Role of reservoir construction in regional land use change in Pengxi River basin upstream of the Three Gorges Reservoir in China

Abstract

The impact of the Three Gorges Reservoir (TGR) construction on land use change has attracted worldwide concern. However, quantitative evidence is lacking for the drivers of land use change resulting from the TGR during and after construction. We used the Pengxi River basin, located upstream of the Three Gorges dam, to evaluate the effects of large-scale hydrological engineering on land use. Landsat remote sensing images from 1995, 2000, 2005 and 2010 covering the main construction period of the TGR were obtained. The largest changes were the conversion of land to water bodies and built-up areas, corresponding to reservoir impoundment and population resettlement during TGR construction. These changes were more intensive downstream of the TGR and closer to the river. Compared with 2000-2005, the expansion in water bodies during 2005-2010 moved from lower to higher elevations. The distribution of built-up land during the two periods was similar, mainly because the planned resettlement zones were fixed and spatially concentrated. Geographical and environmental factors, such as elevation, slope, location, soil type and precipitation, still controlled land use patterns. Land use pattern in 2020 under two scenarios was simulated using a multi-criteria evaluation cellular automata-Markov model. Scenario 2 was more realistic and helpful for management decisions. The scenarios highlighted the indirect influences of TGR construction on land use change after 2010. Indirect driving forces were mainly reflected through related policies or plans, especially from the perspective of water conservation in the newly built reservoir.

Characteristics of Landscape Change Patterns at Three Distinct Stages of the Construction and Operation of the Three Gorges Reservoir From 1986 to 2017

“…The formation of the TGRA is a direct consequence of the dam 55 . According to previous relevant studies, the TGRA can be divided into three significant time periods: the construction period, impoundment period and Post-Three Gorges era 56,57 . Considering the actual situation of the hinterland basin of the reservoir area and the difficulty of data acquisition, this study is divided into three phases: 1986~2000, 2000~2010 and 2010~2017 (Fig.…”

A Review of Earth Observation-Based Analyses for Major River Basins

“…On the other hand, ∼79% of these studies performed regional and subbasin scale land cover and land use change analyses. Here, dam induced land cover change was analyzed particularly often [81][82][83][84][85]. For example, Feng et al [85] investigated regional land cover change induced by the construction of the Belo Monte dam in the Amazon river basin.…”

From divide to nexus: Interconnected land use and water governance changes shaping risks related to water

“…floods, droughts and poor water quality), and vulnerability towards them, are driven by changes in land and water use, as well as by their interconnections. Unsustainable land use changes have been recognized to have considerable implications on water (Delpla et al 2009;Foley et al 2005;Rockström et al 2009;Steffen et al 2015), while changes on water use and governance have considerable effects not only on water but also on land use (Alemayehu et al 2009;Wang et al 2016).…”

“…Large-scale water management infrastructure and hydropower projects significantly alter hydrological systems (e.g. streamflow, runoff, storage and infiltration) (Gao et al 2013;Lu et al 2014;Muñoz-Salinas and Castillo 2015), and changes in management and governance of water resources have also implications for land use (Alemayehu et al 2009;Desta et al 2017;Wang et al 2016). In many cases, changes in land and water use are clearly intertwined, such as in the embankment and canalization of water for flood protection and to support land conversion to agriculture and built-up areas (Marçal et al 2017; Ritzema and Van Loon-Steensma 2017).…”