a great feedback with them between human decision making human action and what s happening on the landscape. to minimize flood risks three hundred years ago the japanese diverted to turn a river to make it flow into the pacific ocean instead of the bank of tokyo. the huge canal dug in the twentieth century also helps to drain excess water. thanks. to complete the preventative measures engineers also created a vast underground drainage network. in this complex is to handle water mainly flood water by retaining it so that there is