| ET is the total name of intercropping evaporation and plant transpiration, as well a continuous process in the SPAC system, and the most important parameter in river basin and regional water balance analysis. To accurately measure of ET is of very important and reality significance among climate evolvement research, water resources plan and management, water saving irrigation, and crop yield simulation and forecast. The relation between ET and precipitation was studied during the popularization practice of water-saving irrigation technique and under the situation of continuous development and utilization on water resources by people in our country, which formed the definition of Engineering-oriented Water Shortage and Resource-oriented Water Shortage, and extended the definition of ET as consumption of water resources instead of the water requirement in crop growing process in field. Thus the definition of regional integrated ET, regional water resources consumption, was posed. In resource-oriented shortage area, it is an important research direction that implementing the theoretical and practical exploration on resource-oriented water saving management, and that realizing the water resources management scheme by integration of river basin and regional. The rapid development of computer and3S (RS, GIS, and GPS) technique changed traditional ET measurement by enlarging the single crop experiment in irrigation experiment point to large scale. Remote-sensing technique made ET measurement at different special and temporal scale more directly, and made it possible for macroscopical management of ET, as well provided technical method to measure the implementing effect, established the base for water resources management based on ET. By comprehensively summarizing the implementing effect of Water Conservation Project Financed by World Bank and Global Environment Fund Hai Basin Integrated Water and Environment Management Project, the paper discussed the establishment of water resources management scheme based on ET for the Hai basin, which is a severe resource-oriented water shortage area. And put forward water saving strategic theory system of water resources management from river basin to region and from region to river basin based on ET.Firstly, the paper summarized the water resources situation and main problems existed in the Hai Basin, analyzed the research progress of ET measurement technique, contrastively analyzed advantage and disadvantage between traditional ET measurement technique and remote-sensing, and brought forward the main research emphases of water saving strategy scheme for resource-oriented water shortage area on the basis of analysis of resource-oriented water saving definition.Secondly, in the discussion of "Real Water Saving", the paper analyzed different definitions on resource-oriented water saving theory in China, comprehensively summarized the exploration and practice of Water Conservation Project Financed by World Bank on resources water-saving irrigation theory in water saving irrigation management; made basic theory analysis and implement measurement evaluation, primarily brought forward water resources management scheme based on ET, which proved that the feasibility to use new theory of water saving irrigation based on ET in resource-oriented water shortage area.Thirdly, the paper summarized the application and development of ET-WATCH model based on the energy balance in the Hai Basin. Analyzed the situation of the ET measurement and forecast technique development, summarized the advantage and disadvantage of existed models such as SEBAL, SEBS, brought forward ET-Watch model that is suitable for different ecology in the Hai Basin, established a series of parameter collection, and made technique analysis on the model validation and improvement, which provided support for annually dynamic measurement on evaporation and transpiration at river basin scale, as well briefly analyzed datus of remote-sensing ET from2002to2009at river basin scale.Fourthly, the paper expatiated the constitution process of target ET on river basin scale, defined the definition of target ET, brought forward the principle and technique route to confirm the target ET; according to the characteristic of the Hai Basin and the implementation of GEFHai Basin Integrated Water and Environment Management Project, put forward the computation method and flow of target ET, on the basis of remote-sensing measurement ET model, soil moisture model, dualistic model, and et al; from the point of resources and considering local water resources amount, precipitation, runoff in to the sea, over exploitation groundwater, and other factors such as southern water to the north, brought forward3different year level as present,2010, and2012,9scenario schemes, derived the target ET results under the9set scenario schemes through target ET computation flow, and put forward recommendation scheme through evaluation.Fifthly, the paper studied the basic method to realize water resources management water-saving strategy at the county level from the point of practical management requirement; put forward methods of regional water saving potential analysis and ET distribution in different area, confirmed the ET quota of different crop; taking crop ET quota as evaluation criterion, adjusted the pixel value that overtopped the criterion, so that the quota management water saving potential was acquired; according to the confirmed crop ET quota and analysis of effective precipitation in crop growth period, calculate crop net irrigation quota by water balance method. According to the ET management practice of Beijing city, ET management is feasible at county level.Finally, the key achievement and innovations were summarized in this paper. Some suggestions to improve the works as well as the future research outlook were given. |
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