水文・水資源学会誌 第30巻 第4号（2017）

Hydrological Research Letters第11巻 第1-2号 目次と要旨
http://www.jstage.jst.go.jp/browse/hrl
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Golam Saleh Ahmed Salem, So Kazama, Shamsuddin Shahid, Nepal C. Dey
Impact of temperature changes on groundwater levels and irrigation costs in a groundwaterdependent agricultural region in Northwest Bangladesh
85-91
Abstract: Changes in hydrological processes due to rising temperatures and related effects on the socio-economy
and people’s livelihood are major concerns in Bangladesh. A study has been performed to assess theeffects of increasing temperature on the groundwater levels and consequent changes in irrigation costs
for groundwater-dependent irrigated agriculture in Northwest Bangladesh. A support vector machine(SVM) was used to model the temporal variations in groundwater level from rainfall, evapotranspiration,groundwater abstraction, and agricultural return flow. A multiple linear regression (MLR) model wasdeveloped to define the functional relationship between irrigation costs and groundwater levels. The
model showed that average groundwater level during the major irrigation period (January-April)decreased by 0.15-2.01 m due to an increase in temperature of 1-5°C, which increased irrigation costs by0.05-0.54 thousand Bangladesh Taka (BDT) per hector.

 alda A. Belgaman, Kimpei Ichiyanagi, Rusmawan Suwarman, Masahiro Tanoue, Edvin Aldrian,
HArika I. D. Utami, Sheila D. A. Kusumaningtyas
Characteristics of seasonal precipitation isotope variability in Indonesia
92-98
Abstract: The few previous studies of precipitation isotopes (δ18O and δD) in Indonesia, based on low spatial
resolution observation datasets, have found several types of patterns in their seasonal variabilities. Thisstudy conducted high spatial resolution rainfall sampling and investigated the temporal characteristics ofprecipitation isotope in Indonesia. Rainfall samples were collected weekly from 33 stations in Indonesia.
Cluster analysis showed that Indonesia could be divided into four types based on the seasonal variabilityof the precipitation of δ18O. The majority of stations showed seasonal patterns in the variability of δ18O,characterized by high values in the dry season (July-October) as type 1. Type 2 also showed one peak ofhigh δ18O but in the longer period (June-November) was similar to type 1 stations. A region of Northwest
Indonesia, comprising North and Central Sumatra and western Borneo, was identified as type 3, having
two peaks of high δ18O values in January-February and May-August. Another pattern of variability was
the anti-monsoonal type, indicated by low δ18O in May-July found in east part of Indonesia. AsiaAustralia monsoon regime was the main factor that controls seasonal δ18O variability. This researchshowed that stable isotope in precipitation could correspond to precipitation climatology in Indonesia.

Idham Riyando Moe, Shuichi Kure, Nurul Fajar Januriyadi, Mohammad Farid, Keiko Udo, SoKazama, Shunichi Koshimura
Future projection of flood inundation considering land-use changes and land subsidence in会告189

J. Japan Soc. Hydrol. and Water Resour.Vol. 30, No.4, 2017

Jakarta, Indonesia

99-105

Abstract: Jakarta is facing several issues related to flooding, including land subsidence in the coastal area andrapid land-use/cover changes in the upstream area. In this study, we analyzed the effects of futurechanges in land use and land subsidence using a rainfall-runoff and flood inundation model. The futureland-use scenarios were projected based on the SLEUTH model, and land subsidence was projectedbased on an extrapolation of the current state in Jakarta.
Based on this analysis, land-use changes and land subsidence contributed to an increase in floodinundation volume of 36.8% from 2013 to 2050. Moreover, the effects of land-use changes on floodinundation in Jakarta were much greater than those of land subsidence. The government s current target
to stop land subsidence by 2020 would cause a 7.7% decrease in the flood inundation volume by 2050.
Furthermore, controlling and regulating land-use/cover changes by 2020 would cause a 10.9% decreasein the flood inundation volume by 2050. From these results, we conclude that a flood mitigation planshould be made not only for land subsidence, but also for land-use changes.

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