Abstract
In regions of sparse gauge networks, satellite rainfall products are mostly used as surrogate measurements for various rainfall impact studies. Their potential to complement rain gauge measurements is influenced by the uncertainties associated with them. This study evaluates the performance of satellites and merged rainfall products over Ghana in order to provide information on the consistency and reliability of such products. Satellite products were validated with gridded rain gauge data from the Ghana Meteorological Agency (GMet) on various time scales. It was observed that the performance of the products in the country are mostly scale and location dependent. In addition, most of the products showed relatively good skills on the seasonal scale (r > 0.90) rather than the annual, and, after removal of seasonality from the datasets, except ARC2 that had larger biases in most cases. Again, all products captured the onsets, cessations, and spells countrywide and in the four agro-ecological zones. However, CHIRPS particularly revealed a better skill on both seasonal and annual scales countrywide. The products were not affected by the number of gauge stations within a grid cell in the Forest and Transition zones. This study, therefore, recommends all products except ARC2 for climate impact studies over the region.
Highlights
IntroductionRainfall plays an essential role in the effective management of key socio-economic activities including, rain-fed agriculture, hydro-electrical power generation, and water resources [1,2,3]
Rainfall plays an essential role in the effective management of key socio-economic activities including, rain-fed agriculture, hydro-electrical power generation, and water resources [1,2,3].This applies to Ghana and the rest of the West African countries in general like few other regions in the world, where rain-fed agriculture is predominant [4,5]
CHIRPS was observed to be the best with r = 0.74 and a minimal Root-Mean-Square Error (RMSE) value of 0.04. This was followed by GPCC and Tropical Rainfall Measuring Mission (TRMM) with RMSE values of 0.08 and 0.09, respectively
Summary
Rainfall plays an essential role in the effective management of key socio-economic activities including, rain-fed agriculture, hydro-electrical power generation, and water resources [1,2,3] This applies to Ghana and the rest of the West African countries in general like few other regions in the world, where rain-fed agriculture is predominant [4,5]. The latter was strongly impacted by both the dearth and excess of rainfall during the severe Sahelian drought in the 1970s–1980s and several flood seasons in the last decade, respectively, which have raised awareness about the significant vulnerability of the West African region. The latter is further complicated by the poor coverage of rainfall data in the Global Telecommunication System (GTS) [6], which have generally caused limited confidence in recent rainfall trends for West Africa [11]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
