Thursday, October 3, 2019

Geological report on importance of rain water harvesting in selected areas of Ranchi city,India.

Dependency on groundwater for drinking and domestic purpose has increased.

By

Dr. Nitish Priyadarshi
Geologist.
nitish.priyadarshi@gmail.com


Introduction:

Water is essential for life- all living organisms contain water. In fact most living organisms consist of over 60 percent water.

Through out his brief history on earth, man has depended on three basic natural resources for his survival: air, land and water. Of these three, none has been more abused and neglected by man than water. Yet without water, the land produces nothing; without water, life vanishes from the face of the earth. Civilizations arose and have prospered for millennia where water was abundant. The Nile valley is a prime example. When water disappeared, civilizations withered and died. Mesopotamia is a classic example.

The utter human dependence on water is exemplified by the fact that man can survive for five weeks without food, but he dies after only five days without water. If the water supply of a human being is cut off for just a few days, he will die of dehydration long before the water is completely evaporated from his body. Water vapor is lost with every breath, and we cannot avoid breathing.
In recent years due to increasing contamination of surface water bodies, dependency on groundwater for drinking and domestic purpose has increased many fold. But these water sources are now badly affected with global warming. Groundwater is depleting day by day due to effect of rising temperature and urbanization.

The excess soil moisture that saturates subsurface soil or rock and migrates downward under the influence of gravity. In the literal sense, all water below the ground surface is groundwater; in hydrogeologic terms, however, the top of this saturated zone is called the water table, and the water below the water table is called groundwater.
Ranchi the capital city of Jharkhand state of India is located at 23.350 N and 85.330 E. The total area covered by Ranchi-Municipal area is about 141 square kilometers and the average elevation of the city is 645 m above Mean Sea Level (MSL). As of 2001 India census Ranchi had a population of 846,454.

Water supply, in adequate quantity and at desirable quality, is essential for any sustainable urbanization. Water supply in Ranchi dates back to more than 50 years ago.

There are three main dams ( Hatia, Rukka, and Kanke dam) from where the water is supplied to the city. Surface water is always vulnerable to pollution. People of Ranchi are dependent more on purer source like groundwater. Of the total consumption more than 60% comes from groundwater storage. Due to increasing population more pressure has developed on groundwater from the aquifer beneath the city.

The process of urbanization and industrialization from last 20 years has caused changes in the water table as a result of decreased recharge and increased withdrawal. Many of the small ponds which were main source of water in the surrounding areas are now filled for different construction purpose affecting the water table. Lots of DEEP- BORING in the Ranchi city has also forced the water table to move down as well as Ranchi plateau.

Groundwater in Ranchi city:

Groundwater in Ranchi city is mainly stored here in secondary porosity features or void spaces developed as result of weathering, fracturing, jointing, shearing or faulting phenomena. The gneisses and granitic rocks with associated schists and quartzites constitute the main consolidated rock terrain of Ranchi district.

Major portion of Ranchi city which is part of the Chotanagpur Plateau occupied by hard rock which are devoid of primary porosity and occurrence and movement of groundwater is controlled by the joints, fractures and fissures present in them.

During the long span of geological history these rocks have been deformed and tectonised in many ways including deep erosion.

In Ranchi city water table in the consolidated formations is now at its lowest from April to June. Water table is at its highest peak during August, gradually stabilizing in the month of November.

Sources of groundwater recharge in Ranchi city and the other parts of Jharkhand State is the vertical percolation of rain water. Although city experiences about 1000 to 1200 mm rainfall annually, the rate of vertical percolation is hindered by the presence of highly weathered and metamorphosed rocks. The Ranchi plateau gradually slopes down towards south east into the hilly and undulating region of Singhbhum. Due to this uneven topography the rain water are lost through surface runoff resulting in less water percolation below the surface. The thin soil layer of Ranchi plateau which is becoming more thin due to weathering is gradually loosing its water retaining capacity, Moreover, present land development practices in the recharge area and natural canals or rivulets in and around the city is also reducing the natural recharge significantly. More than 40% of the rain water is lost in the form of surface runoff. The rate of decline ranges between 1m/year to 5m/year at different observation locations within the city.
As Ranchi is becoming one of the important business center in Eastern India there is a rampant increase in construction and expansion of city. Due to inadequate water supply from the dams, dependency on ground water is increasing. Over pressed zones are Upper Bazar, Main Road, Ratu Road, Piska More, Chutia, Hindhpirhi, Circular Road, Burdwan Compound, Lalpur and Harmu Road.

Objective:
The main objectives of Rain Water Harvesting are:-
• Increasing the availability of ground water during periods of requirement.
•Preventing depletion of ground water reservoirs in areas of over exploitation.
Improving quality of ground water through dilution.

