Longyangxia Dam

{{Short description|Dam in Gonghe, Qinghai, China}}

{{Infobox dam

| name =Longyangxia Dam

| name_official =

| image = Longyangxia oli 2017005 lrg.jpg

| image_size =

| image_caption = Satellite picture of the Longyangxia Dam reservoir and solar power park

| image_alt =

| location_map = China

| location_map_size =

| location_map_caption =

| coordinates = {{coord|36|07|20|N|100|55|06|E|type:landmark|display=inline,title}}

| country =China

| location = Gonghe County, Qinghai Province

| status =In use

| construction_began =1976

| opening =1992

| cost =

| owner =

| dam_type = Arch gravity dam

| dam_length ={{Convert|396|m|ft|0}}

| dam_height ={{Convert|178|m|ft|0}}

| dam_width_crest ={{Convert|18.5|m|ft|0}}

| dam_width_base ={{Convert|80|m|ft|0}}

| dam_volume =

| dam_crosses =Yellow River

| spillway_count =

| spillway_type =Service, gate-controlled on crest

| spillway_capacity =

| res_name = Longyangxia Reservoir

| res_capacity_total ={{Convert|24.7|e9m3|acre.ft}}

| res_catchment = {{Convert|752443|km2|sqmi|0}}

| res_surface ={{Convert|383|km2|sqmi|0}}

| res_max_depth =

| res_tidal_range =

| plant_operator =

| plant_commission =

| plant_decommission =

| plant_type =

| plant_hydraulic_head ={{Convert|122|m|ft|0}} (design)

| plant_turbines = 4 x 320 MW

| plant_capacity = 1,280 MW
1,400 MW (max. planned)

| plant_annual_gen = 6 TWh

| website =

| extra =

}}

{{Infobox power station

| fetchwikidata = NONE

| name = Longyangxia Dam Solar Park

| name_official =

| image =

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| status =

| construction_began =

| commissioned = 2014

| decommissioned =

| cost = {{CNY|6}} billion[https://www.theguardian.com/environment/2017/jan/19/china-builds-worlds-biggest-solar-farm-in-journey-to-become-green-superpower "China builds world's biggest solar farm in journey to become green superpower"], The Guardian. 19 January 2017

| owner =

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| solar_type =

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| ps_thermal_capacity =

| ps_electrical_capacity = 850 MW

| ps_electrical_cap_fac =

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}}

The Longyangxia Dam is a concrete arch-gravity dam at the entrance of the Longyangxia canyon on the Yellow River in Gonghe County, Qinghai Province, China. The dam is {{Convert|178|m|ft|0}} tall and was built for the purposes of hydroelectric power generation, irrigation, ice control and flood control. The dam supports a 1,280 MW power station with 4 x 320 MW generators that can operate at a maximum capacity of 1400 MW. Controlling ice, the dam controls downstream releases to reservoirs lower in the river, allowing them to generate more power instead of mitigating ice. Water in the dam's {{Convert|24.7|e9m3|e6acre-ft|abbr=on|adj=on}} reservoir provides irrigation water for up to {{Convert|1000000|ha|acre|0}} of land.{{cite web|title=Longyangxia Hydropower Project|url=http://www.chincold.org.cn/dams/rootfiles/2010/07/20/1279253974093926-1279253974095162.pdf|publisher=Chinese National Committee on Large Dams|accessdate=7 January 2011}}

The dam is composed of its main body and a gravity pier and secondary dam on both its left and right flank. The dam's service spillway contains two {{Convert|12|m|ft|-wide|adj=mid}} gates that discharge water into two {{Convert|260|m|ft|-long|adj=mid}} and {{Convert|280|m|ft|-long|adj=mid}} chutes. Downstream discharges are also controlled by a similar single-chute middle outlet and the lower outlet works.