In searching for current topics related to LUCC and its consequences in hydrological regime changes, there seems to be a general trend in research papers arguing about "up-scaling¹". For example, In their invited commentary, Tetzlaff et al. (2007) argued that the progress toward a more holistic understanding of catchment functioning "has been hampered by a focus on reductionist approaches at small spatial² and temporal scales." (p1385). The authors then use a rather unusual but intriguing term to set the cornerstone of the needed research direction: CONNECTIVITY. Connectivity in the paper appears to carry the meaning of the flow between components, where components can be SNAP entities such as fishes, water, and catchment³. The authors also argued about the consideration of spatial patterns (and thus forming heterogeneous patches) in the ecohydrology research and how concepts of fragmentation⁴ (see Giambelluca, 2002) should be included to improve the understanding of hydro and ecological consequences of LUCC.

In general, I think the paper focuses on a better understanding of the forcing, i.e., what causes a certain phenomenon to occur, by anchoring the research on the concept of connectivity, or the flow channels between components in the physical systems. The focus is to examine how such channel respond or change at a larger scale.

The authors mentioned that the patches are dynamic (p1386) and are linked to hydrological connectivity. This somehow looks like a semantic net, implemented on a graph over time.



Footnotes
¹Scale means spatial extent and/or temporal duration. Here up-scaling means the incorporation of larger spatial extent (e.g., larger catchment areas) or longer time series data.
²Tetzlaff considers small scale as areas less than 10 square meters (called reach scale).
³I focus only on scientific definition of catchment. The separation of concept, meaning, and token (citation?) is not considered here.
⁴This is referred to as texture in remote sensing image interpretation. The concept seems to suggest that existing research either misses the linkage between patches by just sampling some representative patches and not considering the connections between them, or simply just neglect the existence of these patches by lumping them into a larger area with homogeneous properties.

Reference
Giambelluca, T. W., 2002, Hydrology of altered tropical forest, Hydrological Processes, 16(8), 1665-1669

Tetzlaff, D., Soulsby, C., Bacon, P. J., Yongson, A. F., Gibbins, C., and Malcolm, I. A., 2007, Connectivity between landscapes and riverscapes - a unifying theme in integrating hydrology and ecology in catchment science? Hydrological Processes,21(10), 1385-1389