Assessment values of the rainwater concentration index for some regions in the middle and southern Iraq using GIS

ABSTRACT The precipitation concentration index is one of the key measures used to determine the distribution and pattern of rainfall in every region. It is also used to monitor natural hazards such as floods and droughts. This research was conducted to assess and calculate the rainwater concentration index (RWCI) in the middle and southern regions of Iraq using the annual rainwater concentration index (ARWCI), and seasonally in winter (WRWCI), summer (SRWCI), spring (SPRWCI), and fall (FRWCI). In addition to this, the supra-seasonal rainwater concentration index was used in the dry season (DRWCI) and wet season (WERWCI) for seven stations (Basra, Basra-Air, Amara, Ali-Elgharbi, Nasiriya, Hai, and Badra) for 2005–2024. Geographical information system (GIS) software, an effective tool, was used to create a spatial distribution of rainwater indices using seasonally and yearly rainwater index data. The result demonstrated that ARWCI, WRWCI, SRWCI, SPRWCI, FRWCI, DRWCI, and WERWCI in all stations for all years range from moderate, uniform distribution to intense irregularity. Furthermore, statistical indices have values less than one. This is a good indicator of the quality of the RWCI values. These outcomes offer significant new perspectives for evaluating and regulating the region's agriculture and water resources, and assist in deciding about flood risk management in regions that receive considerable amounts of rainfall.