P.P. Schot

Determinants of Land-Use Change Patterns in the Netherlands

Land-use-change patterns are the result of the complex interaction between the human and the physical environment. Case studies of the determinants of land-use change can help to analyse which theory is appropriate in a particular region and stimulate the development of new theoretic understandings. In this paper an empirical method is presented to analyse the pattern of land-use change that allows a wide range of factors, from different disciplines, to contribute to the explanation of land-use change. The method is applied to the Netherlands, based on an extensive database of land-use change and its potential determinants. Historic as well as recent land-use changes are studied. Historic land-use change is related mainly to the variation in the biophysical environment. Levels of explanation are low because of the inability to address the temporal variation in location factors. For the recent changes in land use high levels of explanation are obtained. The most important changes during this period are expansions of residential, industrial/commercial, and recreational areas. The location of these changes can be explained by a combination of accessibility measures, spatial policies, and neighbourhood interactions. On the basis of these results it is possible to define priority topics for in-depth analysis of land-use-change processes and suggest factors, relations, and processes that need to be included in dynamic land-use-change models that support land-use-planning policies.

Bottlenecks blocking widespread usage of planning support systems

Research on planning support systems (PSS) is characterized by a strong emphasis on the supply side, whereas little research has been undertaken on the successes and failures in the adoption of PSS within the planning community (demand side). What becomes clear from the existing research is that usage is not widespread. In this paper we aim to find the main bottlenecks blocking the widespread use of PSS in spatial planning. To achieve this, a global online survey was conducted in which almost 100 PSS experts participated and for which a theoretical framework from the field of business studies served as a basis. The results show that a multitude of factors cause the underutilization of PSS, their characteristics being human, organizational and institutional, as well as technical. In particular, the lack of awareness of and experience with PSS, alongside the relative lack of recognition of the value of PSS within the spatial planning community, tend to block widespread usage and adoption of PSS in planning practice. On this basis, we offer recommendations for the enhancement of PSS adoption, namely to disseminate more profoundly information and knowledge about the existence and benefits of PSS within the spatial planning community. Real-world example projects and in-depth research on potential benefits of PSS application in planning practice will be crucial in this.

Human impact on regional groundwater composition through intervention in natural flow patterns and changes in land use

Schot, P.P. and van der Wal, J., 1992. Human impact on regional groundwater composition through intervention in natural flow patterns and changes in land use. J. Hydrol., 134: 297-313. The relations between groundwater composition, land use, soil conditions and flow patterns on a regional scale are studied for the Gooi and Vechtstreek area in the Netherlands. This densely populated area consists of a glacier-created ridge with dry sand soils bordered by the Vecht and Eem River plains with wet peat and clay soils. R-mode factor analysis and Q-mode cluster analysis were applied to a set of 1349 groundwater analyses to determine the factors controlling groundwater composition and the main resulting water types. The results indicate that groundwater composition in the study area is affected on a regional scale by human activities through changes in land use and intervention in natural flow patterns. On the ridge, ground water is recharged by precipitation, which dissolves carbonates from the matrix of the sandy aquifer. Increased solute concentrations in shallow ground water, especially of nitrate, sulphate and potassium, indicate increased pollution resulting from urbanization and increasingly intensive agricultural activity over the past decades. in the Vecht River plain infiltration occurs as a result of drainage of polders and groundwater extraction on the ridge. Recharge occurs by precipitation and from polluted surface water to which ammonium, organic complexes and carbonic acid are added through decomposition of organic matter in the peat and clay soils. The carbonic acid results in enhanced dissolution of carbonates present in the soil and the underlying sandy aquifer. Oxygen depletion and subsequent low redox potentials result in denitrification, dissolution of manganese and iron oxides, and sulphate ro~duction. The flow of ground water from high-level to low-level polders causes displacement of a former stagnant brackish groundwater body under the Vecht River plain accompanied by increased mixing of fresh and brackish ground water.

A SWOT analysis of planning support systems

Insight into the strengths, weaknesses, opportunities, and threats (SWOT) of planning support systems (PSS) is fragmented between users and system developers. The lack of combined insights blocks development in the right direction and makes potential users hesitant to apply PSS in planning. This study presents SWOT of PSS from a combined user–developer perspective. We first express them in terms of combinations of planning task, PSS information function, and user, and subsequently use a literature survey, a series of interviews, and a web survey to gather views from developers, users, and PSS experts. The analysis shows that planners mainly use simple information storage and retrieval systems for exploration tasks, while the majority of PSS are technically much more advanced and aim to support complex tasks. The potential of these advanced PSS can only be realized if planners and system developers start to share knowledge and demands and identify opportunities in a cooperative PSS-development process. Without such a process, the advantages and opportunities of PSS will remain unexploited.

Groundwater chemistry and vegetation of gradients from rich fen to poor fen in the Naardermeer (the Netherlands)

In the eastern part of the Naardermeer peatlands (the Netherlands) a regional calcium-rich groundwater flow discharges (here often called the seepage area), whereas in the western part infiltration takes place. The ecological consequence of this hydrological pattern is reflected by the pattern in reedland communities. In the seepage area, which is characterized by Thelypteris-reedlands including many rare and endangered species (Caricion davallianae, Calthion palustris), there is a complex gradient of water types. The lime potential in the peat soil is clearly influenced by the hydrological gradient. In the ombrotrophic (poor fen) part of the gradient (containing species of Caricion curto-nigrae) the lime potentials are low and the groundwater contains low amounts of dissolved ions. The rare and endangered species (Caricion davallianae) are restricted to a small area with high lime potentials which is nourished by regional calcium-rich groundwater. High lime potentials were also measured in eutrophic reedlands influenced by brackish groundwater. Several species which generally occur in wet meadows even show a preference for this brackish environment. In a part of the seepage area succession from rich fen to poor fen and Alnus wood has taken place over a period of 40 years. This development has been caused by the diminishing amount of fresh seepage due to a lowering of the water levels in the surrounding area. The characteristics of poikilotrophic zones (contact zones between water flows) are discussed in relation to their significance for the preservation of endangered marsh species.

