This review seeks to examine connections between hydrology and biogeochemistry at the landscape scale. A review of research on landscape structure and organization provides a context for what follows, and seeks to integrate work at relevant scales in ecology and geomorphology; the degree of functional ‘connectedness’ between different landscape elements provides the key theme. Following a review of hillslope hydrology, links between hillslope runoff pathways and nutrient dynamics are then considered. We focus in particular on riparian zones, where nutrient dynamics has relevance for water-quality management in catchments. In conclusion, we argue that future studies need to focus on the critical near-stream zone, given its importance in coupling hillslope and channel systems.

Field hydrology is on the decline. Meanwhile, the need for new field‐derived insight into the age, origin and pathway of water in the headwaters, where most runoff is generated, is more needed than ever.Water Resources Research(WRR) has included some of the most influential papers in field‐based runoff process understanding, particularly in the formative years when the knowledge base was developing rapidly. Here we take advantage of this 50th anniversary of the journal to highlight a few of these important field‐based papers and show how field scientists have posed strong and sometimes outrageous hypotheses—approaches so needed in an era of largely model‐only research. We chronicle the decline in field work and note that it is not only the quantity of field work that is diminishing but its character is changing too: from discovery science to data collection for model parameterization. While the latter is a necessary activity, the loss of the former is a major concern if we are to advance the science of watershed hydrology. We outline a vision for field research to seek new fundamental understanding, new mechanistic explanations of how watershed systems work, particularly outside the regions of traditional focus.

Reed, M. S., K. Hubacek, A. Bonn, T. P. Burt, J. Holden, L. C. Stringer, N. Beharry-Borg, S. Buckmaster, D. Chapman, P. J. Chapman, G. D. Clay, S. J. Cornell, A. J. Dougill, A. C. Evely, E. D. G. Fraser, N. Jin, B. J. Irvine, M. J. Kirkby, W. E. Kunin, C. Prell, C. H. Quinn, B. Slee, S. Stagl, M. Termansen, S. Thorp, and F. Worrall. 2013. Anticipating and managing future trade-offs and complementarities between ecosystem services. Ecology and Society 18(1): 5. https://doi.org/10.5751/ES-04924-180105

Daily rainfall totals are analyzed for the main agro-climatic zones of Sri Lanka for the period 1976–2006. The emphasis is on daily rainfall rather than on longer-period totals, in particular the number of daily falls exceeding given threshold totals. For one station (Mapalana), where a complete daily series is available from 1950, a longer-term perspective on changes over half a century is provided. The focus here is particularly on rainfall in March and April, given the sensitivity of agricultural decisions to early southwest monsoon rainfall at the beginning of the Yala cultivation season but other seasons are also considered, in particular the northeast monsoon. Rainfall across Sri Lanka over three decades is investigated in relation to the main atmospheric drivers known to affect climate in the region: sea surface temperatures in the Pacific and Indian Oceans, of which the former are shown to be more important. The strong influence of El Niño and La Niña phases on various aspects of the daily rainfall distribution in Sri Lanka is confirmed: positive correlations with Pacific sea-surface temperatures during the north east monsoon and negative correlations at other times. It is emphasized in the discussion that Sri Lanka must be placed in its regional context and it is important to draw on regional-scale research across the Indian subcontinent and the Bay of Bengal.