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GEOMATICS 23-01-2021
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LAN
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drought
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File: spi.php
<?php include ("session.php"); include("header.php"); ?> <title>Drought Management Support System</title> </head> <form action="spi.php?name=<?php echo $var ?>" method="post" > <body> <table style="text-align: left; width: 98%; height: 10%; margin-left: auto; margin-right: auto;" border="0" cellpadding="0" cellspacing="0"> <tr> <td background="image/back1.jpg"><table width="99%" border="0"> <tr> <td valign="top"><table width="98%" border="0"> <tr> <td><p align="justify"><span class="style3"><strong>Standardized Precipitation Index (SPI)</strong></span></p> <p align="justify"> <br /> The SPI (Standardized Precipitation Index) has been used to quantify the deficit of precipitation. It can be computed at different time scales from less than 1 month to 48 months or more. The calculation time period depends on the user’s application. Short-term SPI can be used to detect agricultural drought, and long-term SPI can be used for water supply management. </p> <p align="justify"><br> SPI is the ratio of the difference between individual rainfall values from the historical mean value and the standard deviation for the station, for the time scale. The SPI value normally ranges from -2 to +2.</p></td> <td width="40%" valign="top"><br><br><br><br><div align="right"><img src="image/SPI.jpg" alt="" width="400" height="300" align="top"></div></td> </tr> </table> <p align="justify"> SPI has several advantages over other drought indices. The first one is its simplicity. SPI is based only on rainfall data and requires only the computation of two parameters. Second advantage arises from its variable time scale, which makes it useful to describe drought conditions in meteorological, agricultural and hydrological applications. Temporal changeability makes it possible to determine drought dynamics, such as drought onset, duration and end. Third advantage comes from its standardization, which ensures that the frequency of extreme drought events at any location and any time scale are consistent. So in our work we are using SPI. </p> <p align="justify">Meteorological data pertaining to daily rainfall has been collected for a period of 111 years ranging from 1900 -2011. Weekly rainfall for 82 rain stations will be used to analyse relations between NDVI and rainfall and also to derive Standardized Precipitation Index (SPI). The data has been collected from Indian meteorological center, and other Organization. Therefore to maintain consistency </p></td> </tr> </table></td> </tr> </table> </body> </html> <?php include("footer.php"); ?>