Chapter 7. Design Decisions for Eco-Park
7.1 Site Analysis
The site analysis was done primarily by visiting the proposed area, mapping existing physical elements and validated with layering different maps available (Figure 7.1).
Figure 7.1: Existing land-use Validation by Visual Interpretation (Bhuvan NRSC, 2012) Satellite map 2009
Differences in land use pattern in all three proposed nodes were observed from various master plans by the State Government (Annexure 8). The extent of recreational areas proposed was validated and phase-wise implementation was suggested after comprehensive assessments done by exploratory observation and discussion with the agencies involved. Comparing the existing master plan, proposed DPR map (Figure 7.2), proposed master plan 2025 and notified and potential notified areas, the site area was analyzed for development (table 7.1).
Figure 7.2: Land-use map – DPR, Deepor Beel, 2012 page-16 Table 7.1: Existing Land use Validation: Visual Interpretation
In accordance with the findings from table 7.1, node one which is proposed for botanical garden and public recreational facilities is clear of any encroachment. As per the proposed DPR, Ecotel and other recreational facilities planned for nodes 2 and 3 will be developed through the PPP model. Node 2 with proposed recreation area was divided for Ecotel and resorts with cottages as approved in the DPR, along with public recreation facilities with PPP model. Node 3 is proposed with a detail layout plan for all water related recreational facilities, taking advantage of the water edges and proximity to the city limits. This can be implemented after the clarification of notified and potential notified areas. Nearly all the plots in this node are marked as notified and potential notified area (Annexure 8). In the meantime, as per the GMDA’s PPP model, facilities approved by State Government for all 3 nodes will be developed phase wise in the open available land pockets, leaving the existing houses for evacuation (Das, 2016).
Existing vegetation types are different in all three proposed zones. The core area has seasonal aquatic vegetation, protective buffer zone is composed of grass land and ground covers are covered with shrubs and plants with low canopy. The project management zone has tall trees acting as buffer (Figure 7.3).
Figure 7.3: Vegetation Type (Bhuvan NRSC, 2012)
There is an immediate need for the attention for the landscape regeneration for both forest cover adjacent to the wetland and water stream in the forest. Gulley control measures, with silt trap were suggested that is to be implemented by the Assam Forest Department, with proper engineering to minimize silt movement from hills to Deepor Beel. (P 8, Section 4-VII, DPR).
Figure 7.4: Contours and slope of surrounding hills (Bhuvan NRSC, 2012)
The contours on the south, in the hills are highly dissected for stone quarries and to be regenerated for its landscape (Figure 7.4). Contours for all three nodes indicate a slope of 5m to 7m from highway to the water body edges (Figure 7.5).
Figure7.5: Contour levels at all three nodes (generated using Contour Map Creator software) 7.1.1 Hydrology
NRSC has generated Annual flood inundation layer and flood hazard zone (Figure 7.6) for Assam based on the flood inundation, derived from various multi-date satellite data acquired during the flood season of 2010. Entry node 1 with a proposed Botanical Garden has low to very low flood hazard. Entry nodes 2 and 3 with proposed recreational facilities lies in moderate to low flood hazard zones. The boating areas selected (B) lies in the moderate to high flood hazard zones whereas the proposed constructed wetland (4) lies in moderate to low flood hazard zones.
Figure7.6: Flood Plain and Hazard Zoning (Bhuvan NRSC, 2012) 7.1.2 Soil type
The soil conditions are found as below (Figure 7.7 and Table 7.2):
Figure 7.7: Geomorphology 2005-2006 (Bhuvan NRSC, 2012) Table 7.2: Soil types in the proposed facilities
Proposed Site Location & Functions Accessibility Soil type Entry node 1, Chaygaon Guwahati road, S-W. (91°36'43"E 26°6'4"N) Boating-1, Nature interpretive center,
Botanical garden, Eco village(SW)
NH37 Azara Fluvial origin-older flood plain
Pamohi road (south)
Bird watching tower 2&3 and Elevated railway (elephant corridor)
Pamohi road Fluvial origin-old flood plain
Boating and Canoeing 2 Pamohi road Fluvial origin-active flood plain
Entry node 2, Tetelia, (91°40'31"E 26°7'44"N)
Ecotel and Active recreation area-1 NH37 Tetelia Highly dissected hills and valleys
Entry node 3, Jalukbari N-W. (91°38'11"E 26°8'19"N)
Active recreation area 2 NH37-
Jalukbari
Fluvial Origin-Older Alluvial Plain
Boating 3 NH37-
Jalukbari
Fluvial origin-active flood plain
Bird watching tower 4 NH37-
Jalukbari
Fluvial Origin-Older Alluvial Plain
7.1.3 Climate and environment
The climate of Guwahati is hot and humid during summer and dry in winter (Figure 7.9).
Average monthly temperature is 24.2°c (fairly hot) with highest average temperature in August (28.8°c) and lowest (17.1°c) in January. Average rainfall is1722 mm (67.8 inches), June-July being the maximum (309 – 377mm), (Figure 7.8). The city is situated near the sub-tropical moist forest biome (bioclimatic zone). Considering this, data for bioclimatic building design, and the shading devices should be designed for 60° to 84-87.3° (in Jun-Aug) sun angle in summer (Figure 7.8). Guwahati has one of the highest Black Carbon (BC) pollution levels in the world (ASTEC, 2018), due to rapid urbanization and poor environment quality control.
Figure7.8: Sun path diagram Guwahati (www.gaisma.com/en/location/guwahati.html)
Figure 7.9: Climate and Temperature, Guwahati (http://www.guwahati.climatemps.com/)