Hydrological modelling of the Chaohe Basin in China: Statistical model formulation and Bayesian inference   总被引：4，自引：0，他引：4  

Jing Yang  Peter Reichert  Karim C. Abbaspour  Hong Yang 《Journal of Hydrology》2007,340(3-4):167-182

Calibration of hydrologic models is very difficult because of measurement errors in input and response, errors in model structure, and the large number of non-identifiable parameters of distributed models. The difficulties even increase in arid regions with high seasonal variation of precipitation, where the modelled residuals often exhibit high heteroscedasticity and autocorrelation. On the other hand, support of water management by hydrologic models is important in arid regions, particularly if there is increasing water demand due to urbanization. The use and assessment of model results for this purpose require a careful calibration and uncertainty analysis. Extending earlier work in this field, we developed a procedure to overcome (i) the problem of non-identifiability of distributed parameters by introducing aggregate parameters and using Bayesian inference, (ii) the problem of heteroscedasticity of errors by combining a Box–Cox transformation of results and data with seasonally dependent error variances, (iii) the problems of autocorrelated errors, missing data and outlier omission with a continuous-time autoregressive error model, and (iv) the problem of the seasonal variation of error correlations with seasonally dependent characteristic correlation times. The technique was tested with the calibration of the hydrologic sub-model of the Soil and Water Assessment Tool (SWAT) in the Chaohe Basin in North China. The results demonstrated the good performance of this approach to uncertainty analysis, particularly with respect to the fulfilment of statistical assumptions of the error model. A comparison with an independent error model and with error models that only considered a subset of the suggested techniques clearly showed the superiority of the approach based on all the features (i)–(iv) mentioned above.  相似文献   

Interstellar proteins and the discovery of a new absorption feature at λ=2800 Å     

L. M. Karim  F. Hoyle  N. C. Wickramasinghe 《Astrophysics and Space Science》1983,94(1):223-229

The discovery of a broad interstellar absorption feature centred on λ2800 Å in the extinction curve of starlight confirms the presence of proteinaceous material in grains.  相似文献   

Development of analytical seismic fragility functions for the common buildings in Iran     

Karim Zadeh  Zarin  Ghafory-Ashtiany  Mohsen  Kalantari  Afshin  Shokuhirad  Sahar 《Bulletin of Earthquake Engineering》2022,20(11):5905-5942

Bulletin of Earthquake Engineering - One of the main components for developing regional seismic risk models is the fragility functions of common building types. Due to the differences between the...  相似文献   

A coupled numerical model for simulation of wave breaking and hydraulic performances of a composite seawall     

Mohammed Fazlul Karim  Tawatchai Tingsanchali   《Ocean Engineering》2006,33(5-6):773-787

A numerical model is developed by combining a porous flow model and a two-phase flow model to simulate wave transformation in porous structure and hydraulic performances of a composite type low-crest seawall. The structure consists of a wide submerged reef, a porous terrace at the top and an impermeable rear wall. The porous flow model is based on the extended Navier-Stokes equations for wave motion in porous media and k−ε turbulence equations. The two-phase flow model combines the water domain with the air zone of finite thickness above water surface. A unique solution domain is established by satisfying kinematic boundary condition at the interface of air and water. The free surface advection of water wave is modeled by the volume of fluid method with newly developed fluid advection algorithm. Comparison of computed and measured wave properties shows reasonably good agreement. The influence of terrace width and structure porosity is investigated based on numerical results. It is concluded that there exist optimum value of terrace width and porosity that can maximize hydraulic performances. The velocity distributions inside and in front of the structure are also investigated.  相似文献   

Simulating the effects of land use changes on soil erosion using RUSLE model   总被引：3，自引：0，他引：3  

Ataollah Kavian  Samaneh Hoseinpoor Sabet  Karim Solaimani  Behnoosh Jafari 《国际地球制图》2017,32(1):97-111

The aim of this paper is to evaluate the impacts of land use change on soil loss. Soil loss was quantified using the revised universal soil loss equation model in Darabkola catchment. Land use maps of 1992, 1998 and 2012 were derived from Landsat Thematic Mapper data. The mean annual soil loss was therefore determined for these years. The results showed open-canopy forest area decreased by 36% between 1992 and 1998. Likewise, the decreasing trend of forest lands which are near to residential areas has continued from 1795 ha in 1998 to 1765 ha in 2012. Also the results indicate that the maximum annual soil loss ranged from 5.06, 6.19 and 15.23 ton h^?1 y^?1 in 1992, 1998 and 2012, respectively. Also, by assuming that all watershed conditions and land uses be constant in the future, then the area of close- and open-canopy forest and dry agricultural lands will be 23.23, 2.88 and 29.89 ha in 2040, respectively.  相似文献   

Monitoring of selected pharmaceuticals over 3 years in a detrital aquifer during artificial groundwater recharge     

Lucila Candela  Karim Tamoh  Iñaki Vadillo  Javier Valdes-Abellan 《Environmental Earth Sciences》2016,75(3):244

  相似文献   

Weathering processes in the Indus River Basin: implications from riverine carbon, sulfur, oxygen, and strontium isotopes   总被引：2，自引：0，他引：2  

