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1.
S. E. JØRGENSEN 《水文科学杂志》2013,58(2):143-149
Abstract On a regional scale (from about 10 to 105km2) estimations of actual evapotranspiration ET for water balance equations are generally missing. The various methods available at present are briefly described and discussed. The use of remote sensing, in particular infra-red thermometry by satellite, in conjunction with soil energy budget data, is the only method to provide satisfactory data on the same scale in space and lime for water balance models. This method is being studied at the INRA Bioclimatology Station at Avignon in the framework of the European ‘Tellus’ project for using HCMM satellite data. Systems for continuously recording the components of the energy budget and ET have been installed in the Crau plain, north of Marseilles, in both a dry area and a large area of irrigated pastures. By combining the recorded measurements with the satellite data and starting from values for elements of 25 ha (500 m × 500 m), the ET for the whole of the Crau plain can be estimated. First results are analysed and the possibilities and limitations of the method are discussed. 相似文献
2.
Event-based estimation of water budget components using a network of multi-sensor capacitance probes
Andrey Guber 《水文科学杂志》2013,58(7):1227-1241
Abstract A new approach was developed for estimating vertical soil water fluxes using soil water content time series data. Instead of a traditional fixed time interval, this approach utilizes the time interval between two sequential minima of the soil water storage time series to identify groundwater recharge events and calculate components of the soil water budget. We calculated water budget components: surface-water excess (Sw), infiltration less evapotranspiration (I – ET) and groundwater recharge (R) from May 2001 to January 2003 at eight locations at the USDA Agricultural Research Center, Beltsville, Maryland, USA. High uncertainty was observed for all budget components. This uncertainty was attributed to spatial and temporal variation in Sw, I – ET and R, and was caused by nonuniform rainfall distributions during recharge events, variability in the profile water content, and spatial variability in soil hydraulic properties. The proposed event-based approach allows estimating water budget components when profile water content monitoring data are available. Citation Guber, A., Gish, T., Pachepsky, Y., McKee, L., Nicholson, T. & Cady, R. (2011) Event-based estimation of water budget components using a network of multi-sensor capacitance probes. Hydrol. Sci. J. 56(7), 1227–1241. 相似文献
3.
ABSTRACTEstimating groundwater recharge is crucial to ensuring the proper management of aquifers. In this study, net regional recharge and spatial potential recharge are estimated at four watersheds within the Charlevoix–Haute-Côte-Nord (CHCN) regions, Quebec Province, Canada. Four methods are applied based on available data. The first two approaches are regional water budget methods. These two methods differ in their estimation of vertical inflow (VI), which is estimated from two hydrological models: GR4J and HYDROTEL. The third method estimates potential recharge spatially over the study area. Finally, the streamflow data are analysed using the Eckhardt baseflow separation method to obtain an estimation of recharge, assuming that discharge is equal to recharge. According to the results of all investigated methods, the mean annual recharge for the CHCN region is approximately 183 mm, which is 18% of the total annual precipitation (P). The discussion section highlights uncertainties due to the assumptions of each method and the reliability of the data. 相似文献
4.
完备震级是评估区域地震台网检测能力的一个定量指标,本文采用能反映区域地震台网检测能力的时空分布细节特征的概率完备震级分析方法,对首都圈地震台网的检测能力进行了研究,通过对首都圈2002-2009共8年的地震目录和台站资料的分析处理,得到了首都圈地震台网的完备震级时空分布,据此对台网的检测能力进行了评估,并结合模拟结果探讨了提升台网检测能力的可能性.结果表明：首都圈地震台网的整体检测能力较强,北京地区的检测能力尤其突出,但部分区域检测能力仍有一定的提升空间;模拟结果表明,在东北、西北、西南等位置增加台站可能有助于进一步提高台网的检测能力.相关研究结果可能对未来首都圈地震台网的优化具有参考意义. 相似文献
5.
Based on the first P wave arrival time data of local earthquakes recorded in the Kunming Telemetry Seismic Network in 1982–1989,
the P travel time corrections of the stations in the network were obtained by use of the parameter separation method and the
multiple event location method. This set of the corrections reflects the feature of lateral inhomogeneous structure of the
upper crust beneath the network to certain degree. The geographic distribution of the sation corrections has obviously regional
characteristics, by which the studied area is divided into three sub-areas. In the Western Yunnan area where the stations
are the most dense, except the stations of Yunxian, Shidian and Wanding in south, the station corrections are not greater
than 0.15 sec. In the eastern area (to the east of Chuxiong) where the network has slightly wider station interval, most of
them show obviously positive delay. In southern area, including stations of Wenshan, Simao, Jinghong, Yunxian, Shidian and
Wanding, all the stations have large negative delay. The results consist with the basic feature of geologic setting in Yunnan
area. The accuracy of the relocated hypocentral parameters based on the corrected travel time data has fairly improved. Therefore
the station corrections can be used to the routine processing of earthquake location in the Kunming Seismic Network.
