Relationship between drought and solar irradiation variables

Abstract

Abstract:Drought prediction for in many regions of the world has critical importance for strategic planning agriculture and water management. The occurrence of droughts cannot be predicted with certainty and thus must be treated as random variables. It is the main purpose of this paper to develop a new concept of drought features assessments based on triple drought related hydrometeorological and meteorological variables, namely, rainfall, solar irradiation and sunshine duration. Equal standard rainfall lines are drawn as a map with two reference variables as solar irradiation and sunshine duration. These are referred to as the triple graphical method (TGM) approach. It furnishes rich features of drought behaviour variation based on the rainfall, solar irradiation and sunshine duration. This analysis and the solar irradiation estimation method are applied to seven climatologically different stations in the Republic of Turkey for the monthly data period 1982-1991. The linear relations between drought and the variables of the Angström equation are found between 55% and 94% without Trabzon. Drought and Angström equation parameters are estimated by the proposed methodology. Relations between monthly drought and Angström equation variables are presented by the triple solar-drought graphical method. TGM provides information about the drought occurrences for different combinations of solar irradiation and sunshine duration. TGM graphs help to identify not only precipitation surplus (wet spells) or deficits (dry spells droughts) but also their variations with two more meteorological variables as solar irradiation and sunshine duration.

Comparison of multi-monthly rainfall-based drought severity indices, with application to semi-arid Konya closed basin, Turkey

“…Z-Score is frequently computed in drought studies (Akhtari et al, 2009;Komuscu, 1999;Morid et al, 2006;Patel et al, 2007;Tsakiris and Vangelis, 2004;Wu et al, 2001). To differentiate it from SPI, Z-Score is sometimes called the standardized monthly precipitation (SMP) (Sirdas and Sahin, 2008). Since the original SPI (Mckee et al, 1993) has been commonly used to fit a gamma distribution, calling as Z-Score or SMP instead of SPI for further studies is better when the distribution type is normal.…”

The implications of geography and climate on drought trend

“…The Z ‐score for SPI trend significantly decreased in regions with low elevation and high solar radiation in the short‐, seasonal‐, and medium‐term drought durations for the spring months of April and May. Sirdas and Sahin () have shown that solar radiation and sunshine duration both increases drastically during the dry seasons, whereas solar radiation is the lowest during the wet seasons. In addition, the study demonstrated that the sunshine duration during the dry seasons has a significant effect on droughts.…”

Climatological Drought Analyses Using SPI, Deciles, PPN, EDI and Rainy Days in Chile

“…As well as the Deciles Precipitation Index, the Effective Drought Index (EDI), and the SPI, their values are standardized; which allows detailed comparison between regions with different climates (Byun andWilhite 1999, Danandeh et al 2019). Because the prediction of drought periods is of high importance for water planning around the world, forecasting models must become more robust and simple (Sirdas and Sahin 2008).…”

“…Any proposed index would include loss of soil moisture, change in groundwater storage or decrease in reservoir levels (Zargar et al 2011, Van Loon andLaaha 2015) as the main inputs. Because the occurrence of droughts cannot be predicted with certainty, it should be studied as a random variable (Sirdas and Sahin 2008).…”