Evaluation of hydro-meteorological drought indices for characterizing historical and future droughts and their impact on groundwater

Abstract

The effect of meteorological and hydrological droughts is very important in arid and semi-arid regions. Analyzing these effects on groundwater supplies plays an important role for water management in those regions. This paper aims to characterize droughts in the Isfahan-Borkhar basin, an arid area of Iran. The observed hydro-climatic data (for the period of 1971-2005) were used for hydro-meteorological projections (for the period of 2006-2040). Meteorological and surface hydrological drought evaluated by Standardized Precipitation Index (SPI), Standardized Runoff Index (SRI), and the effect of hydro-meteorological droughts on groundwater was investigated by Groundwater Resources Index (GRI). Results showed that dry and wet conditions would occur in the region in the initial and subsequent decades, based on the three indices. There was a significant association between SPI, SRI, and GRI at the time scale of 12 months. The SPI estimated using only meteorological variables alone and it is useful for estimating meteorological drought forecasts. However, SRI and GRI can represent hydrological drought that computed using catchment discharge, soil moisture and groundwater level. Results showed a considerable alteration in time of drought outlines across the area and association between the variables of predicted precipitation, temperature and the kind of indices. The projection of all three drought indices indicated drier conditions in the future period (2006-2042). The results provide reasonable management strategy for management of water resources in arid coastal plains.

Droughts and the Impacts of Dry Spells in North of Iraq

“…The definition of dry spells based on the length of days without precipitation has been widely used in many climatological studies. The advantage of using these definitions and similar definitions is one in determining the thresholds and the other in facilitating the use of specific statistical analyzes for studying dry spells with different continuations [26], [27], [28], [29] . Several methods have been used to study the behavior of wet and dry spells.…”

Runoff coefficient estimation for various catchment surfaces

“…During high base flow circumstances, using total flow can cause higher runoff coefficients. Sometimes, the runoff coefficient in this condition is known as water yield [18,19] introduced the runoff coefficient as new water contributing portion of a watershed.…”

Investigation of water quality in wet and dry seasons under climate change

“…The average annual potential evapotranspiration is approximately 2400 mm (Figure 1). The unconfined aquifer of Isfahan-Borkhar basin is located in the Isfahan province [17]. Based on the structure-sedimental zoning of Iran, the Isfahan-Borkhar basin is located in the Sanandaj-Sirjan sub-zone in the central region of Iran.…”