Harvesting of rainwater and brooklets water to increase mountain agricultural productivity: A case study from a dry valley of southwestern China

In semi-arid valleys of southwestern China, seasonal shortage of water is the major contributing factor to low and unstable crop yield. Harvesting of both rainwater and brooklets water in the semi-arid valleys of Ningnan county of Sichuan Province has brought about considerable economic and environmental change. Brooklet water is collected throughout the year but mainly during the rainy season in a series of ponds while rainwater is harvested in underground tanks constructed on road side or land boundaries with only a small opening above ground to save limited cropland. Increased water availability has promoted cultivation of sugarcane, tobacco, and mulberry, and increased per unit area yield of food crops. Sericulture, sugarcane and tobacco have become three important sources of farmers' income. The water harvesting has contributed considerably to increased rural income, poverty reduction, reduced soil erosion and improvement in overall environment. Government has played a key role in planning and implementation of water harvesting programmes. Financial support of government and clear ownership of water harvesting facilities are critical for the success of the programme. Application of similar water harvesting techniques in other areas with similar biophysical conditions would contribute to enhancing the rural economy and alleviating poverty.     

Assessment of heavy metal pollution in wetland soils from the young and old reclaimed regions in the Pearl River Estuary, South China

Soils were sampled in three types of wetlands from the young (A) and old (B) reclaimed regions of the Pearl River Estuary. They were analyzed for total concentrations of heavy metals to investigate their distributions and pollution levels in both regions. Results showed that most heavy metals in ditch and riparian wetlands did not significantly differ from those in reclaimed wetlands in A region, while significantly lower for Cd, Cu, Pb, and Zn in reclaimed wetlands in B region, suggesting higher effects of long-term reclamation. Iron, Cr and Cu were identified as metal pollutants of primary concern and had higher contributions to the total toxic units compared to other metals. Almost all metals exceeded their lowest effect levels and Fe and Cr even exceeded the severe effect levels. Multivariate analysis shows that Fe and Mn are controlled by parent rocks and other metals mainly originate from anthropogenic source.     

生态公益林价值核算研究

论文采用成本法、意愿调查法、森林环境效果评价法及木材需求曲线修正法等方法对井冈山林区生态公益林价值进行核算,并对其结果进行分析。经计算,成本法(社会贴现率以10%计算)、意愿调查法、森林环境效果评价法及木材需求曲线修正法的计算结果比例为0.4592∶0.2185∶1.7106∶1。分析认为,以木材需求曲线修正法得出的每年森林资源价值平均为1302元hm²较为合理可作为区域内生态公益林的补偿值成本法计算的年成本值597.9元hm²可作为生态公益林补偿的最低限值意愿调查法计算的每年支付意愿值284.5元hm²可作为当地受益群众对生态公益林的补偿费用。     

典型电器工业区河涌沉积物中多环芳烃的分布、来源和潜在生态风险

为综合评估电器加工制造业对纳污水体多环芳烃（PAHs）的污染影响,对广东典型电器工业区佛山市顺德区容桂街道河涌沉积物的PAHs含量进行了空间和垂直分布、来源以及生态风险评估研究.结果表明,16种优先控制PAHs中有12种检出率达100%,其余4种具有不同的检出率.ΣPAHs含量范围为343.5～2 099μg.kg-1,均值为1 215.9μg.kg-1.PAHs组成特点为2～3环〉4环〉5～6环.在0～40 cm垂直尺度内,4个分层层面的ΣPAHs含量和种类均无显著变化.同分异构体比率分析显示,空间尺度上PAHs主要污染源来自石油、生物质以及木柴燃烧等活动.垂直尺度上燃烧类型反映了从生物质向石油燃烧为主的转变.河涌沉积物总量污染指标和污染因子指标显示了相同的重度污染特征,各监测断面污染程度由高到低为：S7〉S2〉S4〉S3〉S6〉S1〉S5.沉积物质量基准法（SQGs）评价显示S7、S2、S3等位点具有潜在的生态风险.包含居民区和制造业集中区的各监测点ΣPAHs含量分布显示,该地区PAHs污染和电器制造业存在没有直接相关性.     

