Impact Assessment of Watershed Development Programme A Case Study of Itagi Sub Watershed BY Mr. Palakshappa K Assistant Professor Department of Civil Engineering & STJ Institute of Technology Ranebennur 581 115 Dr. M. K. Nagaraj Assistant Professor Department of Applied Mechanics & Hydraulics N I T K Surathkal 575 025
Introduction Erratic and low rainfall, low fertility soils, poor infrastructure development, along with high population pressure with low literacy levels are some of the main causes of poverty in the semi arid tropics. High demographic pressure of one billion people in India and additional 519 million people are expected to be added by 2050. Furthermore 33% of the world s population mostly from developing countries including India will be affected by water scarcity by 2025.
Low productivity in dry lands and over exploitation of groundwater for irrigation has emerged as major problems in semi arid tropics (SAT) in India. WDP is implemented for in situ moisture conservation to improve productivity of dry land through judicious use of soil and water, agronomic practices, dry land horticulture, forestry, and other soil and water conservation measures. These result in restoration of ecological balance and improve the socio economic conditions of dry land farmers.
Watershed Development Programme (WDP) The Government of India (GOI) and state governments have adopted watershed management as a strategy to address the sustainable agricultural productivity in the rainfed areas since the last three decades. Further GOI has adopted watershed management as a national a policy since 2003 (Joshi et al. 2004). In the present study effect of rainwater harvesting structures on groundwater recharge and impact assessment of watershed development programme of Itagi sub watershed dis tk taken.
Study Area
The total area of watershed is 4636 hectares covering six villages viz. Magod (16.33%), Itagi (24.78%), Kamdodu (19.91%), Devagondanakatte (14.43%), Manakur (9.19%) and Mustur (15.36%). As per agriculture region and zones of Karnataka it is the northern transitional zone and soil type is shallow to medium black clay and red sandy loams.
The depth of the soil varies from 1.0 to 1.5 metres. The land slope varies 1-4 percent. Rainfed agriculture is the major economic activity of this area. Important crops grown here are maize, jowar, bajra, small millets, cotton, pulses, groundnut, and vegetables. The area receives an average annual rainfall of 683 mm. The maximum and minimum temperature of the area is 20 0 C and 38 0 C respectively.
Socio-economically farmers of the watershed area have poor economic base. The average land holding is 1.86 ha and it has to support on an average of six family members.
Soil and water conservation structures Soil and water conservation practices very rightly receive top priority for planning watershed management as they form the foundation for the sustainable agriculture. Water resource development stimulates all further developments in the watershed.
Watershed Action Plan for Itagi sub watershed (Details of soil and water conservation Structures) t Sl. No. Activity Physical Unit Financial Rs.(Lakhs) 1 Private Land Volume of Water storage (m 3 ) Contour Bund 1170 Hectares 163.6400 1881000 Recharge Pits 11 No. 2.0000 2376 Farm Ponds 131 No. 33.1040 64138 Loose Boulder Checks 138 No. 3.0720 Ravine 34 No. 10.2000 000 Reclamation Structures 10350 20400
Check Dam 10 No. 10.0000 Earthen Checks 1 No. 0.2500 Rubble Checks 342 No. 11.2770 Farm Forestry 303.33 Hectares 21.3550 Horticulture 218.06 Hectares 15.3440 Land Leveling 87.57 Hectares 11.1180 Vegetative Bunds 12.47 Hectares 0.0500 Waterways 112 Cubic.m 0.1390 Diversion Channel 2757 Cubic.m 0.7440 11250 350 48094 -- -- -- -- -- --
2 Common Land Black Plantation 104.98 Hectares 20.4600 -- Farm Ponds 1 No. 0.2500 432 RRS R.R.S 4 No. 1.2000 2400 Desilting of Tanks 4 No. 3.5750 15000 Check Dams 36 No. 25.6850 33750 Nala Stabilization 15.6 Cubic.m 0.9090 -- Farm Forestry 0.49 Hectares 0.1430 -- Road Side 14 Hectares 2.23502350 Plantation School Garden 0.5 Hectares 0.0500 -- 3 Administrative Cost ----- ----- 19.8130 Total 356.61306130 2089539 --
Results and Discussions. To study the impact of the watershed development programme (WDP) the data regarding, crops grown cultivation area of different crops, cropping pattern, productivity of crops etc., before and after the watershed development programme in kharif, rabi and summer season, were collected and analyzed.
