共查询到20条相似文献，搜索用时 906 毫秒
1.
Abstract The runoff regime of glacierized headwater catchments in the Alps is essentially characterized by snow and ice melt. High Alpine drainage basins influence distant downstream catchments of the Rhine River basin. In particular, during the summer months, low-flow conditions are probable with strongly reduced snow and ice melt under climate change conditions. This study attempts to quantify present and future contributions from snow and ice melt to summer runoff at different spatial scales. For the small Silvretta catchment (103 km2) in the Swiss Alps, with a glacierization of 7%, the HBV model and the glacio-hydrological model GERM are applied for calculating future runoff based on different regional climate scenarios. We evaluate the importance of snow and ice melt in the runoff regime. Comparison of the models indicates that the HBV model strongly overestimates the future contribution of glacier melt to runoff, as glaciers are considered as static components. Furthermore, we provide estimates of the current meltwater contribution of glaciers for several catchments downstream on the River Rhine during the month of August. Snow and ice melt processes have a significant direct impact on summer runoff, not only for high mountain catchments, but also for large transboundary basins. A future shift in the hydrological regime and the disappearance of glaciers might favour low-flow conditions during summer along the Rhine. Citation Junghans, N., Cullmann, J. & Huss, M. (2011) Evaluating the effect of snow and ice melt in an Alpine headwater catchment and further downstream in the River Rhine. Hydrol. Sci. J. 56(6), 981–993. 相似文献
2.
Abstract Application of the concept of combining the estimated forecast output of different rainfall-runoff models to yield an overall combined estimated output in the context of real-time river flow forecasting is explored. A Real-Time Model Output Combination Method (RTMOCM) is developed, based on the structure of the Linear Transfer Function Model (LTFM) and utilizing the concept of the Weighted Average Method (WAM) for model output combination. A multiple-input single-output form of the LTFM is utilized in the RTMOCM. This form of the LTFM model uses synchronously the daily simulation-mode model-estimated discharge time series of the rainfall-runoff models selected for combination, its inherent updating structure being used for providing updated combined discharge forecasts. The RTMOCM is applied to the daily data of five catchments, using the simulation-mode estimated discharges of three selected rainfall-runoff models, comprising one conceptual model (Soil Moisture Accounting and Routing Procedure—SMAR) and two black-box models (Linear Perturbation Model—LPM and Linearly-Varying Variable Gain Factor Model—LVGFM). In order to get an indication of the accuracy of the updated combined discharge forecasts relative to the updated discharge forecasts of the individual models, the LTFM is also used for updating the simulation-mode discharge time series of each of the three individual models. The results reveal that the updated combined discharge forecasts provided by the RTMOCM, with parameters obtained by linear regression, can improve on the updated discharge forecasts of the individual rainfall-runoff models. 相似文献
3.
《水文科学杂志》2013,58(6)
Abstract Determining the precipitation phase—rain or snow—is an important factor in modelling discharge in mountainous basins. In a study carried out in the outer tropical Andes Cordillera of Bolivia, half-hourly determination of precipitation phase was obtained by applying a suitable expert system, taking 11 meteorological parameters into consideration that are measured over 21 months at an altitude close to 4800 m. Straightforward relationships between the determined precipitation phase and observed air temperature were analysed in histograms that contain percentage occurrences of snowfall, rainfall and mixed precipitation events for 0.5°C air temperature increments. The graph shows a nearly identical distribution of percentage occurrences of snowfall in the Andes to that on a 1600-m high site in the Swiss Alps. This result suggests that, for hydrological modelling purposes in the outer tropical Andes, the same rain/snow threshold temperature as in the compared Swiss site can be applied. 相似文献
4.
