| This paper analyzes the temporal and spatial distribution of grassland soil erosion in the middle section of the northern slope of Tianshan Mountains,predicts the changing trend of soil erosion under different climate scenarios in the future and the image factors of soil erosion,and provides theoretical basis and practical reference for soil and water conservation and ecological environment restoration in the middle section of the northern slope of Tianshan Mountains.The study took the grassland in the middle section of the northern slope of the Tianshan Mountains as the target area,and adopted the methods of field sampling,geographic information system technology,remote sensing inversion and model simulation,and integrated the Chinese Soil Loss Equation（CSLE）and the ecosystem process model（Biome-BGC model）,quantitatively analyzed the temporal and spatial distribution characteristics of soil erosion from2000 to 2019,clarified the spatial differentiation of soil erosion,and predicted the change trend of soil erosion from 2019 to 2050 under different Representative Concentration Pathways（RCPs）,to explore the influencing factors of soil erosion in mountain grasslands.Research indicates:（1）From 2000 to 2019,the average soil erosion in the middle section of the northern slope of the Tianshan Mountains was 29.24(t·hm-2·y-1),showing an overall upward trend with a rising rate of0.741/year,and its key factor,the average rainfall erosivity,was 321.9(MJ·mm·hm-2·h-1·y-1),and showed a slow upward trend with a rate of 2.74/year.From 2000 to 2019,the average biological measure factor value of the northern slope of the Tianshan Mountains was 0.24,showing a slow downward trend with a rate of 0.0025/year.In terms of space,the soil erosion modulus of grassland in the middle section of the northern slope of Tianshan Mountains from 2000 to 2019 is summer pasture(39.29 t·hm-2·y-1)>winter pasture(26.15 t·hm-2·y-1)>spring and autumn pasture(17.96 t·hm-2·y-1).The average rainfall erosivity is summer pasture(338.5 MJ·mm·hm-2·h-1·y-1)>winter pasture(329.08 MJ·mm·hm-2·h-1·y-1)>spring and autumn pasture(294.98 MJ·mm·hm-2·h-1·y-1);the biological measure factor value was spring and autumn pastures（0.59）>summer pastures（0.38）>winter pastures（0.29）.（2）Under the RCP2.6 and RCP4.5 scenarios,the average soil erosion modulus in the middle section of the northern slope of the Tianshan Mountains from 2030 to 2050 has a significant decline compared with 2019,with a decline rate of 52.6%and 72.4%,respectively.RCP2.6 Compared with the RCP4.5scenario,the average soil erosion modulus from 2030 to 2050 was 7.62(t·hm-2·y-1)higher in the scenario,and the proportion of soil erosion area was roughly similar.Compared with 2019,the overall rainfall erosivity from 2030 to 2050 under the RCP2.6 and RCP4.5 scenarios decreased by 13.77(MJ·mm·hm-2·h-1·y-1)and 69.25(MJ·mm·hm-2·h-1·y-1);under the RCP2.6 and RCP4.5 scenarios,the ANPP of the entire study area in 2030-2050 showed a trend of first increasing and then decreasing,and under the RCP2.6 and RCP4.5 scenarios 2030-2050 Compared with 2019,the annual ANPP decreased by18.13(g C m-2y-1)and 23.37(g C m-2y-1)respectively.（3）The results of the driving ability of soil erosion influencing factors to the spatial differentiation of soil erosion in the whole area of the northern slope of the Tianshan Mountains are ranked in descending order:vegetation coverage（0.239）>slope（0.149）>slope length（0.063）>rainfall（0.047）>Soil attribute（0.018）;under the RCP2.6 scenario,the decrease of rainfall mainly aggravates the soil erosion,and the increase of the vegetation mainly plays the mitigation effect.The key soil erosion prevention areas are mainly distributed in the eastern part of Dabancheng and the southern part of Urumqi County in the seasonal pasture range,and the relationship between soil erosion sensitivity zones and soil erosion status is good. |
PDF Full Text Request