[Ecosystem service valuation of Ertan Reservoir watershed in mitigating reservoir sand sedimentation].
By using software ArcGIS 9.2, an evaluation model was established to simulate the ecosystem service of Ertan Reservoir watershed in mitigating the sand sedimentation in the reservoir. In the meantime, sediment delivery ratio and universal soil loss equation were used to simulate the spatial patterns of the annual sediment yield and sediment retention in the watershed as well as the value during the service life period. In 2000, the total quantity of soil retention in the watershed was 12. 1 x 10(8) t x a(-1). The region with higher soil retention was near the main and branch streams of Yalong River, and that with higher sediment delivery ratio was near the streams and the Ertan Reservoir. The region with higher sediment yield and sediment retention was around the reservoir. The actual sediment yield in the study area was 629.3 x 10(4) t x a(-1), occupying 12.7% of the actual soil erosion volume. Farmland was the most important source of sediment yield, with its sediment yield occupying 62.9% of the total. The contribution of forestland to the mitigation of reservoir sand sedimentation was higher than that of the other lands on a per unit area basis. For the reservoir's designed operating life (100 a), the total value of the watershed in the service of mitigating Ertan Reservoir sand sedimentation was 2.75 billion yuan.
Wu
Nan
N
Chengdu Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China. wunan0223@163.com
Gao
Ji-xi
JX
Sudebilige
Ennaanay
Driss
D
Mendoza
Guillermo F
GF
Luo
Zun-lan
ZL
Li
Dai-qing
DQ
Tian
Mei-rong
MR
D002681:China; D003198:Computer Simulation; D003247:Conservation of Natural Resources / Q000191:economics / Q000379:methods; D004463:Ecology / Q000379:methods; D017753:Ecosystem; D004784:Environmental Monitoring / Q000379:methods*; D019015:Geologic Sediments / Q000032:analysis*; D008962:Models, Theoretical; D045483:Rivers; D012822:Silicon Dioxide / Q000032:analysis; D014873:Water Pollutants / Q000032:analysis*
D014873:Water Pollutants; D012822:Silicon Dioxide