Since rainfall is main source of water to the crops and as it varies over the years, the data of three years 2001, 2002 & 2003 are averaged and are taken and analyzed for pre-project period (i.e., before the watershed development) and the averages of the data of the years 2005, 2006 & 2007 are used to analyze the post-project p period (i.e., after implementation of watershed development). elopment)
Impact on Crop Area (Kharif Season) 4000 3500 3000 2500 2000 rea (ha) Ar 1500 1000 500 0 Maize Jow ar (Hybrid) Groundnut Onion Garlic Sunflow er Cotton (Jayadhar a) Vegetable Pulses Sericultur e Total Pre-project 702 453 450 356 245 512 584 68 124 23.3 3517.3 Post - project 894.7 345 365 380.33 272 428.7 708.3 130.5 111.8 70 3706.33 Kharif Crops
Impact on Crop Area (Rabi Season) 1200 1000 800 600 400 Area (ha) 200 0 Jowar(Rabi) Cotton (Niranjana)Gram Seteria Safflower Vegetable Pulses Total Pre- project 212 137 108 95 163 74 164 953 Post-project 261 158 142 102 156 128 138 1085 Rabi Crops
Impact on Crop Area (Summer Season) 600 500 400 300 200 Area (ha) 100 0 Vegetable Maize Groundnut Watermelon Total Pre-project 95 120 112 10 337 Post-project 158 162 142 18 480 Summer Crops
Impact on Productivity( Kharif Season) 140 120 100 80 Pro oductivity (q/ha) 60 40 20 0 Maize Jow ar (Hybrid) Groundnu t Onion Garlic Sunflowe r Cotton (Jayadhar a) Vegetable Pulses Sericultur e Pre-project 21 16 14 42 7 7 10 82 7 6 Post-project 30 20 18 60 9.5 9 13 120 10 8 Crops
Impact on Productivity (Rabi Season) 140 120 100 80 ctivity (q/ha) Produc 60 40 20 0 Jowar(Rabi) Cotton (Niranjana) Gram Seteria Safflower Vegetable Pulses Pre-project 10 8 9 7 7 100 8 Post-project 13 10 12 9 8 120 10 Rabi Crops
Impact on Productivity (Summer Season) 160 140 120 100 Produ uctivity (q/ha) 80 60 40 20 0 Vegetable Maize Groundnut Watermelon Pre-project 125 22 10 85 Post-project 145 32 14 120 Summer Crops
Crop Diversification A significant diversity of crops takes place as a result of availability of more water. Crop diversification over a period of time is measured using the Hirschman-Herfindahl diversification index. The diversification index can be calculated as given below. DIV = 1-HHI Where HHI is Hirschman-Herfindahl Index and is given by HHI= [Pit/ Pit] 2 Pit being the value of production at 2007 prices of the i-th crop in that year
Diversity it Index (Kharif Season) 1.01 1 0.99 0.98 Div 0.97 Pre-project Post-project 0.96 095 0.95 0.94 0.93 Mi Maize Jowar Cotton Groundnut Onion Garlic Sunflower (Hybrid) (Jayadhara) Vegetable Pulses Sericulture Pre-project 0.973 0.995 0.96 0.989 0.996 0.988 0.959 0.999 0.999 0.999 Post-project 0.9608 0.998 0.981 0.989 0.996 0.994 0.955 0.995 0.999 0.996 Kharif Crops
Diversity it Index (Rabi Season) 1.02 1 0.98 0.96 0.94 0.92 DIV 0.9 0.88 0.86 Jowar(L) Cotton (Niranjana) Gram Seteria Safflower Vegetable Pulses Pre-project 098 0.98 0.982 0983 0.983 0.999 0.968 0.958 0.967 Post-project 0.977 0.983 0.977 0.999 0.983 0.919 0.984 Rabi Crops
Diversity it Index (Summer Season) 1.2 1 0.8 DIV 0.6 0.4 0.2 0 Vegetable Maize Groundnut Watermelon Pre-project 0.705 0.963 0.949 0.998 Post-project 0704 0.704 0961 0.961 0957 0.957 0997 0.997 Summer Crops
