تحليل الجفاف باستخدام المؤشر القياسي لهطول المطر (ٍSPI)‎ و مؤشر الجفاف الاستطلاعي RDI في محافظة النجف للمدة (1978-2018)‎

Abstract EN

Drought is one of the main causes of desertification.

This phenomenon can be attributed to insufficient seasonal rainfall, a prolonged dry season or a series of mediocre rainy season.

The main feature of drought is the low availability of water in a certain period over a certain area, which leads to a situation A sharp drop in water availability and shortages can extend over a significantly long period.

Accordingly, it was found that the direct impact of desertification on land degradation is either a decrease in land productivity or a complete abandonment of agricultural land, which ultimately leads to a food crisis in many arid and semi-arid regions.

There is a direct relationship between drought, desertification and food security, as these environmental risks lead Decreased soil quality leads to reduced agricultural productivity and ultimately drought, which is one of the main determinants of food security.

Drought and desertification lead to degradation of fertile land through long-term changes in soil, climate and biota, leading to desert-like conditions.

There are many indicators for measuring drought and its severity, including the Palmer Drought Index, the Standard Precipitation Index (SPI), and the Reconnaissance Drought Index (RDI).

Simple indicators (SPI and RDI) are much better than using complex hydrological indicators, and they are the simple and most effective methods for studying climatology.And drought, where these indicators have been widely adopted in recent years because of their computational simplicity and sincerity in interpretation to represent drought, and the drought results showed that both indicators show behavior similar in general to drought values, but the difference between them is that the RDI includes evaporation / transpiration and rain data in its calculation As for the SPI index, it depends only on rainfall, and this is what made the RDI index very sensitive to climate change, and this is somewhat important for detecting drought years, because RDI is more sensitive than SPI to climatic conditions, and therefore we cannot ignore the role of evaporation in drought assessments.

The RDI is suitable for water planning and management for the purpose of drought monitoring, and is universally applicable compared to other drought-related indicators.