Modelling the impact of stormwater source control infiltration techniques on catchment baseflow

Stormwater management increasingly recognises the need to emulate, to the maximum extent possible, the flow regime of receiving waters in their pre‐development state. Hydrological models play a central role in assessing the catchment‐scale impacts of alternative stormwater management strategies. However, because of the complexity of physical processes involved in urban hydrology, particularly subsurface flows, the predictive performance of such models is often low. We investigated how the structure of hydrological models influenced the prediction of urbanisation and stormwater management impacts on baseflow. We calibrated three conceptual models of the same reference catchment and compared the modelled flow regime from different stormwater management scenarios, using each of the three model structures. Scenarios were assessed using six metrics, characterising the whole streamflow regime and in particular baseflow. Although the three models of the reference catchment represented the observed hydrograph well, the most complex structure developed using a thorough diagnostic of the catchment behaviour better captured the change in hydrological regime during dry years. Predictions of baseflow changes due to urbanisation varied significantly according to the model structure. Similarly, the models showed distinct responses to the stormwater management scenarios applied, especially for scenarios involving infiltration of stormwater at source. Our results confirm the importance of predicting the consequences of land use changes with conceptual models that are consistent with the hydrological behaviour of the study catchment. Future work should help to quantify the uncertainties due to model structure and thus provide practical guidance to the use of catchment models for assessing stormwater management strategies. Copyright © 2013 John Wiley & Sons, Ltd.     

现代水文水资源学科体系及研究前沿和热点问题

在对国内外水问题进行科学识别的基础上,分析了水循环的"自然-人工"二元演变模式,明晰了水循环及伴生水化学、水生态和水沙过程的相互关系,初步阐述了现代水文水资源学科体系的构成。在对国际水文水资源研究发展趋势及热点和前沿问题进行阐释的基础上,结合中国水文水资源研究现状及水问题解决的实践需求,论述了中国水文水资源研究的学科体系的构成,并分析其重大研究方向。在变化环境和高强度人类活动影响下,水循环在驱动力、结构及参数等方面已呈现出显著"自然-人工"二元特征。现代水文水资源研究正由传统"还原细化"研究向综合交叉方向发展,并由传统基于单个水文环节的研究过渡到基于二元水循环过程的研究上来,原型观测与数学模拟的结合已成为其关键研究手段。中国水文水资源研究需要进一步强化水循环及伴生过程演变机理识别与定量模拟方面的基础研究,完善水资源评价、配置、调度、水权分配、水价定价理论和技术等方面的应用基础研究,服务于节水型社会建设、水环境保护与水生态修复、水资源综合管理、防灾减灾与应急管理、民生水利及现代水利建设与管理等实践需求。     

贵州省安顺市耕地表层土壤养分元素分布特征

本文依据安顺市表层土壤样品地球化学调查数据,从有机质、碱解氮、速效磷及速效钾四个方面分析,表明安顺市近90%以上的耕地表层土壤有机质、碱解氮及速效钾含量均处于中等以上水平,速效磷的含量有90%以上的耕地处在中等以下水平。依据本次的研究结果,可以为安顺市农业科学施肥提供更好的指导,以便通过人为的手段来调节土壤养分含量,为农作物提供更好的生长环境,从而达到增产、增质、增效的目的,更好的服务于农村、农业、农民。     

Testing of the SIBERIA landscape evolution model using the Tin Camp Creek,Northern Territory,Australia, field catchment

The SIBERIA landscape evolution model was used to simulate the geomorphic development of the Tin Camp Creek natural catchment over geological time. Measured hydrology, erosion and geomorphic data were used to calibrate the SIBERIA model, which was then used to make independent predictions of the landform geomorphology of the study site. The catchment, located in the Northern Territory, Australia is relatively untouched by Europeans so the hydrological and erosion processes that shaped the area can be assumed to be the same today as they have been in the past, subject to the caveats regarding long‐term climate fluctuation. A qualitative, or visual comparison between the natural and simulated catchments indicates that SIBERIA can match hillslope length and hillslope profile of the natural catchments. A comparison of geomorphic and hydrological statistics such as the hypsometric curve, width function, cumulative area distribution and area–slope relationship indicates that SIBERIA can model the geomorphology of the selected Tin Camp Creek catchments. Copyright 2002 © Environmental Research Institute of the Supervising Scientist, Commonwealth of Australia.     

Changes in the thermal and hydraulic regime within the active layer in the Qinghai-Tibet Plateau

The change trends of air temperature,precipitation and evaporation from 1999 to 2008 shows that the climate in the Qinghai-Tibet Plateau permafrost region had become warmer.The analysis of the systematic active-layer data monitoring network along the Qinghai-Tibet Highway indicated that the active-layer thickness had been increasing and the soil temperature was rising.The soil temperature was rising in winter but not at the end of spring or during the entire summer.With thickening and warming of the active layer,the liquid water content of the active layer had an obvious downward migration and liquid water content in the top horizons decreased,but in the deeper horizons it increased.     

