Belgaum Urban & suburban area, Karnataka State.
Longitude 74º30’ and Latitude 15º 51’.
The city is distributed in 3 river catchments namely Bellary Nala catchment (53,35%), Markandeya river catchment (31.65%) and Mongetri Nala catchment (14.98%).
To review the status of water resources (quality and quantity wise) of Belgaum Urban & suburban areas.
Urban expansion indeed, has put enormous stress on various resources. The most fundamental necessities for urban expansion are space raw materials, energy, water supply and waste disposal sites. The water resource development plays an important role in achieving the multifaceted growth. The water supply relative to ever-increasing water demands is declining and sooner or later the water resources will be in short supply with respect to the demands. Therefore, there is a need for planning of river basin systems in a manner that would lead to full and comprehensive development of total resources of the basins.
Available literature from National Institute of Hydrology, Central Groundwater Board, Mines & Geology Groundwater Unit, NRDMS Center.
Study of some locations by field survey.
Data collected from district Statistical Office, Irrigation department and State Mines and Geology department.
The Belgaum City has elevated portions towards north, west and south with open eastern part. The central and eastern portion is almost silted with black cotton soil owing to weathering and erosion. The drainage generally follows east.
The area comprises of black soil, red soil, laterites, weathered basalt, and Proterozoic (Kaladgi) sedimentary rocks. The laterite and weathered basalt are the only litho units that are water bearing.The annual rainfall in Belgaum City is 1031 mm. The study area recorded an annual rainfall deficit of the order 30% in the year 1985 and 1990. The study area has a probability of getting rainfall is 75% or more in the group ranges between 750 mm and 800 mm. In Belgaum taluks, there are number of tanks, which are playing a big role. About 1000 ha of land can be irrigated by conserving the water in tanks. Belgaum City, the solid waste amounts to about 80 tonnes per day. Water contamination, air pollution and anaesthetic conditions in the vicinity of the dumpsites are a common problem. The most damaging waste is in the form of sewage.
Public of Belgaum City complained about mixing up of sewage water to their wells. The water samples were collected and got analyzed
). The Ground water analysis by the previous researchers, for the Belgaum City area shows concentrations of various constituents within the permissible limits. However, higher values of sodium and potassium are reported in many of the samples which is attributed to sewage water pollution and fertilizers used in the area Almost all the samples show high to very high values of total hardness. In few localities nitrate concentration is also seen. Most of the wells, which are showing higher concentration of contaminants, is mainly in the unused wells. Renovation and utilisation of the ground water will improve the quality of the water. However, in some of the wells the concentration of sodium is higher than the values reported from other parts of the city.
Stratigraphically, mostly weathered rocks except in certain patches cover the area. It is expected that less weathered zones is capable of releasing good quantity of major cat ions such as Na, K, Ca, Mg and SiO2 and on weathering rarely sulphates. As it is evident from the available data, the distribution pattern of chemical elements indicates its origin from various geochemical environments. For the bicarbonates the source is carbon dioxide released by plant roots and the decomposing organic matter in soils. The weathering action of carbon dioxide on primary minerals can be described as a breakdown of the silicate with release of the cations which will appear as bicarbonates. As the bicarbonates concentration increases, the breakdown of primary minerals decreases despite the high carbon dioxide pressure. The reason for this is the increasing pH following the increase in bicarbonates. The weathering is very slow at pH value between 7-8, judging from the chemistry of groundwater in crystalline rock areas.. This is true in the present case as in most of the observations, the pH value falls between 7-8. Chemical weathering is mostly completed before the water reaches the groundwater table.
The study carried out by GIT (1996) shows that, the groundwater from the borewells possesses carbonate hardness, which exceeds 50%, i.e., alkaline earth and weak acids dominate chemical properties. The ground waters are non- corrosive and belong to rock dominance class (Gibbs, 1970). It was observed that, groundwater from most of the places in the city are highly contaminated. From figure
), it is clear that, the groundwater samples lie in the rock dominance field. The study reveals that the quality of groundwater is affected by the parent rock/ aquifer. Here the plots are made against the ratio of (Na/Na + Ca) and (Cl/Cl – HCO3) to know the mechanism controlling the chemistry of groundwater. Generally, C1-S1 and C2-S1 is said to be of good quality, C1-S2, C2-S2, C3-S2 and C2-S1 tolerable quality and the rest are of bad quality. Water samples for the present study area shows that most of the samples lie within the S1 and S2 category and salinity zone lies in C1 to C3 zone.
The wastage of water, which amounts to about 20% delivered, should be brought under control by replacing the pipelines, which are old and damaged. These would also reduce the often noticed intermixing of sewage with drinking supplies. The city drainage should be diverted through lined gutters or pipes to the treatment plants to protect local health and hygiene besides shallow groundwater. There is a need to recognize the rapid rate at which ground water pollution is taking place at present.
Date of project completion:
17 February 2000
Total Cost of Project:
19,166=25 (Nineteen Thousand One Hundred Sixty Six and paise 25 only).
M.Sc., M.Phil., Ph.D.
Sr.Sc.Lecturer, Dept. of Geology,
BELGAUM – 590 006 INDIA
Ph: (0831)484085, 485193(O); 485069(R)