西峰区雨水集蓄利用可行性研究     

郭龙  张新民  刘久如 《地下水》2015,(4)

雨水集蓄利用是缓解城市水资源压力的一条经济、快捷、有效的途径。通过对西峰区下垫面类型和降雨条件综合分析,在降水保证率为75%时,该区不透水集雨面可收集雨水量为2 964.96万m3,其中李岭村雨水可收集量为14.328万m3,对李岭村雨水可收集量进行经济效益分析可知,每年大约可为该村用水费用节约25万元,并结合西峰区自身特点,提出雨水综合利用的基本途径和措施,这对解决西峰区资源性缺水问题、减少洪涝灾害、改善生态环境、实现节水型社会的建设和水资源的可持续利用具有一定的指导意义。  相似文献   

三氯化铁絮凝小球藻的采收工艺     

高正  杨钰娟  薛春叶  刘巧巧  董京伟  钱平康  邓祥元 《广东海洋大学学报》2021,(2)

【目的】研究三氯化铁对小球藻絮凝采收效果的影响,并优化采收工艺条件。【方法】分析FeCl₃浓度、小球藻初始浓度和絮凝时间对小球藻采收效率影响,利用响应面法优化利用FeCl₃采收小球藻的工艺参数。【结果】单因素实验表明,FeCl₃质量浓度为0.6 g/L、小球藻初始质量浓度为0.42 g/L和絮凝时间为30 min时,小球藻的采收效率最高。响应面法分析表明,小球藻初始浓度对小球藻采收率有显著影响(P<0.05);影响采收效率的主次因素顺序为小球藻初始浓度>FeCl₃浓度>絮凝时间;FeCl₃浓度和小球藻初始浓度的交互作用对小球藻的采收效率有显著影响(P<0.05);FeCl₃浓度二次项对小球藻的采收效率有极显著影响(P<0.01)。【结论】利用FeCl₃采收小球藻的最佳工艺条件:小球藻初始质量浓度为0.55 g/L,FeCl₃质量浓度为0.6 g/L,絮凝时间为38 min,此时的采收效率为(98.6±1.9)%。  相似文献   

The role of human interventions in tree dynamics and environmental rehabilitation in the Sahel zone of Niger     

M. Larwanou  M. Saadou 《Journal of Arid Environments》2011,75(2):194-200

A study was conducted in 15 village territories of 3 regions in Niger. Among these sites, 4 were control and 11 had interventions comprising of farmer-managed tree natural regeneration (FMNR), water harvesting techniques (WHT) and windbreaks. The objective of the study was to determine the state of tree vegetation in terms of species diversity and harvestable volume and evaluate the environmental trend in the sites. An inventory of the vegetation was carried out during the rainy season using radial transects from the village centre, outwards, in addition to surveys with local communities.The results showed that tree diversity is enhanced in sites with interventions, and soil rehabilitation techniques and farmer-managed tree natural regeneration favor the rehabilitation and development of trees. The number of resprouts/seedlings varied with site, soil type and intervention. The number of harvestable trees depended on factors like caring, monitoring of cutting, types of intervention and ecological zone.Harvestable volume is a function of high regeneration rate, number of harvestable individual trees and site. Vegetation is improving in all the sites and local communities using tree products for their various needs. This study contributed to setting up a reference database for these sites.  相似文献   

Paired‐basin comparison of hydrologic response in harvested and undisturbed hardwood forests during snowmelt in central Ontario: II. Streamflow sources and groundwater residence times     

S. S. Monteith  J. M. Buttle  P. W. Hazlett  F. D. Beall  R. G. Semkin  D. S. Jeffries 《水文研究》2006,20(5):1117-1136

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The effect of truck traffic and road water content on sediment delivery from unpaved forest roads     

Gary J. Sheridan  Philip J. Noske  Robyn K. Whipp  Nimal Wijesinghe 《水文研究》2006,20(8):1683-1699

