**2. Study Area**

Pakistan is geographically located in southwest Asia with an area of 8 <sup>×</sup> 106 km2 between latitude and longitude range of 24–37◦ N and 60–75◦ E (Figure 1). The country has diverse topography that ranges from Karakoram and Himalayan mountains in the north and northwest to the agriculture plains in the center and south of the Indus basin along the southern cost of the Arabian sea [32]. Pakistan is an agrarian country and Punjab is the second largest Province with geographical coordinates of 31.17◦ N and 72.70◦ E. The Province has the largest population and producing more than 50% of the country's agricultural commodities [33]. The regional mean temperature varies from 23 to 26 ◦C, with a Tmin of 16–19 ◦C and a Tmax of 29–33 ◦C. The northern part of the Province receiving more precipitation than southern part with overall annual mean precipitation ranges from < 300 mm in the southern part to > 800 mm in the northern part [34]. The two major seasons that dominates the overall hydrology of the region, i.e., the summer monsoon (June–September) and winter monsoon seasons (December–April) [35]. The maximum precipitation occurs during the summer monsoon due to the monsoon system that originates from Bay of Bengal and enters in the country from east and northeast [35]. The winter precipitation instigates from the Mediterranean Sea due to western disturbances and enters in the country from southwest and northeast direction [35]. There is great variation and extreme events during summer and winter monsoon precipitation seasons that make this region a highly susceptible to climate change [36]. Due to highly vulnerable in precipitation changes, the spatial and temporal evaluation of the GPPs is highly important for further application of these products, including hydro-meteorological studies over the study region.

**Figure 1.** Study area and meteorological stations.
