Land Use Changes and Forest Degradation in a Himalayan Watershed: Analysis and Policy Alternatives

摘要

Agriculture, horticulture, and forestry are the mainstays of the economy of the Indian state of Himachal Pradesh. The economic, technological, and institutional factors that affect land use need to be analyzed in a holistic way, especially in view of fast changing cropping patterns and declining forest density. The use of a bio-economic programming model incorporating economic and ecological factors appears to be a highly attractive tool for analysis at a micro watershed scale. The objective function of the model is to maximize the discounted gross margins from different sets of activities, namely, agricultural, livestock, and forestry over a 20 year model horizon. The model becomes non-linear by incorporating a variance and co-variance matrix of gross returns over the last five years. The model investigates the effects of alternate policy scenarios on income levels, cropping patterns, biomass use and its growth, and labour and capital requirements over next 20 years by using the General Algebraic Modelling Systems (GAMS). The biomass growth is based on a logistic growth model. Though there is a sharp increase in income by replacing traditional crops with horticultural crops, such changes are also accompanied with increased income risk. Results show a diversification strategy on the part of farmers in the study watershed rather than only maximizing profits. The biomass growth becomes sustainable if there is an increase in emigration rate, use of liquefied petroleum gas (LPG), and substitution of improved livestock. More such response through government policies can improve long term sustainability.