Investigation of Changes in the Amount and Distribution of extreme precipitation and its effect on the trend of changes in the NDVI in southeast Iran

Articles in Press

Document Type : Applied Article

Authors

• Maede Nasry ¹
• Mohammad Rahimi ²
• Farzaneh Hadadi barforush ³
• Hadi Jalili ⁴
• Aliakbar Damavandi ⁵

¹ PhD in desert control and management, Combat to Desertification Department, Faculty of Desert Studies, Semnan University, Semnan, Iran.

² Combat to Desertification Department, Faculty of Desert Studies, Semnan University, Semnan, Iran

³ M.Sc. in Remote Sensing and GIS, Iranian Space Research Institute, Tehran, Iran

⁴ Iranian Space Research Institute, Tehran, Iran

⁵ Assistant Professor, Agricultural Education and Extension Institute, Agricultural Research, Education and Extension Organization (AREEO), Tehran, Iran

10.22067/jwsd.v12i1.2411-1381

Abstract

Extreme precipitation indices were selected using a fixed approach recommended by Expert Team on Climate Change Detection and Indices according to local needs and the climatic nature of the study area. These indices were extracted using daily precipitation data from the stations of the study area over 21 years from 2000 to 2020 using RclimDex software. The NDVI index of MODIS satellite images was used to analyze the trend of annual vegetation cover changes. Also, the multilayer Perceptron neural network method was used to examine the relationship between changes in extreme precipitation indices on vegetation cover changes. The results showed that the NDVI index has an increasing trend spatially from east to west of the region. Areas with low NDVI were observed in the eastern, southern, and northern parts and areas with high NDVI were observed in the western part of the study area. The highest NDVI index values were observed at Minab and Rodan stations with values of 0.21 and 0.19. The lowest average NDVI index was observed at Bam station with a value of 0.03. The trend of NDVI index changes was significant and upward only at Rodan station (P-value = 0.01) and Kahnouj (P-value = 0.0001). The trend of changes at Saravan, Iranshahr, Bandar Abbas, and Bam stations was upward but not significant. The trend of changes at Zabol, Chabahar, Minab, Khash, and Zahedan stations was negative and insignificant. The overall trend indicated an increase in precipitation extremes during the study period. .

Keywords

• Climate extreme
• Vegetation cover
• Artificial Neural Network
• Satellite image

Main Subjects

• Risk, Sustainability and Resilience