《水文科学杂志》2013,58(2)
Abstract An updating technique is a tool to update the forecasts of mathematical flood forecasting model based on data observed in real time, and is an important element in a flood forecasting model. An error prediction model based on a fuzzy rule-based method was proposed as the updating technique in this work to improve one- to four-hour-ahead flood forecasts by a model that is composed of the grey rainfall model, the grey rainfall—runoff model and the modified Muskingum flow routing model. The coefficient of efficiency with respect to a benchmark is applied to test the applicability of the proposed fuzzy rule-based method. The analysis reveals that the fuzzy rule-based method can improve flood forecasts one to four hours ahead. The proposed updating technique can mitigate the problem of the phase lag in forecast hydrographs, and especially in forecast hydrographs with longer lead times. 相似文献
5.
AbstractData-based mechanistic (DBM) models can offer a parsimonious representation of catchment dynamics. They have been shown to provide reliable accurate flood forecasts in many hydrological situations. In this work, the DBM methodology is applied to forecast flash floods in a small Alpine catchment. Compared to previous DBM modelling studies, the catchment response is rapid. The use of novel radar-derived ensemble quantitative precipitation forecasts based on analogues to drive the DBM model allows the forecast horizon to be increased to a level useful for emergency response. The characterization of the predictive uncertainty in the resulting hydrological forecasts is discussed and a framework for its representation illustrated.
Editor Z.W. Kundzewicz; Guest editor R.J. Moore 相似文献
6.
《水文科学杂志》2013,58(4):642-654
Abstract Soil moisture estimates obtained over large spatial areas will become increasingly available through current and upcoming satellite missions and from numerous land surface parameterization schemes run at global- and continental-scale resolutions. The goal of this research was to evaluate the potential for using macroscale estimates of soil moisture for enhancing streamflow forecasts. Towards this research objective, monthly streamflow estimates were obtained from over 50 gauge locations within the Nelson basin, Canada, for the period 1979–1999. For each streamflow record, multiple linear regression models were used to remove components of the streamflow signal related to previous streamflow, climate teleconnections (e.g. ENSO and AO) and snow water equivalence. Correlations were then assessed between the macroscale soil moisture estimates and the residuals of the multiple linear regression analysis over lead times of one, two and three months. At the one- and two-month lead time, statistically significant relationships between soil moisture and the residuals of streamflow are observed over a large proportion of the gauging locations. The number of catchments with statistically significant relationships decreases significantly after two months and particularly in the months of April—June. This study demonstrates that available macroscale estimates of soil moisture have the potential to enhance streamflow prediction, although further study is suggested to improve upon the soil moisture estimates and their application in a forecast system. 相似文献
7.
ABSTRACT This paper attempts to design statistical models to forecast annual precipitation in the Neuquen and Limay river basins in the Comahue region of Argentina. These forecasts are especially useful as they are used to better organize the operation of hydro-electric dams, the agriculture in irrigated valleys and the safety of the population. In this work, multiple linear regression statistical models are built to forecast mean annual rainfall over the two river basins. Since the maximum precipitation occurs in the winter (June–August), forecasting models have been developed for the beginning of March and for the beginning of June, just before the rainy season starts. The results show that the sea-surface temperatures of the Indian and Pacific oceans are good predictors for March models and explain 42.8% of the precipitation index variance. The efficiency of the models increases in June, adding more predictors related to the autumn circulation. 相似文献
8.
ADIGUN ADE ABIODUN 《水文科学杂志》2013,58(3):321-327
ABSTRACT Because of the scarcity of hydrological data, the planning and design of the Kainji hydro-project has been based on information collected during a very short period. This investigation shows that the inflows into the lake since the project became operative are considerably less than the pre-construction flows of the Niger. A number of the anticipated benefits, especially hydro-electric power, flood control and fisheries are being achieved; others, such as navigation improvement, are still to be fully accomplished. The latter situation can be attributed to the inability of the lake to maintain the expected discharge. The water scarcity at Kainji is directly linked with the drought that has ravaged West Africa for the past three years. This investigation also shows that the power generating ability of Lake Kainji has been over-estimated. Another hydro-power scheme should be initiated to supplement the actual power yield from Kainji. 相似文献
9.