Ajaz Karim  Jan Veizer   《Chemical Geology》2000,170(1-4):153-177

This study deals with the major ions and isotope systematics for C, O, S, and Sr in the Indus River Basin (IRB). Major ion chemistry of the Indus, and most of its headwater tributaries, follow the order Ca²⁺>Mg²⁺>(Na⁺+K⁺) and HCO₃⁻>(SO₄²⁻+Cl⁻)>Si. In the lowland tributaries and in some of the Punjab rivers, however, (Na⁺+K⁺) and (SO₄²⁻+Cl⁻) predominate. Cyclic salts, important locally for Na⁺ in dilute headwater tributaries, constitute about 5% of the annual solutes transported by the Indus. Weathering of two lithologies, sedimentary carbonates and crystalline rocks, controls the dissolved inorganic carbon (DIC) concentrations and its carbon isotope systematics throughout the Indus, but turbulent flow and lower temperatures in the headwaters, and storage in reservoirs in the middle and lower Indus promote some equlibration with atmospheric carbon dioxide. Combined evidence from sulfur and oxygen isotopic composition of sulfates refutes the proposition that dissolution of these minerals plays a significant role in the IRB hydrochemistry and suggests that any dissolved sulfates were derived by oxidation of sulfide minerals.

In the upper Indus, silicate weathering contributes as much as 75% (or even higher in some tributaries) of the total Na⁺ and K⁺, declining to less than 40% as the Indus exits the orogen. In contrast, about two-thirds of Ca²⁺ and Mg²⁺ in the upper Indus (over 70% in some tributaries) and three-fourth in the lower Indus, are derived from sedimentary carbonates. The ⁸⁷Sr/⁸⁶Sr ratios tend to rise with increasing proportions of silicate derived cations in the headwater tributaries and in the upper and middle Indus, but are out of phase or reversed in the lower Indus. Finally, close to the river mouth, the discharge weighted average contribution of silicate derived Ca²⁺+Mg²⁺ and silicate derived Na⁺+K⁺ are, respectively, about one-fourth and two-thirds of their total concentrations.  相似文献   

Optimization of water allocation in the Shatt al-Arab River under different salinity regimes and tide impact     

Ali D. Abdullah  Mario Erik Castro-Gama  Ioana Popescu  Pieter van der Zaag  Usama Karim  Qusay Al Suhail 《水文科学杂志》2018,63(4):646-656

Wastewater effluents from irrigation and the domestic and industrial sectors have serious impacts in deteriorating water quality in many rivers, particularly in areas under tidal influence. There is a need to develop an approach that considers the impact of human and natural causes of salinization. This study uses a multi-objective optimization–simulation model to investigate and describe the interactions of such impacts in the Shatt al-Arab River, Iraq. The developed model is able to reproduce the salinity distribution in the river given varying conditions. The salinity regime in the river varies according to different hydrological conditions and anthropogenic activities. Due to tidal effects, salinity caused by drainage water is seen to intrude further upstream into the river. The applied approach provides a way to obtain optimal solutions where both river salinity and deficit in water supply can be minimized. The approach is used for exploring the trade-off between these two objectives.  相似文献   

Joint frequency analysis and uncertainty estimation of coupled rainfall–runoff series relying on historical and simulated data     

Esmaeel Dodangeh  Karim Solaimani 《水文科学杂志》2020,65(3):455-469

ABSTRACT

Joint frequency analysis and quantile estimation of extreme rainfall and runoff (ERR) are crucial for hydrological engineering designs. The joint quantile estimation of the historical ERR events is subject to uncertainty due to the errors that exist with flow height measurements. This study is motivated by the interest in introducing the advantages of using Hydrologic Simulation Program-Fortran (HSPF) simulations to reduce the uncertainties of the joint ERR quantile estimations in Taleghan watershed. Bivariate ERR quantile estimation was first applied on P_AMS-Q_SIM pairs and the results were compared against the historical rainfall–runoff data (P_AMS-Q_obs). Student’s t and Frank copulas with respectively Gaussian-P3 and Gaussian-LN3 marginal distributions well suited to fit the P_AMS-Q_obs and P_AMS-Q_SIM pairs. Results revealed that confidence regions (CRs) around the p levels become wider for P_AMS-Q_obs compared to P_AMS-Q_SIM, indicating the lower sampling uncertainties of HSPF simulations compared to the historical observations for bivariate ERR frequency analysis.  相似文献   

基于Ecopath模型的孟加拉国孟加拉湾海域营养结构和能量流动分析     

Karim Ehsanul  刘群  薛莹  Hasan Shanur Jahedul  Hoq M Enamul  Mahmud Yahia 《海洋学报(英文版)》2019,38(10):27-42

依据现有研究提供的信息，在孟加拉国孟加拉湾（BoB）新划定的超过90 000 km²的海域基于Ecopath方法利用2016年7月至2017年6月的数据构建了该生态系统的营养通道模型。对食物网中营养级从1（主要生产者和碎屑）到3.45（鲨鱼）的各功能群之间的营养相互作用进行评估，所研究的共19个功能群被认为代表了其中所有的营养级。大多数消费者的生态营养转换效率（EE）超过0.80；表明这是一个被高度利用的生态系统，并且从低营养级到高营养级有较高的能量转换效率。此外，整个生态系统的净效率（0.0018）和能量转换效率（11.12%）标志着当前这一"正在发展中的生态系统"已趋向成熟。生态系统的冗余度（64.6）和聚合度（35.4）也表明了这一生态系统的稳定性。因此，本研究认为这一海域具有显著的后备力量面对压力情况并有能力快速恢复到初始状态。  相似文献