A study investigated the effect of truck‐traffic intensity and road water‐content on the quality of runoff water from unsealed forest roads. Three sections of a gravel‐surfaced forest road were instrumented and exposed to low and high levels of truck traffic during wet winter conditions and dry summer conditions between July 2001 and December 2002. Rainfall, runoff, road moisture, and traffic were measured continuously, and suspended and bedload sediments were integrated measurements over 2‐week site‐service intervals. The median suspended sediment concentration from the three road segments under low truck‐traffic conditions (less than nine return truck passes prior to a storm) was 269 mg l^?1, increasing 2·7‐fold to a median of 725 mg l^?1 under high truck‐traffic conditions (greater than or equal to nine return truck passes prior to a storm). These concentrations, and increases due to traffic, are substantially less than most previously reported values. When these data are expressed as modified universal soil loss equation (MUSLE) erodibility values K, accounting for differences in rainfall energy, site characteristics and runoff, high traffic resulted in a road surface that was four times more erodible than the same road under low traffic conditions. Using multiple regression, traffic explained 36% of the variation in MUSLE erodibility, whereas road water content was not significant in the model. There was little difference in the erodibility of the road when trafficked in low water‐content compared with high water‐content conditions (MUSLE K values of 0·0084 versus 0·0080 respectively). This study shows that, for a good quality well‐maintained gravel forest road, the level of truck traffic affects the sediment concentration of water discharging from the road, whereas the water content of the road at the time of that traffic does not (note that traffic is not allowed during runoff events in Victoria). These conclusions are conditional upon the road being adequately maintained so that trafficking does not compromise the lateral drainage of the road profile. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

Runoff and peak flow responses to timber harvest and forest age in southern Chile     

Andrs Iroum  Octavio Mayen  Anton Huber 《水文研究》2006,20(1):37-50

Runoff and peak flows in three experimental catchments with different forest conditions were analysed in a rainy temperate climate in southern Chile. The hydrological effects of clearcutting a Pinus radiata plantation covering 79·4% of the La Reina catchment were studied by analysing runoff and peak flows in the pre‐ and post‐harvesting periods. Mean annual runoff increased 110% after timber harvesting. Clearcutting generated a 32% mean increase in peak flows. Peak flow and runoff were examined in two adjacent catchments with different forest conditions. The older plantation in Los Ulmos 1 increasingly consumed more water than the younger plantation established at Los Ulmos 2, whereas differences in peak flows between these two catchments were not significant. Runoff and peak flows comparisons not only reflected changes in forest cover, but also the effect of rainfall characteristics during the study periods and the basins' morphologies. Comparisons between pre‐ and post‐harvesting peak discharges must be undertaken with caution, because a previous analysis at La Reina using a partial set of data overestimated changes in peak flows after timber harvesting. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

Paired‐basin comparison of hydrological response in harvested and undisturbed hardwood forests during snowmelt in central Ontario: I. Streamflow,groundwater and flowpath behaviour     

S. S. Monteith  J. M. Buttle  P. W. Hazlett  F. D. Beall  R. G. Semkin  D. S. Jeffries 《水文研究》2006,20(5):1095-1116

Impacts of forest harvesting on groundwater properties, water flowpaths and streamflow response were examined 4 years after the harvest using a paired‐basin approach during the 2001 snowmelt in a northern hardwood landscape in central Ontario. The ability of two metrics of basin topography (Beven and Kirkby's ln(a/tan β) topographic index (TI) and distance to stream channel) to explain intra‐basin variations in groundwater dynamics was also evaluated. Significant relationships between TI and depth to potentiometric surface for shallow groundwater emerged, although the occurrence of these relationships during the melt differed between harvested and control basins, possibly as a result of interbasin differences in upslope area contributing to piezometers used to monitor groundwater behaviour. Transmissivity feedback (rapid streamflow increases as the water table approaches the soil surface) governed streamflow generation in both basins, and the mean threshold depths at which rapid streamflow increases corresponded to small rises in water level were similar for harvested (0·41 ± 0·05 m) and forested (0·38 ± 0·04 m) basins. However, topographic properties provided inconsistent explanations of spatial variations in the relationship between streamflow and depth to water at a given piezometer for both basins. Streamflow from the harvested basin exceeded that from the forested basin during the 2001 melt, and hydrometric and geochemical tracer results indicated greater runoff from the harvested basin via surface and near‐surface pathways. These differences are not solely attributable to harvesting, since the difference in spring runoff from the harvested basin relative to the forested control was not consistently larger than under pre‐harvest conditions. Nevertheless, greater melt rates following harvesting appear to have increased the proportion of water delivery to the stream channel via surface and near‐surface pathways. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

