A Comparison of Different Interpolation Methods Using the Geographical Information System for the Production of Reference Evapotranspiration Maps in Turkey

Abstract

Eight different interpolation methods (inverse distance weighting, spline with tension, thin-plate spline, completely regularized spline, ordinary kriging, simple kriging, universal kriging, and linear regression (LR) model) were comparatively analyzed to determine the spatial distribution of monthly reference evapotranspiration (ET 0 ) values calculated using the Hargreaves method (ET 0-HG ). To compare the different methods, observation stations were divided into two data groups (58 stations for analysis and 14 stations for validation). The correlation coefficients for all months ranged between 0.68 and 0.90. Of all the methods evaluated, the LR model was found to give the optimum results. The highest correlation coefficient was observed with the LR model for all months except March, April, June, and September. UK showed lower correlation coefficients than the LR model for all months except June and September and was found to be the second-best method. Secondary data contributed positively to ET 0-HG interpolation; therefore, certain spatial data was incorporated into the LR model. The relationship between the monthly ET 0-HG values produced using the most efficient interpolation method, and the values calculated with the Penman-Monteith method (ET 0-PM ) were also investigated in this study. Correlation coefficients between the methods varied between 0.65 and 0.86 for all months. The largest difference between the two methods was observed in June (-2.27 mm day ). In conclusion, Hargreaves method was found to be easier to use in calculating ET 0 for the creation of ET 0 maps, in which the use of LR was found to be more reliable than other interpolation methods.

Changes in the Water Balance of Bosnia and Herzegovina as a Result of Climate Change

“…The slope (b) indicates the mean temporal change of the studied variable. Positive values of the slope show increasing trends, while negative values of the slope indicate decreasing trends (Gocic & Trajkovic, 2013, 2014.…”

“…The changes in the air temperature and the amount of precipitation results in changes in evapotranspiration (Cadro et al, 2019;Cadro et al, 2017) and the values of different soil water balance elements (Giugliano et al, 2013). Understanding the spatial and temporal variability of soil water balance elements such as evapotranspiration, water surplus, runoff, soil moisture deficit is essential for many hydrological, agricultural and environmental models (Guler, 2014;Huntington, 2006), especially in assessing regional climate change scenarios and natural hazards (landslides, floods, droughts, wildfires, disease epidemics, insect/animal plagues).…”

Estimation of Water Losses Through Evapotranspiration of Water Hyacinth (Eichhornia crassipes)

“…Increased water loss through evapotranspiration of water hyacinth is considered one of the most crucial weed problems in water bodies. Estimating reference evapotranspiration (ETo) has an important role in various aspects of research, such as the hydrological cycle, irrigation system, water resource management (Hou et al, 2013;Berti et al, 2014;Valipour, 2015;Zhao et al, 2015;Abdullahi and Elkiran, 2017;Zhang et al, 2018;Zhang et al, 2019), forest meteorology (Khoshravesh et al, 2015), flood risk assessment, drought analysis, environmental studies (Pandey et al, 2016;Čadro et al, 2018), as a model of assessment and climate change scenarios (Güler, 2014), economical allocation of water resources, increase of water use efficiency (Singh Rawat et al, 2019).…”

Spatial and Temporal Change of Reference Crop Evapotranspiration in Marmara Region

“…Değişen iklim koşullarında buharlaşma ve evapotranspirasyonun (ET) mekansal-zamansal eğilimlerinin analizi, özellikle tarımsal su kaynaklarının kullanımını iyileştirmek için önemlidir ve ekolojik ve çevresel su gereksinimlerinin mekansal-zamansal değişimini anlamak için yardımcı olur (Zuo vd., 2012). Dünya'da ve ülkemizde ETo değerlerinin mekânsal ve zamansal değişimi üzerine çalışmalar yapılmıştır (Altalib vd., 2021;Altındağ, 2007;Anlı, 2014;Bayramoğlu, 2013;Çetin, 2018;Güler, 2014;Jerin vd., 2021;Karaca vd., 2017;Mubialiwo vd., 2020;Ndiaye vd., 2020;Talaee vd., 2014;Xu vd., 2017;Yürekli vd., 2010;Zhang vd., 2018). Fakat ülkemizde bölgesel bazda Marmara Bölgesi'nde ETo'nin mekânsal ve alansal değişimini ele alan bir çalışmaya rastlanmamıştır.…”