Rainwater harvesting is the collection, storage and injecting precipitation  down in the earth of  for later human use. This project focuses on the selection of the site and rainwater harvesting system located at the different rickshaw pullers garage located in different areas of Ratu road and Piska more in Ranchi city. The information collected  from this project will be used to build a template for designing a rain water harvesting system that can be placed in the selected areas.


                                    Fig.1 Depletion of ground water.


                                  Fig. 2. Structure of rain water harvesting.


Fig.3. Depleted water in a well in Piska More, Ranchi.

Rickshaw pullers are the most affected people as they are more dependent on surface and well water which is polluted and gets dry in summer season.


Till about thirty years back, the areas surveyed used to be unpaved and the rain falling on these areas would percolate into soil and remain there for being drawn through shallow open wells. With the proliferation of flat complexes, these areas been covered, resulting in stopping of percolation of rain water into the soil. But on the other hand the use of ground water has risen immensely. With Increase in the number of deep bore wells, the shallow wells started drying up. The reason is that no sincere attempt was made to re- establish the ground water table to its original level during monsoons.
Rooftop rain water harvesting was suggested in the surveyed areas. Out of 30 sites 10 sites were selected as the rickshaw pullers were using dug well waters for their daily purpose. Rooftop catchments is  the most basic form of this technology, rainwater is collected in simple vessels at the edge of the roof. Variations on this basic approach include collection of rainwater in gutters which drain to the collection vessel through down-pipes constructed for this purpose, and/or the diversion of rainwater from the gutters to the settling  tanks/percolation tank or absorption tank  filled with sands and cobbles and pebbles working as water filters. As the rooftop is the main catchment area, the amount and quality of rainwater collected depends on the area and type of roofing material. Reasonably pure rainwater can be collected from roofs constructed with galvanized corrugated iron, aluminum or asbestos cement sheets, tiles and slates.  Roofs with metallic paint or other coatings are not recommended as they may impart tastes or color to the collected water. Roof catchments should also be cleaned regularly to remove dust, leaves and bird droppings so as to maintain the quality of the water.
Settling tanks for collecting rainwater harvested using guttering may be either above or below the ground. Precautions required in the use of se tanks include provision of an adequate enclosure to minimize contamination from human, animal or other environmental contaminants, and a tight cover to prevent algal growth and the breeding of mosquitoes.




Sr.No
Garage Name
Garage owner name
Address
No.of rickshaw pullers staying  in the garage
Water Harvesting status
Remarks
Date of visit
1
Vijay
Vijay Tirkey
Near Krishi Bazar, Pandra, Ranchi
50
Yes; Important

29-01-2018
2
Amit
Amit kr. Bhagat
Piska More
70
Yes; Important

29-01-2018
3
SLK
Suresh Kachhap
Piska More
15
No
Shed not much and well is not owned by owner but garage owner has himself made some water harvesting system.
29-01-2018
4
Pawan
Pawan Sharma
Piska More
40
Yes

29-01-2018
5
BPK
Suresh
Karam toli
40
No
Has naturally available water resources which maintains the water level.
29-01-2018
6
JPB
Jagdish Bagla
Piska More
20
Yes; Important

30-01-2018
7
Guddu
Rajiv Agarwal
Near Uphar cinema, Ratu road
30
No
Consist of self built water system which maintains water level
30-01-2018
8
Mitu
Jayant Agarwal
Near Uphar cinema, Ratu road
30
No
Land too low so naturally land absorbs water, sheds are not available in much
30-01-2018
9
MPS
Madhukar Singh
Near Pahadi Mandir
25
No
No well; no boring and monthly rented land
30-01-2018
10
Sunil
Sunil Yadav
Near Pahadi Mandir
50
No
Less possibility of holding rain water
30-01-2018

Acknowledgement:
This survey was carried out with the help of Mrs. Aprajita Mishra and Smita Dasgupta of Maitri India, Ranchi.



