Monitoring of Water Utilization and Water Balance on Agriculture Fields in Nganjuk, East Java, Indonesia

ISSN 1881-4948

APPLIED HYDROLOGY

NO.23

2011

iF

3

ｾ

､ｂｾ､ｂｩ､ｉｾＮｯＮ

ｾ

ｾ

ｾ

Ｇｲｾ

ｾ

ZJ;

Applied Hydrology

No.23

ｾＮｧＮＬｲＬＷ ;I

:.-''1:-7

Iva-

.l'lh

,t:-

<I

iiIi!,je 'l\fj'tO):fif*'rilllJ

,. '"

··1

ｾｾＪｾＪｾｾｾｾｾｾ

ｾｾｾｾ

7I<#Ij!jj1!j ｭｾ

<I,

ｍＡＺｮｾＺｬＺｏＩｩｬｾ

'ill

Ji'!.i:jSj-fF4io704' -

ｾ ;llvjfａｏＩｾＣｉｉＦＱｻ｝ＨＧ［ＺＺＱＯｉＮＱＺｲｔｬ＾ＮＢＢＢＢＢＢＢＢﾷ

11

ＮｍＪｾｾｾＮ ＸｭＮﾱﾷＮｾ ＮﾷｾｭｾＮ

Krissandi Wijaya .

,\II;

m!J..t£

ｊＱ［［ｾｍｭＡＡＺＡｊｪｕｉ［Ｌｪ･ｦｬ｝ＪｾｏＩｩｬｊａｩｬｬｩｐｔｊｬｬｩｩｬｅＺｬＺｉ［ＺＺＴ［ｴ

0 J&91;::

Ｐｾ

'c

21

..

ＱｩｊｦｩＡ｜ｬｴｬＴＺｨＮｦｦｬｬＧＡＧｬＧｉｉＡｾｊＡｉｏｉｩｊｦｾＭ･ＺＮＭＧ＿ＧＭ ＡｊＮＮｬＪｭｾＱｘｍﾷＮｬＱＬｬｬ｜ＺＡｊＳ

fJl!&O)iTJ;l!?' A

ll!:illl:ill

;;::t

70

OO-j- A?' A?, AO)ftT,jeIth'Wl'lIH;::4;t ol>'I!'rill

l] 31

ｾＱｩｊｦｩＡ｜ｬｭｾｾｉｾｾｭ ｉｾｾｦｵＧｾＪｾｾ

ｩｬｩｬｊｉｉｾ＾｜ｬｃＮ

. 8mll\:M

ｩｩｬｅｾｏＩＬｪ･ｾｩｬｩｬ｜ＮｩｬＧ

6

ｊｬＮｴＺＺＡ＾ｬｭｦｦｬＬｪ･ＺｩｬＺｏＩｾﾥｻ､ｪｪ ···41

ｾｾｸＺＮＭＧｹｹＷｹＺＮＭＧ＿Ｇｾｾｾｾ ｾ ｾＡｊＳﾷｌｾｭﾱ

OO±I'l'!;:::l

:.-'''tlv?,Ｏｙｾｾｾｴﾱ

JEft'l5z

ｾｾｾｦｴＪｾｾｾｾｾＮ ｾｾｾＤ

ＭｾｩﾥｊｴｴｦｬｾＺｬｈｾｉｩｊｉＺｍｴｭｾｏＩｬＪＡＦｏＩｦｬｾｪＧｴ 51

ｾｗｾＪｾｾｾＮ

ｾＣＪｚﾷｾｾＪｾ

ｩｩｬｅｾＬｪ･

'i{ilil\

ｾｊＱｬ｛ 0)

t:-

It>

0)

ll1',je lI!!i1I!ffl

'l:-71v

58

ｾＱｩｊｦｩＡ｜ｬｉ｜ｙｩＯｬｗｉｾｾｭ ｩｬｩｬｊｉｉｾ＾｜ｬｃＮ

.

ｉｾＮｦｵ

Ｘｭｬｬ｜ＺｍﾷｾＪｾｾ

mM£?'

