黄丘区自然草地对坡面土壤入渗的影响机制

利用野外人工模拟降雨试验,研究了草地覆盖度变化对土壤入渗过程的影响,定量分析了草地作用下入渗参数的变化规律。结果表明:草地覆盖度对土壤入渗率的影响存在着分级现象,36%~54%覆盖度范围内入渗率随着覆盖度增大而增大的幅度并不大,只有当草地覆盖度超过59%之后,入渗率才明显增大;草地具有削减入渗波动的能力;Horton和Philip入渗公式均能有效地反映不同植被覆盖度下降水在土壤中的入渗过程及特性;草地覆盖能有效增大土壤初始入渗率和稳渗率,并且土壤初始入渗率以及稳渗率与草地覆盖度均可用指数函数关系表示;草地覆盖度越高,初始入渗率和稳渗率相差越小,入渗率衰减得越慢。     

黄土高原半干旱区雨水资源化研究综述

雨水资源化是黄土高原半干旱区发展农业生产、提高土地生产力的最佳选择。简述了雨水收集技术、雨水储存技术、雨水净化技术和雨水灌溉技术,分析了雨水利用对水土保持和区域生态环境的影响。在雨水资源评价中,除对雨水资源的总量进行评价外,更重要的是对可开发利用的雨水资源潜力进行合理评价,确定合理的开发量。     

The Effect of Geological Heterogeneity and Groundwater Table Depth on the Hydraulic Performance of Stormwater Infiltration Facilities

Urbanization has led to a substantial change in the hydrological cycle of urban catchments. Increased runoff and urban flooding, decreased direct subsurface infiltration and groundwater recharge, deterioration of water quality are among the major effects of this alteration. To alleviate these effects, Low Impact Development (LID) practices have been frequently adopted for stormwater management. Among LID infrastructures, infiltration facilities are particularly challenging to design and model due to the considerable amount of uncertainties related to the hydrogeological configuration of installation sites. To date, analysis on how soil heterogeneity, groundwater table depth, and thickness of the unsaturated zone affect the hydraulic performance of infiltration facilities are lacking. To address this knowledge gap, a series of numerical experiments under transient variably water saturated conditions were performed for a hypothetical infiltration facility. Numerical simulations showed that i) infiltration rates increase considerably as the initial depth of the groundwater table increases, ii) the contribution of the bottom of the facility to the infiltration of water is generally higher than the sides, iii) the presence of a less conducting soil layer at a short depth from the bottom of the facility reduces infiltration rates dramatically, iv) the complete clogging of the bottom of the facility has a dramatic impact on the hydraulic performance, v) the stochastic heterogeneity of the soil controls the overall stormwater infiltration process through the facility, and the hydraulic performance may largely deviate from the case when heterogeneity is absent.

     

黄土高原地区淤地坝运行管理调查研究

淤地坝是黄土高原地区重要的水土保持工程措施，在治理水土流失、改善生态环境、减少人黄泥沙等方面发挥了巨大的作用。黄土高原地区淤地坝的运行管理模式分为：集体管理型、承包型、租赁型、股份合作型、拍卖型、经济实体管理型和乡(镇)水土保持站统一管理型等。通过对多种运行管理模式的介绍与评价，提出了今后的运行管理建议为：①因地制宜，分类指导；②多渠道筹集管护资金，全面落实管护责任；③研究制定运行管理办法，健全管理制度；④做好政策调研，尽快出台优惠政策；⑤加大技术指导和技术服务力度等。     

不同泥沙级配浑水灌溉入渗量及减渗作用分析

浑水灌溉是黄河流域普遍存在的现象,浑水中泥沙级配和浓度的大小对土壤入渗过程有很大的影响,不同泥沙级配和浓度的浑水入渗结果有显著差异。通过分析不同泥沙级配浑水灌溉入渗试验数据,并与清水灌溉入渗试验对照得出:不同泥沙级配浑水灌溉累计入渗量与时间的关系和清水相同,均为指数为正的幂函数曲线。相同含沙量、同一入渗历时,泥沙较粗的浑水始终比泥沙较细的浑水累计入渗量大。泥沙颗粒越细的浑水,其相应的累计入渗量越小,减渗量和减渗率越大;而相同累计入渗量条件下,泥沙颗粒越细,相应入渗历时越长。不同泥沙级配浑水相对于清水的时段减渗量和减渗率随时间均先增大后减小,最大值均发生在前50 min,泥沙组成颗粒越细,最大值出现的时间越早,同时刻浑水的减渗作用越强。     

Soil Surface Roughness Effects on Infiltration Process of a Cultivated Slopes on the Loess Plateau of China

