International Human Dimensions Programme on Global Environmental Change
چکیده
The study is devoted to the analyses of wooden residential estates typical areas of problem housing in the cities of former USSR in the city of Mogilev (Belarus). In spite of good housing conditions, this type of housing generally features ecologically/economically inefficient maintenance, and numerous negative environmental aspects such as extensive air and water pollution. Demolishing seems to be the best solution, however it is hardly possible because of financial incapacity of both municIndividual Urban Projects Land-Use/Land-Cover Change and Cities 13 IHDP Proceedings No. 6 ipal and central government, which cannot facilitate social housing programmes to provide all residents of wooden estates with new accommodation. We have analysed these problems in the framework of a system approach, examined the issues from the perspective of sustainability, and proposed economically affordable solutions. The main idea of Soviet city planning policy was to develop economically efficient cities. This meant developing compact settlements with clear functional zoning and good access to the industrial sector by public transportation. Yet numerous political, economic, and social problems prevented Soviet cities from implementing such sustainable ideas. Thus, acute housing problems led to hasty planning decisions, including those affecting the development and maintenance of the huge areas of wooden residential housing. However, after the World War Two, the development of these estates was considered an obvious solution to the housing shortage. As these areas sprawled out over the following two decades, they soon posed new urban planning problems, causing environmental, social, and economic instability. During 1970-80s in many of Soviet cities, big areas of wooden estates were replaced with multi-storied housing. Nevertheless, the wooden estates still occupy large areas in a number of cities. The main research question is: can a residential area be analysed as a dynamic autonomous system within the urban environment? The elements of system analysis, such as causal-loop diagrams (CLDs) (Cover, 1996), have been employed for the description of system interactions in the wooden residential areas. The temporal boundaries of the system are confined to the period since the sprawl of wooden residential estates in 1950-60s up to now. System interactions were analysed in descriptive CLDs; proposals for solutions to the problem are based on a predictive CLD. The study is based on field surveys, examining of unpublished databases of municipal agencies, analysis of literature, media, national and municipal executive legislation, archive documents, and data of expert polls and interviews. Wooden estates are very similar to the houses found in the Belarusian/Russian countryside. However, their planning structure is different from that common in villages. In Mogilev, wooden housing occupies approximately 60% of all residential areas. Usually wooden residential areas are deprived of municipal services such as central heating and proper sewage systems. Inhabitants of the wooden estates customary use wood/peat based stove heating, which resulted in additional air pollution and poses a radioactive threat (with no radiometric control of wood and peat). The unplanned sewage arrangements cause organic pollutants, pathogens and biogenic matter to leak into surface-waters and groundwater. The rural-style housing makes residents dependent on the outdoor environment: average temperature of January in Mogilev is -7,5°C, demanding a lot of fuel and making it difficult to use outdoor facilities (fetching water from communal outdoor water-pumps and boiling it up). Often the area also features such unfavourable microclimatic conditions as high humidity and high amplitude of mean daily temperatures, up to 12°C compared to the next areas (own data) that occur because of common valley allocation. Even though the indoor conditions are sufficient, these areas are deprived of basic services. They suffer from bad transport access, irregular and inefficient public transportation, sparse networks of vital social facilities, such as shops, polyclinics and schools, which may be situated 6-8 km away. All wooden estates are provided with electricity and telephone networks, and some enjoy access to pipes supplying natural gas. Nevertheless, there are too few telephones, which is particularly undesirable in view of the mostly aged population of the areas. Individual Urban Projects Land-Use/Land-Cover Change and Cities IHDP Proceedings No. 6 14 Unlike the majority of housing stock, wooden estates were privately owned even during the Soviet era. They have not passed into municipal ownership, so these areas are often neglected by the city council. This is immediately apparent when we look at road building and public transportation. Their most obvious benefit for newcomers to the city is low-rent accommodation. However, for many owners there is no profit to be made from offering apartments to rent, because few people are willing to live in the more remote areas, even for free. The subsidiary agriculture practised by the residents raises important public health issues. The domestically planted fruits and vegetables are important for the diet of local residents, who also sell them in the city's markets. However soils within the area are