再生水河道菹草管控的生态响应研究

在北京地区典型再生水补水型河道开展试验,通过在菹草(Potamogeton crispus)生长期对其进行基于生物量控制条件下的不同收割强度处理,研究光照强度等环境影响因子、菹草生长特征、浮游动物及底栖动物分布的响应机制,以期为北京再生水补水型河道提供生态修复技术支撑与沉水植物管控方案.结果表明:①菹草收割强度对水体浊...     

光驱动水凝胶用于非常规水源处理的研究进展

近年来淡水资源短缺问题日趋严重,使用非常规水源作为淡水资源的补充受到了广泛关注.海水和大气水是非常规水源中很重要的组成部分,最近十年水凝胶逐渐被应用到处理这些水源的技术之中,如光热蒸馏、正渗透、水富集.由于水凝胶与水分之间独特的相互作用,使得水凝胶与之前所研究的水处理材料相比在吸水性能和脱水性能方面都具有极大的优势.此外,其在自然光照条件下就可以实现水处理工艺的运行,从而使得水处理过程更加低碳环保.本文首先介绍了海水淡化和大气集水方法的发展历程,之后分别介绍了水凝胶应用于海水淡化和大气集水方面近几年来的研究进展,从评价指标、处理原理、影响因素、净化能力等方面对各种处理工艺进行总结,最后提出了光驱动水凝胶用于非常规水源处理方法的研究前景.     

Nontarget-plant risk assessment for pesticide registration

The approach developed by Environment Canada to assess risk to aquatic and terrestrial plants in nontarget habitats potentially exposed to pesticides evaluated for registration is described. An anonymous sample of pesticide submissions is used to illustrate the approach and to examine its merits and limitations in relation to test species, response variability, testing protocols, ecological relevance, and comparability with other regulatory agencies. Future directions are identified, particularly in relation to impending nontarget-plant testing guidelines for pesticide registration in Canada. This approach incorporates some of the latest research and developments in the field of risk assessment for plants. The novelty of this approach also lies in the use of the plant screening data routinely generated by chemical pesticide companies, which is intended to provide a maximum amount of information to evaluators at minimal increment cost to registrants. The proposed approach can serve as a basis for guideline development and modernization for other jurisdictions.     

REVISITING STATE WATER RIGHTS LAW1

ABSTRACT: Water resources professionals should be engaged actively in revisiting state water rights law. During the past four years, sponsored by the American Society of Civil Engineers with cooperation of other water resources organizations, over a hundred engineers, hydrologists, geographers, lawyers, administrators, educators, water users, and other persons interested in water law have been preparing a Model State Water Rights Code. Preliminary drafts of the Model Code have been considered in four states, and its provisions will be disseminated nationally to state legislators and other policy makers upon formal publication in September 1994. The Model Code gathers the best provisions from state water laws into comprehensive regulated riparian and prior appropriation provisions, includes commentaries explaining how its textual sections address water resources planning and management issues, and references similar language in current state water statutes. The goal of the Code Project is to provide materials which will assist legislators so they can enact effective, efficient, and equitable water laws. In the future, the Code drafting group will expand its efforts to develop legal guidelines for allocating shared transboundary water resources, water quality law, federal water statutes, and other water resources legal issues.     

ASSESSMENT OF STORMWATER RUNOFF FOR RECYCLE IN COOLING TOWERS AT KSC,FLORIDA1

ABSTRACT: In addition to measuring the quantity of stormwater runoff generated during ten rainfall events from the Vehicle Assembly Building (VAB) area of Kennedy Space Center (KSC), historical rainfall records were also used for determining the feasibility of implementing a program of stormwater recycling to air conditioning cooling towers. It was projected that 0.182 million gallons per day (MGD) of runoff would be generated from the VAR area during a year of average rainfall (48 inches); only 0.117 MGD is required for coolant makeup water in the VAR area. Due to the seasonal variations in rainfall, stormwater recycling may not always meet all the cooling water demands.