Spatial pattern of surface water quality in China and its driving factors—implication for the environment sustainability

<p>Previous studies on water quality in China have been limited within a relatively constrained geographical area to interpret the relationships between water quality and its controlling factors. Such limited choice may give unreliable results, and a national study may help fill this gap. We first interpreted the dominant drivers controlling spatial patterns of surface water quality in the whole China at three scales (watershed, 1-km-buffer, and self-defined zone). The higher responsibility coefficients in spatial water quality models of urban and cropland than other lands imply that both urbanization and crop production have shown severe impact on surface water quality, accompanying with a dilution effect from rainfall at all spatial scales. Finally, a first exponential response of water quality measures to the scenarios of land use and land cover change had been originally demonstrated at the national level, suggesting higher sensitivity of clear water in some remote areas to potential pollutants, and a big challenge for improving the degraded water quality in some areas under intensive human activities. Our findings highlighted that it is urgent for decision-makers to make a scientific and reasonable macro-level policy for the sustainable development of water resources in China.