Infiltration is the only way water enters soil on the cultivated slopes of the China’s Loess Plateau, so infiltration plays an important role in conserving soil moisture. The objective of this study was to investigate how a soil wetting front created by simulated rainfall migrated in soil with different types of surface roughness. The three types of soil surface treatments studied included surfaces of smooth, medium rough and rough soil. The results showed that, 1) compared with a smooth surface texture, medium rough and rough surface textures have a higher infiltration capacity; 2) the infiltration rate gradually decreases as the wetting front deepens and the rate tends stabilize over time. This change could be described by a logarithmic function; 3) at the early stage of rainfall, the wetting front of medium rough and rough surface textures varied greatly, while the variability of the wetting front decreases markedly after the infiltration rate stabilizes; 4) with increasing depth of the wetting front, the similarity between the wetting front and soil surface profile decreased significantly for the medium rough and rough surface textures. These results indicate that the process of infiltration on cultivated slopes on the Loess Plateau changed from a non-uniform pattern to a uniform pattern as time passed during a rainfall event. Overall, soils with rougher soil surfaces experienced a larger effect of roughness on the process of infiltration.     

黄土地区地下渗滤系统脱氮除磷效果试验研究

对西北黄土地区地下渗滤系统处理生活污水的氮磷去除效果进行试验研究.结果表明:在2.4 cm/d的水力负荷下,系统对氨氮、总磷的去除率可达到95%以上,对COD的去除率可达到85%以上;系统熟化后出水中氨氮、COD、总磷分别低于1、30、0.3 mg/L;系统对总氮亦有良好的去除效果,达69.7%.在试验中,硝化效果良好但反硝化效果不够理想,表明在黄土地区,改善渗滤场条件以促进反硝化反应是提高地下渗滤系统总氮去除率的关键.     

Integrated Assessment of Water Resources Potential in the North China Region

Abstract

Potential assessment of water resources development (PAWRD) is very important for regional water management, water allocation, water transfer, and economic planning, especially for today's China, which is under a rapid economic growth, a continued expansion of population, and an increasingly deteriorating eco-environment. In this work, the southern part of Hathe River (SPHR) is selected as the representative area of the North China Region for a case study based on considerations such as available data, geographic characteristics, administrative boundaries, and the state of water shortage. A growth pattern of regional water resources development is presented. A fuzzy assessment model is established and applied to determine the growth stage, an indicator for water resources development potential. Seven assessment factors, selected based on the conditions of supply, demand, and use efficiency of water subjected to the regional physical, social, and economic settings, include irrigation rate of arable land, exploitation rate of water resources, the water-saving level, a water supply and demand modulus, the water supply per capita, and the ratio of eco-environmental water use. These factors are integrated into the fuzzy assessment model, which is shown to be capable and effective for potential assessment. The assessment results demonstrate the potential of water resources development is little in SPHR and are substantiated by the necessity of the middle route of the South-North Water Transfer (SNWT) in the long run. It is also suggested at present that promoting water saving and strengthening water demand controls would be the most feasible and effective solution to mitigate water shortage stress of SPHR before the SNWT scheme is implemented. PAWRD provides a scientific tool for water-demand management and water-saving improvement, as well as a necessary basis for decision-making for economy planning and water transfer design.     

西北地区水资源配置与管理的思考

在对西北地区水资源量和可利用量分析的基础上 ,结合目前西北地区的水资源开发利用情况 ,分析西北地区水资源还有相当的开源潜力 ;在对目前水资源开发利用中存在的生态问题、荒漠化问题、盐渍化问题以及水资源管理问题的调查研究的基础上 ,提出了西北地区水资源合理配置的基本思路和加强水资源管理的对策措施     

Comparing the Effects of Different Daily and Sub-Daily Downscaling Approaches on the Response of Urban Stormwater Collection Systems

Water Resources Management - Change in the spatiotemporal pattern of precipitation is one the most important effects of climate change. This may result in considerable changes in urban flooding and...     

三峡库区城镇移民安置区社区管理方式研究

三峡库区百万移民已搬迁安置完成近10年,在社会转型的新的历史背景下,库区城镇移民安置区社区管理方面也出现了新的问题,需要不断改革和创新管理方式。从健全移民安置区社区组织结构、推进移民安置区社区管理的社会化进程等入手,对改革和创新库区城镇移民安置区社区管理方式进行了研究和探讨,提出了一些有针对性的政策建议。     

Management Influences on Stream-Flow Variability in the Past and Under Potential Climate Change in a Central European Mining Region

Water Resources Management - Robust assessments of stream-flow volume and variability under current and potential future conditions are essential for sustainable water resources planning and...     

