How to improve the representation of hydrological processes in SWAT for a lowland catchment – temporal analysis of parameter sensitivity and model performance          下载免费PDF全文

Björn Guse  Dominik E. Reusser  Nicola Fohrer 《水文研究》2014,28(4):2651-2670

Model diagnostic analyses help to improve the understanding of hydrological processes and their representation in hydrological models. A detailed temporal analysis detects periods of poor model performance and model components with potential for model improvements, which cannot be found by analysing the whole discharge time series. In this study, we aim to improve the understanding of hydrological processes by investigating the temporal dynamics of parameter sensitivity and of model performance for the Soil and Water Assessment Tool model applied to the Treene lowland catchment in Northern Germany. The temporal analysis shows that the parameter sensitivity varies temporally with high sensitivity for three groundwater parameters (groundwater time delay, baseflow recession constant and aquifer fraction coefficient) and one evaporation parameter (soil evaporation compensation factor). Whereas the soil evaporation compensation factor dominates in baseflow and resaturation periods, groundwater time delay, baseflow recession constant and aquifer fraction coefficient are dominant in the peak and recession phases. The temporal analysis of model performance identifies three clusters with different model performances, which can be related to different phases of the hydrograph. The lowest performance, when comparing six performance measures, is detected for the baseflow cluster. A spatially distributed analysis for six hydrological stations within the Treene catchment shows similar results for all stations. The linkage of periods with poor model performance to the dominant model components in these phases and with the related hydrological processes shows that the groundwater module has the highest potential for improvement. This temporal diagnostic analysis enhances the understanding of the Soil and Water Assessment Tool model and of the dominant hydrological processes in the lowland catchment. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

Water level observations from unmanned aerial vehicles for improving estimates of surface water–groundwater interaction          下载免费PDF全文

Filippo Bandini  Michael Butts  Torsten Vammen Jacobsen  Peter Bauer‐Gottwein 《水文研究》2017,31(24):4371-4383

Integrated hydrological models are usually calibrated against observations of river discharge and piezometric head in groundwater aquifers. Calibration of such models against spatially distributed observations of river water level can potentially improve their reliability and predictive skill. However, traditional river gauging stations are normally spaced too far apart to capture spatial patterns in the water surface, whereas spaceborne observations have limited spatial and temporal resolution. Unmanned aerial vehicles can retrieve river water level measurements, providing (a) high spatial resolution; (b) spatially continuous profiles along or across the water body, and (c) flexible timing of sampling. A semisynthetic study was conducted to analyse the value of the new unmanned aerial vehicle‐borne datatype for improving hydrological models, in particular estimates of groundwater–surface water (GW–SW) interaction. Mølleåen River (Denmark) and its catchment were simulated using an integrated hydrological model (MIKE 11–MIKE SHE). Calibration against distributed surface water levels using the Differential Evolution Adaptive Metropolis algorithm demonstrated a significant improvement in estimating spatial patterns and time series of GW–SW interaction. After water level calibration, the sharpness of the estimates of GW–SW time series improves by ~50% and root mean square error decreases by ~75% compared with those of a model calibrated against discharge only.  相似文献   

Comparison of artificial neural network models for hydrologic predictions at multiple gauging stations in an agricultural watershed   总被引：1，自引：0，他引：1  

E. Mutlu  I. Chaubey  H. Hexmoor  S. G. Bajwa 《水文研究》2008,22(26):5097-5106

This paper reports on an evaluation of the use of artificial neural network (ANN) models to forecast daily flows at multiple gauging stations in Eucha Watershed, an agricultural watershed located in north‐west Arkansas and north‐east Oklahoma. Two different neural network models, the multilayer perceptron (MLP) and the radial basis neural network (RBFNN), were developed and their abilities to predict stream flow at four gauging stations were compared. Different scenarios using various combinations of data sets such as rainfall and stream flow at various lags were developed and compared for their ability to make flow predictions at four gauging stations. The input vector selection for both models involved quantification of the statistical properties such as cross‐, auto‐ and partial autocorrelation of the data series that best represented the hydrologic response of the watershed. Measured data with 739 patterns of input–output vector were divided into two sets: 492 patterns for training, and the remaining 247 patterns for testing. The best performance based on the RMSE, R² and CE was achieved by the MLP model with current and antecedent precipitation and antecedent flow as model inputs. The MLP model testing resulted in R² values of 0·86, 0·86, 0·81, and 0·79 at the four gauging stations. Similarly, the testing R² values for the RBFNN model were 0·60, 0·57, 0·58, and 0·56 for the four gauging stations. Both models performed satisfactorily for flow predictions at multiple gauging stations, however, the MLP model outperformed the RBFNN model. The training time was in the range 1–2 min for MLP, and 5–10 s for RBFNN on a Pentium IV processor running at 2·8 GHz with 1 MB of RAM. The difference in model training time occurred because of the clustering methods used in the RBFNN model. The RBFNN uses a fuzzy min‐max network to perform the clustering to construct the neural network which takes considerably less time than the MLP model. Results show that ANN models are useful tools for forecasting the hydrologic response at multiple points of interest in agricultural watersheds. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

