Catálogo de publicaciones - libros

Natural disasters play a major role in agricultural development and the economic cost associated with all natural disasters has increased 14 fold since the 1950s. Natural disasters are classified into hydro-meteorological and geophysical disasters. Definitions of various types of hydrometeorological disasters such as floods, droughts, cyclones, forest fires, heatwaves were presented. Evidence available from different parts of the world showed that there is a rising trend in the occurrence of natural disasters from 1993 to 2002. Impacts of droughts, cyclones, floods, forest and bush fires on agriculture, rangeland and forestry were described with suitable examples. While the predominant impacts from these disasters are negative, there are some positive impacts as well. Environmental degradation is one of the major factors contributing to the vulnerability of agriculture, forestry and rangelands to natural disasters because it directly magnifies the risk of natural disasters. Some methodological issues concerning the characterization of the impacts of natural disasters in agriculture, rangeland and forestry were described. There is an urgent need to mitigate the effects hydro-meteorological disasters through improved use of climate and weather information and forecasts, early warning systems, and appropriate methods of management of land and natural resources.

Drought is a slow-onset, insidious natural hazard. Vulnerability to drought is increasing in all drought-prone nations and the traditional crisis management approach to address the impacts of these events has proven to be ineffective, untimely, and poorly coordinated. Amore risk-based management approach has been gaining acceptance worldwide because it addresses the underlying cause of impacts — vulnerability. This approach includes development of national policies and mitigation plans directed at identifying the causes of drought impacts and improved early warning systems that provide information to decision makers in a timely manner. This paper discusses the conceptual framework for improved drought preparedness planning with an emphasis on reducing societal vulnerability to future episodes of drought.

Extreme events in the Southwest Pacific (SWP) are widespread and largely centre on tropical cyclones, droughts and floods. These events are directly influenced by the state of the El Niño Southern Oscillation (ENSO). The impacts of climate extremes are dramatic, particularly on Small Island Developing States (SIDS) of the SWP region. They cause destruction and widespread damage to human, socio, economic and development well being of local communities, examples being tropical cyclones Ofa, Val and more recently Heta, Olaf and Percy that devastated Samoa, Niue, Tonga and the Cook Islands and the severe impacts of the 1997–1998 El Niño event on Papua New Guinea and Fiji. Although warming in the SWP region is decreasing, extremes of low temperature, the trend of more El Niño episodes in the 20th century, based on observations, has increased both dry periods and extreme rainfalls in significant parts of the region, especially near the Date Line. The phase of ENSO also significantly affects temperature and rainfall anomalies and extreme across the region, with sharp gradients between contrasting areas of above and below average departures. ENSO also changes tropical cyclone track, density and occurrence, with El Niño events increasing the frequency and displacing tropical cyclones more towards the central South Pacific, and La Niña episodes decreasing the frequency and confining tracks to the west of the Date Line. Seasonal to Inter-annual (SI) prediction has become a major research area and application tool that offers much promise for early warning and disaster preparedness to extreme events. In the SIDS of the SWP region, the Island Climate Update (ICU), a multinational virtual type regional climate prediction tool, with success hit rates (percentage of prediction being correct after comparing it with what actually happened) greater than 70 percent being achieved in some parts of the region since it was launched in September 1999, provides an extremely useful regional mechanism for preparing and predicting seasonal rainfall departures and other extreme events associated with ENSO for SIDS. The ICU could be used as a model in other regions.

Extreme events can cause severe damage in several sectors such as agriculture, forests and fisheries. In order to facilitate early detection of these harmful episodes, adequate climate and agrometeorological databases must be ensured. Some observational data and products necessary for early detection are presented in this paper. It briefly reviews the main features of proper databases that provide quality controlled data and products, useful to the end-users, easily accessible and in a timely manner. The data can be accessed through the standardization of database management and electronic accessibility. The main features and importance of data collection, automatic weather stations (AWS), database management and relational database management systems (RDBMS) are described. Examples of agrometeorological databases, database management systems and their applications and accessibility are given. Remote sensing (geostationary satellites, NOAA-Advanced Very High Resolution Radiometer (AVHRR), radar and lighting detectors) offers a valuable source of spatial information and can be complementary or even alternative to ground-based observations. Due to the processing of data from various sources in agrometeorology, and the need to display them in maps, geographical information systems (GIS) are in wider use today. GIS can help to identify the risk, extent and severity of many extreme events. Some examples of applications of remote sensing and GIS are presented. Finally, training, interdisciplinary collaboration and communication between users and developers of products are referred as essential means to achieve these goals.