ａｏＩｾｾｊｊｬｅｏＩｴｾｉｴ＾ｏＩｾＬｪ･ｉｬｊｩｬｩ｛ｾｷｲｾＤｏＩｦｊＡｉｾ

·.. ·

·.. ·

·.. ·.. ·..

·67

ｩｔｾＪｾＪｾｾﾧｾｾｾｉｩｊｦｾｾ ｾｾ ｾ

ｩｔｾＪｾｾｩＡｈｩｊｬｬＡＣｾＭ･Ｏ＿ＧＭ

8JIIJ:m· <j;:mli5l*

ｩｔｾＪｾＪＤＺｾﾧｾｾｾｾｾ ｉｎＡＺｬｾﾥ

ｩｔｾＪＤＺｾｾＮ ｾｾｾＭ

Monitoring of Water Utilization and Water Balance on Agriculture Fields

in

ｎｧ｡ｮｪｾ

East Java, Indonesia

(4' /

r

-*

ｾＷＬ

'"

1"

9 .l1,-j-:.-' '" "- /'

:7

±t!lllXl::::J3It 0 .l!J!IOlt!l1l\'O),jeflJffl I:: ,je1{](xO)llllI3!t)

76

ｊＱｴＩｪ［［ｾｉＪＤＺＪｾｾｩＱｉＡＮｧＮｾｾｉｩｊｦｾＣ Liyantono

ＮｍＪＤＺｾＤＺＮ Ｎｾ ｾﾷＬ｜ｉｉ［ｭＡｊＮＮＤﾷＸｭＮﾱ

ltmJkxNo.n 2011 r:..-:.--.r.V?ａＴｩｕＮｾＮｊ

Applied Hydrology

Monitoring of Water Utilization and Water Balance on Agriculture Fields

in

Nganjuk, East Java, Indonesia

ｾｾｾＪｾＷＮ

ｾｾ＿ｾｾｾｾｾｾ

• •

ｾｾｾｾ

• • •

ＪｾＪｾｦｦｬｾ

ＪＡＦｾｾｾｾ

Liyantono·, Tasuku

KArn··,

Hisao KURODA··, Koshi YOSHIDA··

• United Graduate School ofAgricultural Science, Tokyo University ofAgriculture and Technology (3-21-1, Chuuo,

Ami, lnashiki,lbaraki. 300-0393).

"Faculty ofAgriculture, Ibaraki University <3-21-1, Chuuo,Ami,lnashiki,lbaraki, 300(0393)

Liyantono' •

!JuHi1li"

,

ｩＡ｜ｾｒＤＢ ,｡ｾｪｬｻﾱＢ

'JI(:;;;:.!lI:k;;Ci!!il'Ｎｾ＿ｏＺｈ (T 300-0393 ｾｬ｝ｪＨＡｉｩ｜ｬｩＱｩｬｬｬＺｬｬＱｉｬ｜ｩｊＮｬｖＮｔＧＡＧＬＪ］ 3-21-1)

Ｂｾｬ｝ｪＨＺｫ［［ｃＮ［［｣ｬｬ｜ｬ (T 300-0393 ｾｬ｝ｪＨＡｉｩ｜ｬｩＱｩｬｬｬＺｬｬＱｉｬ｜ｩｊ .l!.1IIT'!'

'*=

3-21-1)

Abstract

In the dry season, water shortage has occurredinNganjuk, East Java, Indonesia. The northern area of Nganjuk irrigation blocks was drier than southern area, and downstream in southern area was drier than upstream area. Regardless the water shortage, the farmers of these areas would like to increase productivity, cropping intensity and fanner's income by using shallow and deep wells.Inthe future,the utilization of groundwater for irrigation canbe

impact to land subsidence and can compete with other uses of groundwater such as domestic and industrial. The estimation of groundwater uses for irrigation is required for sustainable water resource management and farmers prosperities.

