Impacts of Climate Change and Land-Use Change on Hydrological Extremes in the Jinsha River Basin

Abstract

Hydrological extremes are closely related to extreme hydrological events, which have been and continue to be one of the most important natural hazards causing great damage to lives and properties. As two of the main factors affecting the hydrological cycle, land-use change and climate change have attracted the attention of many researchers in recent years. However, there are few studies that comprehensively consider the impacts of land-use change and climate change on hydrological extremes, and few researchers have made a quantitative distinction between them. Regarding this problem, this study aims to quantitatively distinguish the effects of land-use change and climate change on hydrological extremes during the past half century using the method of scenarios simulation with the soil and water assessment tool (SWAT). Furthermore, the variations of hydrological extremes are forecast under future scenarios by incorporating the downscaled climate simulations from several representative general circulation models (GCMs). Results show that: (1) respectively rising and declining risks of floods and droughts are detected during 1960–2017. The land use changed little during 1980–2015, except for the water body and building land. (2) The SWAT model possesses better simulation effects on high flows compared with low flows. Besides, the downscaled GCM data can simulate the mean values of runoff well, and acceptable simulation effects are achieved for the extreme runoff indicators, with the exception of frequency and durations of floods and extreme low flows. (3) During the period 1970–2017, the land-use change exerts little impact on runoff extremes, while climate change is one of the main factors leading to changes in extreme hydrological situation. (4) In the context of global climate change, the indicators of 3-day max and 3-day min runoff will probably increase in the near future (2021–2050) compared with the historical period (1970–2005). This research helps us to better meet the challenge of probably increased flood risks by providing references to the decision making of prevention and mitigation measures, and thus possesses significant social and economic value.

Separate and Combined Impacts of Land Cover and Climate Changes on Hydrological Responses of Dhidhessa River Basin, Ethiopia

“…Several studies have reported that surface runoff is more sensitive to land cover change than to climate change [4,34,71]. In contrary, there are studies that have argued that surface runoff is more sensitive to climate change than to the land cover change [22,72]. Similarly, a study of small watershed located in the upper Blue Nile basin showed that AET is more sensitive to land cover change than to climate change [71].…”

Innovative Trend Analysis of Air Temperature and Precipitation in the Jinsha River Basin, China

“…Human-induced land cover change is reported to have an impact on the regional climate [48]; however, Yin et al [49] pointed out that for the whole JRB, the share of each primary land use category did not vary notably from 1975 to 2000. Additionally, from 1970 to 2017, land use change exerted little impact on runoff extremes, while climate change was one of the main factors that led to changes in extreme hydrological situations [50]. did not vary notably from 1975 to 2000.…”

“…did not vary notably from 1975 to 2000. Additionally, from 1970 to 2017, land use change exerted little impact on runoff extremes, while climate change was one of the main factors that led to changes in extreme hydrological situations [50]. Annual air temperature and precipitation in the JRB have a high spatial variability, where the southeastern JRB is warmer and wetter than the northwestern area (Figure 2a,c,e).…”

“…Based on a digital elevation model and the distribution of hydrological stations, the JRB was divided into four sub-basins ( Figure 1): the source region of the JRB (SRJRB), the upper part of the JRB (UPJRB), the Yalong sub-basin (YLRB), and the middle and lower parts of the JRB (MLJRB). The regional mean air temperature and precipitation were calculated using the Thiessen polygon method based on observations from 40 meteorological stations [38,50].…”

Performance Evaluation of a Two-Parameters Monthly Rainfall-Runoff Model in The Southern Basin of Thailand

“…Many research topics regarding the rainfall-runoff model have been studied, developed, and applied by hydrologists and irrigation engineers for many aspects. For example, Chen, et al [6], Kabiri, et al [7], Lin, et al [8] applied the rainfall-runoff model to assess runoff impacts due to climate and land-use change. Kwak,et al [ 9] also used the rainfall-runoff model to reconstruct the missing runoff time-series information.…”