Skip to main content
Log in

Estimating potential evapotranspiration based on self-optimizing nearest neighbor algorithms: a case study in arid–semiarid environments, Northwest of China

  • Environmental Toxicology and Biogeochemistry of Ecosystems
  • Published:
Environmental Science and Pollution Research Aims and scope Submit manuscript

Abstract

Changes in potential evapotranspiration will affect the surface ecology and environment of the land. Accurate and quick estimation of potential evapotranspiration will help to analyze environmental change. In this study, in combination with the canonical correlation analysis (CCA) and k-nearest neighbor algorithm (k-NN), a new method for calculating potential evapotranspiration (CCA-k-NN) based on self-optimizing nearest neighbor algorithm was proposed, in which less meteorological data were used for estimation. By analyzing the basic principles of CCA and k-NN and according to the requirement of estimating ET0, the CCA-k-NN method was constructed, and its basic principles and key steps were described. In this method, CCA algorithm was used to find the most relevant meteorological data for potential evapotranspiration, and the dimensionality of meteorological data for subsequent estimation of ET0 was reduced. Then, k-NN algorithm was used to estimate ET0. The Northwest of China was chosen as the research area to evaluate the applicability of this method. The 148 data stations in the region were divided into training datasets, testing datasets, and validation datasets. ET0 was estimated on three datasets using the proposed method, and the estimation accuracy of the CCA-k-NN method was evaluated with FAO-56 Penman-Monteith as a reference. The results show that the CCA-k-NN method maintains a high correlation with FAO-56 Penman-Monteith (correlation coefficient is greater than 0.9) and has a good estimation accuracy. RMSE and MAE are both less than 1 mm day−1, and the overall performance of NSCE is greater than 0.5, all of which reach the level of “applicable” and above. At the same time, the CCA-k-NN method has low time complexity O(n). Comparison of the results of the CCA-k-NN method with those of other empirical models showed that the CCA-k-NN method is more accurate and can be employed successfully in estimating ET0.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11

Similar content being viewed by others

References

Download references

Acknowledgments

This study was supported by the university first-class discipline construction project of Ningxia, China (Grant No.NXYLXK2017A03); the Natural Science Foundation of Ningxia, China (Grant No. 2019AAC03049); the scientific research project of Ningxia Colleges and universities, China (Grant No. NGY2017026), and the China Scholarship Council (Grant No.201708645016).

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Kepeng Feng.

Additional information

Responsible editor: Marcus Schulz

Publisher’s note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Electronic supplementary material

ESM 1

(DOCX 15 kb)

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Feng, K., Tian, J. Estimating potential evapotranspiration based on self-optimizing nearest neighbor algorithms: a case study in arid–semiarid environments, Northwest of China. Environ Sci Pollut Res 27, 37176–37187 (2020). https://doi.org/10.1007/s11356-019-06597-7

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11356-019-06597-7

Keywords

Navigation