Delhi ridge | ravindrabhan

NEW DELHI RIDGE PROJECT

An Environmental Study

ECOLOGICAL PLANNING OF DELHI RIDGE

Urban environment in our large cities has been deteriorating at an unprecedented pace. The paradox and tragedy of metropolitan growth and sub-urbanization is that it destroys many of its objectives. The open countryside is subject to uncontrolled sporadic, up-coordinated, unplanned development, representing the sum of isolated short term decisions of little taste or skill. Nature recedes under this careless assault, to be replaced usually by growing islands of development. These quickly coalesce into a mass of low grade urban sprowl which eliminates all natural beauty and diminishes excellence, both historic and natural.

In recent years, we have come to realize the ill effects of poorly planned area. We cannot afford any more to repeat our past mistakes the scale has grown too big and affects too many people.

Most of our problems are a result of near total disregard of natural environment and refusal to respect and work within the limitations of this environment. Basing development upon economic and social criteria alone has proved to be inefficient and destructive in the long run. Man is part of total environment. Environment is a part complex interacting system. The healthy environment of a place is a proper mix of natural and man-made components of environment. Although this fact is well known but still the very planning processes which have developed sophisticated methodology for taking into account the man made components of environment have either shown near disregard or have not integrated into a meaningful way the components of natural environment into planning methodology, which consequently have resulted in degradation of environment.

Environment is complex entity having a limited carrying capacity. It can be comprehended, predicted and managed. Its adaptability is limited and can only take man’s abuse up to a certain level. If the limits of its tolerance are stretched beyond carrying capacity the changes are irreversible and the very adaptability of environment is broken resulting in total imbalance and its destruction.

Natural and man-made environment are complementary and interdependent on each other. The quality of life of any existing or planned development depends solely on preservation of vital elements of environment and their proper management. Development depends solely on preservation of vital elements of environment and their proper management. Development strategies which take only into account the immediate shot term economic gains have proved disastrous in the long run causing irreparable injury to human health and well being.

The basic concept behind economical planning is to understanding nature of a place by analyzing its bio-physical components such as climate, geology, physiographic, hydrology, soils, vegetation and wildlife, establishing the inter-relationship of these bio-physical components to each other and there ascertaining the tolerance and intolerance of the components to man-made demands of land use and finally arriving at a healthy compromise whereby all the bio-physical components and existing development function properly and sustain all planned demands.

Delhi Ridge is a major open space in Delhi. The area is very rich in biodiversity and a unique asset for the growing population of Delhi.

If this biodiversity is to be maintained the planning of the ridge as a potential recreation resource has to be understood in terms of its fragile eco-system and planned in such a way that the very character of this place is preserved and enriched.

To demonstrate the methodology of ecological planning a study of the part of Delhi Ridge namely central ridge covering an area of 864 hectares was conducted by Prof. Ravindra Bhan in 1974. The area was mapped for various ecological parameters (maps attached) and final synthesis map arrived at showing areas of active to most passive recreation zones in the central ridge area.

MAP 1

The area was maped for its micro-climate variations. The darker tone of the color indicates less stressful area in terms of temperature than the lighter tone. The variation in temperature between dark and light tone areas was 4 to 5 degrees Celsius.

MAP 2

Depth to bedrock

Soil has not developed fully in the ridge area. Black colour on the map shows rock outcrop. The subsequent four further gradation of color indicate soil depth as follows:

Less than 2 feet, between 2-3 feet, 3-5 feet and above 5 feet

MAP 3

By types

There is a variation of soil on the ridge. Shown from red to pale yellow. Red indicates rock outcrop. The four variations are gravelly soil, coarse sand, fine sand and fine sandy loam.

MAP 4

Physiography

Aspects show the maximum warm areas south facing in dark color to minimum warm areas that is north facing. In between following variations are shown:

SE/SW, flat areas, EW/NW and North aspect. The variation of temperature on these aspects varies between 4-5 degree Celsius.

MAP 5

Hydrology

The map shows the five drainage characteristics. Regular drainage on 0-3% slope 0-5% slope, above 5% slope and irregular drainage on slope and above 5% slope.

MAP 6

Hydrology

The map shows the major drainage divides with solid lines, major water sheds with thick dotted lines channel order that is further sub division of drainage lines.

Four drainage patterns with their characteristics are shown.

Dendritic Drainage occurring on uniform rock and soil.

Rectangular Drainage occurs on fractured bed rock.

Centripedal Drainage happens on high permeable areas with porous rock and parallel drainage on uniform slope with faults and fracture in bed rock.

MAP 7

Vegetation

Density as existing on site

The present vegetation character of ridge was measured under five categories from dark to light colour tone.

Very dense over 90%

Dense 75% to 90%

Medium dense 50% to 75%

Sparce 25% to 50%

Poor less than 25% and areas on no vegetation.

MAP 8

Vegetation

Density potential if the area is protected and managed

Reading the map from dark to light colour tone

Dense vegetation 80% to 90%

Medium Vegetation 30% to 45%

Sparce Vegetation 25% to 35%

Poor Vegetation 20% to 25%

Very poor vegetation covers less than 20%

MAP 9

Wildlife

Potential habitat

The map show fine zones very dark tone good for birds and mammals. Second dark tone fair for all birds, yellow ochre poor area for birds, light yellow area affected by noise pollution. Very light yellow area pond or depressions with water which has potential for aquatic life.

MAP 10

Pollution

Noise stress

Noise levels on roads, intersections, adjacent areas were measured in terms of decibel rating. Three zones were mapped from pink colour. Minimum stress zone below 50 dBa. Intermediate stess zone 50dBa to 70 dBa. Maximum stress zone above 70 dBa.

MAP 11

Visual Analysis

The total area is divided into water sheds and each water shed shows the physiographic and visual characteristics of the area.

MAP 12

Associated Plant Communities

In valleys

Due to micro-climate variations plant species develop differently.

MAP 13

Hydrology

Geo-Physio Units

Map shows response of hydrology, geology and physiography on various water sheds and bring out their characteristics.

MAP 14

Identification of Drainage Basin

The map of a water shed shows that with only detailed hydrological data and its characteristics for a typical drainage basin it should be possible to predict land forms, geology, soils, hydrology and vegetation. Thus substantiating the idea of ecological inter-relationships of natural system.

MAP 15

Synthesis of Recreational Suitability

The map is a combination of all the ecological parameters which has been maped. All the relevant characteristics are taken into account for active and passive recreation land uses so that they are ecologically compatible and self sustainable for passive and active recreational development.

The darkest tone in the map shows the gradation for most passive use to only active use which is shown with pale yellow colour.