there is a great shortage of water resources. Due to continual fall of groundwater level caused by excessive extraction of ground water, some severe environmental problems are induced in this area, such as ground subsidence, etc. The goal of this paper is to estimate the spatial distribution of actual evaporation over the basin by using remote sensing data. The Surface Energy Balance System (SEBS) has been developed (Su, 2001, 2002). Using visible and infrared satellite remote sensing data, SEBS is based on land surface energy balance theory combined with the in-situ meteorological data or the product of atmospheric numerical model to estimate land surface turbulent flux and the relative evaporation at different scales. SEBS was served as the core methodology of this paper and was used for evaporation estimation. On the basis of hydro-geological data and NOAA satellite data, the SEBS was used in this paper for the estimation of actual evaporation of Taiyuan basin. The spatial distribution of the evaporative fraction and daily evaporation over the basin area was shown. On the other hand, the difference of land surface parameters and evaporation for various target types in the basin area was discussed.
An integrated geological, hydrogeological and geophysical approach to the characterisation of the aquifer in a contaminated site
Authors: Di Paola M. A. , Margiotta S. , Mazzone F. , Negri S.
Published: April 2010

Abstract. This work sets out a physical – stratigraphical reconstruction of the superficial aquifer in the Brindisi area; this site is recognized to be at significant environmental risk (Law no. 426/98) by the Italian government. Geological, hydrogeological and geophysical methodologies were applied. The geological characterisation consisted of surface and subsoil surveys. The existing stratigraphical, geotechnical and hydrogeological data were collected, processed and homogenised, and the information inserted in a database managed with a specific software (arcview). Hydrogeological surveys were conducted in a number of boreholes uniformly distributed over the studied area. Geophysical prospecting was conducted in the most industrialized part of the area, adjacent to a combined industrial road/conveyor belt – the "Asse Attrezzato" – in order to better describe the site and evaluate the impact of this structure on the environment. This research enabled us to characterise the superficial aquifer of the Brindisi area. The groundwater is of the phreatic type. In the upper part of the deposit, the presence of low permeability sediments (recent continental deposits) means that the groundwater is confined. Subapennine Clays (Lower Pleistocene), present across the whole of the area, form the impermeable base of the aquifer. The deposits that make up the superficial aquifer vary greatly in their permeability. The greatest permeability is associated with the calcarenite deposits (Terraced Deposits, Middle-Upper Pleistocene). The higher the proportion of slime in the granulometric assortment, the lower the permeability of the deposit. The lower section of the aquifer, characterized by the presence of slimy-sandy sediments (Brindisi sands, Lower-Middle Pleistocene), has a lower permeability. The results of the geophysical investigations enabled us to reconstruct in detail the lateral and vertical lithological variations of the geological formations. Furthermore, by supplementing the data from boreholes (direct surveys), the geophysical surveys proved to be useful in that they reduce the need for perforations of the ground, which are potential conduits of pollution.
Variability in riparian zone potential and actual evapotranspiration in a 1st order agricultural catchment in Southern Ontario, Canada
Authors: Petrone R. M. , Smith C. , English M. C.
Published: April 2010

Abstract. Micrometeorological and hydrological measurements were made over one growing season using automatic weather stations and weighing lysimeters at several locations within a multiple land-use agricultural catchment in Southern Ontario. This paper compares modelled potential evapotranspiration (PET) and measured actual evapotranspiration (AET) values obtained from the soil weighing lysimeters, and determines the spatial variability in riparian zone AET in a multiple land-use agricultural watershed in Southern Ontario. Two sites were chosen in two different riparian areas of the watershed, representing the surface conditions dominant in the upper and lower reaches of the basin. The results indicated that AET was higher in the northern end of the basin than in the southern portion of the basin, while the hydrological and energy balance components were similar at both sites. The causes of the different rates are attributed to the surrounding vegetation on adjacent fields and the differing wind regimes.
Hydrogeomorphic controls on runoff in a temperate swamp
Authors: Kaufman S. C. , Waddington J. M. , Branfireun B. A.
Published: April 2010

Abstract. Beverly Swamp, a high-order forested temperate wetland near Hamilton, Ontario was studied during wet (2000) and dry (2001) summer seasons to determine and compare runoff pathways and storage mechanisms in two hydrogeomorphically different sub-basins. A channelized (Fletcher Swamp) and an unchannelized (Spencer Swamp) sub-basin were examined. During wet periods, the Fletcher Swamp displayed a consistent interaction between the wetland and stream, resulting in a gaining stream, maintaining a lateral hydrological connection and yielding high runoff ratios. When dry periods dominated, water tables dropped low enough in the Fletcher Swamp such that water moved from the stream channel into the underlying substrate, creating a lateral hydrological disconnection between the stream and wetland. This disconnection reduced runoff ratios during storm events. The Spencer Swamp, with no well-defined stream channel, relied on overland flow and a longitudinal hydrological connection to deliver water to the sub-basin outflow. This connection was maintained in the wet season (2000) but ceased in the dry season (2001) despite consistent inputs from an upstream reservoir. Available depression storage prevented overland flow during 2001, and although a shallow groundwater flux maintained discharge for a period of time, drought conditions led to zero discharge at the sub-basin outflow in mid-summer. Runoff ratios were reduced dramatically from season to season as a result of this disconnection. Implications of these hydrogeomorphic runoff controls on wetland biogeochemistry are discussed.
Downscaled Rainfall Prediction Model (DRPM) using a Unit Disaggregation Curve (UDC)
Authors: Tantanee S. , Patamatamakul S. , Oki T. , Sriboonlue V. , Prempree T.
Published: April 2010

Abstract. This study was undertaken to identify the process for generating finer time scaled rainfall from higher time scaled data. The Downscaled Rainfall Prediction Model (DRPM) using the technique of unit disaggregation curve (UDC) was developed under the concept of coupling the stochastic autoregressive (AR) model with a wavelet filter and disaggregation model. Sequences of the number of rainy days and monthly rainfall were simulated from 52-year rainfall records at 4 stations in the northeastern part of Thailand. Compared with actual rainfall sequences, the 30 year generated sequences provided R-square values of 0.47-0.60. The model was applied to forecast the number of rainy days and monthly rainfall for the year of 2002. When compared with actual records the prediction model provided R-square values of 0.50 to 0.79.
A conceptual glacio-hydrological model for high mountainous catchments
Authors: Schaefli B. , Hingray B. , Niggli M. , Musy A.
Published: April 2010

Abstract. In high mountainous catchments, the spatial precipitation and therefore the overall water balance is generally difficult to estimate. The present paper describes the structure and calibration of a semi-lumped conceptual glacio-hydrological model for the joint simulation of daily discharge and annual glacier mass balance that represents a better integrator of the water balance. The model has been developed for climate change impact studies and has therefore a parsimonious structure; it requires three input times series – precipitation, temperature and potential evapotranspiration – and has 7 parameters to calibrate. A multi-signal approach considering daily discharge and – if available – annual glacier mass balance has been developed for the calibration of these parameters. The model has been calibrated for three different catchments in the Swiss Alps having glaciation rates between 37% and 52%. It simulates well the observed daily discharge, the hydrological regime and some basic glaciological features, such as the annual mass balance.