首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Rainfall simulators can be a useful research tool for some purposes but are quite unsuitable for others. They have been useful in soil erosion and infiltration studies for over eight decades, but the possibility of using a rainfall simulator in urban nonpoint source pollution involving urban non-erodible surfaces has not been fully explored. In this review, the versatility of different rainfall simulators of varying sizes, configurations and styles used in the past two decades are appraised for possible adaptation to urban sealed surfaces. Recommended criteria for detailed rainfall simulator reporting are also outlined.
EDITOR M.C. Acreman

ASSOCIATE EDITOR not assigned  相似文献   

2.
3.
Abstract

by Ghislain de Marsily, Academic Press, vii+440 pp. U.S. $29.95 (ISBN 0-12-208916-2) 1986.  相似文献   

4.
We report on numerical experiments to test the sensitivity of Lagrangian coherent structures (LCSs), found by identifying ridges of the finite-time Lyapunov exponent (FTLE), to errors in two systems representing the California Current System (CCS). First, we consider a synthetic mesoscale eddy field generated from Fourier filtering satellite altimetry observations of the CCS. Second, we consider the full observational satellite altimetry field in the same region. LCS are found to be relatively insensitive to both sparse spatial and temporal resolution and to the velocity field interpolation method. Strongly attracting and repelling LCS are robust to perturbations of the velocity field of over 20% of the maximum regional velocity. Contours of the Okubo–Weiss (OW) parameter are found to be consistent with LCS in large mature eddies in the unperturbed systems. The OW parameter is unable to identify eddies at the uncertainty level expected for altimetry observations of the CCS. At this expected error level, the FTLE method is reliable for locating boundaries of large eddies and strong jets. Small LCS features such as lobes are not well resolved even at low error levels, suggesting that reliable determination of lobe dynamics from altimetry will be problematic.  相似文献   

5.
Abstract

By J. Kleczek. D. Reidel Publishing Company, xxiii+339 pp., us$ 64 (ISBN 90-277-2409-1), Paperback Edition US$19.50 (ISBN 90-277-2423-7).  相似文献   

6.
7.
Abstract

By P. H. Roberts and A. M. Soward (Editors). Academic Press Inc. (London) Ltd, $36.25 (£17.50). (ISBN 0 12 589650 6.)  相似文献   

8.
Current crustal movement in Chinese mainland   总被引:2,自引:0,他引:2  
The quantification of tectonic deformation in the Eastern and Central Asia is of great significance for the study on global plate motion and lithospheric dynamics. In the past four years, the velocity field of horizontal crustal movement for the Chinese mainland has been established for the first time thanks to the intensified GPS measure-ments and its improved accuracy. The velocity field derived from GPS measurements delineates the patterns of tectonic deformation in the Chinese mainland in the unprecedented detail, and thus reveals the new features of the ongoing tectonic process resulted from the collision of Indian plate to Eurasian plate. Meanwhile, the surface offset induced by two strong earthquakes occurred in Chinese mainland was sampled precisely using InSAR technique.  相似文献   

9.
Abstract

Edited By J. Christensen-Dalsgaard and S. Frandsen. D. Reidel, xxi + 604 pp., Hardb. Dfl. 230.00, us$ 109.00 (ISBN 90-277-2614-0), Paperb. Dfl. 95.00 US$ 49.00 (ISBN 90-277-2615-9).  相似文献   

10.
The multivariate Gaussian random function model is commonly used in stochastic hydrogeology to model spatial variability of log-conductivity. The multi-Gaussian model is attractive because it is fully characterized by an expected value and a covariance function or matrix, hence its mathematical simplicity and easy inference. Field data may support a Gaussian univariate distribution for log hydraulic conductivity, but, in general, there are not enough field data to support a multi-Gaussian distribution. A univariate Gaussian distribution does not imply a multi-Gaussian model. In fact, many multivariate models can share the same Gaussian histogram and covariance function, yet differ by their patterns of spatial continuity at different threshold values. Hence the decision to use a multi-Gaussian model to represent the uncertainty associated with the spatial heterogeneity of log-conductivity is not databased. Of greatest concern is the fact that a multi-Gaussian model implies the minimal spatial correlation of extreme values, a feature critical for mass transport and a feature that may be in contradiction with some geological settings, e.g. channeling. The possibility for high conductivity values to be spatially correlated should not be discarded by adopting a congenial model just because data shortage prevents refuting it. In this study, three alternatives to a multi-Gaussian model, all sharing the same Gaussian histogram and the same covariance function, but with different continuity patterns for extreme values, were considered to model the spatial variability of log-conductivity. The three alternative models, plus the traditional multi-Gaussian model, are used to perform Monte Carlo analyses of groundwater travel times from a hypothetical nuclear repository to the ground surface through a synthetic formation similar to the Finnsjön site in Sweden. The results show that the groundwater travel times predicted by the multi-Gaussian model could be ten times slower than those predicted by the other models. The probabilities of very short travel times could be severely underestimated using the multi-Gaussian model. Consequently, if field measured data are not sufficient to determine the higher-order moments necessary to validate the multi-Gaussian model — which is the usual situation in practice — other alternative models to the multi-Gaussian one ought to be considered.  相似文献   

