地下水资源可更新性的环境同位素研究

论述了环境同位素在研究地下水可更新性中的应用现状,分析研究区氢氧稳定同位素、氚和14C放射性同位素、CFCS的分布特征及其指示意义,对比人类开采前后地下水的同位素特征.结果表明:盆地地下水的可更新性随不同深度、地域、含水层的不同而各异,人类活动加强了浅层与深层地下水之间的水力联系.     

Sand and gravel mining: effects on ground water resources in Hancock county,Maine, USA

Based on this preliminary study, existing sand and gravel mining regulations (in Maine, USA) can be inferred to provide some protection to water resources. Sand and gravel deposits are important natural resources that have dual uses: mining for construction material and pumping for drinking water. How the mining of sand and gravel affects aquifers and change aquifer vulnerability to contamination is not well documented. Mining regulations vary greatly by state and local jurisdiction. This study test metrics to measure the effectiveness of mining regulations. The sand and gravel aquifer system studied is covered with former and active gravel pits to nearly 25% of its areal extent. Data from homeowner interviews and field measurements found scant evidence of changes in water quantity. Water quality analyses collected from springs, streams, ponds and wells indicate that the aquifer was vulnerable to contamination by chloride and nitrate. However, water quality changes can not be related directly to mining activities.     

Objectives,ownership and engagement in Lao PDR’s REDD+ policy landscape

Reducing Emissions from Deforestation and forest Degradation (REDD+) is envisioned as a performance-based incentive to influence forest use behavior and governance towards the preservation and management of forests. In relatively forest-rich Lao PDR, the policy space that REDD+ planners are attempting to navigate is populated by enduring political and economic interests that affect the country’s forest estate. A further layer to the problem of REDD+ planning is the tension between often expert-driven, externally proposed solutions; national ownership over interventions; and the extent of political will to take action to reform currently unsustainable patterns of forest and forest land exploitation. This paper draws from a series of semi-structured interviews conducted in 2013–2014, to develop a political and institutional analysis of the limitations to the effectiveness of REDD+ in steering towards a lower forest-derived emissions trajectory in Lao PDR. While internationally-driven projects follow long-standing national objectives to varying degrees, it remains unclear how REDD+ can target main drivers of deforestation in the absence of a more politically engaged and nationally-owned planning process, that also challenges the prevailing logic of avoiding these drivers. Despite the importance of improving domestic ownership over REDD+, this would arguably be of limited impact unless oriented towards transformational change that would seek to overcome political and economic barriers to avoided deforestation. Stronger ownership could be developed via more mutually driven REDD+ planning, while tackling main drivers of deforestation necessitates as a starting point the engagement of powerful actors that have so far been absent from REDD+ debate.     

Anthropogenic impact on sediment composition and geochemistry in vertical overbank profiles of river alluvium from Belgium and Luxembourg

The geochemical study of alluvial sediments allows to reconstruct pollution through time. Geochemical and sedimentological variations recorded in 40 vertical overbank sediment profiles from Belgium and Luxembourg can be classified in three dominant pattern types:• type 1 profiles with dominantly non-anthropogenically influenced geochemical distribution patterns. These profiles are devoid of anthropogenic particles such as charcoal, plastic, brick and slag fragments, with the exception, in some cases, of their uppermost parts. Background concentrations thus are displayed throughout the profile (subtype 1A). However, in this group, profiles displaying anomalous values caused by the presence of heavy minerals (subtype 1B) or by base metal mineralisations in the catchment (subtype 1C) also occur;• type 2 profiles displaying clear evidence of anthropogenic influences. Most of these profiles display a gradual increase in heavy metal content in their upper part, with values doubling or tripling (subtype 2A). However, other profiles display a dramatic increase in pollution-related elements caused by past or present-day heavy industrial activities in the catchment (subtype 2B). Here also the sedimentological patterns reflect the influence of the industrial activities;• type 3 profiles contain features related to pedogenetic translocations of mobile elements. Apart from classical pedogenetic features such as illuviation/eluviation, the mobility of As and Cd is of particular importance. From a sedimentological point of view, these profiles do not necessarily differ from type 1 or 2 profiles.It should be noted that in some profiles, pattern types can be superimposed. Type 2B profiles are of particular environmental concern, because the potential release of heavy metals may have consequences for agricultural activities or groundwater contamination in the catchment. Furthermore, reworking of polluted sediments temporarily stored in the alluvial plain can also have negative effects on the ecosystem.     

河源市中心城区土壤环境地球化学特征研究

对广东省河源市中心城区的表层土壤进行了取样调查工作,测定了金属元素的含量,并对其污染状况进行评价,数据表明:城区表层土壤存在多种重金属元素异常,其中Pb和As表现出富集特征,来源指向汽车尾气及其它工业活动的排放。重金属含量要明显低于其它大城市,该市环境风险指数(IER)为0.43,属于2级指数范畴,总体评价为低环境风险,但作为一个主要以轻工业、农业和旅游业为主的城市,也存在进一步恶化的趋势。     

Groundwater recharge estimation using chloride,stable isotopes and tritium profiles in the sands of northwestern Senegal

