In recent yesteryear, the impact of drouth doing to H2O and nutrient deficits and devastation of ecological system had been widespread and became a national concern. Turning concerns over a possible addition in the frequence and badness of drouth, along with the mounting grounds of the spread outing exposure to drought, underscoring the importance of effectual direction of information is being progressively recognized in the drouth catastrophe direction. The success of drought catastrophe direction mostly depends on handiness, airing and effectual usage of information. The information needs include meteoric parametric quantities like rainfall, wind velocity and way, humidness, temperature and dirt conditions etc. to measure drought conditions. The paper chiefly focuses on the present scenario of drought direction utilizing GIS and it besides discusses the hereafter trends that arise with the rapid developments in different technological foreparts for efficient catastrophe direction.
Drought is a natural catastrophe that differs from other catastrophes as it has a slow oncoming, evolves over months or even old ages and affects little pockets to a big regional sweep following lacks in rainfall or its fickle temporal and spacial distribution. The drouth is manifested in footings of harvest failure and depletion in surface and groundwater resources. The effect is large-scale human migration and loss of farm animal and human lives due to scarceness of H2O, nutrient, provender and fresh fish. Droughts in the beginning of the season adversely affect the seeded country go forthing big parts of agricultural lands as fallow. Mid season drouths result in hapless harvest growing and decrease in harvest outputs. Decrease in income and buying power of husbandmans turns the little and fringy husbandmans into agricultural laborers taking to increase in unemployment.
Types of Drought
The National Commission on Agriculture in India classified three types of drouth: meteoric, agricultural and hydrological. Meteorologic drouth is defined as a state of affairs when there is important lessening from normal precipitation over an country ( i.e. more than 10 % ) . Hydrological drouth consequences from drawn-out meteoric drouth ensuing in depletion of surface and sub-surface H2O resources. Agricultural drouth is a state of affairs when dirt wet and rainfall are unequal to back up healthy harvest growing.
Drought Scenario in India
About two tierces of the geographic country of India receives low rainfall ( less than 1000 millimeter ) , which is besides characterized by uneven and fickle distributions. Out of net seeded country of 140 million hectares about 68 % is reported to be vulnerable to drought conditions and about 50 % of such vulnerable country is classified as aa‚¬E?severeaa‚¬a„? , where frequence of drouth is about regular.The 2002 drouth had reduced the seeded country to 112 million hectares from 124 million hectares and the nutrient grain production to 174 million dozenss from 212 million dozenss. The entire nutrient grain production in India has to be stepped up from 212 million metric dozenss to 300 million metric dozenss by 2020 to run into the nutrient demands of turning population. Therefore, there is a demand for effectual monitoring of agricultural drouth, its oncoming, patterned advance and impact on harvests to minimise the amendss.
Drought Management Cycle
Drought direction refers to the comprehensive scheme in all stages of catastrophe to optimise efficiency of planning, response and efficaciously cut downing the impact of drouth. Drought direction rhythm consists of different stages: Preparedness, Mitigation, Response and Recovery.
During preparedness stage of drought direction, the activities designed to increase the degree of preparedness and betterment of operational and institutional capablenesss for reacting to a drouth from the types and impact of drouth. Drought readiness involve designation of drouth prone countries, H2O supply augmentation and preservation ( e.g. rainwater reaping techniques ) , enlargement of irrigation installations, effectual covering with drouth, public consciousness and instruction. Further communicating plays an of import function in roll uping the land informations in existent clip and to circulate the prognosis and warning information with close real-time information on prevalence, badness degree and continuity of drouth.
During extenuation stage of drought direction, the long term and short term steps are implemented for catastrophe extenuation that include actions, plans, policies, preparation, instruction and capacity edifice to cut down the magnitude of hazard to human life, belongings, and productive capacity.
Response stage of drought direction include alleviation and deliverance actions taken as the event takes topographic point. It involves attempts to minimise the jeopardies created by a drouth by pulling an action program to analyse the drouth phenomenon and supply solutions such as relief employment, auxiliary nutritionary programme and relief to the affected people.
Recovery stage of drought direction is critical to reconstruct the farmaa‚¬a„?s productive capacity every bit rapidly as possible in order to retrieve from the impacts of the drouth and to reconstruct to normal conditions. Good rainfall may supply favorable chances to restart cropping, croping and restocking nevertheless it is slow because of long recharge periods for surface and subsurface H2O supplies. The drought recovery and planning include equal grazing land growing to justify croping with decreased auxiliary eating, sufficient dirt wet for grazing land or harvest constitution, equal H2O for stock and domestic usage.
