基于直方图匹配的东北漫川漫岗区粗分辨率坡度转换研究  

Conversion of Low-resolution Slope Gradient Based on Histogram Matching at Rolling Hilly Area of Northeast China

作　　者：赵婷 毋冰龙 郑粉莉[1,2] 赵录友 Zhao Ting;Wu Binglong;Zheng Fenli;Zhao Luyou(Institute of Soil and Water Conservation,Northwest A&F University,Yangling,Shaanxi 712100,China;The Research Center of Soil and Water Conservation and Ecological Environment,Chinese Academy of Sciences and Ministry of Education,Yangling,Shaanxi 712100,China)

机构地区：[1]西北农林科技大学水土保持研究所,陕西杨凌712100 [2]中国科学院教育部水土保持与生态环境研究中心,陕西杨凌712100

出　　处：《水土保持通报》2024年第6期149-158,共10页Bulletin of Soil and Water Conservation

基　　金：国家自然科学基金面上项目“典型黑土区地表径流、壤中流和土壤管道流驱动的浅沟侵蚀过程机制”(42177326);中国科学院A类战略性先导科技专项子课题“典型黑土区风力—水力—冻融驱动的复合侵蚀过程与阻控关键技术”(XDA28010201)。

摘　　要：[目的]为了克服目前可免费下载的30 m分辨率DEM在提取东北漫川漫岗地貌区耕地坡度时存在的坡度变缓问题,获取精确坡度数据,为东北漫川漫岗地貌类型区土壤侵蚀定量评价提供重要数据支持。[方法]基于无人机航测影像生成5 cm分辨率DEM并对其重采样获得1,5和12.5 m分辨率的DEM,结合免费下载的30 m分辨率DEM,确定研究区DEM提取坡度的最佳分辨率;基于直方图匹配算法,分坡度段拟合了30 m与最佳分辨率DEM之间的坡度转换模型。[结果]①5组DEM分辨率提取的坡度信息表明,1和5 m与5 cm分辨率DEM提取的坡度分布频率具有较强的相似性,且5 m分辨率DEM与1∶10000比例尺地形图的分辨率相对应。据此确定5 m分辨率为构建坡度转换模型的最佳分辨率。②基于直方图匹配算法分坡度段构建了30与5 m分辨率DEM提取坡度的一元一次线性模型和一元二次非线性模型;且当地面坡度小于7°时宜选取线性坡度转换模型,而当地面坡度大于7°时宜选取非线性坡度转换模型。③经线性和非线性坡度转换模型优化后,30 m坡度分布频率与5 m分辨率的坡度分布频率基本相似,且协方差、相关系数均大幅度提高。这说明30 m分辨率DEM提取的坡度信息经模型转换后能够真实反映地面起伏特征,且非线性坡度转换模型优化效果更佳。[结论]5 m分辨率为研究区DEM提取坡度的最佳分辨率。构建的低—高分辨率的坡度转换模型中,非线性坡度转换模型较线性坡度转换模型的优化效果更好。[Objective]Slope gradient data was accurately obtained to address the limitation of slope gradient underestimation using the freely downloaded 30 m resolution digital elevation model(DEM)for farmland in Northeast China,in order to provide important data support for quantitatively evaluating soil erosion in the rolling hilly regions.[Methods]A 5 cm resolution DEM was generated from drone survey images and resampled to obtain 1,5,and 12.5 m DEM resolutions.Combined with the 30 m DEM resolution,the optimal DEM resolution for slope gradient extraction in the study area was identified.Additionally,the histogram matching method was used to establish a slope gradient conversion model between the 30 m DEM resolution and the optimal DEM resolution for each slope gradient category.[Results]①The slope gradient distributions derived from the five DEM resolutions indicated that the 1 m and 5 m DEM resolutions exhibited a strong similarity to the slope gradient distribution of the 5 cm DEM.Given that the 5 m DEM resolution corresponds to a 1∶10,000 scale topographic map,the 5 m DEM resolution was optimal for constructing the slope gradient conversion model.②Using the histogram matching method,a univariate linear model and a univariate quadratic non-linear model were developed for slope gradient conversion between the 30 m and 5 m DEM resolutions across different slope gradient segments.The linear conversion model was suitable for slopes less than 7°,while the non-linear model was more appropriate for slopes greater than 7°.③After applying both linear and non-linear conversion models,the frequency distribution of slope gradients extracted from the 30 m DEM resolution closely matched that of the 5 m DEM resolution,significantly improving covariance and correlation coefficients.This reflected that the slope gradients after conversion from the 30 m DEM resolution can accurately represent ground undulation;additionally,the optimization results from the non-linear conversion model were superior to those from the linear con

关 键 词：东北漫川漫岗区 不同分辨率DEM 直方图匹配法 坡度转换模型 

分 类 号：S157.1[农业科学—土壤学] P231[农业科学—农业基础科学]