The renewable natural resources of many Asian countries have come under severe strain over the past two or three decades and most indicators point towards a continuation of this trend. The rate of degradation and depletion of these resources has been accelerated in proportion to the increasing population pressure. Deforestation, loss of biodiversity and a high rate of land use change have degraded the environment so that the food security and economic development of many countries are threatened. Unsuitable changes of land use have also contributed to natural disasters, such as soil erosion and salinization, floods and landslides.
Whilst a large amount of data related to land cover exists in Asia, most are not consistent over large geographic areas and therefore cannot be aggregated at regional and/or sub-regional scale. In some countries this situation is exacerbated by a severe shortage of country-wide reliable and up-to-date quantitative and qualitative information on land cover and current land use. In addition, the available land cover information has been acquired at different time periods, not allowing to produce consistent land cover maps and databases at regional level, sometimes not even at national level. As shown in figure 1, existing national land cover maps and data can be between one and ten years old or even older and follow different land cover classification systems and cartographic standards (scales, projections etc). These facts have proven to be the major limiting factors in proper planning, development and sustainable management of renewable natural resources in Asia.
The preparation of a regional land cover map and database and decision support systems for Asia, starting with a South East Asia component, has been discussed by the ESCAP Regional Working Group on Remote Sensing, GIS and Satellite-base Positioning, the Inter-agency Subcommittee on Space Applications for Sustainable Development in Asia and the Pacific and the Intergovernmental Consultative Committee on the Regional Space Applications Program for Sustainable Development, during meetings organized by ESCAP in Bangkok in June 1999. The meetings expressed strong interest in getting the project initiated in several countries in South-East Asia (in the first phase including the countries of Cambodia, China (Province of Yunnan), Lao People's Democratic Republic, Malaysia, Myanmar, Thailand and Viet Nam. The proposal was finally included in the Strategy and Action Plan on Space Technology Applications for Sustainable Development in Asia and the Pacific for the New Millennium of the Ministerial Conference on Space Applications for Sustainable Development in Asia and the Pacific in New Delhi, India, 15-20 November 1999.
Fig. 1: South East Asia - Land Cover / Land Use, available national maps and corresponding creation date
Resource managers require rapid and accurate methods for interpreting data for the development and management of the resources in Asia. Earth surface remote sensing including the mapping and analysis of the spatial distribution of land cover offers considerable advantages over alternative terrestrial methods of conducting such studies. Advantages include the potential for accelerated surveys; capability to achieve a synoptic view; availability of multi-spectral and multi-sensor data providing increased information; capability of repetitive coverage to depict seasonal and long-term changes; the relatively inexpensive cost of monitoring from space; the opportunity of integrating existing surveys into an monitoring system; the change detection capabilities (including back-look studies) needed by regulatory programs for updating information on vegetation/terrain conditions; availability of imagery with minimum distortion, thereby permitting direct measurement of important agro-physical parameters; and the fact that remotely sensed data provide a permanent record. In addition, standardized interpretation and classification methods can be applied over (sub)regions regardless of different land cover classifications applied in the individual countries, leading directly to regional land cover figures, from which national maps and statistics could be produced using GIS (Geographic Information System) technology.
Figure 2 explains the structure of the ASIACOVER Information System, highlighting the integration of such physical land cover data (standardized using the Land Cover Classification System (LCCS) developed in FAO) with social and economic data, such as agricultural production per sub-national unit, population density and dynamics, demand and supply patterns, infrastructure and others for comprehensive analysis. This GIS integrated information can be further processed using decision support systems for policy planning and environment management. The creation of a coherent regional database and the development of appropriate information management and decision support tools have become pre-requisites for sustainable agricultural development of countries in the region.
Hence, the aim of the ASIACOVER Project is to integrate this source of land cover data with socio-economic information to serve as a decision aid for environmental sound decision making.
Fig. 2: Structure of the ASIACOVER Information System
As a preparatory activity, development of a meta-database containing information on maps at various scales, land cover classifications systems, reports and statistics relevant for sustainable agricultural development has been initiated with support of the Czech government. This information and meta-data has been reviewed and integrated into an Access database. The database has 608 entries so far with basic information about country, subject, title and short description of the data, scale, creation date and last revision of the data. More detailed information about the single meta-data records is generally available.
Furthermore, a prototype of the information system (shown in figure 3) has been developed, which includes the following features:
Fig. 3: the ASIACOVER Information System Prototype
The ASIACOVER framework for action can be grouped into two major activities: the technical tasks and the institutional activities and co-operations. The technical tasks cover:
The institutional activities and co-operations include:
The preparation of a regional, standardized land cover map and database, and decision aid systems is a first step in the development of an integrated approach for environmental monitoring, food security, and sustainable development in South East Asia.
Future and follow-up activities will focus on the identification of areas and countries for which no recent and reliable land cover information exists and the definition of a strategy to fill these gaps in partnership with other interested organizations and institutions, such as UNEP, the Global Observation of Forest Cover and Land Cover Dynamics (GOFC/GOLD) initiative of GTOS (Global Terrestrial Observing System), the Land Cover Topic Center, the Joint Research Centre of the European Commission and potential donors. Focal point will be also to strengthen the capacities and the involvement of the participating countries for integrated use of information and decision support tools for improved analysis, planning and decision making for food security and sustainable agriculture and identification of needs to improve such capacities where required. Last but not least, the inclusion of other countries of the ESCAP (United Nations Economic and Social Commission for Asia and the Pacific) region in the land cover mapping process will be promoted and implemented.