盘锦湿地芦苇群落土壤碱解氮及溶解性有机碳季节动态

基于2005年4～10月盘锦湿地芦苇群落土壤不同土层土壤碱解氮及溶解性有机碳的观测资料,分析了盘锦湿地芦苇群落土壤碱解氮与溶解性有机碳(DOC)的季节动态。结果表明:不同土层碱解氮、溶解性有机碳的季节动态并不相同。0～10 cm土层碱解氮与DOC季节动态相似,6月土壤碱解氮与DOC含量均最高,分别为244.86 mg/kg和13.16 mg/L。8月碱解氮含量最低,为139.18 mg/kg;9月DOC含量最低。10～20 cm土层DOC的季节性动态变化与表土具有相似性,峰值均出现在6月,谷值出现在9月;10～20 cm土层碱解氮最低值出现在6月,与0～10 cm土层不同。20～30 cm土层内,4～7月DOC几乎无变化,8月DOC含量最低,9月增加;4～5月碱解氮波动较大,5月降到102 mg/kg,6月增加到151 mg/kg。研究表明,盘锦湿地芦苇群落土壤微生物活性与凋落物分解对DOC及碱解氮的季节动态有很大的影响,同时温度、降水量及冻融也影响着DOC及碱解氮的季节动态。     

岩溶生态系统中的土壤

在偏碱富钙的岩溶生态系统中,其土壤具以下特征：①形成速率十分缓慢,形成1 m厚的土层需要250～7 880 ka,因而对岩溶区土壤侵蚀的评价应有新的认识;②高含量的钙离子使土壤腐殖质中胡敏酸的含量比例较高,且稳定性好,不易分解的腐殖质使石灰土供应营养元素具缓效性;③微量营养元素含量及有效态具有不平衡性,且随钙镁含量的降低,其有效率显著提高;④粘粒含量高,当有机质含量高时,具有良好的团粒结构,有较好的供水、供肥能力,反之其团粒结构就失去稳定性,使土壤有效水含量、抵御水土流失的能力降低;⑤岩溶地貌制约石灰土的类型及分布,并延缓其向地带性土壤演化。因此石灰土资源的有效利用应从岩溶学、土壤学与植物学相互协调的角度进行生态经济规划。     

城市设计暴雨频率曲线线型的研究

城市排水规划需有一定设计标准的暴雨值,这类设计暴雨的特点是历时短、设计标准不高和统计分布呈反S形。提出了用两端有限对数正态分布和广义指数分布作为频率曲线线型进行计算,可避免用Γ分布适线欠佳的缺点。通过实例,发现采用这两类分布,计算简便,能获得适线较好的结果。     

Interpretation of groundwater level monitoring results in karst aquifers: examples from the Dinaric karst

The paper presents an attempt to determine the characteristics of karst aquifers using information on groundwater level (GWL) in natural holes and boreholes with different data quantity and time resolution of GWL measurements. In this paper the particulars of karst aquifers were analysed for four examples from the Dinaric karst. In all four study areas, aquifers are formed in bare, deep and well‐developed Dinaric karst consisting of Cretaceous limestones. The first example represents a wide area of Imotsko polje in the karst. The aquifer was analysed on the basis of infrequent water level monitoring in natural karst water features (jamas, lakes, wells) and discharges of springs and rivers. The karst aquifer in this example is complex, non‐homogenous and variable in space and time, which is frequent in the Dinaric karst. Regardless of the aforementioned it was possible to determine its elementary characteristics. The second example represents 10 wells used for the water supply for the city of Pula. The GWL and salinity were measured once a week in the period between 1981 and 1996. Even though these measurements were relatively infrequent in space and time, they served as bases for assessment of average and maximum aquifer conditions as well as boundaries of saltwater intrusion. In the third example only a portion of aquifer of the karst spring Blaz, which is in the contact with the Adriatic Seas, has been analyzed. It is a spring with an intrusion of salt water. For purposes of study of saltwater intrusion, 26 piezometers were drilled in its vicinity in which GWL, salinity and temperature were measured once a day during 168 days, a period comprising one complete cycle of seawater intrusion and retreat. These measurements proved the existence of dispersed discharge from the aquifer into the sea and its non‐homogeneity in space. In the fourth example GWL was measured continuously in 10 deep (up to 300 m) piezometers in the hinterland of the Ombla Spring catchment. The measurement period lasted 2 years (January 1988 to December 1989). The analyses are made with hourly data. The results made it possible to determine numerous characteristics of the karst aquifer and a significant non‐homogeneity of groundwater distribution in karst aquifers, depending more on the underground karst phenomena than the surface karst forms. Copyright © 2000 John Wiley & Sons, Ltd.     

A model of the redistribution of disaggregated soil particles by rainsplash

A model of the dispersion of splash droplets from a single raindrop impact on a sloping soil surface is combined with a theory of the entrainment of mineral particles from a disaggregated mixture in splash droplets to obtain a model of the dispersion of such particles by a raindrop impact. Stochastic modelling techniques extend this further to a model of the spatial redistribution of soil on a plot after a period of rainfall. Since the model is probabilistic and physically based it enables the incorporation of further advances in the understanding of splash erosion at all stages and can simulate the effect of the stochastic nature of rainfall and soil properties on the process. Several different situations are simulated. These include the movement of marked soil particles from point sources and the spatial patterns of erosion on a sloping plot. The model can also simulate the differential erosion of different soil particle size fractions.