11.
12.
Lack of basic sanitation systems threaten environmental and human health in low income urban communities. In 2005, the Government of Zimbabwe carried out a cleanup exercise in urban areas involving the destruction of illegal structures which left many people homeless. As a solution to this problem, the government embarked on an extensive housing construction exercise on unserviced land; the ‘Garikai/Hlalani Kuhle’ development programme. The objective of this paper was to investigate the sanitation status in one such area (Cowdray Park Extension, Bulawayo) and determine a sustainable sanitation system for the improved collection of wastewater from the unserviced low income urban area. The study was carried out between October 2010 and February 2011. The sanitation status as well as the residents’ preferences for improved sanitation and the economic set up of the community for the study area was determined through use of questionnaires to the residents. The local authority was then consulted to recommend sanitation facilities and system for the area that met regulatory requirements. A literature study identified sanitation options that were applicable to low income and high density urban areas. The baseline survey found that 61% of the people in the study area lacked sanitation facilities and practiced open defecation. The majority of the residents (70%) preferred ‘flush and discharge’ system sanitation facilities, which was in line with the local council’s requirements. On-site sanitation options were found not to be feasible as per the council regulations and the findings of the literature study, for areas with a high density of houses. Therefore a sewerage system was designed using the conventional sewerage design approach as well as the simplified sewerage design approach in order to determine the collection system that would best meet the needs of the community. In conclusion, the community was in dire need of a sanitation system and a waterborne offsite sanitation system was found to be a feasible option. The simplified sewerage system was found to deliver the same hydraulic benefits for collecting wastewater as the conventional but was 33% cheaper to construct and hence more affordable for the community. It was recommended that stringent environmental monitoring of the sanitation system be put in place to minimise any potential environmental impacts.  相似文献   

13.
AresearchonthegeothermalstructureinYanqing┐HuailaiBasinanditsneighbouringregionJIN-HUAZU(祖金华)QIAN-FANWU(吴乾蕃)YU-FANGLIAN(廉雨方)...  相似文献   

14.
A review of ionospheric currents,the external part of geomagnetic solar quiet (Sq)variation and the internal part of the induced currentwithin the Earth, has been carried out.The theoretical background has been reviewed,and the method of analysis, specificallythe spherical harmonic analysis (SHA),is presented. Various works are reviewed andfully discussed. It has been noted that anew model of the Sq current system could beused to obtain a mantle electrical conductivityprofile for hemispheres. It is suggested thatfurther research work be carriedout in other hemispheres using similarmodels for more robust interpretations.  相似文献   

15.
In this paper,the regional geologic setting and seismic hazard of Brunei Darussalam are outlined.The earthquake monitoring system and to ability to recored,process and analyze seismic events in surrounding areas are described,and some results of epicenter determinations by the monitoring system are given(Appendices I and Ⅱ)。  相似文献   

16.
Abstract

Edited by Barry Saltzman. Academic Press Inc. (London) Ltd., 1979. 432 pp. (527.20) (ISBN 0 12018821 X).  相似文献   

17.
Abstract

edited by R. M. Bonnet and A. K. Dupree. D. Reidel Publishing Company (1981), 584 pp. Dfl. 135/US$69.50. (ISBN 90 277 1275 1)  相似文献   

18.
Lectures given at the CNRS Summer School on Solar Astrophysics, Oleron, France, 25-29 May 1998, edited by P.-P. Rozelot, L. Klein and J.-C. Vial, Lecture Notes in Physics: Vol. 553, Springer-Verlag Berlin Heidelberg New York, 2000. VIII+214 pp., DM 104.00, hardbound (ISBN 3-540-67595-7)  相似文献   

19.
Abstract

by M. T. Landahl and E. Mollo-Christensen, Cambridge University Press, vi+154 pp., ?34.50 (ISBN (0-521-26306-9) 1986.  相似文献   

20.
A decade of Predictions in Ungauged Basins (PUB)—a review   总被引:2,自引:0,他引:2  
Abstract

The Prediction in Ungauged Basins (PUB) initiative of the International Association of Hydrological Sciences (IAHS), launched in 2003 and concluded by the PUB Symposium 2012 held in Delft (23–25 October 2012), set out to shift the scientific culture of hydrology towards improved scientific understanding of hydrological processes, as well as associated uncertainties and the development of models with increasing realism and predictive power. This paper reviews the work that has been done under the six science themes of the PUB Decade and outlines the challenges ahead for the hydrological sciences community.

Editor D. Koutsoyiannis

Citation Hrachowitz, M., Savenije, H.H.G., Blöschl, G., McDonnell, J.J., Sivapalan, M., Pomeroy, J.W., Arheimer, B., Blume, T., Clark, M.P., Ehret, U., Fenicia, F., Freer, J.E., Gelfan, A., Gupta, H.V., Hughes, D.A., Hut, R.W., Montanari, A., Pande, S., Tetzlaff, D., Troch, P.A., Uhlenbrook, S., Wagener, T., Winsemius, H.C., Woods, R.A., Zehe, E., and Cudennec, C., 2013. A decade of Predictions in Ungauged Basins (PUB)—a review. Hydrological Sciences Journal, 58 (6), 1198–1255.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号