贵州省土壤可蚀性K值空间分布特征及主要影响因子

Spatial Distribution Characteristics and Main Influencing Factors of Soil Erodibility K Values in Guizhou Province

为揭示贵州省土壤对侵蚀的敏感程度,阐明贵州省土壤可蚀性的空间分布特征,利用全国第二次土壤调查数据及《贵州土种志》,采用EPIC(Erosion-productivity impact calculator)模型计算贵州省全省土壤可蚀性K值,在ArcGIS中运用克里金插值法,对贵州省土壤可蚀性K值进行了空间插值,探究了土壤可蚀性的变化规律及空间分布特征,并重点分析成土母质、海拔和土地利用方式等对K值的影响关系。结果表明:(1)贵州省各土壤类型表层土的平均K值介于0.0230~0.0477 t·hm^(2)·h/(MJ·mm·hm^(2)),其中红黏土的K值最大,为0.0477 t·hm^(2)·h/(MJ·mm·hm^(2)),其次是潮土为0.0460 t·hm^(2)·h/(MJ·mm·hm^(2)),新积土的K值最小,为0.0230 t·hm^(2)·h/(MJ·mm·hm^(2));(2)全省以中低和中可蚀性土壤为主,土壤可蚀性值较高,土壤侵蚀风险大;(3)全省K值分布的空间差异性较大,从西向东逐渐增加,呈黔东>黔中部>黔西的变化趋势,南北方向上呈黔北南部>黔中>黔北北部>黔南的变化趋势;(4)各类成土母质形成土壤的可蚀性值介于0.0284~0.0468 t·hm^(2)·h/(MJ·mm·hm^(2)),页岩发育形成土壤的K值都较大(黄棕壤除外),砂岩发育形成土壤的K值较小;(5)随着海拔的升高,土壤可蚀性K值总体上呈现出降低的趋势;(6)土地利用方式对K值有明显的影响,其土壤可蚀性值大小依次为水田>旱地>草地>灌木>林地。研究结果较好地显示了贵州省土壤可蚀性K值的空间分布特征及主要的影响因素,可为贵州省土壤流失预报、水土保持普查等提供参考。

In order to reveal the sensitivity of soil to erosion and clarify the spatial distribution characteristics of soil erodibility in Guizhou Province,based on the data of the Second National Soil Survey and soil type records of Guizhou,the soil erodibility K values of Guizhou Province were calculated by EPIC(erosion productivity impact calculator)model,and the soil erodibility K values of Guizhou Province were spatially interpolated by Kriging interpolation method in ArcGIS,so as to explore the change pattern and spatial distribution characteristics of soil erodibility,the influences of soil parent material,altitude and land use mode on K values were analyzed.The results show that:(1)the average K values of topsoils of various soil types in Guizhou Province ranged from 0.0230 to 0.0477 t·hm^(2)·h/(MJ·mm·hm^(2)),among which the K value of red clay was the largest,was 0.0477 t·hm^(2)·h/(MJ·mm·hm^(2)),followed by tidal soil,which was 0.0460 t·hm^(2)·h/(MJ·mm·hm^(2)),and the K value of newly deposited soil was the smallest,which was 0.0230 t·hm^(2)·h/(MJ·mm·hm^(2));(2)low and medium erodible soils were main soil types in Guizhou Province,and the whole province was with high soil erodibility K values and high potential soil erosion risks;(3)the spatial difference of K value distribution in the whole province was large,which gradually increases from west to east,showing a change trend:east Guizhou>Central Guizhou>west Guizhou,and a change trend:south of northern Guizhou>central Guizhou>north of northern Guizhou>south Guizhou in the north-south direction;(4)the erodibility K values of soils formed by various soil forming parent materials were between 0.0284~0.0468 t·hm^(2)·h/(MJ·mm·hm^(2));the K value of soil formed by shale development is large(except for yellow brown soil),and the K value of soil formed by sandstone development was small;(5)with the increase of altitude,the soil erodibility value generally showed a downward trend;(6)land use mode had a significant impact on K value,and the soil erodibility K value deceased in the order:paddy field>dry land>grassland>shrub>forestland.The results show the spatial distribution characteristics and main influencing factors of soil erodibility K values in Guizhou Province,which can provide reference for soil loss prediction and soil and water conservation survey in Guizhou Province.