Project Title:
An Integrated sustainable management of two microwatersheds in Manipur.

Thematic Area:
Water Shed Management

Location: (Figure 1)
Awang Khujairok watershed:
* Latitude: 24.69 N to 24.72 N 
* Longitude: 93.74E to 93.77 E
* Covers an area of 6.489 sq. km in Senapati (Manipur)
Waikhulok watershed:
* Latitude: 24.82 N to 24.84 N 
* Longitude: 93.77 E to 93.79E
* Covers an area of 3.857sq.km in Senapati (Manipur)

Objective:
* To generate a hydrological database of two microwatersheds in Manipur
* To prepare a GIS database on the natural resources of the watersheds
* To analyze the hydrological conditions of the watersheds by water balance studies
* Water budget in the area to project the future land use plans in the watersheds
* The collect live stock of the surrounding villages for water requirement and to develop the GIS layer plan for microwatersheds
* To regionalize the agro climatic conditions for other areas, based on the outcome of the studies 

Abstract:
Considering the vital importance of the microwatershed approach in various agro climatic regions of the country, two microwatersheds have been selected in Manipur to study the hydrology, meteorology, soil and water conservation strategies and socio-economic factors. In order to collect the hydrological data, the watersheds were instrumented, and a hydrological database was created for a period of three years for the Awang khujairok and Waikhulok watersheds. These watersheds cover an area of approximately 500 ha, which constituted a part of the Loktak Lake. The database was used to compute the hydrological parameters. A GIS layer was also generated for the different natural resources of the watersheds. The socio-economic parameters were used in the studies for assessing the sustainability factor. The use of AV-SWAT 2000 is found very successful for predicting the different scenarios in the watersheds. However, the Streamflow of these hilly watersheds was not very close to the predicted value using SWAT software. There is a possibility for unaccounted water to enter the watershed, which has not considered in the existing database. The existing database is the only baseline data at a microwatershed level in the typical agro climatic region at NE India.
The village authorities are being contacted for technology transfer for their local area planning .The findings of the studies are being rationalized by identifying identical geomorphic, hydrologic and geologic regions. The outcome is useful to transfer the NRDMS technology related to the watershed management in similar agro climatic regions.

Highlights/Findings:
* Physio-Chemical Analysis: (Table1)
* Reduced level of water surface:
The ground water level fluctuates around to the minimum of 817.300 m during the lean season and it goes up to around 818.250m during the wet season. But it is observed that the ground water level is found to be decreased during the wet season in the last two years when compared to the previous.
* Water balance studies: 
During the wet season, the water losses due to the interception. Percolation and surface detention come above the balance level. But, it has been observed that the water losses by these interception, percolation and the surface detention goes down near or below the balanced level in some dry months of the year though the water availability from the surface and the ground water sources is quite plenty. The Streamflow of the watersheds was not very close to the predicted value using the SWAT software. Reason may be the unaccounted water to enter the watersheds, which has not considered in the existing database. Recently, some springs are discovered in both the watersheds, which might have been the main factor.
* Water Allocation studies:
During the study period, the water availability after deducting the whole water requirement (Human+Cattle+Crops) in both the watersheds still remained in plenty, which could have been served for many other purposes. The status of the water availability in both the watersheds were more in kharif season as compared to the Rabi season. Hence, planning should be more in kharif crops to utilize the available water.
* Water availability from the surface and groundwater sources:
The average annual water available in both the Awang khujairok and the Waikhulok watersheds are 1150mm and 1300mm respectively.
* Classification of Agro-ecological zones: 
Micro watersheds fall under the agro climatic zone as sub-humid.
* Bio-physical indicators:
During the study period, the biophysical measures, which are being taken up yet, are not able to come up with a reliable conclusion due to the weakness of the soil and water conservation measures with regards to the monitoring and evaluation. So, monitoring indicators is becoming an important task from the evaluation side and for the adoption of the technologies. Some of the biophysical indicators, which are observed during the study period for the effective of monitoring, are mentioned below: -
1. Total population
2. Rate of population increase
3. Status of education system
4. Literacy rate
5. Rural employment
6. Crop yield
7. Cropping pattern
8. Static water level
9. Sources of irrigation
10. Landuse pattern
11. Changes in irrigation area
12. Water availability
13. Drinking water problem
14. Quality of water
15. Density of peoples migration
16. Changes in socio-economic activities
17. Status of technological awareness among peoples
18. Tree density
19. Number of new varieties of trees
20. Soil erosion due to environmental factors
21. Hydro meteorological aspects
22. Adoption of technology
* Area and peak flood relationship:
For Waikhulok catchment, Ryve’s formula gives the lowest discharge. So, we adopt Ryve’s formula for the realistic discharge estimate instead of Dicken’s relationship, which give larger discharge estimate.
Regarding Awang Khujaiork, after consulting some local hydrologist and lecturer in the Government College of Technology, Imphal, they has suggested to adopt the same formula i.e. Ryve’s equation for Awang Khujairok too. This conclusion is base on the following comments from local experts.
1. Waikhulok and Awang khujairok watersheds are having both hilly terrains.
2. Similarly in the river bed conditions i.e. presence of stones and pebbles in the riverbed in all the cases.
3. Slope for all the two cases of Waikhulok and Awang Khujairok watersheds are very close to each other.
4. Lastly, Ryve’s relation gives the lowest discharge estimate compare to other relationship.
* Rainfall Runoff relationship:
In the case of Awang Khujairok watershed rainfall runoff relationship is parabolic in nature. 
That is,
Q = 0.536892745 + 9.354632 x10 –3 R + 8.47 x 10 –7 R2
In the case of Waikhu Lok watershed rainfall runoff relationship is linear in nature. 
That is,
Q = 0.282210+ 0.00994R
* GIS layer plan:
Using Map-Info and ERDAS IMAGINE, the thematic maps of the microwatersheds are prepared and brought into GIS Platform for various analysis. Moreover, GIS analysis is also done by using ARC-INFO Software.
* AVSWAT :
The prepared maps of the watersheds are brought into a AVSWAT platform for predicting Various scenarios of the watershed. However, the streamflow of the watersheds was not close to the predicted value by using the SWAT software. There is a possibility of the unaccounted water entering in the watershed,which has not considered in the existing data base.Recently, spings are located in both the watersheds which could have been one of the factor.

Data used:
* The meteorological datas (Temperature, Humidity, Rainfall, Wind speed, and Wind direction) has been monitored by the AWS in both the Awang khujairok and Waikhulok watersheds from the July 2000 onwards.
* The evaporation datas are collected, by using the Evapo-Panmeter, from the July 2000 onwards.
* The sunshine hours are measured by using the sunshine recorder and the ground water level fluctuation is measured by using the peizometer from June 2000 onwards.

Output:
* Flow Duration curve. (Figure 2)
* Rainfall curve: (Figure 3)
* Unit hydrograph: (Figure 4)

Date of the project completion:
March' 2001

Project Investigator:
Dr. Arun Kumar
Dept. of Earth Sciences, Manipur university,
Canchipur,Manipur. Pin-795003.
E-mail: arunim1[at]sancharnet[dot]in
Phone: 91-0385-2435173