Runoff Responses to Climate and Land Use/Cover Changes under Future Scenarios

Abstract

Climate and land use/cover (LUC) are the two most significant factors that directly affect the runoff process. However, most research on runoff response has focused mainly on projected climate variation, while future LUC variability has been neglected. Therefore, the objective of this study is to examine the impacts of projected climate and LUC changes on runoff. -2020, 2021-2030, 2031-2040 and 2041-2050 period, abbreviated S3). These three scenarios are then input into the Soil and Water Assessment Tool (SWAT) model to assess runoff responses. Beijiang River Basin, located in southern China, is used in this case study. The results obtained from S1, S2 and S3 show that runoff change in this basin is mainly caused by climate change; warmer temperatures and greater precipitation increase runoff. LUC change has little influence on runoff at the whole-basin scale, but changes in runoff components are more notable in the urban area than in the natural region at the sub-watershed level. The impact of LUC change in urbanized region on runoff components differ obviously among the wet, normal and dry years, and surface runoff and groundwater are found to be more sensitive to urbanization. Runoff depth is predicted to increase in this basin under the impacts of both climate and LUC changes in the future. Climate change brings greater increase in water yield and surface runoff, whereas LUC change leads to changes in allocation between surface runoff and groundwater in the urban region.

The role of urban growth, climate change, and their interplay in altering runoff extremes

“…Our results, although refer to specifically developed scenarios, confirm the findings of other studies, which mostly showed a reduction in the groundwater and subsurface flow and an increase of the fast component due to the growth of impervious areas (e.g., Pan et al, ; Zhang et al, ). Sometimes the combination of the two changing factors may smooth the effect of land‐use change (Chawla & Mujumdar, ; Li, Zhang, & Xu, ; Pan et al, ; Pumo, Lo Conti, et al, ); in other cases, the changes in urbanization were demonstrated to have a greater effects (Cuo et al, ; Todd et al, ; Wang & Hejazi, ). Generally, the results depend on the simulated scenarios (either future synthetic scenarios or observed) and region under study (e.g., arid areas, uplands, lowlands).…”

“…Cumulative distribution functions (cdfs) of the hourly annual peak for all the scenarios: The cdf for the reference scenario (BAS-U 0 ) is reported in black, solid curves refer to U 0 map scenarios while dashed curves refer to U 1 map scenarios FIGURE 10 Percentage of variations of the GEV distribution parameters for each scenario with respect to the parameters relative to the reference scenario (BAS-U 0 ), for each of the four rainfall schemes 1, 2, 3, and 4 (along the four axes Our results, although refer to specifically developed scenarios, confirm the findings of other studies, which mostly showed a reduction in the groundwater and subsurface flow and an increase of the fast component due to the growth of impervious areas (e.g., Pan et al, 2017;Zhang et al, 2016). Sometimes the combination of the two changing factors may smooth the effect of land-use change (Chawla & Mujumdar, 2015;Li, Zhang, & Xu, 2014;Pan et al, 2017;Pumo, Lo Conti, et al, 2017); in other cases, the changes in urbanization were demonstrated to have a greater effects (Cuo et al, 2009;Todd et al, 2007;Wang & Hejazi, 2011 (Praskievicz & Chang, 2009). For this reason, the outcomes of this kind of study, including that here presented, should be contextualized in the specific territorial context of application.…”

“…In the last years, the ever-increasing availability of hydrological models (Chen et al, 2005;Karlsson et al, 2016;Mango, Melesse, McClain, Gann, & Setegn, 2011;Pumo, Lo Conti, Viola, & Noto, 2017;Quilbe et al, 2007;Todd, Goss, Tripathy, & Harbor, 2007;van Roosmalen, Sonnenborg, & Jensen, 2009;Zhang, Nan, Xu, & Li, 2016) and data from observations (Pumo, Arnone, Francipane, Caracciolo, & Noto, 2017) has led to study the combined effect of climate change and urban growth on the hydrological response of a catchment. Most of these studies have demonstrated that the hydrological impacts of land-use change can be compounded or offset by changes in regional climate (Chawla & Mujumdar, 2015;Cuo, Lettenmaier, Alberti, & Richey, 2009;Pan et al, 2017;Pumo, Lo Conti, et al, 2017;Todd et al, 2007). For example, Todd et al (2007) found out that, in the analysed area, the land-use changes had a greater influence on watershed hydrology than climate.…”

Variability of Temperature and Its Impact on Reference Evapotranspiration: The Test Case of the Apulia Region (Southern Italy)

“…In the last three decades, many studies have addressed the issue of climate evolution under anthropic pressure [1]. An increase of the annual mean global temperature and changes of other climate parameters have been observed in the last century [2][3][4][5]. In fact, many papers particularly concern global climate modelling and the recent warming due to human activity.…”

Relationship between Park Composition, Vegetation Characteristics and Cool Island Effect

“…Rapid urbanization enlarges the range of urban area and changes the feature of the ground surface [5]. Land Use/Land Cover (LULC) affect runoff process and impact the climatic condition in urban, especially for the development of UHI [6,7], leading to higher temperatures in the urban areas than the suburban areas. UHI effect, an acknowledged issue in large cities and different climatic regions, is becoming a common concern in smaller cities as well [8].…”