Search results

The purpose of this paper is to present the development of cumulative rainfall deficit (CRD) indices for corn in Shandong Province, China, based on high-resolution weather (county, 1980-2011) and yield data (township, 1989-2010) for five counties in Tai’an prefecture.

A survey with farming households is undertaken to obtain local corn prices and production costs to compute the sum insured. CRD indices are developed for five corn-growth phases. Rainfall is spatially interpolated to derive indices for areas that are outside a 25 km radius from weather stations. To lower basis risk, triggers and exits of the payout functions are statistically determined rather than relying on water requirement levels.

The results show that rainfall deficits in the main corn-growth phases explain yield reductions to a satisfying degree, except for the emergence phase. Correlation coefficients between payouts of the CRD indices and yield reductions reach 0.86-0.96 and underline the performance of the indices with low basis risk. The exception is SA-Xintai (correlation 0.71) where a total rainfall deficit index performs better (0.87). Risk premium rates range from 5.6 percent (Daiyue) to 12.2 percent (SA-Xintai) and adequately reflect the drought risk.

This paper suggests that rainfall deficit indices can be used in the future to complement existing indemnity-based insurance products that do not cover drought for corn in Shandong or for CRD indices to operate as a new insurance product.

The design and pricing of weather‐based insurance instruments is strongly based on an implicit assumption that the dependence structure between crop yields and weather variables remains unchanged over time. The purpose of this paper is to verify this critical assumption by employing historical time series of weather and farm yields from a semi‐arid region.

The analysis employs two different approaches to measure dependence in multivariate distributions – the regression analysis and copula approach. The estimations are done by employing Bayesian hierarchical model.

The paper reveals statistically significant temporal changes in the joint distribution of weather variables and wheat yields for grain‐producing farms in Kazakhstan over the period from 1961 to 2003.

By questioning its basic assumption the paper draws attention to serious limitations in the current methodology of the weather‐based insurance design.

The empirical results obtained indicate that the relationship between weather and crop yields is not fixed and can change over time. Accordingly, greater effort is required to capture potential temporal changes in the weather‐yield‐relationship and to consider them while developing and rating weather‐based insurance instruments.

The estimation of selected copula and regression models has been done by employing Bayesian hierarchical models.

The purpose of this paper is to review research on weather index insurance (WII) for mitigating the weather risk in agriculture and to identify research gaps in current available literature through integrative review.

This paper is based on the integrative review method as proposed by Whittemore and Knafl. QualSysts tool was adopted for assessing the quality appraisal of articles. Reporting followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

Detailed critical analysis of content reveals that WII studies are growing and shifting from traditional to the newest themes. Efficacy of WII is significantly influenced by the impacts of climate change. This paper generates a conceptual framework by synthesizing the published literature on WII.

This paper will be used to improve the WII practices and influence public policy. It is also beneficial in research by contributing to the systematic body of knowledge and useful for researchers to analyze the past and present status with future prospects of further studies on WII.

The paper is the original work of the author. To the best of authors’ knowledge, this is the first paper on integrative review on the efficacy of WII. An attempt has been made in the current paper to critically examine the studies of WII.

Examine the usability of rainfall and temperature outputs of a regional climate model (RCM) and meteorological drought indices to develop a macro-level risk transfer product to compensate the government of Central Java, Indonesia, for drought-related disaster payments to rice farmers.

Based on 0.5° gridded rainfall and temperature data (1960–2015) and projections of the WRF-RCM (2016–2040), the Standardized Precipitation Index (SPI) and the Standardized Precipitation Evapotranspiration Index (SPEI) are calculated for Central Java over different time spans. The drought indices are correlated to annual and seasonal rice production, based on which a weather index insurance structure is developed.

The six-month SPI correlates best with the wet season rice production, which generates most output in Central Java. The SPI time series reveals that drought severity increases in future years (2016–2040) and leads to higher payouts from the weather index structure compared to the historical period (1960–2015).

The developed methodology in using SPI for historical and projected periods allows the development of weather index insurance in other regions which have a clear link between rainfall deficit and agricultural production volatility.

Meteorological drought indices are a viable alternative for weather index insurance, which is usually based on rainfall amounts. RCM outputs provide valuable insights into future climate variability and drought risk and prolong the time series, which should result in more robust weather index insurance products.

The Monsoon Asian region has a much wider rainfall distribution than other regions of the world. The countries in this region are characterized mostly by floods and typhoons, which result from the interplay among the ocean, the atmosphere, and the land. Thus, many factors affect the strength of the rainfall, including sea surface temperatures in the Indian and Pacific Oceans, variations in solar output, land snow cover and soil moisture over the Asian continent, and the position and strength of prevailing winds. The links between these factors and monsoons appear to wax and wane over time, and the observational record is too short to explain this longer-term variability. Precipitation and surface wind maps of Asia during the summer months of June to August show the average spatial patterns of monsoon circulation and moisture.

Three Coupled Model Intercomparison Project Phase 5 models involved in the G4 experiment of the Geoengineering Model Inter-comparison Project (GeoMIP) project were used to investigate the impact of stratospheric aerosol injection (SAI) on the mean surface air temperature and precipitation extremes in Africa.

This impact was examined under G4 and Representative Concentration Pathway (RCP) 4.5 scenarios on the total precipitation, the number of rainy days (RR1) and of days with heavy rainfall (R20 mm), the rainfall intensity (SDII), the maximum length of consecutive wet (CWD) and dry (CDD) days and on the maximum rainfall in five consecutive days (Rx5day) across four regions: Western Africa (WAF), Eastern Africa (EAF), Northern Africa and Southern Africa (SAF).