Trends and multi‐annual variability of water temperatures in the river Danube,Serbia          下载免费PDF全文

Biljana Basarin  Tin Lukić  Dragoslav Pavić  Robert L. Wilby 《水文研究》2016,30(18):3315-3329

The relationship between air (Ta) and water temperature (Tw) is very important because it shows how the temperature of a water body might respond to future changes in surface Ta. Mean monthly Tw records of three gauging stations (Bezdan, Bogojevo i Veliko Gradi?te) were analysed alongside mean monthly discharge (Q) for the same stations. Additionally, Ta series from two meteorological stations (Sombor and Veliko Gradi?te) were correlated with Tw variations over the period 1950–2012. Locally weighted scatter point smoothing (LOWESS) was used to investigate long‐term trends in the raw data, alongside the Mann–Kendall (MK) trend test. Trend significance was established using Yue–Pilon's pre‐whitening approaches to determine trends in climate data. Also, the rescaled adjusted partial sums (RAPS) method was used to detect dates of possible changes in the time series. Statistically significant warming trends were observed for annual and seasonal minimum and maximum Tw at all investigated sites. The strongest warming was observed at Bogojevo gauging station for seasonal maximum Tw, with +0.05 °C per year on average. RAPS established that the trend began in the 1980s. This behaviour is linked to climate patterns in the North and East Atlantic which determine the amount of heat advected onto mainland Europe. Statistically significant correlations were found for all Tw on an annual basis. Overall, the strongest correlations (p < 0.01) between Tw residuals and the North Atlantic Oscillation (NAO) were recorded for the winter period. These findings suggest possible predictability of Tw over seasonal time‐scales. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

Insight into variability of spring and flash flood events in Lithuania     

Diana Meilutytė-Lukauskienė  Vytautas Akstinas  Jūratė Kriaučiūnienė  Diana Šarauskienė  Aldona Jurgelėnaitė 《Acta Geophysica》2017,65(1):89-102

In this research, variability of spring (from 1 March to 30 May) and flash (from 1 June to 30 November) floods in rivers of different regions was analysed. The territory of Lithuania is divided into three regions according to hydrological regime of the rivers: Western, Central, and Southeastern. The maximum river discharge data of spring and flash floods [a total of 31 water gauging stations (WGS)] were analysed. Comparison of the data of four periods (1922–2013, 1941–2013, 1961–2013, and 1991–2013) with the data of the reference period (1961–1990) was performed. Analysis included the longest discharge data set of the Nemunas River at Smalininkai WGS (1812–2013) as well. Mixed patterns of flood changes in Lithuanian rivers were detected. The analysis of flood discharges of the Nemunas River indicated that both spring and flash floods in Lithuania were getting smaller.  相似文献   

Lichens and the determination of river channel capacity     

Ken J. Gregory 《地球表面变化过程与地形》1976,1(3):273-285

The identification of channel capacity associated with a particular frequency of peak discharges is necessary for discharge estimation for planning purposes at ungauged sites. Although lichen limits have been suggested to be useful for this purpose, previous studies have not elaborated their hydrological significance. Lichen limits are clearly defined on the sides of rock channels in New England. Australia and they are analyzed in relation to discharge at 6 gauging stations with up to 52 years of continuous record. It is demonstrated that the lowest lichen limit is maintained by peak discharges which occur on average at least once or twice each year. Recurrence intervals based on Annual Series and on Annual Exceedance Series are calculated and for the annual series are fairly consistent for the lowest lichen limit and range from 1·14 to 1·37 years. Lichenometry can be applied to the analysis of river channels in relation to the frequency of peak discharges. By reference to growth curves based upon lichens on Armidale tombstones it is shown that lichenometry may be employed to indicate dates for channel modification due to the removal of blocks and to dam construction and also to date the rock surface between lichen limits. Detailed analysis of the record from gauging stations indicates that where several lichen limits occur in a channel cross section each limit is related to periods when peak discharges exceeded the limits on at least 5 occasions. The lichen-free surfaces were then recolonized by Parmelia spp. and the size of the lichen thalli indicates the time elapsing since these frequent high discharges.  相似文献   

