Trends in the Water Chemistry of High Altitude Lakes in Europe

Here we present the chemical trends of seven high altitude lakes, analysed within the AL:PE and MOLAR Projects of the EU (1999) and selected on the basis of the availability of complete and reliable data for the period 1984–1999. The lakes are representative of the Scandinavian Alps, the Cairngorm Mountains in Scotland, the Alps and the Pyrenees. Significant trends were identified for some indicators of acidification, for instance pH and alkalinity, but not all lakes reacted similarly to decreasing depositions of sulphate and base cations. Differences in lake response are discussed in relation to recent variations of atmospheric deposition chemistry and associated changes in climatic conditions. Beside individual variations of the studied lakes, depending, among other things, on altitude and morphology, catchment characteristics and climate trends play a major role for the reaction of high altitude lakes on changes in atmospheric depositions.     

SOIL SALINITY PREDICTION USING ARTIFICIAL NEURAL NETWORKS1

ABSTRACT: This study explores the applicability of Artificial Neural Networks (ANNs) for predicting salt build‐up in the crop root zone. ANN models were developed with salinity data from field lysimeters subirrigated with brackish water. Different ANN architectures were explored by varying the number of processing elements (PEs) (from 1 to 30) for replicate data from a 0.4 m water table, 0.8 m water table, and both 0.4 and 0.8 m water table lysimeters. Different ANN models were developed by using individual replicate treatment values as well as the mean value for each treatment. For replicate data, the models with twenty, seven, and six PEs were found to be the best for the water tables at 0.4 m, 0.8 m and both water tables combined, respectively. The correlation coefficients between observed salinity and ANN predicted salinity of the test data with these models were 0.89, 0.91, and 0.89, respectively. The performance of the ANNs developed using mean salinity values of the replicates was found to be similar to those with replicate data. Not only was there agreement between observed and ANN predicted salinity values, the results clearly indicated the potential use of ANN models for predicting salt build‐up in soil profile at a specific site.     

SUBWATERSHED SPATIAL ANALYSIS TOOL: DISCRETIZATION OF A DISTRIBUTED HYDROLOGIC MODEL BY STATISTICAL CRITERIA1

ABSTRACT: Complex hydrologic models, designed for simulating larger watersheds, require a huge amount of input data. Most of these models use spatially distributed data as inputs. Spatial data can be aggregated or disaggregated for use as input to a model, which can impact model outputs. Although, it is efficient to minimize data redundancy by aggregating the spatial data, upscaling reduces the detail/resolution of input information and increases model uncertainty. On the other hand, a large number of model inputs with high degrees of disaggregation take more computer time and space to process. Hence, a balance between striving for a maximum level of aggregation and a minimum level of information loss has to be achieved. This study presents a definition of an appropriate level of discretization, derived by establishing a relationship between a model's efficiency and the number of subwater‐sheds modeled. An entropy based statistical approach/tool called Subwatershed Spatial Analysis Tool (SUSAT) was developed to find an objective choice of an appropriate level of discretization. The new approach/tool was applied to three watersheds, each representing different hydrologic conditions, using a hydrologic model. Coefficients of efficiency and entropy estimated at different levels of discretization were used to validate the success of the new approach.     

Agricultural Land Use in an Environmentally Sensitive Area: An Assessment of an Agri-environmental Policy Measure

The agri-environmental measures included in European Union regulation 1257/99 encourage agricultural methods designed to protect the environment and maintain the countryside. The option of such environmentally favourable management of farming round a sensitive ecosystem including two lakes is examined. A multi-objective programming model is used to assess the cost of reducing the use of agrochemicals by changing the pattern of cropping alone. The solution shows that a substantial reduction in the use of agrochemicals can be achieved, if the support scheme provided for in this regulation can offset income loss due to reduced agrochemical use. The proposed aid results in a substantial reduction in the use of fungicides and insecticides, which are the most noxious agrochemicals.     

Enhancing biomass energy use in Kenya

This paper argues that in Kenya, environmental and economic factors will favour the continued use of biomass as a primary fuel for household and institutional cooking for the next decade or longer. The paper describes several successful projects which have improved the efficiency of urban charcoal use and of rural woodfuel use. The Kenya Ceramic Jiko, a more efficient version of the traditional charcoal stove, is a model programme sustained by free market competition, artisans participation, and widespread public acceptance. The Maendeleo stove is the best example of a successful rural woodstove project. The performance attributes of the stove, and its promotion through Kenya's largest women's organization, have resulted in the distribution of an estimated 26 000 Maendeleo stoves. Rural stove efficiency will become important as the cash-based economy expands in those areas. Agroforestry will also be critical to an enhanced use of biomass energy in Kenya. Experience to date shows that successful agroforestry programmes will have to be appropriate to local conditions and crops .     

Reducing life-cycle environmental impacts: An industry survey of emerging tools and programs

Corporate environmental practices have been evolving quite rapidly in recent years, as consumers express their preferences for environmentally friendly products and practices, as manufacturers look “upstream” and inquire into their suppliers' environmental practices due to liability and marketing concerns, and as company operating costs increase as a result of new environmental regulations. New corporate efforts are made to anticipate (rather than respond to) outside environmental pressures, to internalize costs, and to find strategic opportunities or competitive advantages based on company or product environmental performance. This article describes a survey and research project designed to explore one aspect of these evolving corporate practices—the use of analytical tools and associated programs, such as life-cycle assessment and design-for-environment—by companies to account for impacts throughout a product'S life-cycle.     

Water supply development and tariffs in Tanzania: From free water policy towards cost recovery

The article describes the historical development of water tariff policy in Tanzania from the colonial times to present. After gaining independence, the country introduced “free” water policy in its rural areas. Criticism against this policy was expressed already in the 1970s, but it was not until the late 1980s that change became unavoidable. All the while urban water tariffs continued to decline in real terms. In rural and periurban areas of Tanzania consumers often have to pay substantial amounts of money for water to resellers and vendors since the public utilities are unable to provide operative service. Besides, only a part of the water bills are actually collected. Now that the free water supply policy has been officially abandoned, the development of water tariffs and the institutions in general are a great challenge for the country.     

ECONOMIC EVALUATION OF AESTHETIC AMENITIES: A CASE STUDY OF RIVER VIEW1

ABSTRACT: Presence of a river in an urban setting may contribute positively to an aesthetically pleasing environment. Such aesthetic effects are not typically linked to specific economic activities and occur, for example, when residents are exposed to a river-view. Qualities enhancing the aesthetic value of the river include the presence of parks, trails, and vegetation along the riverbanks. The value of aesthetic amenities provided by the South Saskatchewan to the City of Saskatoon residents was estimated in this study using non-market methods. The implicit price of the river view was estimated using the Hedonic Price Model, whereas value through willingness to pay for property taxes or higher rents were also estimated using actual market data. The total annual value of the river to the City of Saskatoon through addition of aesthetic amenities was estimated at $1.2 million in 1989 dollars.