Special Water Supply Planning On The New Industry Area Of Western Town In Zhuji City Of Zhejiang Province

Recently there has been a great progress in economy in Zhuji city of Zhejiang province, especially the new industry area of western town is rapidly developed, but the planning of water supply is still lagging compared to the urban construction. This paper analyzes some factors which are related to the special planning of water supply, these factors include city's planning, construction scale, local landform, climate and current water demand etc... Some key problems, such as capacity of water supply, selection of water resources, plant location and layout of water distribution systems, also are discussed. The viewpoints in the paper could be helpful for decision making.Three methodologies, index of water consumption in each person, index of water consumption in each unit of construction land and relative ratio in various types of water consumers, are used to forecast water demand in the new industry area of western town. By comparison of the forecasting results, the capacity of water supply engineering is given as follows:110000m~3/d (Short term planning period, up to 2010)210000m~3/d (Long term planning period, up to 2020)The water quantity at consumer nodes is calculated according to the function of planning land.Several relative theorems, engineering economics and optimal design, are applied to the layout of water distribution networks, and some schemes of water pipe networks are analyzed by comparison of technical-economical index. Dynamic mathematical model considering the time value of investment is used to discuss the relationships between the pipe flow and economical diameter. The paper develops a new skill in layout of pipe lines, the shortest path and the shortest tree path are used to search for the best pipe layout scheme for a great saving of both investment and operation cost.