【摘要】 【目的】对福建省将乐县土壤侵蚀及保持量现状进行定量分析,为该地区制定森林经营方案及水土保持工作提供依据。【方法】以福建省将乐县为研究区,首先建立降雨侵蚀力因子(R)图层、土壤可蚀性因子(K)图层、坡长坡度因子(LS)图层,然后依据实际土地覆盖类型和植被覆盖度构建植被覆盖或作物管理因子(C)图层和水土保持措施因子(P)图层。基于地理信息系统(GIS)和修正的土壤通用侵蚀方程(RUSLE)估算土壤侵蚀量和保持量,定量分析坡度(0°,90°)、土地覆盖类型与土壤侵蚀强度之间的相关关系。【结果】2015年研究区的现实侵蚀量为42.64×10~4t/年,平均土壤侵蚀模数为189.07t/(km~2·年)。从6种土壤侵蚀类型来看,微度侵蚀面积占研究区总面积的88.31%,轻度侵蚀面积占10.36%,中度侵蚀面积占1.13%,这3种侵蚀类型的侵蚀量占侵蚀总量的比例分别为12.43%,60.44%和19.79%;强度、极强度、剧烈侵蚀面积及侵蚀量所占比例均较小。各侵蚀等级在研究区内的空间分布较为均匀,总体来说中部、北部地区侵蚀量较大。7个坡度带中,土壤侵蚀量所占比例较大的是[15°,25°)、[8°,15°)和[25°,35°)坡度带,其面积所占比例分别为35.63%,23.95%和17.53%,侵蚀量所占比例分别为44.68%,24.63%和20.90%。研究区年均土壤保持量为6.98×10~6 t,每km~2土壤保持量为3 099.36t/年;有林地和稀疏植被的每km~2土壤保持量均较高,分别为3 773.58和22 254.39t/年,明显高于其他土地覆盖类型。【结论】将乐县微度侵蚀面积所占比例最大,轻度侵蚀的侵蚀量所占比例最大;森林和稀疏植被对将乐县的土壤保持量贡献最大,进行皆伐作业设计时应该尽量减小皆伐面积。更多还原

【Abstract】 【Objective】This study quantitatively analyzed soil erosion and conservation in Jiangle,Fujian to provide basis for making forest management plan and soil and water conservation work in the region.【Method】The soil erosion and conservation condition in Jiangle,Fujian were evaluated by geographical information system(GIS)and the revised universal soil loss equation(RUSLE).The rainfall erosivity factor(R)layer,soil erodibility factor(K)layer and slope length factor(LS)layer were set up,and the vegetation cover or crop management factor(C)layer and soil and water conservation factor(P)layer were constructed according to actual land cover type and vegetation coverage.The relationship between land cover types,slope gradient and soil erosion was also quantitatively analyzed.【Result】The total of real soil losses in Jiangle was 42.64×10~4 t/a and average soil erosion was 189.07 t/(km~2·a).Among the 6 erosion types,micro erosion area occupied 88.31% of the total area,light erosion area occupied 10.36%,medium erosion area only occupied 1.13%,and the ratios of the three types to total erosion area were 12.43%,60.44% and 19.79%,respectively.The ratios of intensive,extremely intensive,and severe erosion as well as total erosion amount were relatively small.The spatial distribution of erosion grades was relatively uniform,and the erosion amounts were larger in central and northern regions.Among the seven slope belts,the [15°,25°),[8°,15°)and [25°,35°)belts accounted for large erosion ratios of 35.63%,23.95%and 17.53% of the total study area and 44.68%,24.63% and 20.90% of total soil erosion amounts.The annual average of soil conservation of the total study area was 6.98×10~6 t,and the soil conservation amount per km~2 was 3 099.36 t/a.The soil conservation amount per km~2 of forest land and sparse vegetation were 3 773.58 and 22 254.39 t/a,which were significantly higher than other land cover types.【Conclusion】The micro erosion area had the largest ratio in Jiangle,and the percentage of light erosion was the largest.Forest and sparse vegetation contributed most to soil conservation in Jiangle,and the clear-cutting area should be minimized.更多还原