The Study Of Yanqi Basin Irrigation Agricultural Sustainable Development Under The Control Of "Three Red Lines" System

On January 12,2012, the statecouncil enactted the strictest water resources management system idea, the idea commonly known as the "three red lines", namely "the development and utilization of water resources control red line" " water efficiency control red line " water function limit red line ", the ideas aim at resolve the shortage of water resources and serious water pollution, the deterioration of water ecological environment as the starting point, strict control of the amount of water, improve water use efficiency, strict control pollution gross into the lakes.In recent years, Yanqi basin faced with the contradiction between supply and demand of water resources, groundwater use seriously, low efficiency of water use, water ecological balance destruction question, based on this, the article first systematic analysed the relationship between the groundwater level change and irrigation agriculture, and then, the condition of groundwater resource development an utilization’s unsustainable with the red line quota’s feasibility are verified by numerical model. At the same time, put forward the yanqi basin irrigation agriculture sustainable development mode under the "three line" system.Theresearch mainly draw the following conclusion:(1) Since 2000, the new conventional irrigation farmland area added 1× 104hm2, ground water level on average drop of 0.15 in, new drip irrigation and efficiently under the membrane water saving cultivated land area added 1×104hm2,underground water level drop of 0.25 m on average.In 2000 average groundwater level depth of 4.98 m, in the study area in 2007 and 2011, down to 5.65 and 6.86 m. Respectively, in order to prevent the underground water level drops further, no new land reclamation.(2) According to the regional hydrogeological conditions, the use of Processing MODFLOW groundwater numerical model is established, and the present situation of groundwater resources 6.92×10 m3/a, and agricultural irrigation mode is loaded into the model run, run to 2030, a great change of the groundwater seepage field compared to 2011, the underground water levels fall, basin large areas of the underground water buried depth is lower than the safety ecological water level, great effects on the ecological, it is unfeasible development plan.(3)Loading the "three red lines" index:surface water 9.75x 108m3/a, groundwater 3.9x 108m3/a in 2020; Surface water 10.1×108m3/a, groundwater 4.04x108m3/a in 2030;Verify its possibility, validated, the groundwater depth has experienced the first falling, rising after two stages, in 2019 dropped to the lowest. In ten years from 2020 to 2030, groundwater level gradually return to a reasonable level.As a result, the index is feasible.(4) According to the "three red lines" index allocation of water use and regulation must achieved water efficiency to planning basin irrigation agriculture development model, through comparative study, by 2020, efficient water-saving irrigation area increases to 15x104hm2, conventional irrigation area reduces to 7.4×104hm2, efficient water-saving irrigation efficiency increases to 0.9, conventional irrigation irrigation efficiency reaches at 0.69, consume water 15.48×108m3; By2030, the efficient water-saving irrigation area increase to 16×104hm2, conventional irrigation area decline to 6.4x104hm2, efficient water saving irrigation water use efficiency increase to 0.93, conventional irrigation water use efficiency increase to 0.7, the water consumption of 14.89×108 m3.Its the best model in Yanqi basin irrigation agriculture sustainable development.