research article changes in stream peak flow and...

Research ArticleChanges in Stream Peak Flow and Regulation in Naoli RiverWatershed as a Result of Wetland Loss

Yunlong Yao12 Lei Wang3 Xianguo Lv2 Hongxian Yu1 and Guofu Li1

1 College of Wildlife Resource Northeast Forestry University Harbin 150040 China2 Key Laboratory of Wetland Ecology and Environment Northeast Institute of Geography and Agroecology CASChangchun Jilin 130012 China

3 College of Architecture and Civil Engineering Heilongjiang Institute of Science and Technology Harbin 150027 China

Correspondence should be addressed to Yunlong Yao ylyao163com

Received 10 February 2014 Revised 1 June 2014 Accepted 2 June 2014 Published 7 July 2014

Academic Editor Ioannis Konstantinou

Copyright copy 2014 Yunlong Yao et al This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

Hydrology helps determine the character of wetlands wetlands in turn regulatewater flowwhich influences regional hydrology Tounderstand these dynamics we studied theNaoli basinwhere from 1954 to 2005 intensivemarshland cultivation took place and thewatershedrsquos wetland area declined from 944times104 ha to 178times104 ha More than 80 of the wetland area loss was due to conversionto farmland especially from 1976 to 1986 The processes of transforming wetlands to cultivated land in the whole Naoli basin andsubbasins can be described using a first order exponential decay model To quantify the effects of wetlands cultivation we analyzeddaily rainfall and streamflow data measured from 1955 to 2005 at two stations (Baoqing Station and Caizuizi Station) We defineda streamflow regulation index (SRI) and applied a Mann-Kendall-Sneyers test to further analyze the data As the wetland areadecreased the peak streamflow at the Caizuizi station increased and less precipitation generated heavier peak flows as the runoffwas faster than beforeThe SRI from 1959 to 2005 showed an increasing trend the SRI rate of increase was 00510a demonstratingthat the watershedrsquos regulation of streamflow regulation was declined as the wetlands disappeared

1 Introduction

Wetlands are a declining resource that occupy less than 9 ofthe earthrsquos land area however their value and contribution tohumanity and the ecosystem are far more valuable than theirsmall area implies [1 2] Wetlands provide such ecosystemservices as improved water quality provision of flood controlmitigation of climate change and groundwater recharge [3ndash7] Concerns about the reduced area and condition of manyof the worldrsquos wetland systems are growing as more andmore wetlands are converted to agricultural land or lost tourbanization [3 8]

Wetlands in catchment areas play an important role inregional hydrological processesWhile hydrology determinesthe character of wetlands wetlands also influence regionalwater flow regimes [4] Inland wetlands are known to providea wide array of hydrological services butmany of the servicesare not well understood [9] Understanding how different

types of wetlands as well as their gain or loss contribute toa watershedrsquos flood mitigation function is a large knowledgegap for policy and decision makers [2]

A basic question remains what proportion of a givenwatershed area should be represented by wetlands to achieveflood control Opinions differ on the advantages and disad-vantages of preserving and restoringwetlands in awatershedrsquosupper reaches [1] but floodplains are known to be criticalin mitigating flood damage as they store large quantities ofwater and effectively reduce the height of flood peaks anddownstream flooding risk Hey and Philippi (1995) suggestedthat restoring approximately 13 million acres (53 million ha)of wetlands in the Upper Mississippi and Missouri Basinswould have provided enough floodwater storage (about1m deep) to accommodate the excess river flow from thedisastrous flood in Midwestern USA in 1993 [10] If those53 million hectares were added to the existing 77 millionhectares in the region an estimated 7 of the watershed

Hindawi Publishing Corporatione Scientific World JournalVolume 2014 Article ID 209547 10 pageshttpdxdoiorg1011552014209547

2 The Scientific World Journal

3

2

1

4

Baoan

Youyi

Fujin

Baoqing

0 25 50125

Weather stationHydrological station

RiverSubbasin

Qixing

River

Rive

r

Naoli

CaizuiziInner MongoliaHeilongjiang

Province

Jilin Province

Liaoning Province

Naoli watershedSanjiang PlainNortheast of China

131∘E 132∘E

45∘ N133∘E

132∘E 133∘E

46∘ N

46∘ N

47∘ N

47∘ N

48∘ N 134∘E

5

(km)

Figure 1 The location sketch of study area

would be sufficient to address even extreme event floods ona large scale Mitsch and Gosselink suggested that a range of3ndash7 of temperate-zone watersheds should be occupied bywetlands to provide adequate flood control and water qualityvalues for the landscape [1]

Sanjiang Plain located in the northeast of HeilongjiangProvince Northeast China previously contained the largestcontinuous area of freshwater wetlands in Chinamdashit was ina completely natural and untouched condition before the1950s From the late 1950s to the early 1990s however a largenumber of farms were established across the plain leading tothe loss of wetlands (nearly 80 of the freshwater wetlandsin Sanjiang Plain have been transitioned to other uses) and adecline in the condition of the remaining wetlands due to thechanges in hydrology

At a regional scale the ecosystem services providedby the wetlands remaining have declined dramatically Thetotal annual ecosystem service values in Sanjiang Plainhave declined by about 40 between 1980 and 2000 Thissubstantial decline is largely attributed to the loss of wetlands[11] Due to limited data available from Northeast Chinafew reports are available to describe the impacts of wetlandloss on the peak flow of Naoli River Basin as the wetlandshave been converted to cropland The whole water storagecapability of wetland of Sanjiang Plain was originally 1715times 108m3 in 1950s [12] This storage capability declined withthe cultivation of wetland areas which has most likelyproduced heavier peak flows during extreme rainfall eventsThe annual runoff declined dramatically since 1950s and thehydrological regime has also changed [13ndash18] However the

impact of wetland cultivation on the watershedrsquos peak flowand regulation has not yet been quantified

This study focused on the effect of wetland cultivationon the peak flow and regulation function of the NaoliRiver catchment The study goal was to assess whetherthe hydrological function of wetlands especially the floodcontrol function has declined as a result of wetland loss overthe last 50 years

2 Study Area

TheNaoli River watershed (131∘ 311015840ndash134∘ 101015840E and 45∘431015840ndash47∘451015840N) is located within the Sanjiang Plain in HeilongjiangProvince (Figure 1) covering 242 times 104 km2 It is estimatedthat mountains occupy 383 of the total area the plainoccupies 617 The Naoli River the primary tributary ofthe Wusuli River originates from the Qliga Mountain ofthe Wanda Mountain in Boli County Heilongjiang Provinceand flows into the Wusuli River in the Dongrsquoan Town ofRaohe CountyThe riverrsquos overall length is 283 kmThe NaoliRiver watershed lies in a temperate zone with a continentalmonsoon climate The mean annual temperature is 16∘Cwith an average temperature of minus216∘C in January and 214∘Cin JulyThemean annual precipitation is 565mmwhilemeanannual evaporation is 5424mm The terrain in the NaoliRiver watershed is flat and low with an average altitude ofabout 60m The landscape is characterized by an extensiveriver floodplain with widely distributed dish-shaped swalesand limited surface runoff A predominantly clay substrate

