城镇化人为扰动下垫面类型影响水源涵养功能的评价

发布时间：2018-03-22 06:28

本文选题：土壤　切入点：水　出处：《农业工程学报》2017年22期 　论文类型：期刊论文

【摘要】：城镇化引起的各种人为扰动地貌单元的水源涵养功能较原地貌明显降低是造成城市水土流失的主要原因,在降雨和排水管网设计能力一定条件下,也是加剧城市内涝的主要原因。该文采用野外调查、室内物理分析及AHP(analytic hierarchy process)层次分析综合评价法,系统地分析了各种人为地貌单元的物质组成和持水性能变化并综合评价了其对原地貌水源涵养功能的影响特征。结果表明:1)各种扰动地貌单元2 mm土体颗粒质量分数在45%以上,原地貌2 mm土壤颗粒质量分数在92%以上;扰动地貌不均匀系数和曲率系数分别在11.05~41.30和0.32~3.15之间变化,其中不均匀系数较原地貌减小了4.51%~80.27%;各种扰动地貌单元土壤容重为施工便道(1.74 g/cm3)边坡绿化带(1.54 g/cm3)1 a弃渣堆积体(1.48 g/cm3)2 a弃渣堆积体(1.34 g/cm3)3 a弃渣堆积体(1.31 g/cm3),比坡耕地依次增加33.85%、18.46%、13.85%、3.08%和0.77%;扰动地貌的土壤总孔隙度、土壤田间持水量和饱和含水量则表现出相反趋势。2)人为扰动地貌单元土壤入渗性能总体小于原地貌单元,而原地貌土壤稳定入渗率则在2.83~6.22 mm/min之间变化;当项目区林地转化为新弃渣堆积体时对降雨和城市洪水动态调节功能影响最大,转化为施工便道时影响最小;人为扰动地貌单元土壤水库总库容、兴利库容和滞洪库容总体低于原地貌,当项目区草地转化为施工便道时对土壤持水能力及调蓄地表径流能力危害最大。3)各种扰动地貌单元水源涵养能力明显小于原地貌单元,以施工便道(0.421)最差,林地最好(0.651);在城镇化过程中应重视城镇水面、林草地的空间分布及占地面积,对短期松散堆积体也最好进行临时绿化措施。4)加强对扰动地貌物质组成、大孔隙结构和降雨-径流-入渗连续性定位研究,同时关注各扰动地貌在不同压实条件下土壤水库蓄水性能对项目区雨洪过程线和排水系统的影响。研究结果可为城市水土保持生态服务功能恢复、城市绿化带建设和洪水内涝缓解提供科学依据。
[Abstract]:The water conservation function of various man-made disturbed geomorphological units caused by urbanization is obviously lower than that of the original geomorphology, which is the main cause of urban soil erosion. Under certain conditions of rainfall and drainage network design ability, This paper adopts field investigation, indoor physical analysis and AHP(analytic hierarchy process-AHP comprehensive evaluation method. The changes of material composition and water holding capacity of various artificial geomorphological units are systematically analyzed and their effects on the original geomorphological water conservation function are comprehensively evaluated. The results show that the particle mass fraction of 2 mm soil mass in various disturbed geomorphologic units is more than 45%. The soil particle mass fraction of the original geomorphology 2 mm is more than 92%, the uneven coefficient and curvature coefficient of disturbed geomorphology vary between 11.05 ~ 41.30 and 0.32 ~ 3.15, respectively. The coefficient of inhomogeneity is 4.51% lower than that of the original geomorphology, and the soil bulk density of various disturbed geomorphologic units is 1.74 g / cm ~ (3)) slope green belt (1.54 g/cm3)1 a) / 1.48 g/cm3)2 a / 1. 34 g/cm3)3 a / 1. 31 g / cm ~ (3) C ~ (3), compared with sloping farmland, where the soil bulk density of various disturbed geomorphologic units is 1.74 g / cm ~ (3). The soil porosity of disturbed landforms was increased by 33.85%, 18.46%, 13.85% and 0.77%, respectively. The soil infiltration performance of artificial disturbed geomorphologic unit was smaller than that of the original geomorphologic unit, while the stable infiltration rate of the original geomorphic soil varied from 2.83 to 6.22 mm/min. When the forest land in the project area is transformed into a new sediment deposit, it has the greatest influence on the dynamic regulation function of rainfall and urban flood, and the least effect on the construction sidewalk, and the total reservoir capacity of soil reservoir is disturbed by human disturbance geomorphology unit. The capacity of Xingli reservoir and flood detention reservoir is lower than that of the original geomorphology, and when the grassland in the project area is converted into a construction sideway, the water holding capacity of soil and the ability of regulating surface runoff are most harmful. 3) the water conservation capacity of various disturbed geomorphological units is obviously smaller than that of the original geomorphologic unit. In the course of urbanization, attention should be paid to the urban water surface, the spatial distribution of forest and grassland and the area of land occupied, and the temporary greening measures. 4) to strengthen the composition of disturbed landforms. Study on Macropore structure and continuous location of Rain, runoff and infiltration, At the same time, the effects of the soil reservoir water storage performance on the rainfall and flood process and drainage system in the project area under different compaction conditions are concerned. The results can be used to restore the ecological service function of urban soil and water conservation. The construction of urban green belt and flood and waterlogging mitigation provide scientific basis.
【作者单位】：西南大学资源环境学院;重庆市水土保持生态环境监测总站;贵州大学林学院;辽宁工程技术大学环境科学与工程学院;
【基金】：重庆市水利局科技项目“都市功能区水土保持措施体系研究”,“生产建设项目水土流失危害研究”
【分类号】：S157

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