A philosophical case for process-based modelling of land use change

Quantifying and analyzing the impact assessment on land use change of urban growth using a timeline

Land use change occurs by altering natural landscape to manmade built environment. Rapid urban growth is the main factor for land use change at global level. Addis Ababa is one of the recent rapidly growing urban areas in Africa. Since 1983, the population has increased by nearly three times. However, the spatial expansion of the urban area has been much greater with urban sprawl, informal settlement, industry, condominium housing, and real estate development. The demand for urban land has been increasing at alarming rate both by city government, investors, and its residents. The city is primate and the population nine times the second largest city in the country. This study focused on quantifying and analyzing impact assessment of urban growth on land use change from 1986 to 2019. The study assessed the major change in extent and determinants of land use change through 33 years (1986-2019) and future growth scenario the next 30 years from 2019 to 2049. This study used Landsat image, base map of 1986, 1998, 2008, and 2019, to analyze built-up growth and land use change. Observation and interview have also taken to explore more on major urban growth and land use change driving factor from concerned bodies. The last, land use efficiency method was applied to measure land consumption rate and population growth rate. The result showed that in 1986, 1998, 2008, and 2019, built-up covered 21.83%, 42.31%, 59.42%, and 81.20% respectively. This shows that the agriculture and open space were rapidly changed to built-up by 32,486.67 hectares for housing, manufacturing, and infrastructure development. The result from concerned bodies has portrayed that the key determinants for urban land use change in the city were population growth at 4.2% per annum. Government led condominium housing, real estate development, and industrial development expansion including informal settlement has been rapidly reducing agriculture and open space through time. Therefore, unconventional planning approach could be exercised based on community interest for affordable high-rise building. Moreover, disseminate or decentralize industries beyond capital city in regional capital to reduce migration rate and rapid change of urban land use by creating employment opportunity and urban-urban linkage in the reginal capital rather than the capital city.

Improving the representation of adaptation in climate change impact models

Climate change adaptation is a complex human process, framed by uncertainties and constraints, which is difficult to capture in existing assessment models. Attempts to improve model representations are hampered by a shortage of systematic descriptions of adaptation processes and their relevance to models. This paper reviews the scientific literature to investigate conceptualisations and models of climate change adaptation, and the ways in which representation of adaptation in models can be improved. The review shows that real-world adaptive responses can be differentiated along a number of dimensions including intent or purpose, timescale, spatial scale, beneficiaries and providers, type of action, and sector. However, models of climate change consequences for land use and water management currently provide poor coverage of these dimensions, instead modelling adaptation in an artificial and subjective manner. While different modelling approaches do capture distinct aspects of the adaptive process, they have done so in relative isolation, without producing improved unified representations. Furthermore, adaptation is often assumed to be objective, effective and consistent through time, with only a minority of models taking account of the human decisions underpinning the choice of adaptation measures (14%), the triggers that motivate actions (38%) or the time-lags and constraints that may limit their uptake and effectiveness (14%). No models included adaptation to take advantage of beneficial opportunities of climate change. Based on these insights, transferable recommendations are made on directions for future model development that may enhance realism within models, while also advancing our understanding of the processes and effectiveness of adaptation to a changing climate.

The importance of socio-ecological system dynamics in understanding adaptation to global change in the forestry sector

Adaptation is necessary to cope with or take advantage of the effects of climate change on socio-ecological systems. This is especially important in the forestry sector, which is sensitive to the ecological and economic impacts of climate change, and where the adaptive decisions of owners play out over long periods of time. Relatively little is known about how successful these decisions are likely to be in meeting demands for ecosystem services in an uncertain future. We explore adaptation to global change in the forestry sector using CRAFTY-Sweden; an agent-based model that represents large-scale land-use dynamics, based on the demand and supply of ecosystem services. Future impacts and adaptation within the Swedish forestry sector were simulated for scenarios of socio-economic change (Shared Socio-economic Pathways) and climatic change (Representative Concentration Pathways, for three climate models), between 2010 and 2100. Substantial differences were found in the competitiveness and coping ability of land owners implementing different management strategies through time. Generally, multi-objective management was found to provide the best basis for adaptation. Across large regions, however, a combination of management strategies was better at meeting ecosystem service demands. Results also show that adaptive capacity evolves through time in response to external (global) drivers and interactions between individual actors. This suggests that process-based models are more appropriate for the study of autonomous adaptation and future adaptive and coping capacities than models based on indicators, discrete time snapshots or exogenous proxies. Nevertheless, a combination of planned and autonomous adaptation by institutions and forest owners is likely to be more successful than either group acting alone.

Can we be certain about future land use change in Europe? A multi-scenario, integrated-assessment analysis

The global land system is facing unprecedented pressures from growing human populations and climatic change. Understanding the effects these pressures may have is necessary to designing land management strategies that ensure food security, ecosystem service provision and successful climate mitigation and adaptation. However, the number of complex, interacting effects involved makes any complete understanding very difficult to achieve. Nevertheless, the recent development of integrated modelling frameworks allows for the exploration of the co-development of human and natural systems under scenarios of global change, potentially illuminating the main drivers and processes in future land system change. Here, we use one such integrated modelling framework (the CLIMSAVE Integrated Assessment Platform) to investigate the range of projected outcomes in the European land system across climatic and socio-economic scenarios for the 2050s. We find substantial consistency in locations and types of change even under the most divergent conditions, with results suggesting that climate change alone will lead to a contraction in the agricultural and forest area within Europe, particularly in southern Europe. This is partly offset by the introduction of socioeconomic changes that change both the demand for agricultural production, through changing food demand and net imports, and the efficiency of agricultural production. Simulated extensification and abandonment in the Mediterranean region is driven by future decreases in the relative profitability of the agricultural sector in southern Europe, owing to decreased productivity as a consequence of increased heat and drought stress and reduced irrigation water availability. The very low likelihood (< 33% probability) that current land use proportions in many parts of Europe will remain unchanged suggests that future policy should seek to promote and support the multifunctional role of agriculture and forests in different European regions, rather than focusing on increased productivity as a route to agricultural and forestry viability.