Watershed Management

The Baap Geog (administrative block) is located in the vicinity of the college of natural resources. The community faces an acute shortage both in drinking and irrigation water supply. The college has therefore initiated a study on the management of the watershed within the jurisdiction of the Geog. As per the land use data of 2000, the study site holds an area of 2608.894 hectares. The Geog has 406 households (Population and Housing Census, 2005), with a population of 3326 as of 2005. The main objective of the study is to discharge the College’s social responsibilities as an organization towards the local community, help the poor and needy to emerge out of the poverty cycle by facilitating income generating activities and provide a forum for the staff and students of the college to engage with the farming community.
While a preliminary geospatial study has been carried out, the ground-based study is yet to be done. The preliminary study on the watershed management was based on the land use base map of 2000, DEM derived from a contour map of 40 m interval and other physiographic digital maps of Bhutan 1997. The analyses of the data were done using GIS software, ArcGIS 9, version 2. The following criteria were used for the analyses:
1. No timber harvesting will be allowed within 40 meters of all water bodies (streams, springs, ponds, rivers) and 100 meters of buffer will be maintained alongside the motor-able roads.
2. No harvesting activities will be carried out in slopes above 50?.
3. Harvesting in broadleaved forest zones will be restricted
After the subtraction of land uses such as agricultural lands, wastelands, wetlands and settlement areas, the map of forests was derived.
The buffers around water bodies and road networks, and slopes beyond 50? were subtracted from the derivative forest map to obtain potentially harvestable forest areas.
In addition, the rapid geospatial study also assumed some parameters, such as the density of the forest and the demand of the farmers for the forest products. This was done in order to furnish the sustainable management of the forests by the farmers and application of appropriate silvicultural systems. From the assumed tree density and the farmers’ demand, the forest of the watershed area was found well beyond adequacy in the supply of forest products. However, as mentioned earlier, the ground-based study has to be carried out soon during which the real demand for forests products will be enumerated.
Presentation: Watershed Management.pdf2.2 MB