Findings of Soil Conservation and Watershed Management Problems and Solutions In Chure Range of Nepal

 A travel from Amlekhgunj, Bara to Bhaise, Makwanpur in Nepal

19th August 2021, Sandesh gharti

This article gives information about Soil Conservation Engineering and Watershed Management in Nepal. The information I got from FOF, Hetauda my field visit to Siwalik range from Amlekhgunj, Bara to Bhaise, Makwanpur of Nepal.

Places where the problems of soil erosion and concrete and design were constructed to conserve the respective major problem in Chure region of Nepal.

Introduction

Soil conservation engineering and watershed management is one of the course subjects of the 5^th semester of the Bachelor of Science in Forestry. With regarding this course subject offered us practical knowledge through a one-day field visit to different places in order to discover the problems and solutions to erosion implied in Nepal.

The Siwalik hill of Nepal lies in between the two major thrusts; the Main Boundary Thrust and Main Frontal Thrust. Erosion has been a major problem all over the Siwalik range of Nepal which is one of the fragile geology of Nepal. It is necessary to analyze every aspect of erosion that has emerged as an effect of the land degradation problem of Nepal.

Erosion is of various types which are soil erosion, gulley erosion, water erosion, splash erosion, wind erosion, etc. Gulley-type erosion is the major issue of the Siwalik range due to fragile land topography.

Engineering and Bio-engineering structures are the major solution to the erosion problem which has been implied in several erosion-prone areas.

Findings

Observation no. 1:

In the figure, we can see the river is dry even though it’s monsoon season and the base is full of gravel and eroding banks of the river. The place shows the major problem of Chure i.e. gulley formation and the problem of eating backward which is increasing continuously due to runoff during monsoon heavy rainfall. This is located in the Chure/Siwalik range, the fragile geography of Nepal. On sideways of the gulley, there is Sal (Shorea robusta) forest. There was very little evidence of grazing. Like as shown in fig. 1 there are several other gulleys from smaller to larger ones on the bank of the river in, Northwest direction. There was no such evidence of developed soils or any layer of bedrock. Hence, analyzing all of this evidence, I have concluded that the weak geological condition can be regarded as the cause of gully formation in that area. Gulley erosion must be controlled in the river belt of the Siwalik ranges implying bio-engineering technique otherwise the fragile geology and human activities might cause a loss of biodiversity in the riverine area of Nepal.

Nearby the east-west highway, we observed the Gabion stone wall and Retaining wall to stabilize the highway. The height of that wall so as to decrease the pressure on the land surface it was designed to water which also helped to reduce soil erosion. The Gabion wall was established on only one side of the river bank at the highway-side, which indicated that the conservation measure has been applied in Nepal are focused only on development purposes.

Fig. 2: Gabion wall used for slope stabilization

Fig 3: Eroding environment bank and river with no water but gravel

        Fig. 4: Engineering structure constructed to control soil erosion

Observation no. 2:

We observed a historical tunnel which is the Churiya Mai tunnel that directly leads to Churiya Mai Temple. At that place, concrete slope stabilization work was going on by spraying cemented water on the slopes as shown in fig. 3 and there was no proper water drainage system. So, the slopes are susceptible to suffer from erosion.

Observation no. 3:

We observed a ladder-like concrete engineering structure that was preventing heavy erosion and landslide on the slope as shown in fig 3. The water flows slowly and protects from erosion. Besides the vegetation cover on that slope, an erosion problem was observed so to mitigate it the engineering structure was constructed in order to prevent the gully formation in that area to some extent. When rainfall occurs then the respective structure will function to prevent the surface from splash erosion.

Observation no. 4:

There was a narrow bridge of East-west highway. On one side of the river, there was Human Settlement and the local people were involved in Agricultural work. As the river is narrow, the depth of the river will be increased. During the monsoon period, the runoff increases so that there is a risk of river bank erosion and toe cutting. So, in order to prevent the problem of erosion, Bamboo and Sissoo plantation was carried out on the bank of the river nearby the settlement area. Bamboo (Poor man’s timber) has a great role in Bio-Engineering function and it grows quickly too in order to control erosion. Similarly, two spurs were provided in order to reduce the velocity of the river during flooding season. An embankment was also observed under the river extending sideways to protect the river bank from eroding. However, on the upstream sides, no spurs were provided which seems incomplete work for controlling erosion.

Observation no. 5:

We were told to divide into three groups, each group containing 5+ members, and then left free to collect information about the problems and solution measures of Soil and water conservation in the Bhaise area. Our group collected the data and facts by interviewing local people who were part of the disaster in the Bhaise area. We asked people some questions, regarding landslides and floods, and prepared a short story. One of the local people who lived there, Mr. Bir Bahadur Magar, who had worked for the Road department and now he has quit his job has told us that there was a massive flood during the rainy season in the year 2059. Also, frequent floods up to 2-2 times which had made a huge loss in the social and economic part of people’s life. Before 2059 B.S., the gully was connected to the river so fish used to migrate from the river to the upper eastern belts of that area. But after a huge flood, it broke the connection of the ecosystem and also destroyed the cultivated area. Recently, a check dam and a concrete road have been built to control erosion and mitigate floods. Also, we observed a sissoo plantation which was planted by people and is part of bio-engineering activity to control erosion by water and air.

Everyone presented their information obtained from key informant interviews and the session was quite informative to learn about the issues of the place.

   Fig 7.  Sissoo plantation for controlling riverside erosion 

Recommendation

Scientific research should be carried out for better control of gulley erosion in Nepal. Higher-level studies are necessary for the conservation of land from deterioration which decreases the bio-diversity of nature.