Research On The Ecological Service Benefits Of Windbreak And Sand Fixation With Different Sand Barriers

The evaluation of ecological service benefits in desert areas is helpful to quantitatively analyze the effects of wind-proof and sand-fixing measures,and provide scientific reference and decision-making for regional ecological management and sustainable development.Over the years,scholars at home and abroad have carried out a lot of meaningful work and achieved many results.The evaluation indicators and methods based on ecological management projects and grassland desertification are often used in previous studies.In recent years,with the continuous development and improvement of wind erosion models and airflow trajectories models,more and more researchers began to combine models to study the ecosystem service benefits of ecological management in desertified land.The Kubuqi Desert is prone to long-distance transmission during sandy weather,which affects the air quality of downwind cities,especially the Beijing-Tianjin-Hebei region.In order to explore and establish a suitable ecosystem service effect system,the WEPS wind erosion prediction system is combined with the HYSPLIT model to spatially analyze the PM₁₀dust release of different ecological backgrounds in the Kubuqi Desert.Futhermore,the forward trajectory simulation was carried out based on the PM₁₀ high-release area.Finally setting up different sand barriers,The ecological service benefits under different governance measures were studied and the impact on the downwind cities was calculated and compared.The main research results of this article are:(1)The amount of PM₁₀ released by different land cover types and soil types is different.The annual average PM₁₀ release of grassland aeolian soil and meadow aeolian soil is the largest,with a PM₁₀ release of about 3 kg·m^-2.The annual average PM₁₀ release of salinized fluvo-aquic soil and fluvo-aquic soil is the second,with a PM₁₀ release of about 0.9 kg·m^-2.The annual average release amount of alluvial soil is about 0.7 kg·m^-2.The annual average PM₁₀ release of brown calcic soil,light chestnut soil,and light brown calcic soil is the smallest,and their PM₁₀ release amount are about 0.005 kg·m^-2.For the ecological background of the same soil type,the grids with the land use type of desert and saline-alkali land are prone to produce more PM₁₀ release;followed by bare land and dry land;while the average annual PM₁₀ release of vegetation areas is the smallest.(2)The release of PM₁₀ from different ecological backgrounds in the Kubuqi Desert exhibits the following laws:The high PM₁₀ release area is mainly located in the central part of the Kubuqi Desert.The soil is mainly grassland aeolian sandy soil and meadow aeolian sandy soil.Most of the cover types are deserts;the eastern part is dominated by new soil and grassland aeolian sandy soil in total PM₁₀ emissions in 10 years;The southwest is dominated by fluvo-aquic soil,light brown calcite,and brown calcite,with bare land This area is the area with the lowest annual PM₁₀ release in the Kubuqi Desert.The low PM₁₀ release area in the northern edge and central part of the Kubuqi Desert is related to the cutting and management of the border forest in the Kubuqi Desert.(3)The cities around Kubuqi Desert such as Ordos,Wuhai,and Shizuishan are most affected,with a WCWT contribution value of more than 150?g·m^-3;The southwest direction is the second.The WCWT contribution value of Yinchuan,Wuzhong,and Zhongwei cities that affect the Ningxia Hui Autonomous Region is more than 150?g·m^-3;Qingyang City,Gansu Province,Xianyang City,Yulin City,and Yan'an City in the south,passing southeast When Henan Province reaches Hubei and Anhui Provinces,the WCWT contribution value is above 100?g·m-3,and there are a large number of high value areas above 200?g·m^-3;The northern direction crosses Bayannaoer City in Inner Mongolia to reach the territory of Mongolia.WCWT contribution value is around 150-200?g·m^-3;The transmission distance of PM₁₀WCWT in the east is the longest,passing through Hohhot,Shanxi,Datong,Zhangjiakou,Chengde,and Beijing to reach Liaoning Province.Chaoyang City,Fuxin City,and finally Heilongjiang Province,its WCWT contribution value is around 100-200?g·m^-3;The west direction has the lowest impact,and the Alxa League in Inner Mongolia and Jiuquan City,Gansu have a WCWT contribution value of 50-150?g·m^-3.(4)Combining the WEPS wind erosion prediction system with the HYSPLIT model,setting up different sand barriers to evaluate ecological benefits,in terms of the annual reduction of PM₁₀ release and the daily reduction of PM₁₀,the reduction of different ecological management measures presents the following characteristics:Pinus sylvestris 1Year>Reed sand barrier>Pinus sylvestris 5 years>Nylon sand blocking net>Haloxylon sylvestris>Pinus sylvestris 10 years>Pinus sylvestris 20 years.In terms of the WCWT contribution value,the reed sand barrier reduces PM₁₀ transmission in all directions.The WCWT contribution value is less than 100?g·m^-3,and the transmission in the east and southeast directions is basically reduced to below 50?g·m^-3.Pinus sylvestris reduced the contribution of WCWT in all directions to 100?g·m^-3 in one year.The remaining sand barriers reduced the WCWT contribution value of PM₁₀ transmitted from Kubuqi Desert to less than50?g·m^-3.Combine population and GDP data with WCWT analysis results,and evaluate social and economic benefits based on the coupling model:The characteristics of the distribution of cities affected by the transmission of PM₁₀ in the Kubuqi Desert are:the urban areas around the Kubuqi Desert and the east of the Kubuqi Desert The affected area in the south is large and the PM₁₀ concentration is high;while the GDP and population in the southeast and east of the Kubuqi Desert are greatly affected by the transmission of PM₁₀ in the Kubuqi Desert,and the sand barriers have alleviated the Kubuqi Desert to a certain extent.The affected GDP and population of the leeward cities,especially the provinces and cities in the south and southeast.