The Scientific World Journal 3

Table 1 Data sources on daily precipitation streamflow and land use

Data type Station name Year Data provider

PrecipitationBaoqing 1956 to 2005

Heilongjiang Sharing Service Center of Weather Scientific DataYouyi 1952 to 2005Fujin 1961 to 2005

Runoff

Baoqing 1955 to 2005

Department of Hydrology of Heilongjiang ProvinceBaoan 1957 to 2005Caizuizi 1956 to 2005

Hongqiling 1971 to 2005Land use mdash 1950s 1980 1996 2000 2005 China Wetland Scientific Database

hampers surface water infiltration which originally led to aformation of extensive wetlands (including different kinds offreshwater marshland riverine wetland and ponds) origi-nally taking up one-fourth (or 944 times 104 ha) of the SanjiangPlain Unique natural and climatic conditions once created arich area of wetlands and a unique ecological environment Inparticular in the vast plain region which represents a broadriver floodplain different kinds of wetlands were formedBecause of subsequent agricultural activities however theplainrsquos total wetland area in 2000 was 34600 km2 which wasonly 367 of the original area of 94400 km2 in 1954 Nearly80 of the area was turned into croprsquos land during this timeAs a result the structure and function of the watershed havechanged dramatically

Based on the location of the hydrological stations forstudy purposes we divided the basin into five subbasinsmarked by Arabic numerals as shown in Figure 1 There weretwo subbasins in the headwaters two subbasins in transferzone and one in the depositional zone

3 Data and Method

31 Data Source There are only four hydrological stationsin the Naoli River watershed Baoqing Baorsquoan Caizuiziand Hongqiling Stations (see Figure 1) Baoqing and BaorsquoanStations are located in the upper reaches of Naoli River andCaizuizi and Hongqiling are located in the middle reachesData from Baorsquoan Station were insufficient and could not beused Data fromHongqiling Stationwere also not appropriatefor this study due to a shorter observation period and smallercatchment area As such for this study runoff data wereused from Baoqing Station (catchment area of 3689 km2)and the Caizuizi Station (catchment area of 20796 km2)Daily measured runoff data from 1956 to 2005 were usedfrom Baoqing Station and Caizuizi Station in Naoli Riverwatershed from which we calculated monthly and annualmean runoff

Daily precipitation data from 1956 to 2005were used fromweather stations in Baoqing County Youyi County and FujinCity provided by the Heilongjiang Sharing Service Centerof Weather Scientific Data Precipitation data from BaoqingStation include the annual mean precipitation measuredin the weather station of Baoqing County from 1956 to

2005 Additionally precipitation from Caizuizi Station isrepresented by the average of the annual mean precipitationmeasured in the Baoqing Youyi and Fujin weather stationsSources of the hydrological data and precipitation can befound in Table 1

The land use datasets of the watershed were obtainedduring relatively cloud-free days in September 1980 (MSSdata) August 1996 (TM data) September 2000 (TM data)and September 2005 (TMdata) Land use data from the 1950swas derived using a 1950rsquos topographic map All the landuse datasets were provided by the China Wetland ScientificDatabase

32 Method

321 Wetland Change Detection The land use datasets pro-vided by the China Wetland Scientific Database were alreadyclassified into seven land usecover categories woodlandgrassland farmland water body wetland residential landand barren land For the purposes of our research weregrouped the classification into two groups wetlands andnonwetlands The total wetland areas during the differentperiods were calculated using ARCINFO (ESRI 1994) Geo-graphical Information System (GIS) software the wetlandareas of the whole basin and subbasins were also comparedduring the different periods

322 Mann-Kendall-Sneyers Test Many time-series analysesmethods are used by different researchers [19ndash22] In thisstudyTheMann-Kendall-Sneyers test had the greatest abilityto test the trend of hydrological time series data [23ndash25] Assuch the test was used to analyze the phase features of theannual mean runoff records from the Baoqing hydrologicalstation and the Caizuizi hydrological station in the NaoliRiver watershed

Let 1199091 1199092 119909

119899be the time series data points For each

element 119909119894 we computed the numbers 119898

119894of elements 119909

119895

preceding it (119895 lt 119894) such that 119909119895lt 119909119894 Under the null

hypothesis (no trend) the test statistic

119905119896=

119896

sum

119894=1

119898119894 (2 le 119896 le 119899) (1)


is normally distributed with mean and variance given by thefollowing equations

119905119896= 119864 (119905

119896) =119896 (119896 minus 1)

4

Var (119905119896) =119896 (119896 minus 1) (2119896 + 5)

72

(2)

Let

119906119896=119905119896minus 119905119896

radicvar (119905119896)

(3)

be the normalized variable which is the forward sequenceThe backward sequence 119906lowast

119896is calculated using the same

equation but with a reversed series of dataWhen the null hypothesis is rejected (ie if any of the

points in the forward sequence are outside the confidenceinterval) it indicates an increasing (119906

119896gt 0) or a decreasing

(119906119896lt 0) trend The sequential version of the test enables

detection of the approximate time of trend occurrence bylocating the intersection of the forward and backward curvesof the test statistic If the intersection occurs within theconfidence interval then it indicates a change point [26 27]

323 Definition of Streamflow Regulation Index Accordingto the hydrological theory the runoff is tightly correlatedto the precipitation under the nature condition When theprecipitation varies the runoff will correspond To quantifythe impacts of wetland loss on the streamflow regulationwe defined the streamflow regulation index through thefollowing formula

SRI =119877cv119875cv

While 119877cv =119877sd119877avg 119875cv =

119875sd119875avg

(4)

where SRI was the streamflow regulation index 119877cv wasthe coefficient of variation of runoff 119877sd was the standarddeviation of runoff and 119877avg was the average of the runoff119875cv was the coefficient of variation of precipitation 119875sd wasthe standard deviation of precipitation and 119877avg was theaverage of the precipitation SRI can be interpreted as followswhen the variation coefficient of precipitation increased butthe variation coefficient of runoff was not equally increasedthen the streamflow regulation index became smaller sothe ability of the streamflow regulation of the watershedwas increased otherwise it was decreased The daily runoffand precipitation of Caizuizi Station was used from June toNovember from 1959 to 2005

4 Results

41 The Process of Wetland Cultivation in Subbasins The areaofwetlands in each subbasinwas different in 1954Table 2Thearea of wetlands in subbasins 3 and 5 was higher than othersubbasins (1 2 4) the percentage respectively was 518

Table 2 Percentage of wetlands in each subbasin in 1954

Subbasin name Subbasinnumber

Area of subbasin(km2)

Percentage ofwetlands ()

Baorsquoan 1 13542 66Baoqing 2 36842 94Caizuizi 3 151171 518Hongqiling 4 11028 87Xiayou 5 25536 425

and 425 Individual subbasin areas are shown in Figure 2There were no hydrological observations in subbasin 5 Thetotal area of subbasins 2 and 3 is 188013 km2 accounting fornearly 80 of whole catchment So to compare wetland lossimpacts on hydrological characteristics wetland cultivationof the whole catchment and subbasins 2 and 3 was analyzedseparately

