| 摘要: |
| 【目的】采用空间插值法和地图代数法对土壤水蚀速率进行定量评价和制图，比较2种方法计算结果的异同，以期为不同区域土壤侵蚀定量评价和制图提供参考。【方法】以青藏高原典型样区为例，以现有土壤侵蚀因子数据和抽样调查单元数据为数据源，采用基于侵蚀因子栅格图层的地图代数法和基于抽样调查单元的空间插值法2种方法计算研究区土壤水蚀速率并制图，对计算结果差异进行对比分析。【结果】在青藏高原典型样区，采用地图代数法和空间插值法2种方法计算的土壤水蚀速率分别为549.4和593.5 t/（km2·年），二者结果较为接近，表明2种方法计算结果均能反映研究区土壤侵蚀基本状况。采用2种方法计算的研究区土壤水蚀速率的宏观分布趋势相同，即由北向南研究区土壤水蚀呈逐渐增强的趋势，且与实际情况相符。基于空间插值法的土壤水蚀速率表面特征图较为平滑，能比较真实地反映土壤侵蚀情况；基于地图代数法的土壤水蚀速率表面特征图较为粗糙，但能较好地反映局部土壤侵蚀变异情况。当土壤水蚀速率为>250~3 000 t/（km2·年）时，空间插值法计算的各等级土壤侵蚀面积比例均高于地图代数法；当土壤水蚀速率≤250 t/（km2·年）或者＞3 000 t/（km2·年）时，地图代数法计算的各等级土壤侵蚀面积比例均明显高于空间插值法，说明空间插值法的结果更突出中间土壤侵蚀强度级别，而地图代数法的结果更突出较小和较大土壤侵蚀强度级别。【结论】地图代数法和空间插值法均可用于不同区域土壤侵蚀定量评价与制图，其中空间插值结果能更好地反映研究区的平均土壤侵蚀状况，故在青藏高原典型样区可优先选择空间插值法。 |
| 关键词: 空间插值法 地图代数法 土壤水蚀速率 抽样单元 青藏高原 |
| DOI： |
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| 基金项目:中国科学院战略性先导科技专项子课题“土壤侵蚀定量评价与分区防控对策”（XDA20040202） |
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| Comparison of two soil erosion assessment and mapping methods in typical sample areas of the Tibetan Plateau |
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DU Chaozheng,YANG Qinke,WANG Chunmei,et al
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| Abstract: |
| 【Objective】Two methods of spatial interpolation and map algebra were used to assess water erosion rate of soil in the study area and their similarities and differences were compared to provide a reference for quantitative assessment and mapping of regional soil erosion.【Method】Map algebra method based on erosion factor grid layer and spatial interpolation method based on sampling survey unit were used to calculate water erosion rate of soil in the study area using GIS,and the results were compared.【Result】In the typical sample areas of the Tibetan Plateau,the soil water erosion rates calculated by map algebra method and spatial interpolation method were 549.4 and 593.5 t/(km2·a) respectively.The results were relatively close,indicating that both methods could reflect the basic situation of soil erosion.The calculated macroscopic distribution trends were also same with a gradually increasing trend from north to south,which was consistent with actual situation.The surface characteristic map of soil water erosion rate based on spatial interpolation method was smoother and could better reflect soil erosion.Although the surface characteristic map based on map algebra method was rough,it could better reflect local variations of soil erosion.When the soil water erosion rate was 250-3 000 t/(km2·a),the proportion of soil erosion area of each grade calculated by spatial interpolation method was higher than that by map algebra method.When soil water erosion rate was ≤ 250 t/(km2·a) or > 3 000 t/(km2·a),the proportion of soil erosion area of each grade calculated by map algebra method was significantly higher than that by spatial interpolation method.The spatial interpolation method was more prominent in middle soil erosion intensity level,while the map algebra method was more prominent in smaller and larger soil erosion intensity levels.【Conclusion】Both methods could be used for quantitative assessment of regional soil erosion.In the typical sample areas of Tibet Plateau,the spatial interpolation method was preferred and it could better reflect average erosion situation. |
| Key words: spatial interpolation map algebra soil water erosion rate sampling unit Tibetan Plateau |
