There is a famouse saying: Oranges grown in southern is orange,but when it grown in northern,its trifoliate orange,climate is very different for the water ,weather,soil.In northern china,the climate is dry and colder than south,as we know,in southern part of china,there re a lot of river and lakes,changjiang river runs across of south china,although huangriver is a long bank river,but its less quantity water ,some where of western part nearly dry up,so its lack of water,the air is not humidy,the wind blows much dust,it cause a bad enveroment,the scientist think out an idea- an engerneering diverse water from south to north,it relieve the water shortage situation of northern china.

Except the quantity of water,the quality is very different,in south china,the water is very soft and somewhere it's a little bit sweet ,there re many springs in south of sweet water,contain many minerals,so people drink water there re very healthy.some residents dig well to get water,it s very nature no little polluted,not like the water in urban,some water from the polluted river,and very heavily polluted,eventhough its filterred in the factory,but we must boil it for drink,so it's a big problem,we need drink good quality water every day.

Anyway,we should save water and cherish it,because its limited resouce on the earth,as well as mineral and gas,we should use it properly,don't waste the limited resource.it s our responsibility to protect water resource on th earth.

Ih the old history,there re plenty of water engineers,du jiang yan of hubei province is famouse,its made in qin dynasty and desighned by libing. It is still in use today and still irrigates the plain in the region,as a result of that, The irrigation made the flat became the most productive agricultural place in China.