During the 50 years (2020–2069) of SAI, mean continental warming is −0.40°C lower in G4 than under RCP4.5. During the post-injection period (2070–2090), the temperature continues to increase, but at a lower rate (−0.19°C) than in RCP4.5. During SAI, annual rainfall in G4 is significantly greater than in RCP4.5 over the high latitudes (especially over SAF) and lower over the tropics. The termination of SAI leads to a significant increase of rainfall over Sahel and EAF and a decrease over SAF and Guinea Coast (WAF).

Compared to RCP4.5, SAI will contribute to reducing significantly regional warming but with a significant decrease of rainfall in the tropics where rainfed agriculture account for a large part of the economies. After the SAI period, the risk of drought over the extratropical regions (especially in SAF) will be mitigated, while the risk of floods will be exacerbated in the Central Sahel.

To meet the Paris Agreement, African countries will implement mitigation measures to contribute to keep the surface air temperature below 2°C. Geoengineering with SAI is suggested as an option to meet this challenge, but its implication on the African climate system needs a deep investigation in the aim to understand the impacts on temperature and precipitation extremes. To the best of the authors’ knowledge, this study is the first to investigate the potential impact of SAI using the G4 experiment of GeoMIP on temperature and precipitation extremes of the African continent.

The purpose of this paper is to investigate the patterns and trends of drought incidence in north east highlands of Ethiopia using monthly rainfall record for the period 1984-2014.

Standard precipitation index and Mann – Kendal test were used to analyze drought incident and trends of drought occurrences, respectively. The spatial extent of droughts in the study area has been interpolated by inverse distance weighted method using the spatial analyst tool of ArcGIS.

Most of the studied stations experienced drought episodes in 1984, 1987/1988, 1992/1993, 1999, 2003/2004 and 2007/2008 which were among the worst drought years in the history of Ethiopia. The year 1984 was the most drastic and distinct-wide extreme drought episode in all studied stations. The Mann–Kendal test shows an increasing tendencies of drought at three-month (spring) timescale at all stations though significant (p < 0.05) only at Mekaneselam and decreasing tendencies at three-month (summer) and 12-month timescales at all stations. The frequency of total drought was the highest in central and north parts of the region in all study seasons.

This detail drought characterization can be used as bench mark to take comprehensive drought management measures such as early warning system, preparation and contingency planning, climate change adaptation programs.

This paper seeks to address the issue of persistent and widespread drought conditions during 2000 and 2001, which were the apparent cause of the decline of water levels in the reservoirs of Brazilian hydroelectric power plants.

This issue is addressed here through a case study of the hydroclimatology of the Paraíba river basin, in Southeast Brazil, home to four large multi‐purpose operational reservoirs.

The data analysis shows that neither changes in the frequency nor magnitude of extreme hydrological events (droughts and floods) nor in annual rainfall amounts can be detected from the existing climate record. The explanation is consistent with the fact that the terrestrial water and energy cycles are tightly, and non‐linearly, coupled through evapotranspiration.

Therefore small change in the seasonality of rainfall can have a significant impact on the basin's overall hydrologic regime, and thus on the availability of water resources.

Often, adaptation and resilience to climate variability are discussed in the context of catastrophic events such as floods and droughts. This study suggests that a different type of impacts, those associated with subtle, yet persistent changes of seasonality in the terrestrial water cycle, cannot be ignored in studies of long‐term sustainability of water resources.

This paper attempts to understand how the interaction of natural disasters and human behaviour during wartime led to famines in three regions under imperial control around the Indian Ocean. The socio-economic structure of these regions had been increasingly differentiated over the period of imperial rule, with large proportions of their populations relying on agricultural labour for their subsistence.

Before the war, food crises in each of the regions had been met by the private importation of grain from national or overseas surplus regions: the grain had been made available through a range of systems, the most complex of which was the Bengal Famine Code in which the able-bodied had to work before receiving money to buy food in the market.

During the Second World War, the loss of control of normal sources of imported grain, the destruction of shipping in the Indian Ocean (by both sides) and the military demands on internal transport systems prevented the use of traditional famine responses when natural events affected grain supply in each of the regions. These circumstances drew the governments into attempts to control their own grain markets.

The food crises raised complex ethical and practical issues for the governments charged with their solution. The most significant of these was that the British Government could have attempted to ship wheat to Bengal but, having lost naval control of the Indian Ocean in 1942 and needing warships in the Atlantic and Mediterranean in 1943 chose to ignore the needs of the people of Bengal, focussing instead on winning the war.

In each of the regions governments allowed/encouraged the balkanisation of the grain supply – at times down to the sub-district level – which at times served to produce waste and corruption, and opened the way for black markets as various groups (inside and outside government ranks) manipulated the local supply.

People were affected in different ways by the changes brought about by the war: some benefitted if their role was important to the war-effort; others suffered. The effect of this was multiplied by the way each government ‘solved’ its financial problems by – in essence – printing money.

Because of the natural events of the period, there would have been food crises in these regions without World War II, but decisions made in the light of wartime exigencies and opportunities turned crises into famines, causing the loss of millions of lives.

Vietnam is located in the tropical monsoon area, one of five storm hubs of Pacific Asia, and is regularly faced with various disasters. Drought, a normal part of the climate for virtually all regions of Vietnam, is of particular concern, where an interruption of the country already limited water supplies for extended periods of time can produce devastating impacts. Historical records indicate that drought occurs almost everywhere in those places almost every year (Hieu, 2002). However, multiyear droughts are of great concern to water-resource managers, natural-resource managers, and policy makers (Nguyen, 2010b).