Effects of land use and topographic characteristics on seasonality water quality at multi-spatial scales: a case study of Weihe River Basin

Abstract To explore the relationship between land use and basin water quality can effectively contribute to the protection of the latter at the landscape level. This research concentrates on the Weihe River Basin (WRB), a multi spatial scale correlation model was established in the WRB for both dry and wet seasons based on multiple linear regression analysis (MLR). A quantitative analysis of relationship between land use structure and basin water quality at the sub-basin, riparian zone, and river scales. The slopes were selected as the topographic characteristics to further, to explore the complex relationship between land use structure and topographic characteristics. By analyzing samples collected at 40 sites, it was shown that the correlation between water quality variables and different land use patterns was higher in the dry season than in the wet season, and that the land use at the riparian zone scale explained the overall water quality variations better than that at the sub-basin and river scales. Compared with other land uses, agricultural and urban lands had a better relationship with water quality, which was most affected by land use area and morphological indicators. In addition, the greater the area and aggregation of forest land and grassland, the better the water quality; while urban land presented larger areas with poorer water quality. The influence of steeper slopes on water quality was more remarkable than that of plains at the sub-basin scale, while the impact of flatter areas was greater at the riparian zone scale. The present study makes a number of recommendations related to the adoption of water quality protection and construction planning in the WRB.