The loss of wetlands across the full Naoli watershed wasdramatic between the 1950s and 2005 The wetland areadeclined from 944 times 104 ha to 178 times 104 ha more than 80of the wetlands were lost The loss rate between 1976 and1986 was more rapid than during other years The dynamicsin the two subbasins included in the study were almost thesame the area of wetland declined from 28 times 104 ha and 634times 104 ha to 08 times 104 ha and 3889 times 104 ha in subbasins 2and 3 respectively about 80 of the wetland was convertedto farmland The percentage of wetland declined to 105in subbasin 3 After 1995 the area of wetland declined lessrapidly and wetland cultivation nearly stopped

The process of wetland loss in the full basin and subbasinscan be described using first order exponential decay modelthe fitting degree was high (whole basin 1198772 = 097 subbasin2 1198772 = 084 and subbasin 3 1198772 = 097) The rapid decreasein the number and areas of marshes was largely attributedto extensive agricultural reclamation under the ldquoFood Firstrdquoagricultural policy This resulted in many negative ecologicalconsequences such as extreme peak flow and habitat loss

42 Changes in the Peak Flow

421 Variation of Annual Maximum Peak Flow The annualmaximum peak flow was derived from the daily runoff datacollected between June andNovember from 1959 to 2005Themaximumflowof a day in a year is set as the annualmaximumpeak flow of that year Based on the annual precipitation wedivided the 47 study years into three types of hydrologicalyears wet years dry years and normal years If the annualprecipitation of one year was 10 percent greater than theaverage annual precipitation this year was defined as a wetyear if annual precipitation was 10 percent less than theaverage annual precipitation this year was defined as a dryyearThe rest of the years the years where rainfall was within10 above or below average were classified as normal years

The variation of these types of years is shown in Figure 3During the wet years the peak flows in Baoqing Station(upstream) were greater than those in Caizuizi Station (mid-stream) in most of the years The situation was opposite


Whole basin Subbasin 3 Subbasin 2

R2 = 097R2 = 097 R2 = 084

0

10

20

30

40

50

60

70

80

90

0

10

20

30

40

50

60

70

80

90

Year Year Year

0

1

2

3

4

1954 1976 1986 1995 2000 2005 1954 1976 1986 1995 2000 2005 1954 1976 1986 1995 2000 2005

Are

a (10

4ha

)

Are

a (10

4ha

)

Are

a (10

4ha

)

y = 12543exp(minusx263) + 912y = 12290exp(minusx407) ndash 1626 y = 585exp(minusx183) + 023

Figure 2 Wetlands cultivation in the whole basin subbasin 2 and subbasin 3

during the dry year As a whole there were 22 years whenpeak flows in Baoqing Station were greater than those inCaizuizi Station The maximum peak flow of 1 010m3s inBaoqing Station happened in 1964 between 1959 and 2005while the peak flow was only 547m3s in Caizuizi Stationwhich is a lower value by 46 Because of the wetlandcultivation the peak flow of Caizuizi Station became greaterThe maximum peak flow in Caizuizi Station occurred in 1981at 750m3s while the flow in Baoqing Station was 629m3sThe watershedrsquos regulation function of peak flow declined asthe wetland was lost

Using time series of annual maximum peak flows fromBaoqing Station and Caizuizi Station we also comparedaverage maximum peak flow from four overlapping 20 yrperiods (1959ndash1970 (hereafter called the 1960s) 1970ndash1990(1970s) 1980ndash2000 (1980s) and 1990ndash2010 (1990s)) (seeFigure 4) In general maximum flow events were largest in1960s and then declined in 1970s increased in 1980s anddecreased in 1990s These variations can be attributed to thedifference of weather patterns and wetland loss Howeverthe comparison of average maximum rainfall from BaoqingStation and Youyi Station (representing the precipitationregime of Caizuizi subbasin) showed no such variation (seeFigure 4)

422 Different Runoff Process at Same Precipitation RegimeThe rainfall regime was almost the same in 1959 and 1981The annual precipitation was a little greater in 1959 than thatin 1981 respectively (765mm versus 726mm) The monthlyprecipitation is shown in Figure 5 it is clearly almost thesame However the runoff process was different especially interms of peak flow

Daily precipitation and runoff details are summarizedin Figure 6 the results are summarized in the followingthree points First the maximum peak flow was differentbetween 1959 and 1981 the difference was an increase ofnearly 50 The maximum peak flow was 514m3s in 1959it was 750m3s in 1981 Second the rise-time from dailymean runoff to the peak flow was differentThe rise-time was36 days in 1959 it became shorter in 1981 falling to about

18 days The time from the peak flow to daily mean runoffwas also different It was longer in 1981 than that in 1959 at73 days and 54 days respectively This demonstrates that asmore water flowed out of watershed the wetlandrsquos storagecapability dramatically declined Third the total amount ofprecipitation experienced when runoff reached its maximumwas also different The precipitation was 737mm in 1959representing 963 of total precipitation of this year Theprecipitation was 632mm in 1981 representing 855 of totalprecipitation Less precipitation could generate heavier peakflow

43 Changes in Streamflow Regulation In 1954 most of thearea (518) in subbasin 3 was still covered by wetlands thesewetlands were subsequently removed and were degradedmore rapidly than those in other subbasins As such weonly analyzed the streamflow regulation index of subbasin3 (Caizuizi Station) in this section The variation coefficientof runoff and rainfall is provided in Figure 7 The variationcoefficient of runoff showed an ascending trend the rainfallwas opposite with a descending trend However results ofMann-Kendall-Sneyers test showed that the ascending trendof variation coefficient of runoff was not obvious (Z = 1161198861= 012 gt 005) the descending trend of coefficient of

variation of rainfall was also not statistically significant (Z =minus108 119886

1= 014 gt 005) When the impacts of rainfall were

eliminated the streamflow regulation index had an obviouslyascending trend (Figure 7)

The results of Mann-Kendall-Sneyers test showed anascending trend in the streamflow regulation index (Z =172 119886

1= 004 lt 005) Using linear regression we

found that the streamflow regulation growth rate index was00510a Despite many water conservancy projects in thiswatershed the streamflow regulation function of watershedstill declined

These results showed an increase in the runoff coefficientof variation over time while the peak flow was decreasingThis seems contradictory however the data analysis sug-gests three main reasons for this (1) The runoff variation


Boaqing Station Caizuizi Station Boaqing Station Caizuizi Station Boaqing Station Caizuizi Station

0

200

400

600

800

Wet year Dry year

Max

flow

(m3s

)

1000

0

200

400

600

800

1000

Whole time

0

200

Figure 3 Maximum peak flow of Baoqing Station and Caizuizi Station from June to November between 1959 and 2005

0

0 0

200

400

600

0

200

400

600

800

1000

Max

flow

(m3s

)M

ax r

ainf

all (

mm

)