Monitoring stations were installed in Nganjuk to analyze water balances. Shallow grOlmdwater levels were monitored at four irrigation blocks. The discharge rates were monitored in river reaches of upper. middle and lower streams. The monitoringdataof groundwater showed the tendency of recharge in rainy season and uptake indryseason. However, in southern area Mrican-Kiri block, the tendency was not clear. Groundwater levelsinthe southern area (Mrican-Kiri and Kuncir-Bodor blocks) were higher than those in nonhern area (Widas and Ketandan·Tretes blocks)in

dryseason. The rainfaU and discharge ratedatashowed that the infiltration and percolation were high in the beginning rainy season. Base flows were increasedinsecond month of the rainy season andpeakdischarge was around 6 nun d-I

in the upper stream and approximately 2 mm d-linwhole watershed.

Key words: groundwater. water shortage, conjunctive irrigation, monitoring

Jf

ｾ

.{ ;,.- l'

-*

V7. ｾＱＢ ｲｹＢＷＧ［ＢＭｾ ｾ

"P

jjBllIGl::Jov''(, ｩｊｴｾｉＺＺＷｉ＼ＧｆＩｅｬｬＧｾＡｅ l.-'(v'Qo ＷＧ［ＢＭｾ ｾ

"P

Q)!iillt 7' p "

P

I::Jov ,'( I;l:, jtll\l7' p "

P

lllitillll7' p "

P

J::ｾ 7I<'F)Ell

1

0

1:'

<,

ll: t::itill\l7' p "

P

I::Jov ,'( t Tilft l]j('t'I;Ll::ilftlllGJ::ｾ 7I<'FJEll1₀

i:''''Ii(il/.

_{'t'",Qo 7I<'FJEI:: t Il!lb I',}

-r.

_{ｾｨ I',Q)7'p "}

P

_{I::Jov ,'( ,ＧＱＧＡＭＮＡｬｾｉ［ｬＺ}

jjBT7I<Q)!&;7;-J:Ii'I:: J:: ｾ ＺＧｅｩＱｬ＼ｩＧｉ［ｾＬ 1'F#IID'lii:, ＮＡｬｾｩＦｊ＾ＬＮ ｾｴｴｬＡｊｏ l.- J::

?

I:

;;1:;7;-

'(v'

Qo

¥-l-*,

ｾ Q)J::

?

tti'llillt

Q)t::!I:>Q)jjBT7I<Q);f1JJll!;l:, jjBti:ltTJ(>. ｩｉＡｬｩＱｬ＼ｾｾＡｅｦＰＵｊＧＡＱＷＱ＼

I:

ｑＩｦｴｩｬＧｾＵＱ ｾ ｩｩＡｬｾ T ｾ

I:

ｬｬＧＡＡｬＱｩｾ

2=hQo

't

ｾ 't', jjBT 71< Q)iliiMJ'!I ifil::lllIl.- '(, j,Wlfiifllli tt7l<iiiJl(1'l!\!

I:

ＮｾｉＺＺＨｏｪ It7l<i&:>:ｾ Jlt!l:>Q_o

't

ｾ 't', 7I<i&:>:Q)t::!I:>'l';?"ｾ ;,.-!/;<

'T-V

3 ;,.-H!j;J>,. l.-fto i'lIillt7' P'Y

P

ｾ 4ＭＺ＾ＱＺＺｾｬｴＬ i<l<lIIjjBT7I<Q)

jjBT7I<ilLHUlIl.-t::o fiiJ)III::Jo,''(t, J:, ,!" Tilftl::'('l';?"ｾ ;,.-!/H1"', ｩｬｦｴＺ｡ｾｊｬｴＡｬＺ＾ｴＺＺｯ jjBT7I<Q)'T -?" ll' 1',. ｭｾｉＺＺｊｯＬ ''(It!!T7I<1l'iIfi*

2= h,

ｩｊｴｾｉＺＺｊｯｶ ＧＬＨＡＦ［Ｗ［ＭｊＺＱｩＧＱｬＧＺｫｾ

<

tt

Q

ｾ

I:

ll'iF

2=

ht::

o l.-ll'l.-,

itill\l7'P'Y

P

<7) A ｾ 71"

;"-'1"

ｾ 7'P "

