Windbreak effects of shelterbelts in oases of the Ulan Buh Desert based on the analysis of wind speed field

  Objective  This research compared the windbreak effects of five shelterbelts with different structures and configurations based on the distribution characteristics of wind speed field, and proposed to use the fixed parameter “wind protection area” to compare windbreak effects of different shelterbelts, to obtain the wind statistical parameters, in order to provide the theoretical bases and practice patterns about shelterbelt construction in arid lands.

  Method  This paper took five shelterbelt nets with different structures and configurations as research object (the structure of shelterbelt net 1 had closely spacing of 0.13 and comprised of only trees; shelterbelt net 2 had more widely spacing of 0.24 and comprised of only trees; shelterbelt net 3 had sparse spacing of 0.27 and comprised of trees and bushes; shelterbelt net 4 had passable spacing of 0.39 and comprised of only trees; shelterbelt net 5 had sparse spacing of 0.27 and comprised of only trees) in oases of the Ulan Buh Desert, northern China. Through synchronization observation, we obtained wind speed data and analyzed the characteristics of wind speed field, wind statistical parameters andwindbreak effects in five different shelterbelt nets based on the methods of geographical and statistical analyses.

  Result  The range of wind protection efficiency in different shelterbelt nets was different. Shelterbelt net 1 ranged from 65% to 95%, shelterbelt net 2 ranged from 67% to 85%, shelterbelt net 3 ranged from 46% to 82%, shelterbelt net 4 ranged from 44% to 67%, shelterbelt net 5 ranged from 56% to 72%. Shelterbelt net 2 composed of two-line tree belt presented high wind protection efficiency above 67%. Shelterbelt net 2 was also conductive to save and conserve soil and water. Shelterbelt net 3 composed of two line bushes and two-line trees presented 2.47 times “wind protection area” of shelterbelt net 4 composed of two-line tress when the wind protection efficiency was 60%. Shelterbelt net 3 had a wide application prospect with good windbreak effect.

  Conclusion  Both shelterbelt net with more widely spacing and composed of two-line tree belt and “small grid with narrow auxiliary forest belt” shelterbelt net composed of two line bushes and two-line trees presented good windbreak effects in oases of the Ulan Buh Desert of northern China.