Multivariate analysis of evaporation drivers in Mbeya, Tanzania, using principal component analysis

Evaporation is a vital process in the hydrological cycle, accounting for approximately 70% of water loss from the Earth’s surface. In semi-arid and rapidly urbanizing regions, such as Mbeya, Tanzania, understanding the meteorological drivers of evaporation is critical for water resource management and agricultural planning. This study utilized principal component analysis (PCA) on a 10-year dataset comprising solar radiation, sunshine hours, minimum and maximum temperatures, and wind speed to identify key factors influencing evaporation. Descriptive statistics revealed significant non-normality in most variables, particularly radiation and wind speed. At the same time, correlation analysis showed a strong positive relationship between sunshine hours and radiation (r= 0.66) and a moderate negative correlation between radiation and minimum temperature (r= −0.30). PCA identified two principal components accounting for 66.61% of the total variance. Component 1 (38.06%) captured solar-driven variability, dominated by sunshine duration and radiation, whereas Component 2 (28.55%) reflected thermal influences, particularly maximum and minimum temperatures. Wind speed contributed minimally, suggesting a more localized or less consistent role in evaporation dynamics. These findings demonstrate the value of PCA in simplifying complex climatic datasets and improving the interpretation of evaporation processes. Solar radiation and sunshine hours emerged as the dominant drivers, with temperature as a secondary influence. The results emphasize the need to integrate surface-level variables, such as land use, vegetation cover, and soil moisture, in future studies to capture spatial heterogeneity and improve predictive accuracy, especially in data-scarce, climate-sensitive regions like Mbeya.
- Moges S, Katambara Z, Bashar K. Decision support system for estimation of potential evapo-transpiration in Pangani Basin. Phys Chem Earth Parts A/B/C. 2003;28(20-27):927-934. doi: 10.1016/j.pce.2003.08.038
- Fan J, Zheng J, Wu L, Zang F. Estimation of daily maize transpiration using support vector machines, extreme gradient boosting, artificial and deep neural networks models. Agric Water Manag. 2021;245:106547. doi: 10.1016/j.agwat.2020.106547
- Han Y, Calabrese S, Du H, Yin J. Evaluating biases in Penman and Penman-Monteith evapotranspiration rates at different timescales. J Hydrol. 2024;638:131534. doi: 10.1016/j.jhydrol.2024.131534
- Yonaba R, Tazen F, Cissé M, et al. Trends, sensitivity and estimation of daily reference evapotranspiration ET0 using limited climate data: Regional focus on Burkina Faso in the West African Sahel. Theor Appl Climatol. 2023;153(1):947-974. doi: 10.1007/s00704-023-04507-z
- Masson-Delmotte V, Zhai P, Pirani A, et al. Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change. Vol. 2. Cambridge: Cambridge University Press; 2021. p. 2391. doi: 10.1017/9781009157896
- Tsujimoto K, Masumoto T, Mitsuno T. Seasonal changes in radiation and evaporation implied from the diurnal distribution of rainfall in the Lower Mekong. Hydrol Process Int J. 2008;22(9):1257-1266 doi: 10.1002/hyp.69357
- Haddad K, Rahman A, Stedinger JR. Regional flood frequency analysis using Bayesian generalized least squares: A comparison between quantile and parameter regression techniques. Hydrol Process. 2012;26(7):1008-1021. doi: 10.1002/hyp.8189
- Wold S, Ruhe A, Wold H, et al. The collinearity problem in linear regression. The partial least squares (PLS) approach to generalized inverses. SIAM J Sci Stat Comput. 1984;5(3):735-743. doi: 10.1137/0905052
- Jolliffe IT, Cadima J. Principal component analysis: A review and recent developments. Philos Trans A Math Phys Eng Sci. 2016;374(2065):20150202. doi: 10.1098/rsta.2015.0202
- Ma J, Zhou L, Foltz GR, et al. Hydrological cycle changes under global warming and their effects on multiscale climate variability. Ann N Y Acad Sci. 2020;1472(1):21-48. doi: 10.1111/nyas.14335
- Cao W, Zhang SJ, Lu ZL, et al. Prediction for Water Surface Evaporation Based on PCA and RBF Neural Network. In: International Conference on Information Computing and Applications, Springer; 2011. p. 351-358. doi: 10.1007/978-3-642-25255-6_45
- James G, Witten D, Hastie T, Tibshirani R, Taylor J. Linear Regression. An Introduction to Statistical Learning: With Applications in Python. Berlin: Springer; 2023. p. 69-134.
- Ullah I, Ma X, Ren G, et al. Recent changes in drought events over South Asia and their possible linkages with climatic and dynamic factors. Remote Sens. 2022;14(13):3219. doi: 10.3390/rs14133219
- Jafari M, Dinpashoh Y. Derivation of regression models for pan evaporation estimation. Environ Resour Res. 2019;7(1):29-42.
