Volume I: Part I: Section 2: Chapter 1
2.1.1
Section 2: Task A: Creation of Baseline Data Chapter 1: NERIL’S approach to the Terms of Reference UNIT OF STUDY: The unit of study for preparation of this CAT Plan is a MICRO WATERSHED (changed from beat to MWS). This unit was chosen because it was the smallest geographical unit contributing to erosion.
earth surface generated by precipitation (Rain and Snow melt) and controlled by gravitational force. Hydrological cycle define the movement of water on the earth surface.
Evaporation from sea--- Formation of clouds---Clouds generate rainfall---Rain water moves from hills towards the sea----some enter the soil--- some evaporate back to atmosphere from soil and plants---- and major part goes back to sea. The cycle continues in nature and modified by climate. In tropical and sub-tropical regions, monsoonal pattern of hydrological cycle operate—most rains occur in 3months followed by small showers, but floods and droughts are common
The reason for this choice is that it is the smallest natural unit which is affected by water and silt transport. This concept is explained in further details here under:
The rain or snow melt flows down the mountain slopes on either side of the ridge line in small streams flowing down and joining together at the bottom of the valley / gully as illustrated below.
Subject of water (H2O) is covered under the discipline of Hydrology. It has two main branches: Surface hydrology and Sub-surface hydrology (Geo-hydrology): Surface hydrology deals with water flow on
Comprehensive CAT Plan of Satluj River Basin
Volume I: Part I: Section 2: Chapter 1
The intensity of rain / snow melt, steepness of hill sides, and the nature of the top soil, vegetation, human interference, grazing and many such factors combine to erode the surface
2.1.2
soil and carry it away in the form of silt load. The different problems of a catchment area can be categorized and analysed as illustrated in the next illustration.
Comprehensive CAT Plan of Satluj River Basin
Volume I: Part I: Section 2: Chapter 1
2.1.3
(Illustrations and text Credits Dr. SS Grewal & Dr.Dogra)
In order to address these problem areas, we need to apply appropriate technological interventions to the current situation so as to minimize / nullify the problems. These interventions are categorized in the illustration on the next page. It can be seen that the technological interventions relate to slope management, drainage line treatments and problem areas needing special treatments. NERIL therefore decided to carry out detailed survey of every MWs
to identify soil erosion and siltation related problems. The survey methodology was selected to suit this intention. It would be apt to state that application of appropriate technological intervention was also selected at the level of MWs based on what was found to be most appropriate intervention to arrest further degradation or to reverse and rectify degraded area. This approach is illustrated in the schematic diagram of the typically treated watershed drawn after the illustration on the next page.
Comprehensive CAT Plan of Satluj River Basin
Volume I: Part I: Section 2: Chapter 1
Comprehensive CAT Plan of Satluj River Basin
2.1.4
Volume I: Part I: Section 2: Chapter 1 Delineation of Satluj Catchment in Himachal Pradesh The nomenclature of sub catchments (SC) and micro-watershed (MWs) is according to nomenclatures provided by All India Land Use and Soil Survey. However such nomenclature for Spiti valley and for the area between Wangtoo to upper Kinnaur is yet to be done therefore nomenclature is provided by the Himachal Pradesh Krishi Vishwa Vidyalaya (HPKVV) is used. The total catchment of Spiti and Satluj is therefore divided in SC and MWs as tabulated below:
•
We have promoted time tested, proven and recommended technologies after review of success or failure of the lessons learnt from the implementation of the previous projects.
•
Our approach is basically to control degradation of land, water and vegetation resources by improving forest cover by conserving the existing ecosystem and addressing the environmental concerns.
•
Our approach is consistent with central and state forest policies to facilitate participatory implementation of the project programmes.
Approach and Methodology •
We have adopted watershed concept / philosophy as specified by the GOI and National Rain fed Area authority and state guidelines.
•
We have adopted integrated, participatory, process based; bottom up approach for social development and top down for technology adoption.
2.1.5
Locations
Sub-catchments
Micro-Watershed
Kol dam to Wangtoo
10
179
Wangtoo to upper Kinnaur
23
Not delineated
Spiti
8
Not delineated
Total
41
Comprehensive CAT Plan of Satluj River Basin
Volume I: Part I: Section 2: Chapter 1
2.1.6
Satluj basin map with Micro-watershed and sub-catchment boundaries
Comprehensive CAT Plan of Satluj River Basin