摘要
容许土壤流失量是评价区域水土流失和生态环境状况的基础依据,分析其特征对指导区域水土流失防治和生态环境建设具有重要的现实意义。本文将通过土地生产力指数模型和土层厚度计算得到的北京主要土属的容许土壤流失量,按照面积加权平均得到亚类和土类的容许土壤流失量,对他们进行嵌套方差分析和多重比较,并以亚类为制图单元制作了北京市容许土壤流失量空间分布图。北京大面积土壤的容许土壤流失量低于150 t/(km2·a),主要土属的容许土壤流失量介于50~313 t/(km2·a)之间,按面积加权平均为194 t/(km2·a)。北京市土类间容许土壤流失量差异不显著,亚类间容许土壤流失量差异显著。粗骨类土壤的容许土壤流失量较低,全部低于100 t/(km2·a),说明形成过程中经历了较强烈的水土流失,细粒物质大多已被侵蚀,土体中残留的粗骨碎屑物较多,土层浅薄,土壤肥力低;山地类土壤正发生着较强的侵蚀,随着土壤侵蚀强度增大,容许土壤流失量降低。北京市西部、北部和东北部山区的容许土壤流失量较低,一般低于150 t/(km2·a);东南部平原区的容许土壤流失量较高,一般高于150 t/(km2·a)。北京市在土类级别反映不出不同土壤类型间容许土壤流失量的差异,而土壤亚类级别可以反映出容许土壤流失量在土壤类型上的差异。如果以土属级别为制图单元,由于土属数量较大、图斑分布零散,不便于使用和管理。因此,使用亚类级别为制图单元,制作北京市容许土壤流失量图,是较好的选择。
[Background]Soil loss tolerances is a fundamental basis for accessing soil loss and ecological conditions,thus analyzing its characteristics plays an important role in practice for providing a guidance to local prevention and control of soil erosion and ecological construction.Current soil loss tolerances are for large regions and they are too general to reflect the detailed variation in soil erosion within projects for soil erosion and water loss control.This study analyzes the characteristics of soil loss tolerance distribution in Beijing,providing data for setting proper soil tolerances and supporting soil and water conservation management in different districts.[Methods]Soil loss tolerances of soil genus in Beijing were calculated by the productivity index model and soil thickness.The values of soil subgroups and groups were then obtained by an area weighted method according to those of soil genus and these values were analyzed and compared by nested variance analysis and multiple comparisons.Finally,a distribution map of the soil loss tolerance in Beijing was made by the values for soil subgroups which acted as the mapping unit.[Results]In Beijing,the soil loss tolerance of main soil genus were between 50-313 t/(km2·a)with an area weighted mean of 194 t/(km2·a).In most parts of Beijing,these values were<150 t/(km2·a),53.4%of the total area were in the range of 100-150 t/(km2·a)and 23.8%were in the range of 50-100 t/(km2·a).These obtained soil loss tolerances of soil subgroups were significantly different while those of soil groups were not significantly different.The soil loss tolerance of skeletal soils(<100 t/(km2·a))were lower than others.It indicated that these soils had been severely eroded by washing off fine particles during the formation process,only remaining a thin layer of coarse fragments with low fertility.Mountain soils were suffering severe erosion,and the soil loss tolerance became lower with the increase of erosion intensity.The soil loss tolerance values were<150 t/(km2·a)in the mountain area in west,north,and northeast of Beijing,while they were>150 t/(km2·a)in the plain area in the southeast.[Conculsions]The difference among soil loss tolerance cannot be shown in the soil group level but it is clear in the soil subgroup level.Although the soil loss tolerances in soil genera level are more detailed,it is not easy to use and manage the scattered patches on the map because of their great number.Therefore,it is optimal to select the values in subgroup level as the mapping unit to make soil loss tolerance distribution map in Beijing.
作者
王志刚
王家乐
韩培
刘洪鹄
杨坤
张超
张平仓
WANG Zhigang;WANG Jiale;HAN Pei;LIU Honghu;YANG Kun;ZHANG Chao;ZHANG Pingcang(Changjiang River Scientific Research Institute, 430010, Wuhan, China;Center for Mountain Torrent and Geological Disaster Prevention, Ministry of Water Resources, 430010, Wuhan, China;Beijing General Working Station of Soil and Water Conservation, 100036, Beijing, China)
出处
《中国水土保持科学》
CSCD
北大核心
2020年第5期89-95,共7页
Science of Soil and Water Conservation
基金
水利科技示范项目“基于无人机影像的重大水利工程水土保持监管技术示范”(SF-201709)
北京市水土保持工作总站项目“《北京市水土保持条例》配套制度-北京市容许土壤流失量标准”
深圳市典型水土保持植物配置模式对消减城市面源污染的功能研究项目(CKSK2017819/TB)
深圳市典型区水土保持措施生态优化技术研究项目(CKSK2017820/TB)
2019年武汉市水土流失动态监测与生产建设项目监管项目(CKSK2019444/TB)。
关键词
容许土壤流失量
土壤流失控制值
空间分布图
制图单元
soil loss tolerance
control values of soil loss
spatial distribution map
mapping unit