L. SIEGERSTETTER Dipl. Math. 《水文科学杂志》2013,58(3):103-113
SUMMARY Using the Rhine as an example, a method is shown which should render possible long-termp redictions of river-flows to a certain extend on the basis of sufficiently long series of recordings. A necessary condition is to consider hydrological processes under a non-deterministic model, which justifies the application of statistic techniques, f.e. the fitting of suitable probability distribution functions. Since one specific prediction is not possible, a first indication is given on how to draw conclusions from a greater number of forecasts. 相似文献
10.
Kazuyoshi Suzuki Yuji Kodama Taro Nakai Glen E. Liston Kazukiyo Yamamoto Tetsuo Ohata 《水文科学杂志》2013,58(3):443-467
Abstract We simulated snow processes in a forested region with heavy snowfall in Japan, and evaluated both the regional-scale snow distribution and the potential impact of land-use changes on the snow cover and water balances over the entire domain. SnowModel reproduced the snow processes at open and forested sites, which were confirmed by snow water equivalent (SWE) measurements at two intensive observation sites and snow depth measurements at the Automated Meteorological Data Acquisition System sites. SnowModel also reproduced the observed snow distribution (from the MODIS snow cover data) over the simulation domain during thaw. The observed SWE was less at the forested site than at the open site. The SnowModel simulations showed that this difference was caused mainly by differences in sublimation. The type of land use changed the maximum SWE, onset and duration of snowmelt, and the daily snowmelt rate due to canopy snow interception. Citation Suzuki, K., Kodama, Y., Nakai, T., Liston, G. E., Yamamoto, K., Ohata, T., Ishii, Y., Sumida, A., Hara, T. & Ohta, T. (2011) Impact of land-use changes in a forested region with heavy snowfall in Hokkaido, Japan. Hydrol. Sci. J. 56(3), 443–467. 相似文献
11.
The aim of this paper is to assess the relative importance of low flow indicators for the River Rhine and to identify their appropriate temporal lag and resolution. This is done in the context of low flow forecasting with lead times of 14 and 90 days. First, the Rhine basin is subdivided into seven sub‐basins. By considering the dominant processes in the sub‐basins, five low flow indicators were selected: precipitation, potential evapotranspiration, groundwater storage, snow storage and lake storage. Correlation analysis was then carried out to determine the relationship between observed low flows and preselected indicators with varying lags (days) and temporal resolutions (from 1 day to 7 months). The results show that the most important low flow indicators in the Alpine sub‐basins for forecasts with a lead time of 14 days are potential evapotranspiration with a large lag and temporal resolution, and lake levels with a small lag and temporal resolution. In the other sub‐basins groundwater levels with a small lag and temporal resolution are important in addition to potential evapotranspiration with a large lag and temporal resolution. The picture is slightly different for forecasts with a lead time of 90 days. The snow storage in the Alpine sub‐basins and the precipitation in the other sub‐basins also become relevant for low flows. Consequently, the most important low flow indicators in the Alpine sub‐basins for forecasts with a lead time of 90 days are potential evapotranspiration with a large lag and temporal resolution, lake levels with a small lag and temporal resolution and snow storage with a small lag and large temporal resolution. The resultant correlation maps provide appropriate lags and temporal resolutions for indicators to forecast low flows in the River Rhine with different lead times. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
12.
Abstract The study of the radioactive snow gauge has been undertaken in Grenoble in 1962 with the objective to develop, up to the routine operation, an automatic solid state electronic snow gauge, radio transmitting every day. 4 units of a first design, with steady vertical radioactive beam have been operated from 1964, but the limitation of the measurable depth to 4 meters of snow, 1,2 meter of water, was soon found too low in the French Alps. A new type of gauge, with moving horizontal beam, profiling the snow pack, was designed in 1965, and evaluated through the last two years—During the measuring cycle, the source (30 millicuries of Cesium 137) and the G.H. detector are moving up at the same level inside two vertical pipes whose distance is 60 cm and height 6 meters; their speed is related to the pulse rate of the detector. One radio signal is emitted each decimeter during the motion. As soon as the team energes from the snow, it stops and returns back to its starting position under the ground level—the snow depth is indicated by the number of signals, and the density in each decimetric interval by the time elapsed between the signals. The results of the last winter: six months'twice daily telemesured snow profiles are exhibited. International cooperation is welcome to urge development of this device, which is felt the most promising automatic snow surveyor. 相似文献
13.