contaminated by oil products and heavy metals due to the high level of air pollution, so all the agricultural produce from the estate gardens are also polluted. The problem seems to centre on the irreconcilability of the rural style of life-system and the urban conditions. It has resulted in increased morbidity and a polluted natural environment, with negative consequences for public health. The problematic issues we have identified can be classified as follows (Table 1). As Table 1 shows, the unsustainable features outweigh the sustainable ones. We can therefore hypothesise that the system is characterised by ineffectiveness, which most likely results from weak municipal management. The wooden estates CLD in Fig. 1 is based on this assumption. It demonstrates that society/wooden estates inhabitants and municipal management do not have explicit feedbacks. Instead of political tools, we have administrative regulation, with decisions being taken without regard to stakeholder interests. This is preventing the formulation of sensible solutions that would be supported by all members of the community and would be feasible for the municipal budget. The latter is particularly important because tight budgets mean there is no money for large-scale renewal programmes. Table 1: The main issues for the system analysis of wooden residential areas Individual Urban Projects Land-Use/Land-Cover Change and Cities 15 IHDP Proceedings No. 6 Issues Negative Positive Urban planning Wooden estates are barriers to the city-planning actions; they are fire-unsafe; have ugly appearance; occupy large areas that demands extensive communication lines, pipe systems, and networks. The result is a huge additional loss of energy, water, construction materials, and fuel. An element of cityscape diversity Environmental The wooden estates are sources of water pollution; wood/peat-heated stoves cause air pollution through the emission of particles, which often contain Chernobyl radionuclides. Wooden residential areas put little pressure on the geological environment; they comprise a lot of green biomass. Public health External problems (the problems affecting wooden estate residents): exposure to polluted air, radionuclides, contaminated fruits and vegetables from estate kitchengardens; lack of municipal services; poor access to the area. Potentially wooden housing is more favourable for living in, than other types of housing available in the city. Internal problems of public health (those, which are originated from wooden areas and relevant to the public health of whole city), mostly resulting from stove-emitted particulate pollution and radioactive pollution, and by the consumption of contaminated produce from estate gardens, which can be bought in city markets. Social Areas are mostly inhabited by aged residents, who suffer from the lack of municipal amenities and have a particular need for social care and support but usually cannot afford to pay for the non-municipal services; a high risk of robbery due to relatively easy access to properties and an increased crime level in the areas. This type of housing is easily available to low-income population because of cheap rent. Cultural The low prestige of the areas shapes a common view among the rest of the city’s population of a ‘hostile environment’ within the areas of wooden estates. Wooden estates can be useful for the purposes of environmental education. Possible improvements to municipal policies are set at the optimised CLD (see Fig. 2). The administrative control by superiors is replaced by public opinion inputs as the basic driving force for municipal policies, i.e. the system receives feedback mechanisms. In this way the municipal authorities have more scope for agenda-setting and decision-making, which increases the chance of finding adequate solutions. We propose the following immediate actions to improve environmental and living conditions in the wooden estates, which would be affordable for the municipality: to connect to the central sewage system all of those estates located next to the trunk pipelines, to improve hygiene monitoring of aseptic tanks, to optimise street network and redesign public transportation routes, to improve heating in wooden housing, possibly replacing wooden/peat stoves either with natural gas-based or electric heating systems, to make stricter radiological inspections of wooden/peat fuel supply, to install system of ashes collection to prevent them from dispersing, to ban vegetables planting on estate gardens and marketing, to initiate a programme of the municipal support for housing in need of maintenance, to promote a project for the gradual provision of all municipal services. Fig. 1: Wooden residential estates CLD Fig. 2: Predictive CLD for wooden residential estates Acknowledgement The research forms part of a project funded by Swiss National Scientific Foundation. 