BRIEF REPORT ON HYDROGEOLOGICAL CONDITIONS OF DISTRICT THANE
GENERALThe importance and need of water in day to day life needs no emphasis. The demand for water is increasing in almost all sectors. The agriculture in most parts of the country depends upon the monsoon, which is confined to three or four months of the year. When monsoon fails, the rain fed crops also fail to yield good. The only reliable source then for agriculture is groundwater on which we have to depended upon for nearly eight months of the year.
The state of Maharashtra is one of the low ranking state in the country in as far as utilization of groundwater for irrigation is concerned, i.e because of its peculiar morphological and hydro geological set up.
INTRODUTIONKonkan Region marks the western boundary of the state of Maharashtra. The eastern side of the region is occupied by hill ranges known as ?Sahyadri? and western side is occupied by ?Arabian Sea? The region receives high rainfall It ranges between 3000-3500 mm. Thane is one of the districts of Konkan also falling in very high rainfall zone. Even then the district is facing shortage of drinking water in late summer because of its peculiar physiographic set up. The major portion of the rainwater goes as ?runoff.? An adverse geological strata also affects the poor storage of water in aquifers and less recharge due to heterogeneous nature of aquifers. The western portion of the district also have problem of potable water due to intrusion from sea water and creeks . LOCATION & EXTENTThane District is located on western strip of Maharashtra.. Towards north the district is bordered by Gujarat state. The eastern part is bordered by Nasik, Pune & Ahmadnagar districts & southern side by Raigad & Mumbai districts. The district comprises of 15 revenue talukas & the headquarter is Thane. The total area is 9558 sq.kms. The area lies between 18, 42, 00 : to 20, 20, 00. north latitudes and 72 45 00 to 73 48 00 east longitudes. The area ranges in altitude between 14 mts. to 35 mts. above with respect to m.s.l. The district is covered in between westerly flowing two river basins i.e. Vaitarna & Ulhas.
The total population of the district is 81.31 lakhs as per 2001census. The total number of villages are 1748. The Thane head quarter is well connected to all parts by metal roads & highways. The rail ways are well connected from thane to all other parts of the state. The major rural occupation is agriculture. The paddy crop is the major crop. However the horticulture can be seen in the coastal belt of the district. The town areas are mainly covered by small & medium scale industries & factories.
PHYSIOGRAPHYMorphologically the district has been classified in to three groups. a. Hilly & Foot hill region- Eastern part. b. Moderately dissected & sloping area- Central part. c. Coastal area- West part. DRAINAGEVaitarna and Ulhas are the two major rivers in the district. Vaitarna river enters east of Shahapur and flows westwards through Wada and Palghar debauching in to Arabian Sea. Pinjal,Surya, Deherje and Tansa are the tributaries of Vaitarna river. Ulhas river enters the district and debauches in to the Arabian Sea at Vasai creek. Bhatsa & Barvi rivers are the tributaries of Ulhas river. All river basins exhibit dendritic drainage pattern. RAINFALL & CLIMATEThe district receives an average of 3000mm. rainfall from South-West monsoon from June to Sept. every year. The climate of the district is generally hot & humid. The maximum & minimum temperature varies between 16? c to 42? c SOILSSoil types occurring in the district can be classified into four categories. a. Course shallow soils- occurs on the top hills occurs b. Medium deep grayish black soil- hilly slopes of estern part of district c. Deep black soils- occurs along the river plains of Vaitarnas Ulhas and its tributaries d. Coastal saline soils- occur along the costal strips GEOLOGYA major part of district is covered with basalt lava flows generally called as Deccan trap. This volcanic activity was confined mainly to Upper Cretaceous to Lower Eocene age. Besides Deccan traps the formation like local alluvium, beach sand, coastal alluvium, laterites, trachytes & rhyolite cover very small area of the district.
The main topographic features of this lava flows are flat topped hills and steps like terrace
Statigraphic sequences of the geological formation in the district is shown as below:-
Formation Age Lithology Alluvium Recent clay, silt and sand Beach sand Recent sand and silt Laterite Pleistocene Laterite Dykes --------- Basic intrusion Deccan traps basalt Eocene to upper cretaceous Amygdularbasalt Rhyolite Eocene to upper cretaceous Rhyolite Trachyte Eocene to upper cretaceous Trachyte STRUCTUREThe basalt flows are generally disposed and traversed by well developed sets of joints namely vertical & horizontal. The weathering activity is quite susceptible in the case of deccan traps. The depth of weathering varies from 3.00 to 6.00 mts. The common type of weathering is spheroidal weathering. HYDRO GEOLOGY:Hydro geologically the basaltic terrain has aquifers in the form of jointed and fractured trap. The occurrence of ground water in deccan trap is governed by its degree of weathering , concentration of joints & fractures planes, porosity & permeability of geological units. The movement & storage of ground water are mainly controlled by physical & geological set up of the terrain. The lava flows have no primary porosity. Only after weathering the cracks develop which allow ground water to store . However due to adverse morphological conditions , the availability of ground water is mainly restricted to plains & valley fill. The irrigation based on ground water is seen only in the parts of Dahanu, Talasari, Vasai, & Palghar tahsils. The irrigation is mainly of horticultural crops. The coastal sandy aquifers are sufficiently good yielding, but even a marginal over exploitation causes intrusion of saline water.
For monitoring of ground water levels 92 nos. of observation wells have been set up in 34 nos. of elementary watersheds. The manual monitoring of static water levels is being carried out four times in a year. The water level data collected are useful for ground water assessment and planning for future groundwater development. The water table fluctuations in the observation wells vary from terrain to terrain. In coastal area water level fluctuations range between 1.00 to 4.00 m. where as water level fluctuations range between 4.0 to 7.0m. in hilly areas.
CROPPING PATTERNThe main crops growing in the district are paddy, vegetables, dal, Turi, Varai, etc Further in coastal parts coconut , betel nut, chikku ,flowers etc are the main crops. The Wada coloum called leoni is very famous rice cultivation in Wada taluka. CULTURAL ACTIVITIESIn the district out of 15 talukas, 7 talukas are covered by tribal Community, mainly by varlies, konkanies, kunbis, Parsees etc. the coastal parts of tribal talukas are partially covered by koli, Agri ,Agri koli, Gujaratis, Christians, etc. Some taluks partially covered by Buddhists,Muslims, etc. The cultural activity of tribal community is folk dances. The Katkaris and Thakurs have mixed group dances .usually conducted in festivals like Holi, Diwali, Sankranti, Dasera .The dance commences with the Dholya beatng the drum and dancers gathering round in circle. the Khelya sings out a line of a song which is then repeated by the group .These type of dances are very famous in tribal talukas bordered by Gujaratis ,Christians. COMMON FESTIVALSHoli Ganeshchaturti, Sankranti, Deepavali, Raksha Bandan. The new moon day of Shrawan month is called as Narli poornima , On this day Koli community worship sea and starts fishery work. The Holi festival is most important in tribal community. Historically Vasai fort, Arnala fort, Jawhar Rajwada, and Vajreshwari are famous tourist places. HOT SPRINGSThere are 40 nos of hot springs in the area of Bhiwandi and Palghar talukas especially in Vajreshwari, Sativali, Haloli, Paduspada and Koknere. The temperature of these springs vary from 30? c to 70? c. Most of the hot springs are seen on the frings of dykes.