Ecological Water Requirements in the Lower Reaches of the Tarim River

Quantification of the ecological water requirement is an important basis for basin water rights allocation.The downstream of Tarim River from the Daxihaizi Reservoir to the Taitema Lake was chosen as studied area.The minimum ecological water requirement of the inside river was calculated with the wetted perimeter method.Based on the river groundwater distribution features during 2009-2010,the quantity of groundwater along the river sides 1 km range was calculated to recover the groundwater to the target groundwater depth of 5-4 m.The phreatic evaporation method and the quota-area method were applied to evaluate the ecological water requirement of the natural vegetation in the studied area.The results showed that: 1) The annual minimum ecological water requirement of the inside river in the lower reaches of the Tarim River from Daxihaizi to the Taitema Lake was 1.455×108 m3;2) Take 5 a as recovery period,the annual water requirement would be 0.608×108-1.466×108 m3 to recover the groundwater depth of studied area to 5-4 m;3) Ecological water requirement of the natural vegetation in the studied area was 1.042×108 m3 based on the average results of the phreatic evaporation method and the quota-area method;4) The total quantity of annual ecological water requirement in the lower reaches of the Tarim River from Daxihaizi to the Taitema Lake was 3.105×108-3.963×108 m3.