P

't'1;l:. 1jIj11M:f§l(Ojll'lt I',h

-r,

ｩｊｴｾｉＺＺｊｯｶ ,'( I;l:, itill\l7' P'Y

P

<7)jjB

T7I<ilLl;l:jtll\l7'p "

P

J::ｾ ;lIj

<

tt"?fto

*-

ft, ｾｭ

I:

fiiJJII ilftJt'T- ?" ll-I'" ｭｾｑＩｍＱｬｬＺ Qm'fjt)jl::llI:*=:all'ttl

1. INTRODUCTION

Grain productionindry season is still important for regional sustainable development in Indonesia. Java is

the main production area forgraininIndonesia, where 53 percent of paddy and 55 percent of com from each total

production are produced (BPS, 2009). Agriculture in Jav.a mustbe conserved for sustainable food security in

Indonesia. For that purpose. improvements in land use and water management are needed.

The Nganjuk lies in a climatic regime characterizedbythe annual progress of rainy and dry seasons, and

receives approximately 80% of precipitation within the 5 to 6 months of the rainy season (December-May).

Nganjuk has flat area in central and eastern of Nganjuk with altitude raoging from 35 to 100 m ahove sea level.

MOWltainsarelocatedinthe southern and northern area. The agricultural production in Nganjuk was increased;In

1991, average cropping intensity

was

2.31 crops per year (BPS ofNganjuk, 1992), and iD 2001 it

was increased

and stable at 2.8 crops per year. Rice production was 414 metric tonperyear with productivity around 5.8 ton per

hectare and harvested area was71,893 hectare. Com production was 204 metric ton per year with productivity

around 5.8 ton per hectare and harvested area was 35.144 hectare. Soybean production was 17 metric too per year

with productivity arouDd 1.7 IDn per hectare and harvested area

was

10,091 hectare (BPS ofNgaDjuk, 2009).

The Nganjuk lies in Brantas basin at Widas sub-basin. where is one of the threemajor tributaries of the

Brantas River in East Java Province. In Nganjuk, there are three planting season; wet season (WS,

November-February),

first

dry season (OSI, March-June), and secoDd dry season (DS2, July-OCtober). Paddy

fields are cultivated iD WS and OS!. Sugarcane cultivated in WS, DS1, and DS2. Secondary crops (com, soybean,

red onion, chUies, melons and vegetables) are cultivated in DS I and DS2.

Water shortagehasoccurred indry season in all irrigation blocks. The northern area of irrigation block was

drier than southern

area.

The downstream in southern part area was drier than upstream area in dry season.

Regardless of the water shortage, the farmers of these areas would like to increase productivity, cropping intensity

and farmer's income by using shallow and deep wells. The cash crop is important to increase farmer's income.

especially in dry season. These economic situation influences in the water balances. so it is important to analyze

water balancesinthe Nganjuk.

10 the future. the utilization of groundwater for irrigation can beimpactto land subsidence and can compete

withother uses of groundwater such as domestic and industrial. The estimation of groundwater uses for irrigation

is required for sustainable water resource management and farmers prosperities.

Anobjectives of this paper is to analyze monitoring data for water balances. For further research. the data could

beto develop a computer simulation model to propose a sustainable water resouce management and to increase

water utilization on agriculture fields.

2. STUDY AREA

The lowland

in

Nganjukisalluvial plain formed hy Widas River aDd Brantas River. Based OD hydrogeDlogy

map (Pnespowardoyo, 1984), these areahasaquifer with medium andhigh productivity. Many irrigation wells

were constructedinNganjuk. The number of wells in village

was

varied from 0 to 606 wells per village and total

number of wells is 15,475 wells on around 200 villages.

-There are four main sub-basins, Widas. Kuncir. BodorandWarujayeng-Kertosono (Hg.l). There are two

tributaries, the Kedungsoko River and the Widas River. the Kedungsoko Riverisfor KuncirandBodor sub-basins,

and the Widas River is for Widas sub-basin. Those rivers were merged into Brantas River through

Warujayeng-Kertosooo sub-basin that is flat and predominatedbyagriculture field.