影响黄土丘陵区次降水泥沙输移比的水文要素

以桥沟小流域为研究对象,利用该流域不同地貌部位的野外径流场及沟道水文站网观测资料,计算了不同场次降水的泥沙输移比,较为系统地研究了影响桥沟流域次降水泥沙输移比的水文要素。结果表明:土壤前期含水量、流域的降水过程特征、洪峰流量、径流量、水流含沙量是影响次降水泥沙输移比的主要水文要素;提出了表示降水、径流、泥沙对泥沙输移比影响的表征参数,即降水峰现系数、径流侵蚀力和泥沙相对容重。     

西北地区水资源可利用量及承载能力分析

通过分析西北地区的水资源量，可利用量，人类生存发展对水资源的需求，提出了西北地区最大可支撑人口数量，对西北地区的水资源承载能力进行了评价。从评价结果来看，西北地区黄河流域，河西地区和新疆的东疆地区将出现人口超载，超载率分别达38％，10％，27％。超载的原因是水资源紧缺，在人口密度较大的区域水资源最为紧缺，人口和经济发展对水资源的需求超过了水资源的承载能力，解决人口超载的根本途径是节水和开源。     

Multi-Objective Optimal Design of Detention Tanks in the Urban Stormwater Drainage System: LID Implementation and Analysis

Under the influences of climate change and rapid urbanization, extreme rainfall events become more and more intensive and the urban flooding issues have been frequently faced in many cities in the world. Previous practical and scientific experiences have demonstrated that appropriate utilization of detention facilities and low impact development (LID) devices for urban region design could be important and effective ways to the flooding control and drainage service management of an urban stormwater drainage system (USDS). This paper investigates the optimal design and application of detention tank network and LID devices for achieving these multiple objectives in the USDS. The framework and method of LID-based multi-objective optimal design of detention tanks in USDS is first developed in this study, and a practical case in SA city of China is then taken for the application. The results of this study confirm the feasibility and validity of the proposed methodological framework for the LID-based multi-objective optimal design of detention tanks in the USDS. Specifically, both total investment costs and flooding risk have been greatly reduced by the optimal implementation of the detention tank and LID measures. Meanwhile, the results indicate that the LID devices may have global effect to the flooding control and the detention tanks can be locally efficient to reduce the flooding risk. Finally, the findings of this study are discussed in the paper for their practical implications to the practical design and management of USDS.     

Assessing the Impact of Urban Development and On-Site Stormwater Detention on Regional Hydrology Using Monte Carlo Simulated Rainfall

Water Resources Management - Urban development is a contributor to increased peak runoff and adverse hydrologic effects in regional catchments. On-Site Stormwater Detention (OSD) is a common way to...     

Multi-objective Optimal Design of Detention Tanks in the Urban Stormwater Drainage System: Uncertainty and Sensitivity Analysis

Design of detention tanks becomes important to the flooding control and drainage service management of an urban stormwater drainage system (USDS). While the hydrological and hydraulic models and methods have been widely developed in the literature for the optimal design and management of USDS, there is not yet a general methodological framework that is applicable for all practical systems. This is mainly because of various complexities in practical USDS, such as different design objectives (i.e., multi-objective design) and local design criteria and policies, as well as variety of inevitable uncertainties in the system. Previous work by the authors has focused on the first two aspects, in which a viable design framework has been developed and applied for multi-objective optimal design of detention tanks in the USDS under conditions of different local design criteria; and this paper deals with the third factor, aiming to explore and extend further the optimal design methodological framework to USDS with uncertainties. A real-life USDS in China is applied for this investigation. Uncertainty analysis is firstly conducted to characterize the importance of different uncertainty factors considered in the studied system. The uncertainty analysis result is thereafter incorporated into the previously developed multi-objective optimal design framework, in which the Monte-Carlo simulation method is adopted for the stochastic process investigation. The case application and analysis indicate different influences of uncertainty factors in the system to the multi-objective design results of detention tanks (total cost and flooding risk) in the studied USDS. The results and findings of this study are also discussed in the paper for their practical implications to the design and management of USDS.     

西北地区城镇发展与水资源研究

新中国成立以来,西北地区城市数量已由几个增加到60个,城镇人口也增加了十几倍,人口的城镇化水平达到32.6%,城市发展的总体质量也有了很大提高,但与东部地区相比,仍存在较大差距。一、现状与问题1.城市发展受制于生态环境西北地区深居内陆,干旱缺水,自然条件恶劣,生态环境脆弱,绝大部分地区是沙漠、戈壁和高原,适宜人类聚居的土地和绿洲很小,土地的人口承载力很低,城市发展的空间布局受到地形地貌和水资源条件的制约。黄河流域的城市主要沿黄河干流及其主要支流渭河分布,内陆河流域的城市主要分布在高山冰雪水源带下游。这种带状分布的水源…     

海河流域大中型水库雨洪资源利用潜力探讨

北方缺水地区,增加汛期雨洪资源利用率,已经成为洪水资源管理的重要课题。参考当前国内雨洪资源利用相关成果,结合水库特征参数（正常蓄水位、主汛期汛限水位、后汛期汛限水位、历史最高水位及其相应库容）及合理性假定,分析了海河流域大中型水库提高汛限水位增加雨洪资源利用的潜在能力。