Hydrological Characteristics Of Shaoyang In Zi River And Urban Land Expansion Of Shaoyang

With the sharply increasing development of urbanization, the land use of the city is increasing at the same time and the settled site of construction and extension has a lot to do with the hydrological characteristics of the local place. With the raining characteristics of Shaoyang as the entering point, this paper analysis the hydrological characteristics have an effect on urban expansion of Shaoyang city. It also provides scientific proofs for the urban expansion of Shaoyang.The researching unit of the paper is Shaoyang and the materials of the past decades are the basic datas. This paper focuses on some main stations, including Luo Jiamiao, Huang Qiao, Shaoyang and Mao Ping,whose raining amount, flowing amount annual and seasonal change of water resource, cumulative curve change over the years and the reasons for drought and floods are being carefully analyzed in the paper. As Luo Jiamiao is the meeting point of Zi River, the paper also analyzes the annual flowing amount of this observatory. The analysis indicates that either the annual change or the seasonal change of the raining water amount is large. The runoff has a clearly positive relation with the precipitation. From the cumulative departure curve, it can be easily seen that the change of the precipitation in a very long time has a continuity. According to the datas of the annual precipitation of Luo Jiamiao, the dependence before and after is weak.Hydrological characteristics is the'threshold" of the land extension of a city, in which, water resource and the highest flood level are the most effective. The relation between the total amount of water and the extension of urban land use is apparently positive. What's more, the change of seasonal distribution is greatly large. There are lots of floods in the section of Zi River, which flows from the southwest to the northeast. Other sections, except Niwan and Small Jianghu, are in the natural state. All of these lead to the strip and deep development along the Zi River of Shaoyang's urban expansion.Most areas along the river are in the flood-controlling scope near Shaoyang in Zi river, whose P equals 10% (P stands for the frequency of floods). Since the PRC established, the repeated period of the highest flood level is 40 years, so the criterion of flood control should be up to once in 40-year. After careful consideration of the influence of water resource and the floods, the urbanization of Shaoyang is extending from the southwest where Tang Family lives to the northeast. It is also extending along the Shaoshui River. As Liu Family lives could not withstand 10-years frequency flood, it can not be the subject construction...