Landscape composition or configuration: which contributes more to catchment hydrological flows and variations?

Abstract

Landscape composition and configuration determine the generation and exchange of water flows among different landscape patches and may affect catchment hydrological flows and variations. However, the poor understanding on the effects of landscape patterns on hydrological processes limits the implementation of landscape planning and management practices for regulating catchment water resources at the practical level. The aims are to determine the relationship between the landscape pattern and hydrological flows and variations, and to compare the contributions of landscape composition and configuration to the hydrological flows and variations. Landscape patterns were quantified and hydrological flows and variations were observed in a Chinese subtropical catchment with ten sub-catchments during 2011–2017. The relationship among landscape composition, configuration, and hydrological flows and variations was analysed by Pearson correlation, and their relative contributions were determined by the variance partitioning analysis. Landscape composition and configuration were significantly correlated with catchment stream, direct, and base flows and variations, of which high fragmentation degree increased stream and base flows, great shape complexity aggravated the volatility of stream flow, high patch aggregation adversely impacted stream, direct, and base flows, and high patch evenness and lower richness increased stream and base flows. Landscape composition and configuration indices could be employed to effectively predict hydrological flows and variations. Landscape configuration had greater contribution than landscape composition to subtropical catchment hydrological flows and variations, and optimizing landscape configuration could improve our regulatory capacity and ability of catchment water resources management and utilization in the subtropical catchments at the practical level.