A study of environmental chloride, deuterium, oxygen-18, and tritium in deep sand profiles (35 m) has been carried out in order to estimate their relative value for measuring average groundwater recharge. The investigation was located at a 0.1-km² site in Quaternary sands near the northwestern coast of Senegal in a zone of rainfed agriculture. By using a steady-state model for duplicate unsaturated zone chloride profiles, the long-term average recharge at the site was estimated to be 30 mm yr^–1 or around 10% of the average precipitation (290 mm). The chloride concentration of adjacent shallow groundwater was relatively uniform and comparable to the unsaturated zone average, while the spatial variability in the depth distribution of Cl^– in the unsaturated zone was considerable. Stable isotope (deuterium and oxygen-18) data show that there is some isotopic enrichment due to direct evaporation through the soil surface. The degree of heavy isotope enrichment is proportional to the extent of evaporative loss and there is good correspondance with the chloride enrichment. Nevertheless, stable isotopes cannot be used quantitatively to estimate the recharge. The excellent preservation of the peak in thermonuclear tritium in precipitation in the unsaturated zone at depths between 12 and 20 m enables an estimated annual recharge of 24 mm yr^–1 in this area to be calculated, using the piston flow model. Agreement therefore between Cl and³H as tools for recharge measurement is reasonable over the site.     

Environmental change in Jiaozhou Bay recorded by nutrient components in sediments

Inorganic or bulk organic chemical indicators, including organic carbon (OC), total nitrogen, organic nitrogen (ON), fixed ammonium (N_fix), exchangeable ammonium, exchangeable nitrate, organic phosphorus (OP), inorganic phosphorus (IP), and biogenic silica (BSi), were examined in a 3-m core collected in Jiaozhou Bay (JZB) to decipher how the environment has changed during the preceding two centuries of increasing anthropogenic influence in this region. Concentrations of BSi, OC, and OP reveal overall increases to ca.30 cm (∼1984), then decreased toward the surface, probably reflecting a decrease in the productivity of overlying waters since 1984. Aquaculture might play an important role in the decrease of nutrient elements in the upper layers recorded in sediments. The decreased molar BSi/OC ratios upcore may be due to a change in dominance from large- to small-sized diatoms, as shown in other research. However, the shift may also be related to changes from heavily-silicified to lightly-silicified diatoms or to non-siliceous forms such as dinoflagellates. ON concentrations increased towards the surface sediment, which is most likely consistent with the increase in fertilizer application and wastewater discharge. Concentrations of IP, total P, and N_fix all decreased conspicuously upcore at 41 cm depth (∼1977), and were largely consistent with the decrease in rainfall and freshwater discharge to JZB. Our data suggest that the environment has significantly changed since the1980s. Anthropogenic activities in the watersheds may exert a substantial influence on carbon cycling processes in estuaries and potentially the coastal ocean.     

Anthropogenic pressures on productive soils in Corlu and Cerkezkoy

Unplanned land use is mainly arising from previous regional (local) planning policies based on economic growth, which resulted in the misuse of the land. The fertile lands are converted to industrial/urban areas along with forest areas converted to agricultural zones which directly affect the flora and fauna in a negative way. This study aims to identify the land use transformations by using Remote Sensing and GIS due to prior socio-economic return focused politics resulting in environmental degradations. Additionally, this paper presents an analysis of the transformation of fertile lands into industrial/urban zones with respect to Land Capability Classes. The study area is one of the most urbanized and industrialized zones in Turkey. The reason behind this transformation lies solely in the fact that the aforementioned area is quite appealing to industrialization due to its easy access to infrastructure and its compliance with the spatial requirements. Up until now the development plans of the region have been prepared with a socioeconomic agenda promoting the economic growth while disregarding the ecological and environmental balance, which unfortunately boosted the large-scale degradation of the environment. Although the focus area is within a zone suitable for industrialization, this region also takes place within a wide river basin (Ergene River Basin) making it an ideal location for highly productive crop cultivation (LUC Classes 1 to 4), which is a rare commodity in long term.     

An empirical analysis of IOPCF oil spill cost data

This paper reports on recent analysis of oil spill cost data assembled by the International Oil Pollution Compensation Fund (IOPCF). Regression analyses of clean-up costs and total costs have been carried out, after taking care to convert to current prices and remove outliers. In the first place, the results of this analysis have been useful in the context of the ongoing discussion within the International Maritime Organization (IMO) on environmental risk evaluation criteria. Furthermore, these results can be useful in estimating the benefit of regulations that deal with the protection of marine environment and oil pollution prevention.     

Newly discovered reefs in the southern Abrolhos Bank,Brazil: Anthropogenic impacts and urgent conservation needs

The Abrolhos Bank is an area of high ecological, socio-economic importance and harbour the richest and most-extensive coral reefs in the South Atlantic. Here we report the discovery of shallow (12–25 m depth) reef complex with ten large biogenic structures, intermediate between the typical mushroom-shaped pinnacles of the northern Abrolhos Bank (17°–18° S) and the small patch reefs found on the central/southern coast of the Espírito Santo State (19°–20° S). The newly discovered reefs harbour a relatively rich and abundant reef community, with 73 fish and 14 benthic cnidarian species, including endangered and commercially important ones. We discuss on urgent needs of properly mapping and understanding the ecological functioning of this reef system. Information provided here is a baseline for future impact evaluations, particularly considering the recent worst environmental disaster of Brazil from a dam collapse in Doce river that affected the region.