Estimation methods of eco-environmental water requirements: Case study

Supplying water to the ecological environment with certain quantity and quality is significant for the protection of diversity and the realization of sustainable development. The conception and connotation of eco-environmental water requirements, including the definition of the conception, the composition and characteristics of eco-environmental water requirements, are evaluated in this paper. The classification and estimation methods of eco-environmental water requirements are then proposed. On the basis of the study on the Huang-Huai-Hai Area, the present water use, the minimum and suitable water requirement are estimated and the corresponding water shortage is also calculated. According to the interrelated programs, the eco-environmental water requirements in the coming years (2010, 2030, 2050) are estimated. The result indicates that the minimum and suitable eco-environmental water requirements fluctuate with the differences of function setting and the referential standard of water resources, and so as the water shortage. Moreover, the study indicates that the minimum eco-environmental water requirement of the study area ranges from 2.84×10¹⁰m³ to 1.02×10¹¹m³, the suitable water requirement ranges from 6.45×10¹⁰m³ to 1.78×10¹¹m³, the water shortage ranges from 9.1×10⁹m³ to 2.16×10¹⁰m³ under the minimum water requirement, and it is from 3.07×10¹⁰m³ to 7.53×10¹⁰m³ under the suitable water requirement. According to the different values of the water shortage, the water priority can be allocated. The ranges of the eco-environmental water requirements in the three coming years (2010, 2030, 2050) are 4.49×1010m3-1.73×1011m3, 5.99×¹⁰m³-2.09×10¹¹m³, and 7.44×10¹⁰m³-2.52×10¹¹m³, respectively.