Time filter

Source Type

Wang D.W.,Beijing Normal University | Wang D.W.,Haihe River Water Conservancy Commission | Wang J.D.,Beijing Normal University | Liang S.L.,University of Maryland University College
Science China Earth Sciences | Year: 2010

Leaf area index (LAI) is an important parameter in monitoring crop growth. One of the methods for retrieving LAI from remotely sensed observations is through inversion of canopy reflectance models. Many model inversion methods fail to account for variable LAI values at different crop growth stages. In this research, we use the crop growth model to describe the LAI changes with crop growth, and consider a priori LAI values at different crop growth stages as constraint information. The key approach of this research is to assimilate multiple canopy reflectance values observed at different growth stages and a priori LAI values into a coupled crop growth and radiative transfer model sequentially using a variational data assimilation algorithm. Adjoint method is used to minimize the cost function. Any other information source can be easily incorporated into the inversion cost function. The validation results show that the time series of MODIS canopy reflectance can greatly reduce the uncertainty of the inverted LAI values. Compared with MODIS LAI product at Changping and Shunyi Counties of Beijing, this method has significantly improved the estimated LAI temporal profile. © 2010 Science China Press and Springer-Verlag Berlin Heidelberg.

Yu R.,Hohai University | Wang H.-M.,Hohai University | Niu W.-J.,Hohai University | Niu F.,Hohai University | Niu F.,Haihe River Water Conservancy Commission
Xitong Gongcheng Lilun yu Shijian/System Engineering Theory and Practice | Year: 2013

The management policy taken by government could have some influence on the activity of subjects in water resource conflict. Taking this into account will provide some reference for the solution of water resource conflict in the Zhanghe River Basin. In view of this, cellular automata method is used to describe the activity of group members and the process of water recourse conflict is simulated. Meanwhile, based on the social attribute of human beings and group environment, i. e., the policy, the transformation of conflict group's state is designed. What's more, C# is used to realize the simulation. The results show that management measures are effective to solve trans-boundary water resource conflict. The government should raise the policy implementation degree of conflict agents to alleviate local water conflicts.

Li S.Y.,Tianjin University | Tao J.H.,Tianjin University | Yu L.,Haihe River Water Conservancy Commission
Advanced Materials Research | Year: 2013

Drinking water sources play an important role in assurance of life safety, normal production and social stability. In this paper, a real-time remote water quality monitoring and early warning system has been developed. The paper concentrates on the system architecture and key techniques of the real-time water quality monitoring and early warning. The implementation of the system by advanced water quality sensor techniques, wireless transmission, databases and water quality modeling is retraced in detail. It can be applied to the real-time remote monitoring of water quality and decision support for water pollution incidents. © (2013) Trans Tech Publications, Switzerland.

Li S.Y.,Tianjin University | Tao J.H.,Tianjin University | Yu L.,Haihe River Water Conservancy Commission
Advanced Materials Research | Year: 2013

Zhangweinan basin is a typical area where has the most serious water resource shortage and water environmental deterioration problems in north of China. To improve the increasingly deteriorated water eco-environment, studies on the integrated management of water resources and water environment in the basin were carried out with focus on the prevention and control of water pollution, and based on which, an integrated management platform on water environment was developed. This paper introduces the platform architecture and elaborates the construction process of the total pollutant load control model and pollution incident early warning model. This platform provides technical supports for weakening the total pollutant load in the basin, reducing the pollutant load flowing into the Bohai Sea, and increasing the eco-flow of river channel and flow into the Bohai Sea. © (2013) Trans Tech Publications, Switzerland.

Li S.Y.,Tianjin University | Tao J.H.,Tianjin University | Yu L.,Haihe River Water Conservancy Commission
Advanced Materials Research | Year: 2013

In order to improve the capacity of integrated management on water resources and environment at county water conservancy and environmental protection departments, a knowledge based system for integrated water resources and environment management have been developed and operated at 16 counties in the north of China. The information technologies such as knowledge discovery approaches, GIS and middleware have been applied in the development of the system. The System provides services of information management, business management, including permit management of water intake and pollution discharge. The integrated management planning platform was developed based on SWAT model. These services of the system have significantly improved the capabilities of information exchange and sharing as well as the integrated water resources and environment management at county level. © (2013) Trans Tech Publications, Switzerland.

Li Z.X.,Haihe River Water Conservancy Commission | Ma Z.Z.,Haihe River Water Conservancy Commission | Li L.X.,Haihe River Water Conservancy Commission | Wang D.W.,China Aerospace Science and Technology Corporation
Legislation, Technology and Practice of Mine Land Reclamation - Proceedings of the Beijing International Symposium Land Reclamation and Ecological Restoration, LRER 2014 | Year: 2015

At large watershed scale, ecological restoration is a complicated and systematic project which involves ecological objects with various types, space layouts and area ratios. Combinations of different ecological restoration measures, such as forest and grass implementation, grazing prohibition, breeding shed and integrated governance, also have different effects on soil and water conservation. Haihe River Basin is one of the Chinese seven major river basins, with an area of 320,600 square kilometers. How to conduct ecological restoration comprehensively and effectively has been the focus of Haihe River Water Conservancy Commission. Based on current conditions and characteristics of the Haihe River Basin-soil erosion, soil conservation, ecological construction and existing problems of ecological restoration, this paper analyzes different geographic and ecological characteristic of small river basins within Haihe River Basin, such as the Yongding, Daqing and Luan rivers. According to our analysis, different integrated measures for soil and water conservation are proposed, and proved to solve soil erosion of these small river basins effectively. These integrated measures not only accelerate vegetation watershed restoration and ecological reconstruction but also improve self-repair capability of great significance. © 2015 Taylor & Francis Group, London.