Regional scale rainfall–runoff modeling using VARX–MGARCH approach     

Farshad?FathianEmail authorView author&#;s OrcID profile  Ahmad?Fakheri-Fard  Reza?Modarres  P.?H.?A.?J.?M.?van Gelder 《Stochastic Environmental Research and Risk Assessment (SERRA)》2018,32(4):999-1016

Multivariate time series modeling approaches are known as useful tools for describing, simulating, and forecasting hydrologic variables as well as their changes over the time. These approaches also have temporal and cross-sectional spatial dependence in multiple measurements. Although the application of multivariate linear and nonlinear time series approaches such as vector autoregressive with eXogenous variables (VARX) and multivariate generalized autoregressive conditional heteroscedasticity (MGARCH) models are commonly used in financial and economic sciences, these approaches have not been extensively used in hydrology and water resources engineering. This study employed VARX and VARX–MGARCH approaches in modeling mean and conditional heteroscedasticity of daily rainfall and runoff records in the basin of Zarrineh Rood Dam, Iran. Bivariate diagonal VECH (DVECH) model, as a main type of MGARCH, shows how the conditional variance–covariance and conditional correlation structure vary over the time between residuals series of the fitted VARX. For this purpose, five model fits, which consider different combinations of twofold rainfall and runoff, including both upstream and downstream stations, have been investigated in the present study. The VARX model, with different orders, was applied to the daily rainfall–runoff process of the study area in each of these model fits. The Portmanteau test revealed the existence of conditional heteroscedasticity in the twofold residuals of fitted VARX models. Therefore, the VARX–DVECH model is proposed to capture the heteroscedasticity existing in the daily rainfall–runoff process. The bivariate DVECH model indicated both short-run and long-run persistency in the conditional variance–covariance matrix related to the twofold innovations of rainfall–runoff processes. Furthermore, the evaluation criteria for the VARX–DVECH model revealed the improvement of VARX model performance.  相似文献   

Empirical assessment of flood wave celerity–discharge relationships at local and reach scales     

Aline Meyer  Ayan Santos Fleischmann  Walter Collischonn  Rodrigo Paiva  Pedro Jardim 《水文科学杂志》2013,58(15-16):2035-2047

ABSTRACT

An accurate comprehension of celerity (flood wave speed) dynamics is a key step for understanding flood wave propagation in rivers. We present the results of empirically estimated celerity values in 12 Brazilian rivers, and analyse the behaviour of celerity–discharge relationships (CxQ). Celerity was estimated with a reach-scale (RS) method, based on the peak travel time between stations; and with a local-scale (LS) method, based on the derivative of discharge–cross-section area relationships surveyed at gauging stations. The results indicate that the magnitudes of celerity values obtained by the methods are reasonably comparable, and can rarely be considered constant, varying with river discharge. Three reaches presented differing CxQ relationships at local and reach scales, which suggests that in situ cross-sections at gauging stations should not be extrapolated as representative of the whole reach for flood routing studies, and that CxQ relationship assessments might provide relevant insights for hydrological modelling.  相似文献   

Validation of predicted meteorological drought in California using analogous orbital geometries          下载免费PDF全文

Messele Zewdie Ejeta 《水文研究》2014,28(11):3703-3713

Recent studies have uncovered the predictability of hydrological conditions on Earth, based on an analysis of long‐term precipitation data in California and analogous orbital forcings during different years that are separated by Saros cycles. With similar orbital geometries of the Earth and Moon, water years 1976 and 1994, which are one and two Saros cycles apart from water year 2012, respectively, were both Critically Dry years in California, according to the California Department of Water Resources’ water year type classification. Further analysis of precipitation data at a cross section of gauging stations across the U.S. during water years 1976 and 1994 reinforces the previously observed association between analogous orbital forcings and hydrological conditions on earth. The current work is a validation of predicted meteorological drought in California during water year 2012 using: (1) real‐time precipitation data collected from a cross section of gauging stations across California, and (2) estimated full natural flows of eight major rivers in California. The data for these years were analyzed and found to have a high level of correlation. The results of the current work provide a significant mark in the validation exercises of the recent novel finding of the predictability of earth's meteorological and hydrological variability. Continued studies and mapping of observed hydrological conditions globally in the coming years using this approach will be highly valuable for sustainable water resources engineering and various other applications. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献