Drought Assessment and Monitoring in India
In India, National Agricultural Drought Assessment and Monitoring System ( NADAMS ) is a distant sending based agricultural monitoring mechanism supplying agricultural drought information in footings of prevalence, badness, and continuity at province, territory and sub-district degree. Monitoring of drouth is restricted to Kharif season ( June-Oct/November ) since this season is agriculturally more of import and rainfall dependant. Agricultural conditions are monitored utilizing daily-observed harsh declaration ( 1.1 kilometer ) NOAA ( National Oceanic and Atmospheric Administration ) satellites AVHRR ( Advanced Very High Resolution Radiometer ) information, Moderate declaration informations from Advanced Wide Field Sensor ( AWiFS ) onboard Resourcesat 1 ( IRS P6 ) of 56m, Wide Field Sensor ( WiFS ) of IRS 1C 1 D of 188m and temporal revisit period of 5 yearss are being used for elaborate appraisal of agricultural drouth at district/sub-district degree ( V. Bhanumurthy 2008 ) . The comparative divergence of Normalized Difference Vegetation Index ( NDVI ) from that of normal and the rate of patterned advance of NDVI during the season give the indicant about the agricultural state of affairs in the territory which is so complemented by land state of affairs as apparent from rainfall and seeded country. The methodological analysis being adopted in NADAMS basically reflects the integrating of orbiter derived harvest status with land collected rainfall and harvest country patterned advance to germinate determination regulations on the prevalence, strength and continuity of agricultural drought state of affairs. The agricultural drouth information therefore derived is being provided to the user community in the signifier of monthly studies. The NADAMS study is utile for the determination shapers for the direction of agricultural drouth at province, territory and sub-district degree supplying a comprehensive image of the drouth state of affairs which acts as complimentary information along with their land based information.
Integrated Drought Assessment in India
Unified index for drouth badness appraisal by incorporating the information from different beginnings has initiated to heighten the range of drought appraisal. To do the standards unvarying irrespective of part or province, Standardized Precipitation Index ( SPI ) is used to measure the lack of rainfall, since it has been standardized with average nothing and discrepancy one. The impact of rainfall can be measured in footings of dirt wet handiness through Soil Moisture Index ( SMI ) , retrievable through H2O balance processs ( V. Bhanumurthy 2008 ) . This index allows integrating variableness of dirt parametric quantities, harvests and conditions, which lead to better appraisal of drouth over the turning season.
Automatic Weather Stations in India
ISRO has taken inaugural to set up Automatic Weather Stations ( AWS ) through out the state in a phased mode for aggregation of precise conditions informations at local degree and transmittal on existent clip footing for resource direction every bit good as for bettering presently available conditions services ( P.S. Roy 2008 ) . AWS records informations on the meteoric parametric quantities like rainfall, wind velocity and way, humidness, temperature etc. Particular detectors of peculiar involvement can besides be included in AWS, to mensurate dirt temperature, foliage wetness, etc. The AWS informations discoveries extended applications in agricultural monitoringaa‚¬ ” drought/crop status appraisal, harvest direction.
There is a demand to get at a scientifically true step cutting across assorted rainfall zones and socio economically acceptable index of drouth for the state. Procedures have to be developed for early drouth sensing and measuring the quantitative impact of drouth on agricultural production through the usage of orbiter informations and assimilation of informations from land sections, routinely collected by assorted agricultural related sections of the state. An incorporate Decision Support System ( DSS ) and web-based GIS needs to be developed with appropriate weightages to the informations obtained from AWS such as rainfall, dirt wet and harvest status etc. , for effectual usage of the land observations and informations in concurrence with infinite informations, to deduce updated information on catastrophe events and supply determination support
Drought conditions are characterized by land observations of rainfall, harvest status, dirt wet etc. Automatic Weather Station ( AWS ) plays a polar function to acquire elaborate conditions information in the country of involvement. Decision Support System ( DSS ) An integrated DSS and Web-based GIS has the advantage for the monitoring and direction of the drouth using the capablenesss of distant feeling informations, geographical information system and cognition based systems therefore facilitates to enable analysis, show and acquisition of informations utilizing the cyberspace.