Inaddition., irrigation area in Nganjuk was divided four irrigation blocks. Thearea of irrigation blocks is

around 40,000 hectare. There are two main surface irrigation systems (Widas and Mrican-Kiri blocks) and two

local surface irrigation systems (Kuncir-Bodor and Ketandan-Tretes blocks). Each blockhascharacteristic depend

on the water supply system and geomorphology (see T.ble 1 and FIg.2). The main surface irrigation system has

infrastructure such as canal, reservoir, and water supply. The local surface irrigation haswatersupply from small

and seasonal rivers. Widas block lies in Widas sub-basin and supplied water from Beoing Reservoir and small

rivers in the block. Mrican-Kiri block is supplied water from Mricao barrage 00 Braotas River and lies in

Warujayeng-Kertosono and Bodor sub-basins. Kuncir-Bodor blockissupplied water from small rivers from Wilis

Mountain without reservoir and liesin Bodor and Kuncirｾ｢｡ｳｩｮｳＮ Ketandan-Tretes block is supplied water

from smaU rivers from Kendeng Mountains with

smaU

reservoirs and lies in Widas sub-basin. All of irrigation

systems in Nganjuk area are conjunction irrigation surface and groundwater irrigation and reusing drainage water

from upstreamarea.

--Rive<

C l - -

bou"""

C

Nganjukdistrict

_35.100

!

_100·200 0200.400

_400-800

E

L.':S=:===:.E::===s=,!--,::_:;:::800:==-'::...

:;:::m:==:=:i::!

ｭｾ tn"!lin:rE: 111"55'11"e IlTOO"E 11Z"'5'II"E ＱｉｴＢＱｾ

79 -3. INVESTIGATION

Based on preliminary field survey. the monitoring data station was developed (Fig.2). Water quantity and

water quality was monitoredinthose stations. The nwnber of station was decided based on cost of construction, maintenance. and security. The shallow groundwater levelwasmonitored at four irrigation blocks. The river water

level was monitored at upper, middle and lower reaches, and observed discharge ratc in those stations.

The shallow groundwater levelwasmonitored at four irrigation blocks. Each irrigation block was installed

one monitoring well. The monitoring well at Ketandan-Tretes block was already installedby province government.

Depth of well was varied 6 to 15 meters, depend on shallow aquifer location and condition. Water level of

: : !

0 - _ _

--_--"T_BlDdr.

. . . . KIri. .

］］ｾＮＮｊＮ

__

[image:6.510.42.491.12.614.2]

Fig.2 Irrigation Schemes in Nganjuk district

Table 1Thefeature ofirrigatioDblockinNganjuk area

F"",,", WOW MriC&Jl.Kiri Kuncir-Bodor Ketandan-Trms 1. Main Purpose

• Irrigation 0 0 0 0

• Hydro power generation 0

• Flood control 0 0 0 0

• Recreation 0 0

2. Nwnberofreservoir

• Medium 1(33 MCM)

• Small 2 6

3. Number of I

••

Number ofweir 20 3 20

,

,.

River Sctionol Annual

-

Sctionol

6. Originate of river Kendeng Mountains. Fla... Wilis Mountain Kond<ng

Pandan Mountain&Wilis Mountain

Mountain

7. Sub-basin Widas Warujayeng- Kuncir&.Bodor Widas

Kmooooo" Bodo'

8. Rctardin basin 0

o

28MC 0 0

9. 1m edcommand area 10496

•

12 13.403 3139

groundwater

was

recorded by water logger every six hours. Every week (Thursday) groundwater level

was

manually measwed to calibrate water loggerdata. Water sample

was

taken to measwed pH, temperature

en,

[image:7.491.10.480.3.728.2]

electrical conductivity (EC), nitta.. (No,-N), phosphorus (PD,-P), and chemical oxygen demand (COD).