Cost of production and benefits Gross retur ns Returns over TC Benefit cost ratio (BCR Value Fixed cost Variable cost Total cost Productivity (Rs./ (Rs./ (Rs./ (Rs./ (Rs./ Crops (q/ha) Rs../q ha) ha) ha) ha) ha) ) Pre project Maize 21.00 600 4200 14000 18200 12600 1400 0.90 Jowar 16.00 600 4200 13500 17700 9600 3900 071 0.71 Groundnut 14.00 1600 4500 19000 23500 22400 3400 1.18 Onion 42.00 400 5000 15000 20000 16800 1800 1.12 Garlic 7.00 2400 5000 16000 21000 16800 800 1.05 Sunflower 7.00 1800 4000 11500 15500 12600 1100 1.10 Cotton 10.00 1900 5000 17800 22800 19000 1200 1.07 Vegetable 82.00 400 5000 18000 23000 32800 14800 1.82 Pulses 7.00 2200 4500 13000 17500 15400 2400 1.18 Sericulture (Silkworm) 6.00 11000 10000 48600 58600 66000 7400 1.13
Post project Maize 30.0 800 4600 15000 19600 24000 4400 1.22 Jowar 20.00 800 4600 14000 18600 16000 2600 086 0.86 Groundnut 18.0 2000 5000 20000 25000 36000 11000 1.44 Onion 60.0 600 5200 17000 22200 36000 13800 1.62 Garlic 9.5 3000 5200 13000 18200 28500 10300 1.57 Sunflower 9.0 2200 4500 12000 16500 19800 3300 1.20 Cotton 13.0 2400 5200 18800 24000 31200 7200 1.30 Vegetable 120.0 600 5200 20000 25200 72000 46800 2.86 Pulses 10.0 2500 4700 13700 18400 25000 6600 1.36 Sericulture (Silkworm) 8.0 13000 10000 50200 60200 104000 43800 1.73
Change in B-C Ratio Values 3.5 3 2.5 o BC Rati 2 1.5 1 0.5 0 Maize Jow ar Groundnut Onion Garlic Sunflow er Cotton Vegetable Pulses Sericulture Pre- Project 0.9 0.71 1.18 1.12 1.05 1.1 1.07 1.82 1.18 1.13 Post-project 1.22 0.86 1.44 1.62 1.57 1.2 1.3 2.86 1.36 1.73 Crops
Improvement in the Groundwater recharge The natural groundwater recharge in the study area is about 9.82 percent After the WDP the groundwater recharge is estimated by monitoring i of the water levelsl in the wells located on upstream, middle stream and downstream of the watershed. It is found that groundwater recharge on the upstream, middle stream and downstream areas of the watershed are 14.31%, 17.28% and 20.21% respectively
The average improvement in the discharge is found to be 30.13 and 39.3535 percent in the upstream area of watershed for the years 2006 and 2007 over the year 2004. Similarly for the middle stream and downstream area itis35.10and48.80percent,and41.43and53.10 percent respectively
People s perceptions A set of questionnaires have been prepared and the sample households were asked about what they felt about the watershed development programme. As may be seen, from all the 8 micro watersheds of the study area in each of the micro watersheds, a minimum of 10% of the total households representing various socio-economic and user groups (marginal, small, medium and large farmers) are covered.
Conclusions. From the above results it is clear that, the watershed development programme in Itagi sub watershed are has following benefits. The land and water conservation activities have significantly improved the soil moisture conservation and thereby improving the crop productivity in all micro watersheds.
Soil erosion has considerably reduced (visibly) and percolation perceivably increased in arable lands as contour bunds have been taken up extensively in these areas. Improved groundwater recharge and yield of the wells brought more area under irrigation. Changes in the cropping pattern. Increase in the benefits cost ratio in the cultivation of crops.
Improvement in socio-economic condition of the people in watershed. The watershed development programme has a significant positive impact on creation of employment opportunities for the villagers, both landless as well as landowners Awareness among people and active people s participation in the programme.