The socio-spatial response to environmentally mitigated channelization in Southeast Asia. A longitudinal landscape pattern analysis

Rural-to-urban transformation in Southeast Asia must be discussed as a vicious cycle of hydrologic alteration, environmental degradation, and destructive land use changes that collectively jeopardize millions of lives. Particularly, top-down flood control schemes have been linked to significant degradation of the socioeconomic and biophysical features of rural landscapes and increasingly faster agricultural decline and environmental degradation.

In recent years, growing awareness has focused on ecosystem fragility and the need for a water-sensitive approach in planning. Water management and stream renaturation are expanding and rapidly developing disciplines that have produced radical advancements in ecological, geomorphological, and hydrologic areas. Despite such progress, however, these disciplines have failed to offer major advancements in socially related fields. A paucity of scientific research exists on the association between hydrologic alteration and the transformation of the landscape—which is a socially constructed phenomenon. As a result, the socio-cultural response to the morphological transformations of water regimes in peri-urban and desakota areas remains under-investigated.

The current study questions whether a specific morphological transformation of water streams, namely channelization cum environmental mitigation, can catalyze socio-cultural reactions and thus shape peculiar land use patterns. To examine that impact, we conducted a study on the Sheung Yue River in the New Territories of Hong Kong. Longitudinal data on the morphological change of the landscape at the catchment level from 1994 to 2022 were interpreted from aerial photographs and high-resolution satellite imagery, controlling for external factors. Alongside that data, 20 semi-structured interviews with local farmers provided in-depth knowledge of societal responses to the landscape mutation. Eleven interviews with knowledgeable informants also enhanced the understanding of river management and agricultural conservation. The overall findings revealed that integrating environmental mitigation strategies in channelization can moderate the negative impacts of the engineering-driven fluvial morphological transformation. Based on these findings, the study stresses the significance of socio-environmental responsive river management and integrated urban planning strategies for policymaking in Southeast Asia.