An underground mine development project has a 560 m shaft sinking whose diameter is 5 m; three sublevel tunnels planned at 440m, 500m and 560m, respectively; and a decline to the 560 m level. The decline (cross section 5 m x 5.6 m) development has reached the 500 m level, and the tunnel (cross section 5 m x 5.6 m) development at the 440 m level has extended 200 m towards the shaft direction. Unfortunately, the decline development at the 500 m encountered major groundwater inrush and flooded the entire decline and the 440 m level tunnel. An overflow of 50 m3/hour is measured at the portal of the decline. Design a pumping system to dewater the flooded mine developments. To complete the design, your design report shall cover the following three components: 1) Overall pump stages of the pipeline and pumping system, including: the overall pumping strategy to pump the water from underground to ground surface, your own layout design drawing, and total pipeline length. 2) How long will it take to dewater the flooded space? Assume that the pump has an efficiency of 90%. Detail any other assumptions used in the design and calculation. 3)