Evaluation of water resources renewability in yellow river basin based on principal component analysis

The observed annual river discharge of Yellow River has declined significantly in the past 30 years. The drying-up events impacted by global change has been recognized as a very important issue in China. It is important to study on water resources renewability to improve the current situation of water resources in Yellow River Basin. In view of the disadvantages of current evaluation methods, this paper applies principal component analysis (PCA) to evaluate the water resources renewability. Principal component analysis is concerned with explaining the variance-covariance structure of a set of variables through a few linear combinations of these variables. It can transform a number of original correlation variables into a few uncorrelated principal components to reduce the dimensionality without much loss of information. In this paper, 15 major cities in the Yellow River Basin are selected to evaluate the water resources renewability. The results indicated that the water resources of Yellow River Basin have week renewability. Meanwhile, the differences of water resources renewability among these cities were given out. Baoji, Xinxiang, Dongying, Zhengzhou, Taiyuan, Hohhot, Baotou, Jinan were in the moderate level, and Luoyang, Xining, Xian, Xianyang, Yinchuan, Lanzhou, Kaifeng were in the week level.