Table 2 The feature of monitoring well

Irrigation block

Mricao-Kiri

Kuncir-Bodor

Widas

Ketandan-Tretcs

Station name

Sumberkepuh

Tanjungrejo

Ngadihoyo

Banjardowo, Pandean·

Number of

monitoring weD

2

Well depth Casing depth

Parameter

(m) (m)

W 8 Water level,

15 12 pH,

T,

EC,

14 U No,-N,

14" 12.5 PO,-P,COD

Note: • one monitoring well is conductingbyprovince government

•• Monitoringwaslift-up to 6 mafter 6months

To analyze discharge rateinriver, river water level

was

monitored at upper, middle and lower reaches. Four

stations were constructed, which two on upstream, one on middle stream and one on downstream. Water level of

reaches was recorded by water logger every one hour. Every week (Thursday) water level and reach flow was

measured to calibrate waler loggerdata, and discharge rate and rating curve were calculated. Also, water was

sampled to measure pH, temperature

(n,

electrical conductivity (EC), nitrate (No,-N), phospborus (PO,-P), and

chemical oxygen demand (COD).

'-"

-RHer Ｎ ｾ

- 1...ｴｄＺｫｾｃｊｾ｢ｯｬＮｮ､｡ｲｹ

• SlmoI... ｟ ｾ t*ldt

Rainfall and climate data were taken from government monitoring station. Rainfall monitoring station

is

scattered on 45 locations and two climate stations is locatedatupper and lower area.

4. RESULTS

4.1 Groundwater

The monitoring data of groundwaterin 2009-2010 showed the tendency of recharge in rainy season and

uptake in dry season. However, in southern area Mrican-Kiri block, the tendency was not clear. Groundwater

levelsinthe southern area (Mrican-Kiri and Kuncir-Bodor blocks) were higher than those in nonhern area(Widas

and Ketandan-Tretes blocks) indryseason. Monitoringdata on Widas,1Uld Ketandan-Tretes irrigatinn blocks nf

dry season in 2010 showed the groundwater was uptake and utilized as irrigatinn with surface irrigation conjunctively from June to September in2010,and in Kuncir-Bodor irrigation block, the ground waterwas uptake

from July to September in 2010. The year2010 was influenced below La-Nina condition, where rainfall has

occurredindry season.Inthe normal condition. groundwater level pattern is sine curve pattern, where upper peak

on wet season lowerpeakondryseason (Fig.3 (d».

Groundwater was extracted by using pumps. The irrigation well density (fWD) in Table 3 shows that

Kuncir-Bodor block had the highest density (0.76 wellJha) and Ketandan-Tretes block

had

the lowest density

• (0.08welVha). The IWD where related with water extraction was estintated by agricultural area and the number of

irrigation wells. However. fWD in Mrican-Kiri block

was

not related to groundwater extraction, because surface

water was enough for all years. Irrigation wells in Mrican-Kiri block is only used in occasional condition suchas

[image:8.500.27.477.21.735.2]

water al1ocation of surface irrigation was not well doing.

Table 3 Numberorwelland irrigationwelldensity (lWD) per irrigation block

Area Number of well Range&(average) of

Irrigation Block IWD

(ha) (wells)

(weIVha)

Widas 9,889 2,005 0- 1.05 (0.20\

Mrican-Kiri 14,608 5,447 0-2.83(0.37)

Kuncir-Bodor 10 151 7,677 0- 2.99 10.76)

Ketandan-Tretes 4,131 346 0- 3.36 (0.08)

-• Precipitation(mm) .o.'Oundwaler levelUn)

0.'

ｲＺＺ］］］］ｾ［［Ｚ［［［ＺＺ［ＺＺ［ＺＺＺＺＺ［［Ｚ［［［Ｚｾ］］Ｚ［ｲ

'"

-0.0

+

_',

100

-1.5

t_---:,

-r+---""'"

