Changes in Water Resources Systems: Methodologies
to Maintain Water Security and Ensure Integrated Management (Proceedings of Symposium
HS3006 at IUGG2007, Perugia, July 2007).
IAHS Publ. 315, 2007, 56-61
Externalities
in watershed management
PRADEEP P. Lodha1 & ASHVin K. Gosain2
1 Civil Engineering Department, L. D. College of Engineering, Ahmedabad 380015, Gujarat, India
2 Civil Engineering Department, Indian Institute of Technology Delhi, New Delhi 110016, India
Abstract The term “externality” is used to describe the indirect or accidental consequences of actions associated with watershed activities. Building new structures, afforestation and soil/land treatments are a few such watershed activities. The present paper demonstrates the measurement of externalities in an experimental watershed through GIS-based watershed modelling and using livelihood indices. The simulated results show that the surface runoff has reduced by 11.22% and 22.56% for the 2007 and 2012 futuristic forest policy scenarios, respectively. Heavy losses in surface runoff may reduce the water availability to downstream areas, stressing water demands, especially during the water stressed months. This has also been reported in the primary survey conducted during 2004. An analysis shows that for a downstream village, Amoli, the average time spent in water collection for domestic uses has increased by about 4%. The experimental micro-watershed Dudhi is located in the Raisen district of Madhya Pradesh State, India.
Key
words externalities;
forest policy; GIS; India; watershed management; watershed modeling