Volume I: Part I: Section 4: Chapter 2
4.2.1
Section 4: Chapter 2: Survey Methodology and coverage Surveys using checklist method (Please refer annexure No.s (a)1, (a)2 and (a)3 for check lists) Accuracy and uniformity of obtained data is very important for the assessment of the current situation. In order to avoid any subjectivity, NERIL prepared a set of 14 checklists. We prepared checklists for each microwatershed (Refer check lists table Nos.
1 to 9), as well as for the community development blocks (CD Blocks). (Refer check list table Nos.10 to 14). The procedures and expertise for obtaining these data for microwatersheds were different than those for the CD blocks. It is diagrammatically shown below:
Comprehensive CAT Plan of Satluj River Basin
Volume I: Part I: Section 4: Chapter 2
2.1
Sample Survey
Looking at the topography of the area it was evident that site verification is a very important task in this Himalayan region. Vintage of the available maps, and shadow regions in imagery, were identified as the limitations for reaching the desired accuracy of findings and prescriptions. The need to
4.2.2
have a record of first hand stake holders consultations together with the need to prepare an actionable CAT plan resulted in 100 % field survey. Thus NERIL in consultation with the HPFD formulated the sampling size for the degree of accuracy required to arrive at accurate findings. Details of the sample size are provided below:
2.1.1 Sample size for the survey of Comprehensive CAT Plan of Satluj River Basin
Volume I: Part I: Section 4: Chapter 2 CD blocks: In each CD block sampling of villages were carried out based on this criteria. Household sampling was done based on their landholding and the classification is provided below: Landholding
Classification
Landless
Nil
Less than 1 Ha
Marginal
1Ha -2 Ha
Small
More than 2 Ha
Large
Based on above classification and secondary data number of households was selected for sampling.
2.2
Silt sampling sites:
List of 52 sampling sites were finalised and submitted at the inception stage. But later on as the understanding about the project area increased it was increased to 62. As mentioned in ToR NERIL was to take silt samples in 15 days in monsoon and based on these results, the readings for high silt yielding micro-watershed at the end of monsoon were to be taken again. This was to be done to understand which micro-watershed render more silt into the river. After readings of 2009 monsoon season were taken, the analysis suggested that due to sub normal rain in that year may provide erroneous result. The data for these sites were obtained in 2010 again the analysis suggested that top 10 sites yielding high silt were all
4.2.3 from sub-catchment where microwatershed delineation was not completed. In other words these sites were from Kinnaur, Spiti, the upper, regions of Satluj catchment.
2.3
Survey Methodology
In order to procure accurate information NERIL had formulated the checklists (Refer Annexure (a)1 ). Socio economic and agronomical aspects like agriculture, horticulture, vegetable crops and livestock which affect and get affected by catchment are dealt at CD block level. Therefore this kind of data was collected at block level. The checklist for the same is attached at (Refer Annexure (a)2 ). These checklists were analysed and the analysis sheet was sent to the expert for their analysis, selection of sites to be visited by experts and for report writing. The analysis sheets are placed at (Refer Annexure (a)3 ).
2.1.2 Field verification by Expert Base on the primary and secondary data collected and its analysis, the NERIL experts selected the sample locations for quality control and for on site assessment visits. The locations visited by the experts are highlighted in yellow in the maps given below:
Comprehensive CAT Plan of Satluj River Basin
Volume I: Part I: Section 4: Chapter 2
4.2.4
34% micro-watershed visited
Sub-catchment visited in Kinnaur region
Comprehensive CAT Plan of Satluj River Basin
Volume I: Part I: Section 4: Chapter 2
4.2.5
Sub-catchments visited in Spiti region
Comprehensive CAT Plan of Satluj River Basin