Potential evapotranspiration models evaluation, modelling, and projection under climate scenarios, Kesem sub-basin, Awas

  • PDF / 1,233,254 Bytes
  • 12 Pages / 595.276 x 790.866 pts Page_size
  • 8 Downloads / 184 Views

DOWNLOAD

REPORT


ORIGINAL ARTICLE

Potential evapotranspiration models evaluation, modelling, and projection under climate scenarios, Kesem sub‑basin, Awash River basin, Ethiopia Dame Yadeta1   · Asfaw Kebede2 · Negash Tessema3 Received: 29 January 2020 / Accepted: 24 May 2020 © Springer Nature Switzerland AG 2020

Abstract Evapotranspiration is a complex process in the hydrological cycle that influences the quantity of surface and groundwater. This study strives to evaluate potential evapotranspiration (PET) estimating models, modeling, and project potential evapotranspiration under climate scenarios. For models evaluation, the modified Hargreaves–Samani, Thornthwait, and Blaney–Criddle were evaluated against the FAO 56 Penman–Monteith method using the relative error (Re), normalized root-mean-squared error, and Pearson correlation (r). Multiple linear regression technique has been used to develop a PET estimation model using six climate parameters (minimum and maximum temperatures, relative humidity, wind speed, solar radiation, and sun hours). Outputs of 17 global climate models ensemble were used for RCP 4.5 and 8.5 emission scenarios to predict future PET. The correlation of climate parameters with PET reveals solar radiation, and Tmax had strong correlation (r) (0.73 and 0.8) at Shola Gebeya and (0.65 and 0.8) at Aleltu Agriculture, respectively, than other considered parameters. The models evaluation shows the modified Hargreaves–Samani equation performed better than others at both Shola Gebeya and Aleltu Agriculture stations. The result of multiple linear regression model shows the input variables used in the modeling were sufficient, implying that this model can be successfully used in estimating PET. Overall, the estimated PET using the multiple linear regression models under RCP 4.5 and 8.5 emission scenarios shows an increasing trend—this is pillar information for the water users in the study catchment. Keywords  Potential evapotranspiration · Modeling · Climate change · Multiple linear regressions · Kesem sub-basin

Introduction

Electronic supplementary material  The online version of this article (https​://doi.org/10.1007/s4080​8-020-00831​-9) contains supplementary material, which is available to authorized users. * Dame Yadeta [email protected] 1



Natural Resource Management Department, College of Dry Land Agriculture, Samara University, P.O. Box 132, Samara, Ethiopia

2



Hydraulic and Water Resources Engineering Department, Haramaya Institute of Technology, Haramaya University, P.O. Box 138, Dire Dawa, Ethiopia

3

Water Resource and Irrigation Engineering Department, Haramaya Institute of Technology, Haramaya University, P.O. Box 138, Dire Dawa, Ethiopia



Evapotranspiration is a complex process in the hydrological cycle that influences the quantity of surface and groundwater. Evapotranspiration in general is a term used to describe the sum of evaporation and plant transpiration from the Earth’s land surface to atmosphere. It is the second most important component in the hydrological cycle after rainfa