(1)当地长江水的含沙量:ρ= 15g 1L = 15 1000 kg 1×10?3m3 =15kg/m3,(2)每小时水的流量:V=1000m3/min×60min=60000m3,∵ρ= m V ,∴每小时将流失泥沙:m=ρV=15kg/m3×60000m3=9×105kg.故答案为:15;9×105.