甘肃省武威市风力侵蚀分区治理规划及措施

Regionalization and Prevention Countermeasures for Wind Erosion in Wuwei City of Gansu Province

[目的]分析甘肃省武威市风力侵蚀空间动态变化特征,确定风力侵蚀可治理区划及其防治对策,为该市风蚀水土保持工作和生态环境建设提供科学参考。[方法]基于多源地理信息数据,应用遥感、地理信息系统(ArcGIS)等技术手段,使用修正土壤风蚀方程(RWEQ)计算武威市2000—2020年5期风蚀模数,获得区域风蚀的面积分布和变化特征。结合重点建设工程分布等空间要素叠加分析方法,提出该市风力侵蚀可治理区域划分原则,并将该原则应用于划分武威市风力侵蚀可治理区。[结果]修正土壤风蚀方程(RWEQ)能较好地估算武威市多年风力侵蚀模数,其多年风力侵蚀模数为5788.98〔t/(km^(2)·a)〕,多年平均土壤风蚀总量1.92×10^(8)t;研究区风力侵蚀在时间上呈现总体下降,偶有上升趋势,且风力侵蚀强度等级明显减弱;在空间上具有明显的空间异质性,主要分布在民勤县、凉州区、古浪县;依据多要素叠加风蚀分区治理方案,武威市可治理风力侵蚀面积共2872.66km^(2),其中民勤县1468.48km^(2),凉州区708.75km^(2),古浪县695.43km^(2)。[结论]风力侵蚀分区治理是武威市风蚀水土保持的重点工作,根据风蚀分区治理划分结果,针对不同行政区划,民勤县北部坡度较低的平坦戈壁沙漠地区是其重点关注区域,治理措施应以风沙防治和植被恢复为主,并需要注意控制人为工程建设扰动的影响,明确区域管理范围;凉州区应注意采取工程措施和生物措施结合的方式进行治理;古浪县应以封育措施和对天然植被进行保护为主。同时,在戈壁沙漠地区需特别注意大型光伏电站建设等施工扰动的风沙防治和生态恢复。

[Objective]The characteristics of the spatial dynamics of wind erosion at Wuwei City,Gansu Province and the controlled area of wind erosion and its prevention countermeasures were determined in order to provide scientific references for implementing measures to prevent wind erosion,conserve soil and water,and use ecological environmental construction practices in the city.[Methods]Multi-source geographic information data,applied remote sensing,a geographic information system(ArcGIS),and other technical means were used with the revised wind erosion equation(RWEQ)to calculate the five-period wind erosion modulus of Wuwei City from 2000 to 2020 to obtain the distribution of the regional wind erosion area,change characteristics,etc.These results were combined with a superposition analysis of spatial elements(such as the distribution of key construction projects)to put forward the principles of the city's wind erosion manageable area delineation and to apply them to delineate the manageable area of wind erosion at Wuwei City.[Results]RWEQ was able to estimate the multi-year wind erosion modulus at Wuwei City[5788.98 t/(km^(2)·yr)],with a multi-year average soil wind erosion of 1.92×10^(8)t.The model exhibited an overall decreasing and occasionally increasing trend over time,and the wind erosion intensity level was obviously weakened.Wind erosion intensity exhibited obvious spatial heterogeneity that was mainly located in Minqin County,Liangzhou District,and Gulang County.According to the multi-element superimposed wind erosion zoning management program,Wuwei City can manage a total of 2872.66 km^(2)of wind erosion area,of which 1468.48 km^(2)was at Minqin County,708.75 km^(2)was at Liangzhou District,and 695.43 km^(2)was at Gulang County.[Conclusion]Wind erosion sub-area management should be the focus of wind erosion prevention and soil and water conservation in Wuwei City.According to the results of the wind erosion sub-area management division,for different administrative divisions,the flat Gobi desert area with low slope in the northern part of Minqin County is the key area of regional concern.Management measures should be based on the prevention of wind and sand erosion and the restoration of vegetation cover,and attention should be given to controlling the impact of man-made engineering and construction disturbances to make clear the scope of the regional management.Liangzhou District should focus on using a combination of engineering measures and biological measures,combined with governmental management.Gulang County should focus on closure measures and protecting natural vegetation.At the same time,special attention in the Gobi desert area should be given to the implementation of wind and sand erosion prevention and ecological restoration measures for construction activities such as large-scale photovoltaic power plants.