Design Of Diminutive Silt Retention Dam No.61 In Tianjia Trench Catchment In Dongsheng,Inner Mongolia

In order to reduce earthy material into Yellow River, conserve soil and water, improve local agricultural productivity and protect ecological environment, according to the constructive requirement of the whole group dam program in Tianjia Trench small watershed, a small-size silt storage dam for farmland construction is to be built in Tianjia Trench small watershed to perfect the structure of the Group Dam Progrom.The project design content is as follows:The project is a part of a Group Dam Progrom in Tianjia Trench Small Watershed of Kuye River, Erdos city, which is capital construction project invested by the government and executed by a qualified construction team. Based on sediment trapping, the key project tasks are divided into two parts: homogeneous earth dam and grading lying pipe culvert outlet work.The project goal is as follows:The total reservoir capacity is 42.6 thousand m~3; flood detention capacity is 27.6 thousand m~3; mud retaining capacity is 15.0 thousand m~3; the eara of silt earth is 0.76hm~2; maximum water discharge is 0.11m~3/s. the total amount of work is 9764m~3; total construction period is 60 days; total investment is 154.3 thousand RMB yuan.The project design method is field investigation and survey.The project design effect is as follows:Measuring with the design age limit of siltation, the eara of silt earth will be 0.76hm~2 which will produce 4.8 thousand kg grain every year and bring in annual income of 5.47 thousand RMB yuan for each local farmer.And 3 thousand m~3 sediment will be held up each year, which will reduce the silt into Yellow River of 3 thousand tons to make profit of 7.2 thousand RMB yuan each year. In addition, whole group dam program in Tianjia Trench small watershed will be perfected to clip flood peak, detain flood and trap sediment so that manpower, material and financial resources used for channel cleanout in lower course will be reduced largely. With impoundment of the dam, the underground water level of the downriver will rise, which is in favor of full utilization of water resource, forest plantation and basic farmland construction. And the sediment earth can help for returning land from fanning to forestry and grassland in the reservoir area,improving ecological environment radically, and improving local transportation condition as well as prompting economic development in the: watershed.