- Tianxiao L, Qiang F, Shuqin X, et al. Application of Principal Component Analysis in Evaluating Influence Factors of Evaporation in Northern Cold Area. In: 2009 Fifth International Conference on Natural Computation: IEEE; 2009. p. 514-518. doi: 10.1109/icnc.2009.721
- Dupre K. Trends and gaps in place-making in the context of urban development and tourism: 25 years of literature review. J Place Manage Dev. 2019;12(1):102-120. doi: 10.1108/JPMD-07-2017-0072
- Gwaleba MJ. Urban growth in Tanzania: Exploring challenges, opportunities and management. Int J Soc Sci Stud. 2018;6:47. doi: 10.11114/ijsss.v6i12.3783
- Tanzania URo. The United Republic of Tanzania Agricultural Sector Development Programme (ASDP) Support through Basket Fund Government Programme Document; 2017.
- Liang S, Fang H, Chen M. Atmospheric correction of Landsat ETM+ land surface imagery. I. Methods. IEEE Trans Geosci Remote Sens. 2002;39(11):2490-2498. doi: 10.1109/36.964986
- Hubert M, Rousseeuw P, Verdonck T. Robust PCA for skewed data and its outlier map. Comput Stat Data Anal. 2009;53(6):2264-2274. doi: 10.1016/j.csda.2008.05.027
- Yang J, Ye M, Tang Z, et al. Using cluster analysis for understanding spatial and temporal patterns and controlling factors of groundwater geochemistry in a regional aquifer. J Hydrol. 2020;583:124594. doi: 10.1016/j.jhydrol.2020.124594
- New M, Lister D, Hulme M, et al. A high-resolution data set of surface climate over global land areas. Clim Res. 2002;21(1):1-25. doi: 10.3354/cr021001
- Nicholson SE. Climate and climatic variability of rainfall over eastern Africa. Rev Geophys. 2017;55(3):590-635. doi: 10.1002/2016RG000544
- Allen RG, Pereira LS, Raes D, Smith M. Crop Evapotranspiration-Guidelines for Computing Crop Water Requirements-FAO Irrigation and Drainage Paper no 56. Vol. 300. Rome: FAO; 1998. p. D05109.
- Antuña-Sánchez JC, Estevan R, Román R, et al. Solar radiation climatology in Camagüey, Cuba (1981-2016). Remote Sens. 2021;13(2):169. doi: 10.3390/rs13020169
- Noel DD, Justin KGA, Alphonse AK, et al. Normality assessment of several quantitative data transformation procedures. Biostat Biometr Open Access J. 2021;10(3):51-65. doi: 10.19080/BBOAJ.2021.10.5557786
- Przeździecki K, Zawadzki JJ, Urbaniak M, et al. Using temporal variability of land surface temperature and normalized vegetation index to estimate soil moisture condition on forest areas by means of remote sensing. Ecol Indic. 2023;148:110088. doi: 10.1016/j.ecolind.2023.110088
- Chang TP, Liu FJ, Ko HH, et al. Oscillation characteristic study of wind speed, global solar radiation and air temperature using wavelet analysis. Appl Energy. 2017;190:650-657. doi: 10.1016/j.apenergy.2016.12.149
- Chan JY, Leow SMH, Bea KT, et al. Mitigating the multicollinearity problem and its machine learning approach: A review. Mathematics. 2022;10(8):1283. doi: 10.3390/math10081283
- Stanhill G, Cohen S. Global dimming: A review of the evidence for a widespread and significant reduction in global radiation with discussion of its probable causes and possible agricultural consequences. Agric Forest Meteorol. 2001;107(4):255-278. doi: 10.1016/S0168-1923(00)00241-0
- Matuszko D, Węglarczyk S. Effect of cloudiness on long-term variability in air temperature in Krakow. Int J Climatol. 2014;34(1):145-154. doi: 10.1002/joc.3672
- Sarrat C, Lemonsu A, Masson V, Guedalia D. Impact of urban heat island on regional atmospheric pollution. Atmos Environ. 2006;40(10):1743-1758. doi: 10.1016/j.atmosenv.2005.11.037
- Rojas-Valverde D, Pino-Ortega J, Gómez-Carmona CD, et al. A systematic review of methods and criteria standard proposal for the use of principal component analysis in team’s sports science. Int J Environ Res Public Health. 2020;17(23):8712. doi: 10.3390/ijerph17238712
- Barnes KB, Morgan J, Roberge M. Impervious Surfaces and the Quality of Natural and Built Environments. Baltimore: Department of Geography and Environmental Planning, Towson University; 2001.
- Chen H, Huang JJ, Dash SS, McBean E, Wei Y, Li H. Assessing the impact of urbanization on urban evapotranspiration and its components using a novel four-source energy balance model. Agric For Meteorol. 2022;316:108853. doi: 10.1016/j.agrformet.2022.108853