Hydrological systems beyond a nature reserve, the major problem in wetland conservation of Naardermeer (The Netherlands)

Abstract Ecological relations within a wetland depend on it is hydrology, but this is determined largely by what happens outside the wetland area. These statements are illustrated with respect to the Naardermeer nature reserve in the Netherlands. Succession and eutrophication have led to a reduction in the variety of vegetation types in the area. Eutrophication has been caused by a lowering of the water levels, deposition of guano in bird colonies, pollution of surface water and groundwater, and atmospheric deposition. The fact that most restoration activities have to be executed outside the wetland demonstrates that the management of the conservation of wetland ecosystems needs to operate on a regional scale. The conservation of a wetland depends on water levels. However, the qualitative aspects of hydrology are also important. Since landscape ecological relations with the surrounding area provide for transport of nutrients, a wetland is not isolated. Changes in hydrology have an impact on processes that affect the ecosystems in different ways. These relations are illustrated from a reserve in the centre of the Netherlands.

Dependency of local mesotrophic fens on a regional groundwater flow system in a poldered river plain in the Netherlands

The effect of regional, subregional and local groundwater flow systems on mesotrophic fen ecosystems was studied in the polders of the Vecht River plain that borders the Pleistocene ice-pushed moraine of Het Gooi. Variation in the vegetation and in the habitat factors (groundwater and peat soil) of fens depends whether or not the fens are connected to the outflow of the regional groundwater system.Changes in the regional groundwater flow system, caused by changes in the water management of the polders, are probably responsible for the deterioration of mesotrophic fens. Drastic measures will have to be taken to restore the hydrology on a regional scale if the mesotrophic fens are to be saved from extinction.Hydrological research that integrates the results of regional and local studies is essential if the ecology of fen ecosystems is to be understood.

Uncertainties in spatially aggregated predictions from a logistic regression model

This paper presents a method to assess the uncertainty of an ecological spatial prediction model which is based on logistic regression models, using data from the interpolation of explanatory predictor variables. The spatial predictions are presented as approximate 95% prediction intervals. The prediction model is based on logistic regression analysis of field data of a wetland area in the central parts of the Netherlands. The model predicts block average probability of occurrences of 78 wetland plant species for 500 m × 500 m blocks. The explanatory variables comprise groundwater chemistry, hydrological characteristics, and land use management. The uncertainty of the spatial model output is assumed to be a function of the uncertainty in the estimated regression coefficients and uncertainty in the interpolated values of explanatory variables. Monte Carlo analysis was used to assess the model output error due to uncertainty in both the regression coefficients and the explanatory variables. Correlation between errors in regression coefficients and spatial autocorrelation in explanatory variables are accounted for in the Monte Carlo analysis. Spatial patterns of the relative contribution of uncertainty of the regression coefficients to the total model uncertainty are presented. The patterns of the relative contributions of uncertainty to the total model uncertainty give information on the most effective way to reduce error, i.e. either by reducing uncertainty in the regression coefficients or in the interpolated input patterns. The spatial patterns and values of the 95% prediction intervals vary widely between species but are in general large and the relative contribution of the uncertainty of the regression coefficients is in general large (over 80%).

Applicability of Decision Support Systems for Integrated Coastal Zone Management

The use of Decision Support Systems (DSSs) in Integrated Coastal Zone Management (ICZM) has declined since the 1990s. In this article we investigate the opportunities for enhancing the applicability of ICZM-DSSs by considering the following research questions: (1) “What DSS functionalities are important for ICZM decision-making?” and (2) “which of these functionalities are part of present-day ICZM-DSS tools?” The first question has been answered by a literature survey. We identified knowledge- and process-related ICZM challenges and DSS functionalities that may help in meeting these challenges. For the second question, a selection of ICZM-DSS tools has been evaluated. The study shows none of the tools have all of the identified functionalities. The tools support either problem structuring/exploration or impact assessment while none of the tools manages to combine these functions. The implications for both DSS users (coastal managers) and DSS developers are discussed.

A GIS-based plant prediction model for wetland ecosystems

An existing non-spatial model for the prediction of response of wetland plant species on ecological factors has been transformed into a GIS-based prediction model which produces spatial output at the landscape scale. The input, spatial patterns of the ecological factors, were constructed with geostatistical spatial interpolation (kriging). With this GIS-based model the spatial patterns of presence and absence of 78 wetland plant species are predicted for an area with wetlands in the Netherlands of approximately 500 square kilometers. The GIS-based model has been validated, and the estimated uncertainty of the input has been propagated through the model. At the species level the output shows spatially coherent and non-random patterns. The validation is affected by the propagation of input errors through the model. The number of valid predictions declines approximately 10–20% when 95% confidence intervals are used in the validation. This study shows that it is feasible to use a geostatistical interpolation method to construct spatial patterns of ecological factors on a landscape scale and to use these patterns as input for a GIS-based prediction model. The added uncertainty on the input values however, affects the number of valid predictions of the model.