Land resources allocation: Global developments and future scenarios- a world-wide perspective
Winfried E.H. Blum
Professor emeritus of soil science at the University of Natural Resources and Life Sciences (BOKU)/Vienna/Austria since 2009.Former Member of the Executive Board of the International Council for Science (ICSU), Paris/France; Secretary-General of the International Union of Soil Sciences (IUSS) and Founding President of the European Confederation of Soil Science Societies (ECSSS).
Only 12 % of the global land and soil resources are suitable for food and fiber production. These resources and their sustainable use are threatened by 8 main global developments:
The increase of world population and its change in spatial distribution; the loss of fertile soils through sealing by urbanization, industrialization and further human impacts; changes in human life style with increasing demands for animal proteine and wasting of food, mainly in industrialized countries; increasing demands for bioenergy, especially biofuels ; changes in world economy, with increase of speculative performances in food production and marketing; climate change and its impact on food and fiber production; worldwide decrease in fresh water supply, and global spreading of alien and invasive plant and animal species, threatening local food and fiber production.
We will show the global distribution of land and soil resources and discuss future scenarios, based on visible trends in global developments threatening food security and the sustainable use of natural resources.
Keynote talk 2:
Causes of land degradation and its control in Serbia modeling, innovations, practice
Human activities in the hilly-mountainous region of Srebia in agriculture, forestry and nature in general, have caused disturbances in vegetative cover, stability and structure of the soil. Character and the intensity of erosion depend not only on natural, but also on social and economic factors. At present, it appears necessity to organize production on the principles of SLM. By this manner, soil as the most important natural resource could be preserved, and at the same time people would survive and remain in these regions. Paper takes into account modeling, innovations and practice in the case of Serbia.
Keynote talk 3:
Soil and water conservation based on appropriate land use planning for slope land
Kwong Fai Andrew Lo
A thorough land use planning in slope land watershed requires careful considerations on both its natural and social conditions. A modified “simple-accurate” method was used to estimate a land use potential value for each terrain unit. Soil loss estimate based on erosion modeling served as a guide for determining the most suitable land use type. The social feedback to the proposed land use planning was assessed through on-site interview with the land users. Results indicate large conflict and differences between land use planning based on natural condition evaluation and social needs. For sustainable soil and water resource use, land areas with moderate to high land use potential value can only be released for human activities, provided adequate soil and water conservation practices are being maintained. Land areas with less than moderate land use potential should be kept in their original natural stage. This recommendation should greatly improve the soil and water loss problems in the study area and ensure future sustainable development of soil and water resources in Taiwan.
Keynote talk 4:
Quantification of Gully Erosion Process on the Loess Plateau
Professor, Dean；Institute of Soil and Water Conservation, CAS & MWR;Institute of Soil and Water Conservation, Northwest A & F University
Gully erosion plays an important role in sediment yield and pollutant transportation within watershed. However, there is limited data available regarding description of gully erosion, which has restricted the development of process-based water erosion model at watershed scale. The objective of this study was to quantify gully erosion process (ephemeral gully and active-stage gully) on the Loess Plateau, based on integrated monitoring methods of filed observation, GPS (RTK), 3-D laser scanning technique and laboratory study. The results showed as follows:
1) Critical erosion models of ephemeral gully and gully were established according to GPS (RTK) measuring data.
2) Both of filed observation and laboratory study indicated that ephemeral gully erosion contributed above 50% to sediment yield at hillslope. Upslope runoff rate and slope gradient had great impacts on ephemeral gully development. Hillslope water erosion model covering ephemeral gully was developed.
3) Development process from rill to active-stage gully was simulated. The results showed that once gully occurred at hillslope, sediment yield increased 10 times, compared with sheet erosion. Gully erosion occupied above 80% of total hillslope erosion.
4) GPS (RTK) and 3-D laser scanning technique could be well used to monitor ephemeral gully and gully erosion process, measuring accuracy of GPS (RTK) and 3-D scanner were above 85% and 93%, respectively, which depended on gully development process and gully morphology.
5) Gully erosion development model was developed according to laboratory study data and its prediction accuracy was above 94%.
Keynote talk 5:
Challenges in current process-based soil erosion prediction models
Research Leader, USDA-ARS National Soil Erosion Research Lab, W. Lafayette, IN
Quantification of soil erosion has been traditionally considered as a surface hydrologic process with equations for soil detachment and sediment transport derived from the mechanics and hydraulics of the rainfall and surface flow. Under the current erosion modeling framework, the soil has a constant set of erodibility parameters, such as the USLE-K, interrill K (Ki), rill K (Kr) and critical shear stress (Tau-c), which quantify the resistance of the soil against the erosive power of the rain. Recent research findings show both soil erosion (or detachment) and sediment deposition vary significantly as the subsurface hydrologic condition is varied indicating a strong association between the surface and subsurface hydrology in controlling dominant erosion processes. These findings bring up challenges in the current process-based soil erosion model concept, such as the definition of erodibility parameters (Ki, Kr, and Tau-c), quantification of sediment transport capacity and sediment deposition. In this presentation, we will discuss research directions that will advance soil erosion science and new erosion model concepts.
Keynote talk 6:
Soil erosion and environmental protection:changing perspectives, challenges and opportunities
Des E. Walling
President International Commission on Continental Erosion, 1983-1991
President, International Association for Sediment Water Science, 1996-1999
President World Association for Sedimentation and Erosion Research (WASER) 2004-2010
Member Bureau International Association of Hydrological Sciences (IAHS) and Chairman, Board of Directors of IAHS Ltd., 1992- present
Member Steering Committee, UNESCO International Sediment Initiative 2002- present
Member Advisory Council International Centre for Research and Training in Erosion and Sedimentation, Beijing, People's Republic of China, 1984-92, 1997-2000, 2004-present