11.2　Scope and Standard of Land Requisition

11.2　Scope and Standard of Land Requisition

11.2.1　The treatment scope of land requisition shall include areas to be influenced by reservoir inundation and construction areas of project.

11.2.2　The flood backwater surface profile of reservoir shall be calculated based on the design flood standards for different inundated objects respectively，which shall be defined by using the backwater elevation of the envelope curve formed by natural flood upstream of the dam site and flood backwater levels at same frequency in flood season and non-flood season after the reservoir is built.The feathering out point of reservoir backwater shall be defined by the cross section where the backwater surface profile has a 0.3m difference with the natural flood surface profile of the same frequency.The design end point of the terminal of reservoir backwater may be determined，according to the inundation extent at the tail of the reservoir，at the intersection of the horizontal extension of the feathering out point level and the corresponding water surface profile of annual mean discharge in the natural river course.

11.2.3　The standards of design flood for the inundated items of reservoir should be selected within the scope as shown in Table 11.2.3.If the lower limits are adopted，specific analysis and demonstration shall be carried out.

Table 11.2.3　Standards of design flood for different inundated items(https://www.daowen.com)

For railways，roads，electric and telecommunication lines，cultural relics，and water facilities，the standards of design flood shall be defined according to Standard for Flood Control GB 50201；if there is no specific provision，the relevant authorities shall be consulted to determine the relevant standards.

Where protective engineering measures，such as blocking up and embankment，will be taken for the inundated regions of reservoir，the standards of design flood shall be finalized according to the importance of the protected objects and shall conform to the provisions in the current relevant national standards.

11.2.4　The boundaries for resident relocation and land requisition shall be analyzed and finalized by integrating the specific situation of aforesaid scope of areas influenced by reservoir inundation and construction areas of projects，and with the consideration of a certain freeboard for the reservoir as well.For the front part of dam where the impact of backwater is not significant，the swash heights of both the wind waves and ship waves shall be calculated，and the bigger value will be taken as the freeboard of reservoir.If the reservoir freeboard for the boundary of resident relocation is lower than 1.0m，it should be 1.0m；if the reservoir freeboard for the boundary of farmlands and gardens requisition is lower than 0.5m，it should be 0.5m.