Disasters induced by natural disasters carry significant consequences for agriculture, forestry and fishery sectors. In this paper, an attempt was made to give a brief account of tools available for forecasting or warning of natural disasters including floods, droughts, tropical cyclones, forest fires, and volcanoes. Use of such tools is important to decrease the impact on natural disasters on agriculture and forestry. Amongst the most well known predictions schemes is the El Niõ — Southern Oscillation (ENSO). This and other prediction tools have been discussed with suitable examples.

Agricultural production is highly dependent on weather, climate and water availability and is adversely affected by the weather and climate related disasters. Impacts of extreme events on the agricultural sector can be positive or negative. While it is easier to contemplate negative impacts of extreme events such as droughts, tropical cyclones and floods, there are several positive impacts or benefits of extreme events. In order to assess the impact of weather disaster on agriculture, one must link two fundamental aspects, first, the disaster proper i.e. the destructive power of the event and secondly, the characteristics of the agricultural system which has been hit. Agricultural planning and practices need to be worked out with consideration to the overall water requirements within an individual agroclimatic zone. Sustainable strategies must be developed to alleviate the impact of natural disasters on crop productivity. All such strategies are location, time, crop, crop stage and socio-economic condition specific. Remote sensing satellite information helps minimise damages e.g. the death of cattle, humans etc. and the damage of agricultural production in time of natural calamities by early warning system.

Damage from catastrophic events is both social and economic. Perhaps one of the most challenging aspects of modern life is our increasing ability to communicate, especially in the developed countries. This communication has brought an increased sense of connectedness but also made people more aware of the occurrence and consequences of natural disasters. In this paper we explore the potential for changes in frequency and magnitude of weather-related natural disasters and some of their connections to climate change and variability. Although changes in climate may have great consequence, increasing climate variability may become the most immediate challenge for world society. Both observations and simulation models show that as the potential for climate variability increases, natural disasters have become more frequent and of deeper economic impact. In areas of the world where these devastating events appear to occur and then quickly reoccur in a different guise, the sharing of information and resources becomes a pivotal issue for collective security. New technologies can help us understand these events and prepare for them. New social institutions may also be needed to cope with these issues on a global scale.

Tropical cyclones are perhaps the most devastating of all natural disasters and the vulnerability to tropical cyclones is becoming more pronounced because of high population growth rates in the tropical and subtropical coastal regions. Tropical cyclones cause a range of destruction in the coastal areas. Various features of tropical cyclones affecting China and their impacts on lowland agriculture and coastal fisheries were described.

Frost and high temperature injury are two important agrometeorological disasters in China. In this paper, the concept of frost and its differences from other low temperature injuries are presented. Recent studies on injury mechanism of frost are introduced. Frost-prone areas, crops harmed, and statistical characteristics in China are analyzed and summarized. Frost preventive and preparedness measures in China are discussed. The detrimental impacts of high temperature injury on crops, vegetables, fruit trees, milk yield, livestock, and fish in China are also briefly reviewed.

The drylands of the world are affected by moderate to severe land degradation from wind erosion and there is evidence that the frequency of sand storms/dust storms in increasing. Human induced change is by far the most significant factor in the alarming increase of sand storms in some regions. The definition of sand storms and dust storms were presented and the classifications currently in use were discussed. The occurrence of wind erosion at any place is a function of weather events interacting with soil and land management through its effects on soil structure, tilth and vegetation cover. The mechanics of sand and dust storms and their spatial and temporal distribution was described. The impacts of sand and dust storms were described in terms of crop damage, soil productivity losses, economic losses, mass migration, health impacts, and impacts on climate. Not all the impacts are negative and the positive impacts of sand and dust storms were described. Measures to combat sand and dust storms include reduction of the impact of wind speed through the use of live wind breaks or shelterbelts; protection of the loose soil particles through the use of crop residues or plastic sheets or chemical adhesives; and increasing the cohesion of soil particles by mechanical tillage operations or soil mulching. Future strategies for reducing the impacts of sand storms and dust storms must be based on community-based approaches that integrate effective crop and land management strategies as well as policy interventions to promote more effective soil conservation measures at the national and regional scales.