3.1.4 Land use/cover change dynamics in Beijing under the open policy in China Chunyang He Peijun Shi This presentation introduces our study of the dynamics of land use/cover changes in Beijing. The work is divided into four parts: the background of urbanisation in China and Beijing under the open policy; our objectives for and ideas on land use/cover change dynamics in Beijing; our existing work in Beijing; and the work we expect to do in Beijing. Individual Urban Projects Land-Use/Land-Cover Change and Cities IHDP Proceedings No. 6 16 Background Beijing, the capital of China with a population of more than 13 million, is the political, cultural and international communication centre of China, and also has a history of more than 3000 years as a city and more than 800 years as one of the world's famous ancient capital cities. During the past two decades, driven by China's open policy, an extensive change in land use and land cover, mainly characterised by urbanisation, has taken place in Beijing as the population increased from 8.72 million in 1978 to 12.46 million in 1998 and the GDP rose from 10.84 billion RMB Yuan to 201.1 billion RMB Yuan (Zong 1998). Aspects of this change shows both particularity and universality. We look at the driving force, the change process, possible environmental impacts and so on, thus providing an effective case study area to understand the land use/cover change mechanisms under the open policy in China, especially the land use/cover change mechanisms in metropolitan areas (Zhang et.al., 2002). Objectives Supported by the modern techniques of RS, GIS and GPS, the land use/cover changes in Beijing are being systematically studied by analysing the Landsat TM/MSS data from 1975 to 1997. Our objective is to try to answer the following questions: How do the land use/cover changes in Beijing take place? What are the reasons for such tremendous changes? What are the impacts of such changes on the environment and the ecological systems in Beijing? Existing work Our work proceeds from the ideas of integration and system. At first, a conceptual model of land use/cover change dynamics was developed, which provides us with guidance and a flowchart for the whole project. Second, a new approach to detect changes, called improved change vector analysis, was developed to ensure the accuracy of the obtained land use/cover information in Beijing (He et.al, 2001). Third, we are analysing the landscape characteristics of Beijng with the support of GIS, giving special attention to the urbanisation process in Beijing and exploring the driving forces by integrating the statistical data, RS data and GIS ancillary data (He et. al, 2003). The fourth step is to develop a new City Expanding Model (CEM) based on the CA (Cellular Auto-mata) and Titenberg Model and to simulate urban development in Beijing from 1975 to 1997 by projecting urban growth patterns from 1997 to 2015 and considering various 'what-if' scenarios (Chen et.al., 2002). Expected work We hope the above-mentioned research will give us a better understanding of land use/cover changes in Beijing over the past two decades. We already know more about the characteristics and driving forces of the changes taking place. We are, for instance, trying to understand the impact of such changes on the urban heat island (UHI) in Beijing (Garratt et.al, 1993; Gillies et.al., 1995). A new research plan on the impact of land use/cover changes in Beijing on UHI will be part of our presentation. Our idea is that, with the various processes being influenced by different patterns, we can establish an optimal land use/cover pattern for eliminating the UHI if the mechanism between the land use/cover change and UHI is understood in simulation. Individual Urban Projects Land-Use/Land-Cover Change and Cities 17 IHDP Proceedings No. 6 3.1.5 Land-cover and land-use change in urban cities. A case in Cuitzeo's lake watershed Erna López Granados Topic Intensive use of natural resources calls for increasingly detailed inventories of its components and an investigation of the changes which took place in the past (Aaviksoo 1995). This is particularly important in areas undergoing fast, and usually unplanned, change, such as urban settlements in developing countries (Ramachandran 1992, Bocco and Sanchez 1995, Rodríguez 1995, Acosta 2002). Urban settlements in the developing countries are, at present, growing five times as fast as those in developed countries. Land-cover and land-use (LCLU) change analysis and prediction provides a tool to assess ecosystem change and its environmental implications (Lambin 1997). Despite its relevance, quantitative data describing where, when and how change occurs are incomplete or inexact (Turner et al. 1993). Thus, research on this subject is important in order to understand patterns of LCLU change in rural and urban areas as well as their social and environmental implications, with special emphasis on water consumption. In this research, the increase in urban settlements (US) was quantified for the last 25 years in the Cuitzeo's lake watershed, with special emphasis on Morelia, a fast-growing city in the watershed of Mexico. Cuitzeo lake is in a process of drying up; it was therefore considered important to understand the dynamics of the water change and the LCLU change over the few last years that might have contributed to this process. Objective We want to try to understand the relationship between water consumption, desiccation processes, and the growth of urban settlements over the last 25 years in the Cuitzeo's lake watershed. Methodology and data used In order to quantify the patterns of LCLU change, black and white panchromatic aerial photographs were interpreted. The approximate scales were 1:50,000 for 1975 (161 photographs) and 1:37,000 for 2000 (283 photographs). In addition, 1:50,000 basic and thematic cartography was used to describe relevant physical characteristics of the study area (INEGI 