Abstract Flood forecasts for the Sió and Kapos Rivers in Hungary have been made using gage relations. In order to increase the forecast time advantage procedures have been developed for predicting maximum stage using precipitation data and other variables including soil moisture index. The paper describes the methods for developing forecasting relations involving three variables and four or more variables. The procedures are restricted to flood events caused by summer and autumn-precipitation (ice and snow-melt floods excluded). 相似文献
14.
《水文科学杂志》2013,58(5)
Abstract Abstract Results of studies related to the effect of snow accumulation and snowmelt on river regimes of the central Spanish Pyrenees are presented. Streamflow of the Pyrenean rivers is characterized by low and constant discharges during winter because of accumulation of snow in the basins above 1600 m a.s.l., and high and fluctuating discharges during spring due to snowmelt and rainfall. Regional discharge contrasts have been assessed in relation to the Atlantic influence and the percentage of high altitude areas in each basin. In most of the Pyrenean basins, snowmelt contributes more to the discharge than rainfall in the spring. The analysis of data shows a decrease in winter precipitation in the last 50 years causing a decrease in both winter and spring discharges and introducing changes in the distribution of streamflow throughout the year. 相似文献
15.
Abstract An integrated model for the simulation and prediction of both snowmelt quantity and quality from seasonal snow cover in a mountain basin has been developed at the Institute of Hydrology and Hydraulics SAS in cooperation with the Geological Institute of Dionyz ?tur. The model will be used for both the simulation and forecast of snow accumulation and the accumulation of SO2- 4 washout. At the present time it is mostly used for simulation of the SO2- 4 concentration and water supply in snow. In this paper the results of SO2- 4 modelling in a brook are also presented. 相似文献
16.
Getnet Y. Muluye 《水文科学杂志》2013,58(7):1118-1128
Abstract There is a continuing effort to advance the skill of long-range hydrological forecasts to support water resources decision making. The present study investigates the potential of an extended Kalman filter approach to perform supervised training of a recurrent multilayer perceptron (RMLP) to forecast up to 12-month-ahead lake water levels and streamflows in Canada. The performance of the RMLP was compared with the conventional multilayer perceptron (MLP) using suites of diagnostic measures. The results of the forecasting experiment showed that the RMLP model was able to provide a robust modelling framework capable of describing complex dynamics of the hydrological processes, thereby yielding more accurate and realistic forecasts than the MLP model. The performance of the method in the present study is very promising; however, further investigation is required to ascertain the versatility of the approach in characterizing different water resources and environmental problems. Citation Muluye, G. Y. (2011) Improving long-range hydrological forecasts with extended Kalman filters. Hydrol. Sci. J. 56(7), 1118–1128. 相似文献
17.
Valentina Krysanova Fred Hattermann Shaochun Huang Cornelia Hesse Tobias Vetter Stefan Liersch 《水文科学杂志》2013,58(4):606-635
AbstractThe Soil and Water Integrated Model (SWIM) is a continuous-time semi-distributed ecohydrological model, integrating hydrological processes, vegetation, nutrients and erosion. It was developed for impact assessment at the river basin scale. SWIM is coupled to GIS and has modest data requirements. During the last decade SWIM was extensively tested in mesoscale and large catchments for hydrological processes (discharge, groundwater), nutrients, extreme events (floods and low flows), crop yield and erosion. Several modules were developed further (wetlands and snow dynamics) or introduced (glaciers, reservoirs). After validation, SWIM can be applied for impact assessment. Four exemplary studies are presented here, and several questions important to the impact modelling community are discussed. For which processes and areas can the model be used? Where are the limits in model application? How to apply the model in data-poor situations or in ungauged basins? How to use the model in basins subject to strong anthropogenic pressure?
