Land-use changes reinforce the impacts of climate change on annual runoff dynamics in a southeast China coastal watershed

Abstract

Abstract. Study on runoff dynamics across different physiographic regions is fundamentally important to formulate the sound strategies for water resource management especially in the coastal watershed where peoples heavily concentrated and relied on water resources. The L−R diagram, a conceptual model by which the land-changes evapotranspiration (ΔL) was estimated as the difference between actual and climate evapotranspiration to identify the specific impact of land-use changes on annual runoff changes (ΔR), was developed using the 53-year hydro-climatic data of Jiulong River Watershed, a typical medium-sized subtropical coastal watershed in China. This study found that land-use changes have reinforced the impact of climatic changes on runoff changes where nearly all points were scattered in II and IV quadrant. Deforestation and expansion of built up area has diminished the water retention capacity in a catchment as well as evapotranspiration thus produce extra runoff accounting for 12–183 % of total runoff increase. In contrast, reforestation makes the significant contribution to decreasing annual runoff for about 21–82 % of total runoff loss. This study revealed the river runoff has become more vulnerable to intensive anthropogenic disturbances under the context of climate changes in a coastal watershed.

Simulation of Freshwater Ecosystem Service Flows under Land-Use Change: A Case Study of Lianshui River Basin, China

“…We fixed the meteorological data in 2000, stripped off the impact of land-use change, and found that the land-use change in the river basin expanded the impervious layer area and increased the water supply by 0.01 billion m 3 from 2000-2018. This conclusion is consistent with the conclusions of [16,45] and others. The increase in construction area has led to an increase in water demand.…”

Changes in supply and demand mediate the effects of land-use change on freshwater ecosystem services flows

“…However, most studies have confounded the effects of climate change with land-use. Instead, we isolated the effects of land-use change by fixing meteorological data to 1991 and found that land-use change diminished water retention capacity and contributed extra water supply, a result consistent with that of Ervinia et al (2015). For example, the greatest effects were experienced in sub-catchment 9 which showed the largest increment of water supply under urbanization (Fig.…”

Assessing the Influence of Climate Change and Anthropogenic actions on Water Resources in the Wami River Catchment, Tanzania

“…Whereby, ufx is the forward, and the backward sequence ubx is calculated using the same equation but with reversed data (Ervinia et al 2017).…”