The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,15, 136–145, 1993. 相似文献
6.
ABSTRACT Recently developed rainfall network design techniques are discussed and compared. Present day hydrological studies require high levels of accuracy from collected data. Also, scientists need to know the degree of accuracy of the information they use. The existing rainfall network in the Kizilirmak basin must be redesigned in order to meet the required level of accuracy preset by rainfall data users. The three following techniques were applied: optimum interpolation procedure which is a flexible method; variance of mean areal rainfall; and the analysis of variance. The existing network of 52 gauges is redesigned so that the network will have an average root mean square error (rmse) of ? 32 mm and the percentage of the area with rmse > 36 mm is limited to 10%. It is found that the proposed criteria are satisfied by a network of 53 gauges of which eight were newly established and seven of the existing ones removed. 相似文献
7.
High spatial and temporal resolution of precipitation data is critical input for hydrological budget estimation and flash flood modelling. This study evaluated four methods [Bias Adjustment (BA), Simple Kriging with varying Local Means (SKlm), Kriging with External Drift (KED), and Regression Kriging (RK)] for their performances in incorporating gauge rainfall measurements into Next Generation Weather Radar (NEXRAD) multi‐sensor precipitation estimator (MPE; hourly and 4 × 4 km2). Measurements from a network of 50 gauges at the Upper Guadalupe River Basin, central Texas and MPE data for the year 2004 were used in the study. We used three evaluation coefficients percentage bias (PB), coefficient of determination (R2), and Nash–Sutcliffe efficiency (NSE) to examine the performance of the four methods for preserving regional‐ and local‐scale characteristics of observed precipitation data. The results show that the two Kriging‐based methods (SKlm and RK) are in general better than BA and KED and that the PB and NSE criteria are better than the R2 criterion in assessing the performance of the four methods. It is also worth noting that the performance of one method at regional scale may be different from its performance at local scale. Critical evaluation of the performance of different methods at local or regional scale should be conducted according to the different purposes. The results obtained in this study are expected to contribute to the development of more accurate spatial rainfall products for hydrologic budget and flash flood modelling. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
8.
The paper introduces the horizontal crustal movement obtained from GPS observations in the regional networks (including the
basic network and the fiducial network) of the Crustal Movement Observation Network of China (CMONOC) carried out in 1999
and 2001. This paper is characterized by the acquisition of the horizontal displacement velocities during the period from
1999 to 2001 at the observation stations in the regional networks with datum definition of a group of stable stations with
small mutual displacements in east China. Based on the most detailed map of horizontal crustal movement in Chinese mainland,
the division of blocks, their displacements and deformations are studied. An approach to analysis of the intensity of the
horizontal crustal deformation is proposed. The general characteristics of the recent horizontal crustal movement in Chinese
mainland and that before the Kunlunshan earthquake of M=8.1 on November 14, 2001 are analyzed.
Foundation item: The National Development and Programming Project for Key Basic Research (95-13-03-07). 相似文献
9.
AbstractAvailable data from nearby gauging stations can provide a great source of hydrometric information that is potentially transferable to an ungauged site. Furthermore, streamflow measurements may even be available for the ungauged site. This paper explores the potential of four distance-based regionalization methods to simulate daily hydrographs at almost ungauged pollution-control sites. Two methods use only the hydrological information provided by neighbouring catchments; the other two are new regionalization methods parameterized with a limited number of streamflow data available at the site of interest. Based on a network of 149 streamgauges and 21 pollution-control sites located in the Upper Rhine-Meuse area, the comparative assessment demonstrates the benefit of making available point streamflow measurements at the location of interest for improving quantitative streamflow prediction. The advantage is moderate for the prediction of flow types (stormflow, recession flow, baseflow) and pulse shape (duration of rising limb and falling limb).
Editor Z.W. Kundzewicz; Associate editor A. Viglione 相似文献
10.
A Neural Network model has been developed for estimating the total electron content (TEC) of the ionosphere. TEC is proportional
to the delay suffered by electromagnetic signals crossing the ionosphere and is among the errors that impact GNSS (Global
Navigation Satellite Systems) observations. Ionospheric delay is particularly a problem for single frequency receivers, which
cannot eliminate the (first-order) ionospheric delay by combining observations at two frequencies. Single frequency users
rely on applying corrections based on prediction models or on regional models formed based on actual data collected by a network
of receivers. A regional model based on a neural network has been designed and tested using data sets collected by the Brazilian
GPS Network (RMBC) covering periods of low and high solar activity. Analysis of the results indicates that the model is capable
of recovering, on average, 85% of TEC values. 相似文献
11.
