Countermeasures of ecologic phreatic water protection and mine water disaster prevention in northern Shaanxi Coalfield

in order to mine the coal resources of northern Shcanxi Jurassic Coafred and while to actively protect the phreatic aquifr in the Quatemnary SalawusuFormation with important ecological signfcances,based on the Coalield special seam-underground water space combined relationship.,an experimen comparson method was appied to study the igh intensity cal mining to the interference law of the ecologic phreatic water fow rfed and provided the optimized adjustment and contol stralegy of the ecologic phreatic water fow rield in order to protect the underground water resources and to prevent and conrol the mine water disaster The studly resuts showed that the cal mining inerference intensity to the ecologic phreatic water fiow fed would depend on the water fovwing crack zone to thefalre degree of te key water isolated layer.The develogment height of the water fowing crack zone was mainly controld by th mining intensity of the seam .The heghtlinit minin scing mining .bac .1l ing .rea linit mining,trpe mining and other cal mining technique were appied to control the develoment height ofthe waterfowing crack zoneand to proect the key water isclated layer without any falure and could be an effictive acesstorealize the target of the water keeping coal mining. n the coalfeld with above suitable condtions,the above mining technology conducted would be favorable to the protect the underground water resources and the mine safety