",,.,.-,{

80

ﾷｾＮｏ

60

2010104 2010!U6 2010108 201Ml6 :!OIO,OJ

o

.,

ｴＭＭＭＷｾＭ］ＢＢＧＧＧＧＧＧＧｾＭＧＧＧＧＧＢＧＧｯＢＢＢＬＢｾＢＢＬＢＢｮＧＮ

_{'" ...., ｦ｜ｾ｜ •... :ｾ 100}

• , 80

.,

., t_-,--.N>'+'..,,--'-t_---tt 00

., t_+-,';'-,j

ｦｴＭｾＬｪＭＬＮｪｪＭＭＭｴＭＫＭＭＭＭＭＭＫｈＢ

<t-mr..-JI-H-tlttrr----,-/-;--tl-,---ttI

'7 If ｾｉ ｾ 2Q

-8 - II ｕｉｕＱｩｪｊｉＮＮｬＡｉｌＭＢｲｬｬｬｾｉＮＮ • I 0

2009/10 3009f12 2010.'02 2010104

"

_o

,I '"'

.11 II .1,. '5.5 t -4.6

ｾｲｭｦｫ

ｾＺＺ ｾ

III

ｾｊｬＮ

2009110 2009/12 2010.'02

(a) Tanjungrejo (Kuncir-Bodor block) (b) Ngadiboyo(w.dasblock)

<,.,

Hll 0 100

<1.6 ·1 90

ｾｲｩＬＬ［Ｇｾ Ｎｾ｜ＮＺ ｾ｜ .. 10'

.,

rw'",

"

\

80

-0.8

•

;, :.

\.:

.

..

80

.,

70

.

,

I f " /. '

,

:

.,

00

-1.2 . . . . II 60

.,

"

'\'"

-1.4 <

,

""

II \,!';ot; 4U

-7

'"

-1.6

ｾ

,JIJItL

'1.8 ,'I

ｾＬ

11\

,U "

"

.,

2<1

1

1,...."

,

•

IiiI

10

.,

0 ->0 0

2009/10 2009/12 2010i00 2010!04- 2010Kl6 :lOlO1'O8 _{20000' 2008111}

""'''''

ｾｏｏｏｉＱｉ :lOlO;O5 [image:9.489.12.471.22.578.2]

(c) Sumberkepuh (Mrican-Kiri block) (d) Pandean (Ketandan-Tretes block)

Fig.3 Groundwater level at four blocks

4.2 Surface Water

Discharge rates at four monitoring station were weekly measured. Rating curve was calculated in an

exponential equation by discharge rate and continuous water leveldata. Exponential correlation for the rating

curve of three monitoring stations was satisfied with the coefficient of detennination (R2) of more than 0.94

(Fig.4). Coefficient of determination for the rating curve of Glatik station was 0.74. The coefficient of

determination for GLatik station was lowest, because floodgates were sometime manipulated to open after heavy

rain for avoiding sedimentation on Glatik weir.

Continuous discharge rates were calculated using rating curve model and water level data on each monitoring

station. The discharge rateindry season 2009 (August and September) was almost zero. All rivers in Nganjuk are

seasonal river, where quite small water is found in dry season and flooded condition is found in wet season.

2010/OS

(d)Bolowono (downstrum)

2oOIOlOa

2.010/06

2010/0(1

- - Disc:hUl1Qllnote(JTwn.)

(e) K.ar.mgsemi (middle stmlm)

2.010104

2010/04

(a) Kuncir (upstream)

(b)G1atik(upstream)

-

83-(d) Bolowono(downstream)

(e)Karangsemi(middJe.stream)

2010/02

FIg.4Ratingcurveatupper,middleandlower reaches

(b) G1alik (upstream)

Fig.5Hydrograpb atupper.middle,andlower streams

2009/12 2.009112. 200051110 20009110

Ｚｾｾ

o 10'

?rlOQ/ln ?nonqll". ;<t)1n1t'J:). ".nHlI£lo4 ".nlrvM ".nllYnA

(a) Kuacir(upsmam)

ＮｾＮｷＮＮ _{" - -}

.---.

...

Il40o...

._-

_{" - -}

.

...---

--m

",-un.:lIIII'-1

'"

ｾ

-ｑ｟ＦｾＮｊｉｊｩｩｈｬ｟ /

ｑＮｾｾｾｾＧＭ

i

li'a-.sMl!

!:

•• .. 111111

..

!

•

Ｎｾ［ｬｴＬｉＲＨｉｉﾷＴＮＲｬ｜ＮｾＭ

...

