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891.
This study presents the modelling approach and impact assessment of different strategies for managing wetland water resources and groundwater dynamics of landscapes which are characterised by the hydrological interactions of floodplains and the adjacent lowlands. The assessment of such impacts is based on the analysis of simulation results of complex scenarios of land-use changes and changes of the density of the drainage-network. The method has been applied to the 198 km2 Lower Havel River catchment as a typical example of a lowland–floodplain landscape. The model used consists of a coupled soil water and groundwater model, where the latter one is additionally coupled to the surface channel network. Thus, the hydrological processes of the variable saturated soil zone as well as lateral groundwater flow and the interactions between surface water and groundwater are simulated in an integrated manner. The model was validated for several years of significantly different meteorological conditions. The comparison of lateral and vertical water balance components showed the dominance of lateral flow processes and the importance of the interactions between surface water and groundwater for the overall water balance and the hydrological state of that type of landscape.The simulation of land-use change scenarios showed only minor effects of land-use change on the water balance and groundwater recharge. Changes of groundwater recharge were particularly small within the wetland areas being part of the floodplain where interactions between surface water and groundwater are most pronounced. Alterations in vertical groundwater recharge were counter-balanced by the lateral interaction between groundwater and surface water. More significant deviations in groundwater recharge and storage were observed in the more peripheral areas towards the catchment boundaries which are characterised by greater groundwater distance from the surface and less intense of ground water–surface water interactions.However, the simulation results assuming a coarsening of the drainage network density showed the importance of drainage structure and geometry for the water balance: The removal of the artificial draining ditches in the floodplain would result in significant alterations of total groundwater recharge, i.e., less recharge from winter to early summer and an increase of groundwater recharge during summer and autumn. Furthermore the different effects of groundwater recharge alterations on the dynamics of groundwater stages within the wetland areas close to the floodplains compared to the more peripheral areas could be quantified. Finally, it will be discussed that a well-adjusted co-ordination of different management measures is required to reach a sustainable water resources management of such lowland–floodplain landscapes. 相似文献
892.
M. Brigante M. DellaGreca L. Previtera M. Rubino F. Temussi 《Environmental Chemistry Letters》2005,2(4):195-198
The photolytic decomposition of hydrochlorothiazide in water was investigated. Irradiation of the drug was performed in pure water and sewage treatment plant water with a solar simulator and by direct sunlight. Here we show that three photoproducts were obtained. Two of them were formed in yields much higher than 10%. An environmental risk assessment of hydrochlorothiazide should take into account also these photoproducts in a complete analytical and ecotoxicological evaluation. 相似文献
893.
Diego Andrés Lugo 《Journal of Land Use Science》2020,15(2-3):343-367
ABSTRACT This article, through the use of political ecology perspectives on coercive conservation, aims to explain how in two separate Colombian Natural Parks and buffer zones, environmental policies designed to (re)take control of the frontier, have produced a similar territorial differentiation in the contention of illicit activities. Los Farallones in the Colombian Pacific and La Macarena/Puerto Rico in the Ariari region have experienced different stages of the armed conflict and are at the center of this analysis. I argue that in the contexts of both conflict escalation (1998–2007) and conflict de-escalation (2008–2016), the State in its attempt to control the frontier has not only had military intervention in areas of conservation but has also reinforced environmental programs that attack illegal mining and coca, producing both a territorially differentiated containment of illicit activities and an uneven progression of the illicit frontier. 相似文献
894.
Ojeda J. Sanchez E. Fernandez-Palacios A. Moreira J. M. 《Journal of Coastal Conservation》1995,1(1):109-118
This paper deals with the application of satellite images to characterize some aspects of the circulation dynamics of the
Tinto-Odiel estuary using turbidity patterns as ‘natural tracers’. 15 images (Landsat TM and Spot HRV) were processed to provide
synoptic, instantaneous views of the circulation patterns under different environmental conditions. In addition, a comparison
was made between results of oceanographic field work, using biplanes and fluorescent tracers, and satellite image turbidity
patterns used as ‘ground truth’ data for specific hydroclimatic situations. This approach allowed (1) the identification and
mapping of dynamic processes of interest during a theoretical tidal cycle, (2) the elaboration of additional information on
the ‘flow schemes’ at the mouth of the estuary with improved spatial and temporal resolution, and (3) the supply of basic
data to improve the knowledge of exchange processes between estuarine and coastal waters. The results of this study are considered
to be useful for the management of the estuarine system. 相似文献
895.
本文概述土地退化的原因和状况。通过对广东山区土壤和东江流域低产耕地的大批土壤剖面分析数据的统计和推算,结果表明,广东的林地退化面积约占全省陆地面积的35%;旱地土地退化面积占全省旱地总面积的95%;水田土地退化面积约占全省水田总面积的25%。根据广东的省情,提出土地退化治理的对策:提高认识,增加投入,组织力量,开展调查摸底;制订整体治理规划,分步实施;明确治理的中心任务,推进面上治理利用,加强研究工作。 相似文献
896.
