窟野河流域土壤侵蚀时空特征及趋势预测

Spatio-temporal Pattern and Trend Prediction of Soil Erosion in Kuye River Basin

[目的]窟野河流域是黄河中游粗沙区的主要侵蚀策源地。阐明窟野河流域土壤侵蚀时空变化特征,预测流域土壤侵蚀发展趋势,为流域未来水土流失综合治理提供决策支持。[方法]基于窟野河流域2010-2020年多源数据,刻画流域土壤侵蚀空间分布,结合土壤侵蚀强度动态度、信息熵、综合指数和转移矩阵等定量指标,分析土壤侵蚀强度变化特征;构建CA-Markov模型,预测流域2025年土壤侵蚀状况。[结果](1)研究区土壤侵蚀以微度、轻度侵蚀为主,面积占比超过70%,较强度侵蚀主要分布于流域中下游和支流悖牛川区域。2010-2020年,平均土壤侵蚀量由1955.56 t/(km^(2)·a)降至892.98 t/(km^(2)·a),微度侵蚀面积大幅增加,其他侵蚀等级面积相应减少,大部分区域土壤侵蚀强度不变或下降,仅有不到3%的区域侵蚀强度加剧。(2)窟野河流域土壤剧烈、极强度、强度侵蚀的动态度变化较大,土壤侵蚀强度信息熵由1.29稳定下降至0.81,土壤侵蚀强度综合指数由178.96降低至76.61,且前5年下降幅度更高,流域土壤侵蚀强度朝减弱方向转化,主要发生在邻近两侵蚀强度等级之间。(3)CA-Markov模拟显示,预计到2025年,流域土壤侵蚀状况将进一步改善,微度侵蚀占比超75%。[结论]2010-2020年间,研究区土壤侵蚀状况持续好转,后5年水土流失治理效率更高,2025年流域土壤侵蚀状况将进一步改善。

[Objective]Kuye River Basin is the main source of erosion in the coarse sand area in the middle reaches of the Yellow River.The study is aimed at elucidating the spatio-temporal pattern of soil erosion,predicting the development trend of soil erosion in Kuye River Basin and providing decision support for the comprehensive control of soil erosion in the future.[Methods]Based on the multi-source data from 2010 to 2020,the spatial distribution of soil erosion in the Kuye River Basin was studied,and the characteristics of soil erosion intensity change were analyzed by using quantitative indicators such as dynamic degree of soil erosion intensity,information entropy of soil erosion intensity,comprehensive index of soil erosion intensity and transfer matrix.The CA-Markov model was established to predict the soil erosion in 2025.[Results](1)The soil erosion intensity in the study area was mainly in micro and mild erosion,accounting for more than 70%of the total area,and stronger erosion was mainly distributed in the middle and lower reaches of the basin and tributary Beiniuchuan.From 2010 to 2020,the average soil erosion decreased from 1955.56 t/(km^(2)·a)to 892.98 t/(km^(2)·a),the area of micro erosion increased significantly,and the area of other erosion intensity decreased correspondingly.The soil erosion intensity remained unchanged or decreased in most regions,and only less than 3%of the regions experienced increased erosion intensity.(2)The dynamic degree of intensity,extreme intensity and extreme erosion in Kuye River Basin changed greatly,the information entropy of soil erosion intensity decreased steadily from 1.29 to 0.81,the comprehensive index of soil erosion intensity decreased from 178.96 to 76.61 and the decline rate was higher in the first five years,and the change of soil erosion intensity in the basin to the weakening direction mainly occurred between the two adjacent erosion intensity levels.(3)CA-Markov model simulation shows that,it is expected that by 2025,the soil erosion situation in the basin will be further improved,with the proportion of micro erosion accounted more than 75%.[Conclusion]From 2010 to 2020,the soil erosion situation in the study area continued to improve,and the control efficiency of soil erosion in the next five years was higher,and the soil erosion situation in the basin would be further improved in 2025.