Volume: VI Chapter: 3 Page No:
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Chapter 3: Physical and Biotic factors The total area of the Si Sub catchment is 32060 Ha. The Si Sub catchment has varied landforms, forest types, rainfall patterns, agro-ecological zones and soil types. This chapter gives an overview of the Si Sub catchment. The description of each parameter can be found in the Technical mapping chapter of this report.
Sub tropical broad leaved hill forest while 28% area is under Sub tropical pine forest.
1. Landforms The Landforms of Si Subcatchment represents that Si sub catchment has two types of landforms viz Steep to very steep high hills of Lesser Himalayas and Fluvial valleys. It is observed that maximum area i.e. 96% of the Si sub catchment is covered by Steep to very steep high hills of Lesser Himalayas while only 4% area is covered with Fluvial valleys.
2. Forest types The forest types that are present in the Si Sub-catchment shows that the area under Si Sub-catchment has 2 types of forests viz Sub tropical broad leaved hill forest and Sub-tropical pine forest. It is evident that 72% area of this Sub catchment is occupied by
3. Rainfall The pie diagram shows that the Si Sub catchment receives good rainfall. It is evident that Si sub catchment receives rainfall that has 3 ranges viz 1000-1500mm, 15002000mm and >2000mm. It is can be noted that maximum area i.e. 70% of the Si sub catchment receives rainfall that exceeds 2000mm.Whereas 26% area receives rainfall in the range of 1500-2000mm and merely 4% of the area receives rainfall in the range of 1000-1500mm.
Comprehensive CAT Plan of Satluj River Basin
Volume: VI Chapter: 3 Page No:
4. Agro-ecological zones Agro-ecological zones of Si Sub-catchment show that the Si Sub catchment has 2 types of Agro-ecological zones. The maximum area i.e. 99% of this Sub catchment is under the Agro-ecological zone described as Warm, Perhumid, Lesser Himalayas with 270-300 days LGP while only 1% area is under the Agro-ecological zone described as Humid/Perhumid, Lesser Himalayas with 300-330 LGP. 5. Soil types The soil types present in the Si Sub-catchment vary greatly. The Si sub catchment has heterogeneous soil with 5 different soil types. The diagram drawn below shows the distribution of different soil types in the Si Subcatchment.
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The Soil types 49, 55 and 60 occupy nearly the same area in this Sub catchment where Soil type 49 is present in 29% of the Sub catchment area. Whereas Soil types 55 and 60 occupy 33% and 31% area respectively. In addition, Soil types 37 and 27 cover 5% and 2% area respectively. Table A: Soil type description
Soil Description Shallow, somewhat excessively drained, mesic, coarse-loamy soils on moderate slopes with loamy surface and severe drained, fine-loamy soils with loamy surface and severe erosion. Shallow, somewhat excessively drained, thermic, loamy-skeletal soils on moderately steep slopes with loamy surface. Severe erosion and strong stoniness, associated erosion and strong stoniness, associated with Rock outcrops. Medium deep, well drained, thermic, fine loamy soils on moderately steep slopes with loamy surface, severe erosion and slight stoniness, associated with Shallow, well drained, fine-loamy soils with loamy surface and moderate erosion. Deep, well drained, thermic, fine-loamy soils on moderate slopes with loamy surface and moderate erosion, associated with Medium deep, well drained. Loamy-skeletal soils with loamy surface and severe erosion. Medium deep, well drained, thermic, fine- loamy soils on moderate slopes with loamy surface and severe erosion, associated Shallow, well drained, coarse-loamy soils with loamy surface, severe erosion and slight stoniness.
Note: The name of each soil types being very descriptive, we have denoted them as Soil types units. This nomenclature is used in the above diagram and also in the further explanation. The description of the soil types is presented in the table given below in table A.
Comprehensive CAT Plan of Satluj River Basin
Soil type unit
27
37
49
55
60