August 2017

Evaluation of empirical models for estimating reference-evapotranspiration (RET-ET) in humid semi-hot equatorial coastal climate

The performances of five empirical models, namely: Hargreaves-Samani, Makkink1 (1957), Makkink2 (1984), Priestley-Taylor and FAO 56-PM in estimating reference evapotranspiration (REF-ET) were separately compared with Epan data and FAO 56-PM, respectively. Based on statistical analysis, Hargreaves-Samani method compared best with daily and monthly Epan data, while Makkik2 (1984) ranked first with FAO 56-PM. In terms of...

Author(s): Itolima Ologhadien and Ify L. Nwaogazie

August 2017

Analysis of spatial and temporal drought variability in a tropical river basin using Palmer Drought Severity Index (PDSI)

Analysis of spatial and temporal drought variability in the upper Tana River basin using Palmer Drought Severity Index (PDSI) was conducted. The drought is critical for formulation of mitigation measures in the river basin. A monthly temporal and 90-m spatial resolution was applied. This was achieved within ArcGIS environment. Climatic data for 1970 to 2010 was used for computation of the PDSI while the missing data...

Author(s): Raphael M. Wambua, Benedict M. Mutua and James M. Raude