Use of Geographic Information System (GIS) tool in watershed hydrology and irrigation water manageme
Use of Geographic Information System (GIS) tool in watershed hydrology and irrigation water management
J. G. Krishnayya Angira Baruah
MicroTechnologies (I) Ltd, Pune 411037
GeoConcept@vsnl.com
J. G. Krishnayya Angira Baruah
MicroTechnologies (I) Ltd, Pune 411037
GeoConcept@vsnl.com
Introduction
Micro-watershed planning has been conceived and adopted for holistic development of rainfed farming in recent years. Watershed Management is fast becoming a blue print for agricultural development in most parts of the country today. This programme aims at conserving soil and moisture, as well as to put the lands to use according to their capabilities to improve the overall productivity of the catchment. The major objective of the programme is to increase/stabilise production of crops, forage, fruits, fuel and timber in rainfed areas by introduction of improved soil and moisture conservation measures, better crop and rangeland management practices, animal husbandry and afforestation.
The ultimate goal of watershed management is to achieve and maintain a balance between resources development to increase the welfare of the population -- and resource conservation to safeguard resources for future exploitation and to maintain ecological diversity - both for ethical reasons and as an assumed prerequisite for the survival of mankind.
Watersheds
Watershed is an area which catches the water from precipitation and then is drained by a river and its tributaries. It is a "resource region" where the eco-system is closely interconnected around a basic resource - water. The watershed or river basin is therefore an ideal management unit.
A micro-watershed, as defined by Bali in 1978, ranges in between 1-10 sq km or 100-1000 hectares.
The conservation measures and treatments would vary from watershed to watershed depending upon their characteristics, e.g. geographical locations, climatic conditions, soil types etc. Generally speaking, water, soil and biomass are considered to be the three most important components in a watershed. Conservation and regeneration of these resources would call for the need to concentrate on the following aspects :
Micro-watershed planning has been conceived and adopted for holistic development of rainfed farming in recent years. Watershed Management is fast becoming a blue print for agricultural development in most parts of the country today. This programme aims at conserving soil and moisture, as well as to put the lands to use according to their capabilities to improve the overall productivity of the catchment. The major objective of the programme is to increase/stabilise production of crops, forage, fruits, fuel and timber in rainfed areas by introduction of improved soil and moisture conservation measures, better crop and rangeland management practices, animal husbandry and afforestation.
The ultimate goal of watershed management is to achieve and maintain a balance between resources development to increase the welfare of the population -- and resource conservation to safeguard resources for future exploitation and to maintain ecological diversity - both for ethical reasons and as an assumed prerequisite for the survival of mankind.
Watersheds
Watershed is an area which catches the water from precipitation and then is drained by a river and its tributaries. It is a "resource region" where the eco-system is closely interconnected around a basic resource - water. The watershed or river basin is therefore an ideal management unit.
A micro-watershed, as defined by Bali in 1978, ranges in between 1-10 sq km or 100-1000 hectares.
The conservation measures and treatments would vary from watershed to watershed depending upon their characteristics, e.g. geographical locations, climatic conditions, soil types etc. Generally speaking, water, soil and biomass are considered to be the three most important components in a watershed. Conservation and regeneration of these resources would call for the need to concentrate on the following aspects :
- Water resource development: The need for water resource development arises in an attempt to mitigate droughts, moderate floods and harvest the run-off water which otherwise goes as waste. The development of water resources mainly include water conservation techniques. This involves increasing the recharge from precipitation with the creation of sub-surface and surface storages which are capable of impounding maximum monsoon rainfall. Storing of harvested run-off water can be accomplished with the help of various water conservation techniques like the construction of masonry weirs, excavation tanks, composite dams etc. This conserved water can be recycled and used at critical stages of crop growth through lifts, open dug wells, borewells etc.
- Soil Conservation: Soil conservation is by itself the proper land husbandry, which would preserve the land and its fertility on a sustained basis and at the same time increase yields and achieve maximum benefits from such land. Soil erosion is one major problem in the hilly and undulating terrain resulting in low productivity of agricultural land. In order to check this hazard of soil erosion, various conservation measures can be undertaken ranging from narrow based terracing (contour bunding) to bench terracing which would simultaneously include moisture conservation.
- Development of wastelands: Lands that have one or more limitations of slope, erosion, stoniness, rockiness, shallow soils, wetness, flooding, dry climate etc. make them generally unsuitable for the cultivation of agricultural crops and limit their use largely to pasture, forest, wildlife and recreation. These lands commonly known as "Wastelands" are the source of maximum sedimentation, run-off and floods.
The denuded forest lands and wastelands are in fact "Wastedlands" as they have a great potential for producing fodder, fuel, fibre, minor fruits and low quality timber. To achieve this, it is necessary to adopt suitable soil and water conservation engineering measures supplemented with proper afforestation techniques, horticultural practices, grassland development etc.
- Conservation and development of Forests/Vegetation: Vegetation (perennial or annual trees, or shrubs, climbers or grasses) on the site is one of the factors that govern the run-off water which affects erosion. Vegetative control can be one of the essential anti-erosion measures, since it is under human control, unlike rainfall.
Forests, in general, bring about a long chain of advantages: moderating the local climate, preventing floods, regulating stream flow, sustaining off-season discharge, protecting the soil and enriching it. Thus, an organised maintenance of all perennial vegetation on site is called for.
- Animal Husbandry/Livestock Management: This would include the population characteristics, type, numbers, quality, distribution, feeding habits etc. of animals as well as birds and marine life. Activities concerning the improvement of livestock management includes pasture and fodder development, improvement of grazing land, stalk feeding and fodder supplies, reduction of grazing pressure on land, improved milk production, other livestock development like sheep, goats, poultry, fisheries, development of small scale/cottage industries for milk products etc.
- Human Resource Development: Since the ultimate aim of the Watershed Development Programme is to improve the quality of life of the local people, human resource development is one of the most important aspects to be taken care of. It can be approached through awareness and training programmes.
Data regarding population characteristics, professions, socio-economic conditions, land ownership, tenure, employment status, outside jobs etc. are required for any kind of undertaking in this sector.
+ نوشته شده در 2008/5/9 ساعت 17:15 توسط محمد ملکشاهی
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