Analysis of the observed trends in daily extreme precipitation indices in Gaza Strip during 1974–2016

Abstract

There is a high‐risk attendant on the changes in precipitation in developing countries, for example, Gaza Strip (GS). These changes have far‐reaching social and economic ramifications by causing devastating flash floods and droughts. Based on the daily precipitation observations of eight meteorological stations over GS, from 1974 to 2016, the trends of 11 extreme precipitation indices (EPIs) were estimated using linear least squares method and then assessed statistically by Mann‐Kendall test. The results show that, on average, most of the indices exhibited increasing trends during 1974–2016. It includes total wet‐day precipitation (PRCPTOT), simple daily intensity index (SDII), and max 1‐day precipitation (RX1day). Others were the max 5‐day precipitation (RX5day), very wet day precipitation (R95p), extremely wet day precipitation (R99p), number of heavy precipitation days (R10mm), number of very heavy precipitation days (R20mm), and the number of consecutive dry days (CDD). Three of these indices passed the significance test (with p < .05): RX1day, RX5day, and R95p. Other EPIs, including number of wet days (R1mm) and consecutive wet days (CWD), exhibited non‐significant decreasing trends. Spatially, many stations over GS exhibited opposite trends, especially in R1mm and CDD; however, they are separated by a few kilometres. Moreover, all EPIs have significant positive correlations with PRCPTOT at the 99% confidence level, except CDD (trend was non‐significant). The contribution of extreme precipitation to annual PRCPTOT exhibited an increasing trend, which was significant at 62% of GS stations. The study indicates a potential increase in summer (drought) season.

Variation in Seasonal Precipitation over Gaza (Palestine) and Its Sensitivity to Teleconnection Patterns

“…The dramatic situation of water resources in Gaza makes it vital to understand the reasons behind this situation. Previous literature considered Gaza water scarcity with engineering methods [11,34]; however, attention should be drawn to a discursive analysis that helps understand the causes of the water scarcity problem and how to solve it [35][36][37]. The current dominant discourse of water scarcity in Gaza includes two narratives: insufficient water resources and lack of fund.…”

“…The insufficiency narrative emphasizes that Gaza is a small region with a very high population density and minimal water resources (see study area description-Section 1.1). This narrative also includes the negative impact of climate change on water resources [11]. The second narrative (lack of fund) indicates that the water scarcity problems did not receive adequate fund.…”

“…Ziv, et al [10] noticed a negligible trend in the Gaza region vicinity. Ajjur and Riffi [11] examined the trends in 11 extreme precipitation indices in the Gaza region. Most indices increased after the 1980s.…”

“…Total precipitation, for example, has risen over two periods 1985-2004 and 2009-2016. The source of variations in the extreme precipitation metrics in [11] is still unknown. These variations seem to be organized in coherent temporal patterns that suggest two options.…”

“…Regrettably, floodwater is not utilized either, in agriculture, although it makes abundant freshwater available. Seasonal drought is frequent in the region [11]. There is a need to recharge the aquifer in the Gaza region, which is the primary source of water.…”