Projected temperature and precipitation changes using the LARS‐WG statistical downscaling model in the Shire River Basin, Malawi

Abstract

This study analyzes local‐scale temperature and precipitation projections in the Shire River Basin (SRB) in Malawi using 10 global circulation models (GCMs) available in the coupled model intercomparison project phase 5 (CMIP5), under two representative concentration pathways (RCP 4.5 and RCP 8.5). For nine stations in the study area, large‐scale maximum temperature (Tmax), minimum temperature (Tmin) and precipitation data from the selected GCMs were downscaled by the sixth version of the Long Ashton Research Station Weather Generator (LARS‐WG6). The mean seasonal and annual change projections for Tmax, Tmin and precipitation during two future periods, that is, the middle future (2041–2070) and late future (2071–2100) periods were analyzed. Modelling results demonstrated that the LARS‐WG model is capable of simulating temperature more accurately than precipitation in the SRB. All 10 GCMs revealed that continually rising temperatures are anticipated in the study area; however, the projected magnitude of change varied across GCMs and between RCPs. Generally, the increase in average Tmax and Tmin was observed to be higher under RCP 8.5 compared with RCP 4.5 due to unmitigated greenhouse gas emissions (GHGs). Future precipitation change results showed more complexity and uncertainty than for temperature; not all GCMs agree on whether there will be positive or negative changes in precipitation and no systematic variations under RCP4.5 and RCP8.5 were observed during the two future time period, illustrating that both GCMs and RCPs are important sources of the relatively large uncertainties in future precipitation projections in the SRB. Thus, this study indicated that uncertainties constrained by both GCMs and RCPs are crucial and need to always be considered when executing climate impact studies and adaptation, particularly at river basin level.

Future Climate Projections using the LARS-WG6 downscaling model over Upper Indus Basin, Pakistan

“…The ndings of this study are in agreement with the IPCC 5th assessment report and con rm that RCP8.5 projections are higher than RCP4.5, which may be attributed to the former's limited mitigation and adaptation policies. The temperature trends expected by different RCMs are also consistent with previous research ndings by(Stott & Kettleborough, 2002), (Fenta Mekonnen & Disse, 2018), and(Kavwenje et al, 2022) where they all noticed that increment in temperature was more sensitive to emission scenario in 2080s as compared to 2050s.Akhtar et.al (2008) have used PRECIS Regional Climate Model and predicted that temperature shows increasing trends towards the end of this century Ismail et al (2020). have used an ensemble of four GCMs to predict future climate over UIB.…”

The impacts of climate changes on watershed streamflow and total dissolved nitrogen in Danjiang Watershed, China

“…The standard deviation of the synthetic daily precipitation in September is underestimated because the precipitation pattern in this month is elusive and unpredictable. However, it is acceptable within the same level as other LARS-WG model applications (Bayatvarkeshi et al 2020;Kavwenje et al 2021). The mean values of the monthly precipitation and minimum and maximum temperatures can be estimated by the LARS-WG model and qualified for further scenario analysis to generate synthetic weather data.…”

“…Subsequently, based on the calibrated model parameters, 67 years of synthetic daily weather data were generated and compared with the observed data to validate the parameters. Consistent with existing research (Bayatvarkeshi et al 2020;Kavwenje et al 2021), three statistical tests for eight indicators were used to test whether the observed and synthetic values were derived from the same population (Table 2).…”

Modeling Seasonal Malaria Transmission: A Methodology Connecting Regional Temperatures to Mosquito and Parasite Developmental Traits

“…While there is variation in the magnitude of the increase between seasons, they projected that temperatures would increase across all seasons. Although the majority of climate models considered by Kavwenje et al (2022) consistently projected temperature increases in this region, one model did suggest the possibility of a temperature decrease. With the idea that climate change can lead to more extreme weather, we considered the impact of both increases and decreases in monthly temperature in this study.…”

“…Temperature data for Malawi from 1961 to 2005 indicates an annual rate of temperature increase of 0.3°C per year (Warnatzsch and Reay, 2019). Kavwenje et al (2022) projected an increase in the mean seasonal maximum temperature in Malawi of 1.63 to 2.48 degrees celsius in the 2050s, and between 2.32 and 4.68 degrees celsius in the 2080s. Likewise, the mean seasonal minimum temperature is projected to increase by 1.74-2.53 in the 2050s and 2.41-4.60 in the 2080s.…”