Zhang J.,Zhengzhou University | Ding Z.,Haihe River Water Conservancy Commission | You J.,China Institute of Water Resources and Hydropower Research
Journal of Hydrology and Hydromechanics | Year: 2014

River runoff and sediment transport are two related random hydrologic variables. The traditional statistical analysis method usually requires those two variables to be linearly correlated, and also have an identical marginal distribution. Therefore, it is difficult to know exactly the characteristics of the runoff and sediment in reality. For this reason, copulas are applied to construct the joint probability distribution of runoff and sediment in this article. The risk of synchronous-asynchronous encounter probability of annual rich-poor runoff and sediment is also studied. At last, the characteristics of annual runoff and sediment with multi-time scales in its joint probability distribution space are simulated by empirical mode decomposition method. The results show that the copula function can simulate the joint probability distribution of runoff and sediment of Huaxia hydrological station in Weihe River well, and that such joint probability distribution has very complex change characteristics at time scales. © 2014.

Liu Q.,Chinese Ministry of Water Resources | Qin Y.,Chinese Ministry of Water Resources | Zhang Y.,Haihe River Water Conservancy Commission | Li Z.,Chinese Ministry of Water Resources
Natural Hazards | Year: 2015

A coupled 1D–2D hydrodynamic model linking the channel and flood detention basin for flood simulation with complex topography and irregular boundary was presented in this paper. The 1D Saint-Venant equations were used for governing flows in channel, and the four-point implicit Preissmann scheme was used for discretization. To simulate floods in flood detention basin, the 2D shallow equations were adopted as governing equations, and a well-balanced, unstructured finite-volume method was proposed for the numerical resolution. The 2D model is based on a new formulation of the classical shallow water equations in hyperbolic conservation form. The numerical fluxes are computed by HLLC algorithm, and the MUSCL–Hancock predictor–corrector scheme is used to achieve high-accuracy and high-resolution results. A simple and efficient method was proposed to reflect the coupled hydraulic connection between the channel and the flood detention basin. The novelties of the proposed model include (1) a robust method for wetting/drying treatment and (2) an efficient way to link the 1D and 2D models. The 1D, 2D, and coupled models are all tested through some benchmark cases, and numerical results validated the accuracy of the models. Furthermore, the coupled 1D–2D model was used for a real flood simulation in Jiakouwa flood detention basin, China. The flood-risk information including flood arrival time and maximal water depth was mapped using GIS. Those flood-risk maps can be used as an important decision-making basis of flood control and rescue for the flood control departments at all levels. © 2014, Springer Science+Business Media Dordrecht.

Zang C.,Nankai University | Huang S.,Nankai University | Wu M.,Nankai University | Du S.,Nankai University | And 7 more authors.
Water, Air, and Soil Pollution | Year: 2011

The relationships between pH, dissolved oxygen (DO) and chlorophyll a in aquaculture and non-aquaculture waters are assessed in this paper. The research includes the evaluation of field and experimental studies at the Panjiakou Reservoir (between Aug and Oct 2009) and the review of international data covering two decades. The results indicated that typical eutrophic non-aquaculture water had mean concentrations of chlorophyll a of higher than 10 μg L-1, and significant positive correlations were found between pH, DO and chlorophyll a. When the mean concentration of chlorophyll a was less than 10 μg L-1, no correlation was found between DO and chlorophyll a for waters with a high exchange rate or heavily organically polluted natural waters. Diurnal variations were found for both pH and DO. A corresponding significant positive correlation was found between both water quality parameters. In general, when the mean concentration of chlorophyll a was less than 10 μg L-1 within aquaculture waters of low exchange rate, only a weak or no correlation at all was found between pH, DO and chlorophyll a during summer and autumn. On the other hand, a significant positive correlation between pH and chlorophyll a and a significant positive correlation or no correlation between DO and chlorophyll a were found for aquaculture waters with a high exchange rate during summer and autumn. Strong diurnal variations for both pH and DO were identified. A significant positive linear correlation between pH and DO was found for field enclosure experiments. © 2010 Springer Science+Business Media B.V.

Wei W.B.,Haihe River Water Conservancy Commission | Yan S.K.,Basin Water
Proceedings of the 3rd Academic Conference of Geology Resource Management and Sustainable Development, GRMSD 2015 | Year: 2015

Influenced by global climate change and human activity, runoff generation of upper watershed of Chaobai River sustained less than that of ordinary years in recent years. To evaluate ecological flow satisfaction degree (EFSD) of rivers in the region, it was quantized by the standard of flow-ecological relations determined by Tennant method. Temporal distribution diagram of ecological flow satisfaction degree (TDDEFSD) was formed by confirming the 7-years EFSD of the two main tributaries, Chao River and Bai River, by month. Overall level of EFSD of the two tributaries was evaluated by the diagram, and the level variation through seasons and from upstream to downstream be also analyzed. For practice, the issues needed to be paid attention to during water resource development and utilization, were proposed from the water eco-environmental perspective.

Loading Haihe River Water Conservancy Commission collaborators
Loading Haihe River Water Conservancy Commission collaborators