Studies on identification indices of drought resistance by principal component analysis (PCA) indicated that germination rate and final emergence were most important and better indicators of establishment in rapeseed.
To investigate the physiological difference in DT of three genotypes, several indices of drought-induced effects on leaves at the tillering stage were measured.
In extreme summer conditions BIOME-BGC's soil moisture variable closely matches the Keetch Byram index of soil drought, and has the advantage of being sensitive to changing vegetation demands on soil water.
The proposed method adapts Standard Precipitation Index (SPI) methodology of drought classification by employing gamma mixture model (Gamma-MM) in a Bayesian framework.
Consequently, it is more directly related than existing indices, to potential drought impacts on different segments of society, and is also suitable to use as an index for drought insurance programs targeted at farmers growing specific crops.
For example, in a PSP with smallholder farmers in Malawi, insurance firms have developed an adverse climate/weather insurance system based on indexing historical records of drought.
This study clearly demonstrate the impacts of dataset selection on sensitivity of drought index computation, which has significant implications for proper usage of drought indices and related assessments, and potentially provide some valuable references for future researches on drought indices improvements.
In addition, it is found that the introduction of the self-calibrating procedure for duration factors further aggravates the dependence of drought index on input datasets compared with original empirical algorithm that Palmer uses, making SC-PDSI more sensitive to variations in data sample.
As another example, general growth habits such as culm length, panicle number, fertility ratio or dry matter weight each measured under drought stress conditions are often used as an index of the degree of drought resistance.
Our results are a robust assessment of the sensitivity of drought indices to P and ETo variation, and provide advice on the use of drought indices to detect climate change impacts on drought severity under a wide variety of climatic conditions.
