TINJAUAN PENURUNAN MUKA AIR TANAH AKIBAT PEMANFAATAN UNTUK IRIGASI DI DAERAH JOGONALAN-KLATEN JAWA TENGAH

• Main Author: Sudarto (NIM 22195049), Lanjar
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/4699
• Institution: Institut Teknologi Bandung

<br></i> Abstract :</b><i><p align=\"jutify\"> <br /> The study was carried out in ricefield development area located in Jogonalan, Klaten, Central Java Province. It is section area of Dengkeng River cathment areas. Topographically, this area is relatively flat (0-3%), with agroclimatic type C2 (5-6 wet mounth and 2.3-4 dry mounth per years). Total precipitation for the mounth with highest rainfall in January (360.1mm) and the lowest in August (16.8mm). The average annual precipitation was 2300mm. <br /> <p align=\"justify\"> <br /> The physiographic area study were dominated by Merapi-Merbabu plain. The geology in this area consists of young Merapi vulcanic materials products (sand, tuff, breccia and pumicce). The unit sand and tuff Merapi and unit vulcanic Merapi were Quartenary age underlaying the tertiery formation Upper Kalibeng. There has two-layered aquifer systems; an upper unconfined aquifer by the unit sand and tuff Merapi, and lower confined aquifer by the unit vulcanic Merapi. <br /> <p align=\"justify\"> <br /> Base on intrepretation of pumping test data have caracteristic akuifers are thickness aquifer 57-75m, transmissivity 97.2-456.7m²/day, storativity 6.789-1.361 x 10^-3 . In implementation of groundwater pumping with 23 wells for irrigation on 604 Ha areas during wet season (October 1995) to dry season (April 1997) would cause water levels drawdown about 2.05-7.88m decrease. <br /> <p align=\"justify\"> <br /> The result on analyses for hidrogeolcgical parameters by simulation model indicated that aktua! pumping rate discharges greater than recommanded maximum discharge, abaut 6 percent. For this reason to reducing drawdown water levels must reduce the aktual pumping rates, abaut 25 percent. The water requirement for irrigation this areas will be complete if the ajusting initial cropping date.