纸坊沟小流域近80年来土地利用变化及其土壤保持效应OA北大核心CSTPCD

[Objective]The land use change driven by comprehensive management of small watershed can significantly affect the process of sediment yield in the watershed.The aims of this study are to explore the characteristics of land use dynamic change and soil conservation effect in different management stages of Zhifanggou small watershed,and to provide scientific support for the improvement of ecological service function in the Loess Plateau.[Methods]Based on the CSLE model,the spatial and temporal characteristics of land use change and soil conservation effect in the five management periods of the Zhifanggou watershed in the past 80 years were systematically evaluated.[Results](1)Before the vegetation destruction in 1938,the forestland and grassland in the watershed accounted for 88.55％.In 1958,the proportion of forest and grass vegetation decreased by only 32％.In 1978,the land use change was gentle.After the implementation of comprehensive management of small watersheds,the proportion of forest and grass vegetation in 1999 and 2020 was 64.73％and 86.55％,respectively.The proportion of forest and grass vegetation in 2020 was basically the same as that before the destruction in 1938,but the proportion of forestland was still slightly smaller.(2)The amount of soil conservation in the five periods of the watershed was 2.485 ×105 t,1.886× 105 t,2.288 ×105 t,2.362 ×105 t and 2.460 × 105 t,respectively.The amount of soil conservation decreased after vegetation destruction,and the amount of soil conservation increased after comprehensive management of small watersheds.Because the area of forestland was still lower than that before destruction,the amount of soil conservation in 2020 was still lower than 0.01％in 1938.(3)Driven by land transfer,the soil conservation of woodland,grassland and cultivated land in different periods increased or decreased by-99.80％～-17.86％,23.90％～69.18％and-25.06％～664.66％,respectively,compared with that in 1938.[Conclusions]The vegetation coverage of Zhifanggou watershed has been basically restored to the level before the destruction in 1938,indicating that the ecological restoration of the Loess Plateau has achieved remarkable results in Zhifanggou.