GROUND WATER LEVEL MONITORING

NATIONAL HYDROGRAPH NETWORK MONITORING PROGRAMME

Introduction

CONCEPT OF MONITORING STATIONS

SELECTION OF OBSERVATION SITES

DISTRICTWISE STATUS OF NHNS IN UTTAR PRADESH

Construction of Piezometers on Contractual basis for Long Term water level monitoring:

Introduction

             The Central Ground Water Board, Northern Region closely monitors the ground water situation countrywide through 1200 national hydrograph network stations. It monitors changes in water levels through these stations 4 times a year (Jan/May/Aug/Nov) and collects water samples once a year in May for water quality analysis. The data so generated by these network stations are used to prepare maps of ground water level changes for the whole state. The data is used to generate long term water level trend which help mapping the area prone to ground water over-development.

CONCEPT OF MONITORING STATIONS

              Board has drilled more than 500 boreholes, in the depth range of 200 to 700m in Utter Pradesh. Interpretation of the geophysical logs of boreholes have unraveled a large tract of brackish/saline to marginally fresh groundwater in the Central Ganga Plain. The water quality deterioration is regionally correlatable all along 700 kms run from Meerut in northwest to Ghazipur in southeast. The deteriorated quality groundwater is found mostly sandwiched between impermeable clays with fresh water occurring above and below. As an exception in southern and southwestern fringe brackish/saline groundwater once sets in at the water table, continues up to bedrock occurring around 200m bgl. The maximum thickness of brackish/saline groundwater column is found in Ghaziabad, Aligarh, Agra, Mathura, Hathras, Firozabad, Etawah and Fatehpur - the most affected districts in proximity of the river Yamuna. The groundwater quality assessment from geophysical logs has been an invaluable information in targeting fresh water horizons for sustainable groundwater development.

SELECTION OF OBSERVATION SITES

            The basic principles for the location of monitoring wells are as follows :

1.Should be based on geo-hydrological, social and economical considerations. Optimal design should include assessment of the density of the network through statistical algorithms which needs to be adjusted based on geo-hydrological conditions and monitoring objectives.

2. Local area conditions. The data collected should be unbiased and not subjected to interference from production wells, canals or surface water bodies in the neighbourhood.

3. Site should be accessible throughout the year

DISTRICTWISE STATUS OF NHNS IN UTTAR PRADESH