20

40

5060

80

100100

120

1959ndash1980 1970ndash1990 1980ndash2000 1990ndash2005 1959ndash1980 1970ndash1990 1980ndash2000 1990ndash2005


Baoqing peak flow Caizuizi peak flow

Baoqing max rainfall Youyi max rainfall

Period

Period Period

Period

Figure 4 Peak flow andmaximum rainfall magnitude across four time periods Boxplots represent data fromdifferent periods the horizontalline in each boxplot is the median while the square box holds the mean


0

50

100

150

200

1959

1981

Prec

ipita

tion

(mm

)

Month1 2 3 4 5 6 7 8 9 10 11 12

Figure 5 Annual precipitation distribution in Caizuizi Station in 1951 and 1981

600500400300

100200

0

Runo

ff (m

3s

)

RunoffPrecipitation

50

40

30

20

10

0 Prec

ipita

tion

(mm

)

Day of the year0 50 100 150 200 250 300 350

(a)

600700800

500400300

100200

0

Runo

ff (m

3s

)

RunoffPrecipitation

50

40

30

20

10

0 Prec

ipita

tion

(mm

)

Day of the year0 50 100 150 200 250 300 350

(b)

Figure 6 Daily rainfall and runoff in Caizuizi Station (a) 1959 (b) 1981

coefficient showed an ascending trend However the Mann-Kendall-Sneyers test revealed that the ascending trend ofvariation coefficient of runoff was not significant (2) Inorder to control flood and drought many water conservancyprojects were built including more than 10 reservoirs Long-touqiaoReservoir built in 2003 is the largest reservoir in San-jiang Plain and plays an important role in flood prevention(3) As discussed previously the lack of data availability andquality presents study limitations The previously discussedstudies of peak flow responses have reliedmainly on statisticalmethods and therefore have been limited by the availability ofthe data There is only one hydrological station in the middleof the river as such someof the detailed hydrological changesexperienced during wetland cultivation may be missed

5 Discussion

51 The Contribution of Wetland Transformation From theprevious section we know that the maximum rainfall doesnot vary significantly between the different time periodsHowever during the time of wetland loss the relationshipsbetween maximum flow and the maximum rainfall becomemore tightly connectedThe linear regression coefficient (R2)increases especially from the 1970s to 1990s (see Figure 8)

and the R2 increased from 012004 to 033049 in BaoqingStationCaizuizi StationThis means that the runoff increasesin response to the rainfall as the wetland loss increases

Following the conversion of wetlands to croplands San-jiang Plain became an important commodity grain produc-tion base in China [28 29] The area of farmland in Naoliwatershed accounts for one-third of the total farmland ofSanjiang Plain As such the impacts of flood damage mustbe considered as that damage directly impacts national foodsecurity

52 The Impact of Wetlands Loss on the SRI To clearlyunderstand the relationships between wetlands loss and SRIwe used SRI time series from Caizuizi Station to calculatethe average SRI from the four overlapping 20 yr periodsdescribed above The scatter plot of the wetland area ofsubbasin 3 against the SRI shows a negative relationshipbetween the wetland area and SRI (Figure 9) The streamregulation function decreased as the wetlands were lost fromsubbasin 3

It is widely recognized that wetlands provide importanthydrologic functions in a watershed [30ndash32] While theimportance of individual wetlands formitigating flood inten-sity and duration is understood the degree to which wetland


CV

6

4

2

0

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005

y = 00087x minus 1646

R2 = 0019

(a)

CV

4

3

2

1

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005

y = minus00089x + 2446

R2 = 0027

(b)

SRI

20

15

10

05

00

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005

y = 00049x minus 926

R2 = 0041

(c)

Figure 7 Variation coefficient of runoff rainfall and SRI in Caizuizi Station (a) runoff (b) rainfall (c) SRI

Period Period Period PeriodBa

oqin

g St

atio

nCa

izui

zi S

tatio

nSt

atio

n na

me

Stat

ion

nam

e

Max rainfall (mm) Max rainfall (mm) Max rainfall (mm) Max rainfall (mm)

0

200

400

600

800

0

200

400

600

800

Y = minus6953 + 5271 lowast X

R2 = 0227

Y = 1523 + 273 lowast X

R2 = 0126


R2 = 0350


R2 = 0338


R2 = 0237

Y = 3734 + 2751 lowast X

R2 = 0047

Y = 4831 + 2224 lowast X

R2 = 0079


R2 = 0490

0 20 40 60 80 0 20 40 60 80 0 20 40 60 80 0 20 40 60 80

1959ndash1980 1970ndash1990 1980ndash2000 1990ndash2005

Max

flow

(m3s

)M

ax fl

ow (m

3s

)

Figure 8 The relationships between maximum flow and maximum rainfall in different period


045

040

035

030

025

30 40 50 60 70 80

SRI

R2 = 098

P lt 001

Wetlands area (104 ha)

Figure 9 Scatter plot of wetlands area in subbasin 3 and the SRI ofdifferent 20 yr periods

development affects flooding at the watershed or ecosystemlevel is rare From the literature review we found somesimilar results Brody et al (2007) examined the relationshipbetween wetland alteration and coastal watershed floodingin Texas and Florida over a 12-year period and found thatspecific types of federal permits exacerbate flooding events[33] Using the HEW concept in SWAT to assess the effectsof wetland restoration for a 4506 km2 in Minnesota Wanget al (2010) found that a reduction of approximately 10ndash20of the wetlands in the study area resulted in a considerableincrease in peak discharge [34] Our research result is anotherevidence to prove the hydrological service of wetland in awatershed

Because of the limitation of the statistic methods wecould not quantify the impacts of wetland loss on thehydrological process In the future we recommend usingdistributed hydrological model such as the Soil and WaterAssessment Tool (SWAT) [35] to analyze the impacts ofwetland lossrestoration on the hydrological process But lackof hydrological and meteorological data is a major challengefor using hydrological model in this region of China

6 Conclusion

This study used the Naoli River watershed to study theprocess of wetland loss and the impact of that loss onthe peak streamflow and regulation Study findings providea scientific foundation that may help inform local waterresources management Key findings were as follows

(1) Wetlands in the study area declined from 944times104 hato 178 times 104 ha between 1950s and 2005 reflecting

a loss of approximately 80 the loss rate was mostrapid from 1976 to 1986

(2) Over the period of wetland loss the peak flow atCaizuizi Station increased particularly during dryyears lower precipitation generated heavier peakflows and runoff after rainfall events increasedStreamflow regulation declined with the decrease inwetland area the SRI growth rate was calculatedas 00510a and was tightly related to wetland lossWatershed manager must remain attentive to therapid impacts of extreme rainfall events in the future

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Acknowledgments

This work was supported by the Fundamental ResearchFunds for the Central Universities (DL12CA08) NationalNature Science Foundation (41301081 41101177) and KeyLaboratory Program of the Chinese Academy Science(WELF-2009-B-001) Special thanks are due to Dr MartaTreskonova for constructive comments and substantial lan-guage editing

