[This blog post is the English version of the Nepali article published in Kantipur Daily on May 27, 2015].
What we learn in Geography 101 about the processes of the formation of mountains, valleys, waterfalls, and streams and rivers do not make sense in a real way until one sees the glimpse of that massive power of nature changing landscape around us. And then those lessons make very good sense when one has the opportunity to witness the landscape, taken for granted to be standing for ever; crumbling, falling and collapsing when big earthquakes shake them. Not many people have the opportunity to witness such event that occurs every 80, 90 years. We in central Nepal had this opportunity to witness one of those tens of thousands of rare events that have shaped the Himalayas over a period of tens of millions of years – the big earthquake of April 25, 2015.
The big jolt of 25th April moved Kathmandu Valley to the south by 3 meters and raised it by about a meter. Some of the mountain areas in the north have subsided by perhaps a meter too. We may not know what these shifts have done to the natural resources and the subsequent impacts on the lives of millions of people whose livelihoods depend on them, but there are clear indications that the earthquake and the following aftershocks have changed the land and water sources in the earthquake affected area for ever. This may eventually be a big challenge for our rural economy and livelihoods.
It is difficult to say at this stage to what extent the big jolt and the hundreds of aftershocks have affected the poorly understood interrelationships among land, water and vegetation. Because these are the same aspects upon which economic aspects of our livelihoods depend. However, we can judge, with some level of confidence, the damage caused by the quake to the very foundation of the livelihoods – land and water. Needless to say that the land is the foundation of water sources, and the changes in the shape and the structure of land, which the quake has already inflicted, affects both land and water sources. First, let’s see the impacts on the land in EQ affected areas.
Just by looking at the dry landslides seen across the mountains and the cracks on ground , any one can say that there will be widespread erosion and landslides this monsoon. This speculation is reinforced by reconnaissance of the EQ affected area conducted by a team of experts which noticed more than 3000 dry landslides mostly in the northern part of the country. The landslides had already caused damages to the landscape with threats of blocking the road and the river. Numerous and widespread cracks on the ground were made evident by another study conducted using satellite imagery immediately after the quake. Those studies have predicted that large numbers of landslides are likely to occur with monsoon rain.
Damage to land
It is clear that we will have to deal with three types of problems regarding landslides and erosions.
- Firstly, the dry landslides in the steep rocky faces of the northern mountains. Massive landslide in Rasuwa have already wiped out the village of Lantang. Several of them have damaged a large part of the mountain slope between Barabise and Tatopani near Chinese border in Sindhupalchok blocking the highway between these points. In some places, people fear that the entire mountain may collapse. Tatopani area was deserted for sometime after the quake as people fled the area. The list of landslide damaged places could be very long. There may be many other damaged areas that we have no information about. These landslides capable of blocking the road and the rivers are still active. A landslide that occurred in Ramche of Myagdi on the 30th day of the big earthquake blocked Kali Gandaki River for 16 hours causing threats to the nearby settlements. These dry landslides may become more active once the monsoon begins.
- Secondly, landslides that may start with the onset of monsoon. There are numerous cracks on the ground in most of the settlements and farms. In some places the cracks are very dense which have shattered the land. There may be similar cracks in the forest areas as well. These cracks are going to divert monsoon water to places that may be weak and cause landslides and gully erosion. They may also wash villages. The entire blocks of forests may collapse in some places. These slides and gullies have the capability of causing damage from the ridge to the valley and hence are difficult to control.
- Thirdly, the debris generated by such erosion on the upper areas are going to get deposited on the fertile land of the valley and turn them onto waste land. Similarly, the debris on the river bed will raise the river bed causing changes in the direction of flow, which causes threats to the river banks. In the process the areas along the river far away from the EQ affected area may also get damaged.
Though water induced disasters such as floods and landslides are not new to us and we have the institutions and the expertise to deal with them, the landslides and gully erosion problems in the EQ affected areas will cover a large area and is likely to continue for some years to come on a bigger scale. The existing institutional setup does not have the capacity to work in such a big area at once. The technologies used in dealing with landslide and erosion control are not only expensive, but take a long time for implementation. Our institutional and technological capacity to deal with the expected scale of gullies, landslide and floods will be far less than required to face the challenge.
Damage to water sources
The other important source that the EQ has damaged in the hills and mountains is its water sources. With our limited knowledge of water science that operates in the mountains it is difficult to assess the damage caused to water sources. However, there are some indications of the damages. The readers may well remember there were reports about rise in discharge in springs, wells and streams in the valleys immediately after the earthquake. Wells and springs in areas such as Ramechhap, which have been suffering from drought for some years also saw rise in discharge. Wells in parts of Kathmandu saw increased level of water. Stone spouts that had gone dry for more than two decades began flowing. There were 2 to 3 times more water in some streams. Even in Panchkhal that has been reeling under drought for more than a decade now, the wells had increased discharge. Though the increased water brought happiness to the users, it is important to understand that the sudden and perhaps a momentary rise in water discharge is an indication of yet another crisis in waiting.
The increased water came when the aquifers in the upland leaked rapidly due to ruptures in the structures that held the aquifer. The aquifers that were supposed to provide water in a regulated manner were forced drained, which obviously increased water in the springs at lower elevations, but when the aquifer drains out completely there will sever water shortages in the upland. The springs will dry first. Dr. Ram Sharan Mahat [the finance minster] mentioned in his twit a similar instance of drying spring in the upper areas and excess water in his constituency in Nuwakot. The changes in the structures of the substrata of the mountains will affect the watersheds in their functions to regulate the hydrological cycle, which will affect the local water sources significantly. The time for which water will flow and the extent to which it is available at a particular place in the hills will eventually change the existing land and water relations. Opening of the new cracks and loss of old ones will shift the locations of the springs. Muzzafarabad in Pakistan experienced similar changes in the location of springs when the area was hit by the earthquake in 2005. What this means is that the water supply systems need to be reconstructed. Springs in the mountains have been drying since some years, and people in those areas have been displaced due to lack of water. With cases like drying of water sources in Nuwakot, we may expect many more to leave the mountains.
What can be done in the mean time?
It is a critical time. We need to start thinking about restoring land and water along with relief works. But there is hardly any time before the rainy season which is only two weeks away. After the monsoon begins it will be even more difficult to travel in the area. Nevertheless, some priority activities need to be done.
Of course, the first thing to do is to move people from hazardous areas to safe places. But it may not be possible to move all those people in hazardous places simply because of the large number of people to be moved. It is also likely that we may not get safe locations in all places. Therefore, we need to categorize the hazard level, and start thinking of measures to reduce hazard in areas that are not as hazardous. The local people can be asked to send information about land condition, which can then be matched with the expected rainfall to evaluate the hazard level.
It is very likely that in some places diverting monsoon runoff from the hazard areas can reduce the risk. People in South Lalitpur had done good work in reducing gully and landslide hazards by diverting monsoon runoff. Such experience may be useful at a time like this in the EQ affected area too. Reducing even a slight amount of the risks that people face would be a great relief.
However, restoring land and water must be a priority after the monsoon. It may be a long time before we realize the full extent of the damage caused by the earthquake to the mountains, the valleys and the streams; however, we may be in a position to assess the extent of damage caused to the land and water by next winter.
In the past, the State did not give the priority it deserved to help restore the resources when people were displaced after their productive land was converted into wasteland by floods and landslides or when the water sources in the hills dried up for various other reasons. But it does not have the luxury of turning a blind eye to the problem this time, because the problem is going to appear over a large area involving a large number of people.
Acknowledgement: Irene Upadhya for her support