Potential Impacts of Climate Change on Water Resources in the Kunhar River Basin, Pakistan

Abstract

Abstract:Pakistan is one of the most highly water-stressed countries in the world and its water resources are greatly vulnerable to changing climatic conditions. The present study investigates the possible impacts of climate change on the water resources of the Kunhar River basin, Pakistan, under A2 and B2 scenarios of HadCM3, a global climate model. After successful development of the hydrological modeling system (HEC-HMS) for the basin, streamflow was simulated for three future periods (2011-2040, 2041-2070, and 2071-2099) and compared with the baseline period to explore the changes in different flow indicators such as mean flow, low flow, median flow, high flow, flow duration curves, temporal shift in peaks, and temporal shifts in center-of-volume dates. From the results obtained, an overall increase in mean annual flow was projected in the basin under both A2 and B2 scenarios. However, while summer and autumn showed a noticeable increase in streamflow, spring and winter showed decreased streamflow. High and median flows were predicted to increase, but low flow was projected to decrease in the future under both scenarios. Flow duration curves showed that the probability of occurrence of flow is likely to be more in the future. It was also noted that peaks were predicted to shift from June to July in the future, and the center-of-volume date-the date at which half of the annual flow passes-will be delayed by about 9-17 days in the basin, under both A2 and B2 scenarios. On the whole, the Kunhar basin will face more floods and droughts in the future due to the projected increase in high flow and decrease in low flow and greater temporal and magnitudinal variations in peak flows. These results highlight how important it is to take cognizance of the impact of climate change on water resources in the basin and to formulate suitable policies for the proper utilization and management of these resources.

Development of Threshold Levels and a Climate-Sensitivity Model of the Hydrological Regime of the High-Altitude Catchment of the Western Himalayas, Pakistan

“…There is a discontinuous layer of water on the surface of the Earth, known as the hydrosphere. Concentrations of greenhouse gases in the atmosphere are increasing, causing global warming and affecting precipitation [1]. These principle factors, i.e., precipitation and temperature, affect the hydrosphere due to their influence on snow [2] and glacial melt [3], which in turn affect runoff to major rivers [4][5][6], the levels of which have changed significantly [7][8][9][10].…”

“…As mentioned previously, due to the diversity of regions, it is useful to establish threshold levels of runoff sensitivity to the climate in a specific basin, so that water resources can be better planned and managed. Projected future temperature and precipitation trends were determined in the western Himalayas [1]. Similarly, different climate models have been used to predict the impact of future climate change on this region, without taking into account historical meteorological and hydrological time-series data [42,43].…”

Review on Water Resources Management and Key Threats in Rwanda, East Africa

“…The changing climate in Rwanda extant very serious national challenges and risks transversely various sectors such as agriculture and water resources.The report of the Intergovernmental Panel on Climate Change (IPCC) indicates that the climate is changing; the global average temperature is rising with shifting rainfall patterns, whereas the glaciers, arctic sea ice and Greenland ice sheet are melting, primarily due to greenhouse gases emitted in the atmosphere (Mahmood et al, 2016;Myhre et al, 2013). It is predicted that warm sea temperature and less precipitation may increase drought and desertification in the subtropical and equatorial Eastern Africa and consequently, these alterations will seriously impact on the quantity and quality of water, economy, food security and social welfare of poor countries mainly the Sub-Saharan countries including Rwanda.…”

Water Resource Variability and Climate Change

“…Mahmood et al [27] investigate the potential impacts of climate change on the water resources of the Kunhar River basin, Pakistan under A2 and B2 climate scenarios. Using the HEC-HMS (Hydrologic Engineering Center's Hydraulic Modeling System) hydrological model, the authors simulate streamflow for the periods: 2011-2040, 2041-2070, and 2071-2099, and compare them with the baseline period to explore changes in different streamflow variables.…”