References

[1] W J Mitsch and J G Gossilink ldquoThe value of wetlands Impor-tance of scale and landscape settingrdquo Ecological Economics vol35 no 1 pp 25ndash33 2000

[2] J B Zedler and S Kercher ldquoWetland resources status trendsecosystem services and restorabilityrdquo Annual Review of Envi-ronment and Resources vol 30 pp 39ndash74 2005

[3] J R Jensen K Rutchey M S Koch and S Narumalani ldquoInlandwetland change detection in the EvergladesWater ConservationArea 2A using a time series of normalized remotely senseddatardquo Photogrammetric Engineering and Remote Sensing vol 61no 2 pp 199ndash209 1995

[4] W J Mitsch and J G GosselinkWetlands John Wiley amp SonsNew York NY USA 2007

[5] P A Keddy Wetland Ecology Principles and ConservationCambridge University Press 2nd edition 2010

[6] W JMitschWetland Ecosystems JohnWiley amp Sons HobokenNJ USA 2009

[7] W Lewis Wetlands Characteristics and Boundaries NationalAcademies Press 1995

[8] A Gerakis and K Kalburtji ldquoAgricultural activities affectingthe functions and values of Ramsar wetland sites of GreecerdquoAgriculture Ecosystems and Environment vol 70 no 2-3 pp119ndash128 1998

[9] Millennium Ecosystem Assessment Ecosystems and HumanWell-Being Wetlands and Water Synthesis World ResourcesInstitute Washington DC USA 2005

[10] D L Hey and N S Philippi ldquoFlood reduction through wetlandrestoration the UpperMississippi River Basin as a case historyrdquoRestoration Ecology vol 3 no 1 pp 4ndash17 1995


[11] Z Wang B Zhang S Zhang et al ldquoChanges of land use and ofecosystem service values in Sanjiang Plain Northeast ChinardquoEnvironmental Monitoring and Assessment vol 112 no 1ndash3 pp69ndash91 2006

[12] L Xingtu ldquoWater storage and flood regulation functions ofmarsh wetland in the Sanjiang Plainrdquo Wetland Science vol 5no 1 pp 64ndash68 2007

[13] Z Liu X Lu S Yonghe C Zhike H Wu and Y ZhaoldquoHydrological evolution of wetland in Naoli River basin and itsdriving mechanismrdquoWater Resources Management vol 26 no6 pp 1455ndash1475 2012

[14] X Song X Lu Z Liu and Y Sun ldquoRunoff change of Naoli Riverin Northeast China in 1955ndash2009 and its influencing factorsrdquoChinese Geographical Science vol 22 no 2 pp 144ndash153 2012

[15] H J Luan Zhaoqing W Deng Z Guangxin and Z DeminldquoThe influence of human activities on the runoff regimes ofnaoli riverrdquo Resources Science vol 29 pp 46ndash51 2007

[16] Y Yunlong L Xianguo and W Lei ldquoAssessing the impacts ofclimate change on the streamflow ofNaoli Riverrdquo Journal of EastChina Normal University (Natural Science) vol 2009 no 3 pp153ndash159 2009

[17] Y Yunlong L Xianguo and W Lei ldquoTendency and periodicityof annual runoff variations in Naoli River watershed from 1956to 2005rdquo Resources Science vol 31 pp 648ndash655 2009

[18] Y Yao X Lu L Wang and H Yu ldquoA quantitative analysis ofclimate change impacts on runoff in Naoli Riverrdquo Advances inWater Science vol 21 no 6 pp 765ndash770 2010

[19] A Worman G Lindstrom A Akesson and J Riml ldquoDriftingrunoff periodicity during the 20th century due to changingsurface water volumerdquoHydrological Processes vol 24 no 26 pp3772ndash3784 2010

[20] R Blender and K Fraedrich ldquoLong-termmemory of the hydro-logical cycle and river runoffs in China in a high-resolutionclimatemodelrdquo International Journal of Climatology vol 26 no12 pp 1547ndash1565 2006

[21] J Li and P Feng ldquoRunoff variations in the Luanhe River Basinduring 1956ndash2002rdquo Journal of Geographical Sciences vol 17 no3 pp 339ndash350 2007

[22] M Nakken ldquoWavelet analysis of rainfall-runoff variabilityisolating climatic from anthropogenic patternsrdquo EnvironmentalModelling and Software vol 14 no 4 pp 283ndash295 1999

[23] M G Kendall Rank Correlation Measures Charles GriffinLondon UK 1975

[24] H BMann ldquoNonparametric tests against trendrdquo Econometricavol 13 pp 245ndash259 1945

[25] A H Matonse and A Frei ldquoA seasonal shift in the frequencyof extreme hydrological events in southern New York StaterdquoJournal of Climate vol 26 pp 9577ndash9593 2013

[26] G R Demaree and C Nicolis ldquoOnset of Sahelian droughtviewed as a fluctuation-induced transitionrdquo Quarterly Journalof the Royal Meteorological Society vol 116 no 291 pp 221ndash2381990

[27] J M Moraes G Q Pellegrino M V Ballester L A MartinelliR L Victoria and A V Krusche ldquoTrends in hydrologicalparameters of a southern Brazilian watershed and its relationto human induced changesrdquoWater Resources Management vol12 no 4 pp 295ndash311 1998

[28] S Zhang X Na B Kong et al ldquoIdentifying wetland change inChinarsquos Sanjiang Plain using remote sensingrdquoWetlands vol 29no 1 pp 302ndash313 2009

[29] W Aihua Z Shuiqing and H Yanfen ldquoStudy on dynamicchange of mire in Sanjiang Plain based on RS and GISrdquo ScientiaGeographica Sinica vol 5 pp 636ndash640 2002

[30] M Acreman and J Holden ldquoHow wetlands affect floodsrdquoWetlands vol 33 no 5 pp 773ndash786 2013

[31] T A De Laney ldquoBenefits to downstream flood attenuation andwater quality as a result of constructed wetlands in agriculturallandscapesrdquo Journal of Soil andWater Conservation vol 50 no6 pp 620ndash626 1995

[32] E Ranieri A Gorgoglione and A Solimeno ldquoA comparisonbetween model and experimental hydraulic performances ina pilot-scale horizontal subsurface flow constructed wetlandrdquoEcological Engineering vol 60 pp 45ndash49 2013

[33] S D Brody W E Highfield H-C Ryu and L Spanel-WeberldquoExamining the relationship between wetland alteration andwatershed flooding in Texas and Floridardquo Natural Hazards vol40 no 2 pp 413ndash428 2007

[34] X Wang S Shang Z Qu T Liu A M Melesse and WYang ldquoSimulated wetland conservation-restoration effects onwater quantity and quality at watershed scalerdquo Journal ofEnvironmental Management vol 91 no 7 pp 1511ndash1525 2010

[35] M Babbar-Sebens R C Barr L P Tedesco and M AndersonldquoSpatial identification and optimization of upland wetlandsin agricultural watershedsrdquo Ecological Engineering vol 52 pp130ndash142 2013

