Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere最新文献_第6页

Statistical atmospheric downscaling of short-term extreme rainfall by neural networks 短期极端降雨的神经网络统计大气降尺度

Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere Pub Date : 2001-01-01 Epub Date: 2001-10-04 DOI: 10.1016/S1464-1909(01)00071-5

J. Olsson , C.B. Uvo , K. Jinno

{"title":"Statistical atmospheric downscaling of short-term extreme rainfall by neural networks","authors":"J. Olsson , C.B. Uvo , K. Jinno","doi":"10.1016/S1464-1909(01)00071-5","DOIUrl":"https://doi.org/10.1016/S1464-1909(01)00071-5","url":null,"abstract":"<div><p>Statistical atmospheric rainfall downscaling, that is, statistical estimation of local or regional rainfall on the basis of large-scale atmospheric circulation, has been advocated to make the output from global and regional climate models more accurate for a particular location or basin. Neural networks (NNs) have been used for such downscaling, but their application has proved problematic, mainly due to the numerous zero-values present in short-term rainfall time series. In the present study, using serially coupled NNs was tested as a way to improve performance. Mean 12-hour rainfall in the Chikugo River basin, Kyushu Island, Southern Japan, was downscaled from observations of precipitable water and zonal and meridional wind speed at 850 hPa, averaged over areas within which the temporal variation was found to be significantly correlated with basin rainfall. Basin rainfall was ranked into four categories: no-rain (0) and low (1), high (2) and extreme (3) intensity. A series of NN experiments showed that the best overall performance in terms of hit rates was achieved by a two-stage approach in which a first NN distinguished between no-rain (0) and rain (1–3), and a second NN distinguished between low, high, and extreme rainfalls. Using either a single NN to distinguish between all four categories or three NNs to successively detect extreme values proved inferior. The results demonstrate the need for an elaborate configuration when using NNs for short-term downscaling, and the importance of including physical considerations in the NN application.</p></div>","PeriodicalId":101025,"journal":{"name":"Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere","volume":"26 9","pages":"Pages 695-700"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1464-1909(01)00071-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"137441671","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Investigating trends of hydrochemical time series of small catchments by artificial neural networks 应用人工神经网络研究小流域水化学时间序列变化趋势

Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere Pub Date : 2001-01-01 Epub Date: 2002-04-16 DOI: 10.1016/S1464-1909(01)85007-3

G. Lischeid

{"title":"Investigating trends of hydrochemical time series of small catchments by artificial neural networks","authors":"G. Lischeid","doi":"10.1016/S1464-1909(01)85007-3","DOIUrl":"10.1016/S1464-1909(01)85007-3","url":null,"abstract":"<div><p>The short-term variation of discharge and solute concentration of the runoff of small catchments generally reflects the interplay of a variety of different processes. This makes the investigation of anthropogenic impacts on the catchment's runoff often rather difficult. On the other hand, short-term dynamics at the output boundary provide information about the system. This information can be used, in principle at least, to assess its long-term behaviour more precisely. In this paper examples of time series of sulphate and nitrate in the runoff of two small forested catchments are presented. To minimise the danger of over-parametrisation, the objective was to find a very simple empirical model to map a substantial portion of the observed variance (daily values). Here artificial neural networks were applied. They yield an efficiency of more than 0.7 for the solutes investigated, based on discharge depth and air temperature as input variables only. As a next step, the invariance of these relationships was investigated. In the case of sulphate, a significant trend is observed. However, it differs considerably for different subregions of the regression plane. Thus the neural network approach reveals a much more detailed insight into temporal shifts of the dynamics than an overall trend analysis.</p></div>","PeriodicalId":101025,"journal":{"name":"Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere","volume":"26 1","pages":"Pages 15-18"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1464-1909(01)85007-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75712190","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 14

Monitoring based time-prediction of rock falls: Three case-histories 基于时间预测的岩崩监测:三个历史案例

Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere Pub Date : 2001-01-01 DOI: 10.1016/S1464-1909(00)00234-3

J. Zvelebill, M. Moser

引用次数: 47

Towards integrated assessment of the implications of global change for water management - the Rhine experience 迈向综合评估全球变化对水管理的影响-莱茵河经验

Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere Pub Date : 2001-01-01 DOI: 10.1016/S1464-1909(01)00049-1