Non-compliance and the quota price in an ITQ fishery 总被引:4,自引:0,他引:4
This paper examines the effects of non-compliance on quota demands and the equilibrium quota price in an ITQ fishery. I show that whereas lower quota prices are implied unambiguously by expected penalties which are a function of the absolute violation size, the expectation of penalties based upon relative violations of quota demands can, under certain conditions, produce higher quota prices than in a compliant quota market. If there are both compliant and non-compliant firms in the fishery, the result would then be a shift in quota demand from compliant to non-compliant firms, rather than the reverse. The findings are generally applicable to quota markets in other industries, including pollution permit markets. 相似文献
897.
Xyleborini are a species-rich tribe of ambrosia beetles, which are haplodiploid and typically mate among siblings within their
natal brood chamber. Several characteristics of this tribe would predict the evolution of higher levels of sociality: high
genetic relatedness within galleries due to inbreeding, high costs of dispersal and the potential benefit of cooperation in
brood care within the natal gallery (e.g. by fungus gardening, gallery extension, offspring feeding and cleaning). However,
information on the social system of these beetles is very limited. We examined the potential for cooperative breeding in Xyleborinus saxeseni by monitoring dispersal in relation to brood size and composition. Results show that adult female offspring delay dispersal
despite dispersal opportunities, and apparently some females never disperse. The females’ decision to stay seems to depend
on the presence of eggs and dependent siblings. We found no indication that female offspring reproduce in their natal gallery,
as colonies with many mature daughters do not contain more eggs than those with few or no daughters. There is a significant
positive relationship between the number of females present and the number of dependent siblings (but not eggs), which suggests
that cooperative brood care of female offspring raises colony productivity by improving survival rates of immatures. Our results
suggest that cooperative breeding is likely to occur in X. saxeseni and possibly other xyleborine species. We argue that a closer look at sociality within this tribe may yield important information
on the factors determining the evolution of cooperative breeding and advanced social organization. 相似文献
898.
An important topic in the registration of pesticides and the interpretation of monitoring data is the estimation of the consequences of a certain concentration of a pesticide for the ecology of aquatic ecosystems. Solving these problems requires predictions of the expected response of the ecosystem to chemical stress. Up until now, a dominant approach to come up with such a prediction is the use of simulation models or safety factors. The disadvantage of the use of safety factors is a crude method that does not provide any insight into the concentration–response relationships at the ecosystem level. On the other hand, simulation models also have serious drawbacks like that they are often very complex, lack transparency, their implementation is expensive and there may be a compilation of errors, due to uncertainties in parameters and processes. In this paper, we present the expert model prediction of the ecological risks of pesticides (PERPEST) that overcomes these problems. It predicts the effects of a given concentration of a pesticide based on the outcome of already performed experiments using experimental ecosystems. This has the great advantage that the outcome is more realistic. The paper especially discusses how this model can be used to translate measured and predicted concentrations of pesticides into ecological risks, by taking data on measured and predicted concentrations of atrazine as an example. It is argued that this model can be of great use to evaluate the outcome of chemical monitoring programmes (e.g. performed in the light of the Water Framework Directive) and can even be used to evaluate the effects of mixtures. 相似文献
899.
In 1994, the sinking of the ‘Apollo Sea’ off the West coast of South Africa led to the deposition of ca. 2 500 tons of heavy
fuel oil over 150 km of coastline. The impact of the spill on rocky shore invertebrates, rock-pool fish fauna and rock lobsters
was assessed by conducting surveys shortly after the spill, and again two months later. Where possible, results of these surveys
were compared with existing data from before the sinking of the Apollo Sea. Among the fish fauna of rock-pools, changes in
total density of fishes were largely due to changes in the abundance ofClinus superciliosus and were within the range of natural variation for the species and the community as a whole. Community structure of the rock-pool
fish fauna also remained unaffected.
At three of four impacted rocky shore sites no changes could be detected in overall benthic community structure, although
the winkleNodilittorina africana was affected. At the fourth site, a boulder beach, statistical analysis showed distinct differences in community structure
between heavily and lightly contaminated areas, as well as between all areas compared with previously existing data. There
were also significant changes in the lightly oiled areas between the first and second surveys after the spill.
Oil-fouled lobster were found at one of three sites investigated. Ca. 7 % of the seabed in this particular area was polluted.
Antennae and forelegs of almost all lobsters in the vicinity of the oil were fouled. Examination of the gut-contents confirmed
that oil inhibits the ability of lobster to feed. Although there was no evidence that mortalities of lobster were caused by
the spill, growth rates may be reduced by the decreased feeding rate. Overall, the impact of the spill was strikingly less
than might have been predicted from the effects of other oil spills.
Nomenclature: Names of fish species follow Smith & Heemstra (1986). 相似文献
900.
C. Soulsby D. Hannah R. Malcolm J. K. Maizels R. Gard 《Journal of Coastal Conservation》1997,3(2):143-154
This paper reports the results of 12 years of hydrological monitoring at the St. Fergus dune system in northeastern Scotland.
The site is adjacent to the UK’s largest gas terminal and the dunes are crossed in five places by North Sea gas pipelines
which were constructed between 1976 and 1990. These are buried beneath the dune system which was restored after pipeline installation.
The dunes include a substantial freshwater wetland which is seasonally flooded and provides an important habitat for waterfowl.
The hydrogeology of the site is characterized and the hydrogeological processes that sustain this wetland feature are considered
including recent climatic fluctuations.
Nomenclature: Names of vascular plants follow Clapham et al. (1962). 相似文献