《水文科学杂志》2013,58(4):645-653
Abstract Examination of precipitation in the Tibetan Plateau is important to understanding the regional water cycle processes and the plateau-scale energy budget. Based on hourly precipitation data obtained during the GAME-Tibet intensive observation period at four sites, the spatial distribution of precipitation in summer 1998 within the Anduo area was examined. The results show that, between 1 July and 11 September 1998, the precipitation that occurred simultaneously (at the same hours) at the sites accounted for 6.9–15.3% of the total precipitation at each site during the study period. Even at the two observation sites that are only 20 km apart, the percentage of precipitation that occurred simultaneously was quite small. This indicates that precipitation occurred not only frequently but also very locally, except on several days with very strong monsoon precipitation. The limited observations highlight that the precipitation distribution is quite complex, and large-scale intensive precipitation observations are needed in the future to clarify the heterogeneity of precipitation on the Tibetan Plateau. 相似文献
12.
AbstractOne of the main challenges faced by hydrologists and water engineers is the estimation of variables needed for water resources planning and management in ungauged river basins. To this end, techniques for transposing information, such as hydrological regional analyses, are widely employed. A method is presented for regionalizing flow-duration curves (FDCs) in perennial, intermittent and ephemeral rivers, based on the extended Burr XII probability distribution. This distribution shows great flexibility to fit data, with accurate reproduction of flow extremes. The performance analysis showed that, in general, the regional models are able to synthesize FDCs in ungauged basins, with a few possible drawbacks in the application of the method to intermittent and ephemeral rivers. In addition to the regional models, we summarize the experience of using synthetic FDCs for the indirect calibration of the Rio Grande rainfall–runoff model parameters in ungauged basins.Editor D. KoutsoyiannisCitation Costa, V., Fernandes, W., and Naghettini, M., 2013. Regional models of flow-duration curves of perennial and intermittent streams and their use for calibrating the parameters of a rainfall–runoff model. Hydrological Sciences Journal, 59 (2), 262–277. 相似文献
13.
By use of the specialized under ground electrodes as the sensor, the Experimental Multi-station Network observed Seismic Electromagnetic
radiationsprior to the moderately strong earthquake. From the great number of electromagnetic anomalies recorded by the network continuously
for about 10 years, it can be sure that the anomalies are related to earthquakes aboveM
s 5 within 300 km. The stronger the magnitude of the earthquake is, the better the relation is. The abnormal electromagnetic
radiation information appears in a short-time before the moderately strong earthquake. The continuous automatic pen recording
shows that the electromagnetic information is the waveform of the paroxysmal wave group, and has the features of undulating
enhancement, amplitude in inversely proportion to epicentral distance, frequency increase, regional similarity of wave froms
and directivity, etc.. It also contains some quantitative elements related to the parameters of the earthquake. The above
characteristics and correlative elements can provide important bases for predicting the three elements of the earthquake.
The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,15, 83–90, 1993.
Associate Professor Da-Yuan CHANG and Teacher Feng CHEN have gave us a lot of help during the study. 相似文献
14.
ABSTRACT The purpose of an hydrometric network is to obtain data giving answers to problems raised by the use of water. The methodology suggested in this paper is essentially based on the regional identification of the actual and potential uses of water, on the estimate of the intensity of their use and on the determination of the hydrological characteristics related to this demand. The level of accuracy required for these characteristics is an important feature in the rationalization procedure. The various types of stations are defined according to the purpose of their use and the network considered is on a dynamic basis depending on the evolution of uses. The major results obtained for Quebec by the application of this method are described. 相似文献
15.
Krishna Bahadur KC 《水文科学杂志》2013,58(6):994-1014
Abstract This paper assesses strategic water availability and use under different development pathways on a basin scale using remote sensing (RS), geographical information systems (GIS) and a spatial water budget model (SWBM). The SWBM was applied to the Upper Ing Basin in northern Thailand to investigate the spatial and temporal variations in the location of streams and water yields from different parts of the basin. The base simulation was carried out for the years 1998–2007 using a DEM and actual land-use data at 100-m resolution. The simulated stream network was compared with topographic maps under different flow conditions, which were successfully represented. The 10-year average simulated river flow rate was 1300 L/s, but it more than doubled during periods of heavy rainfall and decreased below 600 L/s in dry seasons. The total length of the streams (based on flow threshold of 25 L/s) on a typical day in the dry season differed by a factor of approx. 1.5. Agricultural water needs and possible extraction were assessed and presented by dividing the basin into 10 different zones based on the stream network. The results show that there is the potential for harvesting significant quantities of water at different spatial gradients with no initial water supply for irrigation. Monthly water yields for each zone were computed; the results varied from less than 50% to over 137% of the per hectare water yield for the entire basin. This variation was due to differences in topography and land cover. The impact of land use and climate change on streamwater availability was also studied. The basin shows very different hydrological responses. The changes in average river flow relative to the base simulation were +27.6%,??32.1%, +94% and +52.9% under deforestation, changing land use from paddy field to orchard, bare soil and increased rainfall scenarios, respectively. Citation Bahadur KC, K. (2011) Assessing strategic water availability using remote sensing, GIS and a spatial water budget model: case study of the Upper Ing Basin, Thailand. Hydrol. Sci. J. 56(6), 994–1014. 相似文献
16.
