2017’s State Natural Science Award in China, entitled “Nonlinear Mechanism of Runoff Generation & Transformation in Basin”, was awarded to Prof. Xia Jun and his team.
The State Natural Science Award (SNAS) in China, established in 1955 by the State Council, awards the laureates who have made major scientific discoveries in clarifying natural phenomena, characteristics and laws in basic research and applied basic research. The award project lead by Prof.J.Xia has made major scientific discovery on the nonlinear mechanism of runoff generation & transformation in basin scale. Three nonlinear characteristics and laws, namely the runoff generation, the evapotranspiration, and distributed system were clarified, and relative models were developed that were verified in China and global and successfully applied to practices. Major contributions can be summarized as follows:
This project found a nonlinear hydrological law, namely the time-variant gain runoff generation mechanism based on the system-hydrology element and long term practices in China also international.the authors clarifying a set of natural characteristics and laws in the hydrological basic research and also its applied basic research, i.e., (1) discovering general relationship of hydrologic gain for runoff generation, controlled by three key factors and their nonlinear combination, namely rainfall intensity, soil wetness and land cover types; (2) developing a new Time-Variant Gain Model (TVGM) based on hydrological nonlinear law; (3) building up the linkage of the time-variant gain model with general nonlinear response function, i.e., Volterall functional series, and gave an evidence how to build the linkage and what relationship between hydrological linear response and nonlinear response. The discovery for the time-variant mechanism of runoff generation indeed developed the nonlinear theory of hydrological systems, also significantly improving precision of runoff modelling and prediction. As my understanding, by application and verification from the “International Flood Forecasting Model Inter-comparison Project” organized by the World Meteorological Organization (WMO) and University College Galway (UCG), this theory and TVGM model are tested by using the datasets from more than sixty river basins at different representative climatic regions across the world. The results showed that compared with linear models, the developed nonlinear theory and TVGM can increased accuracy in runoff prediction by up to 63% with an average of 45%.
An evapotranspiration nonlinear mechanism for the transformation at the interface of water and “Soil – Plant – Atmosphere -Continuum” (SPAC) was also found. For the runoff estimation, when short term storm floods moves to daily and monthly runoff processes, the evapotranspiration becomes a key issue. This project have following two original researches: (1) A nonlinear relationship among soil wetness, LAI and evapotranspiration in SPAC system and exploration of the evapotranspiration mechanism in runoff generation, that revealed the nonlinear conversion mechanism between water and energy at the interface of the SPAC system, which is mainly characterized by changes in evapotranspiration. The findings theoretically determined the impacts of soil evaporation on the transformation of “five kinds of water”, and provided a scientific basis for the simulation of vertical water movement in the runoff generation and transformation processes; (2) Development of a new evapotranspiration estimation model related to crop growth and spatial variability based on the study of water and energy conversion in the SPAC system and integration of remote sensing information, which revealed the combined effects of land surface impedance, energy transfer, soil water movement, canopy interception and surface runoff and other factors on the spatial and temporal variability of evapotranspiration. These novelty study was successfully applied to water wisely management in North China that was seriously water shortage area in the word.
This project developed novelty of research on quantifying distributed system nonlinearity through coupling spatially-distributed properties and multiple hydro-physical processes based on nonlinearities of time-variant runoff generation and evapotranspiration. (1) Developing a nonlinear Distributed Time-Variant Gain Model (DTVGM) based on the spatial and temporal variation of runoff generation and transformation at basin scale, which revealed the interactions among basin water cycle, climate change and human activities. For instance, through DEM and GIS, the linkage relationship between the time-variant gain factor (G) and spatial variation of underlying land-use and cover-change was found, and also the impacts of high-intensity human activities, such as building dams and sluices and large water transfer projects can be coupled with DTVGM to quantifying impact of environment change; (2) Development of a new approach to quantify the sensitivity and uncertainty in hydrological modelling and its parameter set estimations. Proposed method can significantly reduce the band of the uncertainty intervals and can efficiently overcome the drawbacks of low efficiency in traditional sensitivity method, and finally improve the reliability of the parameter estimation in the DTVGM model. These new models and methodologies were successfully applied to integrated water quality and quantity operation in the Huai River Basin, adaptive water management for the South-to-North-Water-Transfer Project, which has brought prominent social and economic benefits.
Anyhow, the project did original and novelty of researches in developing TVGM and it distributed models and the uncertainty of parameters estimations. The eight representative papers have been externally (non-self) cited by 725 times, where the external SCI citations reached 577 times and the most cited paper has 151 external citations. Also, this new research were applied to China and international for river flow forecasting and flood control, water resources management to product significant benefits for social & environment. Owing to the outstanding contribution to hydrological sciences, Prof. Jun Xia was awarded the 2014 INTERNATIONAL HYDROLOGY PRIZE-The Volker Medal for him and his team’s “outstanding contributions to the sciences of Hydrology and application of his research and hydrological expertise to the benefit of society”. It is awarded by International Association of Hydrological Sciences (IAHS) with the support of World Meteorology Organization (WMO) and United Nations Educational, Scientific and Cultural Organization (UNESCO).
