Supported by the Science and Technology Project of Chongqing Municipal Water Conservancy Bureau in China (No. 20130233)
城镇化过程中由于开挖、堆垫以及路面硬化等建设活动，造成各种扰动地貌单元，其中，弃土弃渣堆积体是城镇主要的绿化用地及城市绿地建设客土来源；扰动地貌与原地貌单元共同组成城镇建设项目区的复杂下垫面。采用野外和室内试验方法，系统地比较了城镇建设中不同地貌单元的物质组成、入渗和持水性能的差异性，并探讨了三种城市土壤重构类型及其减缓城市内涝的潜在作用。结果表明：（1）不同地貌单元土壤容重差异显著（p<0.05），施工便道（1.74 g cm-3）>2年弃渣堆积体（1.58 g cm-3）>2月弃渣堆积体（1.52 g cm-3）>荒草地（1.47 g cm-3）>坡耕地（1.34 g cm-3）>人工林地（1.32 g cm-3），弃渣堆积体平台处土壤容重均大于边坡处。（2）不同地貌单元土壤稳定入渗率均表现为弃渣堆积体边坡>原地貌>弃渣堆积体平台；弃渣堆积体平台处稳定入渗率大小主要受平台压实过程中可能存在的滞水层影响。（3）不同地貌单元的各种土壤水库特征中库容差异显著（p<0.05），扰动地貌单元的总库容（378.7 t hm-2）小于原地貌单元（472.6 t hm-2）；扰动地貌单元总库容表现为2年弃渣堆积体>2月弃渣堆积体>施工便道，原地貌单元则表现为人工林地>坡耕地>荒草地。（4）城市绿地土壤重构类型主要有乔木适生型土壤构型、灌木适生型土壤构型和草本适生型土壤构型，土层厚度、容重、<2 cm砾石含量和有机质是影响重构土壤质量的关键因素；重构土壤类型（草本适生型、乔木适生型、灌木适生型）可保证草本植物在定植后2个月、乔灌木在定植后4~5个月左右充分发挥其调控地表径流、缓解城市内涝的潜在作用。研究结果可为三峡库区城镇化建设中绿地建设和城市洪水调控提供科学依据。
【Objective】Urbanization absolutely needs activities like excavating, land-filling and road paving during its process, thus generating a variety of disturbed landform units, among which the dumping of waste soil is the main soil source supplying the construction of urban greenbelts with alien soil. Consequently, the distubered landform units join together with native landform units forming a complex underlying in the area of a urbanization construction project. 【Method】 In this paper, by means of field investigation and laboratory tests, a system comparison was made of the various landform units in material composition, water infiltration and water holding capacity, and then discussions were carried out on three types of reconstructed urban soil and their potential roles in mitigating the risk of urban water logging. 【Result】 Results show: (1) Soil bulk density differed significantly (p <0.05) between the landform units and varied in the order of Construction makeshift road (1.74 g cm-3) > 2-year piles of dumped waste soil (1.58 g cm-3) > 2-month piles of dumped waste soil (1.52 g cm-3) > Waste grassland (1.47 g cm-3)> Cultivated slopeing land (1.34 g cm-3) > Artificial forest land (1.32 g cm-3). In the piles of dumped waste soil, soil bulk density was higher on their flat tops than on their side slopes; (2) Soil infiltration rate varied in the order of side slopes of the piles of dumped waste soil > native landform > flat tops of the piles of dumped waste soil; stable infiltration rate on flat tops of the piles varied too with compactness of its surface layer, thus exposing it to the risk of forming of an aquitard; (3) Water storage capacity differed sharply from lanfform unit to landform unit (p<0.05), and was generally lower in reconstructed landform units (378.7 t hm-2) than native ones (472.6 t hm-2); it varied in the order of: 2-year piles > 2-month piles > Construction makeshift road, for disturbed landform units and in the order of Artificial forest land > Cultivated slopeland > Waste grassland for native landform units; and (4) For urban green land, soil reconstruction was usually done in three types, that is, tree-suitable, shrub-suitable and herb-suitable, and thickness bulk density, gravel content (<2 cm) and organic matter content were the main factors determining soil quality of the reconstructed soils. Soils reconstructed in line with the three types (herb-suitable, shrub-suitable and tree-suitable) may ensure the revegetation successful and capable of playing its potential role in regulating surface runoff and mitigating the risk of urban waterlogging, 2 months after plantation for herbs and 4~5 months for trees and shrubs. 【Conclusion】 All the findings in this study may provide certain scientific support for soil reconstruction for urban green belts and land and management of urban waterlogging during the process of urbanization in the Three-Gorge Reservoir Area.
娄义宝,史东梅,蒋 平,李叶鑫,林 姿,蒲 境.紫色丘陵区城镇化不同地貌单元的水文特征及土壤重构[J].土壤学报,2018,55(3):650-663. DOI:10.11766/trxb201712060504 LOU Yibao, SHI Dongmei, JIANG Ping, LI Yexin, LIN Zi, PU Jing. Hydrological Characteristics and Soil Reconstruction of Different Landform Units as Affected by Urbanization Process in Purple Hilly Area[J]. Acta Pedologica Sinica,2018,55(3):650-663.复制