Projected Rainfall Variability Based on PRECIS Regional Model

The present study indicates the potential projected variation of decadal mean rainfall over Kohistan region of Sindh Province, Pakistan. Precipitation variability is a crucial climatic factor that affects human health and their settlements. In this study, the precipitation variability associated with climate change in Kohistan region, Sindh, Pakistan is simulated using the PRECIS regional climate modeling system. The study analyses the precipitation variability in the future for two spells (2021-2050 and 2071-2099) with respect to the past (1961-1990) climate under the baseline ECHAM5 dataset for A1B Scenario at a resolution of 25x25 km. Based on this analyses, the precipitation scarcity is projected for 2021-2050 and 2071-2099 decades. The projected results showed a serious precipitation variation and shortfall of 12.60, 53.98, and 48.19% during 2031-2040,2041-2050 and 2081-2090 decades respectively as compared to baseline (1961-1990). The analyzed situation would be harmful to the water resources and agricultural production in the region during the shortfall, which imposes the adverse effect on the recharge of groundwater and quality. That might cause of long drought spell in the region. While during the 2021-2030 decade shown slight influence on the potential of hill torrents and groundwater recharge. However, the results reveal for the period of 2071-2080 and 2091-2099, the extreme floods with 60.50 and 70.50% are projected as compared to baseline 1961-1990. The increasing trend of precipitation indicates additional recharge of fresh groundwater and quality, with increasing level of aquifers, subsequently more agricultural production would be expected with alternate employment opportunities in the water sector. The projected results, indicating the decadal scenarios of the drought and wet spells in the region by the precipitation variation, which may impact on the hill torrents, groundwater and agricultural production, and employment opportunities. These quantitative projections should enable policymakers and stakeholders to plan for future measures.


INTRODUCTION
Climate change effects have been observed in Pakistan as significant variations in rainfall patterns and stream flows, increase in extreme events (floods/droughts), fluctuations in temperature, humidity, etc. According to the German watch Global Climate Risk Index, Pakistan has been listed among the ten countries most affected by climate change [2].The effect of environmental change influences distinctive parts of the country, including the rustic, and along the coastal and dry atmospheric parts, where the susceptibility of poor societies is expanding.
Access to foodstuff, water, and different assets is the primary task in those localities [3][4]. Women, in particular, bear more of the burden on the rural communities in The prediction of climatic conditions for a large number of years/decades with sufficient accuracy is a tremendous task [12]. Several attempts have been carried out to investigate the influence of climate change and predict future climate extremes over many regions in the world [13][14][15][16].
Ospina and Heeks [17]  It may take numerous years to establish a regional climate system after extreme incident depending on the harshness of droughts or floods [19]. Hence, water resources appraisal is essential in most critical regions where global warming may cause genuine devastations [7]. It helps policymakers and stakeholders make possible measures [9,20]. Accordingly, this study focused on the climate change impact in the Kohistan region of Sindh Province, Pakistan. The study objective is to investigate and predict variability in precipitation patterns in this region for the next 60 years (2021-2050 and 2071-2099) using PRECIS regional modeling system in order to identify options for future adaptation in this region. Several studies have used the PRECIS regional modeling system to assess climate change impacts and provide regional climate scenarios worldwide (e.g. [17,[21][22][23][24][25][26][27][28][29][30]. The reported accuracy level is empowering and supportive of future development in the various aspects of water demand. The PRECIS model combined with GIS/RS (Geographic Information System)/ (Remote Sensing) and shown accurate gap filling results of future projections precipitation inconsistencies and trend [31]. The use of a regional climate model e.g. [32][33] can provide a convenient tool for policymakers to manage this adversity and resolve climatic and geographical characteristics.

The Study Area
The study area covers 11,426 square kilometers, and it

PRECIS Modeling
In this study, the PRECIS Model ( Where Z(s i ) is the measured value at the i th location. λ i is an unknown weight for the measured value at the i th location. s 0 is the prediction location, and N is the number of measured values.

RESULTS AND DISCUSSION
The results revealed that the high range of rainfall ( (Fig. 3(a-b)). The precipitation results for the future scenario (2041-2050) depict that during this decade 46.02% precipitation of the referenced baseline is predicted (Fig. 5(a-b)). This  The post effects of the situation could result in a long period of drought, which may cause an increased migration rate, due to unemployment in the water sector and increasing poverty. Results of the last decade forecast based on the baseline precipitation period  show that during the 2091-2099 period, 170.42% precipitation occurrence is predicted ( Fig. 8(a-b)). These results expect extreme flash floods in the region. During the reported period (2091-2090), the reservoirs, ponds and small dams could potentially be filled with water, and the study area is expected to be covered with highly agriculture production. Groundwater quality is expected to improve due to fresh aquifers recharge. More land would cover under agriculture practice and employment opportunities in the water sector would be increased. Hence, no water deficit through hill torrents and groundwater potential is anticipated.   in the study area (Fig. 9).

CONCLUSION
The study showed that during the projected period

RECOMMENDATIONS
The

FUTURE WORK
The domain of current research work is the projection of rainfall variability through the PRECIS regional model.
Besides, that the projected data, will further be used to estimate rainfall run-off relationship on the annual and monthly basis in the next phase of research. For this purpose, a hydrological model would be used.