ABSTRACT Groundwater level fluctuations are caused by spatial and temporal superposition of processes within and outside the aquifer system. Most of the subsurface processes are usually observed on a small scale. Upscaling to the regional scale, as required for future climate change scenarios, is difficult due to data scarcity and increasing complexity. In contrast to the limited availability of system characteristics, high-resolution data records of groundwater hydrographs are more generally available. Exploiting the information contained in these records should thus be a priority for analysis of the chronical lack of data describing groundwater system characteristics. This study analyses the applicability of 63 indices derived from daily hydrographs to quantify different dynamics of groundwater levels in unconfined gravel aquifers from three groundwater regions (Bavaria, Germany). Based on the results of two different skill tests, the study aids index selection for different dynamic components of groundwater hydrographs. 相似文献
17.
JAROMÍR NEbreveMEC 《水文科学杂志》2013,58(2):70-73
Abstract For needs of planning and design, data on rainfall duration-intensity-frequency relations are necessary. For this purpose, a network of recording raingages has to be designed. Czechoslovakia has a relatively very dense network with considerably lengthy records. Analysis of this network and particularly of parameters of a new formula for rain intensity-duration-frequency relation, abstracted from this network observations, show that in conditions of a mountainous terrain, no geographical pattern related to topographical characteristics can be evaluated to limit the density of the network. On the other hand, the use of adequate statistical procedure can reduce the necessary lenght of records for the evaluation of reliable data of low frequency, which permits a rational and economical design of permanent and non-permanent networks. 相似文献
18.
Abstract Regressions between concentrations of major inorganic constituents and either specific conductance or streamflow discharge characterize chemical-quality conditions at a sampling site or of an area and can be used to estimate streamflow chemical-quality composition over time and in space where information is lacking or deficient. In this manner, less costly water quality network operations may be achieved for a given programme, enabling available resources to be reallocated to the collection and analysis of data where information is deficient. The SYSLAB system is a sequential set of documented special-purpose computer programs for statistically and graphically analysing historical water-quality records and deriving relevant regression relationships based upon this analysis. These computer programs have been applied under a variety of hydrological conditions to characterize regional chemical-quality patterns across the United States and in Pakistan. Case-study results using the proposed methodology are presented for Nigeria, Japan, and Pakistan. 相似文献
19.
Vassilis Z. Antonopoulos Soultana K. Gianniou Athanasios V. Antonopoulos 《水文科学杂志》2013,58(14):2590-2599
ABSTRACTEvaporation is one of the most important components in the energy and water budgets of lakes and is a primary process of water loss from their surfaces. An artificial neural network (ANN) technique is used in this study to estimate daily evaporation from Lake Vegoritis in northern Greece and is compared with the classical empirical methods of Penman, Priestley-Taylor and the mass transfer method. Estimation of the evaporation over the lake is based on the energy budget method in combination with a mathematical model of water temperature distribution in the lake. Daily datasets of air temperature, relative humidity, wind velocity, sunshine hours and evaporation are used for training and testing of ANN models. Several input combinations and different ANN architectures are tested to detect the most suitable model for predicting lake evaporation. The best structure obtained for the ANN evaporation model is 4-4-1, with root mean square error (RMSE) from 0.69 to 1.35 mm d?1 and correlation coefficient from 0.79 to 0.92.
EDITOR M.C. AcremanASSOCIATE EDITOR not assigned 相似文献
20.
After Ms=6.5 Yao＇an earthquake on January 15, 2000, a large amount of aftershock waveforms were recorded by the Near Source Digital Seismic Network （NSSN） installed by Earthquake Administration of Yunnan Province in the aftershock region. It provides profuse data to systematically analyze the features of Yao＇an earthquake. The crustal anisotropy is realized by shear wave splitting propagating in the upper crust. Based on the accurate aftershock relocations, the shear wave splitting parameters are determined with the cross-correlation method, and the results of different stations and regions are discussed in this paper. These conclusions are obtained as follows： firstly, the average fast directions of aftershock region are controlled by the regional stress field and parallel to the maximum horizontal compressive stress direction; secondly, the average fast directions of disparate stations and regions are different and vary with the structural settings and regional stress fields; finally, delay time value is affected by all sorts of factors, which is affinitive with the shear wave propagating medium, especially. 相似文献