H. Middelkoop, J. Kwadijk

引用次数: 26

Assessment of land use change in the thames catchment and its effect on the flood regime of the river 泰晤士河集水区土地利用变化的评估及其对河流洪水状况的影响

Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere Pub Date : 2001-01-01 Epub Date: 2001-07-13 DOI: 10.1016/S1464-1909(01)00053-3

S. Crooks, H. Davies

引用次数: 73

Assessing the effects of land use changes on floods in the meuse and oder catchment 评估土地利用变化对默斯河流域洪水的影响

Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere Pub Date : 2001-01-01 Epub Date: 2001-07-13 DOI: 10.1016/S1464-1909(01)00054-5

A. De Roo, M. Odijk, G. Schmuck, E. Koster, A. Lucieer

{"title":"Assessing the effects of land use changes on floods in the meuse and oder catchment","authors":"A. De Roo, M. Odijk, G. Schmuck, E. Koster, A. Lucieer","doi":"10.1016/S1464-1909(01)00054-5","DOIUrl":"https://doi.org/10.1016/S1464-1909(01)00054-5","url":null,"abstract":"<div><p>Recently, dramatic flooding occurred in several regions of the world. To investigate the causes of the flooding and the influence of land use, soil characteristics and antecedent catchment moisture conditions, the distributed catchment model LISFLOOD has been developed. LISFLOOD simulates runoff in large river basins. Two transnational European river basins are used to test and validate the model: the Meuse catchment (France, Belgium, Germany and The Netherlands) and the Oder basin (The Czech Republic, Poland and Germany). In the Meuse and Oder catchment, land use change information over the past 200 years is processed at the moment. The LISFLOOD simulation model is used to simulate the effects of these land use changes on floods. Some influences of land use and vegetation on the water balance are clear, such as the changing vegetation cover (leaf area index) which will influence evapotranspiration. However, not so much is known about the influences of vegetation on soil properties, which influencesinfiltration, soil water redistribution, throughflow and groundwater recharge.</p></div>","PeriodicalId":101025,"journal":{"name":"Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere","volume":"26 7","pages":"Pages 593-599"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1464-1909(01)00054-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91635116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 147

Verification of GPCP-1DD global satellite precipitation products using MAP surface observations 基于MAP地表观测的gcp - 1dd全球卫星降水产品验证

Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere Pub Date : 2001-01-01 Epub Date: 2001-06-04 DOI: 10.1016/S1464-1909(01)00026-0

P. Skomorowski , F. Rubel , B. Rudolf

{"title":"Verification of GPCP-1DD global satellite precipitation products using MAP surface observations","authors":"P. Skomorowski , F. Rubel , B. Rudolf","doi":"10.1016/S1464-1909(01)00026-0","DOIUrl":"10.1016/S1464-1909(01)00026-0","url":null,"abstract":"<div><p>Daily satellite precipitation estimates have become available for the first time by the Global Precipitation Climatology Project. The experimental version of the GPCP-1DD product, recently launched and available from NASA, provides the research community with 1 degree daily precipitation fields exclusively computed from satellite measurements. These comprise IR estimates from geostationary satellites and SSM/I data in the tropics as well as TOVS data from polar orbiting satellites at higher latitudes. The purpose of the present study is to verify the TOVS based GPCP-1DD rain rates over Central Europe with the surface precipitation measured with the dense rain gauge network operated during <em>The Mesoscale Alpine Programme</em> (MAP). 3 100 high quality daily rain gauge measurements during June/July 1997 have been objectively analyzed on the grid of the GPCP-1DD products. Verification results are given here in terms of difference fields (mean error=−0.59 mm/day), correlation coefficients (mean monthly value =0.57) as well as accuracy scores (probability of detection=0.6, false alarm ratio=0.2) and skill scores (true skill statistics=0.36). These scores are slightly inferior than those known from NWP model verifications.</p></div>","PeriodicalId":101025,"journal":{"name":"Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere","volume":"26 5","pages":"Pages 403-409"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1464-1909(01)00026-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88737072","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 11

Application of a catchment water quality model for assessment and prediction of nitrogen budgets 集水区水质模型在氮收支评估和预测中的应用

Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere Pub Date : 2001-01-01 Epub Date: 2001-07-13 DOI: 10.1016/S1464-1909(01)00048-X

