Evaluation of Gridded Precipitation Datasets over Arid Regions of Pakistan

Kamal Ahmed,Shamsuddin Shahid,Xiaojun Wang,Khan Najeebullah,Nadeem Nawaz

doi:10.3390/w11020210

Abstract

The rough topography, harsh climate, and sparse monitoring stations have limited hydro-climatological studies in arid regions of Pakistan. Gauge-based gridded precipitation datasets provide an opportunity to assess the climate where stations are sparsely located. Though, the reliability of these datasets heavily depends on their ability to replicate the observed temporal variability and distribution patterns. Conventional correlation or error analyses are often not enough to justify the variability and distribution of precipitation. In the present study, mean bias error, mean absolute error, modified index of agreement, and Anderson–Darling test have been used to evaluate the performance of four widely used gauge-based gridded precipitation data products, namely, Global Precipitation Climatology Centre (GPCC), Climatic Research Unit (CRU); Asian Precipitation Highly Resolved Observational Data Integration towards Evaluation (APHRODITE), Center for Climatic Research—University of Delaware (UDel) at stations located in semi-arid, arid, and hyper-arid regions in the Balochistan province of Pakistan. The result revealed that the performance of different products varies with climate. However, GPCC precipitation data was found to perform much better in all climatic regions in terms of most of the statistical assessments conducted. As the temporal variability and distribution of precipitation are very important in many hydrological and climatic applications, it can be expected that the methods used in this study can be useful for the better assessment of gauge-based data for various applications.

Highlights

Precipitation is the key element of the global water cycle and influences the socio-economic development of any region [1,2]
The residual plot of University of Delaware (UDel) showed that errors abruptly increased the results show that Global Precipitation Climatology Centre (GPCC) precipitation has captured the observed precipitation more accurately after 1981
The performances of four gauge-based gridded precipitation products, namely, GPCC, Climatic Research Unit (CRU), APHRODITE, and UDel, which are widely used as an alternative to observed precipitation, were evaluated in this paper

Summary

Introduction

Precipitation is the key element of the global water cycle and influences the socio-economic development of any region [1,2]. Variations and changes in climate have drawn the attention of scientific society [3,4]. Precipitation data are important for studying the changes in the regional and global climate [5,6]. The major problem often encountered in conducting such studies is the unavailability of climatic data over a longer period. Notwithstanding available data, irregular distribution and scarceness of stations, mainly over the uninhabited regions, makes the data unsuitable for the hydrological applications [7]. It is observed that available data quality is mostly not suitable for hydro-climatological assessments

Methods

Results

Conclusion