Spatial ranking of paddy rice cultivation areas using water footprint concepts and TOPSIS technique
摘要
The purpose of this study is to prioritize paddy rice cultivation in Iran based on rice water use efficiency (WUE), water footprint (WF), the economic value of water footprint (EVWF), and economic land value (EVL) using the TOPSIS technique. The average WF, EVWF, EVL, and WUE of paddy rice in Iran were estimated at 2297.6 m3/ton, 0.45 USD/m3, 3731.25 USD/ha, and 0.39 m3/kg, respectively. The results of the study revealed that rice production in Iran benefited minimally from green water, contributing only 4.3% on average. In contrast, the majority of water resources utilized in rice production were derived from blue water (87%), highlighting a heavy reliance on irrigation and limited use of rainfall across most regions. At the regional scale, the highest water footprint in rice production was observed in southeastern Iran, in the province of Sistan and Baluchistan (3201.6 m³/ton), which also had the lowest water use efficiency (WUE) at 0.22 m³/kg. Conversely, Mazandaran province in the north recorded the lowest water footprint (1007.9 m³/ton) and the highest WUE (1.09 m³/kg). The most important criteria for prioritizing rice cultivation areas were effective rainfall, green and blue water footprint, and crop water requirement, as these factors directly influence water sustainability and the efficiency of agricultural practices in water-scarce regions. According to the TOPSIS ranking, the northern regions of Iran (the provinces of Mazandaran and Guilan) were identified as the top priority for rice cultivation, while most of the current rice-growing areas were classified as unsuitable for rice production. Given the climatic conditions and limited water resources in most rice-growing areas of the country, the indicators presented in this study provide a practical framework for decision-making, enabling the efficient allocation of land, water, and financial resources to optimize rice cultivation.