Submit your manuscripts athttpwwwhindawicom

Forestry ResearchInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Environmental and Public Health

Journal of



EcosystemsJournal of


MeteorologyAdvances in

EcologyInternational Journal of


Marine BiologyJournal of


Hindawi Publishing Corporationhttpwwwhindawicom

Applied ampEnvironmentalSoil Science

Volume 2014

Advances in


Environmental Chemistry

Atmospheric SciencesInternational Journal of



Waste ManagementJournal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal of

Geophysics


Geological ResearchJournal of

EarthquakesJournal of


BiodiversityInternational Journal of


ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

OceanographyInternational Journal of


The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of Computational Environmental SciencesHindawi Publishing Corporationhttpwwwhindawicom Volume 2014


ClimatologyJournal of


3

2

1

4

Baoan

Youyi

Fujin

Baoqing

0 25 50125

Weather stationHydrological station

RiverSubbasin

Qixing

River

Rive

r

Naoli

CaizuiziInner MongoliaHeilongjiang

Province

Jilin Province

Liaoning Province

Naoli watershedSanjiang PlainNortheast of China

131∘E 132∘E

45∘ N133∘E

132∘E 133∘E

46∘ N

46∘ N

47∘ N

47∘ N

48∘ N 134∘E

5

(km)

Figure 1 The location sketch of study area

would be sufficient to address even extreme event floods ona large scale Mitsch and Gosselink suggested that a range of3ndash7 of temperate-zone watersheds should be occupied bywetlands to provide adequate flood control and water qualityvalues for the landscape [1]

Sanjiang Plain located in the northeast of HeilongjiangProvince Northeast China previously contained the largestcontinuous area of freshwater wetlands in Chinamdashit was ina completely natural and untouched condition before the1950s From the late 1950s to the early 1990s however a largenumber of farms were established across the plain leading tothe loss of wetlands (nearly 80 of the freshwater wetlandsin Sanjiang Plain have been transitioned to other uses) and adecline in the condition of the remaining wetlands due to thechanges in hydrology

At a regional scale the ecosystem services providedby the wetlands remaining have declined dramatically Thetotal annual ecosystem service values in Sanjiang Plainhave declined by about 40 between 1980 and 2000 Thissubstantial decline is largely attributed to the loss of wetlands[11] Due to limited data available from Northeast Chinafew reports are available to describe the impacts of wetlandloss on the peak flow of Naoli River Basin as the wetlandshave been converted to cropland The whole water storagecapability of wetland of Sanjiang Plain was originally 1715times 108m3 in 1950s [12] This storage capability declined withthe cultivation of wetland areas which has most likelyproduced heavier peak flows during extreme rainfall eventsThe annual runoff declined dramatically since 1950s and thehydrological regime has also changed [13ndash18] However the

impact of wetland cultivation on the watershedrsquos peak flowand regulation has not yet been quantified

This study focused on the effect of wetland cultivationon the peak flow and regulation function of the NaoliRiver catchment The study goal was to assess whetherthe hydrological function of wetlands especially the floodcontrol function has declined as a result of wetland loss overthe last 50 years

2 Study Area

TheNaoli River watershed (131∘ 311015840ndash134∘ 101015840E and 45∘431015840ndash47∘451015840N) is located within the Sanjiang Plain in HeilongjiangProvince (Figure 1) covering 242 times 104 km2 It is estimatedthat mountains occupy 383 of the total area the plainoccupies 617 The Naoli River the primary tributary ofthe Wusuli River originates from the Qliga Mountain ofthe Wanda Mountain in Boli County Heilongjiang Provinceand flows into the Wusuli River in the Dongrsquoan Town ofRaohe CountyThe riverrsquos overall length is 283 kmThe NaoliRiver watershed lies in a temperate zone with a continentalmonsoon climate The mean annual temperature is 16∘Cwith an average temperature of minus216∘C in January and 214∘Cin JulyThemean annual precipitation is 565mmwhilemeanannual evaporation is 5424mm The terrain in the NaoliRiver watershed is flat and low with an average altitude ofabout 60m The landscape is characterized by an extensiveriver floodplain with widely distributed dish-shaped swalesand limited surface runoff A predominantly clay substrate






Runoff






3 Data and Method





32 Method



Let 1199091 1199092 119909




119895



119905119896=

119896

sum

119894=1

119898119894 (2 le 119896 le 119899) (1)



119905119896= 119864 (119905

119896) =119896 (119896 minus 1)

4

Var (119905119896) =119896 (119896 minus 1) (2119896 + 5)

72

(2)

Let

119906119896=119905119896minus 119905119896

radicvar (119905119896)

(3)









SRI =119877cv119875cv

While 119877cv =119877sd119877avg 119875cv =

119875sd119875avg

(4)


4 Results















R2 = 097R2 = 097 R2 = 084

0

10

20

30

40

50

60

70

80

90

0

10

20

30

40

50

60

70

80

90

Year Year Year

0

1

2

3

4

1954 1976 1986 1995 2000 2005 1954 1976 1986 1995 2000 2005 1954 1976 1986 1995 2000 2005

Are

a (10

4ha

)

Are

a (10

4ha

)

Are

a (10

4ha

)


















0

200

400

600

800

Wet year Dry year

Max

flow

(m3s

)

1000

0

200

400

600

800

1000

Whole time

0

200


0

0 0

200

400

600

0

200

400

600

800

1000

Max

flow

(m3s

)M

ax r

ainf

all (

mm

)

20

40

5060

80

100100

120





Period

Period Period

Period



0

50

100

150

200

1959

1981

Prec

ipita

tion

(mm

)

Month1 2 3 4 5 6 7 8 9 10 11 12


600500400300

100200

0

Runo

ff (m

3s

)

RunoffPrecipitation

50

40

30

20

10

0 Prec

ipita

tion

(mm

)

Day of the year0 50 100 150 200 250 300 350

(a)

600700800

500400300

100200

0

Runo

ff (m

3s

)

RunoffPrecipitation

50

40

30

20

10

0 Prec

ipita

tion

(mm

)

Day of the year0 50 100 150 200 250 300 350

(b)



5 Discussion







CV

6

4

2

0

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005

y = 00087x minus 1646

R2 = 0019

(a)

CV

4

3

2

1

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005

y = minus00089x + 2446

R2 = 0027

(b)

SRI

20

15

10

05

00

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005

y = 00049x minus 926

R2 = 0041

(c)



oqin

g St

atio

nCa

izui

zi S

tatio

nSt

atio

n na

me

Stat

ion

nam

e


0

200

400

600

800

0

200

400

600

800


R2 = 0227

Y = 1523 + 273 lowast X

R2 = 0126


R2 = 0350


R2 = 0338


R2 = 0237

Y = 3734 + 2751 lowast X

R2 = 0047

Y = 4831 + 2224 lowast X

R2 = 0079


R2 = 0490

0 20 40 60 80 0 20 40 60 80 0 20 40 60 80 0 20 40 60 80


Max

flow

(m3s

)M

ax fl

ow (m

3s

)