Saturday, October 21, 2017

हिमालय से भी करोडो साल पुरानी हैं झारखण्ड की नदियाँ।

यहाँ की नदियां  करोडो साल पुरानी  होंगी। गंगा यमुना से भी बहुत पुरानी।    

द्वारा

डा. नितीश प्रियदर्शी

भूवैज्ञानिक



आज नदियों  अस्तित्व ही खतरे में है। सब जानते हैं कि नदियों के किनारे ही अनेक मानव सभ्यताओं का जन्म और विकास हुआ है। नदी तमाम मानव संस्कृतियों की जननी है। प्रकृति की गोद में रहने वाले हमारे पुरखे नदी-जल की अहमियत समझते थे। निश्चित ही यही कारण रहा होगा कि उन्होंने नदियों की महिमा में ग्रंथों तक की रचना कर दी और अनेक ग्रंथों-पुराणों में नदियों की महिमा का बखान कर दिया। भारत के महान पूर्वजों ने नदियों को अपनी मां और देवी स्वरूपा बताया है। नदियों के बिना मनुष्य का जीवन संभव नहीं है, इस सत्य को वे भली-भांति जानते थे। इसीलिए उन्होंने कई त्योहारों और मेलों की रचना ऐसी की है कि समय-समय पर समस्त भारतवासी नदी के महत्व को समझ सकें। नदियों से खुद को जोड़ सकें। नदियों के संरक्षण के लिए चिंतन कर सकें।    अगर नदियां ही नहीं रहेंगी तो मानव सभ्यता ही खतरे में पद जाएगी।  झारखण्ड में भी नदियों के अस्तित्व पर खतरा मंडरा रहा है।  नदियों का महत्व  जानना हो तो इसके इतिहास को भी जानना होगा की कैसे और कब झारखण्ड में नदियां अस्तित्व में आईं।  नदियों का जन्म एवं विकास एक लम्बी  कहानी है। हर नदियों का अपना एक उद्गम स्थल होता है। नदी का उद्गम पहाड़, जंगल आदि क्षेत्र में होता है। इनका जन्म यकायक नहीं होता, प्रत्युत्त क्रमबद्ध विधि से अनेक जलधाराएं मिलकर एक पूर्ण विकसित सरिता का रूप लेती है।  नदियों की उत्पत्ति कब हुई ये कहना बहुत मुश्किल है लेकिन संभावना व्यक्त की जा सकती है। अगर छोटानागपुर पठार  की बात करे तो ये प्राचीनतम चट्टानों से निर्मित है।  यहाँ के चट्टानों की आयु ६०० मिलियन वर्ष से भी अधिक है   तो यहाँ की नदियां भी करोडो साल पुरानी  होंगी। गंगा यमुना से भी बहुत पुरानी।    हिमालय बनने के बाद गंगा, यमुना इत्यादि नदियां अस्तित्व में आईं। झारखंड के पठार हिमालय से भी करोड़ों साल पुराने हैं।  हिमालय की उत्पत्ति आज से लगभग ५० से ६० मिलियन वर्ष पहले शुरू हुई जब भारतीय प्रायद्वीप तिब्बत के पठार से टकराया।  जब हिमालय बन रहा था उसी वक़्त झारखण्ड में भी काफी उथलपुथल हो रहा था।  वैसे हिमालये बनने के करोड़ों साल पहले भी यहाँ उथल पुथल हुआ था जिसका साक्ष्य यहाँ के चट्टानों में पड़े वलन से पता चलता है। आज से लगभग ४०० मिलियन वर्ष पहले डेवोनियन काल में झारखण्ड में दामोदर घाटी का निर्माण हुआ जहाँ से होके दामोदर नदी बहती है। इस काल को मत्स्य काल भी कहते हैं।  उस वक़्त पृथ्वी पर विशाल पर्वत बनने की प्रक्रिया चल रही थी।   चट्टानों में लम्बी दरारें पड़ी जो शायद आगे चल के नदियों के उद्गम में प्रमुख भूमिका निभाया। आज जो हम रांची के पठार की बनावट देख रहे हैं करोडो साल पहले ऐसी नहीं थी।  ये एक बेसिन था जो बाद में सेडीमेंट्स या अवसाद से भर गया   तथा बाद में एक पठार का रूप लिए और उसके बाद शायद स्वर्णरेखा, कोयल, कारो इत्यादि नदियों की उत्पत्ति हुई होगी।    हिमालय बनने के दौरान यहाँ ज्यादा ही उथल  पुथल  हुआ।  घाटियाँ बनी , कुछ भाग उठा तो कुछ भाग धंसा, जल प्रपात बने    छोटानागपुर की पठार की  नदियां या तो पहाड़  से निकली जैसे दामोदर या फिर धरती के नीचे से जैसे सवर्णरेखा। दामोदर नदी छोटानागपुर की पहाड़ियों से 610 मीटर की ऊँचाई से निकलकर लगभग 290 किलोमीटर झारखण्ड में प्रवाहित होने के बाद पश्चिम बंगाल में प्रवेश कर 240 किलोमीटर प्रवाहित होकर हुगली नदी में मिल जाती है। लेकिन देखा जाये तो सारी नदियां पृथ्वी के नीचे से दरारों से होती हुई ऊपर आईं।  हो सकता है की कुछ छोटी नदियों की उत्पत्ति ,हिमालय बनने के दौरान हुई      यहाँ की सारी नदियां बारिश के जल पर ही निर्भर हैं।  इतना तय है की छोटनागपुर पठार की नदियां करोड़ों  साल पुरानी  हैं। हिमालय से भी करोडो साल पुरानी।