Water conservation in the Arab region: a must for survival     

Gamal M. Abdo  Abdin M. A. Salih  Abdulmohsen Al-Sheikh 《寒旱区科学》2013,5(1):0157-0164

The Arab region covers an area over 13 million square kilometers in size, with almost 90% of its area classified as arid or extremely arid with very little precipitation, extremely high evaporation and almost no vegetation cover. The region is classified in many international reports as the poorest region in the world in the context of renewable water resources and critical water scarcity which hinders the socio-economic development of many countries in this region. The rapidly increasing population has reduced the per capita share of renewable water to less than the poverty line of 1,000 m 3 /(capita·a) and, in some Arab countries, to less than the extreme poverty line of 500 m 3 /(capita·a). This has led to over-exploitation of non-renewable groundwater and desalination of salty water in many countries with considerable costs and contamination of many renewable sources. Atmospheric processes responsible for aridity in the Arab region are projected to intensify due to climate change, resulting in an alarming decrease in precipitation and increase in evaporation rates. Many concerned entities in the region consider water security as a key element for food security and ultimately political stability. Hence, various efforts have been exerted to identify key problems and suggested solutions. The Arab Water Ministers Council of the Arab League, as well as Reports of the Arab Forum for the Environment and Development (AFED) and the recommendations of the 13th Regional Meeting of the Arab National Committees of the International Hydrological Programme of UNESCO (IHP), have all made similar recommendations on the need to address the issues of water scarcity in the Arab region which will be further discussed in this paper. However, none of these reports focused on "Water Conservation" as an equally important action for coping with water scarcity in the region. There are many definitions for "Water Conservation" in the scientific literature, including huge water savings from irrigation, industrial use, and domestic use as well as methods and approaches for augmenting water supply through non-conventional practices such as water harvesting and waste water reuse. In this paper, a review is provided for definitions, methods and impacts of water conservation and its role in alleviating water scarcity in the Arab region.  相似文献   

Low flow water chemistry in forested and pasture catchments,Mawheraiti River,Westland     

M. P. Mosley  L. K. Rowe 《新西兰海洋与淡水研究杂志》2013,47(3):307-320

Water samples taken at 19 locations in the Mawheraiti River catchment at weekly intervals during 1979–80 were analysed for sodium, magnesium, potassium, calcium, phosphate, nitrate, and ammonium ion concentrations and for electrical conductivity. Seasonal discharge effects were apparent, and lithology and land management practice also influenced solute concentrations. Solute concentrations were generally very low; nitrate and soluble phosphate were rarely greater than 0.05 mg.L^‐1 and ammonium was rarely greater than 0.01 mg.L^‐1. The 4 major cations (Na, Mg, K, and Ca) usually summed to less than 6 mg.L^‐1 much of which was supplied by precipitation. Forest management (clearfelling and slash‐burning) caused significant increases in solute concentrations, but concentrations declined rapidly during succeeding months and approached pretreatment levels after 2–3 years. The higher concentrations associated with forest management in small experimental catchments were rapidly diluted downstream; together with the low natural solute concentrations this suggests that harmful downstream effects of management practices are unlikely under low flow conditions.  相似文献   

Relationships of rainfall,river flow,and salinity to faecal coliform levels in a mussel fishery     

R. L. Brock  G. R. Galbraith  B. A. Benseman 《新西兰海洋与淡水研究杂志》2013,47(4):485-494

Faecal coliform levels were determined for sea water and shellfish flesh from farms of the green mussel, Perna canaliculus, in Pelorus Sound, Marlborough Sounds, New Zealand. Simple linear models were developed to relate logarithmically transformed data on the faecal coliform levels to measures of fresh water entering the mussel beds. These models support guidelines to restrict harvesting following periods of heavy rain in order to comply with shellfish sanitation standards. Alternative guidelines are suggested based on the volume of river water entering the sound or salinity.  相似文献