045

040

035

030

025

30 40 50 60 70 80

SRI

R2 = 098

P lt 001





6 Conclusion







Acknowledgments


References









































Journal of












Volume 2014

Advances in









Geophysics



















Runoff






3 Data and Method





32 Method



Let 1199091 1199092 119909




119895



119905119896=

119896

sum

119894=1

119898119894 (2 le 119896 le 119899) (1)



119905119896= 119864 (119905

119896) =119896 (119896 minus 1)

4

Var (119905119896) =119896 (119896 minus 1) (2119896 + 5)

72

(2)

Let

119906119896=119905119896minus 119905119896

radicvar (119905119896)

(3)









SRI =119877cv119875cv

While 119877cv =119877sd119877avg 119875cv =

119875sd119875avg

(4)


4 Results















R2 = 097R2 = 097 R2 = 084

0

10

20

30

40

50

60

70

80

90

0

10

20

30

40

50

60

70

80

90

Year Year Year

0

1

2

3

4

1954 1976 1986 1995 2000 2005 1954 1976 1986 1995 2000 2005 1954 1976 1986 1995 2000 2005

Are

a (10

4ha

)

Are

a (10

4ha

)

Are

a (10

4ha

)


















0

200

400

600

800

Wet year Dry year

Max

flow

(m3s

)

1000

0

200

400

600

800

1000

Whole time

0

200


0

0 0

200

400

600

0

200

400

600

800

1000

Max

flow

(m3s

)M

ax r

ainf

all (

mm

)

20

40

5060

80

100100

120





Period

Period Period

Period



0

50

100

150

200

1959

1981

Prec

ipita

tion

(mm

)

Month1 2 3 4 5 6 7 8 9 10 11 12


600500400300

100200

0

Runo

ff (m

3s

)

RunoffPrecipitation

50

40

30

20

10

0 Prec

ipita

tion

(mm

)

Day of the year0 50 100 150 200 250 300 350

(a)

600700800

500400300

100200

0

Runo

ff (m

3s

)

RunoffPrecipitation

50

40

30

20

10

0 Prec

ipita

tion

(mm

)

Day of the year0 50 100 150 200 250 300 350

(b)



5 Discussion







CV

6

4

2

0

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005

y = 00087x minus 1646

R2 = 0019

(a)

CV

4

3

2

1

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005

y = minus00089x + 2446

R2 = 0027

(b)

SRI

20

15

10

05

00

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005

y = 00049x minus 926

R2 = 0041

(c)



oqin

g St

atio

nCa

izui

zi S

tatio

nSt

atio

n na

me

Stat

ion

nam

e


0

200

400

600

800

0

200

400

600

800


R2 = 0227

Y = 1523 + 273 lowast X

R2 = 0126


R2 = 0350


R2 = 0338


R2 = 0237

Y = 3734 + 2751 lowast X

R2 = 0047

Y = 4831 + 2224 lowast X

R2 = 0079


R2 = 0490

0 20 40 60 80 0 20 40 60 80 0 20 40 60 80 0 20 40 60 80


Max

flow

(m3s

)M

ax fl

ow (m

3s

)



045

040

035

030

025

30 40 50 60 70 80

SRI

R2 = 098

P lt 001





6 Conclusion







Acknowledgments


References









































Journal of












Volume 2014

Advances in









Geophysics
















119905119896= 119864 (119905

119896) =119896 (119896 minus 1)

4

Var (119905119896) =119896 (119896 minus 1) (2119896 + 5)

72

(2)

Let

119906119896=119905119896minus 119905119896

radicvar (119905119896)

(3)









SRI =119877cv119875cv

While 119877cv =119877sd119877avg 119875cv =

119875sd119875avg

(4)


4 Results















R2 = 097R2 = 097 R2 = 084

0

10

20

30

40

50

60

70

80

90

0

10

20

30

40

50

60

70

80

90

Year Year Year

0

1

2

3

4

1954 1976 1986 1995 2000 2005 1954 1976 1986 1995 2000 2005 1954 1976 1986 1995 2000 2005

Are

a (10

4ha

)

Are

a (10

4ha

)

Are

a (10

4ha

)


















0

200

400

600

800

Wet year Dry year

Max

flow

(m3s

)

1000

0

200

400

600

800

1000

Whole time

0

200


0

0 0

200

400

600

0

200

400

600

800

1000

Max

flow

(m3s

)M

ax r

ainf

all (

mm

)

20

40

5060

80

100100

120





Period

Period Period

Period



0

50

100

150

200

1959

1981

Prec

ipita

tion

(mm

)

Month1 2 3 4 5 6 7 8 9 10 11 12


600500400300

100200

0

Runo

ff (m

3s

)

RunoffPrecipitation

50

40

30

20

10

0 Prec

ipita

tion

(mm

)

Day of the year0 50 100 150 200 250 300 350

(a)

600700800

500400300

100200

0

Runo

ff (m

3s

)

RunoffPrecipitation

50

40

30

20

10

0 Prec

ipita

tion

(mm

)

Day of the year0 50 100 150 200 250 300 350

(b)



5 Discussion







CV

6

4

2

0

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005

y = 00087x minus 1646

R2 = 0019

(a)

CV

4

3

2

1

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005

y = minus00089x + 2446

R2 = 0027

(b)

SRI

20

15

10

05

00

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005

y = 00049x minus 926

R2 = 0041

(c)



oqin

g St

atio

nCa

izui

zi S

tatio

nSt

atio

n na

me

Stat

ion

nam

e


0

200

400

600

800

0

200

400

600

800


R2 = 0227

Y = 1523 + 273 lowast X

R2 = 0126


R2 = 0350


R2 = 0338


R2 = 0237

Y = 3734 + 2751 lowast X

R2 = 0047

Y = 4831 + 2224 lowast X

R2 = 0079


R2 = 0490

0 20 40 60 80 0 20 40 60 80 0 20 40 60 80 0 20 40 60 80


Max

flow

(m3s

)M

ax fl

ow (m

3s

)



045

040

035

030

025

30 40 50 60 70 80

SRI

R2 = 098

P lt 001





6 Conclusion







Acknowledgments


References









































Journal of












Volume 2014

Advances in









Geophysics
















R2 = 097R2 = 097 R2 = 084

0

10

20

30

40

50

60

70

80

90

0

10

20

30

40

50

60

70

80

90

Year Year Year

0

1

2

3

4

1954 1976 1986 1995 2000 2005 1954 1976 1986 1995 2000 2005 1954 1976 1986 1995 2000 2005

Are

a (10

4ha

)

Are

a (10

4ha

)

Are

a (10

4ha

)


















0

200

400

600

800

Wet year Dry year

Max

flow

(m3s

)

1000

0

200

400

600

800

1000

Whole time

0

200


0

0 0

200

400

600

0

200

400

600

800

1000

Max

flow

(m3s

)M

ax r

ainf

all (

mm

)