M. Eisele, R. Kiese, A. Krämer, C. Leibundgut

{"title":"Application of a catchment water quality model for assessment and prediction of nitrogen budgets","authors":"M. Eisele, R. Kiese, A. Krämer, C. Leibundgut","doi":"10.1016/S1464-1909(01)00048-X","DOIUrl":"https://doi.org/10.1016/S1464-1909(01)00048-X","url":null,"abstract":"<div><p>The objective of this study is the assessment of a catchment water quality model towards its suitability for simulation of solute transport and nitrogen budgets and application in river basin management. The conceptual semi-distributed water budget and water quality model NPSM (Non Point Source Model) was applied in the meso-scale Brugga catchment (39,9 km<sup>2</sup>) in southwest Germany. Spatial distribution was achieved by classifying sub-areas based on the concept of hydrological chemical response units (CHRUs).</p><p>Parameter values for the runoff and nitrogen simulation were estimated from catchment properties, previous experimental and modelling studies, regional field studies and literature. Optimization of the parameter values, calibration of the model and validation of the simulation was achieved using the runoff curve, concentrations of nitrate and natural tracers. Sensitivity analysis revealed that only a few parameters were important for the simulation of runoff and the dynamics of the nitrogen fluxes. The simulated nitrate concentrations were strongly controlled by the nitrogen input, the water movements and the nitrogen reactions in the different sub-areas. Due to the lack of data, the parameterization of the nitrogen contents and reactions in the soil remained uncertain.</p><p>As a result of this study NPSM proved to be applicable in a meso-scale catchment performing satisfactory results for the simulation of stream flow. However the short time dynamics of the measured nitrate could not be fitted by the nitrogen simulation. An improvement of the short time performance can only be achieved using a more detailed soil and agricultural data basis. To evaluate the suitability of the model as a tool for river basin management, simulations for longer time periods and with additional nutrients have to be performed.</p></div>","PeriodicalId":101025,"journal":{"name":"Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere","volume":"26 7","pages":"Pages 547-551"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1464-1909(01)00048-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91605975","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 13

Density-dependent groundwater movement in sediments overlying salt domes - the Gorleben site example 盐丘上沉积物中依赖密度的地下水运动——戈莱本遗址的例子

Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere Pub Date : 2001-01-01 Epub Date: 2001-04-24 DOI: 10.1016/S1464-1909(01)00019-3

K. Schelkes, P. Vogel, H. Klinge

引用次数: 4

Simulation modeling at different scales to evaluate the productivity of water 在不同尺度上模拟建模以评价水的生产力

Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere Pub Date : 2001-01-01 Epub Date: 2002-01-11 DOI: 10.1016/S1464-1909(01)00100-9

P. Droogers, G. Kite

{"title":"Simulation modeling at different scales to evaluate the productivity of water","authors":"P. Droogers, G. Kite","doi":"10.1016/S1464-1909(01)00100-9","DOIUrl":"10.1016/S1464-1909(01)00100-9","url":null,"abstract":"<div><p>With the increasing scarcity of water and the need for real water saving measures, a clear understanding of the productivity of water is essential. For a basin in western Turkey, simulation modeling was performed at three different scales (field, irrigation scheme, and basin level) to obtain all terms of the water balance. These water balances were used to calculate the Productivity of Water (PW) at the three levels. Four PW indices were considered: PW<sub>irrigated</sub> (yield / irrigation), PW<sub>inflow</sub> (yield / net inflow), PW<sub>depleted</sub> (yield / depletion), and PW<sub>process</sub> (yield / process depletion), all expressed in kg yield per m<sup>3</sup> water. Two cotton fields were considered at the field scale and it was found that the more upstream field performed better than the field at the tail-end since runoff from the upstream field was used by downstream users and was not considered as a loss. At the irrigation scheme level PW<sub>irrigated</sub> was higher than at the individual cotton field level, since non-irrigated crops were also included. Other PW values were lower as crops more sensitive to drought were also found in the irrigated areas. Basin scale PWs were lower than those at the irrigation scheme, as large areas of the basin were covered with less productive land types. This study demonstrates that the PW indices provide quantitative measures of water dynamics. Models provide a useful methodology for extending field observation for the estimation of the indicators.</p></div>","PeriodicalId":101025,"journal":{"name":"Physics and Chemistry of the Earth, Part B: Hydrology, Oceans and Atmosphere","volume":"26 11","pages":"Pages 877-880"},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1464-1909(01)00100-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89313328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 25