Geography and GIS Support Understanding of Relationships Between Society and Environment

The environment of the Earth has many close connections and relationships with human activity.It is also now more widely recognized that a profound transformation of the Earth's environment is taking place and that many of these changes are the result of human action. Intensification and diversification of resource use, globalization, growth in population, as well as patterns of population distribution and migration, and changing flows of information, products and technology, have produced changes in landscapes and ecosystems of the Earth's surface.They also raise questions about the capacity of environmental systems to sustain change and support life.Land use and land cover changes have most recently been recognized as both centrally important causes and consequences of environmental change, and to have influence at geographic scales ranging from the local to global and time scales from short to long.

Over the last decade an international research program, the Land Use and Land Cover Change Program (LUCC), and related series of local, regional and national programs and projects have examined the patterns and processes of land use and land cover change. Some patterns of change are well known as global phenomena, for example desertification and tropical deforestation.Other changes are more local, but nonetheless familiar and with important consequences and impacts, for example residential development and urban sprawl.A wide variety of processes that produce these changes have also been documented.These represent a mix of environmental, social, economic, political, institutional and technological forces.Underlying forces include climate factors, national policies, for example on trade, and population growth.More immediate causes include human activities at local scales, including cropland expansion, development of transportation networks, changes in markets, resettlement and wood extraction for fuel.

Many studies of land use and land cover change have used the data management and analytical power of GIS, frequently combined with the data collection capacity of remote sensing instruments and GPS.GIS and remotely sensed imagery have been used to map the extent of change at local, regional, national and global scales.GIS has also helped to gain insights into the current and recent condition of land use and land cover in the landscapes, environments, communities and places where changes have occurred.For example, GIS offers the capability of coupling a time series of data developed from remotely-sensed images that document change in land cover, with maps of transportation networks, markets and population distribution that describe how people use the landscape and land resources.This description of the coupled human and environmental system for a specific place can in turn be linked with surveys and other spatially detailed inventories of human preferences, decisions and actions to make models of change.Models describe environmental processes and human decision-making, and, when linked to GIS, help with analysis and development of understanding of the behavior of land use as a reflection of coupled natural and human systems.

In many ways, therefore, GIS is the central technology in the science of land use and in study of society's interactions with environment. Alongside GIS, geography offers a unifying suite of intellectual tools that encourage the interdisciplinary thinking that underpins evaluation of coupled social and natural systems.Spatial thinking is at the core of understanding change over time and variability across space, and of relating social systems to environmental systems.Although social and environmental science each provide general principles that guide our understanding of social and natural systems separately, the use of geographic location as a referencing system and a geographical understanding of place provide a framework that allows them to be related.

Studies of the geography of land use and land cover changes are thus made possible by the power of geographic location in GIS which can relate descriptions of very different aspects of the socio-economic and environmental landscape.Used appropriately, GIS also supports place-based explanation of the modification of landscapes by human action.The product is a better understanding of the mutual interaction between human activity and change in environmental systems.This is important not only for understanding the patterns of land use and land cover produced over recent and longer-term history, but also for identifying trajectories of change in response to the processes that produced change, and for predicting what might happen in the future.

A new international program representing an important extension and refocusing of the last decade's work on land use and land cover change has recently started.The Global Land Project is a core program of the International Geosphere-Biosphere Program and International Human Dimensions of Global Environmental Change Program.The Global Land Project will combine study of the dynamics of land systems and an understanding of the consequences of land system change with efforts directed at increasing our knowledge of sustainability of land systems, and their vulnerability and resilience in response to hazards and disturbance.

The Global Land Project builds on the LUCC program by integrating the interdisciplinary science of land use and land cover change with ecosystem science that focuses on the description, maintenance, and enhancement of ecosystem services.The objectives of Global Land Project include identifying the nature of change in coupled natural and human land systems, assessing how ecosystem services are affected by changes, and to identify the character of vulnerability and sustainability in land systems.Ecosystem services describe the benefits obtained from regulation of ecological processes manifest in climate and weather regulation, disease control and flood control. Taken together, study of land use change and ecosystems services provide an opportunity to gauge the sustainability of coupled human and environmental systems at a range of geographic scales and over a variety of time periods.

GIS and other geographic technologies will be central to both the science and success of the Global Land Project.Ecological change has a strong geographic component and is influenced by the spatial configuration and geographic context of ecological processes operating at a range of scales.GIS provides the opportunity to link description of ecological systems and models of ecological processes, with descriptions of land systems and the social and environmental processes that influence their development and trajectories of change in space and time.The measurement of ecosystem services to identify biological, social economic and other values presents an opportunity for imaginative thinking that combines the intellectual contents of ecology, geography and a variety of other disciplines, but the technical expertise, analytical skills, and the capacity for synthesis of GIS specialists.

Extending this integration of intellectual and technical expertise to focus on sustainability, resilience and vulnerability provides a fresh challenge.However, it is a challenge that gives geography, and geographical technologies, a strong practical relevance as economic development, population growth and land use changes continue, in the face of continued environmental changes and hazards.