AGRICULTURE - Remote Sensing for Crop Assessment


In a global context crop assessment has two rather contrasting but equally important roles. On the one hand, the identification of drought and the potential shortages likely to occur in developing countries as a result are central to government and international response programmes and relief efforts; on the other hand burgeoning subsidies in industrial agriculture have necessitated the development of sophisticated techniques to maximise the effectiveness of these subsidies in controlling production. A third, related component of crop assessment has recently begun to emerge in the form of individual crop forecasting, for example for sugar beet and potato, allowing a complex market for such crops to develop.

While it is farmers that strive for profitable, efficient and sustainable production from renewable resources (crops in particular but also livestock, timber and forage), it is increasingly the decision makers and planners who have to address and respond to issues of over- and/or under-production, imports, exports and quotas, conservation and protection, food security, subsidy allocation and administration. Explicit within this mandate is federal production levels, in particular crop assessment including areas under production, yields, predictions/forecasts, changing land use and land ownership, changing management and technical inputs, farming systems and actual crops planted and harvested.

When adequate information on these component parts of the agricultural system are available or can be collected, political and economic concerns can be addressed through improved management programmes to ensure both the sustainable utilisation of the available resources for food and of appropriate high level decisions regarding food movements, pricing and imports/exports. The premier way of acquiring this data in a cost-effective and synoptic way is through the use of rigorous remote sensing methodologies.

The use of remote sensing for data gathering, allied to the introduction of Geographic Information Systems (GIS) as a powerful tool to process that data in conjunction with information collected using traditional field techniques helps overcome traditional data volume constraints. Remotely sensed data permits the preparation of base, terrain evaluation, land use classification and land degradation maps. Agriculture and associated vegetative phenomena are dynamic; a correct appraisal of conditions at any time is essential for forecasting trends and patterns in land cover, processes and yield/biomass.

The synoptic view and the repetitive cover afforded by satellite data allows multi-temporal observation of seasonal changes. To make best use of such information it is necessary to combine it with other data. The need for a marriage between remote sensing, earthbound survey, cartography and spatial and statistical analysis techniques is readily apparent and is made manifest through the adoption of GIS and databases within all crop assessment methodologies. These systems and methodologies represent an essential tool for the enhancement of traditional management techniques and structures.

GISL Limited have gained substantial experience in the development and implementation of various crop assessment methodologies in various parts of the world (Sudan, Ethiopia, Somalia) where early warning and food security information systems are vital in the adoption of responsible strategies to alleviate food insecurity and hunger.

GISL Limited staff have also been involved with institutional aspects of EU agricultural monitoring programmes and of agricultural improvement in the Russian Federation. These include procedures developed and revised by the EU under both the MARS programme and as part of the Integrated Administration and Control System (IACS) for the Common Agricultural Policy (CAP). Such programmes are integral to national economic policy as well as to national and international trade, pricing, competition and tariffs; as such it is not just the farmers but also the civil servants and politicians who have to have the facts (and the maps) at their fingertips to facilitate cogent and cost-effective decision making.

The development of the IACS is recognition enough of the billions of ECUs being spent by the EU every year on agricultural subsidy; that it has required the evolution of sophisticated techniques and the acquisition of large and costly volumes of remotely sensed data is indicative of the importance of remote sensing and GIS to the economies and agriculture of Europe. Such systems are now being introduced to former Eastern-bloc countries as their agriculture becomes increasingly intensive and competitive.

The development of single crop systems for forecasting for "the markets" is a natural step from the national agricultural monitoring programmes; being able to monitor discrete crops from planting through emergence to harvesting allows the buyers and sellers to be more responsive to crop and climatic conditions. Such techniques, when developed for other crops such as tea, coffee, cotton and cocoa and subsequently for cereals should also assist developing world economies in obtaining a fair price for their produce.

GISL Limited have associates who have working experience of either JRC or on FEOGA; Further, James Cutler and Justin Saunders, as directors of GISL Limited, have appropriate expertise in the development and implementation of operational methodologies in the mapping, assessment and monitoring of crop and biomass data using remotely sensed data. This includes establishment of early warning and food information systems in Sudan and Namibia, crop assessment in Ethiopia, Somalia, Morocco and Azerbaijan as well as studies of low-resolution satellite data in the Sahel. Such a diverse knowledge and understanding of remote sensing techniques is vital to their development and adoption on a wider scale.