/

..

/

It'_O.Hn/p .

ｾｕ

J

i

•

.

ｾ

'"

1-

ｾＱＶｬｉ

I

i

7

0 '

'.

.'

.! .!

a

•

" a

•

; f - -

ｾ w ｡ｾ

/.

.,1

;I

. j.";

i

.'

.

•

fl.

,

7

'"

1

'"

ｾＯ

,{

,

,

.'w·

,

0,0(1l'I 11.100

...

..

-

...

[image:10.492.29.481.21.726.2]

5. DISCUSSION

Groundwater recharge is an imponant key for the conjunctive use of surface irrigation and groundwater. Itis

difficult to observe groundwater recharge,so thenwecantrytoestimate applying water balance analysis. Water

table of ground water was fluctuated by recharging or uptaking. However, longteonmonitoring wouldbehelpful

to analyze of water balance of shallow groundwater.

Based

on two years data of ground water table in

Pandean,

groundwater balance was aImost same. So then, possibly we may assume that the groundwater recharge was equal

to ground water uptake. And we have to consider of annual rainfall amoWlt, because it is the main source of

groundwater recharge. Based on Fig.3 and Table 4, rainfall and surface injgation have contributed to groundwater

recharge. In September, ordinaty, there wen: no

rain

hut some

rain

was

availablein20 I0 underLaNina condition.

The fluctuation of water table in Widas and Mrican-Kiri blocks in August 2010 showed that ground water table

[image:11.490.11.479.19.438.2]

was

influenced by surface irrigation.

Table 4SurfacewatersupplyinSeptember2009perirrigation block

Uncultivatedarea Cultivatedarea Surface irrigation supply

Irrigation block

(ha) (ha) Ls-1 _mmd-I

Mrican-Kiri 959 13,635 7,390 4.7

Widas 3,523 6,348 842 1.1

Kuncir-Bodor 815 9,351 300 0.3

Ketandan-Tretes 413 3,486 0 0.0

Note: precipitationwas zero at all rainfall gauge stations

The actual discharge rate data showed the infiltration and percolation in beginning rainy season is high (fust

and

second month

of

rainy season).

Base

flow started in

the

second

month

of

rainy

season and thepeakwas

around 6 nun d" in upstream and approximately 2 nun d-Jin whole Widas basin (Fig.S).

The sustainable development of groundwater resource requires continuous quantitative assessment. Some

computer simulation model would be helpful to assess water balance change.

REFERENCES

Bhat, A.,K.Ramo, andK.Kemper (2005) Institutional and Policy Analysis of River Basinｍ｡ｮ｡ｧ･ｭ･ｮｾ the Brantas

•

River Basin,EastJava, Indonesia, World Bank Policy Researcll Working Paper 3611

Bakol1iurtanal (National Coordinating Agency for Survey and Mapping) (200 I) IndonesiaEarthShape Map sheet 1508,

Bogor

BPS of Nganjuk (1992) Nganjuk in Figures 1992. BPS ofNganjuk, Nganjuk BPS ofNganjuk (2009) Nganjuk in Figures 2009. BPS ofNganjuk, Nganjuk BPS (Statistics Indonesia) (2009) Strategic Data of BPS. BPS, Jakarta

Puspowardoyo, R.S. (1984) Indonesia Hydrogeology Map - Kediri Sheel. Departmentad Mining and Energy. Bandung

Ramo,Kikkeri(2004) Brantas River BasinCaseStudy -Indonesia. Background Paper. World Bank, Washington DC,

http://siteresources.worldbank.orgllNTSAREGTOPWATRES/Resourcesllndonesia_BrantasBasinFINAL.pdf.

Acoessed I April 2009

[image:11.490.24.486.108.693.2]

Charles Abernathy (00.), Interseetoral Management of River Basins: proceedings of an international workshop on

"Integrated Water Management in Water-Stressed River Basins in Developing Countries: Strategies for Poverty

Alleviation and Agricultural Growth," Loskop Dam. SouthAfrica,16-21October2000.Colombo. SriLanka:1WMI.

pp.27J-2%