20

40

5060

80

100100

120





Period

Period Period

Period



0

50

100

150

200

1959

1981

Prec

ipita

tion

(mm

)

Month1 2 3 4 5 6 7 8 9 10 11 12


600500400300

100200

0

Runo

ff (m

3s

)

RunoffPrecipitation

50

40

30

20

10

0 Prec

ipita

tion

(mm

)

Day of the year0 50 100 150 200 250 300 350

(a)

600700800

500400300

100200

0

Runo

ff (m

3s

)

RunoffPrecipitation

50

40

30

20

10

0 Prec

ipita

tion

(mm

)

Day of the year0 50 100 150 200 250 300 350

(b)



5 Discussion







CV

6

4

2

0

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005

y = 00087x minus 1646

R2 = 0019

(a)

CV

4

3

2

1

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005

y = minus00089x + 2446

R2 = 0027

(b)

SRI

20

15

10

05

00

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005

y = 00049x minus 926

R2 = 0041

(c)



oqin

g St

atio

nCa

izui

zi S

tatio

nSt

atio

n na

me

Stat

ion

nam

e


0

200

400

600

800

0

200

400

600

800


R2 = 0227

Y = 1523 + 273 lowast X

R2 = 0126


R2 = 0350


R2 = 0338


R2 = 0237

Y = 3734 + 2751 lowast X

R2 = 0047

Y = 4831 + 2224 lowast X

R2 = 0079


R2 = 0490

0 20 40 60 80 0 20 40 60 80 0 20 40 60 80 0 20 40 60 80


Max

flow

(m3s

)M

ax fl

ow (m

3s

)



045

040

035

030

025

30 40 50 60 70 80

SRI

R2 = 098

P lt 001





6 Conclusion







Acknowledgments


References









































Journal of












Volume 2014

Advances in









Geophysics
















0

200

400

600

800

Wet year Dry year

Max

flow

(m3s

)

1000

0

200

400

600

800

1000

Whole time

0

200


0

0 0

200

400

600

0

200

400

600

800

1000

Max

flow

(m3s

)M

ax r

ainf

all (

mm

)

20

40

5060

80

100100

120





Period

Period Period

Period



0

50

100

150

200

1959

1981

Prec

ipita

tion

(mm

)

Month1 2 3 4 5 6 7 8 9 10 11 12


600500400300

100200

0

Runo

ff (m

3s

)

RunoffPrecipitation

50

40

30

20

10

0 Prec

ipita

tion

(mm

)

Day of the year0 50 100 150 200 250 300 350

(a)

600700800

500400300

100200

0

Runo

ff (m

3s

)

RunoffPrecipitation

50

40

30

20

10

0 Prec

ipita

tion

(mm

)

Day of the year0 50 100 150 200 250 300 350

(b)



5 Discussion







CV

6

4

2

0

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005

y = 00087x minus 1646

R2 = 0019

(a)

CV

4

3

2

1

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005

y = minus00089x + 2446

R2 = 0027

(b)

SRI

20

15

10

05

00

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005

y = 00049x minus 926

R2 = 0041

(c)



oqin

g St

atio

nCa

izui

zi S

tatio

nSt

atio

n na

me

Stat

ion

nam

e


0

200

400

600

800

0

200

400

600

800


R2 = 0227

Y = 1523 + 273 lowast X

R2 = 0126


R2 = 0350


R2 = 0338


R2 = 0237

Y = 3734 + 2751 lowast X

R2 = 0047

Y = 4831 + 2224 lowast X

R2 = 0079


R2 = 0490

0 20 40 60 80 0 20 40 60 80 0 20 40 60 80 0 20 40 60 80


Max

flow

(m3s

)M

ax fl

ow (m

3s

)



045

040

035

030

025

30 40 50 60 70 80

SRI

R2 = 098

P lt 001





6 Conclusion







Acknowledgments


References









































Journal of












Volume 2014

Advances in









Geophysics















0

50

100

150

200

1959

1981

Prec

ipita

tion

(mm

)

Month1 2 3 4 5 6 7 8 9 10 11 12


600500400300

100200

0

Runo

ff (m

3s

)

RunoffPrecipitation

50

40

30

20

10

0 Prec

ipita

tion

(mm

)

Day of the year0 50 100 150 200 250 300 350

(a)

600700800

500400300

100200

0

Runo

ff (m

3s

)

RunoffPrecipitation

50

40

30

20

10

0 Prec

ipita

tion

(mm

)

Day of the year0 50 100 150 200 250 300 350

(b)



5 Discussion







CV

6

4

2

0

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005

y = 00087x minus 1646

R2 = 0019

(a)

CV

4

3

2

1

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005

y = minus00089x + 2446

R2 = 0027

(b)

SRI

20

15

10

05

00

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005

y = 00049x minus 926

R2 = 0041

(c)



oqin

g St

atio

nCa

izui

zi S

tatio

nSt

atio

n na

me

Stat

ion

nam

e


0

200

400

600

800

0

200

400

600

800


R2 = 0227

Y = 1523 + 273 lowast X

R2 = 0126


R2 = 0350


R2 = 0338


R2 = 0237

Y = 3734 + 2751 lowast X

R2 = 0047

Y = 4831 + 2224 lowast X

R2 = 0079


R2 = 0490

0 20 40 60 80 0 20 40 60 80 0 20 40 60 80 0 20 40 60 80


Max

flow

(m3s

)M

ax fl

ow (m

3s

)



045

040

035

030

025

30 40 50 60 70 80

SRI

R2 = 098

P lt 001





6 Conclusion







Acknowledgments


References









































Journal of












Volume 2014

Advances in









Geophysics















CV

6

4

2

0

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005

y = 00087x minus 1646

R2 = 0019

(a)

CV

4

3

2

1

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005

y = minus00089x + 2446

R2 = 0027

(b)

SRI

20

15

10

05

00

1960 1965 1970 1975 1980 1985 1990 1995 2000 2005

y = 00049x minus 926

R2 = 0041

(c)



oqin

g St

atio

nCa

izui

zi S

tatio

nSt

atio

n na

me

Stat

ion

nam

e


0

200

400

600

800

0

200

400

600

800


R2 = 0227

Y = 1523 + 273 lowast X

R2 = 0126


R2 = 0350


R2 = 0338


R2 = 0237

Y = 3734 + 2751 lowast X

R2 = 0047

Y = 4831 + 2224 lowast X

R2 = 0079


R2 = 0490

0 20 40 60 80 0 20 40 60 80 0 20 40 60 80 0 20 40 60 80


Max

flow

(m3s

)M

ax fl

ow (m

3s

)



045

040

035

030

025

30 40 50 60 70 80

SRI

R2 = 098

P lt 001





6 Conclusion







Acknowledgments


References









































Journal of












Volume 2014

Advances in









Geophysics















045

040

035

030

025

30 40 50 60 70 80

SRI

R2 = 098

P lt 001





6 Conclusion







Acknowledgments


References









































Journal of












Volume 2014

Advances in









Geophysics












































Journal of












Volume 2014

Advances in









Geophysics














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