1975, 1996). In order to quantify LCLU change in Morelia City, land-cover patterns were interpreted from black and white panchromatic aerial photographs (1960, 1975 and 1990) corresponding to the city of Morelia and the surrounding urban fringe (nearly 200 km2). The approximate scales of aerial photography were 1:25,000 and 1:50,000 respectively. Final cartographic products were produced on the crudest scale. Landsat TM colour composite of 1997, with 30 m of spatial resolution, was used to compare results of prediction. GIS was used to generate and analyse the geographic data and its attributes. Land cover categories were forest, shrubland, grassland, rainfed agriculture, irrigated agriculture, forest plantations, aquatic vegetation, lakes, human settlements and eroded areas. Water consumption data for the different urban settlements and the rainfed agriculture, were obtained of the National Commission of water in Mexico. Expected results Rain-fed agriculture occupied the largest area in 1975, yet by 2000 the predominant category had become shrubland. Rain-fed agriculture diminished substantially in the Individual Urban Projects Land-Use/Land-Cover Change and Cities IHDP Proceedings No. 6 18 studied period. Shrubland and rain-fed agriculture are located mainly in hills with stony and shallow soils. The study area is characterised by the migration of the population to the capital of the state, the capital of the country and to the United States; thus abandoned rain-fed fields are increasing. These fields have undergone vegetal succession and are now covered by shrubland or forest. The tree plantations increased in the watershed as a result of government efforts to control eroding areas with varying degree of success. It was hypothesised that the desiccation of the lake was caused by an increase in the off-site effects of soil erosion (sedimentation) following the removal of natural vegetation. However, this investigation suggests that the desiccation process is more associated with the decrease in incoming water and the decrease in water quality rather than to sedimentation following erosion in the uplands. Human settlements (rural and urban) in the basin had increased significantly (284%). INEGI (population census of 1970) registered 385 localities (380,787 inhabitants). In 1995 (INEGI 1997) localities were 509 (837,775 inhabitants). The increase in water consumption for agriculture and urban use is the major cause of desiccation. The population has increased in 220% between 1970 and 2000; this growth induced an increase in water consumption and an increase in urban sewage that flows untreated into the lake. Acosta et al. (2001) analysed the increase in urban settlements (US) in the watershed. INEGI (1997) defined US as those larger than 2,500 inhabitants (there are 25 such settlements in the watershed). In 1975 the surface occupied by US was 3,141 ha; in 2000 it increased to 10,939 ha. By contrast, population density diminished in all the US. There are two cities whose population have diminished due to emigration processes; however, these cities are still growing in surface area. People working outside the country send money to their families in the region to build houses that they plan to occupy later on returning to Mexico. The main urban area of Morelia underwent the greatest growth (from 709 ha in 1960 to 3,368 in 1990), and fragmentation (López 2001). One of the major reasons for this expansion was the migration from rural areas in Michoacán, following a slump in the prices of agricultural products. A second reason was the migration from other urban areas, such as Mexico City and other cities in central Mexico (López 2001). Other urban settlements were incorporated by Morelia, a very common process in fast growing urban settlements that lack adequate planning. Most of the urban area (46%) is now located on the alluvial plain, occupying former agricultural land of prime quality. On the basis of the existing descriptions, we can evaluate the relationship between the urban and agricultural water consumption and the Cuitzeo ́s Lake desiccation process. 3.1.6 Measuring Urban Sprawl by using Remote Sensing and GIS Techniques Madhavi Latha Karumudi Objectives Studying the urban sprawl patterns of Hyderabad, India, by using the Entropy Approach over different time scales. Quantifying urban sprawl trends using GIS at various land use sites viz., commercial, industrial, residential, sensitive and mixed zones. Individual Urban Projects Land-Use/Land-Cover Change and Cities 19 IHDP Proceedings No. 6 Methodology Shannon's entropy (Hn) is used to measure the degree of spatial concentration or dispersion of geophysical variable (Xi) among n zones It is calculated by Hn=Sni Pi log (i/Pi) where Pi is the probability or proportion of a phenomenon (variable) occurring in the ith zone (Pi=xi/Sni xi), and xi is the observed value of phenomenon in the ith zone, and n is the total number of zones. Conversely, an evenly dispersed distribution among the zones will give a maximum value of log (n). Hn = Sni Pi log(1/Pi/log(n)) The buffer function of a GIS can be used to define buffers of zone from city/town centres of roads and thus the density of land development in each of these buffer zones can be used to calculate the entropy. Further, measurement of difference in entropy between time t and t+1 can be used to indicate the magnitude of change of urban sprawl, i.e.