Watershed management

According to scientists and hydrologists, water-related climate change impacts in Pakistan are melting glaciers, frequent floods, frequent droughts and changes in precipitation patterns.

Hydrologists say glaciers will be exhausted in the next 60-75 years since they have been melting at high rates due to continuous rise in temperatures. Pakistan will face an acute shortage of water in the future as 70 percent of the flow of River Indus depends on glaciers and melting snow.

The rise in temperature is also reducing snowfall annually. If we consider the fact that 50 percent of glaciers have melted, then after 60 to 75 years, melting snow will be available in rivers. In other words, at least 35-40 percent river flows will be reduced. India is constructing dams on rivers Chenab and Jhelum which will further reduce river flows in future. As a result, Pakistan will be facing an acute shortage of water for irrigation.

Pakistan has experienced frequent floods during the last few decades. Pakistan also faces frequent droughts in the country, particularly in its southern region. The droughts devastated lives and livelihoods in semi-arid regions of the country – eliminating $247 million worth of livestock in the first five months of the year 2000 alone. The fiscal impact of the droughts was estimated to be as high as Rs25 billion, given the lower nominal GDP growth, resulting in revenue losses and higher federal assistance to disaster-hit areas.

Seasonal droughts are occurring in the southern and western parts of the country, particularly in the Thar Parker desert for the last one decade.

Precipitation patterns have also changed in the country. Monsoon rains are extending towards the western and northern parts of the country. Gilgit-Baltistan, Malakand, Fata and north-eastern Balochistan did not fall in the monsoon zone but have been receiving monsoon showers for the last few years. Peshawar never experienced floods from the western watershed in Khyber Agency but for the last few years, flash floods have been occurring there every year during monsoon months.

Similarly, Balochistan, Fata and Gilgit-Baltistan experienced terrible floods during 2010 and 2015. The Chitral district was also hit by repeated flash floods during the monsoon seasons of 2015 and 2016. The associated landslides further added to the misery of inhabitants – blocking roads and destroying other infrastructure.

In order to tackle all four water-related climate change impacts, integrated watershed management should be implemented. In the past, these projects were employed in Mangla and Tarbela watershed areas to reduce siltation rate of multi-purpose dams and prolong their life.

Integrated watershed management practices include conservation measures – soil and water conservation and livelihood improvement. The former includes large-scale reforestation, surface erosion control on all land uses, gully and channel erosion control and landslide stabilisation measures. The livelihood improvement measures include increasing crop production, livestock production and off-farm livelihood improvement measures.

The integrated watershed management can solve the problem of flash floods by reducing the intensity of floods, thereby reducing damages. The most important role of forests in addition to conserving soil and slope stability is increasing the infiltration capacity of soil by which surface runoff is reduced and most of the rainfall absorbed. This is slowly released in the shape of interflow, springs and base flow into streams and rivers during dry periods.

Integrated watershed management can ensure sustainability of water resources – surface as well as groundwater. Similarly, vegetation also plays an important role in enhancing groundwater recharge for irrigation and domestic use.

Integrated watershed management can also mitigate the issue of drought in dry zone areas. Rainwater harvesting technology can be used for water resource development in order to provide water to livestock for domestic use as well as to establish fodder reserves. These reserves can be used to supply fodder for livestock during drought years only which will also discourage locals from migrating.

During droughts, government agencies and NGOs supply food and water to meet the shortage, but the amount is not enough. This triggers migration in search of better livelihood opportunities. Rainwater harvesting can be a solution for storing excess water.

Pakistan faces the most serious threat of climate change in the shape of glacial melt and subsequent water shortage. With forests playing an important role in conserving rainwater, the government should explore this alternative by constructing additional artificial reservoirs for storing floodwater during the monsoon season and using it for dry periods for irrigation and domestic use.

For sustainability purposes, artificial reservoirs along with large-scale integrated watershed management programme should be launched not only in the catchment areas of rivers Indus and Jhelum but also in their western tributaries originating from Hindu Kush and Suleman ranges since monsoon rains are shifting towards the northern and western parts of the country.

It is the need of the hour that our policymakers start promoting an integrated watershed management programme in all watershed areas of the country to mitigate the catastrophic impacts of climate change.

 

The writer is a former director of the
Pakistan Forest Institute (PFI).