International Hydrology Prize-Volker Madel, 2014
The 2014’s International Hydrology Prize-the Volker Medal is awarded to Prof. Xia Jun who have made outstanding contributions to the science of Hydrology and applied their research and hydrological expertise to the benefit of society. It is awarded by the International Association of Hydrological Sciences (IAHS) with the support of the World Meteorological Organisation (WMO) and the United Nations Educational, Scientific and Cultural Organisation (UNESCO).
Citation for XIA Jun, at the awarding of the IHP-Volker medal 2014, given by Prof. Huber Savenije, President of IAHS:
Prof. XIA Jun graduated from Wuhan University (WU), completed his PhD on Hydrology in 1985, and has been Professor of Hydrology and Water Resources since 1991 at this same university. He has been the Chair Professor & Director of the Key Laboratory of Water Cycle in the Chinese Academy of Sciences since 2000, Director of the State Key Laboratory of Water Resources & Hydropower Engineering in China (2002-2006), and Dean of the Research Institute for Water Security.
Prof. Xia is recognized for his outstanding and lifelong achievements and contributions to develop water science and improve water management in China, and in the world in general. Particularly worth mentioning are:
(1) Promoting the hydrological science basis for sustainable water utilization by developing a nonlinear time-variant system approach and sustainable water management policy as an engine for social & economic sustainable growth. Prof. Xia developed a non-linear time-variant model, which was tested and verified in over 60 basins in different climatic regions of the world. This research has significantly improved our understanding of water-land-environment-human-ecosystems interactions, potential impacts of climate change on water planning and management processes, and scientific management of river basins;
(2) Promoting a new paradigm for a water system approach in large basins to deal with conflicts in the operation of flood control & environmental protection, and ecological operation in river system of developing countries. His scientific practices on the Huai River Basin helped more than 160 million people in the basin to avoid disaster from water pollution through integrated water quality and quantity management. His research & practice on eco-water use & operation based on water system approach in Xingjiang of West China, have brought benefits to improving the living environment of an 11 million multi-ethnic population and preventing serious degradation of the ecological system of the Tarim river, the biggest inland river basin in China and the 3rd in the word, that once suffered the dying up of a 400 km long river reach and the near death of 85% of an indigenous forest;
(3) Playing a leading role in professional water institutions such as IAHS, IWRA, WWC, which have contributed to improved water governance in the world, particular in China. Prof. Xia made substantial contributions to improving cooperation and collaboration between water professionals from China and the rest of the world. In his roles as Vice President of the International Commission for Water Resources System of IAHS (1996-1999), Vice President of IAHS (2004-2007), President of the International Water Resources Association (2010-2012), and so on, his contributions to North-South and South-South knowledge and experience transfer have been very significant.
Prof Xia Jun also had an immense impact on the formation of water resources managers and hydrologists. As a teacher, he has educated and influenced a new generation of water professionals who will undoubtedly contribute significantly to efficient and equitable management of water in China, both in terms of quantity and quality. He has an impressive list of publications with 420 technical papers and 30 books he edited, both international and Chinese. These have had major impacts on improving understanding of hydrology, and water and environmental management practices in many parts of the world.
In summary, Prof. Xia is an outstanding scientist, whose innovative work on developing knowledge and strategies in hydrologic sciences and its application to water management and sustainable development in China and the world has made a major contribution to the international society.
Prof Xia Jun is the first to receive the prestigious Volker medal of IAHS/Unesco/WMO. I am glad to say that he is an excellent person to lead the Volker medal dynasty that will hopefully follow him, and to serve as an example to the hydrological community in the spirit of Prof Adriaan Volker, who like Xia Jun was very much dedicated of bringing hydrological science into practice for the benefit of society and the developing world in particular. It is an honour to award the first Volker medal to Prof. XIA Jun, for outstanding contributions to the science of Hydrology and application of his research and hydrological expertise to the benefit of society. (http://iahs.info/About-IAHS/Competition--Events/International-Hydrology-Prize/International-Hydrology-Prize-Winners/XiaJun/)
International Prize for Outstanding Contributions to Water Management in 2011
Prof. Jun XIA awarded by “The InternationalPrize for Outstanding Contributions to Water Management”. The Third World Centre for Water Management awarded its International Prize for Outstanding Contributions to Water Management to Prof. Jun Xia on October, 2011. Prof. Xia was recognised for his "outstanding and lifelong achievements and contributions to improve water management in the world in general, and in China in particular". One of the important contributions of Prof. Xia has been to develop a non-linear time-variant model which was tested and verified in over 60 basins in different climatic regions of the world. The work carried out by Prof. Xia has significantly improved our understanding of water-land-environmenthuman- ecosystems interactions, potential impacts of climate change on water planning and management processes, and scientific management of river basins. Through his role as a teacher, he has educated and influenced a new generation of water professionals who will undoubtedly contribute significantly to efficient and equitable management of water in China, both in terms of quantity and quality”. The Award also commended Prof. Xia for his "contributions in improving cooperation and collaboration between water professionals from China and the rest of the world. In his roles as President of the International Water Resources Association, Vice President of the International Association of Hydrological Sciences and a member of the Board of Governors of the World Water Council, his contributions to North-South and South-South knowledge and experience transfer have been very significant". Prof. Xia is the first winner of this Prize. He received this prestigious Award from Prof. Asit K. Biswas, President of the Third World Centre for Water Management and a former IWRA President, on 21 October 2011 during the Xi’An International Symposium. (Newsletter of IWRA, 24(4), p2, December,2011)