Editor D. Koutsoyiannis; Associate editor C. Perrin 相似文献
18.
O. S. R. U. BHANU KUMAR 《水文科学杂志》2013,58(5):515-525
Abstract This paper presents the relationship between Indian summer monsoon total rainfall and two parameters from Eurasian snow cover, one being the winter snow cover extent and the other the area of spring snowmelt. Satellite-derived Eurasian snow cover extent and Indian monsoon rainfall data were obtained from the NOAA/NESDIS and the India Meteorological Department (IMD) for the period 1966–1985. Seasonal cyclic variations of snow cover showed a higher swing in both the winter and the spring seasons of the cycle as compared to the remaining seasons of the year in the lower region of the cycle. The established inverse relation between winter snow cover and monsoon rainfall during June to September is further extended. Winter snow cover is very strongly correlated with spring snowmelt over Eurasia. Spring snowmelt area is obtained by subtracting the May snow cover extent from that of the previous February. The variations of spring snowmelt were also compared with Indian total monsoon rainfall. The detected correlation is stronger between snowmelt and monsoon rainfall than between the winter snow cover and the monsoon rainfall. There is also a significant multiple correlation among winter snow cover, spring snowmelt and monsoon rainfall. Lastly, a significant multiple correlation suggested a multiple regression equation which might improve the climatic prediction of monsoon rainfall over India. 相似文献
19.
AbstractReservoir operation is studied for the Daule Peripa and Baba system in Ecuador, where El Niño events cause anomalously heavy precipitation. Reservoir inflow is modelled by a Markov-switching model using El Niño–Southern Oscillation (ENSO) indices as input. Inflow is forecast using 9-month lead time ENSO forecasts. Monthly reservoir releases are optimized with a genetic algorithm, maximizing hydropower production during the forecast period and minimizing deviations from storage targets. The method is applied to the existing Daule Peripa Reservoir and to a planned system including the Baba Reservoir. Optimized operation is compared to historical management of Daule Peripa. Hypothetical management scenarios are used as the benchmark for the planned system, for which no operation policy is known. Upper bounds for operational performance are found via dynamic programming by assuming perfect knowledge of future inflow. The results highlight the advantages of combining inflow forecasts and storage targets in reservoir operation.
Editor D. Koutsoyiannis; Associate editor I. Nalbantis 相似文献
20.
Serdar Surer 《水文科学杂志》2013,58(8):1684-1694
Abstract Monitoring snow parameters (e.g. snow-cover area, snow water equivalent) is challenging work. Because of its natural physical properties, snow strongly affects the evolution of weather on a daily basis and climate on a longer time scale. In this paper, the snow recognition product generated from the MSG-SEVIRI images within the framework of the Hydrological Satellite Facility (HSAF) Project of EUMETSAT is presented. Validation of the snow recognition product H10 was done for the snow season (from 1 January to 31 March) of the water year 2009. The MOD10A1 and MOD10C2 snow products were also used in the validation studies. Ground truth of the products was obtained by using 1890 snow depth observations from 20 meteorological stations, which are mainly located in mountainous areas and are distributed across the eastern part of Turkey. The possibility of 37% cloud cover reduction was obtained by merging 15-min observations from MSG-SEVIRI as opposed to using only one daily observation from MODIS. The coarse spatial resolution of the H10 product gave higher commission errors compared to the MOD10A1 product. Snow depletion curves obtained from the HSAF snow recognition product were compared with those derived from the MODIS 8-day snow cover product. The preliminary results show that the HSAF snow recognition product, taking advantage of using high temporal frequency measurement with spectral information required for snow mapping, significantly improves the mapping of regional snow-cover extent over mountainous areas. Citation Surer, S. and Akyurek, Z., 2012. Evaluating the utility of the EUMETSAT HSAF snow recognition product over mountainous areas of eastern Turkey. Hydrological Sciences Journal, 57 (8), 1–11. 相似文献